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