stdlib_test.go

     1  // Copyright 2013 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  // This file tests types.Check by using it to
     6  // typecheck the standard library and tests.
     7  
     8  package types_test
     9  
    10  import (
    11  	"errors"
    12  	"fmt"
    13  	"go/ast"
    14  	"go/build"
    15  	"go/importer"
    16  	"go/parser"
    17  	"go/scanner"
    18  	"go/token"
    19  	"internal/testenv"
    20  	"os"
    21  	"path/filepath"
    22  	"runtime"
    23  	"slices"
    24  	"strings"
    25  	"sync"
    26  	"testing"
    27  	"time"
    28  
    29  	. "go/types"
    30  )
    31  
    32  // The cmd/*/internal packages may have been deleted as part of a binary
    33  // release. Import from source instead.
    34  //
    35  // (See https://golang.org/issue/43232 and
    36  // https://github.com/golang/build/blob/df58bbac082bc87c4a3cdfe336d1ffe60bbaa916/cmd/release/release.go#L533-L545.)
    37  //
    38  // Use the same importer for all std lib tests to
    39  // avoid repeated importing of the same packages.
    40  var stdLibImporter = importer.ForCompiler(token.NewFileSet(), "source", nil)
    41  
    42  func TestStdlib(t *testing.T) {
    43  	if testing.Short() {
    44  		t.Skip("skipping in short mode")
    45  	}
    46  
    47  	testenv.MustHaveGoBuild(t)
    48  
    49  	// Collect non-test files.
    50  	dirFiles := make(map[string][]string)
    51  	root := filepath.Join(testenv.GOROOT(t), "src")
    52  	walkPkgDirs(root, func(dir string, filenames []string) {
    53  		dirFiles[dir] = filenames
    54  	}, t.Error)
    55  
    56  	c := &stdlibChecker{
    57  		dirFiles: dirFiles,
    58  		pkgs:     make(map[string]*futurePackage),
    59  	}
    60  
    61  	start := time.Now()
    62  
    63  	// Though we read files while parsing, type-checking is otherwise CPU bound.
    64  	//
    65  	// This doesn't achieve great CPU utilization as many packages may block
    66  	// waiting for a common import, but in combination with the non-deterministic
    67  	// map iteration below this should provide decent coverage of concurrent
    68  	// type-checking (see golang/go#47729).
    69  	cpulimit := make(chan struct{}, runtime.GOMAXPROCS(0))
    70  	var wg sync.WaitGroup
    71  
    72  	for dir := range dirFiles {
    73  		cpulimit <- struct{}{}
    74  		wg.Add(1)
    75  		go func() {
    76  			defer func() {
    77  				wg.Done()
    78  				<-cpulimit
    79  			}()
    80  
    81  			_, err := c.getDirPackage(dir)
    82  			if err != nil {
    83  				t.Errorf("error checking %s: %v", dir, err)
    84  			}
    85  		}()
    86  	}
    87  
    88  	wg.Wait()
    89  
    90  	if testing.Verbose() {
    91  		fmt.Println(len(dirFiles), "packages typechecked in", time.Since(start))
    92  	}
    93  }
    94  
    95  // stdlibChecker implements concurrent type-checking of the packages defined by
    96  // dirFiles, which must define a closed set of packages (such as GOROOT/src).
    97  type stdlibChecker struct {
    98  	dirFiles map[string][]string // non-test files per directory; must be pre-populated
    99  
   100  	mu   sync.Mutex
   101  	pkgs map[string]*futurePackage // future cache of type-checking results
   102  }
   103  
   104  // A futurePackage is a future result of type-checking.
   105  type futurePackage struct {
   106  	done chan struct{} // guards pkg and err
   107  	pkg  *Package
   108  	err  error
   109  }
   110  
   111  func (c *stdlibChecker) Import(path string) (*Package, error) {
   112  	panic("unimplemented: use ImportFrom")
   113  }
   114  
   115  func (c *stdlibChecker) ImportFrom(path, dir string, _ ImportMode) (*Package, error) {
   116  	if path == "unsafe" {
   117  		// unsafe cannot be type checked normally.
   118  		return Unsafe, nil
   119  	}
   120  
   121  	p, err := build.Default.Import(path, dir, build.FindOnly)
   122  	if err != nil {
   123  		return nil, err
   124  	}
   125  
   126  	pkg, err := c.getDirPackage(p.Dir)
   127  	if pkg != nil {
   128  		// As long as pkg is non-nil, avoid redundant errors related to failed
   129  		// imports. TestStdlib will collect errors once for each package.
   130  		return pkg, nil
   131  	}
   132  	return nil, err
   133  }
   134  
   135  // getDirPackage gets the package defined in dir from the future cache.
   136  //
   137  // If this is the first goroutine requesting the package, getDirPackage
   138  // type-checks.
   139  func (c *stdlibChecker) getDirPackage(dir string) (*Package, error) {
   140  	c.mu.Lock()
   141  	fut, ok := c.pkgs[dir]
   142  	if !ok {
   143  		// First request for this package dir; type check.
   144  		fut = &futurePackage{
   145  			done: make(chan struct{}),
   146  		}
   147  		c.pkgs[dir] = fut
   148  		files, ok := c.dirFiles[dir]
   149  		c.mu.Unlock()
   150  		if !ok {
   151  			fut.err = fmt.Errorf("no files for %s", dir)
   152  		} else {
   153  			// Using dir as the package path here may be inconsistent with the behavior
   154  			// of a normal importer, but is sufficient as dir is by construction unique
   155  			// to this package.
   156  			fut.pkg, fut.err = typecheckFiles(dir, files, c)
   157  		}
   158  		close(fut.done)
   159  	} else {
   160  		// Otherwise, await the result.
   161  		c.mu.Unlock()
   162  		<-fut.done
   163  	}
   164  	return fut.pkg, fut.err
   165  }
   166  
   167  // firstComment returns the contents of the first non-empty comment in
   168  // the given file, "skip", or the empty string. No matter the present
   169  // comments, if any of them contains a build tag, the result is always
   170  // "skip". Only comments before the "package" token and within the first
   171  // 4K of the file are considered.
   172  func firstComment(filename string) string {
   173  	f, err := os.Open(filename)
   174  	if err != nil {
   175  		return ""
   176  	}
   177  	defer f.Close()
   178  
   179  	var src [4 << 10]byte // read at most 4KB
   180  	n, _ := f.Read(src[:])
   181  
   182  	var first string
   183  	var s scanner.Scanner
   184  	s.Init(fset.AddFile("", fset.Base(), n), src[:n], nil /* ignore errors */, scanner.ScanComments)
   185  	for {
   186  		_, tok, lit := s.Scan()
   187  		switch tok {
   188  		case token.COMMENT:
   189  			// remove trailing */ of multi-line comment
   190  			if lit[1] == '*' {
   191  				lit = lit[:len(lit)-2]
   192  			}
   193  			contents := strings.TrimSpace(lit[2:])
   194  			if strings.HasPrefix(contents, "go:build ") {
   195  				return "skip"
   196  			}
   197  			if first == "" {
   198  				first = contents // contents may be "" but that's ok
   199  			}
   200  			// continue as we may still see build tags
   201  
   202  		case token.PACKAGE, token.EOF:
   203  			return first
   204  		}
   205  	}
   206  }
   207  
   208  func testTestDir(t *testing.T, path string, ignore ...string) {
   209  	files, err := os.ReadDir(path)
   210  	if err != nil {
   211  		// cmd/distpack deletes GOROOT/test, so skip the test if it isn't present.
   212  		// cmd/distpack also requires GOROOT/VERSION to exist, so use that to
   213  		// suppress false-positive skips.
   214  		if _, err := os.Stat(filepath.Join(testenv.GOROOT(t), "test")); os.IsNotExist(err) {
   215  			if _, err := os.Stat(filepath.Join(testenv.GOROOT(t), "VERSION")); err == nil {
   216  				t.Skipf("skipping: GOROOT/test not present")
   217  			}
   218  		}
   219  		t.Fatal(err)
   220  	}
   221  
   222  	excluded := make(map[string]bool)
   223  	for _, filename := range ignore {
   224  		excluded[filename] = true
   225  	}
   226  
   227  	fset := token.NewFileSet()
   228  	for _, f := range files {
   229  		// filter directory contents
   230  		if f.IsDir() || !strings.HasSuffix(f.Name(), ".go") || excluded[f.Name()] {
   231  			continue
   232  		}
   233  
   234  		// get per-file instructions
   235  		expectErrors := false
   236  		filename := filepath.Join(path, f.Name())
   237  		goVersion := ""
   238  		if comment := firstComment(filename); comment != "" {
   239  			if strings.Contains(comment, "-goexperiment") {
   240  				continue // ignore this file
   241  			}
   242  			fields := strings.Fields(comment)
   243  			switch fields[0] {
   244  			case "skip", "compiledir":
   245  				continue // ignore this file
   246  			case "errorcheck":
   247  				expectErrors = true
   248  				for _, arg := range fields[1:] {
   249  					if arg == "-0" || arg == "-+" || arg == "-std" {
   250  						// Marked explicitly as not expecting errors (-0),
   251  						// or marked as compiling runtime/stdlib, which is only done
   252  						// to trigger runtime/stdlib-only error output.
   253  						// In both cases, the code should typecheck.
   254  						expectErrors = false
   255  						break
   256  					}
   257  					const prefix = "-lang="
   258  					if strings.HasPrefix(arg, prefix) {
   259  						goVersion = arg[len(prefix):]
   260  					}
   261  				}
   262  			}
   263  		}
   264  
   265  		// parse and type-check file
   266  		file, err := parser.ParseFile(fset, filename, nil, 0)
   267  		if err == nil {
   268  			conf := Config{
   269  				GoVersion: goVersion,
   270  				Importer:  stdLibImporter,
   271  			}
   272  			_, err = conf.Check(filename, fset, []*ast.File{file}, nil)
   273  		}
   274  
   275  		if expectErrors {
   276  			if err == nil {
   277  				t.Errorf("expected errors but found none in %s", filename)
   278  			}
   279  		} else {
   280  			if err != nil {
   281  				t.Error(err)
   282  			}
   283  		}
   284  	}
   285  }
   286  
   287  func TestStdTest(t *testing.T) {
   288  	testenv.MustHaveGoBuild(t)
   289  
   290  	if testing.Short() && testenv.Builder() == "" {
   291  		t.Skip("skipping in short mode")
   292  	}
   293  
   294  	testTestDir(t, filepath.Join(testenv.GOROOT(t), "test"),
   295  		"cmplxdivide.go", // also needs file cmplxdivide1.go - ignore
   296  		"directive.go",   // tests compiler rejection of bad directive placement - ignore
   297  		"directive2.go",  // tests compiler rejection of bad directive placement - ignore
   298  		"embedfunc.go",   // tests //go:embed
   299  		"embedvers.go",   // tests //go:embed
   300  		"linkname2.go",   // go/types doesn't check validity of //go:xxx directives
   301  		"linkname3.go",   // go/types doesn't check validity of //go:xxx directives
   302  	)
   303  }
   304  
   305  func TestStdFixed(t *testing.T) {
   306  	testenv.MustHaveGoBuild(t)
   307  
   308  	if testing.Short() && testenv.Builder() == "" {
   309  		t.Skip("skipping in short mode")
   310  	}
   311  
   312  	testTestDir(t, filepath.Join(testenv.GOROOT(t), "test", "fixedbugs"),
   313  		"bug248.go", "bug302.go", "bug369.go", // complex test instructions - ignore
   314  		"bug398.go",      // go/types doesn't check for anonymous interface cycles (go.dev/issue/56103)
   315  		"issue6889.go",   // gc-specific test
   316  		"issue11362.go",  // canonical import path check
   317  		"issue16369.go",  // go/types handles this correctly - not an issue
   318  		"issue18459.go",  // go/types doesn't check validity of //go:xxx directives
   319  		"issue18882.go",  // go/types doesn't check validity of //go:xxx directives
   320  		"issue20027.go",  // go/types does not have constraints on channel element size
   321  		"issue20529.go",  // go/types does not have constraints on stack size
   322  		"issue22200.go",  // go/types does not have constraints on stack size
   323  		"issue22200b.go", // go/types does not have constraints on stack size
   324  		"issue25507.go",  // go/types does not have constraints on stack size
   325  		"issue20780.go",  // go/types does not have constraints on stack size
   326  		"bug251.go",      // go.dev/issue/34333 which was exposed with fix for go.dev/issue/34151
   327  		"issue42058a.go", // go/types does not have constraints on channel element size
   328  		"issue42058b.go", // go/types does not have constraints on channel element size
   329  		"issue48097.go",  // go/types doesn't check validity of //go:xxx directives, and non-init bodyless function
   330  		"issue48230.go",  // go/types doesn't check validity of //go:xxx directives
   331  		"issue49767.go",  // go/types does not have constraints on channel element size
   332  		"issue49814.go",  // go/types does not have constraints on array size
   333  		"issue56103.go",  // anonymous interface cycles; will be a type checker error in 1.22
   334  		"issue52697.go",  // go/types does not have constraints on stack size
   335  		"issue68054.go",  // this test requires GODEBUG=gotypesalias=1
   336  		"issue68580.go",  // this test requires GODEBUG=gotypesalias=1
   337  		"issue73309.go",  // this test requires GODEBUG=gotypesalias=1
   338  		"issue73309b.go", // this test requires GODEBUG=gotypesalias=1
   339  
   340  		// These tests requires runtime/cgo.Incomplete, which is only available on some platforms.
   341  		// However, go/types does not know about build constraints.
   342  		"bug514.go",
   343  		"issue40954.go",
   344  		"issue42032.go",
   345  		"issue42076.go",
   346  		"issue46903.go",
   347  		"issue51733.go",
   348  		"notinheap2.go",
   349  		"notinheap3.go",
   350  	)
   351  }
   352  
   353  func TestStdKen(t *testing.T) {
   354  	testenv.MustHaveGoBuild(t)
   355  
   356  	testTestDir(t, filepath.Join(testenv.GOROOT(t), "test", "ken"))
   357  }
   358  
   359  // Package paths of excluded packages.
   360  var excluded = map[string]bool{
   361  	"builtin":                       true,
   362  	"cmd/compile/internal/ssa/_gen": true,
   363  	"runtime/_mkmalloc":             true,
   364  }
   365  
   366  // printPackageMu synchronizes the printing of type-checked package files in
   367  // the typecheckFiles function.
   368  //
   369  // Without synchronization, package files may be interleaved during concurrent
   370  // type-checking.
   371  var printPackageMu sync.Mutex
   372  
   373  // typecheckFiles typechecks the given package files.
   374  func typecheckFiles(path string, filenames []string, importer Importer) (*Package, error) {
   375  	fset := token.NewFileSet()
   376  
   377  	// Parse package files.
   378  	var files []*ast.File
   379  	for _, filename := range filenames {
   380  		file, err := parser.ParseFile(fset, filename, nil, parser.AllErrors)
   381  		if err != nil {
   382  			return nil, err
   383  		}
   384  
   385  		files = append(files, file)
   386  	}
   387  
   388  	if testing.Verbose() {
   389  		printPackageMu.Lock()
   390  		fmt.Println("package", files[0].Name.Name)
   391  		for _, filename := range filenames {
   392  			fmt.Println("\t", filename)
   393  		}
   394  		printPackageMu.Unlock()
   395  	}
   396  
   397  	// Typecheck package files.
   398  	var errs []error
   399  	conf := Config{
   400  		Error: func(err error) {
   401  			errs = append(errs, err)
   402  		},
   403  		Importer: importer,
   404  	}
   405  	info := Info{Uses: make(map[*ast.Ident]Object)}
   406  	pkg, _ := conf.Check(path, fset, files, &info)
   407  	err := errors.Join(errs...)
   408  	if err != nil {
   409  		return pkg, err
   410  	}
   411  
   412  	// Perform checks of API invariants.
   413  
   414  	// All Objects have a package, except predeclared ones.
   415  	errorError := Universe.Lookup("error").Type().Underlying().(*Interface).ExplicitMethod(0) // (error).Error
   416  	for id, obj := range info.Uses {
   417  		predeclared := obj == Universe.Lookup(obj.Name()) || obj == errorError
   418  		if predeclared == (obj.Pkg() != nil) {
   419  			posn := fset.Position(id.Pos())
   420  			if predeclared {
   421  				return nil, fmt.Errorf("%s: predeclared object with package: %s", posn, obj)
   422  			} else {
   423  				return nil, fmt.Errorf("%s: user-defined object without package: %s", posn, obj)
   424  			}
   425  		}
   426  	}
   427  
   428  	return pkg, nil
   429  }
   430  
   431  // pkgFilenames returns the list of package filenames for the given directory.
   432  func pkgFilenames(dir string, includeTest bool) ([]string, error) {
   433  	ctxt := build.Default
   434  	ctxt.CgoEnabled = false
   435  	pkg, err := ctxt.ImportDir(dir, 0)
   436  	if err != nil {
   437  		if _, nogo := err.(*build.NoGoError); nogo {
   438  			return nil, nil // no *.go files, not an error
   439  		}
   440  		return nil, err
   441  	}
   442  	if excluded[pkg.ImportPath] {
   443  		return nil, nil
   444  	}
   445  	if slices.Contains(strings.Split(pkg.ImportPath, "/"), "_asm") {
   446  		// Submodules where not all dependencies are available.
   447  		// See go.dev/issue/46027.
   448  		return nil, nil
   449  	}
   450  	var filenames []string
   451  	for _, name := range pkg.GoFiles {
   452  		filenames = append(filenames, filepath.Join(pkg.Dir, name))
   453  	}
   454  	if includeTest {
   455  		for _, name := range pkg.TestGoFiles {
   456  			filenames = append(filenames, filepath.Join(pkg.Dir, name))
   457  		}
   458  	}
   459  	return filenames, nil
   460  }
   461  
   462  func walkPkgDirs(dir string, pkgh func(dir string, filenames []string), errh func(args ...any)) {
   463  	w := walker{pkgh, errh}
   464  	w.walk(dir)
   465  }
   466  
   467  type walker struct {
   468  	pkgh func(dir string, filenames []string)
   469  	errh func(args ...any)
   470  }
   471  
   472  func (w *walker) walk(dir string) {
   473  	files, err := os.ReadDir(dir)
   474  	if err != nil {
   475  		w.errh(err)
   476  		return
   477  	}
   478  
   479  	// apply pkgh to the files in directory dir
   480  
   481  	// Don't get test files as these packages are imported.
   482  	pkgFiles, err := pkgFilenames(dir, false)
   483  	if err != nil {
   484  		w.errh(err)
   485  		return
   486  	}
   487  	if pkgFiles != nil {
   488  		w.pkgh(dir, pkgFiles)
   489  	}
   490  
   491  	// traverse subdirectories, but don't walk into testdata
   492  	for _, f := range files {
   493  		if f.IsDir() && f.Name() != "testdata" {
   494  			w.walk(filepath.Join(dir, f.Name()))
   495  		}
   496  	}
   497  }
   498
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