Source file src/reflect/all_test.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package reflect_test
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/base64"
    10  	"flag"
    11  	"fmt"
    12  	"go/token"
    13  	"internal/abi"
    14  	"internal/goarch"
    15  	"internal/testenv"
    16  	"io"
    17  	"math"
    18  	"math/rand"
    19  	"net"
    20  	"os"
    21  	. "reflect"
    22  	"reflect/internal/example1"
    23  	"reflect/internal/example2"
    24  	"runtime"
    25  	"slices"
    26  	"strconv"
    27  	"strings"
    28  	"sync"
    29  	"sync/atomic"
    30  	"testing"
    31  	"time"
    32  	"unsafe"
    33  )
    34  
    35  const bucketCount = abi.MapBucketCount
    36  
    37  var sink any
    38  
    39  func TestBool(t *testing.T) {
    40  	v := ValueOf(true)
    41  	if v.Bool() != true {
    42  		t.Fatal("ValueOf(true).Bool() = false")
    43  	}
    44  }
    45  
    46  type integer int
    47  type T struct {
    48  	a int
    49  	b float64
    50  	c string
    51  	d *int
    52  }
    53  
    54  var _ = T{} == T{} // tests depend on T being comparable
    55  
    56  type pair struct {
    57  	i any
    58  	s string
    59  }
    60  
    61  func assert(t *testing.T, s, want string) {
    62  	if s != want {
    63  		t.Errorf("have %#q want %#q", s, want)
    64  	}
    65  }
    66  
    67  var typeTests = []pair{
    68  	{struct{ x int }{}, "int"},
    69  	{struct{ x int8 }{}, "int8"},
    70  	{struct{ x int16 }{}, "int16"},
    71  	{struct{ x int32 }{}, "int32"},
    72  	{struct{ x int64 }{}, "int64"},
    73  	{struct{ x uint }{}, "uint"},
    74  	{struct{ x uint8 }{}, "uint8"},
    75  	{struct{ x uint16 }{}, "uint16"},
    76  	{struct{ x uint32 }{}, "uint32"},
    77  	{struct{ x uint64 }{}, "uint64"},
    78  	{struct{ x float32 }{}, "float32"},
    79  	{struct{ x float64 }{}, "float64"},
    80  	{struct{ x int8 }{}, "int8"},
    81  	{struct{ x (**int8) }{}, "**int8"},
    82  	{struct{ x (**integer) }{}, "**reflect_test.integer"},
    83  	{struct{ x ([32]int32) }{}, "[32]int32"},
    84  	{struct{ x ([]int8) }{}, "[]int8"},
    85  	{struct{ x (map[string]int32) }{}, "map[string]int32"},
    86  	{struct{ x (chan<- string) }{}, "chan<- string"},
    87  	{struct{ x (chan<- chan string) }{}, "chan<- chan string"},
    88  	{struct{ x (chan<- <-chan string) }{}, "chan<- <-chan string"},
    89  	{struct{ x (<-chan <-chan string) }{}, "<-chan <-chan string"},
    90  	{struct{ x (chan (<-chan string)) }{}, "chan (<-chan string)"},
    91  	{struct {
    92  		x struct {
    93  			c chan *int32
    94  			d float32
    95  		}
    96  	}{},
    97  		"struct { c chan *int32; d float32 }",
    98  	},
    99  	{struct{ x (func(a int8, b int32)) }{}, "func(int8, int32)"},
   100  	{struct {
   101  		x struct {
   102  			c func(chan *integer, *int8)
   103  		}
   104  	}{},
   105  		"struct { c func(chan *reflect_test.integer, *int8) }",
   106  	},
   107  	{struct {
   108  		x struct {
   109  			a int8
   110  			b int32
   111  		}
   112  	}{},
   113  		"struct { a int8; b int32 }",
   114  	},
   115  	{struct {
   116  		x struct {
   117  			a int8
   118  			b int8
   119  			c int32
   120  		}
   121  	}{},
   122  		"struct { a int8; b int8; c int32 }",
   123  	},
   124  	{struct {
   125  		x struct {
   126  			a int8
   127  			b int8
   128  			c int8
   129  			d int32
   130  		}
   131  	}{},
   132  		"struct { a int8; b int8; c int8; d int32 }",
   133  	},
   134  	{struct {
   135  		x struct {
   136  			a int8
   137  			b int8
   138  			c int8
   139  			d int8
   140  			e int32
   141  		}
   142  	}{},
   143  		"struct { a int8; b int8; c int8; d int8; e int32 }",
   144  	},
   145  	{struct {
   146  		x struct {
   147  			a int8
   148  			b int8
   149  			c int8
   150  			d int8
   151  			e int8
   152  			f int32
   153  		}
   154  	}{},
   155  		"struct { a int8; b int8; c int8; d int8; e int8; f int32 }",
   156  	},
   157  	{struct {
   158  		x struct {
   159  			a int8 `reflect:"hi there"`
   160  		}
   161  	}{},
   162  		`struct { a int8 "reflect:\"hi there\"" }`,
   163  	},
   164  	{struct {
   165  		x struct {
   166  			a int8 `reflect:"hi \x00there\t\n\"\\"`
   167  		}
   168  	}{},
   169  		`struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`,
   170  	},
   171  	{struct {
   172  		x struct {
   173  			f func(args ...int)
   174  		}
   175  	}{},
   176  		"struct { f func(...int) }",
   177  	},
   178  	{struct {
   179  		x (interface {
   180  			a(func(func(int) int) func(func(int)) int)
   181  			b()
   182  		})
   183  	}{},
   184  		"interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }",
   185  	},
   186  	{struct {
   187  		x struct {
   188  			int32
   189  			int64
   190  		}
   191  	}{},
   192  		"struct { int32; int64 }",
   193  	},
   194  }
   195  
   196  var valueTests = []pair{
   197  	{new(int), "132"},
   198  	{new(int8), "8"},
   199  	{new(int16), "16"},
   200  	{new(int32), "32"},
   201  	{new(int64), "64"},
   202  	{new(uint), "132"},
   203  	{new(uint8), "8"},
   204  	{new(uint16), "16"},
   205  	{new(uint32), "32"},
   206  	{new(uint64), "64"},
   207  	{new(float32), "256.25"},
   208  	{new(float64), "512.125"},
   209  	{new(complex64), "532.125+10i"},
   210  	{new(complex128), "564.25+1i"},
   211  	{new(string), "stringy cheese"},
   212  	{new(bool), "true"},
   213  	{new(*int8), "*int8(0)"},
   214  	{new(**int8), "**int8(0)"},
   215  	{new([5]int32), "[5]int32{0, 0, 0, 0, 0}"},
   216  	{new(**integer), "**reflect_test.integer(0)"},
   217  	{new(map[string]int32), "map[string]int32{<can't iterate on maps>}"},
   218  	{new(chan<- string), "chan<- string"},
   219  	{new(func(a int8, b int32)), "func(int8, int32)(0)"},
   220  	{new(struct {
   221  		c chan *int32
   222  		d float32
   223  	}),
   224  		"struct { c chan *int32; d float32 }{chan *int32, 0}",
   225  	},
   226  	{new(struct{ c func(chan *integer, *int8) }),
   227  		"struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}",
   228  	},
   229  	{new(struct {
   230  		a int8
   231  		b int32
   232  	}),
   233  		"struct { a int8; b int32 }{0, 0}",
   234  	},
   235  	{new(struct {
   236  		a int8
   237  		b int8
   238  		c int32
   239  	}),
   240  		"struct { a int8; b int8; c int32 }{0, 0, 0}",
   241  	},
   242  }
   243  
   244  func testType(t *testing.T, i int, typ Type, want string) {
   245  	s := typ.String()
   246  	if s != want {
   247  		t.Errorf("#%d: have %#q, want %#q", i, s, want)
   248  	}
   249  }
   250  
   251  func TestTypes(t *testing.T) {
   252  	for i, tt := range typeTests {
   253  		testType(t, i, ValueOf(tt.i).Field(0).Type(), tt.s)
   254  	}
   255  }
   256  
   257  func TestSet(t *testing.T) {
   258  	for i, tt := range valueTests {
   259  		v := ValueOf(tt.i)
   260  		v = v.Elem()
   261  		switch v.Kind() {
   262  		case Int:
   263  			v.SetInt(132)
   264  		case Int8:
   265  			v.SetInt(8)
   266  		case Int16:
   267  			v.SetInt(16)
   268  		case Int32:
   269  			v.SetInt(32)
   270  		case Int64:
   271  			v.SetInt(64)
   272  		case Uint:
   273  			v.SetUint(132)
   274  		case Uint8:
   275  			v.SetUint(8)
   276  		case Uint16:
   277  			v.SetUint(16)
   278  		case Uint32:
   279  			v.SetUint(32)
   280  		case Uint64:
   281  			v.SetUint(64)
   282  		case Float32:
   283  			v.SetFloat(256.25)
   284  		case Float64:
   285  			v.SetFloat(512.125)
   286  		case Complex64:
   287  			v.SetComplex(532.125 + 10i)
   288  		case Complex128:
   289  			v.SetComplex(564.25 + 1i)
   290  		case String:
   291  			v.SetString("stringy cheese")
   292  		case Bool:
   293  			v.SetBool(true)
   294  		}
   295  		s := valueToString(v)
   296  		if s != tt.s {
   297  			t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
   298  		}
   299  	}
   300  }
   301  
   302  func TestSetValue(t *testing.T) {
   303  	for i, tt := range valueTests {
   304  		v := ValueOf(tt.i).Elem()
   305  		switch v.Kind() {
   306  		case Int:
   307  			v.Set(ValueOf(int(132)))
   308  		case Int8:
   309  			v.Set(ValueOf(int8(8)))
   310  		case Int16:
   311  			v.Set(ValueOf(int16(16)))
   312  		case Int32:
   313  			v.Set(ValueOf(int32(32)))
   314  		case Int64:
   315  			v.Set(ValueOf(int64(64)))
   316  		case Uint:
   317  			v.Set(ValueOf(uint(132)))
   318  		case Uint8:
   319  			v.Set(ValueOf(uint8(8)))
   320  		case Uint16:
   321  			v.Set(ValueOf(uint16(16)))
   322  		case Uint32:
   323  			v.Set(ValueOf(uint32(32)))
   324  		case Uint64:
   325  			v.Set(ValueOf(uint64(64)))
   326  		case Float32:
   327  			v.Set(ValueOf(float32(256.25)))
   328  		case Float64:
   329  			v.Set(ValueOf(512.125))
   330  		case Complex64:
   331  			v.Set(ValueOf(complex64(532.125 + 10i)))
   332  		case Complex128:
   333  			v.Set(ValueOf(complex128(564.25 + 1i)))
   334  		case String:
   335  			v.Set(ValueOf("stringy cheese"))
   336  		case Bool:
   337  			v.Set(ValueOf(true))
   338  		}
   339  		s := valueToString(v)
   340  		if s != tt.s {
   341  			t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
   342  		}
   343  	}
   344  }
   345  
   346  func TestMapIterSet(t *testing.T) {
   347  	m := make(map[string]any, len(valueTests))
   348  	for _, tt := range valueTests {
   349  		m[tt.s] = tt.i
   350  	}
   351  	v := ValueOf(m)
   352  
   353  	k := New(v.Type().Key()).Elem()
   354  	e := New(v.Type().Elem()).Elem()
   355  
   356  	iter := v.MapRange()
   357  	for iter.Next() {
   358  		k.SetIterKey(iter)
   359  		e.SetIterValue(iter)
   360  		want := m[k.String()]
   361  		got := e.Interface()
   362  		if got != want {
   363  			t.Errorf("%q: want (%T) %v, got (%T) %v", k.String(), want, want, got, got)
   364  		}
   365  		if setkey, key := valueToString(k), valueToString(iter.Key()); setkey != key {
   366  			t.Errorf("MapIter.Key() = %q, MapIter.SetKey() = %q", key, setkey)
   367  		}
   368  		if setval, val := valueToString(e), valueToString(iter.Value()); setval != val {
   369  			t.Errorf("MapIter.Value() = %q, MapIter.SetValue() = %q", val, setval)
   370  		}
   371  	}
   372  
   373  	if testenv.OptimizationOff() {
   374  		return // no inlining with the noopt builder
   375  	}
   376  
   377  	got := int(testing.AllocsPerRun(10, func() {
   378  		iter := v.MapRange()
   379  		for iter.Next() {
   380  			k.SetIterKey(iter)
   381  			e.SetIterValue(iter)
   382  		}
   383  	}))
   384  	// Calling MapRange should not allocate even though it returns a *MapIter.
   385  	// The function is inlineable, so if the local usage does not escape
   386  	// the *MapIter, it can remain stack allocated.
   387  	want := 0
   388  	if got != want {
   389  		t.Errorf("wanted %d alloc, got %d", want, got)
   390  	}
   391  }
   392  
   393  func TestCanIntUintFloatComplex(t *testing.T) {
   394  	type integer int
   395  	type uinteger uint
   396  	type float float64
   397  	type complex complex128
   398  
   399  	var ops = [...]string{"CanInt", "CanUint", "CanFloat", "CanComplex"}
   400  
   401  	var testCases = []struct {
   402  		i    any
   403  		want [4]bool
   404  	}{
   405  		// signed integer
   406  		{132, [...]bool{true, false, false, false}},
   407  		{int8(8), [...]bool{true, false, false, false}},
   408  		{int16(16), [...]bool{true, false, false, false}},
   409  		{int32(32), [...]bool{true, false, false, false}},
   410  		{int64(64), [...]bool{true, false, false, false}},
   411  		// unsigned integer
   412  		{uint(132), [...]bool{false, true, false, false}},
   413  		{uint8(8), [...]bool{false, true, false, false}},
   414  		{uint16(16), [...]bool{false, true, false, false}},
   415  		{uint32(32), [...]bool{false, true, false, false}},
   416  		{uint64(64), [...]bool{false, true, false, false}},
   417  		{uintptr(0xABCD), [...]bool{false, true, false, false}},
   418  		// floating-point
   419  		{float32(256.25), [...]bool{false, false, true, false}},
   420  		{float64(512.125), [...]bool{false, false, true, false}},
   421  		// complex
   422  		{complex64(532.125 + 10i), [...]bool{false, false, false, true}},
   423  		{complex128(564.25 + 1i), [...]bool{false, false, false, true}},
   424  		// underlying
   425  		{integer(-132), [...]bool{true, false, false, false}},
   426  		{uinteger(132), [...]bool{false, true, false, false}},
   427  		{float(256.25), [...]bool{false, false, true, false}},
   428  		{complex(532.125 + 10i), [...]bool{false, false, false, true}},
   429  		// not-acceptable
   430  		{"hello world", [...]bool{false, false, false, false}},
   431  		{new(int), [...]bool{false, false, false, false}},
   432  		{new(uint), [...]bool{false, false, false, false}},
   433  		{new(float64), [...]bool{false, false, false, false}},
   434  		{new(complex64), [...]bool{false, false, false, false}},
   435  		{new([5]int), [...]bool{false, false, false, false}},
   436  		{new(integer), [...]bool{false, false, false, false}},
   437  		{new(map[int]int), [...]bool{false, false, false, false}},
   438  		{new(chan<- int), [...]bool{false, false, false, false}},
   439  		{new(func(a int8)), [...]bool{false, false, false, false}},
   440  		{new(struct{ i int }), [...]bool{false, false, false, false}},
   441  	}
   442  
   443  	for i, tc := range testCases {
   444  		v := ValueOf(tc.i)
   445  		got := [...]bool{v.CanInt(), v.CanUint(), v.CanFloat(), v.CanComplex()}
   446  
   447  		for j := range tc.want {
   448  			if got[j] != tc.want[j] {
   449  				t.Errorf(
   450  					"#%d: v.%s() returned %t for type %T, want %t",
   451  					i,
   452  					ops[j],
   453  					got[j],
   454  					tc.i,
   455  					tc.want[j],
   456  				)
   457  			}
   458  		}
   459  	}
   460  }
   461  
   462  func TestCanSetField(t *testing.T) {
   463  	type embed struct{ x, X int }
   464  	type Embed struct{ x, X int }
   465  	type S1 struct {
   466  		embed
   467  		x, X int
   468  	}
   469  	type S2 struct {
   470  		*embed
   471  		x, X int
   472  	}
   473  	type S3 struct {
   474  		Embed
   475  		x, X int
   476  	}
   477  	type S4 struct {
   478  		*Embed
   479  		x, X int
   480  	}
   481  
   482  	type testCase struct {
   483  		// -1 means Addr().Elem() of current value
   484  		index  []int
   485  		canSet bool
   486  	}
   487  	tests := []struct {
   488  		val   Value
   489  		cases []testCase
   490  	}{{
   491  		val: ValueOf(&S1{}),
   492  		cases: []testCase{
   493  			{[]int{0}, false},
   494  			{[]int{0, -1}, false},
   495  			{[]int{0, 0}, false},
   496  			{[]int{0, 0, -1}, false},
   497  			{[]int{0, -1, 0}, false},
   498  			{[]int{0, -1, 0, -1}, false},
   499  			{[]int{0, 1}, true},
   500  			{[]int{0, 1, -1}, true},
   501  			{[]int{0, -1, 1}, true},
   502  			{[]int{0, -1, 1, -1}, true},
   503  			{[]int{1}, false},
   504  			{[]int{1, -1}, false},
   505  			{[]int{2}, true},
   506  			{[]int{2, -1}, true},
   507  		},
   508  	}, {
   509  		val: ValueOf(&S2{embed: &embed{}}),
   510  		cases: []testCase{
   511  			{[]int{0}, false},
   512  			{[]int{0, -1}, false},
   513  			{[]int{0, 0}, false},
   514  			{[]int{0, 0, -1}, false},
   515  			{[]int{0, -1, 0}, false},
   516  			{[]int{0, -1, 0, -1}, false},
   517  			{[]int{0, 1}, true},
   518  			{[]int{0, 1, -1}, true},
   519  			{[]int{0, -1, 1}, true},
   520  			{[]int{0, -1, 1, -1}, true},
   521  			{[]int{1}, false},
   522  			{[]int{2}, true},
   523  		},
   524  	}, {
   525  		val: ValueOf(&S3{}),
   526  		cases: []testCase{
   527  			{[]int{0}, true},
   528  			{[]int{0, -1}, true},
   529  			{[]int{0, 0}, false},
   530  			{[]int{0, 0, -1}, false},
   531  			{[]int{0, -1, 0}, false},
   532  			{[]int{0, -1, 0, -1}, false},
   533  			{[]int{0, 1}, true},
   534  			{[]int{0, 1, -1}, true},
   535  			{[]int{0, -1, 1}, true},
   536  			{[]int{0, -1, 1, -1}, true},
   537  			{[]int{1}, false},
   538  			{[]int{2}, true},
   539  		},
   540  	}, {
   541  		val: ValueOf(&S4{Embed: &Embed{}}),
   542  		cases: []testCase{
   543  			{[]int{0}, true},
   544  			{[]int{0, -1}, true},
   545  			{[]int{0, 0}, false},
   546  			{[]int{0, 0, -1}, false},
   547  			{[]int{0, -1, 0}, false},
   548  			{[]int{0, -1, 0, -1}, false},
   549  			{[]int{0, 1}, true},
   550  			{[]int{0, 1, -1}, true},
   551  			{[]int{0, -1, 1}, true},
   552  			{[]int{0, -1, 1, -1}, true},
   553  			{[]int{1}, false},
   554  			{[]int{2}, true},
   555  		},
   556  	}}
   557  
   558  	for _, tt := range tests {
   559  		t.Run(tt.val.Type().Name(), func(t *testing.T) {
   560  			for _, tc := range tt.cases {
   561  				f := tt.val
   562  				for _, i := range tc.index {
   563  					if f.Kind() == Pointer {
   564  						f = f.Elem()
   565  					}
   566  					if i == -1 {
   567  						f = f.Addr().Elem()
   568  					} else {
   569  						f = f.Field(i)
   570  					}
   571  				}
   572  				if got := f.CanSet(); got != tc.canSet {
   573  					t.Errorf("CanSet() = %v, want %v", got, tc.canSet)
   574  				}
   575  			}
   576  		})
   577  	}
   578  }
   579  
   580  var _i = 7
   581  
   582  var valueToStringTests = []pair{
   583  	{123, "123"},
   584  	{123.5, "123.5"},
   585  	{byte(123), "123"},
   586  	{"abc", "abc"},
   587  	{T{123, 456.75, "hello", &_i}, "reflect_test.T{123, 456.75, hello, *int(&7)}"},
   588  	{new(chan *T), "*chan *reflect_test.T(&chan *reflect_test.T)"},
   589  	{[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
   590  	{&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[10]int(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
   591  	{[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
   592  	{&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[]int(&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
   593  }
   594  
   595  func TestValueToString(t *testing.T) {
   596  	for i, test := range valueToStringTests {
   597  		s := valueToString(ValueOf(test.i))
   598  		if s != test.s {
   599  			t.Errorf("#%d: have %#q, want %#q", i, s, test.s)
   600  		}
   601  	}
   602  }
   603  
   604  func TestArrayElemSet(t *testing.T) {
   605  	v := ValueOf(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).Elem()
   606  	v.Index(4).SetInt(123)
   607  	s := valueToString(v)
   608  	const want = "[10]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
   609  	if s != want {
   610  		t.Errorf("[10]int: have %#q want %#q", s, want)
   611  	}
   612  
   613  	v = ValueOf([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
   614  	v.Index(4).SetInt(123)
   615  	s = valueToString(v)
   616  	const want1 = "[]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
   617  	if s != want1 {
   618  		t.Errorf("[]int: have %#q want %#q", s, want1)
   619  	}
   620  }
   621  
   622  func TestPtrPointTo(t *testing.T) {
   623  	var ip *int32
   624  	var i int32 = 1234
   625  	vip := ValueOf(&ip)
   626  	vi := ValueOf(&i).Elem()
   627  	vip.Elem().Set(vi.Addr())
   628  	if *ip != 1234 {
   629  		t.Errorf("got %d, want 1234", *ip)
   630  	}
   631  
   632  	ip = nil
   633  	vp := ValueOf(&ip).Elem()
   634  	vp.Set(Zero(vp.Type()))
   635  	if ip != nil {
   636  		t.Errorf("got non-nil (%p), want nil", ip)
   637  	}
   638  }
   639  
   640  func TestPtrSetNil(t *testing.T) {
   641  	var i int32 = 1234
   642  	ip := &i
   643  	vip := ValueOf(&ip)
   644  	vip.Elem().Set(Zero(vip.Elem().Type()))
   645  	if ip != nil {
   646  		t.Errorf("got non-nil (%d), want nil", *ip)
   647  	}
   648  }
   649  
   650  func TestMapSetNil(t *testing.T) {
   651  	m := make(map[string]int)
   652  	vm := ValueOf(&m)
   653  	vm.Elem().Set(Zero(vm.Elem().Type()))
   654  	if m != nil {
   655  		t.Errorf("got non-nil (%p), want nil", m)
   656  	}
   657  }
   658  
   659  func TestAll(t *testing.T) {
   660  	testType(t, 1, TypeOf((int8)(0)), "int8")
   661  	testType(t, 2, TypeOf((*int8)(nil)).Elem(), "int8")
   662  
   663  	typ := TypeOf((*struct {
   664  		c chan *int32
   665  		d float32
   666  	})(nil))
   667  	testType(t, 3, typ, "*struct { c chan *int32; d float32 }")
   668  	etyp := typ.Elem()
   669  	testType(t, 4, etyp, "struct { c chan *int32; d float32 }")
   670  	styp := etyp
   671  	f := styp.Field(0)
   672  	testType(t, 5, f.Type, "chan *int32")
   673  
   674  	f, present := styp.FieldByName("d")
   675  	if !present {
   676  		t.Errorf("FieldByName says present field is absent")
   677  	}
   678  	testType(t, 6, f.Type, "float32")
   679  
   680  	f, present = styp.FieldByName("absent")
   681  	if present {
   682  		t.Errorf("FieldByName says absent field is present")
   683  	}
   684  
   685  	typ = TypeOf([32]int32{})
   686  	testType(t, 7, typ, "[32]int32")
   687  	testType(t, 8, typ.Elem(), "int32")
   688  
   689  	typ = TypeOf((map[string]*int32)(nil))
   690  	testType(t, 9, typ, "map[string]*int32")
   691  	mtyp := typ
   692  	testType(t, 10, mtyp.Key(), "string")
   693  	testType(t, 11, mtyp.Elem(), "*int32")
   694  
   695  	typ = TypeOf((chan<- string)(nil))
   696  	testType(t, 12, typ, "chan<- string")
   697  	testType(t, 13, typ.Elem(), "string")
   698  
   699  	// make sure tag strings are not part of element type
   700  	typ = TypeOf(struct {
   701  		d []uint32 `reflect:"TAG"`
   702  	}{}).Field(0).Type
   703  	testType(t, 14, typ, "[]uint32")
   704  }
   705  
   706  func TestInterfaceGet(t *testing.T) {
   707  	var inter struct {
   708  		E any
   709  	}
   710  	inter.E = 123.456
   711  	v1 := ValueOf(&inter)
   712  	v2 := v1.Elem().Field(0)
   713  	assert(t, v2.Type().String(), "interface {}")
   714  	i2 := v2.Interface()
   715  	v3 := ValueOf(i2)
   716  	assert(t, v3.Type().String(), "float64")
   717  }
   718  
   719  func TestInterfaceValue(t *testing.T) {
   720  	var inter struct {
   721  		E any
   722  	}
   723  	inter.E = 123.456
   724  	v1 := ValueOf(&inter)
   725  	v2 := v1.Elem().Field(0)
   726  	assert(t, v2.Type().String(), "interface {}")
   727  	v3 := v2.Elem()
   728  	assert(t, v3.Type().String(), "float64")
   729  
   730  	i3 := v2.Interface()
   731  	if _, ok := i3.(float64); !ok {
   732  		t.Error("v2.Interface() did not return float64, got ", TypeOf(i3))
   733  	}
   734  }
   735  
   736  func TestFunctionValue(t *testing.T) {
   737  	var x any = func() {}
   738  	v := ValueOf(x)
   739  	if fmt.Sprint(v.Interface()) != fmt.Sprint(x) {
   740  		t.Fatalf("TestFunction returned wrong pointer")
   741  	}
   742  	assert(t, v.Type().String(), "func()")
   743  }
   744  
   745  func TestGrow(t *testing.T) {
   746  	v := ValueOf([]int(nil))
   747  	shouldPanic("reflect.Value.Grow using unaddressable value", func() { v.Grow(0) })
   748  	v = ValueOf(new([]int)).Elem()
   749  	v.Grow(0)
   750  	if !v.IsNil() {
   751  		t.Errorf("v.Grow(0) should still be nil")
   752  	}
   753  	v.Grow(1)
   754  	if v.Cap() == 0 {
   755  		t.Errorf("v.Cap = %v, want non-zero", v.Cap())
   756  	}
   757  	want := v.UnsafePointer()
   758  	v.Grow(1)
   759  	got := v.UnsafePointer()
   760  	if got != want {
   761  		t.Errorf("noop v.Grow should not change pointers")
   762  	}
   763  
   764  	t.Run("Append", func(t *testing.T) {
   765  		var got, want []T
   766  		v := ValueOf(&got).Elem()
   767  		appendValue := func(vt T) {
   768  			v.Grow(1)
   769  			v.SetLen(v.Len() + 1)
   770  			v.Index(v.Len() - 1).Set(ValueOf(vt))
   771  		}
   772  		for i := 0; i < 10; i++ {
   773  			vt := T{i, float64(i), strconv.Itoa(i), &i}
   774  			appendValue(vt)
   775  			want = append(want, vt)
   776  		}
   777  		if !DeepEqual(got, want) {
   778  			t.Errorf("value mismatch:\ngot  %v\nwant %v", got, want)
   779  		}
   780  	})
   781  
   782  	t.Run("Rate", func(t *testing.T) {
   783  		var b []byte
   784  		v := ValueOf(new([]byte)).Elem()
   785  		for i := 0; i < 10; i++ {
   786  			b = append(b[:cap(b)], make([]byte, 1)...)
   787  			v.SetLen(v.Cap())
   788  			v.Grow(1)
   789  			if v.Cap() != cap(b) {
   790  				t.Errorf("v.Cap = %v, want %v", v.Cap(), cap(b))
   791  			}
   792  		}
   793  	})
   794  
   795  	t.Run("ZeroCapacity", func(t *testing.T) {
   796  		for i := 0; i < 10; i++ {
   797  			v := ValueOf(new([]byte)).Elem()
   798  			v.Grow(61)
   799  			b := v.Bytes()
   800  			b = b[:cap(b)]
   801  			for i, c := range b {
   802  				if c != 0 {
   803  					t.Fatalf("Value.Bytes[%d] = 0x%02x, want 0x00", i, c)
   804  				}
   805  				b[i] = 0xff
   806  			}
   807  			runtime.GC()
   808  		}
   809  	})
   810  }
   811  
   812  var appendTests = []struct {
   813  	orig, extra []int
   814  }{
   815  	{nil, nil},
   816  	{[]int{}, nil},
   817  	{nil, []int{}},
   818  	{[]int{}, []int{}},
   819  	{nil, []int{22}},
   820  	{[]int{}, []int{22}},
   821  	{make([]int, 2, 4), nil},
   822  	{make([]int, 2, 4), []int{}},
   823  	{make([]int, 2, 4), []int{22}},
   824  	{make([]int, 2, 4), []int{22, 33, 44}},
   825  }
   826  
   827  func TestAppend(t *testing.T) {
   828  	for i, test := range appendTests {
   829  		origLen, extraLen := len(test.orig), len(test.extra)
   830  		want := append(test.orig, test.extra...)
   831  		// Convert extra from []int to []Value.
   832  		e0 := make([]Value, len(test.extra))
   833  		for j, e := range test.extra {
   834  			e0[j] = ValueOf(e)
   835  		}
   836  		// Convert extra from []int to *SliceValue.
   837  		e1 := ValueOf(test.extra)
   838  
   839  		// Test Append.
   840  		a0 := ValueOf(&test.orig).Elem()
   841  		have0 := Append(a0, e0...)
   842  		if have0.CanAddr() {
   843  			t.Errorf("Append #%d: have slice should not be addressable", i)
   844  		}
   845  		if !DeepEqual(have0.Interface(), want) {
   846  			t.Errorf("Append #%d: have %v, want %v (%p %p)", i, have0, want, test.orig, have0.Interface())
   847  		}
   848  		// Check that the orig and extra slices were not modified.
   849  		if a0.Len() != len(test.orig) {
   850  			t.Errorf("Append #%d: a0.Len: have %d, want %d", i, a0.Len(), origLen)
   851  		}
   852  		if len(test.orig) != origLen {
   853  			t.Errorf("Append #%d origLen: have %v, want %v", i, len(test.orig), origLen)
   854  		}
   855  		if len(test.extra) != extraLen {
   856  			t.Errorf("Append #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
   857  		}
   858  
   859  		// Test AppendSlice.
   860  		a1 := ValueOf(&test.orig).Elem()
   861  		have1 := AppendSlice(a1, e1)
   862  		if have1.CanAddr() {
   863  			t.Errorf("AppendSlice #%d: have slice should not be addressable", i)
   864  		}
   865  		if !DeepEqual(have1.Interface(), want) {
   866  			t.Errorf("AppendSlice #%d: have %v, want %v", i, have1, want)
   867  		}
   868  		// Check that the orig and extra slices were not modified.
   869  		if a1.Len() != len(test.orig) {
   870  			t.Errorf("AppendSlice #%d: a1.Len: have %d, want %d", i, a0.Len(), origLen)
   871  		}
   872  		if len(test.orig) != origLen {
   873  			t.Errorf("AppendSlice #%d origLen: have %v, want %v", i, len(test.orig), origLen)
   874  		}
   875  		if len(test.extra) != extraLen {
   876  			t.Errorf("AppendSlice #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
   877  		}
   878  
   879  		// Test Append and AppendSlice with unexported value.
   880  		ax := ValueOf(struct{ x []int }{test.orig}).Field(0)
   881  		shouldPanic("using unexported field", func() { Append(ax, e0...) })
   882  		shouldPanic("using unexported field", func() { AppendSlice(ax, e1) })
   883  	}
   884  }
   885  
   886  func TestCopy(t *testing.T) {
   887  	a := []int{1, 2, 3, 4, 10, 9, 8, 7}
   888  	b := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
   889  	c := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
   890  	for i := 0; i < len(b); i++ {
   891  		if b[i] != c[i] {
   892  			t.Fatalf("b != c before test")
   893  		}
   894  	}
   895  	a1 := a
   896  	b1 := b
   897  	aa := ValueOf(&a1).Elem()
   898  	ab := ValueOf(&b1).Elem()
   899  	for tocopy := 1; tocopy <= 7; tocopy++ {
   900  		aa.SetLen(tocopy)
   901  		Copy(ab, aa)
   902  		aa.SetLen(8)
   903  		for i := 0; i < tocopy; i++ {
   904  			if a[i] != b[i] {
   905  				t.Errorf("(i) tocopy=%d a[%d]=%d, b[%d]=%d",
   906  					tocopy, i, a[i], i, b[i])
   907  			}
   908  		}
   909  		for i := tocopy; i < len(b); i++ {
   910  			if b[i] != c[i] {
   911  				if i < len(a) {
   912  					t.Errorf("(ii) tocopy=%d a[%d]=%d, b[%d]=%d, c[%d]=%d",
   913  						tocopy, i, a[i], i, b[i], i, c[i])
   914  				} else {
   915  					t.Errorf("(iii) tocopy=%d b[%d]=%d, c[%d]=%d",
   916  						tocopy, i, b[i], i, c[i])
   917  				}
   918  			} else {
   919  				t.Logf("tocopy=%d elem %d is okay\n", tocopy, i)
   920  			}
   921  		}
   922  	}
   923  }
   924  
   925  func TestCopyString(t *testing.T) {
   926  	t.Run("Slice", func(t *testing.T) {
   927  		s := bytes.Repeat([]byte{'_'}, 8)
   928  		val := ValueOf(s)
   929  
   930  		n := Copy(val, ValueOf(""))
   931  		if expecting := []byte("________"); n != 0 || !bytes.Equal(s, expecting) {
   932  			t.Errorf("got n = %d, s = %s, expecting n = 0, s = %s", n, s, expecting)
   933  		}
   934  
   935  		n = Copy(val, ValueOf("hello"))
   936  		if expecting := []byte("hello___"); n != 5 || !bytes.Equal(s, expecting) {
   937  			t.Errorf("got n = %d, s = %s, expecting n = 5, s = %s", n, s, expecting)
   938  		}
   939  
   940  		n = Copy(val, ValueOf("helloworld"))
   941  		if expecting := []byte("hellowor"); n != 8 || !bytes.Equal(s, expecting) {
   942  			t.Errorf("got n = %d, s = %s, expecting n = 8, s = %s", n, s, expecting)
   943  		}
   944  	})
   945  	t.Run("Array", func(t *testing.T) {
   946  		s := [...]byte{'_', '_', '_', '_', '_', '_', '_', '_'}
   947  		val := ValueOf(&s).Elem()
   948  
   949  		n := Copy(val, ValueOf(""))
   950  		if expecting := []byte("________"); n != 0 || !bytes.Equal(s[:], expecting) {
   951  			t.Errorf("got n = %d, s = %s, expecting n = 0, s = %s", n, s[:], expecting)
   952  		}
   953  
   954  		n = Copy(val, ValueOf("hello"))
   955  		if expecting := []byte("hello___"); n != 5 || !bytes.Equal(s[:], expecting) {
   956  			t.Errorf("got n = %d, s = %s, expecting n = 5, s = %s", n, s[:], expecting)
   957  		}
   958  
   959  		n = Copy(val, ValueOf("helloworld"))
   960  		if expecting := []byte("hellowor"); n != 8 || !bytes.Equal(s[:], expecting) {
   961  			t.Errorf("got n = %d, s = %s, expecting n = 8, s = %s", n, s[:], expecting)
   962  		}
   963  	})
   964  }
   965  
   966  func TestCopyArray(t *testing.T) {
   967  	a := [8]int{1, 2, 3, 4, 10, 9, 8, 7}
   968  	b := [11]int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
   969  	c := b
   970  	aa := ValueOf(&a).Elem()
   971  	ab := ValueOf(&b).Elem()
   972  	Copy(ab, aa)
   973  	for i := 0; i < len(a); i++ {
   974  		if a[i] != b[i] {
   975  			t.Errorf("(i) a[%d]=%d, b[%d]=%d", i, a[i], i, b[i])
   976  		}
   977  	}
   978  	for i := len(a); i < len(b); i++ {
   979  		if b[i] != c[i] {
   980  			t.Errorf("(ii) b[%d]=%d, c[%d]=%d", i, b[i], i, c[i])
   981  		} else {
   982  			t.Logf("elem %d is okay\n", i)
   983  		}
   984  	}
   985  }
   986  
   987  func TestBigUnnamedStruct(t *testing.T) {
   988  	b := struct{ a, b, c, d int64 }{1, 2, 3, 4}
   989  	v := ValueOf(b)
   990  	b1 := v.Interface().(struct {
   991  		a, b, c, d int64
   992  	})
   993  	if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d {
   994  		t.Errorf("ValueOf(%v).Interface().(*Big) = %v", b, b1)
   995  	}
   996  }
   997  
   998  type big struct {
   999  	a, b, c, d, e int64
  1000  }
  1001  
  1002  func TestBigStruct(t *testing.T) {
  1003  	b := big{1, 2, 3, 4, 5}
  1004  	v := ValueOf(b)
  1005  	b1 := v.Interface().(big)
  1006  	if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d || b1.e != b.e {
  1007  		t.Errorf("ValueOf(%v).Interface().(big) = %v", b, b1)
  1008  	}
  1009  }
  1010  
  1011  type Basic struct {
  1012  	x int
  1013  	y float32
  1014  }
  1015  
  1016  type NotBasic Basic
  1017  
  1018  type DeepEqualTest struct {
  1019  	a, b any
  1020  	eq   bool
  1021  }
  1022  
  1023  // Simple functions for DeepEqual tests.
  1024  var (
  1025  	fn1 func()             // nil.
  1026  	fn2 func()             // nil.
  1027  	fn3 = func() { fn1() } // Not nil.
  1028  )
  1029  
  1030  type self struct{}
  1031  
  1032  type Loop *Loop
  1033  type Loopy any
  1034  
  1035  var loop1, loop2 Loop
  1036  var loopy1, loopy2 Loopy
  1037  var cycleMap1, cycleMap2, cycleMap3 map[string]any
  1038  
  1039  type structWithSelfPtr struct {
  1040  	p *structWithSelfPtr
  1041  	s string
  1042  }
  1043  
  1044  func init() {
  1045  	loop1 = &loop2
  1046  	loop2 = &loop1
  1047  
  1048  	loopy1 = &loopy2
  1049  	loopy2 = &loopy1
  1050  
  1051  	cycleMap1 = map[string]any{}
  1052  	cycleMap1["cycle"] = cycleMap1
  1053  	cycleMap2 = map[string]any{}
  1054  	cycleMap2["cycle"] = cycleMap2
  1055  	cycleMap3 = map[string]any{}
  1056  	cycleMap3["different"] = cycleMap3
  1057  }
  1058  
  1059  var deepEqualTests = []DeepEqualTest{
  1060  	// Equalities
  1061  	{nil, nil, true},
  1062  	{1, 1, true},
  1063  	{int32(1), int32(1), true},
  1064  	{0.5, 0.5, true},
  1065  	{float32(0.5), float32(0.5), true},
  1066  	{"hello", "hello", true},
  1067  	{make([]int, 10), make([]int, 10), true},
  1068  	{&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true},
  1069  	{Basic{1, 0.5}, Basic{1, 0.5}, true},
  1070  	{error(nil), error(nil), true},
  1071  	{map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true},
  1072  	{fn1, fn2, true},
  1073  	{[]byte{1, 2, 3}, []byte{1, 2, 3}, true},
  1074  	{[]MyByte{1, 2, 3}, []MyByte{1, 2, 3}, true},
  1075  	{MyBytes{1, 2, 3}, MyBytes{1, 2, 3}, true},
  1076  
  1077  	// Inequalities
  1078  	{1, 2, false},
  1079  	{int32(1), int32(2), false},
  1080  	{0.5, 0.6, false},
  1081  	{float32(0.5), float32(0.6), false},
  1082  	{"hello", "hey", false},
  1083  	{make([]int, 10), make([]int, 11), false},
  1084  	{&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false},
  1085  	{Basic{1, 0.5}, Basic{1, 0.6}, false},
  1086  	{Basic{1, 0}, Basic{2, 0}, false},
  1087  	{map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false},
  1088  	{map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false},
  1089  	{map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false},
  1090  	{map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false},
  1091  	{nil, 1, false},
  1092  	{1, nil, false},
  1093  	{fn1, fn3, false},
  1094  	{fn3, fn3, false},
  1095  	{[][]int{{1}}, [][]int{{2}}, false},
  1096  	{&structWithSelfPtr{p: &structWithSelfPtr{s: "a"}}, &structWithSelfPtr{p: &structWithSelfPtr{s: "b"}}, false},
  1097  
  1098  	// Fun with floating point.
  1099  	{math.NaN(), math.NaN(), false},
  1100  	{&[1]float64{math.NaN()}, &[1]float64{math.NaN()}, false},
  1101  	{&[1]float64{math.NaN()}, self{}, true},
  1102  	{[]float64{math.NaN()}, []float64{math.NaN()}, false},
  1103  	{[]float64{math.NaN()}, self{}, true},
  1104  	{map[float64]float64{math.NaN(): 1}, map[float64]float64{1: 2}, false},
  1105  	{map[float64]float64{math.NaN(): 1}, self{}, true},
  1106  
  1107  	// Nil vs empty: not the same.
  1108  	{[]int{}, []int(nil), false},
  1109  	{[]int{}, []int{}, true},
  1110  	{[]int(nil), []int(nil), true},
  1111  	{map[int]int{}, map[int]int(nil), false},
  1112  	{map[int]int{}, map[int]int{}, true},
  1113  	{map[int]int(nil), map[int]int(nil), true},
  1114  
  1115  	// Mismatched types
  1116  	{1, 1.0, false},
  1117  	{int32(1), int64(1), false},
  1118  	{0.5, "hello", false},
  1119  	{[]int{1, 2, 3}, [3]int{1, 2, 3}, false},
  1120  	{&[3]any{1, 2, 4}, &[3]any{1, 2, "s"}, false},
  1121  	{Basic{1, 0.5}, NotBasic{1, 0.5}, false},
  1122  	{map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false},
  1123  	{[]byte{1, 2, 3}, []MyByte{1, 2, 3}, false},
  1124  	{[]MyByte{1, 2, 3}, MyBytes{1, 2, 3}, false},
  1125  	{[]byte{1, 2, 3}, MyBytes{1, 2, 3}, false},
  1126  
  1127  	// Possible loops.
  1128  	{&loop1, &loop1, true},
  1129  	{&loop1, &loop2, true},
  1130  	{&loopy1, &loopy1, true},
  1131  	{&loopy1, &loopy2, true},
  1132  	{&cycleMap1, &cycleMap2, true},
  1133  	{&cycleMap1, &cycleMap3, false},
  1134  }
  1135  
  1136  func TestDeepEqual(t *testing.T) {
  1137  	for _, test := range deepEqualTests {
  1138  		if test.b == (self{}) {
  1139  			test.b = test.a
  1140  		}
  1141  		if r := DeepEqual(test.a, test.b); r != test.eq {
  1142  			t.Errorf("DeepEqual(%#v, %#v) = %v, want %v", test.a, test.b, r, test.eq)
  1143  		}
  1144  	}
  1145  }
  1146  
  1147  func TestTypeOf(t *testing.T) {
  1148  	// Special case for nil
  1149  	if typ := TypeOf(nil); typ != nil {
  1150  		t.Errorf("expected nil type for nil value; got %v", typ)
  1151  	}
  1152  	for _, test := range deepEqualTests {
  1153  		v := ValueOf(test.a)
  1154  		if !v.IsValid() {
  1155  			continue
  1156  		}
  1157  		typ := TypeOf(test.a)
  1158  		if typ != v.Type() {
  1159  			t.Errorf("TypeOf(%v) = %v, but ValueOf(%v).Type() = %v", test.a, typ, test.a, v.Type())
  1160  		}
  1161  	}
  1162  }
  1163  
  1164  type Recursive struct {
  1165  	x int
  1166  	r *Recursive
  1167  }
  1168  
  1169  func TestDeepEqualRecursiveStruct(t *testing.T) {
  1170  	a, b := new(Recursive), new(Recursive)
  1171  	*a = Recursive{12, a}
  1172  	*b = Recursive{12, b}
  1173  	if !DeepEqual(a, b) {
  1174  		t.Error("DeepEqual(recursive same) = false, want true")
  1175  	}
  1176  }
  1177  
  1178  type _Complex struct {
  1179  	a int
  1180  	b [3]*_Complex
  1181  	c *string
  1182  	d map[float64]float64
  1183  }
  1184  
  1185  func TestDeepEqualComplexStruct(t *testing.T) {
  1186  	m := make(map[float64]float64)
  1187  	stra, strb := "hello", "hello"
  1188  	a, b := new(_Complex), new(_Complex)
  1189  	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
  1190  	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
  1191  	if !DeepEqual(a, b) {
  1192  		t.Error("DeepEqual(complex same) = false, want true")
  1193  	}
  1194  }
  1195  
  1196  func TestDeepEqualComplexStructInequality(t *testing.T) {
  1197  	m := make(map[float64]float64)
  1198  	stra, strb := "hello", "helloo" // Difference is here
  1199  	a, b := new(_Complex), new(_Complex)
  1200  	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
  1201  	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
  1202  	if DeepEqual(a, b) {
  1203  		t.Error("DeepEqual(complex different) = true, want false")
  1204  	}
  1205  }
  1206  
  1207  type UnexpT struct {
  1208  	m map[int]int
  1209  }
  1210  
  1211  func TestDeepEqualUnexportedMap(t *testing.T) {
  1212  	// Check that DeepEqual can look at unexported fields.
  1213  	x1 := UnexpT{map[int]int{1: 2}}
  1214  	x2 := UnexpT{map[int]int{1: 2}}
  1215  	if !DeepEqual(&x1, &x2) {
  1216  		t.Error("DeepEqual(x1, x2) = false, want true")
  1217  	}
  1218  
  1219  	y1 := UnexpT{map[int]int{2: 3}}
  1220  	if DeepEqual(&x1, &y1) {
  1221  		t.Error("DeepEqual(x1, y1) = true, want false")
  1222  	}
  1223  }
  1224  
  1225  var deepEqualPerfTests = []struct {
  1226  	x, y any
  1227  }{
  1228  	{x: int8(99), y: int8(99)},
  1229  	{x: []int8{99}, y: []int8{99}},
  1230  	{x: int16(99), y: int16(99)},
  1231  	{x: []int16{99}, y: []int16{99}},
  1232  	{x: int32(99), y: int32(99)},
  1233  	{x: []int32{99}, y: []int32{99}},
  1234  	{x: int64(99), y: int64(99)},
  1235  	{x: []int64{99}, y: []int64{99}},
  1236  	{x: int(999999), y: int(999999)},
  1237  	{x: []int{999999}, y: []int{999999}},
  1238  
  1239  	{x: uint8(99), y: uint8(99)},
  1240  	{x: []uint8{99}, y: []uint8{99}},
  1241  	{x: uint16(99), y: uint16(99)},
  1242  	{x: []uint16{99}, y: []uint16{99}},
  1243  	{x: uint32(99), y: uint32(99)},
  1244  	{x: []uint32{99}, y: []uint32{99}},
  1245  	{x: uint64(99), y: uint64(99)},
  1246  	{x: []uint64{99}, y: []uint64{99}},
  1247  	{x: uint(999999), y: uint(999999)},
  1248  	{x: []uint{999999}, y: []uint{999999}},
  1249  	{x: uintptr(999999), y: uintptr(999999)},
  1250  	{x: []uintptr{999999}, y: []uintptr{999999}},
  1251  
  1252  	{x: float32(1.414), y: float32(1.414)},
  1253  	{x: []float32{1.414}, y: []float32{1.414}},
  1254  	{x: float64(1.414), y: float64(1.414)},
  1255  	{x: []float64{1.414}, y: []float64{1.414}},
  1256  
  1257  	{x: complex64(1.414), y: complex64(1.414)},
  1258  	{x: []complex64{1.414}, y: []complex64{1.414}},
  1259  	{x: complex128(1.414), y: complex128(1.414)},
  1260  	{x: []complex128{1.414}, y: []complex128{1.414}},
  1261  
  1262  	{x: true, y: true},
  1263  	{x: []bool{true}, y: []bool{true}},
  1264  
  1265  	{x: "abcdef", y: "abcdef"},
  1266  	{x: []string{"abcdef"}, y: []string{"abcdef"}},
  1267  
  1268  	{x: []byte("abcdef"), y: []byte("abcdef")},
  1269  	{x: [][]byte{[]byte("abcdef")}, y: [][]byte{[]byte("abcdef")}},
  1270  
  1271  	{x: [6]byte{'a', 'b', 'c', 'a', 'b', 'c'}, y: [6]byte{'a', 'b', 'c', 'a', 'b', 'c'}},
  1272  	{x: [][6]byte{[6]byte{'a', 'b', 'c', 'a', 'b', 'c'}}, y: [][6]byte{[6]byte{'a', 'b', 'c', 'a', 'b', 'c'}}},
  1273  }
  1274  
  1275  func TestDeepEqualAllocs(t *testing.T) {
  1276  	for _, tt := range deepEqualPerfTests {
  1277  		t.Run(ValueOf(tt.x).Type().String(), func(t *testing.T) {
  1278  			got := testing.AllocsPerRun(100, func() {
  1279  				if !DeepEqual(tt.x, tt.y) {
  1280  					t.Errorf("DeepEqual(%v, %v)=false", tt.x, tt.y)
  1281  				}
  1282  			})
  1283  			if int(got) != 0 {
  1284  				t.Errorf("DeepEqual(%v, %v) allocated %d times", tt.x, tt.y, int(got))
  1285  			}
  1286  		})
  1287  	}
  1288  }
  1289  
  1290  func check2ndField(x any, offs uintptr, t *testing.T) {
  1291  	s := ValueOf(x)
  1292  	f := s.Type().Field(1)
  1293  	if f.Offset != offs {
  1294  		t.Error("mismatched offsets in structure alignment:", f.Offset, offs)
  1295  	}
  1296  }
  1297  
  1298  // Check that structure alignment & offsets viewed through reflect agree with those
  1299  // from the compiler itself.
  1300  func TestAlignment(t *testing.T) {
  1301  	type T1inner struct {
  1302  		a int
  1303  	}
  1304  	type T1 struct {
  1305  		T1inner
  1306  		f int
  1307  	}
  1308  	type T2inner struct {
  1309  		a, b int
  1310  	}
  1311  	type T2 struct {
  1312  		T2inner
  1313  		f int
  1314  	}
  1315  
  1316  	x := T1{T1inner{2}, 17}
  1317  	check2ndField(x, uintptr(unsafe.Pointer(&x.f))-uintptr(unsafe.Pointer(&x)), t)
  1318  
  1319  	x1 := T2{T2inner{2, 3}, 17}
  1320  	check2ndField(x1, uintptr(unsafe.Pointer(&x1.f))-uintptr(unsafe.Pointer(&x1)), t)
  1321  }
  1322  
  1323  func Nil(a any, t *testing.T) {
  1324  	n := ValueOf(a).Field(0)
  1325  	if !n.IsNil() {
  1326  		t.Errorf("%v should be nil", a)
  1327  	}
  1328  }
  1329  
  1330  func NotNil(a any, t *testing.T) {
  1331  	n := ValueOf(a).Field(0)
  1332  	if n.IsNil() {
  1333  		t.Errorf("value of type %v should not be nil", ValueOf(a).Type().String())
  1334  	}
  1335  }
  1336  
  1337  func TestIsNil(t *testing.T) {
  1338  	// These implement IsNil.
  1339  	// Wrap in extra struct to hide interface type.
  1340  	doNil := []any{
  1341  		struct{ x *int }{},
  1342  		struct{ x any }{},
  1343  		struct{ x map[string]int }{},
  1344  		struct{ x func() bool }{},
  1345  		struct{ x chan int }{},
  1346  		struct{ x []string }{},
  1347  		struct{ x unsafe.Pointer }{},
  1348  	}
  1349  	for _, ts := range doNil {
  1350  		ty := TypeOf(ts).Field(0).Type
  1351  		v := Zero(ty)
  1352  		v.IsNil() // panics if not okay to call
  1353  	}
  1354  
  1355  	// Check the implementations
  1356  	var pi struct {
  1357  		x *int
  1358  	}
  1359  	Nil(pi, t)
  1360  	pi.x = new(int)
  1361  	NotNil(pi, t)
  1362  
  1363  	var si struct {
  1364  		x []int
  1365  	}
  1366  	Nil(si, t)
  1367  	si.x = make([]int, 10)
  1368  	NotNil(si, t)
  1369  
  1370  	var ci struct {
  1371  		x chan int
  1372  	}
  1373  	Nil(ci, t)
  1374  	ci.x = make(chan int)
  1375  	NotNil(ci, t)
  1376  
  1377  	var mi struct {
  1378  		x map[int]int
  1379  	}
  1380  	Nil(mi, t)
  1381  	mi.x = make(map[int]int)
  1382  	NotNil(mi, t)
  1383  
  1384  	var ii struct {
  1385  		x any
  1386  	}
  1387  	Nil(ii, t)
  1388  	ii.x = 2
  1389  	NotNil(ii, t)
  1390  
  1391  	var fi struct {
  1392  		x func(t *testing.T)
  1393  	}
  1394  	Nil(fi, t)
  1395  	fi.x = TestIsNil
  1396  	NotNil(fi, t)
  1397  }
  1398  
  1399  func setField[S, V any](in S, offset uintptr, value V) (out S) {
  1400  	*(*V)(unsafe.Add(unsafe.Pointer(&in), offset)) = value
  1401  	return in
  1402  }
  1403  
  1404  func TestIsZero(t *testing.T) {
  1405  	for i, tt := range []struct {
  1406  		x    any
  1407  		want bool
  1408  	}{
  1409  		// Booleans
  1410  		{true, false},
  1411  		{false, true},
  1412  		// Numeric types
  1413  		{int(0), true},
  1414  		{int(1), false},
  1415  		{int8(0), true},
  1416  		{int8(1), false},
  1417  		{int16(0), true},
  1418  		{int16(1), false},
  1419  		{int32(0), true},
  1420  		{int32(1), false},
  1421  		{int64(0), true},
  1422  		{int64(1), false},
  1423  		{uint(0), true},
  1424  		{uint(1), false},
  1425  		{uint8(0), true},
  1426  		{uint8(1), false},
  1427  		{uint16(0), true},
  1428  		{uint16(1), false},
  1429  		{uint32(0), true},
  1430  		{uint32(1), false},
  1431  		{uint64(0), true},
  1432  		{uint64(1), false},
  1433  		{float32(0), true},
  1434  		{float32(1.2), false},
  1435  		{float64(0), true},
  1436  		{float64(1.2), false},
  1437  		{math.Copysign(0, -1), true},
  1438  		{complex64(0), true},
  1439  		{complex64(1.2), false},
  1440  		{complex128(0), true},
  1441  		{complex128(1.2), false},
  1442  		{complex(math.Copysign(0, -1), 0), true},
  1443  		{complex(0, math.Copysign(0, -1)), true},
  1444  		{complex(math.Copysign(0, -1), math.Copysign(0, -1)), true},
  1445  		{uintptr(0), true},
  1446  		{uintptr(128), false},
  1447  		// Array
  1448  		{Zero(TypeOf([5]string{})).Interface(), true},
  1449  		{[5]string{}, true},                     // comparable array
  1450  		{[5]string{"", "", "", "a", ""}, false}, // comparable array
  1451  		{[1]*int{}, true},                       // direct pointer array
  1452  		{[1]*int{new(int)}, false},              // direct pointer array
  1453  		{[3][]int{}, true},                      // incomparable array
  1454  		{[3][]int{{1}}, false},                  // incomparable array
  1455  		{[1 << 12]byte{}, true},
  1456  		{[1 << 12]byte{1}, false},
  1457  		{[1]struct{ p *int }{}, true},
  1458  		{[1]struct{ p *int }{{new(int)}}, false},
  1459  		{[3]Value{}, true},
  1460  		{[3]Value{{}, ValueOf(0), {}}, false},
  1461  		// Chan
  1462  		{(chan string)(nil), true},
  1463  		{make(chan string), false},
  1464  		{time.After(1), false},
  1465  		// Func
  1466  		{(func())(nil), true},
  1467  		{New, false},
  1468  		// Interface
  1469  		{New(TypeOf(new(error)).Elem()).Elem(), true},
  1470  		{(io.Reader)(strings.NewReader("")), false},
  1471  		// Map
  1472  		{(map[string]string)(nil), true},
  1473  		{map[string]string{}, false},
  1474  		{make(map[string]string), false},
  1475  		// Pointer
  1476  		{(*func())(nil), true},
  1477  		{(*int)(nil), true},
  1478  		{new(int), false},
  1479  		// Slice
  1480  		{[]string{}, false},
  1481  		{([]string)(nil), true},
  1482  		{make([]string, 0), false},
  1483  		// Strings
  1484  		{"", true},
  1485  		{"not-zero", false},
  1486  		// Structs
  1487  		{T{}, true},                           // comparable struct
  1488  		{T{123, 456.75, "hello", &_i}, false}, // comparable struct
  1489  		{struct{ p *int }{}, true},            // direct pointer struct
  1490  		{struct{ p *int }{new(int)}, false},   // direct pointer struct
  1491  		{struct{ s []int }{}, true},           // incomparable struct
  1492  		{struct{ s []int }{[]int{1}}, false},  // incomparable struct
  1493  		{struct{ Value }{}, true},
  1494  		{struct{ Value }{ValueOf(0)}, false},
  1495  		{struct{ _, a, _ uintptr }{}, true}, // comparable struct with blank fields
  1496  		{setField(struct{ _, a, _ uintptr }{}, 0*unsafe.Sizeof(uintptr(0)), 1), true},
  1497  		{setField(struct{ _, a, _ uintptr }{}, 1*unsafe.Sizeof(uintptr(0)), 1), false},
  1498  		{setField(struct{ _, a, _ uintptr }{}, 2*unsafe.Sizeof(uintptr(0)), 1), true},
  1499  		{struct{ _, a, _ func() }{}, true}, // incomparable struct with blank fields
  1500  		{setField(struct{ _, a, _ func() }{}, 0*unsafe.Sizeof((func())(nil)), func() {}), true},
  1501  		{setField(struct{ _, a, _ func() }{}, 1*unsafe.Sizeof((func())(nil)), func() {}), false},
  1502  		{setField(struct{ _, a, _ func() }{}, 2*unsafe.Sizeof((func())(nil)), func() {}), true},
  1503  		{struct{ a [256]S }{}, true},
  1504  		{struct{ a [256]S }{a: [256]S{2: {i1: 1}}}, false},
  1505  		{struct{ a [256]float32 }{}, true},
  1506  		{struct{ a [256]float32 }{a: [256]float32{2: 1.0}}, false},
  1507  		{struct{ _, a [256]S }{}, true},
  1508  		{setField(struct{ _, a [256]S }{}, 0*unsafe.Sizeof(int64(0)), int64(1)), true},
  1509  		// UnsafePointer
  1510  		{(unsafe.Pointer)(nil), true},
  1511  		{(unsafe.Pointer)(new(int)), false},
  1512  	} {
  1513  		var x Value
  1514  		if v, ok := tt.x.(Value); ok {
  1515  			x = v
  1516  		} else {
  1517  			x = ValueOf(tt.x)
  1518  		}
  1519  
  1520  		b := x.IsZero()
  1521  		if b != tt.want {
  1522  			t.Errorf("%d: IsZero((%s)(%+v)) = %t, want %t", i, x.Kind(), tt.x, b, tt.want)
  1523  		}
  1524  
  1525  		if !Zero(TypeOf(tt.x)).IsZero() {
  1526  			t.Errorf("%d: IsZero(Zero(TypeOf((%s)(%+v)))) is false", i, x.Kind(), tt.x)
  1527  		}
  1528  
  1529  		p := New(x.Type()).Elem()
  1530  		p.Set(x)
  1531  		p.SetZero()
  1532  		if !p.IsZero() {
  1533  			t.Errorf("%d: IsZero((%s)(%+v)) is true after SetZero", i, p.Kind(), tt.x)
  1534  		}
  1535  	}
  1536  
  1537  	func() {
  1538  		defer func() {
  1539  			if r := recover(); r == nil {
  1540  				t.Error("should panic for invalid value")
  1541  			}
  1542  		}()
  1543  		(Value{}).IsZero()
  1544  	}()
  1545  }
  1546  
  1547  func TestInternalIsZero(t *testing.T) {
  1548  	b := make([]byte, 512)
  1549  	for a := 0; a < 8; a++ {
  1550  		for i := 1; i <= 512-a; i++ {
  1551  			InternalIsZero(b[a : a+i])
  1552  		}
  1553  	}
  1554  }
  1555  
  1556  func TestInterfaceExtraction(t *testing.T) {
  1557  	var s struct {
  1558  		W io.Writer
  1559  	}
  1560  
  1561  	s.W = os.Stdout
  1562  	v := Indirect(ValueOf(&s)).Field(0).Interface()
  1563  	if v != s.W.(any) {
  1564  		t.Error("Interface() on interface: ", v, s.W)
  1565  	}
  1566  }
  1567  
  1568  func TestNilPtrValueSub(t *testing.T) {
  1569  	var pi *int
  1570  	if pv := ValueOf(pi); pv.Elem().IsValid() {
  1571  		t.Error("ValueOf((*int)(nil)).Elem().IsValid()")
  1572  	}
  1573  }
  1574  
  1575  func TestMap(t *testing.T) {
  1576  	m := map[string]int{"a": 1, "b": 2}
  1577  	mv := ValueOf(m)
  1578  	if n := mv.Len(); n != len(m) {
  1579  		t.Errorf("Len = %d, want %d", n, len(m))
  1580  	}
  1581  	keys := mv.MapKeys()
  1582  	newmap := MakeMap(mv.Type())
  1583  	for k, v := range m {
  1584  		// Check that returned Keys match keys in range.
  1585  		// These aren't required to be in the same order.
  1586  		seen := false
  1587  		for _, kv := range keys {
  1588  			if kv.String() == k {
  1589  				seen = true
  1590  				break
  1591  			}
  1592  		}
  1593  		if !seen {
  1594  			t.Errorf("Missing key %q", k)
  1595  		}
  1596  
  1597  		// Check that value lookup is correct.
  1598  		vv := mv.MapIndex(ValueOf(k))
  1599  		if vi := vv.Int(); vi != int64(v) {
  1600  			t.Errorf("Key %q: have value %d, want %d", k, vi, v)
  1601  		}
  1602  
  1603  		// Copy into new map.
  1604  		newmap.SetMapIndex(ValueOf(k), ValueOf(v))
  1605  	}
  1606  	vv := mv.MapIndex(ValueOf("not-present"))
  1607  	if vv.IsValid() {
  1608  		t.Errorf("Invalid key: got non-nil value %s", valueToString(vv))
  1609  	}
  1610  
  1611  	newm := newmap.Interface().(map[string]int)
  1612  	if len(newm) != len(m) {
  1613  		t.Errorf("length after copy: newm=%d, m=%d", len(newm), len(m))
  1614  	}
  1615  
  1616  	for k, v := range newm {
  1617  		mv, ok := m[k]
  1618  		if mv != v {
  1619  			t.Errorf("newm[%q] = %d, but m[%q] = %d, %v", k, v, k, mv, ok)
  1620  		}
  1621  	}
  1622  
  1623  	newmap.SetMapIndex(ValueOf("a"), Value{})
  1624  	v, ok := newm["a"]
  1625  	if ok {
  1626  		t.Errorf("newm[\"a\"] = %d after delete", v)
  1627  	}
  1628  
  1629  	mv = ValueOf(&m).Elem()
  1630  	mv.Set(Zero(mv.Type()))
  1631  	if m != nil {
  1632  		t.Errorf("mv.Set(nil) failed")
  1633  	}
  1634  
  1635  	type S string
  1636  	shouldPanic("not assignable", func() { mv.MapIndex(ValueOf(S("key"))) })
  1637  	shouldPanic("not assignable", func() { mv.SetMapIndex(ValueOf(S("key")), ValueOf(0)) })
  1638  }
  1639  
  1640  func TestNilMap(t *testing.T) {
  1641  	var m map[string]int
  1642  	mv := ValueOf(m)
  1643  	keys := mv.MapKeys()
  1644  	if len(keys) != 0 {
  1645  		t.Errorf(">0 keys for nil map: %v", keys)
  1646  	}
  1647  
  1648  	// Check that value for missing key is zero.
  1649  	x := mv.MapIndex(ValueOf("hello"))
  1650  	if x.Kind() != Invalid {
  1651  		t.Errorf("m.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
  1652  	}
  1653  
  1654  	// Check big value too.
  1655  	var mbig map[string][10 << 20]byte
  1656  	x = ValueOf(mbig).MapIndex(ValueOf("hello"))
  1657  	if x.Kind() != Invalid {
  1658  		t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
  1659  	}
  1660  
  1661  	// Test that deletes from a nil map succeed.
  1662  	mv.SetMapIndex(ValueOf("hi"), Value{})
  1663  }
  1664  
  1665  func TestChan(t *testing.T) {
  1666  	for loop := 0; loop < 2; loop++ {
  1667  		var c chan int
  1668  		var cv Value
  1669  
  1670  		// check both ways to allocate channels
  1671  		switch loop {
  1672  		case 1:
  1673  			c = make(chan int, 1)
  1674  			cv = ValueOf(c)
  1675  		case 0:
  1676  			cv = MakeChan(TypeOf(c), 1)
  1677  			c = cv.Interface().(chan int)
  1678  		}
  1679  
  1680  		// Send
  1681  		cv.Send(ValueOf(2))
  1682  		if i := <-c; i != 2 {
  1683  			t.Errorf("reflect Send 2, native recv %d", i)
  1684  		}
  1685  
  1686  		// Recv
  1687  		c <- 3
  1688  		if i, ok := cv.Recv(); i.Int() != 3 || !ok {
  1689  			t.Errorf("native send 3, reflect Recv %d, %t", i.Int(), ok)
  1690  		}
  1691  
  1692  		// TryRecv fail
  1693  		val, ok := cv.TryRecv()
  1694  		if val.IsValid() || ok {
  1695  			t.Errorf("TryRecv on empty chan: %s, %t", valueToString(val), ok)
  1696  		}
  1697  
  1698  		// TryRecv success
  1699  		c <- 4
  1700  		val, ok = cv.TryRecv()
  1701  		if !val.IsValid() {
  1702  			t.Errorf("TryRecv on ready chan got nil")
  1703  		} else if i := val.Int(); i != 4 || !ok {
  1704  			t.Errorf("native send 4, TryRecv %d, %t", i, ok)
  1705  		}
  1706  
  1707  		// TrySend fail
  1708  		c <- 100
  1709  		ok = cv.TrySend(ValueOf(5))
  1710  		i := <-c
  1711  		if ok {
  1712  			t.Errorf("TrySend on full chan succeeded: value %d", i)
  1713  		}
  1714  
  1715  		// TrySend success
  1716  		ok = cv.TrySend(ValueOf(6))
  1717  		if !ok {
  1718  			t.Errorf("TrySend on empty chan failed")
  1719  			select {
  1720  			case x := <-c:
  1721  				t.Errorf("TrySend failed but it did send %d", x)
  1722  			default:
  1723  			}
  1724  		} else {
  1725  			if i = <-c; i != 6 {
  1726  				t.Errorf("TrySend 6, recv %d", i)
  1727  			}
  1728  		}
  1729  
  1730  		// Close
  1731  		c <- 123
  1732  		cv.Close()
  1733  		if i, ok := cv.Recv(); i.Int() != 123 || !ok {
  1734  			t.Errorf("send 123 then close; Recv %d, %t", i.Int(), ok)
  1735  		}
  1736  		if i, ok := cv.Recv(); i.Int() != 0 || ok {
  1737  			t.Errorf("after close Recv %d, %t", i.Int(), ok)
  1738  		}
  1739  		// Closing a read-only channel
  1740  		shouldPanic("", func() {
  1741  			c := make(<-chan int, 1)
  1742  			cv := ValueOf(c)
  1743  			cv.Close()
  1744  		})
  1745  	}
  1746  
  1747  	// check creation of unbuffered channel
  1748  	var c chan int
  1749  	cv := MakeChan(TypeOf(c), 0)
  1750  	c = cv.Interface().(chan int)
  1751  	if cv.TrySend(ValueOf(7)) {
  1752  		t.Errorf("TrySend on sync chan succeeded")
  1753  	}
  1754  	if v, ok := cv.TryRecv(); v.IsValid() || ok {
  1755  		t.Errorf("TryRecv on sync chan succeeded: isvalid=%v ok=%v", v.IsValid(), ok)
  1756  	}
  1757  
  1758  	// len/cap
  1759  	cv = MakeChan(TypeOf(c), 10)
  1760  	c = cv.Interface().(chan int)
  1761  	for i := 0; i < 3; i++ {
  1762  		c <- i
  1763  	}
  1764  	if l, m := cv.Len(), cv.Cap(); l != len(c) || m != cap(c) {
  1765  		t.Errorf("Len/Cap = %d/%d want %d/%d", l, m, len(c), cap(c))
  1766  	}
  1767  }
  1768  
  1769  // caseInfo describes a single case in a select test.
  1770  type caseInfo struct {
  1771  	desc      string
  1772  	canSelect bool
  1773  	recv      Value
  1774  	closed    bool
  1775  	helper    func()
  1776  	panic     bool
  1777  }
  1778  
  1779  var allselect = flag.Bool("allselect", false, "exhaustive select test")
  1780  
  1781  func TestSelect(t *testing.T) {
  1782  	selectWatch.once.Do(func() { go selectWatcher() })
  1783  
  1784  	var x exhaustive
  1785  	nch := 0
  1786  	newop := func(n int, cap int) (ch, val Value) {
  1787  		nch++
  1788  		if nch%101%2 == 1 {
  1789  			c := make(chan int, cap)
  1790  			ch = ValueOf(c)
  1791  			val = ValueOf(n)
  1792  		} else {
  1793  			c := make(chan string, cap)
  1794  			ch = ValueOf(c)
  1795  			val = ValueOf(fmt.Sprint(n))
  1796  		}
  1797  		return
  1798  	}
  1799  
  1800  	for n := 0; x.Next(); n++ {
  1801  		if testing.Short() && n >= 1000 {
  1802  			break
  1803  		}
  1804  		if n >= 100000 && !*allselect {
  1805  			break
  1806  		}
  1807  		if n%100000 == 0 && testing.Verbose() {
  1808  			println("TestSelect", n)
  1809  		}
  1810  		var cases []SelectCase
  1811  		var info []caseInfo
  1812  
  1813  		// Ready send.
  1814  		if x.Maybe() {
  1815  			ch, val := newop(len(cases), 1)
  1816  			cases = append(cases, SelectCase{
  1817  				Dir:  SelectSend,
  1818  				Chan: ch,
  1819  				Send: val,
  1820  			})
  1821  			info = append(info, caseInfo{desc: "ready send", canSelect: true})
  1822  		}
  1823  
  1824  		// Ready recv.
  1825  		if x.Maybe() {
  1826  			ch, val := newop(len(cases), 1)
  1827  			ch.Send(val)
  1828  			cases = append(cases, SelectCase{
  1829  				Dir:  SelectRecv,
  1830  				Chan: ch,
  1831  			})
  1832  			info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val})
  1833  		}
  1834  
  1835  		// Blocking send.
  1836  		if x.Maybe() {
  1837  			ch, val := newop(len(cases), 0)
  1838  			cases = append(cases, SelectCase{
  1839  				Dir:  SelectSend,
  1840  				Chan: ch,
  1841  				Send: val,
  1842  			})
  1843  			// Let it execute?
  1844  			if x.Maybe() {
  1845  				f := func() { ch.Recv() }
  1846  				info = append(info, caseInfo{desc: "blocking send", helper: f})
  1847  			} else {
  1848  				info = append(info, caseInfo{desc: "blocking send"})
  1849  			}
  1850  		}
  1851  
  1852  		// Blocking recv.
  1853  		if x.Maybe() {
  1854  			ch, val := newop(len(cases), 0)
  1855  			cases = append(cases, SelectCase{
  1856  				Dir:  SelectRecv,
  1857  				Chan: ch,
  1858  			})
  1859  			// Let it execute?
  1860  			if x.Maybe() {
  1861  				f := func() { ch.Send(val) }
  1862  				info = append(info, caseInfo{desc: "blocking recv", recv: val, helper: f})
  1863  			} else {
  1864  				info = append(info, caseInfo{desc: "blocking recv"})
  1865  			}
  1866  		}
  1867  
  1868  		// Zero Chan send.
  1869  		if x.Maybe() {
  1870  			// Maybe include value to send.
  1871  			var val Value
  1872  			if x.Maybe() {
  1873  				val = ValueOf(100)
  1874  			}
  1875  			cases = append(cases, SelectCase{
  1876  				Dir:  SelectSend,
  1877  				Send: val,
  1878  			})
  1879  			info = append(info, caseInfo{desc: "zero Chan send"})
  1880  		}
  1881  
  1882  		// Zero Chan receive.
  1883  		if x.Maybe() {
  1884  			cases = append(cases, SelectCase{
  1885  				Dir: SelectRecv,
  1886  			})
  1887  			info = append(info, caseInfo{desc: "zero Chan recv"})
  1888  		}
  1889  
  1890  		// nil Chan send.
  1891  		if x.Maybe() {
  1892  			cases = append(cases, SelectCase{
  1893  				Dir:  SelectSend,
  1894  				Chan: ValueOf((chan int)(nil)),
  1895  				Send: ValueOf(101),
  1896  			})
  1897  			info = append(info, caseInfo{desc: "nil Chan send"})
  1898  		}
  1899  
  1900  		// nil Chan recv.
  1901  		if x.Maybe() {
  1902  			cases = append(cases, SelectCase{
  1903  				Dir:  SelectRecv,
  1904  				Chan: ValueOf((chan int)(nil)),
  1905  			})
  1906  			info = append(info, caseInfo{desc: "nil Chan recv"})
  1907  		}
  1908  
  1909  		// closed Chan send.
  1910  		if x.Maybe() {
  1911  			ch := make(chan int)
  1912  			close(ch)
  1913  			cases = append(cases, SelectCase{
  1914  				Dir:  SelectSend,
  1915  				Chan: ValueOf(ch),
  1916  				Send: ValueOf(101),
  1917  			})
  1918  			info = append(info, caseInfo{desc: "closed Chan send", canSelect: true, panic: true})
  1919  		}
  1920  
  1921  		// closed Chan recv.
  1922  		if x.Maybe() {
  1923  			ch, val := newop(len(cases), 0)
  1924  			ch.Close()
  1925  			val = Zero(val.Type())
  1926  			cases = append(cases, SelectCase{
  1927  				Dir:  SelectRecv,
  1928  				Chan: ch,
  1929  			})
  1930  			info = append(info, caseInfo{desc: "closed Chan recv", canSelect: true, closed: true, recv: val})
  1931  		}
  1932  
  1933  		var helper func() // goroutine to help the select complete
  1934  
  1935  		// Add default? Must be last case here, but will permute.
  1936  		// Add the default if the select would otherwise
  1937  		// block forever, and maybe add it anyway.
  1938  		numCanSelect := 0
  1939  		canProceed := false
  1940  		canBlock := true
  1941  		canPanic := false
  1942  		helpers := []int{}
  1943  		for i, c := range info {
  1944  			if c.canSelect {
  1945  				canProceed = true
  1946  				canBlock = false
  1947  				numCanSelect++
  1948  				if c.panic {
  1949  					canPanic = true
  1950  				}
  1951  			} else if c.helper != nil {
  1952  				canProceed = true
  1953  				helpers = append(helpers, i)
  1954  			}
  1955  		}
  1956  		if !canProceed || x.Maybe() {
  1957  			cases = append(cases, SelectCase{
  1958  				Dir: SelectDefault,
  1959  			})
  1960  			info = append(info, caseInfo{desc: "default", canSelect: canBlock})
  1961  			numCanSelect++
  1962  		} else if canBlock {
  1963  			// Select needs to communicate with another goroutine.
  1964  			cas := &info[helpers[x.Choose(len(helpers))]]
  1965  			helper = cas.helper
  1966  			cas.canSelect = true
  1967  			numCanSelect++
  1968  		}
  1969  
  1970  		// Permute cases and case info.
  1971  		// Doing too much here makes the exhaustive loop
  1972  		// too exhausting, so just do two swaps.
  1973  		for loop := 0; loop < 2; loop++ {
  1974  			i := x.Choose(len(cases))
  1975  			j := x.Choose(len(cases))
  1976  			cases[i], cases[j] = cases[j], cases[i]
  1977  			info[i], info[j] = info[j], info[i]
  1978  		}
  1979  
  1980  		if helper != nil {
  1981  			// We wait before kicking off a goroutine to satisfy a blocked select.
  1982  			// The pause needs to be big enough to let the select block before
  1983  			// we run the helper, but if we lose that race once in a while it's okay: the
  1984  			// select will just proceed immediately. Not a big deal.
  1985  			// For short tests we can grow [sic] the timeout a bit without fear of taking too long
  1986  			pause := 10 * time.Microsecond
  1987  			if testing.Short() {
  1988  				pause = 100 * time.Microsecond
  1989  			}
  1990  			time.AfterFunc(pause, helper)
  1991  		}
  1992  
  1993  		// Run select.
  1994  		i, recv, recvOK, panicErr := runSelect(cases, info)
  1995  		if panicErr != nil && !canPanic {
  1996  			t.Fatalf("%s\npanicked unexpectedly: %v", fmtSelect(info), panicErr)
  1997  		}
  1998  		if panicErr == nil && canPanic && numCanSelect == 1 {
  1999  			t.Fatalf("%s\nselected #%d incorrectly (should panic)", fmtSelect(info), i)
  2000  		}
  2001  		if panicErr != nil {
  2002  			continue
  2003  		}
  2004  
  2005  		cas := info[i]
  2006  		if !cas.canSelect {
  2007  			recvStr := ""
  2008  			if recv.IsValid() {
  2009  				recvStr = fmt.Sprintf(", received %v, %v", recv.Interface(), recvOK)
  2010  			}
  2011  			t.Fatalf("%s\nselected #%d incorrectly%s", fmtSelect(info), i, recvStr)
  2012  		}
  2013  		if cas.panic {
  2014  			t.Fatalf("%s\nselected #%d incorrectly (case should panic)", fmtSelect(info), i)
  2015  		}
  2016  
  2017  		if cases[i].Dir == SelectRecv {
  2018  			if !recv.IsValid() {
  2019  				t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, cas.recv.Interface(), !cas.closed)
  2020  			}
  2021  			if !cas.recv.IsValid() {
  2022  				t.Fatalf("%s\nselected #%d but internal error: missing recv value", fmtSelect(info), i)
  2023  			}
  2024  			if recv.Interface() != cas.recv.Interface() || recvOK != !cas.closed {
  2025  				if recv.Interface() == cas.recv.Interface() && recvOK == !cas.closed {
  2026  					t.Fatalf("%s\nselected #%d, got %#v, %v, and DeepEqual is broken on %T", fmtSelect(info), i, recv.Interface(), recvOK, recv.Interface())
  2027  				}
  2028  				t.Fatalf("%s\nselected #%d but got %#v, %v, want %#v, %v", fmtSelect(info), i, recv.Interface(), recvOK, cas.recv.Interface(), !cas.closed)
  2029  			}
  2030  		} else {
  2031  			if recv.IsValid() || recvOK {
  2032  				t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, Value{}, false)
  2033  			}
  2034  		}
  2035  	}
  2036  }
  2037  
  2038  func TestSelectMaxCases(t *testing.T) {
  2039  	var sCases []SelectCase
  2040  	channel := make(chan int)
  2041  	close(channel)
  2042  	for i := 0; i < 65536; i++ {
  2043  		sCases = append(sCases, SelectCase{
  2044  			Dir:  SelectRecv,
  2045  			Chan: ValueOf(channel),
  2046  		})
  2047  	}
  2048  	// Should not panic
  2049  	_, _, _ = Select(sCases)
  2050  	sCases = append(sCases, SelectCase{
  2051  		Dir:  SelectRecv,
  2052  		Chan: ValueOf(channel),
  2053  	})
  2054  	defer func() {
  2055  		if err := recover(); err != nil {
  2056  			if err.(string) != "reflect.Select: too many cases (max 65536)" {
  2057  				t.Fatalf("unexpected error from select call with greater than max supported cases")
  2058  			}
  2059  		} else {
  2060  			t.Fatalf("expected select call to panic with greater than max supported cases")
  2061  		}
  2062  	}()
  2063  	// Should panic
  2064  	_, _, _ = Select(sCases)
  2065  }
  2066  
  2067  func TestSelectNop(t *testing.T) {
  2068  	// "select { default: }" should always return the default case.
  2069  	chosen, _, _ := Select([]SelectCase{{Dir: SelectDefault}})
  2070  	if chosen != 0 {
  2071  		t.Fatalf("expected Select to return 0, but got %#v", chosen)
  2072  	}
  2073  }
  2074  
  2075  // selectWatch and the selectWatcher are a watchdog mechanism for running Select.
  2076  // If the selectWatcher notices that the select has been blocked for >1 second, it prints
  2077  // an error describing the select and panics the entire test binary.
  2078  var selectWatch struct {
  2079  	sync.Mutex
  2080  	once sync.Once
  2081  	now  time.Time
  2082  	info []caseInfo
  2083  }
  2084  
  2085  func selectWatcher() {
  2086  	for {
  2087  		time.Sleep(1 * time.Second)
  2088  		selectWatch.Lock()
  2089  		if selectWatch.info != nil && time.Since(selectWatch.now) > 10*time.Second {
  2090  			fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info))
  2091  			panic("select stuck")
  2092  		}
  2093  		selectWatch.Unlock()
  2094  	}
  2095  }
  2096  
  2097  // runSelect runs a single select test.
  2098  // It returns the values returned by Select but also returns
  2099  // a panic value if the Select panics.
  2100  func runSelect(cases []SelectCase, info []caseInfo) (chosen int, recv Value, recvOK bool, panicErr any) {
  2101  	defer func() {
  2102  		panicErr = recover()
  2103  
  2104  		selectWatch.Lock()
  2105  		selectWatch.info = nil
  2106  		selectWatch.Unlock()
  2107  	}()
  2108  
  2109  	selectWatch.Lock()
  2110  	selectWatch.now = time.Now()
  2111  	selectWatch.info = info
  2112  	selectWatch.Unlock()
  2113  
  2114  	chosen, recv, recvOK = Select(cases)
  2115  	return
  2116  }
  2117  
  2118  // fmtSelect formats the information about a single select test.
  2119  func fmtSelect(info []caseInfo) string {
  2120  	var buf strings.Builder
  2121  	fmt.Fprintf(&buf, "\nselect {\n")
  2122  	for i, cas := range info {
  2123  		fmt.Fprintf(&buf, "%d: %s", i, cas.desc)
  2124  		if cas.recv.IsValid() {
  2125  			fmt.Fprintf(&buf, " val=%#v", cas.recv.Interface())
  2126  		}
  2127  		if cas.canSelect {
  2128  			fmt.Fprintf(&buf, " canselect")
  2129  		}
  2130  		if cas.panic {
  2131  			fmt.Fprintf(&buf, " panic")
  2132  		}
  2133  		fmt.Fprintf(&buf, "\n")
  2134  	}
  2135  	fmt.Fprintf(&buf, "}")
  2136  	return buf.String()
  2137  }
  2138  
  2139  type two [2]uintptr
  2140  
  2141  // Difficult test for function call because of
  2142  // implicit padding between arguments.
  2143  func dummy(b byte, c int, d byte, e two, f byte, g float32, h byte) (i byte, j int, k byte, l two, m byte, n float32, o byte) {
  2144  	return b, c, d, e, f, g, h
  2145  }
  2146  
  2147  func TestFunc(t *testing.T) {
  2148  	ret := ValueOf(dummy).Call([]Value{
  2149  		ValueOf(byte(10)),
  2150  		ValueOf(20),
  2151  		ValueOf(byte(30)),
  2152  		ValueOf(two{40, 50}),
  2153  		ValueOf(byte(60)),
  2154  		ValueOf(float32(70)),
  2155  		ValueOf(byte(80)),
  2156  	})
  2157  	if len(ret) != 7 {
  2158  		t.Fatalf("Call returned %d values, want 7", len(ret))
  2159  	}
  2160  
  2161  	i := byte(ret[0].Uint())
  2162  	j := int(ret[1].Int())
  2163  	k := byte(ret[2].Uint())
  2164  	l := ret[3].Interface().(two)
  2165  	m := byte(ret[4].Uint())
  2166  	n := float32(ret[5].Float())
  2167  	o := byte(ret[6].Uint())
  2168  
  2169  	if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
  2170  		t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o)
  2171  	}
  2172  
  2173  	for i, v := range ret {
  2174  		if v.CanAddr() {
  2175  			t.Errorf("result %d is addressable", i)
  2176  		}
  2177  	}
  2178  }
  2179  
  2180  func TestCallConvert(t *testing.T) {
  2181  	v := ValueOf(new(io.ReadWriter)).Elem()
  2182  	f := ValueOf(func(r io.Reader) io.Reader { return r })
  2183  	out := f.Call([]Value{v})
  2184  	if len(out) != 1 || out[0].Type() != TypeOf(new(io.Reader)).Elem() || !out[0].IsNil() {
  2185  		t.Errorf("expected [nil], got %v", out)
  2186  	}
  2187  }
  2188  
  2189  type emptyStruct struct{}
  2190  
  2191  type nonEmptyStruct struct {
  2192  	member int
  2193  }
  2194  
  2195  func returnEmpty() emptyStruct {
  2196  	return emptyStruct{}
  2197  }
  2198  
  2199  func takesEmpty(e emptyStruct) {
  2200  }
  2201  
  2202  func returnNonEmpty(i int) nonEmptyStruct {
  2203  	return nonEmptyStruct{member: i}
  2204  }
  2205  
  2206  func takesNonEmpty(n nonEmptyStruct) int {
  2207  	return n.member
  2208  }
  2209  
  2210  func TestCallWithStruct(t *testing.T) {
  2211  	r := ValueOf(returnEmpty).Call(nil)
  2212  	if len(r) != 1 || r[0].Type() != TypeOf(emptyStruct{}) {
  2213  		t.Errorf("returning empty struct returned %#v instead", r)
  2214  	}
  2215  	r = ValueOf(takesEmpty).Call([]Value{ValueOf(emptyStruct{})})
  2216  	if len(r) != 0 {
  2217  		t.Errorf("takesEmpty returned values: %#v", r)
  2218  	}
  2219  	r = ValueOf(returnNonEmpty).Call([]Value{ValueOf(42)})
  2220  	if len(r) != 1 || r[0].Type() != TypeOf(nonEmptyStruct{}) || r[0].Field(0).Int() != 42 {
  2221  		t.Errorf("returnNonEmpty returned %#v", r)
  2222  	}
  2223  	r = ValueOf(takesNonEmpty).Call([]Value{ValueOf(nonEmptyStruct{member: 42})})
  2224  	if len(r) != 1 || r[0].Type() != TypeOf(1) || r[0].Int() != 42 {
  2225  		t.Errorf("takesNonEmpty returned %#v", r)
  2226  	}
  2227  }
  2228  
  2229  func TestCallReturnsEmpty(t *testing.T) {
  2230  	// Issue 21717: past-the-end pointer write in Call with
  2231  	// nonzero-sized frame and zero-sized return value.
  2232  	runtime.GC()
  2233  	var finalized uint32
  2234  	f := func() (emptyStruct, *[2]int64) {
  2235  		i := new([2]int64) // big enough to not be tinyalloc'd, so finalizer always runs when i dies
  2236  		runtime.SetFinalizer(i, func(*[2]int64) { atomic.StoreUint32(&finalized, 1) })
  2237  		return emptyStruct{}, i
  2238  	}
  2239  	v := ValueOf(f).Call(nil)[0] // out[0] should not alias out[1]'s memory, so the finalizer should run.
  2240  	timeout := time.After(5 * time.Second)
  2241  	for atomic.LoadUint32(&finalized) == 0 {
  2242  		select {
  2243  		case <-timeout:
  2244  			t.Fatal("finalizer did not run")
  2245  		default:
  2246  		}
  2247  		runtime.Gosched()
  2248  		runtime.GC()
  2249  	}
  2250  	runtime.KeepAlive(v)
  2251  }
  2252  
  2253  func TestMakeFunc(t *testing.T) {
  2254  	f := dummy
  2255  	fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in })
  2256  	ValueOf(&f).Elem().Set(fv)
  2257  
  2258  	// Call g with small arguments so that there is
  2259  	// something predictable (and different from the
  2260  	// correct results) in those positions on the stack.
  2261  	g := dummy
  2262  	g(1, 2, 3, two{4, 5}, 6, 7, 8)
  2263  
  2264  	// Call constructed function f.
  2265  	i, j, k, l, m, n, o := f(10, 20, 30, two{40, 50}, 60, 70, 80)
  2266  	if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
  2267  		t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o)
  2268  	}
  2269  }
  2270  
  2271  func TestMakeFuncInterface(t *testing.T) {
  2272  	fn := func(i int) int { return i }
  2273  	incr := func(in []Value) []Value {
  2274  		return []Value{ValueOf(int(in[0].Int() + 1))}
  2275  	}
  2276  	fv := MakeFunc(TypeOf(fn), incr)
  2277  	ValueOf(&fn).Elem().Set(fv)
  2278  	if r := fn(2); r != 3 {
  2279  		t.Errorf("Call returned %d, want 3", r)
  2280  	}
  2281  	if r := fv.Call([]Value{ValueOf(14)})[0].Int(); r != 15 {
  2282  		t.Errorf("Call returned %d, want 15", r)
  2283  	}
  2284  	if r := fv.Interface().(func(int) int)(26); r != 27 {
  2285  		t.Errorf("Call returned %d, want 27", r)
  2286  	}
  2287  }
  2288  
  2289  func TestMakeFuncVariadic(t *testing.T) {
  2290  	// Test that variadic arguments are packed into a slice and passed as last arg
  2291  	fn := func(_ int, is ...int) []int { return nil }
  2292  	fv := MakeFunc(TypeOf(fn), func(in []Value) []Value { return in[1:2] })
  2293  	ValueOf(&fn).Elem().Set(fv)
  2294  
  2295  	r := fn(1, 2, 3)
  2296  	if r[0] != 2 || r[1] != 3 {
  2297  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  2298  	}
  2299  
  2300  	r = fn(1, []int{2, 3}...)
  2301  	if r[0] != 2 || r[1] != 3 {
  2302  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  2303  	}
  2304  
  2305  	r = fv.Call([]Value{ValueOf(1), ValueOf(2), ValueOf(3)})[0].Interface().([]int)
  2306  	if r[0] != 2 || r[1] != 3 {
  2307  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  2308  	}
  2309  
  2310  	r = fv.CallSlice([]Value{ValueOf(1), ValueOf([]int{2, 3})})[0].Interface().([]int)
  2311  	if r[0] != 2 || r[1] != 3 {
  2312  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  2313  	}
  2314  
  2315  	f := fv.Interface().(func(int, ...int) []int)
  2316  
  2317  	r = f(1, 2, 3)
  2318  	if r[0] != 2 || r[1] != 3 {
  2319  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  2320  	}
  2321  	r = f(1, []int{2, 3}...)
  2322  	if r[0] != 2 || r[1] != 3 {
  2323  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  2324  	}
  2325  }
  2326  
  2327  // Dummy type that implements io.WriteCloser
  2328  type WC struct {
  2329  }
  2330  
  2331  func (w *WC) Write(p []byte) (n int, err error) {
  2332  	return 0, nil
  2333  }
  2334  func (w *WC) Close() error {
  2335  	return nil
  2336  }
  2337  
  2338  func TestMakeFuncValidReturnAssignments(t *testing.T) {
  2339  	// reflect.Values returned from the wrapped function should be assignment-converted
  2340  	// to the types returned by the result of MakeFunc.
  2341  
  2342  	// Concrete types should be promotable to interfaces they implement.
  2343  	var f func() error
  2344  	f = MakeFunc(TypeOf(f), func([]Value) []Value {
  2345  		return []Value{ValueOf(io.EOF)}
  2346  	}).Interface().(func() error)
  2347  	f()
  2348  
  2349  	// Super-interfaces should be promotable to simpler interfaces.
  2350  	var g func() io.Writer
  2351  	g = MakeFunc(TypeOf(g), func([]Value) []Value {
  2352  		var w io.WriteCloser = &WC{}
  2353  		return []Value{ValueOf(&w).Elem()}
  2354  	}).Interface().(func() io.Writer)
  2355  	g()
  2356  
  2357  	// Channels should be promotable to directional channels.
  2358  	var h func() <-chan int
  2359  	h = MakeFunc(TypeOf(h), func([]Value) []Value {
  2360  		return []Value{ValueOf(make(chan int))}
  2361  	}).Interface().(func() <-chan int)
  2362  	h()
  2363  
  2364  	// Unnamed types should be promotable to named types.
  2365  	type T struct{ a, b, c int }
  2366  	var i func() T
  2367  	i = MakeFunc(TypeOf(i), func([]Value) []Value {
  2368  		return []Value{ValueOf(struct{ a, b, c int }{a: 1, b: 2, c: 3})}
  2369  	}).Interface().(func() T)
  2370  	i()
  2371  }
  2372  
  2373  func TestMakeFuncInvalidReturnAssignments(t *testing.T) {
  2374  	// Type doesn't implement the required interface.
  2375  	shouldPanic("", func() {
  2376  		var f func() error
  2377  		f = MakeFunc(TypeOf(f), func([]Value) []Value {
  2378  			return []Value{ValueOf(int(7))}
  2379  		}).Interface().(func() error)
  2380  		f()
  2381  	})
  2382  	// Assigning to an interface with additional methods.
  2383  	shouldPanic("", func() {
  2384  		var f func() io.ReadWriteCloser
  2385  		f = MakeFunc(TypeOf(f), func([]Value) []Value {
  2386  			var w io.WriteCloser = &WC{}
  2387  			return []Value{ValueOf(&w).Elem()}
  2388  		}).Interface().(func() io.ReadWriteCloser)
  2389  		f()
  2390  	})
  2391  	// Directional channels can't be assigned to bidirectional ones.
  2392  	shouldPanic("", func() {
  2393  		var f func() chan int
  2394  		f = MakeFunc(TypeOf(f), func([]Value) []Value {
  2395  			var c <-chan int = make(chan int)
  2396  			return []Value{ValueOf(c)}
  2397  		}).Interface().(func() chan int)
  2398  		f()
  2399  	})
  2400  	// Two named types which are otherwise identical.
  2401  	shouldPanic("", func() {
  2402  		type T struct{ a, b, c int }
  2403  		type U struct{ a, b, c int }
  2404  		var f func() T
  2405  		f = MakeFunc(TypeOf(f), func([]Value) []Value {
  2406  			return []Value{ValueOf(U{a: 1, b: 2, c: 3})}
  2407  		}).Interface().(func() T)
  2408  		f()
  2409  	})
  2410  }
  2411  
  2412  type Point struct {
  2413  	x, y int
  2414  }
  2415  
  2416  // This will be index 0.
  2417  func (p Point) AnotherMethod(scale int) int {
  2418  	return -1
  2419  }
  2420  
  2421  // This will be index 1.
  2422  func (p Point) Dist(scale int) int {
  2423  	//println("Point.Dist", p.x, p.y, scale)
  2424  	return p.x*p.x*scale + p.y*p.y*scale
  2425  }
  2426  
  2427  // This will be index 2.
  2428  func (p Point) GCMethod(k int) int {
  2429  	runtime.GC()
  2430  	return k + p.x
  2431  }
  2432  
  2433  // This will be index 3.
  2434  func (p Point) NoArgs() {
  2435  	// Exercise no-argument/no-result paths.
  2436  }
  2437  
  2438  // This will be index 4.
  2439  func (p Point) TotalDist(points ...Point) int {
  2440  	tot := 0
  2441  	for _, q := range points {
  2442  		dx := q.x - p.x
  2443  		dy := q.y - p.y
  2444  		tot += dx*dx + dy*dy // Should call Sqrt, but it's just a test.
  2445  
  2446  	}
  2447  	return tot
  2448  }
  2449  
  2450  // This will be index 5.
  2451  func (p *Point) Int64Method(x int64) int64 {
  2452  	return x
  2453  }
  2454  
  2455  // This will be index 6.
  2456  func (p *Point) Int32Method(x int32) int32 {
  2457  	return x
  2458  }
  2459  
  2460  func TestMethod(t *testing.T) {
  2461  	// Non-curried method of type.
  2462  	p := Point{3, 4}
  2463  	i := TypeOf(p).Method(1).Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int()
  2464  	if i != 250 {
  2465  		t.Errorf("Type Method returned %d; want 250", i)
  2466  	}
  2467  
  2468  	m, ok := TypeOf(p).MethodByName("Dist")
  2469  	if !ok {
  2470  		t.Fatalf("method by name failed")
  2471  	}
  2472  	i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int()
  2473  	if i != 275 {
  2474  		t.Errorf("Type MethodByName returned %d; want 275", i)
  2475  	}
  2476  
  2477  	m, ok = TypeOf(p).MethodByName("NoArgs")
  2478  	if !ok {
  2479  		t.Fatalf("method by name failed")
  2480  	}
  2481  	n := len(m.Func.Call([]Value{ValueOf(p)}))
  2482  	if n != 0 {
  2483  		t.Errorf("NoArgs returned %d values; want 0", n)
  2484  	}
  2485  
  2486  	i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int()
  2487  	if i != 300 {
  2488  		t.Errorf("Pointer Type Method returned %d; want 300", i)
  2489  	}
  2490  
  2491  	m, ok = TypeOf(&p).MethodByName("Dist")
  2492  	if !ok {
  2493  		t.Fatalf("ptr method by name failed")
  2494  	}
  2495  	i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int()
  2496  	if i != 325 {
  2497  		t.Errorf("Pointer Type MethodByName returned %d; want 325", i)
  2498  	}
  2499  
  2500  	m, ok = TypeOf(&p).MethodByName("NoArgs")
  2501  	if !ok {
  2502  		t.Fatalf("method by name failed")
  2503  	}
  2504  	n = len(m.Func.Call([]Value{ValueOf(&p)}))
  2505  	if n != 0 {
  2506  		t.Errorf("NoArgs returned %d values; want 0", n)
  2507  	}
  2508  
  2509  	_, ok = TypeOf(&p).MethodByName("AA")
  2510  	if ok {
  2511  		t.Errorf(`MethodByName("AA") should have failed`)
  2512  	}
  2513  
  2514  	_, ok = TypeOf(&p).MethodByName("ZZ")
  2515  	if ok {
  2516  		t.Errorf(`MethodByName("ZZ") should have failed`)
  2517  	}
  2518  
  2519  	// Curried method of value.
  2520  	tfunc := TypeOf((func(int) int)(nil))
  2521  	v := ValueOf(p).Method(1)
  2522  	if tt := v.Type(); tt != tfunc {
  2523  		t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
  2524  	}
  2525  	i = v.Call([]Value{ValueOf(14)})[0].Int()
  2526  	if i != 350 {
  2527  		t.Errorf("Value Method returned %d; want 350", i)
  2528  	}
  2529  	v = ValueOf(p).MethodByName("Dist")
  2530  	if tt := v.Type(); tt != tfunc {
  2531  		t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
  2532  	}
  2533  	i = v.Call([]Value{ValueOf(15)})[0].Int()
  2534  	if i != 375 {
  2535  		t.Errorf("Value MethodByName returned %d; want 375", i)
  2536  	}
  2537  	v = ValueOf(p).MethodByName("NoArgs")
  2538  	v.Call(nil)
  2539  
  2540  	// Curried method of pointer.
  2541  	v = ValueOf(&p).Method(1)
  2542  	if tt := v.Type(); tt != tfunc {
  2543  		t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
  2544  	}
  2545  	i = v.Call([]Value{ValueOf(16)})[0].Int()
  2546  	if i != 400 {
  2547  		t.Errorf("Pointer Value Method returned %d; want 400", i)
  2548  	}
  2549  	v = ValueOf(&p).MethodByName("Dist")
  2550  	if tt := v.Type(); tt != tfunc {
  2551  		t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  2552  	}
  2553  	i = v.Call([]Value{ValueOf(17)})[0].Int()
  2554  	if i != 425 {
  2555  		t.Errorf("Pointer Value MethodByName returned %d; want 425", i)
  2556  	}
  2557  	v = ValueOf(&p).MethodByName("NoArgs")
  2558  	v.Call(nil)
  2559  
  2560  	// Curried method of interface value.
  2561  	// Have to wrap interface value in a struct to get at it.
  2562  	// Passing it to ValueOf directly would
  2563  	// access the underlying Point, not the interface.
  2564  	var x interface {
  2565  		Dist(int) int
  2566  	} = p
  2567  	pv := ValueOf(&x).Elem()
  2568  	v = pv.Method(0)
  2569  	if tt := v.Type(); tt != tfunc {
  2570  		t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
  2571  	}
  2572  	i = v.Call([]Value{ValueOf(18)})[0].Int()
  2573  	if i != 450 {
  2574  		t.Errorf("Interface Method returned %d; want 450", i)
  2575  	}
  2576  	v = pv.MethodByName("Dist")
  2577  	if tt := v.Type(); tt != tfunc {
  2578  		t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
  2579  	}
  2580  	i = v.Call([]Value{ValueOf(19)})[0].Int()
  2581  	if i != 475 {
  2582  		t.Errorf("Interface MethodByName returned %d; want 475", i)
  2583  	}
  2584  }
  2585  
  2586  func TestMethodValue(t *testing.T) {
  2587  	p := Point{3, 4}
  2588  	var i int64
  2589  
  2590  	// Check that method value have the same underlying code pointers.
  2591  	if p1, p2 := ValueOf(Point{1, 1}).Method(1), ValueOf(Point{2, 2}).Method(1); p1.Pointer() != p2.Pointer() {
  2592  		t.Errorf("methodValueCall mismatched: %v - %v", p1, p2)
  2593  	}
  2594  
  2595  	// Curried method of value.
  2596  	tfunc := TypeOf((func(int) int)(nil))
  2597  	v := ValueOf(p).Method(1)
  2598  	if tt := v.Type(); tt != tfunc {
  2599  		t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
  2600  	}
  2601  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int()
  2602  	if i != 250 {
  2603  		t.Errorf("Value Method returned %d; want 250", i)
  2604  	}
  2605  	v = ValueOf(p).MethodByName("Dist")
  2606  	if tt := v.Type(); tt != tfunc {
  2607  		t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
  2608  	}
  2609  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int()
  2610  	if i != 275 {
  2611  		t.Errorf("Value MethodByName returned %d; want 275", i)
  2612  	}
  2613  	v = ValueOf(p).MethodByName("NoArgs")
  2614  	ValueOf(v.Interface()).Call(nil)
  2615  	v.Interface().(func())()
  2616  
  2617  	// Curried method of pointer.
  2618  	v = ValueOf(&p).Method(1)
  2619  	if tt := v.Type(); tt != tfunc {
  2620  		t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
  2621  	}
  2622  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int()
  2623  	if i != 300 {
  2624  		t.Errorf("Pointer Value Method returned %d; want 300", i)
  2625  	}
  2626  	v = ValueOf(&p).MethodByName("Dist")
  2627  	if tt := v.Type(); tt != tfunc {
  2628  		t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  2629  	}
  2630  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int()
  2631  	if i != 325 {
  2632  		t.Errorf("Pointer Value MethodByName returned %d; want 325", i)
  2633  	}
  2634  	v = ValueOf(&p).MethodByName("NoArgs")
  2635  	ValueOf(v.Interface()).Call(nil)
  2636  	v.Interface().(func())()
  2637  
  2638  	// Curried method of pointer to pointer.
  2639  	pp := &p
  2640  	v = ValueOf(&pp).Elem().Method(1)
  2641  	if tt := v.Type(); tt != tfunc {
  2642  		t.Errorf("Pointer Pointer Value Method Type is %s; want %s", tt, tfunc)
  2643  	}
  2644  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int()
  2645  	if i != 350 {
  2646  		t.Errorf("Pointer Pointer Value Method returned %d; want 350", i)
  2647  	}
  2648  	v = ValueOf(&pp).Elem().MethodByName("Dist")
  2649  	if tt := v.Type(); tt != tfunc {
  2650  		t.Errorf("Pointer Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  2651  	}
  2652  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int()
  2653  	if i != 375 {
  2654  		t.Errorf("Pointer Pointer Value MethodByName returned %d; want 375", i)
  2655  	}
  2656  
  2657  	// Curried method of interface value.
  2658  	// Have to wrap interface value in a struct to get at it.
  2659  	// Passing it to ValueOf directly would
  2660  	// access the underlying Point, not the interface.
  2661  	var s = struct {
  2662  		X interface {
  2663  			Dist(int) int
  2664  		}
  2665  	}{p}
  2666  	pv := ValueOf(s).Field(0)
  2667  	v = pv.Method(0)
  2668  	if tt := v.Type(); tt != tfunc {
  2669  		t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
  2670  	}
  2671  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(16)})[0].Int()
  2672  	if i != 400 {
  2673  		t.Errorf("Interface Method returned %d; want 400", i)
  2674  	}
  2675  	v = pv.MethodByName("Dist")
  2676  	if tt := v.Type(); tt != tfunc {
  2677  		t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
  2678  	}
  2679  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(17)})[0].Int()
  2680  	if i != 425 {
  2681  		t.Errorf("Interface MethodByName returned %d; want 425", i)
  2682  	}
  2683  
  2684  	// For issue #33628: method args are not stored at the right offset
  2685  	// on amd64p32.
  2686  	m64 := ValueOf(&p).MethodByName("Int64Method").Interface().(func(int64) int64)
  2687  	if x := m64(123); x != 123 {
  2688  		t.Errorf("Int64Method returned %d; want 123", x)
  2689  	}
  2690  	m32 := ValueOf(&p).MethodByName("Int32Method").Interface().(func(int32) int32)
  2691  	if x := m32(456); x != 456 {
  2692  		t.Errorf("Int32Method returned %d; want 456", x)
  2693  	}
  2694  }
  2695  
  2696  func TestVariadicMethodValue(t *testing.T) {
  2697  	p := Point{3, 4}
  2698  	points := []Point{{20, 21}, {22, 23}, {24, 25}}
  2699  	want := int64(p.TotalDist(points[0], points[1], points[2]))
  2700  
  2701  	// Variadic method of type.
  2702  	tfunc := TypeOf((func(Point, ...Point) int)(nil))
  2703  	if tt := TypeOf(p).Method(4).Type; tt != tfunc {
  2704  		t.Errorf("Variadic Method Type from TypeOf is %s; want %s", tt, tfunc)
  2705  	}
  2706  
  2707  	// Curried method of value.
  2708  	tfunc = TypeOf((func(...Point) int)(nil))
  2709  	v := ValueOf(p).Method(4)
  2710  	if tt := v.Type(); tt != tfunc {
  2711  		t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc)
  2712  	}
  2713  	i := ValueOf(v.Interface()).Call([]Value{ValueOf(points[0]), ValueOf(points[1]), ValueOf(points[2])})[0].Int()
  2714  	if i != want {
  2715  		t.Errorf("Variadic Method returned %d; want %d", i, want)
  2716  	}
  2717  	i = ValueOf(v.Interface()).CallSlice([]Value{ValueOf(points)})[0].Int()
  2718  	if i != want {
  2719  		t.Errorf("Variadic Method CallSlice returned %d; want %d", i, want)
  2720  	}
  2721  
  2722  	f := v.Interface().(func(...Point) int)
  2723  	i = int64(f(points[0], points[1], points[2]))
  2724  	if i != want {
  2725  		t.Errorf("Variadic Method Interface returned %d; want %d", i, want)
  2726  	}
  2727  	i = int64(f(points...))
  2728  	if i != want {
  2729  		t.Errorf("Variadic Method Interface Slice returned %d; want %d", i, want)
  2730  	}
  2731  }
  2732  
  2733  type DirectIfaceT struct {
  2734  	p *int
  2735  }
  2736  
  2737  func (d DirectIfaceT) M() int { return *d.p }
  2738  
  2739  func TestDirectIfaceMethod(t *testing.T) {
  2740  	x := 42
  2741  	v := DirectIfaceT{&x}
  2742  	typ := TypeOf(v)
  2743  	m, ok := typ.MethodByName("M")
  2744  	if !ok {
  2745  		t.Fatalf("cannot find method M")
  2746  	}
  2747  	in := []Value{ValueOf(v)}
  2748  	out := m.Func.Call(in)
  2749  	if got := out[0].Int(); got != 42 {
  2750  		t.Errorf("Call with value receiver got %d, want 42", got)
  2751  	}
  2752  
  2753  	pv := &v
  2754  	typ = TypeOf(pv)
  2755  	m, ok = typ.MethodByName("M")
  2756  	if !ok {
  2757  		t.Fatalf("cannot find method M")
  2758  	}
  2759  	in = []Value{ValueOf(pv)}
  2760  	out = m.Func.Call(in)
  2761  	if got := out[0].Int(); got != 42 {
  2762  		t.Errorf("Call with pointer receiver got %d, want 42", got)
  2763  	}
  2764  }
  2765  
  2766  // Reflect version of $GOROOT/test/method5.go
  2767  
  2768  // Concrete types implementing M method.
  2769  // Smaller than a word, word-sized, larger than a word.
  2770  // Value and pointer receivers.
  2771  
  2772  type Tinter interface {
  2773  	M(int, byte) (byte, int)
  2774  }
  2775  
  2776  type Tsmallv byte
  2777  
  2778  func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) }
  2779  
  2780  type Tsmallp byte
  2781  
  2782  func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
  2783  
  2784  type Twordv uintptr
  2785  
  2786  func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) }
  2787  
  2788  type Twordp uintptr
  2789  
  2790  func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
  2791  
  2792  type Tbigv [2]uintptr
  2793  
  2794  func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }
  2795  
  2796  type Tbigp [2]uintptr
  2797  
  2798  func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }
  2799  
  2800  type tinter interface {
  2801  	m(int, byte) (byte, int)
  2802  }
  2803  
  2804  // Embedding via pointer.
  2805  
  2806  type Tm1 struct {
  2807  	Tm2
  2808  }
  2809  
  2810  type Tm2 struct {
  2811  	*Tm3
  2812  }
  2813  
  2814  type Tm3 struct {
  2815  	*Tm4
  2816  }
  2817  
  2818  type Tm4 struct {
  2819  }
  2820  
  2821  func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 }
  2822  
  2823  func TestMethod5(t *testing.T) {
  2824  	CheckF := func(name string, f func(int, byte) (byte, int), inc int) {
  2825  		b, x := f(1000, 99)
  2826  		if b != 99 || x != 1000+inc {
  2827  			t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
  2828  		}
  2829  	}
  2830  
  2831  	CheckV := func(name string, i Value, inc int) {
  2832  		bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))})
  2833  		b := bx[0].Interface()
  2834  		x := bx[1].Interface()
  2835  		if b != byte(99) || x != 1000+inc {
  2836  			t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
  2837  		}
  2838  
  2839  		CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc)
  2840  	}
  2841  
  2842  	var TinterType = TypeOf(new(Tinter)).Elem()
  2843  
  2844  	CheckI := func(name string, i any, inc int) {
  2845  		v := ValueOf(i)
  2846  		CheckV(name, v, inc)
  2847  		CheckV("(i="+name+")", v.Convert(TinterType), inc)
  2848  	}
  2849  
  2850  	sv := Tsmallv(1)
  2851  	CheckI("sv", sv, 1)
  2852  	CheckI("&sv", &sv, 1)
  2853  
  2854  	sp := Tsmallp(2)
  2855  	CheckI("&sp", &sp, 2)
  2856  
  2857  	wv := Twordv(3)
  2858  	CheckI("wv", wv, 3)
  2859  	CheckI("&wv", &wv, 3)
  2860  
  2861  	wp := Twordp(4)
  2862  	CheckI("&wp", &wp, 4)
  2863  
  2864  	bv := Tbigv([2]uintptr{5, 6})
  2865  	CheckI("bv", bv, 11)
  2866  	CheckI("&bv", &bv, 11)
  2867  
  2868  	bp := Tbigp([2]uintptr{7, 8})
  2869  	CheckI("&bp", &bp, 15)
  2870  
  2871  	t4 := Tm4{}
  2872  	t3 := Tm3{&t4}
  2873  	t2 := Tm2{&t3}
  2874  	t1 := Tm1{t2}
  2875  	CheckI("t4", t4, 40)
  2876  	CheckI("&t4", &t4, 40)
  2877  	CheckI("t3", t3, 40)
  2878  	CheckI("&t3", &t3, 40)
  2879  	CheckI("t2", t2, 40)
  2880  	CheckI("&t2", &t2, 40)
  2881  	CheckI("t1", t1, 40)
  2882  	CheckI("&t1", &t1, 40)
  2883  
  2884  	var tnil Tinter
  2885  	vnil := ValueOf(&tnil).Elem()
  2886  	shouldPanic("Method", func() { vnil.Method(0) })
  2887  }
  2888  
  2889  func TestInterfaceSet(t *testing.T) {
  2890  	p := &Point{3, 4}
  2891  
  2892  	var s struct {
  2893  		I any
  2894  		P interface {
  2895  			Dist(int) int
  2896  		}
  2897  	}
  2898  	sv := ValueOf(&s).Elem()
  2899  	sv.Field(0).Set(ValueOf(p))
  2900  	if q := s.I.(*Point); q != p {
  2901  		t.Errorf("i: have %p want %p", q, p)
  2902  	}
  2903  
  2904  	pv := sv.Field(1)
  2905  	pv.Set(ValueOf(p))
  2906  	if q := s.P.(*Point); q != p {
  2907  		t.Errorf("i: have %p want %p", q, p)
  2908  	}
  2909  
  2910  	i := pv.Method(0).Call([]Value{ValueOf(10)})[0].Int()
  2911  	if i != 250 {
  2912  		t.Errorf("Interface Method returned %d; want 250", i)
  2913  	}
  2914  }
  2915  
  2916  type T1 struct {
  2917  	a string
  2918  	int
  2919  }
  2920  
  2921  func TestAnonymousFields(t *testing.T) {
  2922  	var field StructField
  2923  	var ok bool
  2924  	var t1 T1
  2925  	type1 := TypeOf(t1)
  2926  	if field, ok = type1.FieldByName("int"); !ok {
  2927  		t.Fatal("no field 'int'")
  2928  	}
  2929  	if field.Index[0] != 1 {
  2930  		t.Error("field index should be 1; is", field.Index)
  2931  	}
  2932  }
  2933  
  2934  type FTest struct {
  2935  	s     any
  2936  	name  string
  2937  	index []int
  2938  	value int
  2939  }
  2940  
  2941  type D1 struct {
  2942  	d int
  2943  }
  2944  type D2 struct {
  2945  	d int
  2946  }
  2947  
  2948  type S0 struct {
  2949  	A, B, C int
  2950  	D1
  2951  	D2
  2952  }
  2953  
  2954  type S1 struct {
  2955  	B int
  2956  	S0
  2957  }
  2958  
  2959  type S2 struct {
  2960  	A int
  2961  	*S1
  2962  }
  2963  
  2964  type S1x struct {
  2965  	S1
  2966  }
  2967  
  2968  type S1y struct {
  2969  	S1
  2970  }
  2971  
  2972  type S3 struct {
  2973  	S1x
  2974  	S2
  2975  	D, E int
  2976  	*S1y
  2977  }
  2978  
  2979  type S4 struct {
  2980  	*S4
  2981  	A int
  2982  }
  2983  
  2984  // The X in S6 and S7 annihilate, but they also block the X in S8.S9.
  2985  type S5 struct {
  2986  	S6
  2987  	S7
  2988  	S8
  2989  }
  2990  
  2991  type S6 struct {
  2992  	X int
  2993  }
  2994  
  2995  type S7 S6
  2996  
  2997  type S8 struct {
  2998  	S9
  2999  }
  3000  
  3001  type S9 struct {
  3002  	X int
  3003  	Y int
  3004  }
  3005  
  3006  // The X in S11.S6 and S12.S6 annihilate, but they also block the X in S13.S8.S9.
  3007  type S10 struct {
  3008  	S11
  3009  	S12
  3010  	S13
  3011  }
  3012  
  3013  type S11 struct {
  3014  	S6
  3015  }
  3016  
  3017  type S12 struct {
  3018  	S6
  3019  }
  3020  
  3021  type S13 struct {
  3022  	S8
  3023  }
  3024  
  3025  // The X in S15.S11.S1 and S16.S11.S1 annihilate.
  3026  type S14 struct {
  3027  	S15
  3028  	S16
  3029  }
  3030  
  3031  type S15 struct {
  3032  	S11
  3033  }
  3034  
  3035  type S16 struct {
  3036  	S11
  3037  }
  3038  
  3039  var fieldTests = []FTest{
  3040  	{struct{}{}, "", nil, 0},
  3041  	{struct{}{}, "Foo", nil, 0},
  3042  	{S0{A: 'a'}, "A", []int{0}, 'a'},
  3043  	{S0{}, "D", nil, 0},
  3044  	{S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'},
  3045  	{S1{B: 'b'}, "B", []int{0}, 'b'},
  3046  	{S1{}, "S0", []int{1}, 0},
  3047  	{S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'},
  3048  	{S2{A: 'a'}, "A", []int{0}, 'a'},
  3049  	{S2{}, "S1", []int{1}, 0},
  3050  	{S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'},
  3051  	{S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'},
  3052  	{S2{}, "D", nil, 0},
  3053  	{S3{}, "S1", nil, 0},
  3054  	{S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'},
  3055  	{S3{}, "B", nil, 0},
  3056  	{S3{D: 'd'}, "D", []int{2}, 0},
  3057  	{S3{E: 'e'}, "E", []int{3}, 'e'},
  3058  	{S4{A: 'a'}, "A", []int{1}, 'a'},
  3059  	{S4{}, "B", nil, 0},
  3060  	{S5{}, "X", nil, 0},
  3061  	{S5{}, "Y", []int{2, 0, 1}, 0},
  3062  	{S10{}, "X", nil, 0},
  3063  	{S10{}, "Y", []int{2, 0, 0, 1}, 0},
  3064  	{S14{}, "X", nil, 0},
  3065  }
  3066  
  3067  func TestFieldByIndex(t *testing.T) {
  3068  	for _, test := range fieldTests {
  3069  		s := TypeOf(test.s)
  3070  		f := s.FieldByIndex(test.index)
  3071  		if f.Name != "" {
  3072  			if test.index != nil {
  3073  				if f.Name != test.name {
  3074  					t.Errorf("%s.%s found; want %s", s.Name(), f.Name, test.name)
  3075  				}
  3076  			} else {
  3077  				t.Errorf("%s.%s found", s.Name(), f.Name)
  3078  			}
  3079  		} else if len(test.index) > 0 {
  3080  			t.Errorf("%s.%s not found", s.Name(), test.name)
  3081  		}
  3082  
  3083  		if test.value != 0 {
  3084  			v := ValueOf(test.s).FieldByIndex(test.index)
  3085  			if v.IsValid() {
  3086  				if x, ok := v.Interface().(int); ok {
  3087  					if x != test.value {
  3088  						t.Errorf("%s%v is %d; want %d", s.Name(), test.index, x, test.value)
  3089  					}
  3090  				} else {
  3091  					t.Errorf("%s%v value not an int", s.Name(), test.index)
  3092  				}
  3093  			} else {
  3094  				t.Errorf("%s%v value not found", s.Name(), test.index)
  3095  			}
  3096  		}
  3097  	}
  3098  }
  3099  
  3100  func TestFieldByName(t *testing.T) {
  3101  	for _, test := range fieldTests {
  3102  		s := TypeOf(test.s)
  3103  		f, found := s.FieldByName(test.name)
  3104  		if found {
  3105  			if test.index != nil {
  3106  				// Verify field depth and index.
  3107  				if len(f.Index) != len(test.index) {
  3108  					t.Errorf("%s.%s depth %d; want %d: %v vs %v", s.Name(), test.name, len(f.Index), len(test.index), f.Index, test.index)
  3109  				} else {
  3110  					for i, x := range f.Index {
  3111  						if x != test.index[i] {
  3112  							t.Errorf("%s.%s.Index[%d] is %d; want %d", s.Name(), test.name, i, x, test.index[i])
  3113  						}
  3114  					}
  3115  				}
  3116  			} else {
  3117  				t.Errorf("%s.%s found", s.Name(), f.Name)
  3118  			}
  3119  		} else if len(test.index) > 0 {
  3120  			t.Errorf("%s.%s not found", s.Name(), test.name)
  3121  		}
  3122  
  3123  		if test.value != 0 {
  3124  			v := ValueOf(test.s).FieldByName(test.name)
  3125  			if v.IsValid() {
  3126  				if x, ok := v.Interface().(int); ok {
  3127  					if x != test.value {
  3128  						t.Errorf("%s.%s is %d; want %d", s.Name(), test.name, x, test.value)
  3129  					}
  3130  				} else {
  3131  					t.Errorf("%s.%s value not an int", s.Name(), test.name)
  3132  				}
  3133  			} else {
  3134  				t.Errorf("%s.%s value not found", s.Name(), test.name)
  3135  			}
  3136  		}
  3137  	}
  3138  }
  3139  
  3140  func TestImportPath(t *testing.T) {
  3141  	tests := []struct {
  3142  		t    Type
  3143  		path string
  3144  	}{
  3145  		{TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"},
  3146  		{TypeOf(int(0)), ""},
  3147  		{TypeOf(int8(0)), ""},
  3148  		{TypeOf(int16(0)), ""},
  3149  		{TypeOf(int32(0)), ""},
  3150  		{TypeOf(int64(0)), ""},
  3151  		{TypeOf(uint(0)), ""},
  3152  		{TypeOf(uint8(0)), ""},
  3153  		{TypeOf(uint16(0)), ""},
  3154  		{TypeOf(uint32(0)), ""},
  3155  		{TypeOf(uint64(0)), ""},
  3156  		{TypeOf(uintptr(0)), ""},
  3157  		{TypeOf(float32(0)), ""},
  3158  		{TypeOf(float64(0)), ""},
  3159  		{TypeOf(complex64(0)), ""},
  3160  		{TypeOf(complex128(0)), ""},
  3161  		{TypeOf(byte(0)), ""},
  3162  		{TypeOf(rune(0)), ""},
  3163  		{TypeOf([]byte(nil)), ""},
  3164  		{TypeOf([]rune(nil)), ""},
  3165  		{TypeOf(string("")), ""},
  3166  		{TypeOf((*any)(nil)).Elem(), ""},
  3167  		{TypeOf((*byte)(nil)), ""},
  3168  		{TypeOf((*rune)(nil)), ""},
  3169  		{TypeOf((*int64)(nil)), ""},
  3170  		{TypeOf(map[string]int{}), ""},
  3171  		{TypeOf((*error)(nil)).Elem(), ""},
  3172  		{TypeOf((*Point)(nil)), ""},
  3173  		{TypeOf((*Point)(nil)).Elem(), "reflect_test"},
  3174  	}
  3175  	for _, test := range tests {
  3176  		if path := test.t.PkgPath(); path != test.path {
  3177  			t.Errorf("%v.PkgPath() = %q, want %q", test.t, path, test.path)
  3178  		}
  3179  	}
  3180  }
  3181  
  3182  func TestFieldPkgPath(t *testing.T) {
  3183  	type x int
  3184  	typ := TypeOf(struct {
  3185  		Exported   string
  3186  		unexported string
  3187  		OtherPkgFields
  3188  		int // issue 21702
  3189  		*x  // issue 21122
  3190  	}{})
  3191  
  3192  	type pkgpathTest struct {
  3193  		index    []int
  3194  		pkgPath  string
  3195  		embedded bool
  3196  		exported bool
  3197  	}
  3198  
  3199  	checkPkgPath := func(name string, s []pkgpathTest) {
  3200  		for _, test := range s {
  3201  			f := typ.FieldByIndex(test.index)
  3202  			if got, want := f.PkgPath, test.pkgPath; got != want {
  3203  				t.Errorf("%s: Field(%d).PkgPath = %q, want %q", name, test.index, got, want)
  3204  			}
  3205  			if got, want := f.Anonymous, test.embedded; got != want {
  3206  				t.Errorf("%s: Field(%d).Anonymous = %v, want %v", name, test.index, got, want)
  3207  			}
  3208  			if got, want := f.IsExported(), test.exported; got != want {
  3209  				t.Errorf("%s: Field(%d).IsExported = %v, want %v", name, test.index, got, want)
  3210  			}
  3211  		}
  3212  	}
  3213  
  3214  	checkPkgPath("testStruct", []pkgpathTest{
  3215  		{[]int{0}, "", false, true},              // Exported
  3216  		{[]int{1}, "reflect_test", false, false}, // unexported
  3217  		{[]int{2}, "", true, true},               // OtherPkgFields
  3218  		{[]int{2, 0}, "", false, true},           // OtherExported
  3219  		{[]int{2, 1}, "reflect", false, false},   // otherUnexported
  3220  		{[]int{3}, "reflect_test", true, false},  // int
  3221  		{[]int{4}, "reflect_test", true, false},  // *x
  3222  	})
  3223  
  3224  	type localOtherPkgFields OtherPkgFields
  3225  	typ = TypeOf(localOtherPkgFields{})
  3226  	checkPkgPath("localOtherPkgFields", []pkgpathTest{
  3227  		{[]int{0}, "", false, true},         // OtherExported
  3228  		{[]int{1}, "reflect", false, false}, // otherUnexported
  3229  	})
  3230  }
  3231  
  3232  func TestMethodPkgPath(t *testing.T) {
  3233  	type I interface {
  3234  		x()
  3235  		X()
  3236  	}
  3237  	typ := TypeOf((*interface {
  3238  		I
  3239  		y()
  3240  		Y()
  3241  	})(nil)).Elem()
  3242  
  3243  	tests := []struct {
  3244  		name     string
  3245  		pkgPath  string
  3246  		exported bool
  3247  	}{
  3248  		{"X", "", true},
  3249  		{"Y", "", true},
  3250  		{"x", "reflect_test", false},
  3251  		{"y", "reflect_test", false},
  3252  	}
  3253  
  3254  	for _, test := range tests {
  3255  		m, _ := typ.MethodByName(test.name)
  3256  		if got, want := m.PkgPath, test.pkgPath; got != want {
  3257  			t.Errorf("MethodByName(%q).PkgPath = %q, want %q", test.name, got, want)
  3258  		}
  3259  		if got, want := m.IsExported(), test.exported; got != want {
  3260  			t.Errorf("MethodByName(%q).IsExported = %v, want %v", test.name, got, want)
  3261  		}
  3262  	}
  3263  }
  3264  
  3265  func TestVariadicType(t *testing.T) {
  3266  	// Test example from Type documentation.
  3267  	var f func(x int, y ...float64)
  3268  	typ := TypeOf(f)
  3269  	if typ.NumIn() == 2 && typ.In(0) == TypeOf(int(0)) {
  3270  		sl := typ.In(1)
  3271  		if sl.Kind() == Slice {
  3272  			if sl.Elem() == TypeOf(0.0) {
  3273  				// ok
  3274  				return
  3275  			}
  3276  		}
  3277  	}
  3278  
  3279  	// Failed
  3280  	t.Errorf("want NumIn() = 2, In(0) = int, In(1) = []float64")
  3281  	s := fmt.Sprintf("have NumIn() = %d", typ.NumIn())
  3282  	for i := 0; i < typ.NumIn(); i++ {
  3283  		s += fmt.Sprintf(", In(%d) = %s", i, typ.In(i))
  3284  	}
  3285  	t.Error(s)
  3286  }
  3287  
  3288  type inner struct {
  3289  	x int
  3290  }
  3291  
  3292  type outer struct {
  3293  	y int
  3294  	inner
  3295  }
  3296  
  3297  func (*inner) M() {}
  3298  func (*outer) M() {}
  3299  
  3300  func TestNestedMethods(t *testing.T) {
  3301  	typ := TypeOf((*outer)(nil))
  3302  	if typ.NumMethod() != 1 || typ.Method(0).Func.UnsafePointer() != ValueOf((*outer).M).UnsafePointer() {
  3303  		t.Errorf("Wrong method table for outer: (M=%p)", (*outer).M)
  3304  		for i := 0; i < typ.NumMethod(); i++ {
  3305  			m := typ.Method(i)
  3306  			t.Errorf("\t%d: %s %p\n", i, m.Name, m.Func.UnsafePointer())
  3307  		}
  3308  	}
  3309  }
  3310  
  3311  type unexp struct{}
  3312  
  3313  func (*unexp) f() (int32, int8) { return 7, 7 }
  3314  func (*unexp) g() (int64, int8) { return 8, 8 }
  3315  
  3316  type unexpI interface {
  3317  	f() (int32, int8)
  3318  }
  3319  
  3320  func TestUnexportedMethods(t *testing.T) {
  3321  	typ := TypeOf(new(unexp))
  3322  	if got := typ.NumMethod(); got != 0 {
  3323  		t.Errorf("NumMethod=%d, want 0 satisfied methods", got)
  3324  	}
  3325  
  3326  	typ = TypeOf((*unexpI)(nil))
  3327  	if got := typ.Elem().NumMethod(); got != 1 {
  3328  		t.Errorf("NumMethod=%d, want 1 satisfied methods", got)
  3329  	}
  3330  }
  3331  
  3332  type InnerInt struct {
  3333  	X int
  3334  }
  3335  
  3336  type OuterInt struct {
  3337  	Y int
  3338  	InnerInt
  3339  }
  3340  
  3341  func (i *InnerInt) M() int {
  3342  	return i.X
  3343  }
  3344  
  3345  func TestEmbeddedMethods(t *testing.T) {
  3346  	typ := TypeOf((*OuterInt)(nil))
  3347  	if typ.NumMethod() != 1 || typ.Method(0).Func.UnsafePointer() != ValueOf((*OuterInt).M).UnsafePointer() {
  3348  		t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M)
  3349  		for i := 0; i < typ.NumMethod(); i++ {
  3350  			m := typ.Method(i)
  3351  			t.Errorf("\t%d: %s %p\n", i, m.Name, m.Func.UnsafePointer())
  3352  		}
  3353  	}
  3354  
  3355  	i := &InnerInt{3}
  3356  	if v := ValueOf(i).Method(0).Call(nil)[0].Int(); v != 3 {
  3357  		t.Errorf("i.M() = %d, want 3", v)
  3358  	}
  3359  
  3360  	o := &OuterInt{1, InnerInt{2}}
  3361  	if v := ValueOf(o).Method(0).Call(nil)[0].Int(); v != 2 {
  3362  		t.Errorf("i.M() = %d, want 2", v)
  3363  	}
  3364  
  3365  	f := (*OuterInt).M
  3366  	if v := f(o); v != 2 {
  3367  		t.Errorf("f(o) = %d, want 2", v)
  3368  	}
  3369  }
  3370  
  3371  type FuncDDD func(...any) error
  3372  
  3373  func (f FuncDDD) M() {}
  3374  
  3375  func TestNumMethodOnDDD(t *testing.T) {
  3376  	rv := ValueOf((FuncDDD)(nil))
  3377  	if n := rv.NumMethod(); n != 1 {
  3378  		t.Fatalf("NumMethod()=%d, want 1", n)
  3379  	}
  3380  }
  3381  
  3382  func TestPtrTo(t *testing.T) {
  3383  	// This block of code means that the ptrToThis field of the
  3384  	// reflect data for *unsafe.Pointer is non zero, see
  3385  	// https://golang.org/issue/19003
  3386  	var x unsafe.Pointer
  3387  	var y = &x
  3388  	var z = &y
  3389  
  3390  	var i int
  3391  
  3392  	typ := TypeOf(z)
  3393  	for i = 0; i < 100; i++ {
  3394  		typ = PointerTo(typ)
  3395  	}
  3396  	for i = 0; i < 100; i++ {
  3397  		typ = typ.Elem()
  3398  	}
  3399  	if typ != TypeOf(z) {
  3400  		t.Errorf("after 100 PointerTo and Elem, have %s, want %s", typ, TypeOf(z))
  3401  	}
  3402  }
  3403  
  3404  func TestPtrToGC(t *testing.T) {
  3405  	type T *uintptr
  3406  	tt := TypeOf(T(nil))
  3407  	pt := PointerTo(tt)
  3408  	const n = 100
  3409  	var x []any
  3410  	for i := 0; i < n; i++ {
  3411  		v := New(pt)
  3412  		p := new(*uintptr)
  3413  		*p = new(uintptr)
  3414  		**p = uintptr(i)
  3415  		v.Elem().Set(ValueOf(p).Convert(pt))
  3416  		x = append(x, v.Interface())
  3417  	}
  3418  	runtime.GC()
  3419  
  3420  	for i, xi := range x {
  3421  		k := ValueOf(xi).Elem().Elem().Elem().Interface().(uintptr)
  3422  		if k != uintptr(i) {
  3423  			t.Errorf("lost x[%d] = %d, want %d", i, k, i)
  3424  		}
  3425  	}
  3426  }
  3427  
  3428  func TestAddr(t *testing.T) {
  3429  	var p struct {
  3430  		X, Y int
  3431  	}
  3432  
  3433  	v := ValueOf(&p)
  3434  	v = v.Elem()
  3435  	v = v.Addr()
  3436  	v = v.Elem()
  3437  	v = v.Field(0)
  3438  	v.SetInt(2)
  3439  	if p.X != 2 {
  3440  		t.Errorf("Addr.Elem.Set failed to set value")
  3441  	}
  3442  
  3443  	// Again but take address of the ValueOf value.
  3444  	// Exercises generation of PtrTypes not present in the binary.
  3445  	q := &p
  3446  	v = ValueOf(&q).Elem()
  3447  	v = v.Addr()
  3448  	v = v.Elem()
  3449  	v = v.Elem()
  3450  	v = v.Addr()
  3451  	v = v.Elem()
  3452  	v = v.Field(0)
  3453  	v.SetInt(3)
  3454  	if p.X != 3 {
  3455  		t.Errorf("Addr.Elem.Set failed to set value")
  3456  	}
  3457  
  3458  	// Starting without pointer we should get changed value
  3459  	// in interface.
  3460  	qq := p
  3461  	v = ValueOf(&qq).Elem()
  3462  	v0 := v
  3463  	v = v.Addr()
  3464  	v = v.Elem()
  3465  	v = v.Field(0)
  3466  	v.SetInt(4)
  3467  	if p.X != 3 { // should be unchanged from last time
  3468  		t.Errorf("somehow value Set changed original p")
  3469  	}
  3470  	p = v0.Interface().(struct {
  3471  		X, Y int
  3472  	})
  3473  	if p.X != 4 {
  3474  		t.Errorf("Addr.Elem.Set valued to set value in top value")
  3475  	}
  3476  
  3477  	// Verify that taking the address of a type gives us a pointer
  3478  	// which we can convert back using the usual interface
  3479  	// notation.
  3480  	var s struct {
  3481  		B *bool
  3482  	}
  3483  	ps := ValueOf(&s).Elem().Field(0).Addr().Interface()
  3484  	*(ps.(**bool)) = new(bool)
  3485  	if s.B == nil {
  3486  		t.Errorf("Addr.Interface direct assignment failed")
  3487  	}
  3488  }
  3489  
  3490  func noAlloc(t *testing.T, n int, f func(int)) {
  3491  	if testing.Short() {
  3492  		t.Skip("skipping malloc count in short mode")
  3493  	}
  3494  	if runtime.GOMAXPROCS(0) > 1 {
  3495  		t.Skip("skipping; GOMAXPROCS>1")
  3496  	}
  3497  	i := -1
  3498  	allocs := testing.AllocsPerRun(n, func() {
  3499  		f(i)
  3500  		i++
  3501  	})
  3502  	if allocs > 0 {
  3503  		t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs)
  3504  	}
  3505  }
  3506  
  3507  func TestAllocations(t *testing.T) {
  3508  	noAlloc(t, 100, func(j int) {
  3509  		var i any
  3510  		var v Value
  3511  
  3512  		i = 42 + j
  3513  		v = ValueOf(i)
  3514  		if int(v.Int()) != 42+j {
  3515  			panic("wrong int")
  3516  		}
  3517  	})
  3518  	noAlloc(t, 100, func(j int) {
  3519  		var i any
  3520  		var v Value
  3521  		i = [3]int{j, j, j}
  3522  		v = ValueOf(i)
  3523  		if v.Len() != 3 {
  3524  			panic("wrong length")
  3525  		}
  3526  	})
  3527  	noAlloc(t, 100, func(j int) {
  3528  		var i any
  3529  		var v Value
  3530  		i = func(j int) int { return j }
  3531  		v = ValueOf(i)
  3532  		if v.Interface().(func(int) int)(j) != j {
  3533  			panic("wrong result")
  3534  		}
  3535  	})
  3536  }
  3537  
  3538  func TestSmallNegativeInt(t *testing.T) {
  3539  	i := int16(-1)
  3540  	v := ValueOf(i)
  3541  	if v.Int() != -1 {
  3542  		t.Errorf("int16(-1).Int() returned %v", v.Int())
  3543  	}
  3544  }
  3545  
  3546  func TestIndex(t *testing.T) {
  3547  	xs := []byte{1, 2, 3, 4, 5, 6, 7, 8}
  3548  	v := ValueOf(xs).Index(3).Interface().(byte)
  3549  	if v != xs[3] {
  3550  		t.Errorf("xs.Index(3) = %v; expected %v", v, xs[3])
  3551  	}
  3552  	xa := [8]byte{10, 20, 30, 40, 50, 60, 70, 80}
  3553  	v = ValueOf(xa).Index(2).Interface().(byte)
  3554  	if v != xa[2] {
  3555  		t.Errorf("xa.Index(2) = %v; expected %v", v, xa[2])
  3556  	}
  3557  	s := "0123456789"
  3558  	v = ValueOf(s).Index(3).Interface().(byte)
  3559  	if v != s[3] {
  3560  		t.Errorf("s.Index(3) = %v; expected %v", v, s[3])
  3561  	}
  3562  }
  3563  
  3564  func TestSlice(t *testing.T) {
  3565  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  3566  	v := ValueOf(xs).Slice(3, 5).Interface().([]int)
  3567  	if len(v) != 2 {
  3568  		t.Errorf("len(xs.Slice(3, 5)) = %d", len(v))
  3569  	}
  3570  	if cap(v) != 5 {
  3571  		t.Errorf("cap(xs.Slice(3, 5)) = %d", cap(v))
  3572  	}
  3573  	if !DeepEqual(v[0:5], xs[3:]) {
  3574  		t.Errorf("xs.Slice(3, 5)[0:5] = %v", v[0:5])
  3575  	}
  3576  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  3577  	v = ValueOf(&xa).Elem().Slice(2, 5).Interface().([]int)
  3578  	if len(v) != 3 {
  3579  		t.Errorf("len(xa.Slice(2, 5)) = %d", len(v))
  3580  	}
  3581  	if cap(v) != 6 {
  3582  		t.Errorf("cap(xa.Slice(2, 5)) = %d", cap(v))
  3583  	}
  3584  	if !DeepEqual(v[0:6], xa[2:]) {
  3585  		t.Errorf("xs.Slice(2, 5)[0:6] = %v", v[0:6])
  3586  	}
  3587  	s := "0123456789"
  3588  	vs := ValueOf(s).Slice(3, 5).Interface().(string)
  3589  	if vs != s[3:5] {
  3590  		t.Errorf("s.Slice(3, 5) = %q; expected %q", vs, s[3:5])
  3591  	}
  3592  
  3593  	rv := ValueOf(&xs).Elem()
  3594  	rv = rv.Slice(3, 4)
  3595  	ptr2 := rv.UnsafePointer()
  3596  	rv = rv.Slice(5, 5)
  3597  	ptr3 := rv.UnsafePointer()
  3598  	if ptr3 != ptr2 {
  3599  		t.Errorf("xs.Slice(3,4).Slice3(5,5).UnsafePointer() = %p, want %p", ptr3, ptr2)
  3600  	}
  3601  }
  3602  
  3603  func TestSlice3(t *testing.T) {
  3604  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  3605  	v := ValueOf(xs).Slice3(3, 5, 7).Interface().([]int)
  3606  	if len(v) != 2 {
  3607  		t.Errorf("len(xs.Slice3(3, 5, 7)) = %d", len(v))
  3608  	}
  3609  	if cap(v) != 4 {
  3610  		t.Errorf("cap(xs.Slice3(3, 5, 7)) = %d", cap(v))
  3611  	}
  3612  	if !DeepEqual(v[0:4], xs[3:7:7]) {
  3613  		t.Errorf("xs.Slice3(3, 5, 7)[0:4] = %v", v[0:4])
  3614  	}
  3615  	rv := ValueOf(&xs).Elem()
  3616  	shouldPanic("Slice3", func() { rv.Slice3(1, 2, 1) })
  3617  	shouldPanic("Slice3", func() { rv.Slice3(1, 1, 11) })
  3618  	shouldPanic("Slice3", func() { rv.Slice3(2, 2, 1) })
  3619  
  3620  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  3621  	v = ValueOf(&xa).Elem().Slice3(2, 5, 6).Interface().([]int)
  3622  	if len(v) != 3 {
  3623  		t.Errorf("len(xa.Slice(2, 5, 6)) = %d", len(v))
  3624  	}
  3625  	if cap(v) != 4 {
  3626  		t.Errorf("cap(xa.Slice(2, 5, 6)) = %d", cap(v))
  3627  	}
  3628  	if !DeepEqual(v[0:4], xa[2:6:6]) {
  3629  		t.Errorf("xs.Slice(2, 5, 6)[0:4] = %v", v[0:4])
  3630  	}
  3631  	rv = ValueOf(&xa).Elem()
  3632  	shouldPanic("Slice3", func() { rv.Slice3(1, 2, 1) })
  3633  	shouldPanic("Slice3", func() { rv.Slice3(1, 1, 11) })
  3634  	shouldPanic("Slice3", func() { rv.Slice3(2, 2, 1) })
  3635  
  3636  	s := "hello world"
  3637  	rv = ValueOf(&s).Elem()
  3638  	shouldPanic("Slice3", func() { rv.Slice3(1, 2, 3) })
  3639  
  3640  	rv = ValueOf(&xs).Elem()
  3641  	rv = rv.Slice3(3, 5, 7)
  3642  	ptr2 := rv.UnsafePointer()
  3643  	rv = rv.Slice3(4, 4, 4)
  3644  	ptr3 := rv.UnsafePointer()
  3645  	if ptr3 != ptr2 {
  3646  		t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).UnsafePointer() = %p, want %p", ptr3, ptr2)
  3647  	}
  3648  }
  3649  
  3650  func TestSetLenCap(t *testing.T) {
  3651  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  3652  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  3653  
  3654  	vs := ValueOf(&xs).Elem()
  3655  	shouldPanic("SetLen", func() { vs.SetLen(10) })
  3656  	shouldPanic("SetCap", func() { vs.SetCap(10) })
  3657  	shouldPanic("SetLen", func() { vs.SetLen(-1) })
  3658  	shouldPanic("SetCap", func() { vs.SetCap(-1) })
  3659  	shouldPanic("SetCap", func() { vs.SetCap(6) }) // smaller than len
  3660  	vs.SetLen(5)
  3661  	if len(xs) != 5 || cap(xs) != 8 {
  3662  		t.Errorf("after SetLen(5), len, cap = %d, %d, want 5, 8", len(xs), cap(xs))
  3663  	}
  3664  	vs.SetCap(6)
  3665  	if len(xs) != 5 || cap(xs) != 6 {
  3666  		t.Errorf("after SetCap(6), len, cap = %d, %d, want 5, 6", len(xs), cap(xs))
  3667  	}
  3668  	vs.SetCap(5)
  3669  	if len(xs) != 5 || cap(xs) != 5 {
  3670  		t.Errorf("after SetCap(5), len, cap = %d, %d, want 5, 5", len(xs), cap(xs))
  3671  	}
  3672  	shouldPanic("SetCap", func() { vs.SetCap(4) }) // smaller than len
  3673  	shouldPanic("SetLen", func() { vs.SetLen(6) }) // bigger than cap
  3674  
  3675  	va := ValueOf(&xa).Elem()
  3676  	shouldPanic("SetLen", func() { va.SetLen(8) })
  3677  	shouldPanic("SetCap", func() { va.SetCap(8) })
  3678  }
  3679  
  3680  func TestVariadic(t *testing.T) {
  3681  	var b strings.Builder
  3682  	V := ValueOf
  3683  
  3684  	b.Reset()
  3685  	V(fmt.Fprintf).Call([]Value{V(&b), V("%s, %d world"), V("hello"), V(42)})
  3686  	if b.String() != "hello, 42 world" {
  3687  		t.Errorf("after Fprintf Call: %q != %q", b.String(), "hello 42 world")
  3688  	}
  3689  
  3690  	b.Reset()
  3691  	V(fmt.Fprintf).CallSlice([]Value{V(&b), V("%s, %d world"), V([]any{"hello", 42})})
  3692  	if b.String() != "hello, 42 world" {
  3693  		t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world")
  3694  	}
  3695  }
  3696  
  3697  func TestFuncArg(t *testing.T) {
  3698  	f1 := func(i int, f func(int) int) int { return f(i) }
  3699  	f2 := func(i int) int { return i + 1 }
  3700  	r := ValueOf(f1).Call([]Value{ValueOf(100), ValueOf(f2)})
  3701  	if r[0].Int() != 101 {
  3702  		t.Errorf("function returned %d, want 101", r[0].Int())
  3703  	}
  3704  }
  3705  
  3706  func TestStructArg(t *testing.T) {
  3707  	type padded struct {
  3708  		B string
  3709  		C int32
  3710  	}
  3711  	var (
  3712  		gotA  padded
  3713  		gotB  uint32
  3714  		wantA = padded{"3", 4}
  3715  		wantB = uint32(5)
  3716  	)
  3717  	f := func(a padded, b uint32) {
  3718  		gotA, gotB = a, b
  3719  	}
  3720  	ValueOf(f).Call([]Value{ValueOf(wantA), ValueOf(wantB)})
  3721  	if gotA != wantA || gotB != wantB {
  3722  		t.Errorf("function called with (%v, %v), want (%v, %v)", gotA, gotB, wantA, wantB)
  3723  	}
  3724  }
  3725  
  3726  var tagGetTests = []struct {
  3727  	Tag   StructTag
  3728  	Key   string
  3729  	Value string
  3730  }{
  3731  	{`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`},
  3732  	{`protobuf:"PB(1,2)"`, `foo`, ``},
  3733  	{`protobuf:"PB(1,2)"`, `rotobuf`, ``},
  3734  	{`protobuf:"PB(1,2)" json:"name"`, `json`, `name`},
  3735  	{`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`},
  3736  	{`k0:"values contain spaces" k1:"and\ttabs"`, "k0", "values contain spaces"},
  3737  	{`k0:"values contain spaces" k1:"and\ttabs"`, "k1", "and\ttabs"},
  3738  }
  3739  
  3740  func TestTagGet(t *testing.T) {
  3741  	for _, tt := range tagGetTests {
  3742  		if v := tt.Tag.Get(tt.Key); v != tt.Value {
  3743  			t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value)
  3744  		}
  3745  	}
  3746  }
  3747  
  3748  func TestBytes(t *testing.T) {
  3749  	shouldPanic("on int Value", func() { ValueOf(0).Bytes() })
  3750  	shouldPanic("of non-byte slice", func() { ValueOf([]string{}).Bytes() })
  3751  
  3752  	type S []byte
  3753  	x := S{1, 2, 3, 4}
  3754  	y := ValueOf(x).Bytes()
  3755  	if !bytes.Equal(x, y) {
  3756  		t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
  3757  	}
  3758  	if &x[0] != &y[0] {
  3759  		t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
  3760  	}
  3761  
  3762  	type A [4]byte
  3763  	a := A{1, 2, 3, 4}
  3764  	shouldPanic("unaddressable", func() { ValueOf(a).Bytes() })
  3765  	shouldPanic("on ptr Value", func() { ValueOf(&a).Bytes() })
  3766  	b := ValueOf(&a).Elem().Bytes()
  3767  	if !bytes.Equal(a[:], y) {
  3768  		t.Fatalf("ValueOf(%v).Bytes() = %v", a, b)
  3769  	}
  3770  	if &a[0] != &b[0] {
  3771  		t.Errorf("ValueOf(%p).Bytes() = %p", &a[0], &b[0])
  3772  	}
  3773  
  3774  	// Per issue #24746, it was decided that Bytes can be called on byte slices
  3775  	// that normally cannot be converted from per Go language semantics.
  3776  	type B byte
  3777  	type SB []B
  3778  	type AB [4]B
  3779  	ValueOf([]B{1, 2, 3, 4}).Bytes()  // should not panic
  3780  	ValueOf(new([4]B)).Elem().Bytes() // should not panic
  3781  	ValueOf(SB{1, 2, 3, 4}).Bytes()   // should not panic
  3782  	ValueOf(new(AB)).Elem().Bytes()   // should not panic
  3783  }
  3784  
  3785  func TestSetBytes(t *testing.T) {
  3786  	type B []byte
  3787  	var x B
  3788  	y := []byte{1, 2, 3, 4}
  3789  	ValueOf(&x).Elem().SetBytes(y)
  3790  	if !bytes.Equal(x, y) {
  3791  		t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
  3792  	}
  3793  	if &x[0] != &y[0] {
  3794  		t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
  3795  	}
  3796  }
  3797  
  3798  type Private struct {
  3799  	x int
  3800  	y **int
  3801  	Z int
  3802  }
  3803  
  3804  func (p *Private) m() {
  3805  }
  3806  
  3807  type private struct {
  3808  	Z int
  3809  	z int
  3810  	S string
  3811  	A [1]Private
  3812  	T []Private
  3813  }
  3814  
  3815  func (p *private) P() {
  3816  }
  3817  
  3818  type Public struct {
  3819  	X int
  3820  	Y **int
  3821  	private
  3822  }
  3823  
  3824  func (p *Public) M() {
  3825  }
  3826  
  3827  func TestUnexported(t *testing.T) {
  3828  	var pub Public
  3829  	pub.S = "S"
  3830  	pub.T = pub.A[:]
  3831  	v := ValueOf(&pub)
  3832  	isValid(v.Elem().Field(0))
  3833  	isValid(v.Elem().Field(1))
  3834  	isValid(v.Elem().Field(2))
  3835  	isValid(v.Elem().FieldByName("X"))
  3836  	isValid(v.Elem().FieldByName("Y"))
  3837  	isValid(v.Elem().FieldByName("Z"))
  3838  	isValid(v.Type().Method(0).Func)
  3839  	m, _ := v.Type().MethodByName("M")
  3840  	isValid(m.Func)
  3841  	m, _ = v.Type().MethodByName("P")
  3842  	isValid(m.Func)
  3843  	isNonNil(v.Elem().Field(0).Interface())
  3844  	isNonNil(v.Elem().Field(1).Interface())
  3845  	isNonNil(v.Elem().Field(2).Field(2).Index(0))
  3846  	isNonNil(v.Elem().FieldByName("X").Interface())
  3847  	isNonNil(v.Elem().FieldByName("Y").Interface())
  3848  	isNonNil(v.Elem().FieldByName("Z").Interface())
  3849  	isNonNil(v.Elem().FieldByName("S").Index(0).Interface())
  3850  	isNonNil(v.Type().Method(0).Func.Interface())
  3851  	m, _ = v.Type().MethodByName("P")
  3852  	isNonNil(m.Func.Interface())
  3853  
  3854  	var priv Private
  3855  	v = ValueOf(&priv)
  3856  	isValid(v.Elem().Field(0))
  3857  	isValid(v.Elem().Field(1))
  3858  	isValid(v.Elem().FieldByName("x"))
  3859  	isValid(v.Elem().FieldByName("y"))
  3860  	shouldPanic("Interface", func() { v.Elem().Field(0).Interface() })
  3861  	shouldPanic("Interface", func() { v.Elem().Field(1).Interface() })
  3862  	shouldPanic("Interface", func() { v.Elem().FieldByName("x").Interface() })
  3863  	shouldPanic("Interface", func() { v.Elem().FieldByName("y").Interface() })
  3864  	shouldPanic("Method", func() { v.Type().Method(0) })
  3865  }
  3866  
  3867  func TestSetPanic(t *testing.T) {
  3868  	ok := func(f func()) { f() }
  3869  	bad := func(f func()) { shouldPanic("Set", f) }
  3870  	clear := func(v Value) { v.Set(Zero(v.Type())) }
  3871  
  3872  	type t0 struct {
  3873  		W int
  3874  	}
  3875  
  3876  	type t1 struct {
  3877  		Y int
  3878  		t0
  3879  	}
  3880  
  3881  	type T2 struct {
  3882  		Z       int
  3883  		namedT0 t0
  3884  	}
  3885  
  3886  	type T struct {
  3887  		X int
  3888  		t1
  3889  		T2
  3890  		NamedT1 t1
  3891  		NamedT2 T2
  3892  		namedT1 t1
  3893  		namedT2 T2
  3894  	}
  3895  
  3896  	// not addressable
  3897  	v := ValueOf(T{})
  3898  	bad(func() { clear(v.Field(0)) })                   // .X
  3899  	bad(func() { clear(v.Field(1)) })                   // .t1
  3900  	bad(func() { clear(v.Field(1).Field(0)) })          // .t1.Y
  3901  	bad(func() { clear(v.Field(1).Field(1)) })          // .t1.t0
  3902  	bad(func() { clear(v.Field(1).Field(1).Field(0)) }) // .t1.t0.W
  3903  	bad(func() { clear(v.Field(2)) })                   // .T2
  3904  	bad(func() { clear(v.Field(2).Field(0)) })          // .T2.Z
  3905  	bad(func() { clear(v.Field(2).Field(1)) })          // .T2.namedT0
  3906  	bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W
  3907  	bad(func() { clear(v.Field(3)) })                   // .NamedT1
  3908  	bad(func() { clear(v.Field(3).Field(0)) })          // .NamedT1.Y
  3909  	bad(func() { clear(v.Field(3).Field(1)) })          // .NamedT1.t0
  3910  	bad(func() { clear(v.Field(3).Field(1).Field(0)) }) // .NamedT1.t0.W
  3911  	bad(func() { clear(v.Field(4)) })                   // .NamedT2
  3912  	bad(func() { clear(v.Field(4).Field(0)) })          // .NamedT2.Z
  3913  	bad(func() { clear(v.Field(4).Field(1)) })          // .NamedT2.namedT0
  3914  	bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W
  3915  	bad(func() { clear(v.Field(5)) })                   // .namedT1
  3916  	bad(func() { clear(v.Field(5).Field(0)) })          // .namedT1.Y
  3917  	bad(func() { clear(v.Field(5).Field(1)) })          // .namedT1.t0
  3918  	bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W
  3919  	bad(func() { clear(v.Field(6)) })                   // .namedT2
  3920  	bad(func() { clear(v.Field(6).Field(0)) })          // .namedT2.Z
  3921  	bad(func() { clear(v.Field(6).Field(1)) })          // .namedT2.namedT0
  3922  	bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W
  3923  
  3924  	// addressable
  3925  	v = ValueOf(&T{}).Elem()
  3926  	ok(func() { clear(v.Field(0)) })                    // .X
  3927  	bad(func() { clear(v.Field(1)) })                   // .t1
  3928  	ok(func() { clear(v.Field(1).Field(0)) })           // .t1.Y
  3929  	bad(func() { clear(v.Field(1).Field(1)) })          // .t1.t0
  3930  	ok(func() { clear(v.Field(1).Field(1).Field(0)) })  // .t1.t0.W
  3931  	ok(func() { clear(v.Field(2)) })                    // .T2
  3932  	ok(func() { clear(v.Field(2).Field(0)) })           // .T2.Z
  3933  	bad(func() { clear(v.Field(2).Field(1)) })          // .T2.namedT0
  3934  	bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W
  3935  	ok(func() { clear(v.Field(3)) })                    // .NamedT1
  3936  	ok(func() { clear(v.Field(3).Field(0)) })           // .NamedT1.Y
  3937  	bad(func() { clear(v.Field(3).Field(1)) })          // .NamedT1.t0
  3938  	ok(func() { clear(v.Field(3).Field(1).Field(0)) })  // .NamedT1.t0.W
  3939  	ok(func() { clear(v.Field(4)) })                    // .NamedT2
  3940  	ok(func() { clear(v.Field(4).Field(0)) })           // .NamedT2.Z
  3941  	bad(func() { clear(v.Field(4).Field(1)) })          // .NamedT2.namedT0
  3942  	bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W
  3943  	bad(func() { clear(v.Field(5)) })                   // .namedT1
  3944  	bad(func() { clear(v.Field(5).Field(0)) })          // .namedT1.Y
  3945  	bad(func() { clear(v.Field(5).Field(1)) })          // .namedT1.t0
  3946  	bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W
  3947  	bad(func() { clear(v.Field(6)) })                   // .namedT2
  3948  	bad(func() { clear(v.Field(6).Field(0)) })          // .namedT2.Z
  3949  	bad(func() { clear(v.Field(6).Field(1)) })          // .namedT2.namedT0
  3950  	bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W
  3951  }
  3952  
  3953  type timp int
  3954  
  3955  func (t timp) W() {}
  3956  func (t timp) Y() {}
  3957  func (t timp) w() {}
  3958  func (t timp) y() {}
  3959  
  3960  func TestCallPanic(t *testing.T) {
  3961  	type t0 interface {
  3962  		W()
  3963  		w()
  3964  	}
  3965  	type T1 interface {
  3966  		Y()
  3967  		y()
  3968  	}
  3969  	type T2 struct {
  3970  		T1
  3971  		t0
  3972  	}
  3973  	type T struct {
  3974  		t0 // 0
  3975  		T1 // 1
  3976  
  3977  		NamedT0 t0 // 2
  3978  		NamedT1 T1 // 3
  3979  		NamedT2 T2 // 4
  3980  
  3981  		namedT0 t0 // 5
  3982  		namedT1 T1 // 6
  3983  		namedT2 T2 // 7
  3984  	}
  3985  	ok := func(f func()) { f() }
  3986  	badCall := func(f func()) { shouldPanic("Call", f) }
  3987  	badMethod := func(f func()) { shouldPanic("Method", f) }
  3988  	call := func(v Value) { v.Call(nil) }
  3989  
  3990  	i := timp(0)
  3991  	v := ValueOf(T{i, i, i, i, T2{i, i}, i, i, T2{i, i}})
  3992  	badCall(func() { call(v.Field(0).Method(0)) })          // .t0.W
  3993  	badCall(func() { call(v.Field(0).Elem().Method(0)) })   // .t0.W
  3994  	badCall(func() { call(v.Field(0).Method(1)) })          // .t0.w
  3995  	badMethod(func() { call(v.Field(0).Elem().Method(2)) }) // .t0.w
  3996  	ok(func() { call(v.Field(1).Method(0)) })               // .T1.Y
  3997  	ok(func() { call(v.Field(1).Elem().Method(0)) })        // .T1.Y
  3998  	badCall(func() { call(v.Field(1).Method(1)) })          // .T1.y
  3999  	badMethod(func() { call(v.Field(1).Elem().Method(2)) }) // .T1.y
  4000  
  4001  	ok(func() { call(v.Field(2).Method(0)) })               // .NamedT0.W
  4002  	ok(func() { call(v.Field(2).Elem().Method(0)) })        // .NamedT0.W
  4003  	badCall(func() { call(v.Field(2).Method(1)) })          // .NamedT0.w
  4004  	badMethod(func() { call(v.Field(2).Elem().Method(2)) }) // .NamedT0.w
  4005  
  4006  	ok(func() { call(v.Field(3).Method(0)) })               // .NamedT1.Y
  4007  	ok(func() { call(v.Field(3).Elem().Method(0)) })        // .NamedT1.Y
  4008  	badCall(func() { call(v.Field(3).Method(1)) })          // .NamedT1.y
  4009  	badMethod(func() { call(v.Field(3).Elem().Method(3)) }) // .NamedT1.y
  4010  
  4011  	ok(func() { call(v.Field(4).Field(0).Method(0)) })             // .NamedT2.T1.Y
  4012  	ok(func() { call(v.Field(4).Field(0).Elem().Method(0)) })      // .NamedT2.T1.W
  4013  	badCall(func() { call(v.Field(4).Field(1).Method(0)) })        // .NamedT2.t0.W
  4014  	badCall(func() { call(v.Field(4).Field(1).Elem().Method(0)) }) // .NamedT2.t0.W
  4015  
  4016  	badCall(func() { call(v.Field(5).Method(0)) })          // .namedT0.W
  4017  	badCall(func() { call(v.Field(5).Elem().Method(0)) })   // .namedT0.W
  4018  	badCall(func() { call(v.Field(5).Method(1)) })          // .namedT0.w
  4019  	badMethod(func() { call(v.Field(5).Elem().Method(2)) }) // .namedT0.w
  4020  
  4021  	badCall(func() { call(v.Field(6).Method(0)) })        // .namedT1.Y
  4022  	badCall(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.Y
  4023  	badCall(func() { call(v.Field(6).Method(0)) })        // .namedT1.y
  4024  	badCall(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.y
  4025  
  4026  	badCall(func() { call(v.Field(7).Field(0).Method(0)) })        // .namedT2.T1.Y
  4027  	badCall(func() { call(v.Field(7).Field(0).Elem().Method(0)) }) // .namedT2.T1.W
  4028  	badCall(func() { call(v.Field(7).Field(1).Method(0)) })        // .namedT2.t0.W
  4029  	badCall(func() { call(v.Field(7).Field(1).Elem().Method(0)) }) // .namedT2.t0.W
  4030  }
  4031  
  4032  func TestValuePanic(t *testing.T) {
  4033  	vo := ValueOf
  4034  	shouldPanic("reflect.Value.Addr of unaddressable value", func() { vo(0).Addr() })
  4035  	shouldPanic("call of reflect.Value.Bool on float64 Value", func() { vo(0.0).Bool() })
  4036  	shouldPanic("call of reflect.Value.Bytes on string Value", func() { vo("").Bytes() })
  4037  	shouldPanic("call of reflect.Value.Call on bool Value", func() { vo(true).Call(nil) })
  4038  	shouldPanic("call of reflect.Value.CallSlice on int Value", func() { vo(0).CallSlice(nil) })
  4039  	shouldPanic("call of reflect.Value.Close on string Value", func() { vo("").Close() })
  4040  	shouldPanic("call of reflect.Value.Complex on float64 Value", func() { vo(0.0).Complex() })
  4041  	shouldPanic("call of reflect.Value.Elem on bool Value", func() { vo(false).Elem() })
  4042  	shouldPanic("call of reflect.Value.Field on int Value", func() { vo(0).Field(0) })
  4043  	shouldPanic("call of reflect.Value.Float on string Value", func() { vo("").Float() })
  4044  	shouldPanic("call of reflect.Value.Index on float64 Value", func() { vo(0.0).Index(0) })
  4045  	shouldPanic("call of reflect.Value.Int on bool Value", func() { vo(false).Int() })
  4046  	shouldPanic("call of reflect.Value.IsNil on int Value", func() { vo(0).IsNil() })
  4047  	shouldPanic("call of reflect.Value.Len on bool Value", func() { vo(false).Len() })
  4048  	shouldPanic("call of reflect.Value.MapIndex on float64 Value", func() { vo(0.0).MapIndex(vo(0.0)) })
  4049  	shouldPanic("call of reflect.Value.MapKeys on string Value", func() { vo("").MapKeys() })
  4050  	shouldPanic("call of reflect.Value.MapRange on int Value", func() { vo(0).MapRange() })
  4051  	shouldPanic("call of reflect.Value.Method on zero Value", func() { vo(nil).Method(0) })
  4052  	shouldPanic("call of reflect.Value.NumField on string Value", func() { vo("").NumField() })
  4053  	shouldPanic("call of reflect.Value.NumMethod on zero Value", func() { vo(nil).NumMethod() })
  4054  	shouldPanic("call of reflect.Value.OverflowComplex on float64 Value", func() { vo(float64(0)).OverflowComplex(0) })
  4055  	shouldPanic("call of reflect.Value.OverflowFloat on int64 Value", func() { vo(int64(0)).OverflowFloat(0) })
  4056  	shouldPanic("call of reflect.Value.OverflowInt on uint64 Value", func() { vo(uint64(0)).OverflowInt(0) })
  4057  	shouldPanic("call of reflect.Value.OverflowUint on complex64 Value", func() { vo(complex64(0)).OverflowUint(0) })
  4058  	shouldPanic("call of reflect.Value.Recv on string Value", func() { vo("").Recv() })
  4059  	shouldPanic("call of reflect.Value.Send on bool Value", func() { vo(true).Send(vo(true)) })
  4060  	shouldPanic("value of type string is not assignable to type bool", func() { vo(new(bool)).Elem().Set(vo("")) })
  4061  	shouldPanic("call of reflect.Value.SetBool on string Value", func() { vo(new(string)).Elem().SetBool(false) })
  4062  	shouldPanic("reflect.Value.SetBytes using unaddressable value", func() { vo("").SetBytes(nil) })
  4063  	shouldPanic("call of reflect.Value.SetCap on string Value", func() { vo(new(string)).Elem().SetCap(0) })
  4064  	shouldPanic("call of reflect.Value.SetComplex on string Value", func() { vo(new(string)).Elem().SetComplex(0) })
  4065  	shouldPanic("call of reflect.Value.SetFloat on string Value", func() { vo(new(string)).Elem().SetFloat(0) })
  4066  	shouldPanic("call of reflect.Value.SetInt on string Value", func() { vo(new(string)).Elem().SetInt(0) })
  4067  	shouldPanic("call of reflect.Value.SetLen on string Value", func() { vo(new(string)).Elem().SetLen(0) })
  4068  	shouldPanic("call of reflect.Value.SetString on int Value", func() { vo(new(int)).Elem().SetString("") })
  4069  	shouldPanic("reflect.Value.SetUint using unaddressable value", func() { vo(0.0).SetUint(0) })
  4070  	shouldPanic("call of reflect.Value.Slice on bool Value", func() { vo(true).Slice(1, 2) })
  4071  	shouldPanic("call of reflect.Value.Slice3 on int Value", func() { vo(0).Slice3(1, 2, 3) })
  4072  	shouldPanic("call of reflect.Value.TryRecv on bool Value", func() { vo(true).TryRecv() })
  4073  	shouldPanic("call of reflect.Value.TrySend on string Value", func() { vo("").TrySend(vo("")) })
  4074  	shouldPanic("call of reflect.Value.Uint on float64 Value", func() { vo(0.0).Uint() })
  4075  }
  4076  
  4077  func shouldPanic(expect string, f func()) {
  4078  	defer func() {
  4079  		r := recover()
  4080  		if r == nil {
  4081  			panic("did not panic")
  4082  		}
  4083  		if expect != "" {
  4084  			var s string
  4085  			switch r := r.(type) {
  4086  			case string:
  4087  				s = r
  4088  			case *ValueError:
  4089  				s = r.Error()
  4090  			default:
  4091  				panic(fmt.Sprintf("panicked with unexpected type %T", r))
  4092  			}
  4093  			if !strings.HasPrefix(s, "reflect") {
  4094  				panic(`panic string does not start with "reflect": ` + s)
  4095  			}
  4096  			if !strings.Contains(s, expect) {
  4097  				panic(`panic string does not contain "` + expect + `": ` + s)
  4098  			}
  4099  		}
  4100  	}()
  4101  	f()
  4102  }
  4103  
  4104  func isNonNil(x any) {
  4105  	if x == nil {
  4106  		panic("nil interface")
  4107  	}
  4108  }
  4109  
  4110  func isValid(v Value) {
  4111  	if !v.IsValid() {
  4112  		panic("zero Value")
  4113  	}
  4114  }
  4115  
  4116  func TestAlias(t *testing.T) {
  4117  	x := string("hello")
  4118  	v := ValueOf(&x).Elem()
  4119  	oldvalue := v.Interface()
  4120  	v.SetString("world")
  4121  	newvalue := v.Interface()
  4122  
  4123  	if oldvalue != "hello" || newvalue != "world" {
  4124  		t.Errorf("aliasing: old=%q new=%q, want hello, world", oldvalue, newvalue)
  4125  	}
  4126  }
  4127  
  4128  var V = ValueOf
  4129  
  4130  func EmptyInterfaceV(x any) Value {
  4131  	return ValueOf(&x).Elem()
  4132  }
  4133  
  4134  func ReaderV(x io.Reader) Value {
  4135  	return ValueOf(&x).Elem()
  4136  }
  4137  
  4138  func ReadWriterV(x io.ReadWriter) Value {
  4139  	return ValueOf(&x).Elem()
  4140  }
  4141  
  4142  type Empty struct{}
  4143  type MyStruct struct {
  4144  	x int `some:"tag"`
  4145  }
  4146  type MyStruct1 struct {
  4147  	x struct {
  4148  		int `some:"bar"`
  4149  	}
  4150  }
  4151  type MyStruct2 struct {
  4152  	x struct {
  4153  		int `some:"foo"`
  4154  	}
  4155  }
  4156  type MyString string
  4157  type MyBytes []byte
  4158  type MyBytesArrayPtr0 *[0]byte
  4159  type MyBytesArrayPtr *[4]byte
  4160  type MyBytesArray0 [0]byte
  4161  type MyBytesArray [4]byte
  4162  type MyRunes []int32
  4163  type MyFunc func()
  4164  type MyByte byte
  4165  
  4166  type IntChan chan int
  4167  type IntChanRecv <-chan int
  4168  type IntChanSend chan<- int
  4169  type BytesChan chan []byte
  4170  type BytesChanRecv <-chan []byte
  4171  type BytesChanSend chan<- []byte
  4172  
  4173  var convertTests = []struct {
  4174  	in  Value
  4175  	out Value
  4176  }{
  4177  	// numbers
  4178  	/*
  4179  		Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go
  4180  
  4181  		package main
  4182  
  4183  		import "fmt"
  4184  
  4185  		var numbers = []string{
  4186  			"int8", "uint8", "int16", "uint16",
  4187  			"int32", "uint32", "int64", "uint64",
  4188  			"int", "uint", "uintptr",
  4189  			"float32", "float64",
  4190  		}
  4191  
  4192  		func main() {
  4193  			// all pairs but in an unusual order,
  4194  			// to emit all the int8, uint8 cases
  4195  			// before n grows too big.
  4196  			n := 1
  4197  			for i, f := range numbers {
  4198  				for _, g := range numbers[i:] {
  4199  					fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n)
  4200  					n++
  4201  					if f != g {
  4202  						fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n)
  4203  						n++
  4204  					}
  4205  				}
  4206  			}
  4207  		}
  4208  	*/
  4209  	{V(int8(1)), V(int8(1))},
  4210  	{V(int8(2)), V(uint8(2))},
  4211  	{V(uint8(3)), V(int8(3))},
  4212  	{V(int8(4)), V(int16(4))},
  4213  	{V(int16(5)), V(int8(5))},
  4214  	{V(int8(6)), V(uint16(6))},
  4215  	{V(uint16(7)), V(int8(7))},
  4216  	{V(int8(8)), V(int32(8))},
  4217  	{V(int32(9)), V(int8(9))},
  4218  	{V(int8(10)), V(uint32(10))},
  4219  	{V(uint32(11)), V(int8(11))},
  4220  	{V(int8(12)), V(int64(12))},
  4221  	{V(int64(13)), V(int8(13))},
  4222  	{V(int8(14)), V(uint64(14))},
  4223  	{V(uint64(15)), V(int8(15))},
  4224  	{V(int8(16)), V(int(16))},
  4225  	{V(int(17)), V(int8(17))},
  4226  	{V(int8(18)), V(uint(18))},
  4227  	{V(uint(19)), V(int8(19))},
  4228  	{V(int8(20)), V(uintptr(20))},
  4229  	{V(uintptr(21)), V(int8(21))},
  4230  	{V(int8(22)), V(float32(22))},
  4231  	{V(float32(23)), V(int8(23))},
  4232  	{V(int8(24)), V(float64(24))},
  4233  	{V(float64(25)), V(int8(25))},
  4234  	{V(uint8(26)), V(uint8(26))},
  4235  	{V(uint8(27)), V(int16(27))},
  4236  	{V(int16(28)), V(uint8(28))},
  4237  	{V(uint8(29)), V(uint16(29))},
  4238  	{V(uint16(30)), V(uint8(30))},
  4239  	{V(uint8(31)), V(int32(31))},
  4240  	{V(int32(32)), V(uint8(32))},
  4241  	{V(uint8(33)), V(uint32(33))},
  4242  	{V(uint32(34)), V(uint8(34))},
  4243  	{V(uint8(35)), V(int64(35))},
  4244  	{V(int64(36)), V(uint8(36))},
  4245  	{V(uint8(37)), V(uint64(37))},
  4246  	{V(uint64(38)), V(uint8(38))},
  4247  	{V(uint8(39)), V(int(39))},
  4248  	{V(int(40)), V(uint8(40))},
  4249  	{V(uint8(41)), V(uint(41))},
  4250  	{V(uint(42)), V(uint8(42))},
  4251  	{V(uint8(43)), V(uintptr(43))},
  4252  	{V(uintptr(44)), V(uint8(44))},
  4253  	{V(uint8(45)), V(float32(45))},
  4254  	{V(float32(46)), V(uint8(46))},
  4255  	{V(uint8(47)), V(float64(47))},
  4256  	{V(float64(48)), V(uint8(48))},
  4257  	{V(int16(49)), V(int16(49))},
  4258  	{V(int16(50)), V(uint16(50))},
  4259  	{V(uint16(51)), V(int16(51))},
  4260  	{V(int16(52)), V(int32(52))},
  4261  	{V(int32(53)), V(int16(53))},
  4262  	{V(int16(54)), V(uint32(54))},
  4263  	{V(uint32(55)), V(int16(55))},
  4264  	{V(int16(56)), V(int64(56))},
  4265  	{V(int64(57)), V(int16(57))},
  4266  	{V(int16(58)), V(uint64(58))},
  4267  	{V(uint64(59)), V(int16(59))},
  4268  	{V(int16(60)), V(int(60))},
  4269  	{V(int(61)), V(int16(61))},
  4270  	{V(int16(62)), V(uint(62))},
  4271  	{V(uint(63)), V(int16(63))},
  4272  	{V(int16(64)), V(uintptr(64))},
  4273  	{V(uintptr(65)), V(int16(65))},
  4274  	{V(int16(66)), V(float32(66))},
  4275  	{V(float32(67)), V(int16(67))},
  4276  	{V(int16(68)), V(float64(68))},
  4277  	{V(float64(69)), V(int16(69))},
  4278  	{V(uint16(70)), V(uint16(70))},
  4279  	{V(uint16(71)), V(int32(71))},
  4280  	{V(int32(72)), V(uint16(72))},
  4281  	{V(uint16(73)), V(uint32(73))},
  4282  	{V(uint32(74)), V(uint16(74))},
  4283  	{V(uint16(75)), V(int64(75))},
  4284  	{V(int64(76)), V(uint16(76))},
  4285  	{V(uint16(77)), V(uint64(77))},
  4286  	{V(uint64(78)), V(uint16(78))},
  4287  	{V(uint16(79)), V(int(79))},
  4288  	{V(int(80)), V(uint16(80))},
  4289  	{V(uint16(81)), V(uint(81))},
  4290  	{V(uint(82)), V(uint16(82))},
  4291  	{V(uint16(83)), V(uintptr(83))},
  4292  	{V(uintptr(84)), V(uint16(84))},
  4293  	{V(uint16(85)), V(float32(85))},
  4294  	{V(float32(86)), V(uint16(86))},
  4295  	{V(uint16(87)), V(float64(87))},
  4296  	{V(float64(88)), V(uint16(88))},
  4297  	{V(int32(89)), V(int32(89))},
  4298  	{V(int32(90)), V(uint32(90))},
  4299  	{V(uint32(91)), V(int32(91))},
  4300  	{V(int32(92)), V(int64(92))},
  4301  	{V(int64(93)), V(int32(93))},
  4302  	{V(int32(94)), V(uint64(94))},
  4303  	{V(uint64(95)), V(int32(95))},
  4304  	{V(int32(96)), V(int(96))},
  4305  	{V(int(97)), V(int32(97))},
  4306  	{V(int32(98)), V(uint(98))},
  4307  	{V(uint(99)), V(int32(99))},
  4308  	{V(int32(100)), V(uintptr(100))},
  4309  	{V(uintptr(101)), V(int32(101))},
  4310  	{V(int32(102)), V(float32(102))},
  4311  	{V(float32(103)), V(int32(103))},
  4312  	{V(int32(104)), V(float64(104))},
  4313  	{V(float64(105)), V(int32(105))},
  4314  	{V(uint32(106)), V(uint32(106))},
  4315  	{V(uint32(107)), V(int64(107))},
  4316  	{V(int64(108)), V(uint32(108))},
  4317  	{V(uint32(109)), V(uint64(109))},
  4318  	{V(uint64(110)), V(uint32(110))},
  4319  	{V(uint32(111)), V(int(111))},
  4320  	{V(int(112)), V(uint32(112))},
  4321  	{V(uint32(113)), V(uint(113))},
  4322  	{V(uint(114)), V(uint32(114))},
  4323  	{V(uint32(115)), V(uintptr(115))},
  4324  	{V(uintptr(116)), V(uint32(116))},
  4325  	{V(uint32(117)), V(float32(117))},
  4326  	{V(float32(118)), V(uint32(118))},
  4327  	{V(uint32(119)), V(float64(119))},
  4328  	{V(float64(120)), V(uint32(120))},
  4329  	{V(int64(121)), V(int64(121))},
  4330  	{V(int64(122)), V(uint64(122))},
  4331  	{V(uint64(123)), V(int64(123))},
  4332  	{V(int64(124)), V(int(124))},
  4333  	{V(int(125)), V(int64(125))},
  4334  	{V(int64(126)), V(uint(126))},
  4335  	{V(uint(127)), V(int64(127))},
  4336  	{V(int64(128)), V(uintptr(128))},
  4337  	{V(uintptr(129)), V(int64(129))},
  4338  	{V(int64(130)), V(float32(130))},
  4339  	{V(float32(131)), V(int64(131))},
  4340  	{V(int64(132)), V(float64(132))},
  4341  	{V(float64(133)), V(int64(133))},
  4342  	{V(uint64(134)), V(uint64(134))},
  4343  	{V(uint64(135)), V(int(135))},
  4344  	{V(int(136)), V(uint64(136))},
  4345  	{V(uint64(137)), V(uint(137))},
  4346  	{V(uint(138)), V(uint64(138))},
  4347  	{V(uint64(139)), V(uintptr(139))},
  4348  	{V(uintptr(140)), V(uint64(140))},
  4349  	{V(uint64(141)), V(float32(141))},
  4350  	{V(float32(142)), V(uint64(142))},
  4351  	{V(uint64(143)), V(float64(143))},
  4352  	{V(float64(144)), V(uint64(144))},
  4353  	{V(int(145)), V(int(145))},
  4354  	{V(int(146)), V(uint(146))},
  4355  	{V(uint(147)), V(int(147))},
  4356  	{V(int(148)), V(uintptr(148))},
  4357  	{V(uintptr(149)), V(int(149))},
  4358  	{V(int(150)), V(float32(150))},
  4359  	{V(float32(151)), V(int(151))},
  4360  	{V(int(152)), V(float64(152))},
  4361  	{V(float64(153)), V(int(153))},
  4362  	{V(uint(154)), V(uint(154))},
  4363  	{V(uint(155)), V(uintptr(155))},
  4364  	{V(uintptr(156)), V(uint(156))},
  4365  	{V(uint(157)), V(float32(157))},
  4366  	{V(float32(158)), V(uint(158))},
  4367  	{V(uint(159)), V(float64(159))},
  4368  	{V(float64(160)), V(uint(160))},
  4369  	{V(uintptr(161)), V(uintptr(161))},
  4370  	{V(uintptr(162)), V(float32(162))},
  4371  	{V(float32(163)), V(uintptr(163))},
  4372  	{V(uintptr(164)), V(float64(164))},
  4373  	{V(float64(165)), V(uintptr(165))},
  4374  	{V(float32(166)), V(float32(166))},
  4375  	{V(float32(167)), V(float64(167))},
  4376  	{V(float64(168)), V(float32(168))},
  4377  	{V(float64(169)), V(float64(169))},
  4378  
  4379  	// truncation
  4380  	{V(float64(1.5)), V(int(1))},
  4381  
  4382  	// complex
  4383  	{V(complex64(1i)), V(complex64(1i))},
  4384  	{V(complex64(2i)), V(complex128(2i))},
  4385  	{V(complex128(3i)), V(complex64(3i))},
  4386  	{V(complex128(4i)), V(complex128(4i))},
  4387  
  4388  	// string
  4389  	{V(string("hello")), V(string("hello"))},
  4390  	{V(string("bytes1")), V([]byte("bytes1"))},
  4391  	{V([]byte("bytes2")), V(string("bytes2"))},
  4392  	{V([]byte("bytes3")), V([]byte("bytes3"))},
  4393  	{V(string("runes♝")), V([]rune("runes♝"))},
  4394  	{V([]rune("runes♕")), V(string("runes♕"))},
  4395  	{V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  4396  	{V(int('a')), V(string("a"))},
  4397  	{V(int8('a')), V(string("a"))},
  4398  	{V(int16('a')), V(string("a"))},
  4399  	{V(int32('a')), V(string("a"))},
  4400  	{V(int64('a')), V(string("a"))},
  4401  	{V(uint('a')), V(string("a"))},
  4402  	{V(uint8('a')), V(string("a"))},
  4403  	{V(uint16('a')), V(string("a"))},
  4404  	{V(uint32('a')), V(string("a"))},
  4405  	{V(uint64('a')), V(string("a"))},
  4406  	{V(uintptr('a')), V(string("a"))},
  4407  	{V(int(-1)), V(string("\uFFFD"))},
  4408  	{V(int8(-2)), V(string("\uFFFD"))},
  4409  	{V(int16(-3)), V(string("\uFFFD"))},
  4410  	{V(int32(-4)), V(string("\uFFFD"))},
  4411  	{V(int64(-5)), V(string("\uFFFD"))},
  4412  	{V(int64(-1 << 32)), V(string("\uFFFD"))},
  4413  	{V(int64(1 << 32)), V(string("\uFFFD"))},
  4414  	{V(uint(0x110001)), V(string("\uFFFD"))},
  4415  	{V(uint32(0x110002)), V(string("\uFFFD"))},
  4416  	{V(uint64(0x110003)), V(string("\uFFFD"))},
  4417  	{V(uint64(1 << 32)), V(string("\uFFFD"))},
  4418  	{V(uintptr(0x110004)), V(string("\uFFFD"))},
  4419  
  4420  	// named string
  4421  	{V(MyString("hello")), V(string("hello"))},
  4422  	{V(string("hello")), V(MyString("hello"))},
  4423  	{V(string("hello")), V(string("hello"))},
  4424  	{V(MyString("hello")), V(MyString("hello"))},
  4425  	{V(MyString("bytes1")), V([]byte("bytes1"))},
  4426  	{V([]byte("bytes2")), V(MyString("bytes2"))},
  4427  	{V([]byte("bytes3")), V([]byte("bytes3"))},
  4428  	{V(MyString("runes♝")), V([]rune("runes♝"))},
  4429  	{V([]rune("runes♕")), V(MyString("runes♕"))},
  4430  	{V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  4431  	{V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
  4432  	{V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  4433  	{V(int('a')), V(MyString("a"))},
  4434  	{V(int8('a')), V(MyString("a"))},
  4435  	{V(int16('a')), V(MyString("a"))},
  4436  	{V(int32('a')), V(MyString("a"))},
  4437  	{V(int64('a')), V(MyString("a"))},
  4438  	{V(uint('a')), V(MyString("a"))},
  4439  	{V(uint8('a')), V(MyString("a"))},
  4440  	{V(uint16('a')), V(MyString("a"))},
  4441  	{V(uint32('a')), V(MyString("a"))},
  4442  	{V(uint64('a')), V(MyString("a"))},
  4443  	{V(uintptr('a')), V(MyString("a"))},
  4444  	{V(int(-1)), V(MyString("\uFFFD"))},
  4445  	{V(int8(-2)), V(MyString("\uFFFD"))},
  4446  	{V(int16(-3)), V(MyString("\uFFFD"))},
  4447  	{V(int32(-4)), V(MyString("\uFFFD"))},
  4448  	{V(int64(-5)), V(MyString("\uFFFD"))},
  4449  	{V(uint(0x110001)), V(MyString("\uFFFD"))},
  4450  	{V(uint32(0x110002)), V(MyString("\uFFFD"))},
  4451  	{V(uint64(0x110003)), V(MyString("\uFFFD"))},
  4452  	{V(uintptr(0x110004)), V(MyString("\uFFFD"))},
  4453  
  4454  	// named []byte
  4455  	{V(string("bytes1")), V(MyBytes("bytes1"))},
  4456  	{V(MyBytes("bytes2")), V(string("bytes2"))},
  4457  	{V(MyBytes("bytes3")), V(MyBytes("bytes3"))},
  4458  	{V(MyString("bytes1")), V(MyBytes("bytes1"))},
  4459  	{V(MyBytes("bytes2")), V(MyString("bytes2"))},
  4460  
  4461  	// named []rune
  4462  	{V(string("runes♝")), V(MyRunes("runes♝"))},
  4463  	{V(MyRunes("runes♕")), V(string("runes♕"))},
  4464  	{V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
  4465  	{V(MyString("runes♝")), V(MyRunes("runes♝"))},
  4466  	{V(MyRunes("runes♕")), V(MyString("runes♕"))},
  4467  
  4468  	// slice to array
  4469  	{V([]byte(nil)), V([0]byte{})},
  4470  	{V([]byte{}), V([0]byte{})},
  4471  	{V([]byte{1}), V([1]byte{1})},
  4472  	{V([]byte{1, 2}), V([2]byte{1, 2})},
  4473  	{V([]byte{1, 2, 3}), V([3]byte{1, 2, 3})},
  4474  	{V(MyBytes([]byte(nil))), V([0]byte{})},
  4475  	{V(MyBytes{}), V([0]byte{})},
  4476  	{V(MyBytes{1}), V([1]byte{1})},
  4477  	{V(MyBytes{1, 2}), V([2]byte{1, 2})},
  4478  	{V(MyBytes{1, 2, 3}), V([3]byte{1, 2, 3})},
  4479  	{V([]byte(nil)), V(MyBytesArray0{})},
  4480  	{V([]byte{}), V(MyBytesArray0([0]byte{}))},
  4481  	{V([]byte{1, 2, 3, 4}), V(MyBytesArray([4]byte{1, 2, 3, 4}))},
  4482  	{V(MyBytes{}), V(MyBytesArray0([0]byte{}))},
  4483  	{V(MyBytes{5, 6, 7, 8}), V(MyBytesArray([4]byte{5, 6, 7, 8}))},
  4484  	{V([]MyByte{}), V([0]MyByte{})},
  4485  	{V([]MyByte{1, 2}), V([2]MyByte{1, 2})},
  4486  
  4487  	// slice to array pointer
  4488  	{V([]byte(nil)), V((*[0]byte)(nil))},
  4489  	{V([]byte{}), V(new([0]byte))},
  4490  	{V([]byte{7}), V(&[1]byte{7})},
  4491  	{V(MyBytes([]byte(nil))), V((*[0]byte)(nil))},
  4492  	{V(MyBytes([]byte{})), V(new([0]byte))},
  4493  	{V(MyBytes([]byte{9})), V(&[1]byte{9})},
  4494  	{V([]byte(nil)), V(MyBytesArrayPtr0(nil))},
  4495  	{V([]byte{}), V(MyBytesArrayPtr0(new([0]byte)))},
  4496  	{V([]byte{1, 2, 3, 4}), V(MyBytesArrayPtr(&[4]byte{1, 2, 3, 4}))},
  4497  	{V(MyBytes([]byte{})), V(MyBytesArrayPtr0(new([0]byte)))},
  4498  	{V(MyBytes([]byte{5, 6, 7, 8})), V(MyBytesArrayPtr(&[4]byte{5, 6, 7, 8}))},
  4499  
  4500  	{V([]byte(nil)), V((*MyBytesArray0)(nil))},
  4501  	{V([]byte{}), V((*MyBytesArray0)(new([0]byte)))},
  4502  	{V([]byte{1, 2, 3, 4}), V(&MyBytesArray{1, 2, 3, 4})},
  4503  	{V(MyBytes([]byte(nil))), V((*MyBytesArray0)(nil))},
  4504  	{V(MyBytes([]byte{})), V((*MyBytesArray0)(new([0]byte)))},
  4505  	{V(MyBytes([]byte{5, 6, 7, 8})), V(&MyBytesArray{5, 6, 7, 8})},
  4506  	{V(new([0]byte)), V(new(MyBytesArray0))},
  4507  	{V(new(MyBytesArray0)), V(new([0]byte))},
  4508  	{V(MyBytesArrayPtr0(nil)), V((*[0]byte)(nil))},
  4509  	{V((*[0]byte)(nil)), V(MyBytesArrayPtr0(nil))},
  4510  
  4511  	// named types and equal underlying types
  4512  	{V(new(int)), V(new(integer))},
  4513  	{V(new(integer)), V(new(int))},
  4514  	{V(Empty{}), V(struct{}{})},
  4515  	{V(new(Empty)), V(new(struct{}))},
  4516  	{V(struct{}{}), V(Empty{})},
  4517  	{V(new(struct{})), V(new(Empty))},
  4518  	{V(Empty{}), V(Empty{})},
  4519  	{V(MyBytes{}), V([]byte{})},
  4520  	{V([]byte{}), V(MyBytes{})},
  4521  	{V((func())(nil)), V(MyFunc(nil))},
  4522  	{V((MyFunc)(nil)), V((func())(nil))},
  4523  
  4524  	// structs with different tags
  4525  	{V(struct {
  4526  		x int `some:"foo"`
  4527  	}{}), V(struct {
  4528  		x int `some:"bar"`
  4529  	}{})},
  4530  
  4531  	{V(struct {
  4532  		x int `some:"bar"`
  4533  	}{}), V(struct {
  4534  		x int `some:"foo"`
  4535  	}{})},
  4536  
  4537  	{V(MyStruct{}), V(struct {
  4538  		x int `some:"foo"`
  4539  	}{})},
  4540  
  4541  	{V(struct {
  4542  		x int `some:"foo"`
  4543  	}{}), V(MyStruct{})},
  4544  
  4545  	{V(MyStruct{}), V(struct {
  4546  		x int `some:"bar"`
  4547  	}{})},
  4548  
  4549  	{V(struct {
  4550  		x int `some:"bar"`
  4551  	}{}), V(MyStruct{})},
  4552  
  4553  	{V(MyStruct1{}), V(MyStruct2{})},
  4554  	{V(MyStruct2{}), V(MyStruct1{})},
  4555  
  4556  	// can convert *byte and *MyByte
  4557  	{V((*byte)(nil)), V((*MyByte)(nil))},
  4558  	{V((*MyByte)(nil)), V((*byte)(nil))},
  4559  
  4560  	// cannot convert mismatched array sizes
  4561  	{V([2]byte{}), V([2]byte{})},
  4562  	{V([3]byte{}), V([3]byte{})},
  4563  	{V(MyBytesArray0{}), V([0]byte{})},
  4564  	{V([0]byte{}), V(MyBytesArray0{})},
  4565  
  4566  	// cannot convert other instances
  4567  	{V((**byte)(nil)), V((**byte)(nil))},
  4568  	{V((**MyByte)(nil)), V((**MyByte)(nil))},
  4569  	{V((chan byte)(nil)), V((chan byte)(nil))},
  4570  	{V((chan MyByte)(nil)), V((chan MyByte)(nil))},
  4571  	{V(([]byte)(nil)), V(([]byte)(nil))},
  4572  	{V(([]MyByte)(nil)), V(([]MyByte)(nil))},
  4573  	{V((map[int]byte)(nil)), V((map[int]byte)(nil))},
  4574  	{V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))},
  4575  	{V((map[byte]int)(nil)), V((map[byte]int)(nil))},
  4576  	{V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))},
  4577  	{V([2]byte{}), V([2]byte{})},
  4578  	{V([2]MyByte{}), V([2]MyByte{})},
  4579  
  4580  	// other
  4581  	{V((***int)(nil)), V((***int)(nil))},
  4582  	{V((***byte)(nil)), V((***byte)(nil))},
  4583  	{V((***int32)(nil)), V((***int32)(nil))},
  4584  	{V((***int64)(nil)), V((***int64)(nil))},
  4585  	{V((chan byte)(nil)), V((chan byte)(nil))},
  4586  	{V((chan MyByte)(nil)), V((chan MyByte)(nil))},
  4587  	{V((map[int]bool)(nil)), V((map[int]bool)(nil))},
  4588  	{V((map[int]byte)(nil)), V((map[int]byte)(nil))},
  4589  	{V((map[uint]bool)(nil)), V((map[uint]bool)(nil))},
  4590  	{V([]uint(nil)), V([]uint(nil))},
  4591  	{V([]int(nil)), V([]int(nil))},
  4592  	{V(new(any)), V(new(any))},
  4593  	{V(new(io.Reader)), V(new(io.Reader))},
  4594  	{V(new(io.Writer)), V(new(io.Writer))},
  4595  
  4596  	// channels
  4597  	{V(IntChan(nil)), V((chan<- int)(nil))},
  4598  	{V(IntChan(nil)), V((<-chan int)(nil))},
  4599  	{V((chan int)(nil)), V(IntChanRecv(nil))},
  4600  	{V((chan int)(nil)), V(IntChanSend(nil))},
  4601  	{V(IntChanRecv(nil)), V((<-chan int)(nil))},
  4602  	{V((<-chan int)(nil)), V(IntChanRecv(nil))},
  4603  	{V(IntChanSend(nil)), V((chan<- int)(nil))},
  4604  	{V((chan<- int)(nil)), V(IntChanSend(nil))},
  4605  	{V(IntChan(nil)), V((chan int)(nil))},
  4606  	{V((chan int)(nil)), V(IntChan(nil))},
  4607  	{V((chan int)(nil)), V((<-chan int)(nil))},
  4608  	{V((chan int)(nil)), V((chan<- int)(nil))},
  4609  	{V(BytesChan(nil)), V((chan<- []byte)(nil))},
  4610  	{V(BytesChan(nil)), V((<-chan []byte)(nil))},
  4611  	{V((chan []byte)(nil)), V(BytesChanRecv(nil))},
  4612  	{V((chan []byte)(nil)), V(BytesChanSend(nil))},
  4613  	{V(BytesChanRecv(nil)), V((<-chan []byte)(nil))},
  4614  	{V((<-chan []byte)(nil)), V(BytesChanRecv(nil))},
  4615  	{V(BytesChanSend(nil)), V((chan<- []byte)(nil))},
  4616  	{V((chan<- []byte)(nil)), V(BytesChanSend(nil))},
  4617  	{V(BytesChan(nil)), V((chan []byte)(nil))},
  4618  	{V((chan []byte)(nil)), V(BytesChan(nil))},
  4619  	{V((chan []byte)(nil)), V((<-chan []byte)(nil))},
  4620  	{V((chan []byte)(nil)), V((chan<- []byte)(nil))},
  4621  
  4622  	// cannot convert other instances (channels)
  4623  	{V(IntChan(nil)), V(IntChan(nil))},
  4624  	{V(IntChanRecv(nil)), V(IntChanRecv(nil))},
  4625  	{V(IntChanSend(nil)), V(IntChanSend(nil))},
  4626  	{V(BytesChan(nil)), V(BytesChan(nil))},
  4627  	{V(BytesChanRecv(nil)), V(BytesChanRecv(nil))},
  4628  	{V(BytesChanSend(nil)), V(BytesChanSend(nil))},
  4629  
  4630  	// interfaces
  4631  	{V(int(1)), EmptyInterfaceV(int(1))},
  4632  	{V(string("hello")), EmptyInterfaceV(string("hello"))},
  4633  	{V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
  4634  	{ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
  4635  	{V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))},
  4636  }
  4637  
  4638  func TestConvert(t *testing.T) {
  4639  	canConvert := map[[2]Type]bool{}
  4640  	all := map[Type]bool{}
  4641  
  4642  	for _, tt := range convertTests {
  4643  		t1 := tt.in.Type()
  4644  		if !t1.ConvertibleTo(t1) {
  4645  			t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1)
  4646  			continue
  4647  		}
  4648  
  4649  		t2 := tt.out.Type()
  4650  		if !t1.ConvertibleTo(t2) {
  4651  			t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2)
  4652  			continue
  4653  		}
  4654  
  4655  		all[t1] = true
  4656  		all[t2] = true
  4657  		canConvert[[2]Type{t1, t2}] = true
  4658  
  4659  		// vout1 represents the in value converted to the in type.
  4660  		v1 := tt.in
  4661  		if !v1.CanConvert(t1) {
  4662  			t.Errorf("ValueOf(%T(%[1]v)).CanConvert(%s) = false, want true", tt.in.Interface(), t1)
  4663  		}
  4664  		vout1 := v1.Convert(t1)
  4665  		out1 := vout1.Interface()
  4666  		if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) {
  4667  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface())
  4668  		}
  4669  
  4670  		// vout2 represents the in value converted to the out type.
  4671  		if !v1.CanConvert(t2) {
  4672  			t.Errorf("ValueOf(%T(%[1]v)).CanConvert(%s) = false, want true", tt.in.Interface(), t2)
  4673  		}
  4674  		vout2 := v1.Convert(t2)
  4675  		out2 := vout2.Interface()
  4676  		if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) {
  4677  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface())
  4678  		}
  4679  		if got, want := vout2.Kind(), vout2.Type().Kind(); got != want {
  4680  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) has internal kind %v want %v", tt.in.Interface(), t1, got, want)
  4681  		}
  4682  
  4683  		// vout3 represents a new value of the out type, set to vout2.  This makes
  4684  		// sure the converted value vout2 is really usable as a regular value.
  4685  		vout3 := New(t2).Elem()
  4686  		vout3.Set(vout2)
  4687  		out3 := vout3.Interface()
  4688  		if vout3.Type() != tt.out.Type() || !DeepEqual(out3, tt.out.Interface()) {
  4689  			t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface())
  4690  		}
  4691  
  4692  		if IsRO(v1) {
  4693  			t.Errorf("table entry %v is RO, should not be", v1)
  4694  		}
  4695  		if IsRO(vout1) {
  4696  			t.Errorf("self-conversion output %v is RO, should not be", vout1)
  4697  		}
  4698  		if IsRO(vout2) {
  4699  			t.Errorf("conversion output %v is RO, should not be", vout2)
  4700  		}
  4701  		if IsRO(vout3) {
  4702  			t.Errorf("set(conversion output) %v is RO, should not be", vout3)
  4703  		}
  4704  		if !IsRO(MakeRO(v1).Convert(t1)) {
  4705  			t.Errorf("RO self-conversion output %v is not RO, should be", v1)
  4706  		}
  4707  		if !IsRO(MakeRO(v1).Convert(t2)) {
  4708  			t.Errorf("RO conversion output %v is not RO, should be", v1)
  4709  		}
  4710  	}
  4711  
  4712  	// Assume that of all the types we saw during the tests,
  4713  	// if there wasn't an explicit entry for a conversion between
  4714  	// a pair of types, then it's not to be allowed. This checks for
  4715  	// things like 'int64' converting to '*int'.
  4716  	for t1 := range all {
  4717  		for t2 := range all {
  4718  			expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0
  4719  			if ok := t1.ConvertibleTo(t2); ok != expectOK {
  4720  				t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK)
  4721  			}
  4722  		}
  4723  	}
  4724  }
  4725  
  4726  func TestConvertPanic(t *testing.T) {
  4727  	s := make([]byte, 4)
  4728  	p := new([8]byte)
  4729  	v := ValueOf(s)
  4730  	pt := TypeOf(p)
  4731  	if !v.Type().ConvertibleTo(pt) {
  4732  		t.Errorf("[]byte should be convertible to *[8]byte")
  4733  	}
  4734  	if v.CanConvert(pt) {
  4735  		t.Errorf("slice with length 4 should not be convertible to *[8]byte")
  4736  	}
  4737  	shouldPanic("reflect: cannot convert slice with length 4 to pointer to array with length 8", func() {
  4738  		_ = v.Convert(pt)
  4739  	})
  4740  
  4741  	if v.CanConvert(pt.Elem()) {
  4742  		t.Errorf("slice with length 4 should not be convertible to [8]byte")
  4743  	}
  4744  	shouldPanic("reflect: cannot convert slice with length 4 to array with length 8", func() {
  4745  		_ = v.Convert(pt.Elem())
  4746  	})
  4747  }
  4748  
  4749  func TestConvertSlice2Array(t *testing.T) {
  4750  	s := make([]int, 4)
  4751  	p := [4]int{}
  4752  	pt := TypeOf(p)
  4753  	ov := ValueOf(s)
  4754  	v := ov.Convert(pt)
  4755  	// Converting a slice to non-empty array needs to return
  4756  	// a non-addressable copy of the original memory.
  4757  	if v.CanAddr() {
  4758  		t.Fatalf("convert slice to non-empty array returns an addressable copy array")
  4759  	}
  4760  	for i := range s {
  4761  		ov.Index(i).Set(ValueOf(i + 1))
  4762  	}
  4763  	for i := range s {
  4764  		if v.Index(i).Int() != 0 {
  4765  			t.Fatalf("slice (%v) mutation visible in converted result (%v)", ov, v)
  4766  		}
  4767  	}
  4768  }
  4769  
  4770  var gFloat32 float32
  4771  
  4772  const snan uint32 = 0x7f800001
  4773  
  4774  func TestConvertNaNs(t *testing.T) {
  4775  	// Test to see if a store followed by a load of a signaling NaN
  4776  	// maintains the signaling bit. (This used to fail on the 387 port.)
  4777  	gFloat32 = math.Float32frombits(snan)
  4778  	runtime.Gosched() // make sure we don't optimize the store/load away
  4779  	if got := math.Float32bits(gFloat32); got != snan {
  4780  		t.Errorf("store/load of sNaN not faithful, got %x want %x", got, snan)
  4781  	}
  4782  	// Test reflect's conversion between float32s. See issue 36400.
  4783  	type myFloat32 float32
  4784  	x := V(myFloat32(math.Float32frombits(snan)))
  4785  	y := x.Convert(TypeOf(float32(0)))
  4786  	z := y.Interface().(float32)
  4787  	if got := math.Float32bits(z); got != snan {
  4788  		t.Errorf("signaling nan conversion got %x, want %x", got, snan)
  4789  	}
  4790  }
  4791  
  4792  type ComparableStruct struct {
  4793  	X int
  4794  }
  4795  
  4796  type NonComparableStruct struct {
  4797  	X int
  4798  	Y map[string]int
  4799  }
  4800  
  4801  var comparableTests = []struct {
  4802  	typ Type
  4803  	ok  bool
  4804  }{
  4805  	{TypeOf(1), true},
  4806  	{TypeOf("hello"), true},
  4807  	{TypeOf(new(byte)), true},
  4808  	{TypeOf((func())(nil)), false},
  4809  	{TypeOf([]byte{}), false},
  4810  	{TypeOf(map[string]int{}), false},
  4811  	{TypeOf(make(chan int)), true},
  4812  	{TypeOf(1.5), true},
  4813  	{TypeOf(false), true},
  4814  	{TypeOf(1i), true},
  4815  	{TypeOf(ComparableStruct{}), true},
  4816  	{TypeOf(NonComparableStruct{}), false},
  4817  	{TypeOf([10]map[string]int{}), false},
  4818  	{TypeOf([10]string{}), true},
  4819  	{TypeOf(new(any)).Elem(), true},
  4820  }
  4821  
  4822  func TestComparable(t *testing.T) {
  4823  	for _, tt := range comparableTests {
  4824  		if ok := tt.typ.Comparable(); ok != tt.ok {
  4825  			t.Errorf("TypeOf(%v).Comparable() = %v, want %v", tt.typ, ok, tt.ok)
  4826  		}
  4827  	}
  4828  }
  4829  
  4830  func TestValueOverflow(t *testing.T) {
  4831  	if ovf := V(float64(0)).OverflowFloat(1e300); ovf {
  4832  		t.Errorf("%v wrongly overflows float64", 1e300)
  4833  	}
  4834  
  4835  	maxFloat32 := float64((1<<24 - 1) << (127 - 23))
  4836  	if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf {
  4837  		t.Errorf("%v wrongly overflows float32", maxFloat32)
  4838  	}
  4839  	ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52))
  4840  	if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf {
  4841  		t.Errorf("%v should overflow float32", ovfFloat32)
  4842  	}
  4843  	if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf {
  4844  		t.Errorf("%v should overflow float32", -ovfFloat32)
  4845  	}
  4846  
  4847  	maxInt32 := int64(0x7fffffff)
  4848  	if ovf := V(int32(0)).OverflowInt(maxInt32); ovf {
  4849  		t.Errorf("%v wrongly overflows int32", maxInt32)
  4850  	}
  4851  	if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf {
  4852  		t.Errorf("%v wrongly overflows int32", -int64(1)<<31)
  4853  	}
  4854  	ovfInt32 := int64(1 << 31)
  4855  	if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf {
  4856  		t.Errorf("%v should overflow int32", ovfInt32)
  4857  	}
  4858  
  4859  	maxUint32 := uint64(0xffffffff)
  4860  	if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf {
  4861  		t.Errorf("%v wrongly overflows uint32", maxUint32)
  4862  	}
  4863  	ovfUint32 := uint64(1 << 32)
  4864  	if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf {
  4865  		t.Errorf("%v should overflow uint32", ovfUint32)
  4866  	}
  4867  }
  4868  
  4869  func TestTypeOverflow(t *testing.T) {
  4870  	if ovf := TypeFor[float64]().OverflowFloat(1e300); ovf {
  4871  		t.Errorf("%v wrongly overflows float64", 1e300)
  4872  	}
  4873  
  4874  	maxFloat32 := float64((1<<24 - 1) << (127 - 23))
  4875  	if ovf := TypeFor[float32]().OverflowFloat(maxFloat32); ovf {
  4876  		t.Errorf("%v wrongly overflows float32", maxFloat32)
  4877  	}
  4878  	ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52))
  4879  	if ovf := TypeFor[float32]().OverflowFloat(ovfFloat32); !ovf {
  4880  		t.Errorf("%v should overflow float32", ovfFloat32)
  4881  	}
  4882  	if ovf := TypeFor[float32]().OverflowFloat(-ovfFloat32); !ovf {
  4883  		t.Errorf("%v should overflow float32", -ovfFloat32)
  4884  	}
  4885  
  4886  	maxInt32 := int64(0x7fffffff)
  4887  	if ovf := TypeFor[int32]().OverflowInt(maxInt32); ovf {
  4888  		t.Errorf("%v wrongly overflows int32", maxInt32)
  4889  	}
  4890  	if ovf := TypeFor[int32]().OverflowInt(-1 << 31); ovf {
  4891  		t.Errorf("%v wrongly overflows int32", -int64(1)<<31)
  4892  	}
  4893  	ovfInt32 := int64(1 << 31)
  4894  	if ovf := TypeFor[int32]().OverflowInt(ovfInt32); !ovf {
  4895  		t.Errorf("%v should overflow int32", ovfInt32)
  4896  	}
  4897  
  4898  	maxUint32 := uint64(0xffffffff)
  4899  	if ovf := TypeFor[uint32]().OverflowUint(maxUint32); ovf {
  4900  		t.Errorf("%v wrongly overflows uint32", maxUint32)
  4901  	}
  4902  	ovfUint32 := uint64(1 << 32)
  4903  	if ovf := TypeFor[uint32]().OverflowUint(ovfUint32); !ovf {
  4904  		t.Errorf("%v should overflow uint32", ovfUint32)
  4905  	}
  4906  }
  4907  
  4908  func checkSameType(t *testing.T, x Type, y any) {
  4909  	if x != TypeOf(y) || TypeOf(Zero(x).Interface()) != TypeOf(y) {
  4910  		t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y))
  4911  	}
  4912  }
  4913  
  4914  func TestArrayOf(t *testing.T) {
  4915  	// check construction and use of type not in binary
  4916  	tests := []struct {
  4917  		n          int
  4918  		value      func(i int) any
  4919  		comparable bool
  4920  		want       string
  4921  	}{
  4922  		{
  4923  			n:          0,
  4924  			value:      func(i int) any { type Tint int; return Tint(i) },
  4925  			comparable: true,
  4926  			want:       "[]",
  4927  		},
  4928  		{
  4929  			n:          10,
  4930  			value:      func(i int) any { type Tint int; return Tint(i) },
  4931  			comparable: true,
  4932  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  4933  		},
  4934  		{
  4935  			n:          10,
  4936  			value:      func(i int) any { type Tfloat float64; return Tfloat(i) },
  4937  			comparable: true,
  4938  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  4939  		},
  4940  		{
  4941  			n:          10,
  4942  			value:      func(i int) any { type Tstring string; return Tstring(strconv.Itoa(i)) },
  4943  			comparable: true,
  4944  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  4945  		},
  4946  		{
  4947  			n:          10,
  4948  			value:      func(i int) any { type Tstruct struct{ V int }; return Tstruct{i} },
  4949  			comparable: true,
  4950  			want:       "[{0} {1} {2} {3} {4} {5} {6} {7} {8} {9}]",
  4951  		},
  4952  		{
  4953  			n:          10,
  4954  			value:      func(i int) any { type Tint int; return []Tint{Tint(i)} },
  4955  			comparable: false,
  4956  			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
  4957  		},
  4958  		{
  4959  			n:          10,
  4960  			value:      func(i int) any { type Tint int; return [1]Tint{Tint(i)} },
  4961  			comparable: true,
  4962  			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
  4963  		},
  4964  		{
  4965  			n:          10,
  4966  			value:      func(i int) any { type Tstruct struct{ V [1]int }; return Tstruct{[1]int{i}} },
  4967  			comparable: true,
  4968  			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
  4969  		},
  4970  		{
  4971  			n:          10,
  4972  			value:      func(i int) any { type Tstruct struct{ V []int }; return Tstruct{[]int{i}} },
  4973  			comparable: false,
  4974  			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
  4975  		},
  4976  		{
  4977  			n:          10,
  4978  			value:      func(i int) any { type TstructUV struct{ U, V int }; return TstructUV{i, i} },
  4979  			comparable: true,
  4980  			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
  4981  		},
  4982  		{
  4983  			n: 10,
  4984  			value: func(i int) any {
  4985  				type TstructUV struct {
  4986  					U int
  4987  					V float64
  4988  				}
  4989  				return TstructUV{i, float64(i)}
  4990  			},
  4991  			comparable: true,
  4992  			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
  4993  		},
  4994  	}
  4995  
  4996  	for _, table := range tests {
  4997  		at := ArrayOf(table.n, TypeOf(table.value(0)))
  4998  		v := New(at).Elem()
  4999  		vok := New(at).Elem()
  5000  		vnot := New(at).Elem()
  5001  		for i := 0; i < v.Len(); i++ {
  5002  			v.Index(i).Set(ValueOf(table.value(i)))
  5003  			vok.Index(i).Set(ValueOf(table.value(i)))
  5004  			j := i
  5005  			if i+1 == v.Len() {
  5006  				j = i + 1
  5007  			}
  5008  			vnot.Index(i).Set(ValueOf(table.value(j))) // make it differ only by last element
  5009  		}
  5010  		s := fmt.Sprint(v.Interface())
  5011  		if s != table.want {
  5012  			t.Errorf("constructed array = %s, want %s", s, table.want)
  5013  		}
  5014  
  5015  		if table.comparable != at.Comparable() {
  5016  			t.Errorf("constructed array (%#v) is comparable=%v, want=%v", v.Interface(), at.Comparable(), table.comparable)
  5017  		}
  5018  		if table.comparable {
  5019  			if table.n > 0 {
  5020  				if DeepEqual(vnot.Interface(), v.Interface()) {
  5021  					t.Errorf(
  5022  						"arrays (%#v) compare ok (but should not)",
  5023  						v.Interface(),
  5024  					)
  5025  				}
  5026  			}
  5027  			if !DeepEqual(vok.Interface(), v.Interface()) {
  5028  				t.Errorf(
  5029  					"arrays (%#v) compare NOT-ok (but should)",
  5030  					v.Interface(),
  5031  				)
  5032  			}
  5033  		}
  5034  	}
  5035  
  5036  	// check that type already in binary is found
  5037  	type T int
  5038  	checkSameType(t, ArrayOf(5, TypeOf(T(1))), [5]T{})
  5039  }
  5040  
  5041  func TestArrayOfGC(t *testing.T) {
  5042  	type T *uintptr
  5043  	tt := TypeOf(T(nil))
  5044  	const n = 100
  5045  	var x []any
  5046  	for i := 0; i < n; i++ {
  5047  		v := New(ArrayOf(n, tt)).Elem()
  5048  		for j := 0; j < v.Len(); j++ {
  5049  			p := new(uintptr)
  5050  			*p = uintptr(i*n + j)
  5051  			v.Index(j).Set(ValueOf(p).Convert(tt))
  5052  		}
  5053  		x = append(x, v.Interface())
  5054  	}
  5055  	runtime.GC()
  5056  
  5057  	for i, xi := range x {
  5058  		v := ValueOf(xi)
  5059  		for j := 0; j < v.Len(); j++ {
  5060  			k := v.Index(j).Elem().Interface()
  5061  			if k != uintptr(i*n+j) {
  5062  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  5063  			}
  5064  		}
  5065  	}
  5066  }
  5067  
  5068  func TestArrayOfAlg(t *testing.T) {
  5069  	at := ArrayOf(6, TypeOf(byte(0)))
  5070  	v1 := New(at).Elem()
  5071  	v2 := New(at).Elem()
  5072  	if v1.Interface() != v1.Interface() {
  5073  		t.Errorf("constructed array %v not equal to itself", v1.Interface())
  5074  	}
  5075  	v1.Index(5).Set(ValueOf(byte(1)))
  5076  	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
  5077  		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
  5078  	}
  5079  
  5080  	at = ArrayOf(6, TypeOf([]int(nil)))
  5081  	v1 = New(at).Elem()
  5082  	shouldPanic("", func() { _ = v1.Interface() == v1.Interface() })
  5083  }
  5084  
  5085  func TestArrayOfGenericAlg(t *testing.T) {
  5086  	at1 := ArrayOf(5, TypeOf(string("")))
  5087  	at := ArrayOf(6, at1)
  5088  	v1 := New(at).Elem()
  5089  	v2 := New(at).Elem()
  5090  	if v1.Interface() != v1.Interface() {
  5091  		t.Errorf("constructed array %v not equal to itself", v1.Interface())
  5092  	}
  5093  
  5094  	v1.Index(0).Index(0).Set(ValueOf("abc"))
  5095  	v2.Index(0).Index(0).Set(ValueOf("efg"))
  5096  	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
  5097  		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
  5098  	}
  5099  
  5100  	v1.Index(0).Index(0).Set(ValueOf("abc"))
  5101  	v2.Index(0).Index(0).Set(ValueOf((v1.Index(0).Index(0).String() + " ")[:3]))
  5102  	if i1, i2 := v1.Interface(), v2.Interface(); i1 != i2 {
  5103  		t.Errorf("constructed arrays %v and %v should be equal", i1, i2)
  5104  	}
  5105  
  5106  	// Test hash
  5107  	m := MakeMap(MapOf(at, TypeOf(int(0))))
  5108  	m.SetMapIndex(v1, ValueOf(1))
  5109  	if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  5110  		t.Errorf("constructed arrays %v and %v have different hashes", i1, i2)
  5111  	}
  5112  }
  5113  
  5114  func TestArrayOfDirectIface(t *testing.T) {
  5115  	{
  5116  		type T [1]*byte
  5117  		i1 := Zero(TypeOf(T{})).Interface()
  5118  		v1 := ValueOf(&i1).Elem()
  5119  		p1 := v1.InterfaceData()[1]
  5120  
  5121  		i2 := Zero(ArrayOf(1, PointerTo(TypeOf(int8(0))))).Interface()
  5122  		v2 := ValueOf(&i2).Elem()
  5123  		p2 := v2.InterfaceData()[1]
  5124  
  5125  		if p1 != 0 {
  5126  			t.Errorf("got p1=%v. want=%v", p1, nil)
  5127  		}
  5128  
  5129  		if p2 != 0 {
  5130  			t.Errorf("got p2=%v. want=%v", p2, nil)
  5131  		}
  5132  	}
  5133  	{
  5134  		type T [0]*byte
  5135  		i1 := Zero(TypeOf(T{})).Interface()
  5136  		v1 := ValueOf(&i1).Elem()
  5137  		p1 := v1.InterfaceData()[1]
  5138  
  5139  		i2 := Zero(ArrayOf(0, PointerTo(TypeOf(int8(0))))).Interface()
  5140  		v2 := ValueOf(&i2).Elem()
  5141  		p2 := v2.InterfaceData()[1]
  5142  
  5143  		if p1 == 0 {
  5144  			t.Errorf("got p1=%v. want=not-%v", p1, nil)
  5145  		}
  5146  
  5147  		if p2 == 0 {
  5148  			t.Errorf("got p2=%v. want=not-%v", p2, nil)
  5149  		}
  5150  	}
  5151  }
  5152  
  5153  // Ensure passing in negative lengths panics.
  5154  // See https://golang.org/issue/43603
  5155  func TestArrayOfPanicOnNegativeLength(t *testing.T) {
  5156  	shouldPanic("reflect: negative length passed to ArrayOf", func() {
  5157  		ArrayOf(-1, TypeOf(byte(0)))
  5158  	})
  5159  }
  5160  
  5161  func TestSliceOf(t *testing.T) {
  5162  	// check construction and use of type not in binary
  5163  	type T int
  5164  	st := SliceOf(TypeOf(T(1)))
  5165  	if got, want := st.String(), "[]reflect_test.T"; got != want {
  5166  		t.Errorf("SliceOf(T(1)).String()=%q, want %q", got, want)
  5167  	}
  5168  	v := MakeSlice(st, 10, 10)
  5169  	runtime.GC()
  5170  	for i := 0; i < v.Len(); i++ {
  5171  		v.Index(i).Set(ValueOf(T(i)))
  5172  		runtime.GC()
  5173  	}
  5174  	s := fmt.Sprint(v.Interface())
  5175  	want := "[0 1 2 3 4 5 6 7 8 9]"
  5176  	if s != want {
  5177  		t.Errorf("constructed slice = %s, want %s", s, want)
  5178  	}
  5179  
  5180  	// check that type already in binary is found
  5181  	type T1 int
  5182  	checkSameType(t, SliceOf(TypeOf(T1(1))), []T1{})
  5183  }
  5184  
  5185  func TestSliceOverflow(t *testing.T) {
  5186  	// check that MakeSlice panics when size of slice overflows uint
  5187  	const S = 1e6
  5188  	s := uint(S)
  5189  	l := (1<<(unsafe.Sizeof((*byte)(nil))*8)-1)/s + 1
  5190  	if l*s >= s {
  5191  		t.Fatal("slice size does not overflow")
  5192  	}
  5193  	var x [S]byte
  5194  	st := SliceOf(TypeOf(x))
  5195  	defer func() {
  5196  		err := recover()
  5197  		if err == nil {
  5198  			t.Fatal("slice overflow does not panic")
  5199  		}
  5200  	}()
  5201  	MakeSlice(st, int(l), int(l))
  5202  }
  5203  
  5204  func TestSliceOfGC(t *testing.T) {
  5205  	type T *uintptr
  5206  	tt := TypeOf(T(nil))
  5207  	st := SliceOf(tt)
  5208  	const n = 100
  5209  	var x []any
  5210  	for i := 0; i < n; i++ {
  5211  		v := MakeSlice(st, n, n)
  5212  		for j := 0; j < v.Len(); j++ {
  5213  			p := new(uintptr)
  5214  			*p = uintptr(i*n + j)
  5215  			v.Index(j).Set(ValueOf(p).Convert(tt))
  5216  		}
  5217  		x = append(x, v.Interface())
  5218  	}
  5219  	runtime.GC()
  5220  
  5221  	for i, xi := range x {
  5222  		v := ValueOf(xi)
  5223  		for j := 0; j < v.Len(); j++ {
  5224  			k := v.Index(j).Elem().Interface()
  5225  			if k != uintptr(i*n+j) {
  5226  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  5227  			}
  5228  		}
  5229  	}
  5230  }
  5231  
  5232  func TestStructOfFieldName(t *testing.T) {
  5233  	// invalid field name "1nvalid"
  5234  	shouldPanic("has invalid name", func() {
  5235  		StructOf([]StructField{
  5236  			{Name: "Valid", Type: TypeOf("")},
  5237  			{Name: "1nvalid", Type: TypeOf("")},
  5238  		})
  5239  	})
  5240  
  5241  	// invalid field name "+"
  5242  	shouldPanic("has invalid name", func() {
  5243  		StructOf([]StructField{
  5244  			{Name: "Val1d", Type: TypeOf("")},
  5245  			{Name: "+", Type: TypeOf("")},
  5246  		})
  5247  	})
  5248  
  5249  	// no field name
  5250  	shouldPanic("has no name", func() {
  5251  		StructOf([]StructField{
  5252  			{Name: "", Type: TypeOf("")},
  5253  		})
  5254  	})
  5255  
  5256  	// verify creation of a struct with valid struct fields
  5257  	validFields := []StructField{
  5258  		{
  5259  			Name: "φ",
  5260  			Type: TypeOf(""),
  5261  		},
  5262  		{
  5263  			Name: "ValidName",
  5264  			Type: TypeOf(""),
  5265  		},
  5266  		{
  5267  			Name: "Val1dNam5",
  5268  			Type: TypeOf(""),
  5269  		},
  5270  	}
  5271  
  5272  	validStruct := StructOf(validFields)
  5273  
  5274  	const structStr = `struct { φ string; ValidName string; Val1dNam5 string }`
  5275  	if got, want := validStruct.String(), structStr; got != want {
  5276  		t.Errorf("StructOf(validFields).String()=%q, want %q", got, want)
  5277  	}
  5278  }
  5279  
  5280  func TestStructOf(t *testing.T) {
  5281  	// check construction and use of type not in binary
  5282  	fields := []StructField{
  5283  		{
  5284  			Name: "S",
  5285  			Tag:  "s",
  5286  			Type: TypeOf(""),
  5287  		},
  5288  		{
  5289  			Name: "X",
  5290  			Tag:  "x",
  5291  			Type: TypeOf(byte(0)),
  5292  		},
  5293  		{
  5294  			Name: "Y",
  5295  			Type: TypeOf(uint64(0)),
  5296  		},
  5297  		{
  5298  			Name: "Z",
  5299  			Type: TypeOf([3]uint16{}),
  5300  		},
  5301  	}
  5302  
  5303  	st := StructOf(fields)
  5304  	v := New(st).Elem()
  5305  	runtime.GC()
  5306  	v.FieldByName("X").Set(ValueOf(byte(2)))
  5307  	v.FieldByIndex([]int{1}).Set(ValueOf(byte(1)))
  5308  	runtime.GC()
  5309  
  5310  	s := fmt.Sprint(v.Interface())
  5311  	want := `{ 1 0 [0 0 0]}`
  5312  	if s != want {
  5313  		t.Errorf("constructed struct = %s, want %s", s, want)
  5314  	}
  5315  	const stStr = `struct { S string "s"; X uint8 "x"; Y uint64; Z [3]uint16 }`
  5316  	if got, want := st.String(), stStr; got != want {
  5317  		t.Errorf("StructOf(fields).String()=%q, want %q", got, want)
  5318  	}
  5319  
  5320  	// check the size, alignment and field offsets
  5321  	stt := TypeOf(struct {
  5322  		String string
  5323  		X      byte
  5324  		Y      uint64
  5325  		Z      [3]uint16
  5326  	}{})
  5327  	if st.Size() != stt.Size() {
  5328  		t.Errorf("constructed struct size = %v, want %v", st.Size(), stt.Size())
  5329  	}
  5330  	if st.Align() != stt.Align() {
  5331  		t.Errorf("constructed struct align = %v, want %v", st.Align(), stt.Align())
  5332  	}
  5333  	if st.FieldAlign() != stt.FieldAlign() {
  5334  		t.Errorf("constructed struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign())
  5335  	}
  5336  	for i := 0; i < st.NumField(); i++ {
  5337  		o1 := st.Field(i).Offset
  5338  		o2 := stt.Field(i).Offset
  5339  		if o1 != o2 {
  5340  			t.Errorf("constructed struct field %v offset = %v, want %v", i, o1, o2)
  5341  		}
  5342  	}
  5343  
  5344  	// Check size and alignment with a trailing zero-sized field.
  5345  	st = StructOf([]StructField{
  5346  		{
  5347  			Name: "F1",
  5348  			Type: TypeOf(byte(0)),
  5349  		},
  5350  		{
  5351  			Name: "F2",
  5352  			Type: TypeOf([0]*byte{}),
  5353  		},
  5354  	})
  5355  	stt = TypeOf(struct {
  5356  		G1 byte
  5357  		G2 [0]*byte
  5358  	}{})
  5359  	if st.Size() != stt.Size() {
  5360  		t.Errorf("constructed zero-padded struct size = %v, want %v", st.Size(), stt.Size())
  5361  	}
  5362  	if st.Align() != stt.Align() {
  5363  		t.Errorf("constructed zero-padded struct align = %v, want %v", st.Align(), stt.Align())
  5364  	}
  5365  	if st.FieldAlign() != stt.FieldAlign() {
  5366  		t.Errorf("constructed zero-padded struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign())
  5367  	}
  5368  	for i := 0; i < st.NumField(); i++ {
  5369  		o1 := st.Field(i).Offset
  5370  		o2 := stt.Field(i).Offset
  5371  		if o1 != o2 {
  5372  			t.Errorf("constructed zero-padded struct field %v offset = %v, want %v", i, o1, o2)
  5373  		}
  5374  	}
  5375  
  5376  	// check duplicate names
  5377  	shouldPanic("duplicate field", func() {
  5378  		StructOf([]StructField{
  5379  			{Name: "string", PkgPath: "p", Type: TypeOf("")},
  5380  			{Name: "string", PkgPath: "p", Type: TypeOf("")},
  5381  		})
  5382  	})
  5383  	shouldPanic("has no name", func() {
  5384  		StructOf([]StructField{
  5385  			{Type: TypeOf("")},
  5386  			{Name: "string", PkgPath: "p", Type: TypeOf("")},
  5387  		})
  5388  	})
  5389  	shouldPanic("has no name", func() {
  5390  		StructOf([]StructField{
  5391  			{Type: TypeOf("")},
  5392  			{Type: TypeOf("")},
  5393  		})
  5394  	})
  5395  	// check that type already in binary is found
  5396  	checkSameType(t, StructOf(fields[2:3]), struct{ Y uint64 }{})
  5397  
  5398  	// gccgo used to fail this test.
  5399  	type structFieldType any
  5400  	checkSameType(t,
  5401  		StructOf([]StructField{
  5402  			{
  5403  				Name: "F",
  5404  				Type: TypeOf((*structFieldType)(nil)).Elem(),
  5405  			},
  5406  		}),
  5407  		struct{ F structFieldType }{})
  5408  }
  5409  
  5410  func TestStructOfExportRules(t *testing.T) {
  5411  	type S1 struct{}
  5412  	type s2 struct{}
  5413  	type ΦType struct{}
  5414  	type φType struct{}
  5415  
  5416  	testPanic := func(i int, mustPanic bool, f func()) {
  5417  		defer func() {
  5418  			err := recover()
  5419  			if err == nil && mustPanic {
  5420  				t.Errorf("test-%d did not panic", i)
  5421  			}
  5422  			if err != nil && !mustPanic {
  5423  				t.Errorf("test-%d panicked: %v\n", i, err)
  5424  			}
  5425  		}()
  5426  		f()
  5427  	}
  5428  
  5429  	tests := []struct {
  5430  		field     StructField
  5431  		mustPanic bool
  5432  		exported  bool
  5433  	}{
  5434  		{
  5435  			field:    StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{})},
  5436  			exported: true,
  5437  		},
  5438  		{
  5439  			field:    StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil))},
  5440  			exported: true,
  5441  		},
  5442  		{
  5443  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{})},
  5444  			mustPanic: true,
  5445  		},
  5446  		{
  5447  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil))},
  5448  			mustPanic: true,
  5449  		},
  5450  		{
  5451  			field:     StructField{Name: "Name", Type: nil, PkgPath: ""},
  5452  			mustPanic: true,
  5453  		},
  5454  		{
  5455  			field:     StructField{Name: "", Type: TypeOf(S1{}), PkgPath: ""},
  5456  			mustPanic: true,
  5457  		},
  5458  		{
  5459  			field:     StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{}), PkgPath: "other/pkg"},
  5460  			mustPanic: true,
  5461  		},
  5462  		{
  5463  			field:     StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"},
  5464  			mustPanic: true,
  5465  		},
  5466  		{
  5467  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{}), PkgPath: "other/pkg"},
  5468  			mustPanic: true,
  5469  		},
  5470  		{
  5471  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"},
  5472  			mustPanic: true,
  5473  		},
  5474  		{
  5475  			field: StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"},
  5476  		},
  5477  		{
  5478  			field: StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"},
  5479  		},
  5480  		{
  5481  			field:    StructField{Name: "S", Type: TypeOf(S1{})},
  5482  			exported: true,
  5483  		},
  5484  		{
  5485  			field:    StructField{Name: "S", Type: TypeOf((*S1)(nil))},
  5486  			exported: true,
  5487  		},
  5488  		{
  5489  			field:    StructField{Name: "S", Type: TypeOf(s2{})},
  5490  			exported: true,
  5491  		},
  5492  		{
  5493  			field:    StructField{Name: "S", Type: TypeOf((*s2)(nil))},
  5494  			exported: true,
  5495  		},
  5496  		{
  5497  			field:     StructField{Name: "s", Type: TypeOf(S1{})},
  5498  			mustPanic: true,
  5499  		},
  5500  		{
  5501  			field:     StructField{Name: "s", Type: TypeOf((*S1)(nil))},
  5502  			mustPanic: true,
  5503  		},
  5504  		{
  5505  			field:     StructField{Name: "s", Type: TypeOf(s2{})},
  5506  			mustPanic: true,
  5507  		},
  5508  		{
  5509  			field:     StructField{Name: "s", Type: TypeOf((*s2)(nil))},
  5510  			mustPanic: true,
  5511  		},
  5512  		{
  5513  			field: StructField{Name: "s", Type: TypeOf(S1{}), PkgPath: "other/pkg"},
  5514  		},
  5515  		{
  5516  			field: StructField{Name: "s", Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"},
  5517  		},
  5518  		{
  5519  			field: StructField{Name: "s", Type: TypeOf(s2{}), PkgPath: "other/pkg"},
  5520  		},
  5521  		{
  5522  			field: StructField{Name: "s", Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"},
  5523  		},
  5524  		{
  5525  			field:     StructField{Name: "", Type: TypeOf(ΦType{})},
  5526  			mustPanic: true,
  5527  		},
  5528  		{
  5529  			field:     StructField{Name: "", Type: TypeOf(φType{})},
  5530  			mustPanic: true,
  5531  		},
  5532  		{
  5533  			field:    StructField{Name: "Φ", Type: TypeOf(0)},
  5534  			exported: true,
  5535  		},
  5536  		{
  5537  			field:    StructField{Name: "φ", Type: TypeOf(0)},
  5538  			exported: false,
  5539  		},
  5540  	}
  5541  
  5542  	for i, test := range tests {
  5543  		testPanic(i, test.mustPanic, func() {
  5544  			typ := StructOf([]StructField{test.field})
  5545  			if typ == nil {
  5546  				t.Errorf("test-%d: error creating struct type", i)
  5547  				return
  5548  			}
  5549  			field := typ.Field(0)
  5550  			n := field.Name
  5551  			if n == "" {
  5552  				panic("field.Name must not be empty")
  5553  			}
  5554  			exported := token.IsExported(n)
  5555  			if exported != test.exported {
  5556  				t.Errorf("test-%d: got exported=%v want exported=%v", i, exported, test.exported)
  5557  			}
  5558  			if field.PkgPath != test.field.PkgPath {
  5559  				t.Errorf("test-%d: got PkgPath=%q want pkgPath=%q", i, field.PkgPath, test.field.PkgPath)
  5560  			}
  5561  		})
  5562  	}
  5563  }
  5564  
  5565  func TestStructOfGC(t *testing.T) {
  5566  	type T *uintptr
  5567  	tt := TypeOf(T(nil))
  5568  	fields := []StructField{
  5569  		{Name: "X", Type: tt},
  5570  		{Name: "Y", Type: tt},
  5571  	}
  5572  	st := StructOf(fields)
  5573  
  5574  	const n = 10000
  5575  	var x []any
  5576  	for i := 0; i < n; i++ {
  5577  		v := New(st).Elem()
  5578  		for j := 0; j < v.NumField(); j++ {
  5579  			p := new(uintptr)
  5580  			*p = uintptr(i*n + j)
  5581  			v.Field(j).Set(ValueOf(p).Convert(tt))
  5582  		}
  5583  		x = append(x, v.Interface())
  5584  	}
  5585  	runtime.GC()
  5586  
  5587  	for i, xi := range x {
  5588  		v := ValueOf(xi)
  5589  		for j := 0; j < v.NumField(); j++ {
  5590  			k := v.Field(j).Elem().Interface()
  5591  			if k != uintptr(i*n+j) {
  5592  				t.Errorf("lost x[%d].%c = %d, want %d", i, "XY"[j], k, i*n+j)
  5593  			}
  5594  		}
  5595  	}
  5596  }
  5597  
  5598  func TestStructOfAlg(t *testing.T) {
  5599  	st := StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf(int(0))}})
  5600  	v1 := New(st).Elem()
  5601  	v2 := New(st).Elem()
  5602  	if !DeepEqual(v1.Interface(), v1.Interface()) {
  5603  		t.Errorf("constructed struct %v not equal to itself", v1.Interface())
  5604  	}
  5605  	v1.FieldByName("X").Set(ValueOf(int(1)))
  5606  	if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) {
  5607  		t.Errorf("constructed structs %v and %v should not be equal", i1, i2)
  5608  	}
  5609  
  5610  	st = StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf([]int(nil))}})
  5611  	v1 = New(st).Elem()
  5612  	shouldPanic("", func() { _ = v1.Interface() == v1.Interface() })
  5613  }
  5614  
  5615  func TestStructOfGenericAlg(t *testing.T) {
  5616  	st1 := StructOf([]StructField{
  5617  		{Name: "X", Tag: "x", Type: TypeOf(int64(0))},
  5618  		{Name: "Y", Type: TypeOf(string(""))},
  5619  	})
  5620  	st := StructOf([]StructField{
  5621  		{Name: "S0", Type: st1},
  5622  		{Name: "S1", Type: st1},
  5623  	})
  5624  
  5625  	tests := []struct {
  5626  		rt  Type
  5627  		idx []int
  5628  	}{
  5629  		{
  5630  			rt:  st,
  5631  			idx: []int{0, 1},
  5632  		},
  5633  		{
  5634  			rt:  st1,
  5635  			idx: []int{1},
  5636  		},
  5637  		{
  5638  			rt: StructOf(
  5639  				[]StructField{
  5640  					{Name: "XX", Type: TypeOf([0]int{})},
  5641  					{Name: "YY", Type: TypeOf("")},
  5642  				},
  5643  			),
  5644  			idx: []int{1},
  5645  		},
  5646  		{
  5647  			rt: StructOf(
  5648  				[]StructField{
  5649  					{Name: "XX", Type: TypeOf([0]int{})},
  5650  					{Name: "YY", Type: TypeOf("")},
  5651  					{Name: "ZZ", Type: TypeOf([2]int{})},
  5652  				},
  5653  			),
  5654  			idx: []int{1},
  5655  		},
  5656  		{
  5657  			rt: StructOf(
  5658  				[]StructField{
  5659  					{Name: "XX", Type: TypeOf([1]int{})},
  5660  					{Name: "YY", Type: TypeOf("")},
  5661  				},
  5662  			),
  5663  			idx: []int{1},
  5664  		},
  5665  		{
  5666  			rt: StructOf(
  5667  				[]StructField{
  5668  					{Name: "XX", Type: TypeOf([1]int{})},
  5669  					{Name: "YY", Type: TypeOf("")},
  5670  					{Name: "ZZ", Type: TypeOf([1]int{})},
  5671  				},
  5672  			),
  5673  			idx: []int{1},
  5674  		},
  5675  		{
  5676  			rt: StructOf(
  5677  				[]StructField{
  5678  					{Name: "XX", Type: TypeOf([2]int{})},
  5679  					{Name: "YY", Type: TypeOf("")},
  5680  					{Name: "ZZ", Type: TypeOf([2]int{})},
  5681  				},
  5682  			),
  5683  			idx: []int{1},
  5684  		},
  5685  		{
  5686  			rt: StructOf(
  5687  				[]StructField{
  5688  					{Name: "XX", Type: TypeOf(int64(0))},
  5689  					{Name: "YY", Type: TypeOf(byte(0))},
  5690  					{Name: "ZZ", Type: TypeOf("")},
  5691  				},
  5692  			),
  5693  			idx: []int{2},
  5694  		},
  5695  		{
  5696  			rt: StructOf(
  5697  				[]StructField{
  5698  					{Name: "XX", Type: TypeOf(int64(0))},
  5699  					{Name: "YY", Type: TypeOf(int64(0))},
  5700  					{Name: "ZZ", Type: TypeOf("")},
  5701  					{Name: "AA", Type: TypeOf([1]int64{})},
  5702  				},
  5703  			),
  5704  			idx: []int{2},
  5705  		},
  5706  	}
  5707  
  5708  	for _, table := range tests {
  5709  		v1 := New(table.rt).Elem()
  5710  		v2 := New(table.rt).Elem()
  5711  
  5712  		if !DeepEqual(v1.Interface(), v1.Interface()) {
  5713  			t.Errorf("constructed struct %v not equal to itself", v1.Interface())
  5714  		}
  5715  
  5716  		v1.FieldByIndex(table.idx).Set(ValueOf("abc"))
  5717  		v2.FieldByIndex(table.idx).Set(ValueOf("def"))
  5718  		if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) {
  5719  			t.Errorf("constructed structs %v and %v should not be equal", i1, i2)
  5720  		}
  5721  
  5722  		abc := "abc"
  5723  		v1.FieldByIndex(table.idx).Set(ValueOf(abc))
  5724  		val := "+" + abc + "-"
  5725  		v2.FieldByIndex(table.idx).Set(ValueOf(val[1:4]))
  5726  		if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) {
  5727  			t.Errorf("constructed structs %v and %v should be equal", i1, i2)
  5728  		}
  5729  
  5730  		// Test hash
  5731  		m := MakeMap(MapOf(table.rt, TypeOf(int(0))))
  5732  		m.SetMapIndex(v1, ValueOf(1))
  5733  		if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  5734  			t.Errorf("constructed structs %#v and %#v have different hashes", i1, i2)
  5735  		}
  5736  
  5737  		v2.FieldByIndex(table.idx).Set(ValueOf("abc"))
  5738  		if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) {
  5739  			t.Errorf("constructed structs %v and %v should be equal", i1, i2)
  5740  		}
  5741  
  5742  		if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  5743  			t.Errorf("constructed structs %v and %v have different hashes", i1, i2)
  5744  		}
  5745  	}
  5746  }
  5747  
  5748  func TestStructOfDirectIface(t *testing.T) {
  5749  	{
  5750  		type T struct{ X [1]*byte }
  5751  		i1 := Zero(TypeOf(T{})).Interface()
  5752  		v1 := ValueOf(&i1).Elem()
  5753  		p1 := v1.InterfaceData()[1]
  5754  
  5755  		i2 := Zero(StructOf([]StructField{
  5756  			{
  5757  				Name: "X",
  5758  				Type: ArrayOf(1, TypeOf((*int8)(nil))),
  5759  			},
  5760  		})).Interface()
  5761  		v2 := ValueOf(&i2).Elem()
  5762  		p2 := v2.InterfaceData()[1]
  5763  
  5764  		if p1 != 0 {
  5765  			t.Errorf("got p1=%v. want=%v", p1, nil)
  5766  		}
  5767  
  5768  		if p2 != 0 {
  5769  			t.Errorf("got p2=%v. want=%v", p2, nil)
  5770  		}
  5771  	}
  5772  	{
  5773  		type T struct{ X [0]*byte }
  5774  		i1 := Zero(TypeOf(T{})).Interface()
  5775  		v1 := ValueOf(&i1).Elem()
  5776  		p1 := v1.InterfaceData()[1]
  5777  
  5778  		i2 := Zero(StructOf([]StructField{
  5779  			{
  5780  				Name: "X",
  5781  				Type: ArrayOf(0, TypeOf((*int8)(nil))),
  5782  			},
  5783  		})).Interface()
  5784  		v2 := ValueOf(&i2).Elem()
  5785  		p2 := v2.InterfaceData()[1]
  5786  
  5787  		if p1 == 0 {
  5788  			t.Errorf("got p1=%v. want=not-%v", p1, nil)
  5789  		}
  5790  
  5791  		if p2 == 0 {
  5792  			t.Errorf("got p2=%v. want=not-%v", p2, nil)
  5793  		}
  5794  	}
  5795  }
  5796  
  5797  type StructI int
  5798  
  5799  func (i StructI) Get() int { return int(i) }
  5800  
  5801  type StructIPtr int
  5802  
  5803  func (i *StructIPtr) Get() int  { return int(*i) }
  5804  func (i *StructIPtr) Set(v int) { *(*int)(i) = v }
  5805  
  5806  type SettableStruct struct {
  5807  	SettableField int
  5808  }
  5809  
  5810  func (p *SettableStruct) Set(v int) { p.SettableField = v }
  5811  
  5812  type SettablePointer struct {
  5813  	SettableField *int
  5814  }
  5815  
  5816  func (p *SettablePointer) Set(v int) { *p.SettableField = v }
  5817  
  5818  func TestStructOfWithInterface(t *testing.T) {
  5819  	const want = 42
  5820  	type Iface interface {
  5821  		Get() int
  5822  	}
  5823  	type IfaceSet interface {
  5824  		Set(int)
  5825  	}
  5826  	tests := []struct {
  5827  		name string
  5828  		typ  Type
  5829  		val  Value
  5830  		impl bool
  5831  	}{
  5832  		{
  5833  			name: "StructI",
  5834  			typ:  TypeOf(StructI(want)),
  5835  			val:  ValueOf(StructI(want)),
  5836  			impl: true,
  5837  		},
  5838  		{
  5839  			name: "StructI",
  5840  			typ:  PointerTo(TypeOf(StructI(want))),
  5841  			val: ValueOf(func() any {
  5842  				v := StructI(want)
  5843  				return &v
  5844  			}()),
  5845  			impl: true,
  5846  		},
  5847  		{
  5848  			name: "StructIPtr",
  5849  			typ:  PointerTo(TypeOf(StructIPtr(want))),
  5850  			val: ValueOf(func() any {
  5851  				v := StructIPtr(want)
  5852  				return &v
  5853  			}()),
  5854  			impl: true,
  5855  		},
  5856  		{
  5857  			name: "StructIPtr",
  5858  			typ:  TypeOf(StructIPtr(want)),
  5859  			val:  ValueOf(StructIPtr(want)),
  5860  			impl: false,
  5861  		},
  5862  		// {
  5863  		//	typ:  TypeOf((*Iface)(nil)).Elem(), // FIXME(sbinet): fix method.ifn/tfn
  5864  		//	val:  ValueOf(StructI(want)),
  5865  		//	impl: true,
  5866  		// },
  5867  	}
  5868  
  5869  	for i, table := range tests {
  5870  		for j := 0; j < 2; j++ {
  5871  			var fields []StructField
  5872  			if j == 1 {
  5873  				fields = append(fields, StructField{
  5874  					Name:    "Dummy",
  5875  					PkgPath: "",
  5876  					Type:    TypeOf(int(0)),
  5877  				})
  5878  			}
  5879  			fields = append(fields, StructField{
  5880  				Name:      table.name,
  5881  				Anonymous: true,
  5882  				PkgPath:   "",
  5883  				Type:      table.typ,
  5884  			})
  5885  
  5886  			// We currently do not correctly implement methods
  5887  			// for embedded fields other than the first.
  5888  			// Therefore, for now, we expect those methods
  5889  			// to not exist.  See issues 15924 and 20824.
  5890  			// When those issues are fixed, this test of panic
  5891  			// should be removed.
  5892  			if j == 1 && table.impl {
  5893  				func() {
  5894  					defer func() {
  5895  						if err := recover(); err == nil {
  5896  							t.Errorf("test-%d-%d did not panic", i, j)
  5897  						}
  5898  					}()
  5899  					_ = StructOf(fields)
  5900  				}()
  5901  				continue
  5902  			}
  5903  
  5904  			rt := StructOf(fields)
  5905  			rv := New(rt).Elem()
  5906  			rv.Field(j).Set(table.val)
  5907  
  5908  			if _, ok := rv.Interface().(Iface); ok != table.impl {
  5909  				if table.impl {
  5910  					t.Errorf("test-%d-%d: type=%v fails to implement Iface.\n", i, j, table.typ)
  5911  				} else {
  5912  					t.Errorf("test-%d-%d: type=%v should NOT implement Iface\n", i, j, table.typ)
  5913  				}
  5914  				continue
  5915  			}
  5916  
  5917  			if !table.impl {
  5918  				continue
  5919  			}
  5920  
  5921  			v := rv.Interface().(Iface).Get()
  5922  			if v != want {
  5923  				t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, v, want)
  5924  			}
  5925  
  5926  			fct := rv.MethodByName("Get")
  5927  			out := fct.Call(nil)
  5928  			if !DeepEqual(out[0].Interface(), want) {
  5929  				t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, out[0].Interface(), want)
  5930  			}
  5931  		}
  5932  	}
  5933  
  5934  	// Test an embedded nil pointer with pointer methods.
  5935  	fields := []StructField{{
  5936  		Name:      "StructIPtr",
  5937  		Anonymous: true,
  5938  		Type:      PointerTo(TypeOf(StructIPtr(want))),
  5939  	}}
  5940  	rt := StructOf(fields)
  5941  	rv := New(rt).Elem()
  5942  	// This should panic since the pointer is nil.
  5943  	shouldPanic("", func() {
  5944  		rv.Interface().(IfaceSet).Set(want)
  5945  	})
  5946  
  5947  	// Test an embedded nil pointer to a struct with pointer methods.
  5948  
  5949  	fields = []StructField{{
  5950  		Name:      "SettableStruct",
  5951  		Anonymous: true,
  5952  		Type:      PointerTo(TypeOf(SettableStruct{})),
  5953  	}}
  5954  	rt = StructOf(fields)
  5955  	rv = New(rt).Elem()
  5956  	// This should panic since the pointer is nil.
  5957  	shouldPanic("", func() {
  5958  		rv.Interface().(IfaceSet).Set(want)
  5959  	})
  5960  
  5961  	// The behavior is different if there is a second field,
  5962  	// since now an interface value holds a pointer to the struct
  5963  	// rather than just holding a copy of the struct.
  5964  	fields = []StructField{
  5965  		{
  5966  			Name:      "SettableStruct",
  5967  			Anonymous: true,
  5968  			Type:      PointerTo(TypeOf(SettableStruct{})),
  5969  		},
  5970  		{
  5971  			Name:      "EmptyStruct",
  5972  			Anonymous: true,
  5973  			Type:      StructOf(nil),
  5974  		},
  5975  	}
  5976  	// With the current implementation this is expected to panic.
  5977  	// Ideally it should work and we should be able to see a panic
  5978  	// if we call the Set method.
  5979  	shouldPanic("", func() {
  5980  		StructOf(fields)
  5981  	})
  5982  
  5983  	// Embed a field that can be stored directly in an interface,
  5984  	// with a second field.
  5985  	fields = []StructField{
  5986  		{
  5987  			Name:      "SettablePointer",
  5988  			Anonymous: true,
  5989  			Type:      TypeOf(SettablePointer{}),
  5990  		},
  5991  		{
  5992  			Name:      "EmptyStruct",
  5993  			Anonymous: true,
  5994  			Type:      StructOf(nil),
  5995  		},
  5996  	}
  5997  	// With the current implementation this is expected to panic.
  5998  	// Ideally it should work and we should be able to call the
  5999  	// Set and Get methods.
  6000  	shouldPanic("", func() {
  6001  		StructOf(fields)
  6002  	})
  6003  }
  6004  
  6005  func TestStructOfTooManyFields(t *testing.T) {
  6006  	// Bug Fix: #25402 - this should not panic
  6007  	tt := StructOf([]StructField{
  6008  		{Name: "Time", Type: TypeOf(time.Time{}), Anonymous: true},
  6009  	})
  6010  
  6011  	if _, present := tt.MethodByName("After"); !present {
  6012  		t.Errorf("Expected method `After` to be found")
  6013  	}
  6014  }
  6015  
  6016  func TestStructOfDifferentPkgPath(t *testing.T) {
  6017  	fields := []StructField{
  6018  		{
  6019  			Name:    "f1",
  6020  			PkgPath: "p1",
  6021  			Type:    TypeOf(int(0)),
  6022  		},
  6023  		{
  6024  			Name:    "f2",
  6025  			PkgPath: "p2",
  6026  			Type:    TypeOf(int(0)),
  6027  		},
  6028  	}
  6029  	shouldPanic("different PkgPath", func() {
  6030  		StructOf(fields)
  6031  	})
  6032  }
  6033  
  6034  func TestStructOfTooLarge(t *testing.T) {
  6035  	t1 := TypeOf(byte(0))
  6036  	t2 := TypeOf(int16(0))
  6037  	t4 := TypeOf(int32(0))
  6038  	t0 := ArrayOf(0, t1)
  6039  
  6040  	// 2^64-3 sized type (or 2^32-3 on 32-bit archs)
  6041  	bigType := StructOf([]StructField{
  6042  		{Name: "F1", Type: ArrayOf(int(^uintptr(0)>>1), t1)},
  6043  		{Name: "F2", Type: ArrayOf(int(^uintptr(0)>>1-1), t1)},
  6044  	})
  6045  
  6046  	type test struct {
  6047  		shouldPanic bool
  6048  		fields      []StructField
  6049  	}
  6050  
  6051  	tests := [...]test{
  6052  		{
  6053  			shouldPanic: false, // 2^64-1, ok
  6054  			fields: []StructField{
  6055  				{Name: "F1", Type: bigType},
  6056  				{Name: "F2", Type: ArrayOf(2, t1)},
  6057  			},
  6058  		},
  6059  		{
  6060  			shouldPanic: true, // overflow in total size
  6061  			fields: []StructField{
  6062  				{Name: "F1", Type: bigType},
  6063  				{Name: "F2", Type: ArrayOf(3, t1)},
  6064  			},
  6065  		},
  6066  		{
  6067  			shouldPanic: true, // overflow while aligning F2
  6068  			fields: []StructField{
  6069  				{Name: "F1", Type: bigType},
  6070  				{Name: "F2", Type: t4},
  6071  			},
  6072  		},
  6073  		{
  6074  			shouldPanic: true, // overflow while adding trailing byte for zero-sized fields
  6075  			fields: []StructField{
  6076  				{Name: "F1", Type: bigType},
  6077  				{Name: "F2", Type: ArrayOf(2, t1)},
  6078  				{Name: "F3", Type: t0},
  6079  			},
  6080  		},
  6081  		{
  6082  			shouldPanic: true, // overflow while aligning total size
  6083  			fields: []StructField{
  6084  				{Name: "F1", Type: t2},
  6085  				{Name: "F2", Type: bigType},
  6086  			},
  6087  		},
  6088  	}
  6089  
  6090  	for i, tt := range tests {
  6091  		func() {
  6092  			defer func() {
  6093  				err := recover()
  6094  				if !tt.shouldPanic {
  6095  					if err != nil {
  6096  						t.Errorf("test %d should not panic, got %s", i, err)
  6097  					}
  6098  					return
  6099  				}
  6100  				if err == nil {
  6101  					t.Errorf("test %d expected to panic", i)
  6102  					return
  6103  				}
  6104  				s := fmt.Sprintf("%s", err)
  6105  				if s != "reflect.StructOf: struct size would exceed virtual address space" {
  6106  					t.Errorf("test %d wrong panic message: %s", i, s)
  6107  					return
  6108  				}
  6109  			}()
  6110  			_ = StructOf(tt.fields)
  6111  		}()
  6112  	}
  6113  }
  6114  
  6115  func TestStructOfAnonymous(t *testing.T) {
  6116  	var s any = struct{ D1 }{}
  6117  	f := TypeOf(s).Field(0)
  6118  	ds := StructOf([]StructField{f})
  6119  	st := TypeOf(s)
  6120  	dt := New(ds).Elem()
  6121  	if st != dt.Type() {
  6122  		t.Errorf("StructOf returned %s, want %s", dt.Type(), st)
  6123  	}
  6124  
  6125  	// This should not panic.
  6126  	_ = dt.Interface().(struct{ D1 })
  6127  }
  6128  
  6129  func TestChanOf(t *testing.T) {
  6130  	// check construction and use of type not in binary
  6131  	type T string
  6132  	ct := ChanOf(BothDir, TypeOf(T("")))
  6133  	v := MakeChan(ct, 2)
  6134  	runtime.GC()
  6135  	v.Send(ValueOf(T("hello")))
  6136  	runtime.GC()
  6137  	v.Send(ValueOf(T("world")))
  6138  	runtime.GC()
  6139  
  6140  	sv1, _ := v.Recv()
  6141  	sv2, _ := v.Recv()
  6142  	s1 := sv1.String()
  6143  	s2 := sv2.String()
  6144  	if s1 != "hello" || s2 != "world" {
  6145  		t.Errorf("constructed chan: have %q, %q, want %q, %q", s1, s2, "hello", "world")
  6146  	}
  6147  
  6148  	// check that type already in binary is found
  6149  	type T1 int
  6150  	checkSameType(t, ChanOf(BothDir, TypeOf(T1(1))), (chan T1)(nil))
  6151  
  6152  	// Check arrow token association in undefined chan types.
  6153  	var left chan<- chan T
  6154  	var right chan (<-chan T)
  6155  	tLeft := ChanOf(SendDir, ChanOf(BothDir, TypeOf(T(""))))
  6156  	tRight := ChanOf(BothDir, ChanOf(RecvDir, TypeOf(T(""))))
  6157  	if tLeft != TypeOf(left) {
  6158  		t.Errorf("chan<-chan: have %s, want %T", tLeft, left)
  6159  	}
  6160  	if tRight != TypeOf(right) {
  6161  		t.Errorf("chan<-chan: have %s, want %T", tRight, right)
  6162  	}
  6163  }
  6164  
  6165  func TestChanOfDir(t *testing.T) {
  6166  	// check construction and use of type not in binary
  6167  	type T string
  6168  	crt := ChanOf(RecvDir, TypeOf(T("")))
  6169  	cst := ChanOf(SendDir, TypeOf(T("")))
  6170  
  6171  	// check that type already in binary is found
  6172  	type T1 int
  6173  	checkSameType(t, ChanOf(RecvDir, TypeOf(T1(1))), (<-chan T1)(nil))
  6174  	checkSameType(t, ChanOf(SendDir, TypeOf(T1(1))), (chan<- T1)(nil))
  6175  
  6176  	// check String form of ChanDir
  6177  	if crt.ChanDir().String() != "<-chan" {
  6178  		t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan")
  6179  	}
  6180  	if cst.ChanDir().String() != "chan<-" {
  6181  		t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-")
  6182  	}
  6183  }
  6184  
  6185  func TestChanOfGC(t *testing.T) {
  6186  	done := make(chan bool, 1)
  6187  	go func() {
  6188  		select {
  6189  		case <-done:
  6190  		case <-time.After(5 * time.Second):
  6191  			panic("deadlock in TestChanOfGC")
  6192  		}
  6193  	}()
  6194  
  6195  	defer func() {
  6196  		done <- true
  6197  	}()
  6198  
  6199  	type T *uintptr
  6200  	tt := TypeOf(T(nil))
  6201  	ct := ChanOf(BothDir, tt)
  6202  
  6203  	// NOTE: The garbage collector handles allocated channels specially,
  6204  	// so we have to save pointers to channels in x; the pointer code will
  6205  	// use the gc info in the newly constructed chan type.
  6206  	const n = 100
  6207  	var x []any
  6208  	for i := 0; i < n; i++ {
  6209  		v := MakeChan(ct, n)
  6210  		for j := 0; j < n; j++ {
  6211  			p := new(uintptr)
  6212  			*p = uintptr(i*n + j)
  6213  			v.Send(ValueOf(p).Convert(tt))
  6214  		}
  6215  		pv := New(ct)
  6216  		pv.Elem().Set(v)
  6217  		x = append(x, pv.Interface())
  6218  	}
  6219  	runtime.GC()
  6220  
  6221  	for i, xi := range x {
  6222  		v := ValueOf(xi).Elem()
  6223  		for j := 0; j < n; j++ {
  6224  			pv, _ := v.Recv()
  6225  			k := pv.Elem().Interface()
  6226  			if k != uintptr(i*n+j) {
  6227  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  6228  			}
  6229  		}
  6230  	}
  6231  }
  6232  
  6233  func TestMapOf(t *testing.T) {
  6234  	// check construction and use of type not in binary
  6235  	type K string
  6236  	type V float64
  6237  
  6238  	v := MakeMap(MapOf(TypeOf(K("")), TypeOf(V(0))))
  6239  	runtime.GC()
  6240  	v.SetMapIndex(ValueOf(K("a")), ValueOf(V(1)))
  6241  	runtime.GC()
  6242  
  6243  	s := fmt.Sprint(v.Interface())
  6244  	want := "map[a:1]"
  6245  	if s != want {
  6246  		t.Errorf("constructed map = %s, want %s", s, want)
  6247  	}
  6248  
  6249  	// check that type already in binary is found
  6250  	checkSameType(t, MapOf(TypeOf(V(0)), TypeOf(K(""))), map[V]K(nil))
  6251  
  6252  	// check that invalid key type panics
  6253  	shouldPanic("invalid key type", func() { MapOf(TypeOf((func())(nil)), TypeOf(false)) })
  6254  }
  6255  
  6256  func TestMapOfGCKeys(t *testing.T) {
  6257  	type T *uintptr
  6258  	tt := TypeOf(T(nil))
  6259  	mt := MapOf(tt, TypeOf(false))
  6260  
  6261  	// NOTE: The garbage collector handles allocated maps specially,
  6262  	// so we have to save pointers to maps in x; the pointer code will
  6263  	// use the gc info in the newly constructed map type.
  6264  	const n = 100
  6265  	var x []any
  6266  	for i := 0; i < n; i++ {
  6267  		v := MakeMap(mt)
  6268  		for j := 0; j < n; j++ {
  6269  			p := new(uintptr)
  6270  			*p = uintptr(i*n + j)
  6271  			v.SetMapIndex(ValueOf(p).Convert(tt), ValueOf(true))
  6272  		}
  6273  		pv := New(mt)
  6274  		pv.Elem().Set(v)
  6275  		x = append(x, pv.Interface())
  6276  	}
  6277  	runtime.GC()
  6278  
  6279  	for i, xi := range x {
  6280  		v := ValueOf(xi).Elem()
  6281  		var out []int
  6282  		for _, kv := range v.MapKeys() {
  6283  			out = append(out, int(kv.Elem().Interface().(uintptr)))
  6284  		}
  6285  		slices.Sort(out)
  6286  		for j, k := range out {
  6287  			if k != i*n+j {
  6288  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  6289  			}
  6290  		}
  6291  	}
  6292  }
  6293  
  6294  func TestMapOfGCValues(t *testing.T) {
  6295  	type T *uintptr
  6296  	tt := TypeOf(T(nil))
  6297  	mt := MapOf(TypeOf(1), tt)
  6298  
  6299  	// NOTE: The garbage collector handles allocated maps specially,
  6300  	// so we have to save pointers to maps in x; the pointer code will
  6301  	// use the gc info in the newly constructed map type.
  6302  	const n = 100
  6303  	var x []any
  6304  	for i := 0; i < n; i++ {
  6305  		v := MakeMap(mt)
  6306  		for j := 0; j < n; j++ {
  6307  			p := new(uintptr)
  6308  			*p = uintptr(i*n + j)
  6309  			v.SetMapIndex(ValueOf(j), ValueOf(p).Convert(tt))
  6310  		}
  6311  		pv := New(mt)
  6312  		pv.Elem().Set(v)
  6313  		x = append(x, pv.Interface())
  6314  	}
  6315  	runtime.GC()
  6316  
  6317  	for i, xi := range x {
  6318  		v := ValueOf(xi).Elem()
  6319  		for j := 0; j < n; j++ {
  6320  			k := v.MapIndex(ValueOf(j)).Elem().Interface().(uintptr)
  6321  			if k != uintptr(i*n+j) {
  6322  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  6323  			}
  6324  		}
  6325  	}
  6326  }
  6327  
  6328  func TestTypelinksSorted(t *testing.T) {
  6329  	var last string
  6330  	for i, n := range TypeLinks() {
  6331  		if n < last {
  6332  			t.Errorf("typelinks not sorted: %q [%d] > %q [%d]", last, i-1, n, i)
  6333  		}
  6334  		last = n
  6335  	}
  6336  }
  6337  
  6338  func TestFuncOf(t *testing.T) {
  6339  	// check construction and use of type not in binary
  6340  	type K string
  6341  	type V float64
  6342  
  6343  	fn := func(args []Value) []Value {
  6344  		if len(args) != 1 {
  6345  			t.Errorf("args == %v, want exactly one arg", args)
  6346  		} else if args[0].Type() != TypeOf(K("")) {
  6347  			t.Errorf("args[0] is type %v, want %v", args[0].Type(), TypeOf(K("")))
  6348  		} else if args[0].String() != "gopher" {
  6349  			t.Errorf("args[0] = %q, want %q", args[0].String(), "gopher")
  6350  		}
  6351  		return []Value{ValueOf(V(3.14))}
  6352  	}
  6353  	v := MakeFunc(FuncOf([]Type{TypeOf(K(""))}, []Type{TypeOf(V(0))}, false), fn)
  6354  
  6355  	outs := v.Call([]Value{ValueOf(K("gopher"))})
  6356  	if len(outs) != 1 {
  6357  		t.Fatalf("v.Call returned %v, want exactly one result", outs)
  6358  	} else if outs[0].Type() != TypeOf(V(0)) {
  6359  		t.Fatalf("c.Call[0] is type %v, want %v", outs[0].Type(), TypeOf(V(0)))
  6360  	}
  6361  	f := outs[0].Float()
  6362  	if f != 3.14 {
  6363  		t.Errorf("constructed func returned %f, want %f", f, 3.14)
  6364  	}
  6365  
  6366  	// check that types already in binary are found
  6367  	type T1 int
  6368  	testCases := []struct {
  6369  		in, out  []Type
  6370  		variadic bool
  6371  		want     any
  6372  	}{
  6373  		{in: []Type{TypeOf(T1(0))}, want: (func(T1))(nil)},
  6374  		{in: []Type{TypeOf(int(0))}, want: (func(int))(nil)},
  6375  		{in: []Type{SliceOf(TypeOf(int(0)))}, variadic: true, want: (func(...int))(nil)},
  6376  		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false)}, want: (func(int) bool)(nil)},
  6377  		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false), TypeOf("")}, want: (func(int) (bool, string))(nil)},
  6378  	}
  6379  	for _, tt := range testCases {
  6380  		checkSameType(t, FuncOf(tt.in, tt.out, tt.variadic), tt.want)
  6381  	}
  6382  
  6383  	// check that variadic requires last element be a slice.
  6384  	FuncOf([]Type{TypeOf(1), TypeOf(""), SliceOf(TypeOf(false))}, nil, true)
  6385  	shouldPanic("must be slice", func() { FuncOf([]Type{TypeOf(0), TypeOf(""), TypeOf(false)}, nil, true) })
  6386  	shouldPanic("must be slice", func() { FuncOf(nil, nil, true) })
  6387  
  6388  	//testcase for  #54669
  6389  	var in []Type
  6390  	for i := 0; i < 51; i++ {
  6391  		in = append(in, TypeOf(1))
  6392  	}
  6393  	FuncOf(in, nil, false)
  6394  }
  6395  
  6396  type R0 struct {
  6397  	*R1
  6398  	*R2
  6399  	*R3
  6400  	*R4
  6401  }
  6402  
  6403  type R1 struct {
  6404  	*R5
  6405  	*R6
  6406  	*R7
  6407  	*R8
  6408  }
  6409  
  6410  type R2 R1
  6411  type R3 R1
  6412  type R4 R1
  6413  
  6414  type R5 struct {
  6415  	*R9
  6416  	*R10
  6417  	*R11
  6418  	*R12
  6419  }
  6420  
  6421  type R6 R5
  6422  type R7 R5
  6423  type R8 R5
  6424  
  6425  type R9 struct {
  6426  	*R13
  6427  	*R14
  6428  	*R15
  6429  	*R16
  6430  }
  6431  
  6432  type R10 R9
  6433  type R11 R9
  6434  type R12 R9
  6435  
  6436  type R13 struct {
  6437  	*R17
  6438  	*R18
  6439  	*R19
  6440  	*R20
  6441  }
  6442  
  6443  type R14 R13
  6444  type R15 R13
  6445  type R16 R13
  6446  
  6447  type R17 struct {
  6448  	*R21
  6449  	*R22
  6450  	*R23
  6451  	*R24
  6452  }
  6453  
  6454  type R18 R17
  6455  type R19 R17
  6456  type R20 R17
  6457  
  6458  type R21 struct {
  6459  	X int
  6460  }
  6461  
  6462  type R22 R21
  6463  type R23 R21
  6464  type R24 R21
  6465  
  6466  func TestEmbed(t *testing.T) {
  6467  	typ := TypeOf(R0{})
  6468  	f, ok := typ.FieldByName("X")
  6469  	if ok {
  6470  		t.Fatalf(`FieldByName("X") should fail, returned %v`, f.Index)
  6471  	}
  6472  }
  6473  
  6474  func TestAllocsInterfaceBig(t *testing.T) {
  6475  	if testing.Short() {
  6476  		t.Skip("skipping malloc count in short mode")
  6477  	}
  6478  	v := ValueOf(S{})
  6479  	if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
  6480  		t.Error("allocs:", allocs)
  6481  	}
  6482  }
  6483  
  6484  func TestAllocsInterfaceSmall(t *testing.T) {
  6485  	if testing.Short() {
  6486  		t.Skip("skipping malloc count in short mode")
  6487  	}
  6488  	v := ValueOf(int64(0))
  6489  	if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
  6490  		t.Error("allocs:", allocs)
  6491  	}
  6492  }
  6493  
  6494  // An exhaustive is a mechanism for writing exhaustive or stochastic tests.
  6495  // The basic usage is:
  6496  //
  6497  //	for x.Next() {
  6498  //		... code using x.Maybe() or x.Choice(n) to create test cases ...
  6499  //	}
  6500  //
  6501  // Each iteration of the loop returns a different set of results, until all
  6502  // possible result sets have been explored. It is okay for different code paths
  6503  // to make different method call sequences on x, but there must be no
  6504  // other source of non-determinism in the call sequences.
  6505  //
  6506  // When faced with a new decision, x chooses randomly. Future explorations
  6507  // of that path will choose successive values for the result. Thus, stopping
  6508  // the loop after a fixed number of iterations gives somewhat stochastic
  6509  // testing.
  6510  //
  6511  // Example:
  6512  //
  6513  //	for x.Next() {
  6514  //		v := make([]bool, x.Choose(4))
  6515  //		for i := range v {
  6516  //			v[i] = x.Maybe()
  6517  //		}
  6518  //		fmt.Println(v)
  6519  //	}
  6520  //
  6521  // prints (in some order):
  6522  //
  6523  //	[]
  6524  //	[false]
  6525  //	[true]
  6526  //	[false false]
  6527  //	[false true]
  6528  //	...
  6529  //	[true true]
  6530  //	[false false false]
  6531  //	...
  6532  //	[true true true]
  6533  //	[false false false false]
  6534  //	...
  6535  //	[true true true true]
  6536  type exhaustive struct {
  6537  	r    *rand.Rand
  6538  	pos  int
  6539  	last []choice
  6540  }
  6541  
  6542  type choice struct {
  6543  	off int
  6544  	n   int
  6545  	max int
  6546  }
  6547  
  6548  func (x *exhaustive) Next() bool {
  6549  	if x.r == nil {
  6550  		x.r = rand.New(rand.NewSource(time.Now().UnixNano()))
  6551  	}
  6552  	x.pos = 0
  6553  	if x.last == nil {
  6554  		x.last = []choice{}
  6555  		return true
  6556  	}
  6557  	for i := len(x.last) - 1; i >= 0; i-- {
  6558  		c := &x.last[i]
  6559  		if c.n+1 < c.max {
  6560  			c.n++
  6561  			x.last = x.last[:i+1]
  6562  			return true
  6563  		}
  6564  	}
  6565  	return false
  6566  }
  6567  
  6568  func (x *exhaustive) Choose(max int) int {
  6569  	if x.pos >= len(x.last) {
  6570  		x.last = append(x.last, choice{x.r.Intn(max), 0, max})
  6571  	}
  6572  	c := &x.last[x.pos]
  6573  	x.pos++
  6574  	if c.max != max {
  6575  		panic("inconsistent use of exhaustive tester")
  6576  	}
  6577  	return (c.n + c.off) % max
  6578  }
  6579  
  6580  func (x *exhaustive) Maybe() bool {
  6581  	return x.Choose(2) == 1
  6582  }
  6583  
  6584  func GCFunc(args []Value) []Value {
  6585  	runtime.GC()
  6586  	return []Value{}
  6587  }
  6588  
  6589  func TestReflectFuncTraceback(t *testing.T) {
  6590  	f := MakeFunc(TypeOf(func() {}), GCFunc)
  6591  	f.Call([]Value{})
  6592  }
  6593  
  6594  func TestReflectMethodTraceback(t *testing.T) {
  6595  	p := Point{3, 4}
  6596  	m := ValueOf(p).MethodByName("GCMethod")
  6597  	i := ValueOf(m.Interface()).Call([]Value{ValueOf(5)})[0].Int()
  6598  	if i != 8 {
  6599  		t.Errorf("Call returned %d; want 8", i)
  6600  	}
  6601  }
  6602  
  6603  func TestSmallZero(t *testing.T) {
  6604  	type T [10]byte
  6605  	typ := TypeOf(T{})
  6606  	if allocs := testing.AllocsPerRun(100, func() { Zero(typ) }); allocs > 0 {
  6607  		t.Errorf("Creating small zero values caused %f allocs, want 0", allocs)
  6608  	}
  6609  }
  6610  
  6611  func TestBigZero(t *testing.T) {
  6612  	const size = 1 << 10
  6613  	var v [size]byte
  6614  	z := Zero(ValueOf(v).Type()).Interface().([size]byte)
  6615  	for i := 0; i < size; i++ {
  6616  		if z[i] != 0 {
  6617  			t.Fatalf("Zero object not all zero, index %d", i)
  6618  		}
  6619  	}
  6620  }
  6621  
  6622  func TestZeroSet(t *testing.T) {
  6623  	type T [16]byte
  6624  	type S struct {
  6625  		a uint64
  6626  		T T
  6627  		b uint64
  6628  	}
  6629  	v := S{
  6630  		a: 0xaaaaaaaaaaaaaaaa,
  6631  		T: T{9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9},
  6632  		b: 0xbbbbbbbbbbbbbbbb,
  6633  	}
  6634  	ValueOf(&v).Elem().Field(1).Set(Zero(TypeOf(T{})))
  6635  	if v != (S{
  6636  		a: 0xaaaaaaaaaaaaaaaa,
  6637  		b: 0xbbbbbbbbbbbbbbbb,
  6638  	}) {
  6639  		t.Fatalf("Setting a field to a Zero value didn't work")
  6640  	}
  6641  }
  6642  
  6643  func TestFieldByIndexNil(t *testing.T) {
  6644  	type P struct {
  6645  		F int
  6646  	}
  6647  	type T struct {
  6648  		*P
  6649  	}
  6650  	v := ValueOf(T{})
  6651  
  6652  	v.FieldByName("P") // should be fine
  6653  
  6654  	defer func() {
  6655  		if err := recover(); err == nil {
  6656  			t.Fatalf("no error")
  6657  		} else if !strings.Contains(fmt.Sprint(err), "nil pointer to embedded struct") {
  6658  			t.Fatalf(`err=%q, wanted error containing "nil pointer to embedded struct"`, err)
  6659  		}
  6660  	}()
  6661  	v.FieldByName("F") // should panic
  6662  
  6663  	t.Fatalf("did not panic")
  6664  }
  6665  
  6666  // Given
  6667  //	type Outer struct {
  6668  //		*Inner
  6669  //		...
  6670  //	}
  6671  // the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner.
  6672  // The implementation is logically:
  6673  //	func (p *Outer) M() {
  6674  //		(p.Inner).M()
  6675  //	}
  6676  // but since the only change here is the replacement of one pointer receiver with another,
  6677  // the actual generated code overwrites the original receiver with the p.Inner pointer and
  6678  // then jumps to the M method expecting the *Inner receiver.
  6679  //
  6680  // During reflect.Value.Call, we create an argument frame and the associated data structures
  6681  // to describe it to the garbage collector, populate the frame, call reflect.call to
  6682  // run a function call using that frame, and then copy the results back out of the frame.
  6683  // The reflect.call function does a memmove of the frame structure onto the
  6684  // stack (to set up the inputs), runs the call, and the memmoves the stack back to
  6685  // the frame structure (to preserve the outputs).
  6686  //
  6687  // Originally reflect.call did not distinguish inputs from outputs: both memmoves
  6688  // were for the full stack frame. However, in the case where the called function was
  6689  // one of these wrappers, the rewritten receiver is almost certainly a different type
  6690  // than the original receiver. This is not a problem on the stack, where we use the
  6691  // program counter to determine the type information and understand that
  6692  // during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same
  6693  // memory word is now an *Inner. But in the statically typed argument frame created
  6694  // by reflect, the receiver is always an *Outer. Copying the modified receiver pointer
  6695  // off the stack into the frame will store an *Inner there, and then if a garbage collection
  6696  // happens to scan that argument frame before it is discarded, it will scan the *Inner
  6697  // memory as if it were an *Outer. If the two have different memory layouts, the
  6698  // collection will interpret the memory incorrectly.
  6699  //
  6700  // One such possible incorrect interpretation is to treat two arbitrary memory words
  6701  // (Inner.P1 and Inner.P2 below) as an interface (Outer.R below). Because interpreting
  6702  // an interface requires dereferencing the itab word, the misinterpretation will try to
  6703  // deference Inner.P1, causing a crash during garbage collection.
  6704  //
  6705  // This came up in a real program in issue 7725.
  6706  
  6707  type Outer struct {
  6708  	*Inner
  6709  	R io.Reader
  6710  }
  6711  
  6712  type Inner struct {
  6713  	X  *Outer
  6714  	P1 uintptr
  6715  	P2 uintptr
  6716  }
  6717  
  6718  func (pi *Inner) M() {
  6719  	// Clear references to pi so that the only way the
  6720  	// garbage collection will find the pointer is in the
  6721  	// argument frame, typed as a *Outer.
  6722  	pi.X.Inner = nil
  6723  
  6724  	// Set up an interface value that will cause a crash.
  6725  	// P1 = 1 is a non-zero, so the interface looks non-nil.
  6726  	// P2 = pi ensures that the data word points into the
  6727  	// allocated heap; if not the collection skips the interface
  6728  	// value as irrelevant, without dereferencing P1.
  6729  	pi.P1 = 1
  6730  	pi.P2 = uintptr(unsafe.Pointer(pi))
  6731  }
  6732  
  6733  func TestCallMethodJump(t *testing.T) {
  6734  	// In reflect.Value.Call, trigger a garbage collection after reflect.call
  6735  	// returns but before the args frame has been discarded.
  6736  	// This is a little clumsy but makes the failure repeatable.
  6737  	*CallGC = true
  6738  
  6739  	p := &Outer{Inner: new(Inner)}
  6740  	p.Inner.X = p
  6741  	ValueOf(p).Method(0).Call(nil)
  6742  
  6743  	// Stop garbage collecting during reflect.call.
  6744  	*CallGC = false
  6745  }
  6746  
  6747  func TestCallArgLive(t *testing.T) {
  6748  	type T struct{ X, Y *string } // pointerful aggregate
  6749  
  6750  	F := func(t T) { *t.X = "ok" }
  6751  
  6752  	// In reflect.Value.Call, trigger a garbage collection in reflect.call
  6753  	// between marshaling argument and the actual call.
  6754  	*CallGC = true
  6755  
  6756  	x := new(string)
  6757  	runtime.SetFinalizer(x, func(p *string) {
  6758  		if *p != "ok" {
  6759  			t.Errorf("x dead prematurely")
  6760  		}
  6761  	})
  6762  	v := T{x, nil}
  6763  
  6764  	ValueOf(F).Call([]Value{ValueOf(v)})
  6765  
  6766  	// Stop garbage collecting during reflect.call.
  6767  	*CallGC = false
  6768  }
  6769  
  6770  func TestMakeFuncStackCopy(t *testing.T) {
  6771  	target := func(in []Value) []Value {
  6772  		runtime.GC()
  6773  		useStack(16)
  6774  		return []Value{ValueOf(9)}
  6775  	}
  6776  
  6777  	var concrete func(*int, int) int
  6778  	fn := MakeFunc(ValueOf(concrete).Type(), target)
  6779  	ValueOf(&concrete).Elem().Set(fn)
  6780  	x := concrete(nil, 7)
  6781  	if x != 9 {
  6782  		t.Errorf("have %#q want 9", x)
  6783  	}
  6784  }
  6785  
  6786  // use about n KB of stack
  6787  func useStack(n int) {
  6788  	if n == 0 {
  6789  		return
  6790  	}
  6791  	var b [1024]byte // makes frame about 1KB
  6792  	useStack(n - 1 + int(b[99]))
  6793  }
  6794  
  6795  type Impl struct{}
  6796  
  6797  func (Impl) F() {}
  6798  
  6799  func TestValueString(t *testing.T) {
  6800  	rv := ValueOf(Impl{})
  6801  	if rv.String() != "<reflect_test.Impl Value>" {
  6802  		t.Errorf("ValueOf(Impl{}).String() = %q, want %q", rv.String(), "<reflect_test.Impl Value>")
  6803  	}
  6804  
  6805  	method := rv.Method(0)
  6806  	if method.String() != "<func() Value>" {
  6807  		t.Errorf("ValueOf(Impl{}).Method(0).String() = %q, want %q", method.String(), "<func() Value>")
  6808  	}
  6809  }
  6810  
  6811  func TestInvalid(t *testing.T) {
  6812  	// Used to have inconsistency between IsValid() and Kind() != Invalid.
  6813  	type T struct{ v any }
  6814  
  6815  	v := ValueOf(T{}).Field(0)
  6816  	if v.IsValid() != true || v.Kind() != Interface {
  6817  		t.Errorf("field: IsValid=%v, Kind=%v, want true, Interface", v.IsValid(), v.Kind())
  6818  	}
  6819  	v = v.Elem()
  6820  	if v.IsValid() != false || v.Kind() != Invalid {
  6821  		t.Errorf("field elem: IsValid=%v, Kind=%v, want false, Invalid", v.IsValid(), v.Kind())
  6822  	}
  6823  }
  6824  
  6825  // Issue 8917.
  6826  func TestLargeGCProg(t *testing.T) {
  6827  	fv := ValueOf(func([256]*byte) {})
  6828  	fv.Call([]Value{ValueOf([256]*byte{})})
  6829  }
  6830  
  6831  func fieldIndexRecover(t Type, i int) (recovered any) {
  6832  	defer func() {
  6833  		recovered = recover()
  6834  	}()
  6835  
  6836  	t.Field(i)
  6837  	return
  6838  }
  6839  
  6840  // Issue 15046.
  6841  func TestTypeFieldOutOfRangePanic(t *testing.T) {
  6842  	typ := TypeOf(struct{ X int }{10})
  6843  	testIndices := [...]struct {
  6844  		i         int
  6845  		mustPanic bool
  6846  	}{
  6847  		0: {-2, true},
  6848  		1: {0, false},
  6849  		2: {1, true},
  6850  		3: {1 << 10, true},
  6851  	}
  6852  	for i, tt := range testIndices {
  6853  		recoveredErr := fieldIndexRecover(typ, tt.i)
  6854  		if tt.mustPanic {
  6855  			if recoveredErr == nil {
  6856  				t.Errorf("#%d: fieldIndex %d expected to panic", i, tt.i)
  6857  			}
  6858  		} else {
  6859  			if recoveredErr != nil {
  6860  				t.Errorf("#%d: got err=%v, expected no panic", i, recoveredErr)
  6861  			}
  6862  		}
  6863  	}
  6864  }
  6865  
  6866  // Issue 9179.
  6867  func TestCallGC(t *testing.T) {
  6868  	f := func(a, b, c, d, e string) {
  6869  	}
  6870  	g := func(in []Value) []Value {
  6871  		runtime.GC()
  6872  		return nil
  6873  	}
  6874  	typ := ValueOf(f).Type()
  6875  	f2 := MakeFunc(typ, g).Interface().(func(string, string, string, string, string))
  6876  	f2("four", "five5", "six666", "seven77", "eight888")
  6877  }
  6878  
  6879  // Issue 18635 (function version).
  6880  func TestKeepFuncLive(t *testing.T) {
  6881  	// Test that we keep makeFuncImpl live as long as it is
  6882  	// referenced on the stack.
  6883  	typ := TypeOf(func(i int) {})
  6884  	var f, g func(in []Value) []Value
  6885  	f = func(in []Value) []Value {
  6886  		clobber()
  6887  		i := int(in[0].Int())
  6888  		if i > 0 {
  6889  			// We can't use Value.Call here because
  6890  			// runtime.call* will keep the makeFuncImpl
  6891  			// alive. However, by converting it to an
  6892  			// interface value and calling that,
  6893  			// reflect.callReflect is the only thing that
  6894  			// can keep the makeFuncImpl live.
  6895  			//
  6896  			// Alternate between f and g so that if we do
  6897  			// reuse the memory prematurely it's more
  6898  			// likely to get obviously corrupted.
  6899  			MakeFunc(typ, g).Interface().(func(i int))(i - 1)
  6900  		}
  6901  		return nil
  6902  	}
  6903  	g = func(in []Value) []Value {
  6904  		clobber()
  6905  		i := int(in[0].Int())
  6906  		MakeFunc(typ, f).Interface().(func(i int))(i)
  6907  		return nil
  6908  	}
  6909  	MakeFunc(typ, f).Call([]Value{ValueOf(10)})
  6910  }
  6911  
  6912  type UnExportedFirst int
  6913  
  6914  func (i UnExportedFirst) ΦExported()  {}
  6915  func (i UnExportedFirst) unexported() {}
  6916  
  6917  // Issue 21177
  6918  func TestMethodByNameUnExportedFirst(t *testing.T) {
  6919  	defer func() {
  6920  		if recover() != nil {
  6921  			t.Errorf("should not panic")
  6922  		}
  6923  	}()
  6924  	typ := TypeOf(UnExportedFirst(0))
  6925  	m, _ := typ.MethodByName("ΦExported")
  6926  	if m.Name != "ΦExported" {
  6927  		t.Errorf("got %s, expected ΦExported", m.Name)
  6928  	}
  6929  }
  6930  
  6931  // Issue 18635 (method version).
  6932  type KeepMethodLive struct{}
  6933  
  6934  func (k KeepMethodLive) Method1(i int) {
  6935  	clobber()
  6936  	if i > 0 {
  6937  		ValueOf(k).MethodByName("Method2").Interface().(func(i int))(i - 1)
  6938  	}
  6939  }
  6940  
  6941  func (k KeepMethodLive) Method2(i int) {
  6942  	clobber()
  6943  	ValueOf(k).MethodByName("Method1").Interface().(func(i int))(i)
  6944  }
  6945  
  6946  func TestKeepMethodLive(t *testing.T) {
  6947  	// Test that we keep methodValue live as long as it is
  6948  	// referenced on the stack.
  6949  	KeepMethodLive{}.Method1(10)
  6950  }
  6951  
  6952  // clobber tries to clobber unreachable memory.
  6953  func clobber() {
  6954  	runtime.GC()
  6955  	for i := 1; i < 32; i++ {
  6956  		for j := 0; j < 10; j++ {
  6957  			obj := make([]*byte, i)
  6958  			sink = obj
  6959  		}
  6960  	}
  6961  	runtime.GC()
  6962  }
  6963  
  6964  func TestFuncLayout(t *testing.T) {
  6965  	align := func(x uintptr) uintptr {
  6966  		return (x + goarch.PtrSize - 1) &^ (goarch.PtrSize - 1)
  6967  	}
  6968  	var r []byte
  6969  	if goarch.PtrSize == 4 {
  6970  		r = []byte{0, 0, 0, 1}
  6971  	} else {
  6972  		r = []byte{0, 0, 1}
  6973  	}
  6974  
  6975  	type S struct {
  6976  		a, b uintptr
  6977  		c, d *byte
  6978  	}
  6979  
  6980  	type test struct {
  6981  		rcvr, typ                  Type
  6982  		size, argsize, retOffset   uintptr
  6983  		stack, gc, inRegs, outRegs []byte // pointer bitmap: 1 is pointer, 0 is scalar
  6984  		intRegs, floatRegs         int
  6985  		floatRegSize               uintptr
  6986  	}
  6987  	tests := []test{
  6988  		{
  6989  			typ:       ValueOf(func(a, b string) string { return "" }).Type(),
  6990  			size:      6 * goarch.PtrSize,
  6991  			argsize:   4 * goarch.PtrSize,
  6992  			retOffset: 4 * goarch.PtrSize,
  6993  			stack:     []byte{1, 0, 1, 0, 1},
  6994  			gc:        []byte{1, 0, 1, 0, 1},
  6995  		},
  6996  		{
  6997  			typ:       ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(),
  6998  			size:      align(align(3*4) + goarch.PtrSize + 2),
  6999  			argsize:   align(3*4) + goarch.PtrSize + 2,
  7000  			retOffset: align(align(3*4) + goarch.PtrSize + 2),
  7001  			stack:     r,
  7002  			gc:        r,
  7003  		},
  7004  		{
  7005  			typ:       ValueOf(func(a map[int]int, b uintptr, c any) {}).Type(),
  7006  			size:      4 * goarch.PtrSize,
  7007  			argsize:   4 * goarch.PtrSize,
  7008  			retOffset: 4 * goarch.PtrSize,
  7009  			stack:     []byte{1, 0, 1, 1},
  7010  			gc:        []byte{1, 0, 1, 1},
  7011  		},
  7012  		{
  7013  			typ:       ValueOf(func(a S) {}).Type(),
  7014  			size:      4 * goarch.PtrSize,
  7015  			argsize:   4 * goarch.PtrSize,
  7016  			retOffset: 4 * goarch.PtrSize,
  7017  			stack:     []byte{0, 0, 1, 1},
  7018  			gc:        []byte{0, 0, 1, 1},
  7019  		},
  7020  		{
  7021  			rcvr:      ValueOf((*byte)(nil)).Type(),
  7022  			typ:       ValueOf(func(a uintptr, b *int) {}).Type(),
  7023  			size:      3 * goarch.PtrSize,
  7024  			argsize:   3 * goarch.PtrSize,
  7025  			retOffset: 3 * goarch.PtrSize,
  7026  			stack:     []byte{1, 0, 1},
  7027  			gc:        []byte{1, 0, 1},
  7028  		},
  7029  		{
  7030  			typ:       ValueOf(func(a uintptr) {}).Type(),
  7031  			size:      goarch.PtrSize,
  7032  			argsize:   goarch.PtrSize,
  7033  			retOffset: goarch.PtrSize,
  7034  			stack:     []byte{},
  7035  			gc:        []byte{},
  7036  		},
  7037  		{
  7038  			typ:       ValueOf(func() uintptr { return 0 }).Type(),
  7039  			size:      goarch.PtrSize,
  7040  			argsize:   0,
  7041  			retOffset: 0,
  7042  			stack:     []byte{},
  7043  			gc:        []byte{},
  7044  		},
  7045  		{
  7046  			rcvr:      ValueOf(uintptr(0)).Type(),
  7047  			typ:       ValueOf(func(a uintptr) {}).Type(),
  7048  			size:      2 * goarch.PtrSize,
  7049  			argsize:   2 * goarch.PtrSize,
  7050  			retOffset: 2 * goarch.PtrSize,
  7051  			stack:     []byte{1},
  7052  			gc:        []byte{1},
  7053  			// Note: this one is tricky, as the receiver is not a pointer. But we
  7054  			// pass the receiver by reference to the autogenerated pointer-receiver
  7055  			// version of the function.
  7056  		},
  7057  		// TODO(mknyszek): Add tests for non-zero register count.
  7058  	}
  7059  	for _, lt := range tests {
  7060  		name := lt.typ.String()
  7061  		if lt.rcvr != nil {
  7062  			name = lt.rcvr.String() + "." + name
  7063  		}
  7064  		t.Run(name, func(t *testing.T) {
  7065  			defer SetArgRegs(SetArgRegs(lt.intRegs, lt.floatRegs, lt.floatRegSize))
  7066  
  7067  			typ, argsize, retOffset, stack, gc, inRegs, outRegs, ptrs := FuncLayout(lt.typ, lt.rcvr)
  7068  			if typ.Size() != lt.size {
  7069  				t.Errorf("funcLayout(%v, %v).size=%d, want %d", lt.typ, lt.rcvr, typ.Size(), lt.size)
  7070  			}
  7071  			if argsize != lt.argsize {
  7072  				t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.typ, lt.rcvr, argsize, lt.argsize)
  7073  			}
  7074  			if retOffset != lt.retOffset {
  7075  				t.Errorf("funcLayout(%v, %v).retOffset=%d, want %d", lt.typ, lt.rcvr, retOffset, lt.retOffset)
  7076  			}
  7077  			if !bytes.Equal(stack, lt.stack) {
  7078  				t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.typ, lt.rcvr, stack, lt.stack)
  7079  			}
  7080  			if !bytes.Equal(gc, lt.gc) {
  7081  				t.Errorf("funcLayout(%v, %v).gc=%v, want %v", lt.typ, lt.rcvr, gc, lt.gc)
  7082  			}
  7083  			if !bytes.Equal(inRegs, lt.inRegs) {
  7084  				t.Errorf("funcLayout(%v, %v).inRegs=%v, want %v", lt.typ, lt.rcvr, inRegs, lt.inRegs)
  7085  			}
  7086  			if !bytes.Equal(outRegs, lt.outRegs) {
  7087  				t.Errorf("funcLayout(%v, %v).outRegs=%v, want %v", lt.typ, lt.rcvr, outRegs, lt.outRegs)
  7088  			}
  7089  			if ptrs && len(stack) == 0 || !ptrs && len(stack) > 0 {
  7090  				t.Errorf("funcLayout(%v, %v) pointers flag=%v, want %v", lt.typ, lt.rcvr, ptrs, !ptrs)
  7091  			}
  7092  		})
  7093  	}
  7094  }
  7095  
  7096  // trimBitmap removes trailing 0 elements from b and returns the result.
  7097  func trimBitmap(b []byte) []byte {
  7098  	for len(b) > 0 && b[len(b)-1] == 0 {
  7099  		b = b[:len(b)-1]
  7100  	}
  7101  	return b
  7102  }
  7103  
  7104  func verifyGCBits(t *testing.T, typ Type, bits []byte) {
  7105  	heapBits := GCBits(New(typ).Interface())
  7106  
  7107  	// Trim scalars at the end, as bits might end in zero,
  7108  	// e.g. with rep(2, lit(1, 0)).
  7109  	bits = trimBitmap(bits)
  7110  
  7111  	if bytes.HasPrefix(heapBits, bits) {
  7112  		// Just the prefix matching is OK.
  7113  		//
  7114  		// The Go runtime's pointer/scalar iterator generates pointers beyond
  7115  		// the size of the type, up to the size of the size class. This space
  7116  		// is safe for the GC to scan since it's zero, and GCBits checks to
  7117  		// make sure that's true. But we need to handle the fact that the bitmap
  7118  		// may be larger than we expect.
  7119  		return
  7120  	}
  7121  	_, _, line, _ := runtime.Caller(1)
  7122  	t.Errorf("line %d: heapBits incorrect for %v\nhave %v\nwant %v", line, typ, heapBits, bits)
  7123  }
  7124  
  7125  func verifyGCBitsSlice(t *testing.T, typ Type, cap int, bits []byte) {
  7126  	// Creating a slice causes the runtime to repeat a bitmap,
  7127  	// which exercises a different path from making the compiler
  7128  	// repeat a bitmap for a small array or executing a repeat in
  7129  	// a GC program.
  7130  	val := MakeSlice(typ, 0, cap)
  7131  	data := NewAt(typ.Elem(), val.UnsafePointer())
  7132  	heapBits := GCBits(data.Interface())
  7133  	// Repeat the bitmap for the slice size, trimming scalars in
  7134  	// the last element.
  7135  	bits = trimBitmap(rep(cap, bits))
  7136  	if bytes.Equal(heapBits, bits) {
  7137  		return
  7138  	}
  7139  	if len(heapBits) > len(bits) && bytes.Equal(heapBits[:len(bits)], bits) {
  7140  		// Just the prefix matching is OK.
  7141  		return
  7142  	}
  7143  	_, _, line, _ := runtime.Caller(1)
  7144  	t.Errorf("line %d: heapBits incorrect for make(%v, 0, %v)\nhave %v\nwant %v", line, typ, cap, heapBits, bits)
  7145  }
  7146  
  7147  func TestGCBits(t *testing.T) {
  7148  	verifyGCBits(t, TypeOf((*byte)(nil)), []byte{1})
  7149  
  7150  	// Building blocks for types seen by the compiler (like [2]Xscalar).
  7151  	// The compiler will create the type structures for the derived types,
  7152  	// including their GC metadata.
  7153  	type Xscalar struct{ x uintptr }
  7154  	type Xptr struct{ x *byte }
  7155  	type Xptrscalar struct {
  7156  		*byte
  7157  		uintptr
  7158  	}
  7159  	type Xscalarptr struct {
  7160  		uintptr
  7161  		*byte
  7162  	}
  7163  	type Xbigptrscalar struct {
  7164  		_ [100]*byte
  7165  		_ [100]uintptr
  7166  	}
  7167  
  7168  	var Tscalar, Tint64, Tptr, Tscalarptr, Tptrscalar, Tbigptrscalar Type
  7169  	{
  7170  		// Building blocks for types constructed by reflect.
  7171  		// This code is in a separate block so that code below
  7172  		// cannot accidentally refer to these.
  7173  		// The compiler must NOT see types derived from these
  7174  		// (for example, [2]Scalar must NOT appear in the program),
  7175  		// or else reflect will use it instead of having to construct one.
  7176  		// The goal is to test the construction.
  7177  		type Scalar struct{ x uintptr }
  7178  		type Ptr struct{ x *byte }
  7179  		type Ptrscalar struct {
  7180  			*byte
  7181  			uintptr
  7182  		}
  7183  		type Scalarptr struct {
  7184  			uintptr
  7185  			*byte
  7186  		}
  7187  		type Bigptrscalar struct {
  7188  			_ [100]*byte
  7189  			_ [100]uintptr
  7190  		}
  7191  		type Int64 int64
  7192  		Tscalar = TypeOf(Scalar{})
  7193  		Tint64 = TypeOf(Int64(0))
  7194  		Tptr = TypeOf(Ptr{})
  7195  		Tscalarptr = TypeOf(Scalarptr{})
  7196  		Tptrscalar = TypeOf(Ptrscalar{})
  7197  		Tbigptrscalar = TypeOf(Bigptrscalar{})
  7198  	}
  7199  
  7200  	empty := []byte{}
  7201  
  7202  	verifyGCBits(t, TypeOf(Xscalar{}), empty)
  7203  	verifyGCBits(t, Tscalar, empty)
  7204  	verifyGCBits(t, TypeOf(Xptr{}), lit(1))
  7205  	verifyGCBits(t, Tptr, lit(1))
  7206  	verifyGCBits(t, TypeOf(Xscalarptr{}), lit(0, 1))
  7207  	verifyGCBits(t, Tscalarptr, lit(0, 1))
  7208  	verifyGCBits(t, TypeOf(Xptrscalar{}), lit(1))
  7209  	verifyGCBits(t, Tptrscalar, lit(1))
  7210  
  7211  	verifyGCBits(t, TypeOf([0]Xptr{}), empty)
  7212  	verifyGCBits(t, ArrayOf(0, Tptr), empty)
  7213  	verifyGCBits(t, TypeOf([1]Xptrscalar{}), lit(1))
  7214  	verifyGCBits(t, ArrayOf(1, Tptrscalar), lit(1))
  7215  	verifyGCBits(t, TypeOf([2]Xscalar{}), empty)
  7216  	verifyGCBits(t, ArrayOf(2, Tscalar), empty)
  7217  	verifyGCBits(t, TypeOf([10000]Xscalar{}), empty)
  7218  	verifyGCBits(t, ArrayOf(10000, Tscalar), empty)
  7219  	verifyGCBits(t, TypeOf([2]Xptr{}), lit(1, 1))
  7220  	verifyGCBits(t, ArrayOf(2, Tptr), lit(1, 1))
  7221  	verifyGCBits(t, TypeOf([10000]Xptr{}), rep(10000, lit(1)))
  7222  	verifyGCBits(t, ArrayOf(10000, Tptr), rep(10000, lit(1)))
  7223  	verifyGCBits(t, TypeOf([2]Xscalarptr{}), lit(0, 1, 0, 1))
  7224  	verifyGCBits(t, ArrayOf(2, Tscalarptr), lit(0, 1, 0, 1))
  7225  	verifyGCBits(t, TypeOf([10000]Xscalarptr{}), rep(10000, lit(0, 1)))
  7226  	verifyGCBits(t, ArrayOf(10000, Tscalarptr), rep(10000, lit(0, 1)))
  7227  	verifyGCBits(t, TypeOf([2]Xptrscalar{}), lit(1, 0, 1))
  7228  	verifyGCBits(t, ArrayOf(2, Tptrscalar), lit(1, 0, 1))
  7229  	verifyGCBits(t, TypeOf([10000]Xptrscalar{}), rep(10000, lit(1, 0)))
  7230  	verifyGCBits(t, ArrayOf(10000, Tptrscalar), rep(10000, lit(1, 0)))
  7231  	verifyGCBits(t, TypeOf([1][10000]Xptrscalar{}), rep(10000, lit(1, 0)))
  7232  	verifyGCBits(t, ArrayOf(1, ArrayOf(10000, Tptrscalar)), rep(10000, lit(1, 0)))
  7233  	verifyGCBits(t, TypeOf([2][10000]Xptrscalar{}), rep(2*10000, lit(1, 0)))
  7234  	verifyGCBits(t, ArrayOf(2, ArrayOf(10000, Tptrscalar)), rep(2*10000, lit(1, 0)))
  7235  	verifyGCBits(t, TypeOf([4]Xbigptrscalar{}), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
  7236  	verifyGCBits(t, ArrayOf(4, Tbigptrscalar), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
  7237  
  7238  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 0, empty)
  7239  	verifyGCBitsSlice(t, SliceOf(Tptr), 0, empty)
  7240  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 1, lit(1))
  7241  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 1, lit(1))
  7242  	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 2, lit(0))
  7243  	verifyGCBitsSlice(t, SliceOf(Tscalar), 2, lit(0))
  7244  	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 10000, lit(0))
  7245  	verifyGCBitsSlice(t, SliceOf(Tscalar), 10000, lit(0))
  7246  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 2, lit(1))
  7247  	verifyGCBitsSlice(t, SliceOf(Tptr), 2, lit(1))
  7248  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 10000, lit(1))
  7249  	verifyGCBitsSlice(t, SliceOf(Tptr), 10000, lit(1))
  7250  	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 2, lit(0, 1))
  7251  	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 2, lit(0, 1))
  7252  	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 10000, lit(0, 1))
  7253  	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 10000, lit(0, 1))
  7254  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 2, lit(1, 0))
  7255  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 2, lit(1, 0))
  7256  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 10000, lit(1, 0))
  7257  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 10000, lit(1, 0))
  7258  	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 1, rep(10000, lit(1, 0)))
  7259  	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 1, rep(10000, lit(1, 0)))
  7260  	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 2, rep(10000, lit(1, 0)))
  7261  	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 2, rep(10000, lit(1, 0)))
  7262  	verifyGCBitsSlice(t, TypeOf([]Xbigptrscalar{}), 4, join(rep(100, lit(1)), rep(100, lit(0))))
  7263  	verifyGCBitsSlice(t, SliceOf(Tbigptrscalar), 4, join(rep(100, lit(1)), rep(100, lit(0))))
  7264  
  7265  	verifyGCBits(t, TypeOf((chan [100]Xscalar)(nil)), lit(1))
  7266  	verifyGCBits(t, ChanOf(BothDir, ArrayOf(100, Tscalar)), lit(1))
  7267  
  7268  	verifyGCBits(t, TypeOf((func([10000]Xscalarptr))(nil)), lit(1))
  7269  	verifyGCBits(t, FuncOf([]Type{ArrayOf(10000, Tscalarptr)}, nil, false), lit(1))
  7270  
  7271  	verifyGCBits(t, TypeOf((map[[10000]Xscalarptr]Xscalar)(nil)), lit(1))
  7272  	verifyGCBits(t, MapOf(ArrayOf(10000, Tscalarptr), Tscalar), lit(1))
  7273  
  7274  	verifyGCBits(t, TypeOf((*[10000]Xscalar)(nil)), lit(1))
  7275  	verifyGCBits(t, PointerTo(ArrayOf(10000, Tscalar)), lit(1))
  7276  
  7277  	verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
  7278  	verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))
  7279  
  7280  	hdr := make([]byte, bucketCount/goarch.PtrSize)
  7281  
  7282  	verifyMapBucket := func(t *testing.T, k, e Type, m any, want []byte) {
  7283  		verifyGCBits(t, MapBucketOf(k, e), want)
  7284  		verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
  7285  	}
  7286  	verifyMapBucket(t,
  7287  		Tscalar, Tptr,
  7288  		map[Xscalar]Xptr(nil),
  7289  		join(hdr, rep(bucketCount, lit(0)), rep(bucketCount, lit(1)), lit(1)))
  7290  	verifyMapBucket(t,
  7291  		Tscalarptr, Tptr,
  7292  		map[Xscalarptr]Xptr(nil),
  7293  		join(hdr, rep(bucketCount, lit(0, 1)), rep(bucketCount, lit(1)), lit(1)))
  7294  	verifyMapBucket(t, Tint64, Tptr,
  7295  		map[int64]Xptr(nil),
  7296  		join(hdr, rep(bucketCount, rep(8/goarch.PtrSize, lit(0))), rep(bucketCount, lit(1)), lit(1)))
  7297  	verifyMapBucket(t,
  7298  		Tscalar, Tscalar,
  7299  		map[Xscalar]Xscalar(nil),
  7300  		empty)
  7301  	verifyMapBucket(t,
  7302  		ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
  7303  		map[[2]Xscalarptr][3]Xptrscalar(nil),
  7304  		join(hdr, rep(bucketCount*2, lit(0, 1)), rep(bucketCount*3, lit(1, 0)), lit(1)))
  7305  	verifyMapBucket(t,
  7306  		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
  7307  		map[[64 / goarch.PtrSize]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
  7308  		join(hdr, rep(bucketCount*64/goarch.PtrSize, lit(0, 1)), rep(bucketCount*64/goarch.PtrSize, lit(1, 0)), lit(1)))
  7309  	verifyMapBucket(t,
  7310  		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
  7311  		map[[64/goarch.PtrSize + 1]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
  7312  		join(hdr, rep(bucketCount, lit(1)), rep(bucketCount*64/goarch.PtrSize, lit(1, 0)), lit(1)))
  7313  	verifyMapBucket(t,
  7314  		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
  7315  		map[[64 / goarch.PtrSize]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
  7316  		join(hdr, rep(bucketCount*64/goarch.PtrSize, lit(0, 1)), rep(bucketCount, lit(1)), lit(1)))
  7317  	verifyMapBucket(t,
  7318  		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
  7319  		map[[64/goarch.PtrSize + 1]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
  7320  		join(hdr, rep(bucketCount, lit(1)), rep(bucketCount, lit(1)), lit(1)))
  7321  }
  7322  
  7323  func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) }
  7324  func join(b ...[]byte) []byte    { return bytes.Join(b, nil) }
  7325  func lit(x ...byte) []byte       { return x }
  7326  
  7327  func TestTypeOfTypeOf(t *testing.T) {
  7328  	// Check that all the type constructors return concrete *rtype implementations.
  7329  	// It's difficult to test directly because the reflect package is only at arm's length.
  7330  	// The easiest thing to do is just call a function that crashes if it doesn't get an *rtype.
  7331  	check := func(name string, typ Type) {
  7332  		if underlying := TypeOf(typ).String(); underlying != "*reflect.rtype" {
  7333  			t.Errorf("%v returned %v, not *reflect.rtype", name, underlying)
  7334  		}
  7335  	}
  7336  
  7337  	type T struct{ int }
  7338  	check("TypeOf", TypeOf(T{}))
  7339  
  7340  	check("ArrayOf", ArrayOf(10, TypeOf(T{})))
  7341  	check("ChanOf", ChanOf(BothDir, TypeOf(T{})))
  7342  	check("FuncOf", FuncOf([]Type{TypeOf(T{})}, nil, false))
  7343  	check("MapOf", MapOf(TypeOf(T{}), TypeOf(T{})))
  7344  	check("PtrTo", PointerTo(TypeOf(T{})))
  7345  	check("SliceOf", SliceOf(TypeOf(T{})))
  7346  }
  7347  
  7348  type XM struct{ _ bool }
  7349  
  7350  func (*XM) String() string { return "" }
  7351  
  7352  func TestPtrToMethods(t *testing.T) {
  7353  	var y struct{ XM }
  7354  	yp := New(TypeOf(y)).Interface()
  7355  	_, ok := yp.(fmt.Stringer)
  7356  	if !ok {
  7357  		t.Fatal("does not implement Stringer, but should")
  7358  	}
  7359  }
  7360  
  7361  func TestMapAlloc(t *testing.T) {
  7362  	m := ValueOf(make(map[int]int, 10))
  7363  	k := ValueOf(5)
  7364  	v := ValueOf(7)
  7365  	allocs := testing.AllocsPerRun(100, func() {
  7366  		m.SetMapIndex(k, v)
  7367  	})
  7368  	if allocs > 0.5 {
  7369  		t.Errorf("allocs per map assignment: want 0 got %f", allocs)
  7370  	}
  7371  
  7372  	const size = 1000
  7373  	tmp := 0
  7374  	val := ValueOf(&tmp).Elem()
  7375  	allocs = testing.AllocsPerRun(100, func() {
  7376  		mv := MakeMapWithSize(TypeOf(map[int]int{}), size)
  7377  		// Only adding half of the capacity to not trigger re-allocations due too many overloaded buckets.
  7378  		for i := 0; i < size/2; i++ {
  7379  			val.SetInt(int64(i))
  7380  			mv.SetMapIndex(val, val)
  7381  		}
  7382  	})
  7383  	if allocs > 10 {
  7384  		t.Errorf("allocs per map assignment: want at most 10 got %f", allocs)
  7385  	}
  7386  	// Empirical testing shows that with capacity hint single run will trigger 3 allocations and without 91. I set
  7387  	// the threshold to 10, to not make it overly brittle if something changes in the initial allocation of the
  7388  	// map, but to still catch a regression where we keep re-allocating in the hashmap as new entries are added.
  7389  }
  7390  
  7391  func TestChanAlloc(t *testing.T) {
  7392  	// Note: for a chan int, the return Value must be allocated, so we
  7393  	// use a chan *int instead.
  7394  	c := ValueOf(make(chan *int, 1))
  7395  	v := ValueOf(new(int))
  7396  	allocs := testing.AllocsPerRun(100, func() {
  7397  		c.Send(v)
  7398  		_, _ = c.Recv()
  7399  	})
  7400  	if allocs < 0.5 || allocs > 1.5 {
  7401  		t.Errorf("allocs per chan send/recv: want 1 got %f", allocs)
  7402  	}
  7403  	// Note: there is one allocation in reflect.recv which seems to be
  7404  	// a limitation of escape analysis. If that is ever fixed the
  7405  	// allocs < 0.5 condition will trigger and this test should be fixed.
  7406  }
  7407  
  7408  type TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678 int
  7409  
  7410  type nameTest struct {
  7411  	v    any
  7412  	want string
  7413  }
  7414  
  7415  var nameTests = []nameTest{
  7416  	{(*int32)(nil), "int32"},
  7417  	{(*D1)(nil), "D1"},
  7418  	{(*[]D1)(nil), ""},
  7419  	{(*chan D1)(nil), ""},
  7420  	{(*func() D1)(nil), ""},
  7421  	{(*<-chan D1)(nil), ""},
  7422  	{(*chan<- D1)(nil), ""},
  7423  	{(*any)(nil), ""},
  7424  	{(*interface {
  7425  		F()
  7426  	})(nil), ""},
  7427  	{(*TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678)(nil), "TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678"},
  7428  }
  7429  
  7430  func TestNames(t *testing.T) {
  7431  	for _, test := range nameTests {
  7432  		typ := TypeOf(test.v).Elem()
  7433  		if got := typ.Name(); got != test.want {
  7434  			t.Errorf("%v Name()=%q, want %q", typ, got, test.want)
  7435  		}
  7436  	}
  7437  }
  7438  
  7439  func TestExported(t *testing.T) {
  7440  	type ΦExported struct{}
  7441  	type φUnexported struct{}
  7442  	type BigP *big
  7443  	type P int
  7444  	type p *P
  7445  	type P2 p
  7446  	type p3 p
  7447  
  7448  	type exportTest struct {
  7449  		v    any
  7450  		want bool
  7451  	}
  7452  	exportTests := []exportTest{
  7453  		{D1{}, true},
  7454  		{(*D1)(nil), true},
  7455  		{big{}, false},
  7456  		{(*big)(nil), false},
  7457  		{(BigP)(nil), true},
  7458  		{(*BigP)(nil), true},
  7459  		{ΦExported{}, true},
  7460  		{φUnexported{}, false},
  7461  		{P(0), true},
  7462  		{(p)(nil), false},
  7463  		{(P2)(nil), true},
  7464  		{(p3)(nil), false},
  7465  	}
  7466  
  7467  	for i, test := range exportTests {
  7468  		typ := TypeOf(test.v)
  7469  		if got := IsExported(typ); got != test.want {
  7470  			t.Errorf("%d: %s exported=%v, want %v", i, typ.Name(), got, test.want)
  7471  		}
  7472  	}
  7473  }
  7474  
  7475  func TestTypeStrings(t *testing.T) {
  7476  	type stringTest struct {
  7477  		typ  Type
  7478  		want string
  7479  	}
  7480  	stringTests := []stringTest{
  7481  		{TypeOf(func(int) {}), "func(int)"},
  7482  		{FuncOf([]Type{TypeOf(int(0))}, nil, false), "func(int)"},
  7483  		{TypeOf(XM{}), "reflect_test.XM"},
  7484  		{TypeOf(new(XM)), "*reflect_test.XM"},
  7485  		{TypeOf(new(XM).String), "func() string"},
  7486  		{TypeOf(new(XM)).Method(0).Type, "func(*reflect_test.XM) string"},
  7487  		{ChanOf(3, TypeOf(XM{})), "chan reflect_test.XM"},
  7488  		{MapOf(TypeOf(int(0)), TypeOf(XM{})), "map[int]reflect_test.XM"},
  7489  		{ArrayOf(3, TypeOf(XM{})), "[3]reflect_test.XM"},
  7490  		{ArrayOf(3, TypeOf(struct{}{})), "[3]struct {}"},
  7491  	}
  7492  
  7493  	for i, test := range stringTests {
  7494  		if got, want := test.typ.String(), test.want; got != want {
  7495  			t.Errorf("type %d String()=%q, want %q", i, got, want)
  7496  		}
  7497  	}
  7498  }
  7499  
  7500  func TestOffsetLock(t *testing.T) {
  7501  	var wg sync.WaitGroup
  7502  	for i := 0; i < 4; i++ {
  7503  		i := i
  7504  		wg.Add(1)
  7505  		go func() {
  7506  			for j := 0; j < 50; j++ {
  7507  				ResolveReflectName(fmt.Sprintf("OffsetLockName:%d:%d", i, j))
  7508  			}
  7509  			wg.Done()
  7510  		}()
  7511  	}
  7512  	wg.Wait()
  7513  }
  7514  
  7515  func TestSwapper(t *testing.T) {
  7516  	type I int
  7517  	var a, b, c I
  7518  	type pair struct {
  7519  		x, y int
  7520  	}
  7521  	type pairPtr struct {
  7522  		x, y int
  7523  		p    *I
  7524  	}
  7525  	type S string
  7526  
  7527  	tests := []struct {
  7528  		in   any
  7529  		i, j int
  7530  		want any
  7531  	}{
  7532  		{
  7533  			in:   []int{1, 20, 300},
  7534  			i:    0,
  7535  			j:    2,
  7536  			want: []int{300, 20, 1},
  7537  		},
  7538  		{
  7539  			in:   []uintptr{1, 20, 300},
  7540  			i:    0,
  7541  			j:    2,
  7542  			want: []uintptr{300, 20, 1},
  7543  		},
  7544  		{
  7545  			in:   []int16{1, 20, 300},
  7546  			i:    0,
  7547  			j:    2,
  7548  			want: []int16{300, 20, 1},
  7549  		},
  7550  		{
  7551  			in:   []int8{1, 20, 100},
  7552  			i:    0,
  7553  			j:    2,
  7554  			want: []int8{100, 20, 1},
  7555  		},
  7556  		{
  7557  			in:   []*I{&a, &b, &c},
  7558  			i:    0,
  7559  			j:    2,
  7560  			want: []*I{&c, &b, &a},
  7561  		},
  7562  		{
  7563  			in:   []string{"eric", "sergey", "larry"},
  7564  			i:    0,
  7565  			j:    2,
  7566  			want: []string{"larry", "sergey", "eric"},
  7567  		},
  7568  		{
  7569  			in:   []S{"eric", "sergey", "larry"},
  7570  			i:    0,
  7571  			j:    2,
  7572  			want: []S{"larry", "sergey", "eric"},
  7573  		},
  7574  		{
  7575  			in:   []pair{{1, 2}, {3, 4}, {5, 6}},
  7576  			i:    0,
  7577  			j:    2,
  7578  			want: []pair{{5, 6}, {3, 4}, {1, 2}},
  7579  		},
  7580  		{
  7581  			in:   []pairPtr{{1, 2, &a}, {3, 4, &b}, {5, 6, &c}},
  7582  			i:    0,
  7583  			j:    2,
  7584  			want: []pairPtr{{5, 6, &c}, {3, 4, &b}, {1, 2, &a}},
  7585  		},
  7586  	}
  7587  
  7588  	for i, tt := range tests {
  7589  		inStr := fmt.Sprint(tt.in)
  7590  		Swapper(tt.in)(tt.i, tt.j)
  7591  		if !DeepEqual(tt.in, tt.want) {
  7592  			t.Errorf("%d. swapping %v and %v of %v = %v; want %v", i, tt.i, tt.j, inStr, tt.in, tt.want)
  7593  		}
  7594  	}
  7595  }
  7596  
  7597  // TestUnaddressableField tests that the reflect package will not allow
  7598  // a type from another package to be used as a named type with an
  7599  // unexported field.
  7600  //
  7601  // This ensures that unexported fields cannot be modified by other packages.
  7602  func TestUnaddressableField(t *testing.T) {
  7603  	var b Buffer // type defined in reflect, a different package
  7604  	var localBuffer struct {
  7605  		buf []byte
  7606  	}
  7607  	lv := ValueOf(&localBuffer).Elem()
  7608  	rv := ValueOf(b)
  7609  	shouldPanic("Set", func() {
  7610  		lv.Set(rv)
  7611  	})
  7612  }
  7613  
  7614  type Tint int
  7615  
  7616  type Tint2 = Tint
  7617  
  7618  type Talias1 struct {
  7619  	byte
  7620  	uint8
  7621  	int
  7622  	int32
  7623  	rune
  7624  }
  7625  
  7626  type Talias2 struct {
  7627  	Tint
  7628  	Tint2
  7629  }
  7630  
  7631  func TestAliasNames(t *testing.T) {
  7632  	t1 := Talias1{byte: 1, uint8: 2, int: 3, int32: 4, rune: 5}
  7633  	out := fmt.Sprintf("%#v", t1)
  7634  	want := "reflect_test.Talias1{byte:0x1, uint8:0x2, int:3, int32:4, rune:5}"
  7635  	if out != want {
  7636  		t.Errorf("Talias1 print:\nhave: %s\nwant: %s", out, want)
  7637  	}
  7638  
  7639  	t2 := Talias2{Tint: 1, Tint2: 2}
  7640  	out = fmt.Sprintf("%#v", t2)
  7641  	want = "reflect_test.Talias2{Tint:1, Tint2:2}"
  7642  	if out != want {
  7643  		t.Errorf("Talias2 print:\nhave: %s\nwant: %s", out, want)
  7644  	}
  7645  }
  7646  
  7647  func TestIssue22031(t *testing.T) {
  7648  	type s []struct{ C int }
  7649  
  7650  	type t1 struct{ s }
  7651  	type t2 struct{ f s }
  7652  
  7653  	tests := []Value{
  7654  		ValueOf(t1{s{{}}}).Field(0).Index(0).Field(0),
  7655  		ValueOf(t2{s{{}}}).Field(0).Index(0).Field(0),
  7656  	}
  7657  
  7658  	for i, test := range tests {
  7659  		if test.CanSet() {
  7660  			t.Errorf("%d: CanSet: got true, want false", i)
  7661  		}
  7662  	}
  7663  }
  7664  
  7665  type NonExportedFirst int
  7666  
  7667  func (i NonExportedFirst) ΦExported()       {}
  7668  func (i NonExportedFirst) nonexported() int { panic("wrong") }
  7669  
  7670  func TestIssue22073(t *testing.T) {
  7671  	m := ValueOf(NonExportedFirst(0)).Method(0)
  7672  
  7673  	if got := m.Type().NumOut(); got != 0 {
  7674  		t.Errorf("NumOut: got %v, want 0", got)
  7675  	}
  7676  
  7677  	// Shouldn't panic.
  7678  	m.Call(nil)
  7679  }
  7680  
  7681  func TestMapIterNonEmptyMap(t *testing.T) {
  7682  	m := map[string]int{"one": 1, "two": 2, "three": 3}
  7683  	iter := ValueOf(m).MapRange()
  7684  	if got, want := iterateToString(iter), `[one: 1, three: 3, two: 2]`; got != want {
  7685  		t.Errorf("iterator returned %s (after sorting), want %s", got, want)
  7686  	}
  7687  }
  7688  
  7689  func TestMapIterNilMap(t *testing.T) {
  7690  	var m map[string]int
  7691  	iter := ValueOf(m).MapRange()
  7692  	if got, want := iterateToString(iter), `[]`; got != want {
  7693  		t.Errorf("non-empty result iteratoring nil map: %s", got)
  7694  	}
  7695  }
  7696  
  7697  func TestMapIterReset(t *testing.T) {
  7698  	iter := new(MapIter)
  7699  
  7700  	// Use of zero iterator should panic.
  7701  	func() {
  7702  		defer func() { recover() }()
  7703  		iter.Next()
  7704  		t.Error("Next did not panic")
  7705  	}()
  7706  
  7707  	// Reset to new Map should work.
  7708  	m := map[string]int{"one": 1, "two": 2, "three": 3}
  7709  	iter.Reset(ValueOf(m))
  7710  	if got, want := iterateToString(iter), `[one: 1, three: 3, two: 2]`; got != want {
  7711  		t.Errorf("iterator returned %s (after sorting), want %s", got, want)
  7712  	}
  7713  
  7714  	// Reset to Zero value should work, but iterating over it should panic.
  7715  	iter.Reset(Value{})
  7716  	func() {
  7717  		defer func() { recover() }()
  7718  		iter.Next()
  7719  		t.Error("Next did not panic")
  7720  	}()
  7721  
  7722  	// Reset to a different Map with different types should work.
  7723  	m2 := map[int]string{1: "one", 2: "two", 3: "three"}
  7724  	iter.Reset(ValueOf(m2))
  7725  	if got, want := iterateToString(iter), `[1: one, 2: two, 3: three]`; got != want {
  7726  		t.Errorf("iterator returned %s (after sorting), want %s", got, want)
  7727  	}
  7728  
  7729  	// Check that Reset, Next, and SetKey/SetValue play nicely together.
  7730  	m3 := map[uint64]uint64{
  7731  		1 << 0: 1 << 1,
  7732  		1 << 1: 1 << 2,
  7733  		1 << 2: 1 << 3,
  7734  	}
  7735  	kv := New(TypeOf(uint64(0))).Elem()
  7736  	for i := 0; i < 5; i++ {
  7737  		var seenk, seenv uint64
  7738  		iter.Reset(ValueOf(m3))
  7739  		for iter.Next() {
  7740  			kv.SetIterKey(iter)
  7741  			seenk ^= kv.Uint()
  7742  			kv.SetIterValue(iter)
  7743  			seenv ^= kv.Uint()
  7744  		}
  7745  		if seenk != 0b111 {
  7746  			t.Errorf("iteration yielded keys %b, want %b", seenk, 0b111)
  7747  		}
  7748  		if seenv != 0b1110 {
  7749  			t.Errorf("iteration yielded values %b, want %b", seenv, 0b1110)
  7750  		}
  7751  	}
  7752  
  7753  	// Reset should not allocate.
  7754  	n := int(testing.AllocsPerRun(10, func() {
  7755  		iter.Reset(ValueOf(m2))
  7756  		iter.Reset(Value{})
  7757  	}))
  7758  	if n > 0 {
  7759  		t.Errorf("MapIter.Reset allocated %d times", n)
  7760  	}
  7761  }
  7762  
  7763  func TestMapIterSafety(t *testing.T) {
  7764  	// Using a zero MapIter causes a panic, but not a crash.
  7765  	func() {
  7766  		defer func() { recover() }()
  7767  		new(MapIter).Key()
  7768  		t.Fatal("Key did not panic")
  7769  	}()
  7770  	func() {
  7771  		defer func() { recover() }()
  7772  		new(MapIter).Value()
  7773  		t.Fatal("Value did not panic")
  7774  	}()
  7775  	func() {
  7776  		defer func() { recover() }()
  7777  		new(MapIter).Next()
  7778  		t.Fatal("Next did not panic")
  7779  	}()
  7780  
  7781  	// Calling Key/Value on a MapIter before Next
  7782  	// causes a panic, but not a crash.
  7783  	var m map[string]int
  7784  	iter := ValueOf(m).MapRange()
  7785  
  7786  	func() {
  7787  		defer func() { recover() }()
  7788  		iter.Key()
  7789  		t.Fatal("Key did not panic")
  7790  	}()
  7791  	func() {
  7792  		defer func() { recover() }()
  7793  		iter.Value()
  7794  		t.Fatal("Value did not panic")
  7795  	}()
  7796  
  7797  	// Calling Next, Key, or Value on an exhausted iterator
  7798  	// causes a panic, but not a crash.
  7799  	iter.Next() // -> false
  7800  	func() {
  7801  		defer func() { recover() }()
  7802  		iter.Key()
  7803  		t.Fatal("Key did not panic")
  7804  	}()
  7805  	func() {
  7806  		defer func() { recover() }()
  7807  		iter.Value()
  7808  		t.Fatal("Value did not panic")
  7809  	}()
  7810  	func() {
  7811  		defer func() { recover() }()
  7812  		iter.Next()
  7813  		t.Fatal("Next did not panic")
  7814  	}()
  7815  }
  7816  
  7817  func TestMapIterNext(t *testing.T) {
  7818  	// The first call to Next should reflect any
  7819  	// insertions to the map since the iterator was created.
  7820  	m := map[string]int{}
  7821  	iter := ValueOf(m).MapRange()
  7822  	m["one"] = 1
  7823  	if got, want := iterateToString(iter), `[one: 1]`; got != want {
  7824  		t.Errorf("iterator returned deleted elements: got %s, want %s", got, want)
  7825  	}
  7826  }
  7827  
  7828  func TestMapIterDelete0(t *testing.T) {
  7829  	// Delete all elements before first iteration.
  7830  	m := map[string]int{"one": 1, "two": 2, "three": 3}
  7831  	iter := ValueOf(m).MapRange()
  7832  	delete(m, "one")
  7833  	delete(m, "two")
  7834  	delete(m, "three")
  7835  	if got, want := iterateToString(iter), `[]`; got != want {
  7836  		t.Errorf("iterator returned deleted elements: got %s, want %s", got, want)
  7837  	}
  7838  }
  7839  
  7840  func TestMapIterDelete1(t *testing.T) {
  7841  	// Delete all elements after first iteration.
  7842  	m := map[string]int{"one": 1, "two": 2, "three": 3}
  7843  	iter := ValueOf(m).MapRange()
  7844  	var got []string
  7845  	for iter.Next() {
  7846  		got = append(got, fmt.Sprint(iter.Key(), iter.Value()))
  7847  		delete(m, "one")
  7848  		delete(m, "two")
  7849  		delete(m, "three")
  7850  	}
  7851  	if len(got) != 1 {
  7852  		t.Errorf("iterator returned wrong number of elements: got %d, want 1", len(got))
  7853  	}
  7854  }
  7855  
  7856  // iterateToString returns the set of elements
  7857  // returned by an iterator in readable form.
  7858  func iterateToString(it *MapIter) string {
  7859  	var got []string
  7860  	for it.Next() {
  7861  		line := fmt.Sprintf("%v: %v", it.Key(), it.Value())
  7862  		got = append(got, line)
  7863  	}
  7864  	slices.Sort(got)
  7865  	return "[" + strings.Join(got, ", ") + "]"
  7866  }
  7867  
  7868  func TestConvertibleTo(t *testing.T) {
  7869  	t1 := ValueOf(example1.MyStruct{}).Type()
  7870  	t2 := ValueOf(example2.MyStruct{}).Type()
  7871  
  7872  	// Shouldn't raise stack overflow
  7873  	if t1.ConvertibleTo(t2) {
  7874  		t.Fatalf("(%s).ConvertibleTo(%s) = true, want false", t1, t2)
  7875  	}
  7876  
  7877  	t3 := ValueOf([]example1.MyStruct{}).Type()
  7878  	t4 := ValueOf([]example2.MyStruct{}).Type()
  7879  
  7880  	if t3.ConvertibleTo(t4) {
  7881  		t.Fatalf("(%s).ConvertibleTo(%s) = true, want false", t3, t4)
  7882  	}
  7883  }
  7884  
  7885  func TestSetIter(t *testing.T) {
  7886  	data := map[string]int{
  7887  		"foo": 1,
  7888  		"bar": 2,
  7889  		"baz": 3,
  7890  	}
  7891  
  7892  	m := ValueOf(data)
  7893  	i := m.MapRange()
  7894  	k := New(TypeOf("")).Elem()
  7895  	v := New(TypeOf(0)).Elem()
  7896  	shouldPanic("Value.SetIterKey called before Next", func() {
  7897  		k.SetIterKey(i)
  7898  	})
  7899  	shouldPanic("Value.SetIterValue called before Next", func() {
  7900  		v.SetIterValue(i)
  7901  	})
  7902  	data2 := map[string]int{}
  7903  	for i.Next() {
  7904  		k.SetIterKey(i)
  7905  		v.SetIterValue(i)
  7906  		data2[k.Interface().(string)] = v.Interface().(int)
  7907  	}
  7908  	if !DeepEqual(data, data2) {
  7909  		t.Errorf("maps not equal, got %v want %v", data2, data)
  7910  	}
  7911  	shouldPanic("Value.SetIterKey called on exhausted iterator", func() {
  7912  		k.SetIterKey(i)
  7913  	})
  7914  	shouldPanic("Value.SetIterValue called on exhausted iterator", func() {
  7915  		v.SetIterValue(i)
  7916  	})
  7917  
  7918  	i.Reset(m)
  7919  	i.Next()
  7920  	shouldPanic("Value.SetIterKey using unaddressable value", func() {
  7921  		ValueOf("").SetIterKey(i)
  7922  	})
  7923  	shouldPanic("Value.SetIterValue using unaddressable value", func() {
  7924  		ValueOf(0).SetIterValue(i)
  7925  	})
  7926  	shouldPanic("value of type string is not assignable to type int", func() {
  7927  		New(TypeOf(0)).Elem().SetIterKey(i)
  7928  	})
  7929  	shouldPanic("value of type int is not assignable to type string", func() {
  7930  		New(TypeOf("")).Elem().SetIterValue(i)
  7931  	})
  7932  
  7933  	// Make sure assignment conversion works.
  7934  	var x any
  7935  	y := ValueOf(&x).Elem()
  7936  	y.SetIterKey(i)
  7937  	if _, ok := data[x.(string)]; !ok {
  7938  		t.Errorf("got key %s which is not in map", x)
  7939  	}
  7940  	y.SetIterValue(i)
  7941  	if x.(int) < 1 || x.(int) > 3 {
  7942  		t.Errorf("got value %d which is not in map", x)
  7943  	}
  7944  
  7945  	// Try some key/value types which are direct interfaces.
  7946  	a := 88
  7947  	b := 99
  7948  	pp := map[*int]*int{
  7949  		&a: &b,
  7950  	}
  7951  	i = ValueOf(pp).MapRange()
  7952  	i.Next()
  7953  	y.SetIterKey(i)
  7954  	if got := *y.Interface().(*int); got != a {
  7955  		t.Errorf("pointer incorrect: got %d want %d", got, a)
  7956  	}
  7957  	y.SetIterValue(i)
  7958  	if got := *y.Interface().(*int); got != b {
  7959  		t.Errorf("pointer incorrect: got %d want %d", got, b)
  7960  	}
  7961  
  7962  	// Make sure we panic assigning from an unexported field.
  7963  	m = ValueOf(struct{ m map[string]int }{data}).Field(0)
  7964  	for iter := m.MapRange(); iter.Next(); {
  7965  		shouldPanic("using value obtained using unexported field", func() {
  7966  			k.SetIterKey(iter)
  7967  		})
  7968  		shouldPanic("using value obtained using unexported field", func() {
  7969  			v.SetIterValue(iter)
  7970  		})
  7971  	}
  7972  }
  7973  
  7974  func TestMethodCallValueCodePtr(t *testing.T) {
  7975  	m := ValueOf(Point{}).Method(1)
  7976  	want := MethodValueCallCodePtr()
  7977  	if got := uintptr(m.UnsafePointer()); got != want {
  7978  		t.Errorf("methodValueCall code pointer mismatched, want: %v, got: %v", want, got)
  7979  	}
  7980  	if got := m.Pointer(); got != want {
  7981  		t.Errorf("methodValueCall code pointer mismatched, want: %v, got: %v", want, got)
  7982  	}
  7983  }
  7984  
  7985  type A struct{}
  7986  type B[T any] struct{}
  7987  
  7988  func TestIssue50208(t *testing.T) {
  7989  	want1 := "B[reflect_test.A]"
  7990  	if got := TypeOf(new(B[A])).Elem().Name(); got != want1 {
  7991  		t.Errorf("name of type parameter mismatched, want:%s, got:%s", want1, got)
  7992  	}
  7993  	want2 := "B[reflect_test.B[reflect_test.A]]"
  7994  	if got := TypeOf(new(B[B[A]])).Elem().Name(); got != want2 {
  7995  		t.Errorf("name of type parameter mismatched, want:%s, got:%s", want2, got)
  7996  	}
  7997  }
  7998  
  7999  func TestNegativeKindString(t *testing.T) {
  8000  	x := -1
  8001  	s := Kind(x).String()
  8002  	want := "kind-1"
  8003  	if s != want {
  8004  		t.Fatalf("Kind(-1).String() = %q, want %q", s, want)
  8005  	}
  8006  }
  8007  
  8008  type (
  8009  	namedBool  bool
  8010  	namedBytes []byte
  8011  )
  8012  
  8013  func TestValue_Cap(t *testing.T) {
  8014  	a := &[3]int{1, 2, 3}
  8015  	v := ValueOf(a)
  8016  	if v.Cap() != cap(a) {
  8017  		t.Errorf("Cap = %d want %d", v.Cap(), cap(a))
  8018  	}
  8019  
  8020  	a = nil
  8021  	v = ValueOf(a)
  8022  	if v.Cap() != cap(a) {
  8023  		t.Errorf("Cap = %d want %d", v.Cap(), cap(a))
  8024  	}
  8025  
  8026  	getError := func(f func()) (errorStr string) {
  8027  		defer func() {
  8028  			e := recover()
  8029  			if str, ok := e.(string); ok {
  8030  				errorStr = str
  8031  			}
  8032  		}()
  8033  		f()
  8034  		return
  8035  	}
  8036  	e := getError(func() {
  8037  		var ptr *int
  8038  		ValueOf(ptr).Cap()
  8039  	})
  8040  	wantStr := "reflect: call of reflect.Value.Cap on ptr to non-array Value"
  8041  	if e != wantStr {
  8042  		t.Errorf("error is %q, want %q", e, wantStr)
  8043  	}
  8044  }
  8045  
  8046  func TestValue_Len(t *testing.T) {
  8047  	a := &[3]int{1, 2, 3}
  8048  	v := ValueOf(a)
  8049  	if v.Len() != len(a) {
  8050  		t.Errorf("Len = %d want %d", v.Len(), len(a))
  8051  	}
  8052  
  8053  	a = nil
  8054  	v = ValueOf(a)
  8055  	if v.Len() != len(a) {
  8056  		t.Errorf("Len = %d want %d", v.Len(), len(a))
  8057  	}
  8058  
  8059  	getError := func(f func()) (errorStr string) {
  8060  		defer func() {
  8061  			e := recover()
  8062  			if str, ok := e.(string); ok {
  8063  				errorStr = str
  8064  			}
  8065  		}()
  8066  		f()
  8067  		return
  8068  	}
  8069  	e := getError(func() {
  8070  		var ptr *int
  8071  		ValueOf(ptr).Len()
  8072  	})
  8073  	wantStr := "reflect: call of reflect.Value.Len on ptr to non-array Value"
  8074  	if e != wantStr {
  8075  		t.Errorf("error is %q, want %q", e, wantStr)
  8076  	}
  8077  }
  8078  
  8079  func TestValue_Comparable(t *testing.T) {
  8080  	var a int
  8081  	var s []int
  8082  	var i interface{} = a
  8083  	var iNil interface{}
  8084  	var iSlice interface{} = s
  8085  	var iArrayFalse interface{} = [2]interface{}{1, map[int]int{}}
  8086  	var iArrayTrue interface{} = [2]interface{}{1, struct{ I interface{} }{1}}
  8087  	var testcases = []struct {
  8088  		value      Value
  8089  		comparable bool
  8090  		deref      bool
  8091  	}{
  8092  		{
  8093  			ValueOf(&iNil),
  8094  			true,
  8095  			true,
  8096  		},
  8097  		{
  8098  			ValueOf(32),
  8099  			true,
  8100  			false,
  8101  		},
  8102  		{
  8103  			ValueOf(int8(1)),
  8104  			true,
  8105  			false,
  8106  		},
  8107  		{
  8108  			ValueOf(int16(1)),
  8109  			true,
  8110  			false,
  8111  		},
  8112  		{
  8113  			ValueOf(int32(1)),
  8114  			true,
  8115  			false,
  8116  		},
  8117  		{
  8118  			ValueOf(int64(1)),
  8119  			true,
  8120  			false,
  8121  		},
  8122  		{
  8123  			ValueOf(uint8(1)),
  8124  			true,
  8125  			false,
  8126  		},
  8127  		{
  8128  			ValueOf(uint16(1)),
  8129  			true,
  8130  			false,
  8131  		},
  8132  		{
  8133  			ValueOf(uint32(1)),
  8134  			true,
  8135  			false,
  8136  		},
  8137  		{
  8138  			ValueOf(uint64(1)),
  8139  			true,
  8140  			false,
  8141  		},
  8142  		{
  8143  			ValueOf(float32(1)),
  8144  			true,
  8145  			false,
  8146  		},
  8147  		{
  8148  			ValueOf(float64(1)),
  8149  			true,
  8150  			false,
  8151  		},
  8152  		{
  8153  			ValueOf(complex(float32(1), float32(1))),
  8154  			true,
  8155  			false,
  8156  		},
  8157  		{
  8158  			ValueOf(complex(float64(1), float64(1))),
  8159  			true,
  8160  			false,
  8161  		},
  8162  		{
  8163  			ValueOf("abc"),
  8164  			true,
  8165  			false,
  8166  		},
  8167  		{
  8168  			ValueOf(true),
  8169  			true,
  8170  			false,
  8171  		},
  8172  		{
  8173  			ValueOf(map[int]int{}),
  8174  			false,
  8175  			false,
  8176  		},
  8177  		{
  8178  			ValueOf([]int{}),
  8179  			false,
  8180  			false,
  8181  		},
  8182  		{
  8183  			Value{},
  8184  			false,
  8185  			false,
  8186  		},
  8187  		{
  8188  			ValueOf(&a),
  8189  			true,
  8190  			false,
  8191  		},
  8192  		{
  8193  			ValueOf(&s),
  8194  			true,
  8195  			false,
  8196  		},
  8197  		{
  8198  			ValueOf(&i),
  8199  			true,
  8200  			true,
  8201  		},
  8202  		{
  8203  			ValueOf(&iSlice),
  8204  			false,
  8205  			true,
  8206  		},
  8207  		{
  8208  			ValueOf([2]int{}),
  8209  			true,
  8210  			false,
  8211  		},
  8212  		{
  8213  			ValueOf([2]map[int]int{}),
  8214  			false,
  8215  			false,
  8216  		},
  8217  		{
  8218  			ValueOf([0]func(){}),
  8219  			false,
  8220  			false,
  8221  		},
  8222  		{
  8223  			ValueOf([2]struct{ I interface{} }{{1}, {1}}),
  8224  			true,
  8225  			false,
  8226  		},
  8227  		{
  8228  			ValueOf([2]struct{ I interface{} }{{[]int{}}, {1}}),
  8229  			false,
  8230  			false,
  8231  		},
  8232  		{
  8233  			ValueOf([2]interface{}{1, struct{ I int }{1}}),
  8234  			true,
  8235  			false,
  8236  		},
  8237  		{
  8238  			ValueOf([2]interface{}{[1]interface{}{map[int]int{}}, struct{ I int }{1}}),
  8239  			false,
  8240  			false,
  8241  		},
  8242  		{
  8243  			ValueOf(&iArrayFalse),
  8244  			false,
  8245  			true,
  8246  		},
  8247  		{
  8248  			ValueOf(&iArrayTrue),
  8249  			true,
  8250  			true,
  8251  		},
  8252  	}
  8253  
  8254  	for _, cas := range testcases {
  8255  		v := cas.value
  8256  		if cas.deref {
  8257  			v = v.Elem()
  8258  		}
  8259  		got := v.Comparable()
  8260  		if got != cas.comparable {
  8261  			t.Errorf("%T.Comparable = %t, want %t", v, got, cas.comparable)
  8262  		}
  8263  	}
  8264  }
  8265  
  8266  type ValueEqualTest struct {
  8267  	v, u           any
  8268  	eq             bool
  8269  	vDeref, uDeref bool
  8270  }
  8271  
  8272  var equalI interface{} = 1
  8273  var equalSlice interface{} = []int{1}
  8274  var nilInterface interface{}
  8275  var mapInterface interface{} = map[int]int{}
  8276  
  8277  var valueEqualTests = []ValueEqualTest{
  8278  	{
  8279  		Value{}, Value{},
  8280  		true,
  8281  		false, false,
  8282  	},
  8283  	{
  8284  		true, true,
  8285  		true,
  8286  		false, false,
  8287  	},
  8288  	{
  8289  		1, 1,
  8290  		true,
  8291  		false, false,
  8292  	},
  8293  	{
  8294  		int8(1), int8(1),
  8295  		true,
  8296  		false, false,
  8297  	},
  8298  	{
  8299  		int16(1), int16(1),
  8300  		true,
  8301  		false, false,
  8302  	},
  8303  	{
  8304  		int32(1), int32(1),
  8305  		true,
  8306  		false, false,
  8307  	},
  8308  	{
  8309  		int64(1), int64(1),
  8310  		true,
  8311  		false, false,
  8312  	},
  8313  	{
  8314  		uint(1), uint(1),
  8315  		true,
  8316  		false, false,
  8317  	},
  8318  	{
  8319  		uint8(1), uint8(1),
  8320  		true,
  8321  		false, false,
  8322  	},
  8323  	{
  8324  		uint16(1), uint16(1),
  8325  		true,
  8326  		false, false,
  8327  	},
  8328  	{
  8329  		uint32(1), uint32(1),
  8330  		true,
  8331  		false, false,
  8332  	},
  8333  	{
  8334  		uint64(1), uint64(1),
  8335  		true,
  8336  		false, false,
  8337  	},
  8338  	{
  8339  		float32(1), float32(1),
  8340  		true,
  8341  		false, false,
  8342  	},
  8343  	{
  8344  		float64(1), float64(1),
  8345  		true,
  8346  		false, false,
  8347  	},
  8348  	{
  8349  		complex(1, 1), complex(1, 1),
  8350  		true,
  8351  		false, false,
  8352  	},
  8353  	{
  8354  		complex128(1 + 1i), complex128(1 + 1i),
  8355  		true,
  8356  		false, false,
  8357  	},
  8358  	{
  8359  		func() {}, nil,
  8360  		false,
  8361  		false, false,
  8362  	},
  8363  	{
  8364  		&equalI, 1,
  8365  		true,
  8366  		true, false,
  8367  	},
  8368  	{
  8369  		(chan int)(nil), nil,
  8370  		false,
  8371  		false, false,
  8372  	},
  8373  	{
  8374  		(chan int)(nil), (chan int)(nil),
  8375  		true,
  8376  		false, false,
  8377  	},
  8378  	{
  8379  		&equalI, &equalI,
  8380  		true,
  8381  		false, false,
  8382  	},
  8383  	{
  8384  		struct{ i int }{1}, struct{ i int }{1},
  8385  		true,
  8386  		false, false,
  8387  	},
  8388  	{
  8389  		struct{ i int }{1}, struct{ i int }{2},
  8390  		false,
  8391  		false, false,
  8392  	},
  8393  	{
  8394  		&nilInterface, &nilInterface,
  8395  		true,
  8396  		true, true,
  8397  	},
  8398  	{
  8399  		1, ValueOf(struct{ i int }{1}).Field(0),
  8400  		true,
  8401  		false, false,
  8402  	},
  8403  }
  8404  
  8405  func TestValue_Equal(t *testing.T) {
  8406  	for _, test := range valueEqualTests {
  8407  		var v, u Value
  8408  		if vv, ok := test.v.(Value); ok {
  8409  			v = vv
  8410  		} else {
  8411  			v = ValueOf(test.v)
  8412  		}
  8413  
  8414  		if uu, ok := test.u.(Value); ok {
  8415  			u = uu
  8416  		} else {
  8417  			u = ValueOf(test.u)
  8418  		}
  8419  		if test.vDeref {
  8420  			v = v.Elem()
  8421  		}
  8422  
  8423  		if test.uDeref {
  8424  			u = u.Elem()
  8425  		}
  8426  
  8427  		if r := v.Equal(u); r != test.eq {
  8428  			t.Errorf("%s == %s got %t, want %t", v.Type(), u.Type(), r, test.eq)
  8429  		}
  8430  	}
  8431  }
  8432  
  8433  func TestValue_EqualNonComparable(t *testing.T) {
  8434  	var invalid = Value{} // ValueOf(nil)
  8435  	var values = []Value{
  8436  		// Value of slice is non-comparable.
  8437  		ValueOf([]int(nil)),
  8438  		ValueOf(([]int{})),
  8439  
  8440  		// Value of map is non-comparable.
  8441  		ValueOf(map[int]int(nil)),
  8442  		ValueOf((map[int]int{})),
  8443  
  8444  		// Value of func is non-comparable.
  8445  		ValueOf(((func())(nil))),
  8446  		ValueOf(func() {}),
  8447  
  8448  		// Value of struct is non-comparable because of non-comparable elements.
  8449  		ValueOf((NonComparableStruct{})),
  8450  
  8451  		// Value of array is non-comparable because of non-comparable elements.
  8452  		ValueOf([0]map[int]int{}),
  8453  		ValueOf([0]func(){}),
  8454  		ValueOf(([1]struct{ I interface{} }{{[]int{}}})),
  8455  		ValueOf(([1]interface{}{[1]interface{}{map[int]int{}}})),
  8456  	}
  8457  	for _, value := range values {
  8458  		// Panic when reflect.Value.Equal using two valid non-comparable values.
  8459  		shouldPanic("are not comparable", func() { value.Equal(value) })
  8460  
  8461  		// If one is non-comparable and the other is invalid, the expected result is always false.
  8462  		if r := value.Equal(invalid); r != false {
  8463  			t.Errorf("%s == invalid got %t, want false", value.Type(), r)
  8464  		}
  8465  	}
  8466  }
  8467  
  8468  func TestInitFuncTypes(t *testing.T) {
  8469  	n := 100
  8470  	var wg sync.WaitGroup
  8471  
  8472  	wg.Add(n)
  8473  	for i := 0; i < n; i++ {
  8474  		go func() {
  8475  			defer wg.Done()
  8476  			ipT := TypeOf(net.IP{})
  8477  			for i := 0; i < ipT.NumMethod(); i++ {
  8478  				_ = ipT.Method(i)
  8479  			}
  8480  		}()
  8481  	}
  8482  	wg.Wait()
  8483  }
  8484  
  8485  func TestClear(t *testing.T) {
  8486  	m := make(map[string]any, len(valueTests))
  8487  	for _, tt := range valueTests {
  8488  		m[tt.s] = tt.i
  8489  	}
  8490  	mapTestFn := func(v Value) bool { v.Clear(); return v.Len() == 0 }
  8491  
  8492  	s := make([]*pair, len(valueTests))
  8493  	for i := range s {
  8494  		s[i] = &valueTests[i]
  8495  	}
  8496  	sliceTestFn := func(v Value) bool {
  8497  		v.Clear()
  8498  		for i := 0; i < v.Len(); i++ {
  8499  			if !v.Index(i).IsZero() {
  8500  				return false
  8501  			}
  8502  		}
  8503  		return true
  8504  	}
  8505  
  8506  	panicTestFn := func(v Value) bool { shouldPanic("reflect.Value.Clear", func() { v.Clear() }); return true }
  8507  
  8508  	tests := []struct {
  8509  		name     string
  8510  		value    Value
  8511  		testFunc func(v Value) bool
  8512  	}{
  8513  		{"map", ValueOf(m), mapTestFn},
  8514  		{"slice no pointer", ValueOf([]int{1, 2, 3, 4, 5}), sliceTestFn},
  8515  		{"slice has pointer", ValueOf(s), sliceTestFn},
  8516  		{"non-map/slice", ValueOf(1), panicTestFn},
  8517  	}
  8518  
  8519  	for _, tc := range tests {
  8520  		tc := tc
  8521  		t.Run(tc.name, func(t *testing.T) {
  8522  			t.Parallel()
  8523  			if !tc.testFunc(tc.value) {
  8524  				t.Errorf("unexpected result for value.Clear(): %v", tc.value)
  8525  			}
  8526  		})
  8527  	}
  8528  }
  8529  
  8530  func TestValuePointerAndUnsafePointer(t *testing.T) {
  8531  	ptr := new(int)
  8532  	ch := make(chan int)
  8533  	m := make(map[int]int)
  8534  	unsafePtr := unsafe.Pointer(ptr)
  8535  	slice := make([]int, 1)
  8536  	fn := func() {}
  8537  	s := "foo"
  8538  
  8539  	tests := []struct {
  8540  		name              string
  8541  		val               Value
  8542  		wantUnsafePointer unsafe.Pointer
  8543  	}{
  8544  		{"pointer", ValueOf(ptr), unsafe.Pointer(ptr)},
  8545  		{"channel", ValueOf(ch), *(*unsafe.Pointer)(unsafe.Pointer(&ch))},
  8546  		{"map", ValueOf(m), *(*unsafe.Pointer)(unsafe.Pointer(&m))},
  8547  		{"unsafe.Pointer", ValueOf(unsafePtr), unsafePtr},
  8548  		{"function", ValueOf(fn), **(**unsafe.Pointer)(unsafe.Pointer(&fn))},
  8549  		{"slice", ValueOf(slice), unsafe.Pointer(unsafe.SliceData(slice))},
  8550  		{"string", ValueOf(s), unsafe.Pointer(unsafe.StringData(s))},
  8551  	}
  8552  
  8553  	for _, tc := range tests {
  8554  		tc := tc
  8555  		t.Run(tc.name, func(t *testing.T) {
  8556  			if got := tc.val.Pointer(); got != uintptr(tc.wantUnsafePointer) {
  8557  				t.Errorf("unexpected uintptr result, got %#x, want %#x", got, uintptr(tc.wantUnsafePointer))
  8558  			}
  8559  			if got := tc.val.UnsafePointer(); got != tc.wantUnsafePointer {
  8560  				t.Errorf("unexpected unsafe.Pointer result, got %#x, want %#x", got, tc.wantUnsafePointer)
  8561  			}
  8562  		})
  8563  	}
  8564  }
  8565  
  8566  // Test cases copied from ../../test/unsafebuiltins.go
  8567  func TestSliceAt(t *testing.T) {
  8568  	const maxUintptr = 1 << (8 * unsafe.Sizeof(uintptr(0)))
  8569  	var p [10]byte
  8570  
  8571  	typ := TypeOf(p[0])
  8572  
  8573  	s := SliceAt(typ, unsafe.Pointer(&p[0]), len(p))
  8574  	if s.Pointer() != uintptr(unsafe.Pointer(&p[0])) {
  8575  		t.Fatalf("unexpected underlying array: %d, want: %d", s.Pointer(), uintptr(unsafe.Pointer(&p[0])))
  8576  	}
  8577  	if s.Len() != len(p) || s.Cap() != len(p) {
  8578  		t.Fatalf("unexpected len or cap, len: %d, cap: %d, want: %d", s.Len(), s.Cap(), len(p))
  8579  	}
  8580  
  8581  	typ = TypeOf(0)
  8582  	if !SliceAt(typ, unsafe.Pointer((*int)(nil)), 0).IsNil() {
  8583  		t.Fatal("nil pointer with zero length must return nil")
  8584  	}
  8585  
  8586  	// nil pointer with positive length panics
  8587  	shouldPanic("", func() { _ = SliceAt(typ, unsafe.Pointer((*int)(nil)), 1) })
  8588  
  8589  	// negative length
  8590  	var neg int = -1
  8591  	shouldPanic("", func() { _ = SliceAt(TypeOf(byte(0)), unsafe.Pointer(&p[0]), neg) })
  8592  
  8593  	// size overflows address space
  8594  	n := uint64(0)
  8595  	shouldPanic("", func() { _ = SliceAt(TypeOf(n), unsafe.Pointer(&n), maxUintptr/8) })
  8596  	shouldPanic("", func() { _ = SliceAt(TypeOf(n), unsafe.Pointer(&n), maxUintptr/8+1) })
  8597  
  8598  	// sliced memory overflows address space
  8599  	last := (*byte)(unsafe.Pointer(^uintptr(0)))
  8600  	// This panics here, but won't panic in ../../test/unsafebuiltins.go,
  8601  	// because unsafe.Slice(last, 1) does not escape.
  8602  	//
  8603  	// _ = SliceAt(typ, unsafe.Pointer(last), 1)
  8604  	shouldPanic("", func() { _ = SliceAt(typ, unsafe.Pointer(last), 2) })
  8605  }
  8606  

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