1 // Copyright 2011 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.
33 // A Context specifies the supporting context for a build.
35 GOARCH string // target architecture
36 GOOS string // target operating system
37 GOROOT string // Go root
38 GOPATH string // Go paths
40 // Dir is the caller's working directory, or the empty string to use
41 // the current directory of the running process. In module mode, this is used
42 // to locate the main module.
44 // If Dir is non-empty, directories passed to Import and ImportDir must
48 CgoEnabled bool // whether cgo files are included
49 UseAllFiles bool // use files regardless of go:build lines, file names
50 Compiler string // compiler to assume when computing target paths
52 // The build, tool, and release tags specify build constraints
53 // that should be considered satisfied when processing go:build lines.
54 // Clients creating a new context may customize BuildTags, which
55 // defaults to empty, but it is usually an error to customize ToolTags or ReleaseTags.
56 // ToolTags defaults to build tags appropriate to the current Go toolchain configuration.
57 // ReleaseTags defaults to the list of Go releases the current release is compatible with.
58 // BuildTags is not set for the Default build Context.
59 // In addition to the BuildTags, ToolTags, and ReleaseTags, build constraints
60 // consider the values of GOARCH and GOOS as satisfied tags.
61 // The last element in ReleaseTags is assumed to be the current release.
66 // The install suffix specifies a suffix to use in the name of the installation
67 // directory. By default it is empty, but custom builds that need to keep
68 // their outputs separate can set InstallSuffix to do so. For example, when
69 // using the race detector, the go command uses InstallSuffix = "race", so
70 // that on a Linux/386 system, packages are written to a directory named
71 // "linux_386_race" instead of the usual "linux_386".
74 // By default, Import uses the operating system's file system calls
75 // to read directories and files. To read from other sources,
76 // callers can set the following functions. They all have default
77 // behaviors that use the local file system, so clients need only set
78 // the functions whose behaviors they wish to change.
80 // JoinPath joins the sequence of path fragments into a single path.
81 // If JoinPath is nil, Import uses filepath.Join.
82 JoinPath func(elem ...string) string
84 // SplitPathList splits the path list into a slice of individual paths.
85 // If SplitPathList is nil, Import uses filepath.SplitList.
86 SplitPathList func(list string) []string
88 // IsAbsPath reports whether path is an absolute path.
89 // If IsAbsPath is nil, Import uses filepath.IsAbs.
90 IsAbsPath func(path string) bool
92 // IsDir reports whether the path names a directory.
93 // If IsDir is nil, Import calls os.Stat and uses the result's IsDir method.
94 IsDir func(path string) bool
96 // HasSubdir reports whether dir is lexically a subdirectory of
97 // root, perhaps multiple levels below. It does not try to check
98 // whether dir exists.
99 // If so, HasSubdir sets rel to a slash-separated path that
100 // can be joined to root to produce a path equivalent to dir.
101 // If HasSubdir is nil, Import uses an implementation built on
102 // filepath.EvalSymlinks.
103 HasSubdir func(root, dir string) (rel string, ok bool)
105 // ReadDir returns a slice of fs.FileInfo, sorted by Name,
106 // describing the content of the named directory.
107 // If ReadDir is nil, Import uses os.ReadDir.
108 ReadDir func(dir string) ([]fs.FileInfo, error)
110 // OpenFile opens a file (not a directory) for reading.
111 // If OpenFile is nil, Import uses os.Open.
112 OpenFile func(path string) (io.ReadCloser, error)
115 // joinPath calls ctxt.JoinPath (if not nil) or else filepath.Join.
116 func (ctxt *Context) joinPath(elem ...string) string {
117 if f := ctxt.JoinPath; f != nil {
120 return filepath.Join(elem...)
123 // splitPathList calls ctxt.SplitPathList (if not nil) or else filepath.SplitList.
124 func (ctxt *Context) splitPathList(s string) []string {
125 if f := ctxt.SplitPathList; f != nil {
128 return filepath.SplitList(s)
131 // isAbsPath calls ctxt.IsAbsPath (if not nil) or else filepath.IsAbs.
132 func (ctxt *Context) isAbsPath(path string) bool {
133 if f := ctxt.IsAbsPath; f != nil {
136 return filepath.IsAbs(path)
139 // isDir calls ctxt.IsDir (if not nil) or else uses os.Stat.
140 func (ctxt *Context) isDir(path string) bool {
141 if f := ctxt.IsDir; f != nil {
144 fi, err := os.Stat(path)
145 return err == nil && fi.IsDir()
148 // hasSubdir calls ctxt.HasSubdir (if not nil) or else uses
149 // the local file system to answer the question.
150 func (ctxt *Context) hasSubdir(root, dir string) (rel string, ok bool) {
151 if f := ctxt.HasSubdir; f != nil {
155 // Try using paths we received.
156 if rel, ok = hasSubdir(root, dir); ok {
160 // Try expanding symlinks and comparing
161 // expanded against unexpanded and
162 // expanded against expanded.
163 rootSym, _ := filepath.EvalSymlinks(root)
164 dirSym, _ := filepath.EvalSymlinks(dir)
166 if rel, ok = hasSubdir(rootSym, dir); ok {
169 if rel, ok = hasSubdir(root, dirSym); ok {
172 return hasSubdir(rootSym, dirSym)
175 // hasSubdir reports if dir is within root by performing lexical analysis only.
176 func hasSubdir(root, dir string) (rel string, ok bool) {
177 const sep = string(filepath.Separator)
178 root = filepath.Clean(root)
179 if !strings.HasSuffix(root, sep) {
182 dir = filepath.Clean(dir)
183 after, found := strings.CutPrefix(dir, root)
187 return filepath.ToSlash(after), true
190 // readDir calls ctxt.ReadDir (if not nil) or else os.ReadDir.
191 func (ctxt *Context) readDir(path string) ([]fs.DirEntry, error) {
192 // TODO: add a fs.DirEntry version of Context.ReadDir
193 if f := ctxt.ReadDir; f != nil {
198 des := make([]fs.DirEntry, len(fis))
199 for i, fi := range fis {
200 des[i] = fs.FileInfoToDirEntry(fi)
204 return os.ReadDir(path)
207 // openFile calls ctxt.OpenFile (if not nil) or else os.Open.
208 func (ctxt *Context) openFile(path string) (io.ReadCloser, error) {
209 if fn := ctxt.OpenFile; fn != nil {
213 f, err := os.Open(path)
215 return nil, err // nil interface
220 // isFile determines whether path is a file by trying to open it.
221 // It reuses openFile instead of adding another function to the
223 func (ctxt *Context) isFile(path string) bool {
224 f, err := ctxt.openFile(path)
232 // gopath returns the list of Go path directories.
233 func (ctxt *Context) gopath() []string {
235 for _, p := range ctxt.splitPathList(ctxt.GOPATH) {
236 if p == "" || p == ctxt.GOROOT {
237 // Empty paths are uninteresting.
238 // If the path is the GOROOT, ignore it.
239 // People sometimes set GOPATH=$GOROOT.
240 // Do not get confused by this common mistake.
243 if strings.HasPrefix(p, "~") {
244 // Path segments starting with ~ on Unix are almost always
245 // users who have incorrectly quoted ~ while setting GOPATH,
246 // preventing it from expanding to $HOME.
247 // The situation is made more confusing by the fact that
248 // bash allows quoted ~ in $PATH (most shells do not).
249 // Do not get confused by this, and do not try to use the path.
250 // It does not exist, and printing errors about it confuses
251 // those users even more, because they think "sure ~ exists!".
252 // The go command diagnoses this situation and prints a
254 // On Windows, ~ is used in short names, such as c:\progra~1
255 // for c:\program files.
263 // SrcDirs returns a list of package source root directories.
264 // It draws from the current Go root and Go path but omits directories
265 // that do not exist.
266 func (ctxt *Context) SrcDirs() []string {
268 if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
269 dir := ctxt.joinPath(ctxt.GOROOT, "src")
271 all = append(all, dir)
274 for _, p := range ctxt.gopath() {
275 dir := ctxt.joinPath(p, "src")
277 all = append(all, dir)
283 // Default is the default Context for builds.
284 // It uses the GOARCH, GOOS, GOROOT, and GOPATH environment variables
285 // if set, or else the compiled code's GOARCH, GOOS, and GOROOT.
286 var Default Context = defaultContext()
288 func defaultGOPATH() string {
290 if runtime.GOOS == "windows" {
292 } else if runtime.GOOS == "plan9" {
295 if home := os.Getenv(env); home != "" {
296 def := filepath.Join(home, "go")
297 if filepath.Clean(def) == filepath.Clean(runtime.GOROOT()) {
298 // Don't set the default GOPATH to GOROOT,
299 // as that will trigger warnings from the go tool.
307 var defaultToolTags, defaultReleaseTags []string
309 func defaultContext() Context {
312 c.GOARCH = buildcfg.GOARCH
313 c.GOOS = buildcfg.GOOS
314 if goroot := runtime.GOROOT(); goroot != "" {
315 c.GOROOT = filepath.Clean(goroot)
317 c.GOPATH = envOr("GOPATH", defaultGOPATH())
318 c.Compiler = runtime.Compiler
319 c.ToolTags = append(c.ToolTags, buildcfg.ToolTags...)
321 defaultToolTags = append([]string{}, c.ToolTags...) // our own private copy
323 // Each major Go release in the Go 1.x series adds a new
324 // "go1.x" release tag. That is, the go1.x tag is present in
325 // all releases >= Go 1.x. Code that requires Go 1.x or later
326 // should say "go:build go1.x", and code that should only be
327 // built before Go 1.x (perhaps it is the stub to use in that
328 // case) should say "go:build !go1.x".
329 // The last element in ReleaseTags is the current release.
330 for i := 1; i <= goversion.Version; i++ {
331 c.ReleaseTags = append(c.ReleaseTags, "go1."+strconv.Itoa(i))
334 defaultReleaseTags = append([]string{}, c.ReleaseTags...) // our own private copy
336 env := os.Getenv("CGO_ENABLED")
338 env = defaultCGO_ENABLED
346 // cgo must be explicitly enabled for cross compilation builds
347 if runtime.GOARCH == c.GOARCH && runtime.GOOS == c.GOOS {
348 c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
357 func envOr(name, def string) string {
365 // An ImportMode controls the behavior of the Import method.
369 // If FindOnly is set, Import stops after locating the directory
370 // that should contain the sources for a package. It does not
371 // read any files in the directory.
372 FindOnly ImportMode = 1 << iota
374 // If AllowBinary is set, Import can be satisfied by a compiled
375 // package object without corresponding sources.
378 // The supported way to create a compiled-only package is to
379 // write source code containing a //go:binary-only-package comment at
380 // the top of the file. Such a package will be recognized
381 // regardless of this flag setting (because it has source code)
382 // and will have BinaryOnly set to true in the returned Package.
385 // If ImportComment is set, parse import comments on package statements.
386 // Import returns an error if it finds a comment it cannot understand
387 // or finds conflicting comments in multiple source files.
388 // See golang.org/s/go14customimport for more information.
391 // By default, Import searches vendor directories
392 // that apply in the given source directory before searching
393 // the GOROOT and GOPATH roots.
394 // If an Import finds and returns a package using a vendor
395 // directory, the resulting ImportPath is the complete path
396 // to the package, including the path elements leading up
397 // to and including "vendor".
398 // For example, if Import("y", "x/subdir", 0) finds
399 // "x/vendor/y", the returned package's ImportPath is "x/vendor/y",
401 // See golang.org/s/go15vendor for more information.
403 // Setting IgnoreVendor ignores vendor directories.
405 // In contrast to the package's ImportPath,
406 // the returned package's Imports, TestImports, and XTestImports
407 // are always the exact import paths from the source files:
408 // Import makes no attempt to resolve or check those paths.
412 // A Package describes the Go package found in a directory.
413 type Package struct {
414 Dir string // directory containing package sources
415 Name string // package name
416 ImportComment string // path in import comment on package statement
417 Doc string // documentation synopsis
418 ImportPath string // import path of package ("" if unknown)
419 Root string // root of Go tree where this package lives
420 SrcRoot string // package source root directory ("" if unknown)
421 PkgRoot string // package install root directory ("" if unknown)
422 PkgTargetRoot string // architecture dependent install root directory ("" if unknown)
423 BinDir string // command install directory ("" if unknown)
424 Goroot bool // package found in Go root
425 PkgObj string // installed .a file
426 AllTags []string // tags that can influence file selection in this directory
427 ConflictDir string // this directory shadows Dir in $GOPATH
428 BinaryOnly bool // cannot be rebuilt from source (has //go:binary-only-package comment)
431 GoFiles []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
432 CgoFiles []string // .go source files that import "C"
433 IgnoredGoFiles []string // .go source files ignored for this build (including ignored _test.go files)
434 InvalidGoFiles []string // .go source files with detected problems (parse error, wrong package name, and so on)
435 IgnoredOtherFiles []string // non-.go source files ignored for this build
436 CFiles []string // .c source files
437 CXXFiles []string // .cc, .cpp and .cxx source files
438 MFiles []string // .m (Objective-C) source files
439 HFiles []string // .h, .hh, .hpp and .hxx source files
440 FFiles []string // .f, .F, .for and .f90 Fortran source files
441 SFiles []string // .s source files
442 SwigFiles []string // .swig files
443 SwigCXXFiles []string // .swigcxx files
444 SysoFiles []string // .syso system object files to add to archive
447 CgoCFLAGS []string // Cgo CFLAGS directives
448 CgoCPPFLAGS []string // Cgo CPPFLAGS directives
449 CgoCXXFLAGS []string // Cgo CXXFLAGS directives
450 CgoFFLAGS []string // Cgo FFLAGS directives
451 CgoLDFLAGS []string // Cgo LDFLAGS directives
452 CgoPkgConfig []string // Cgo pkg-config directives
455 TestGoFiles []string // _test.go files in package
456 XTestGoFiles []string // _test.go files outside package
458 // Go directive comments (//go:zzz...) found in source files.
459 Directives []Directive
460 TestDirectives []Directive
461 XTestDirectives []Directive
463 // Dependency information
464 Imports []string // import paths from GoFiles, CgoFiles
465 ImportPos map[string][]token.Position // line information for Imports
466 TestImports []string // import paths from TestGoFiles
467 TestImportPos map[string][]token.Position // line information for TestImports
468 XTestImports []string // import paths from XTestGoFiles
469 XTestImportPos map[string][]token.Position // line information for XTestImports
471 // //go:embed patterns found in Go source files
472 // For example, if a source file says
474 // then the list will contain those two strings as separate entries.
475 // (See package embed for more details about //go:embed.)
476 EmbedPatterns []string // patterns from GoFiles, CgoFiles
477 EmbedPatternPos map[string][]token.Position // line information for EmbedPatterns
478 TestEmbedPatterns []string // patterns from TestGoFiles
479 TestEmbedPatternPos map[string][]token.Position // line information for TestEmbedPatterns
480 XTestEmbedPatterns []string // patterns from XTestGoFiles
481 XTestEmbedPatternPos map[string][]token.Position // line information for XTestEmbedPatternPos
484 // A Directive is a Go directive comment (//go:zzz...) found in a source file.
485 type Directive struct {
486 Text string // full line comment including leading slashes
487 Pos token.Position // position of comment
490 // IsCommand reports whether the package is considered a
491 // command to be installed (not just a library).
492 // Packages named "main" are treated as commands.
493 func (p *Package) IsCommand() bool {
494 return p.Name == "main"
497 // ImportDir is like Import but processes the Go package found in
498 // the named directory.
499 func (ctxt *Context) ImportDir(dir string, mode ImportMode) (*Package, error) {
500 return ctxt.Import(".", dir, mode)
503 // NoGoError is the error used by Import to describe a directory
504 // containing no buildable Go source files. (It may still contain
505 // test files, files hidden by build tags, and so on.)
506 type NoGoError struct {
510 func (e *NoGoError) Error() string {
511 return "no buildable Go source files in " + e.Dir
514 // MultiplePackageError describes a directory containing
515 // multiple buildable Go source files for multiple packages.
516 type MultiplePackageError struct {
517 Dir string // directory containing files
518 Packages []string // package names found
519 Files []string // corresponding files: Files[i] declares package Packages[i]
522 func (e *MultiplePackageError) Error() string {
523 // Error string limited to two entries for compatibility.
524 return fmt.Sprintf("found packages %s (%s) and %s (%s) in %s", e.Packages[0], e.Files[0], e.Packages[1], e.Files[1], e.Dir)
527 func nameExt(name string) string {
528 i := strings.LastIndex(name, ".")
535 var installgoroot = godebug.New("installgoroot")
537 // Import returns details about the Go package named by the import path,
538 // interpreting local import paths relative to the srcDir directory.
539 // If the path is a local import path naming a package that can be imported
540 // using a standard import path, the returned package will set p.ImportPath
543 // In the directory containing the package, .go, .c, .h, and .s files are
544 // considered part of the package except for:
546 // - .go files in package documentation
547 // - files starting with _ or . (likely editor temporary files)
548 // - files with build constraints not satisfied by the context
550 // If an error occurs, Import returns a non-nil error and a non-nil
551 // *Package containing partial information.
552 func (ctxt *Context) Import(path string, srcDir string, mode ImportMode) (*Package, error) {
557 return p, fmt.Errorf("import %q: invalid import path", path)
560 var pkgtargetroot string
564 if ctxt.InstallSuffix != "" {
565 suffix = "_" + ctxt.InstallSuffix
567 switch ctxt.Compiler {
569 pkgtargetroot = "pkg/gccgo_" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
571 pkgtargetroot = "pkg/" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
573 // Save error for end of function.
574 pkgerr = fmt.Errorf("import %q: unknown compiler %q", path, ctxt.Compiler)
577 switch ctxt.Compiler {
579 dir, elem := pathpkg.Split(p.ImportPath)
580 pkga = pkgtargetroot + "/" + dir + "lib" + elem + ".a"
582 pkga = pkgtargetroot + "/" + p.ImportPath + ".a"
588 if IsLocalImport(path) {
589 pkga = "" // local imports have no installed path
591 return p, fmt.Errorf("import %q: import relative to unknown directory", path)
593 if !ctxt.isAbsPath(path) {
594 p.Dir = ctxt.joinPath(srcDir, path)
596 // p.Dir directory may or may not exist. Gather partial information first, check if it exists later.
597 // Determine canonical import path, if any.
598 // Exclude results where the import path would include /testdata/.
599 inTestdata := func(sub string) bool {
600 return strings.Contains(sub, "/testdata/") || strings.HasSuffix(sub, "/testdata") || strings.HasPrefix(sub, "testdata/") || sub == "testdata"
602 if ctxt.GOROOT != "" {
603 root := ctxt.joinPath(ctxt.GOROOT, "src")
604 if sub, ok := ctxt.hasSubdir(root, p.Dir); ok && !inTestdata(sub) {
608 setPkga() // p.ImportPath changed
613 for i, root := range all {
614 rootsrc := ctxt.joinPath(root, "src")
615 if sub, ok := ctxt.hasSubdir(rootsrc, p.Dir); ok && !inTestdata(sub) {
616 // We found a potential import path for dir,
617 // but check that using it wouldn't find something
619 if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
620 if dir := ctxt.joinPath(ctxt.GOROOT, "src", sub); ctxt.isDir(dir) {
625 for _, earlyRoot := range all[:i] {
626 if dir := ctxt.joinPath(earlyRoot, "src", sub); ctxt.isDir(dir) {
632 // sub would not name some other directory instead of this one.
636 setPkga() // p.ImportPath changed
640 // It's okay that we didn't find a root containing dir.
641 // Keep going with the information we have.
643 if strings.HasPrefix(path, "/") {
644 return p, fmt.Errorf("import %q: cannot import absolute path", path)
647 if err := ctxt.importGo(p, path, srcDir, mode); err == nil {
649 } else if err != errNoModules {
653 gopath := ctxt.gopath() // needed twice below; avoid computing many times
655 // tried records the location of unsuccessful package lookups
662 // Vendor directories get first chance to satisfy import.
663 if mode&IgnoreVendor == 0 && srcDir != "" {
664 searchVendor := func(root string, isGoroot bool) bool {
665 sub, ok := ctxt.hasSubdir(root, srcDir)
666 if !ok || !strings.HasPrefix(sub, "src/") || strings.Contains(sub, "/testdata/") {
670 vendor := ctxt.joinPath(root, sub, "vendor")
671 if ctxt.isDir(vendor) {
672 dir := ctxt.joinPath(vendor, path)
673 if ctxt.isDir(dir) && hasGoFiles(ctxt, dir) {
675 p.ImportPath = strings.TrimPrefix(pathpkg.Join(sub, "vendor", path), "src/")
678 setPkga() // p.ImportPath changed
681 tried.vendor = append(tried.vendor, dir)
683 i := strings.LastIndex(sub, "/")
691 if ctxt.Compiler != "gccgo" && ctxt.GOROOT != "" && searchVendor(ctxt.GOROOT, true) {
694 for _, root := range gopath {
695 if searchVendor(root, false) {
701 // Determine directory from import path.
702 if ctxt.GOROOT != "" {
703 // If the package path starts with "vendor/", only search GOROOT before
704 // GOPATH if the importer is also within GOROOT. That way, if the user has
705 // vendored in a package that is subsequently included in the standard
706 // distribution, they'll continue to pick up their own vendored copy.
707 gorootFirst := srcDir == "" || !strings.HasPrefix(path, "vendor/")
709 _, gorootFirst = ctxt.hasSubdir(ctxt.GOROOT, srcDir)
712 dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
713 if ctxt.Compiler != "gccgo" {
714 isDir := ctxt.isDir(dir)
715 binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
716 if isDir || binaryOnly {
725 if ctxt.Compiler == "gccgo" && goroot.IsStandardPackage(ctxt.GOROOT, ctxt.Compiler, path) {
726 // TODO(bcmills): Setting p.Dir here is misleading, because gccgo
727 // doesn't actually load its standard-library packages from this
728 // directory. See if we can leave it unset.
729 p.Dir = ctxt.joinPath(ctxt.GOROOT, "src", path)
735 for _, root := range gopath {
736 dir := ctxt.joinPath(root, "src", path)
737 isDir := ctxt.isDir(dir)
738 binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(root, pkga))
739 if isDir || binaryOnly {
744 tried.gopath = append(tried.gopath, dir)
747 // If we tried GOPATH first due to a "vendor/" prefix, fall back to GOPATH.
748 // That way, the user can still get useful results from 'go list' for
749 // standard-vendored paths passed on the command line.
750 if ctxt.GOROOT != "" && tried.goroot == "" {
751 dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
752 if ctxt.Compiler != "gccgo" {
753 isDir := ctxt.isDir(dir)
754 binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
755 if isDir || binaryOnly {
765 // package was not found
767 format := "\t%s (vendor tree)"
768 for _, dir := range tried.vendor {
769 paths = append(paths, fmt.Sprintf(format, dir))
772 if tried.goroot != "" {
773 paths = append(paths, fmt.Sprintf("\t%s (from $GOROOT)", tried.goroot))
775 paths = append(paths, "\t($GOROOT not set)")
777 format = "\t%s (from $GOPATH)"
778 for _, dir := range tried.gopath {
779 paths = append(paths, fmt.Sprintf(format, dir))
782 if len(tried.gopath) == 0 {
783 paths = append(paths, "\t($GOPATH not set. For more details see: 'go help gopath')")
785 return p, fmt.Errorf("cannot find package %q in any of:\n%s", path, strings.Join(paths, "\n"))
790 p.SrcRoot = ctxt.joinPath(p.Root, "src")
791 p.PkgRoot = ctxt.joinPath(p.Root, "pkg")
792 p.BinDir = ctxt.joinPath(p.Root, "bin")
794 // Always set PkgTargetRoot. It might be used when building in shared
796 p.PkgTargetRoot = ctxt.joinPath(p.Root, pkgtargetroot)
798 // Set the install target if applicable.
799 if !p.Goroot || (installgoroot.Value() == "all" && p.ImportPath != "unsafe" && p.ImportPath != "builtin") {
801 installgoroot.IncNonDefault()
803 p.PkgObj = ctxt.joinPath(p.Root, pkga)
808 // If it's a local import path, by the time we get here, we still haven't checked
809 // that p.Dir directory exists. This is the right time to do that check.
810 // We can't do it earlier, because we want to gather partial information for the
811 // non-nil *Package returned when an error occurs.
812 // We need to do this before we return early on FindOnly flag.
813 if IsLocalImport(path) && !ctxt.isDir(p.Dir) {
814 if ctxt.Compiler == "gccgo" && p.Goroot {
815 // gccgo has no sources for GOROOT packages.
819 // package was not found
820 return p, fmt.Errorf("cannot find package %q in:\n\t%s", p.ImportPath, p.Dir)
823 if mode&FindOnly != 0 {
826 if binaryOnly && (mode&AllowBinary) != 0 {
830 if ctxt.Compiler == "gccgo" && p.Goroot {
831 // gccgo has no sources for GOROOT packages.
835 dirs, err := ctxt.readDir(p.Dir)
841 badGoFiles := make(map[string]bool)
842 badGoFile := func(name string, err error) {
843 if badGoError == nil {
846 if !badGoFiles[name] {
847 p.InvalidGoFiles = append(p.InvalidGoFiles, name)
848 badGoFiles[name] = true
852 var Sfiles []string // files with ".S"(capital S)/.sx(capital s equivalent for case insensitive filesystems)
853 var firstFile, firstCommentFile string
854 embedPos := make(map[string][]token.Position)
855 testEmbedPos := make(map[string][]token.Position)
856 xTestEmbedPos := make(map[string][]token.Position)
857 importPos := make(map[string][]token.Position)
858 testImportPos := make(map[string][]token.Position)
859 xTestImportPos := make(map[string][]token.Position)
860 allTags := make(map[string]bool)
861 fset := token.NewFileSet()
862 for _, d := range dirs {
866 if d.Type() == fs.ModeSymlink {
867 if ctxt.isDir(ctxt.joinPath(p.Dir, d.Name())) {
868 // Symlinks to directories are not source files.
876 info, err := ctxt.matchFile(p.Dir, name, allTags, &p.BinaryOnly, fset)
877 if err != nil && strings.HasSuffix(name, ".go") {
882 if strings.HasPrefix(name, "_") || strings.HasPrefix(name, ".") {
883 // not due to build constraints - don't report
884 } else if ext == ".go" {
885 p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
886 } else if fileListForExt(p, ext) != nil {
887 p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, name)
892 // Going to save the file. For non-Go files, can stop here.
897 // special case for cgo, handled at end
898 Sfiles = append(Sfiles, name)
901 if list := fileListForExt(p, ext); list != nil {
902 *list = append(*list, name)
907 data, filename := info.header, info.name
909 if info.parseErr != nil {
910 badGoFile(name, info.parseErr)
911 // Fall through: we might still have a partial AST in info.parsed,
912 // and we want to list files with parse errors anyway.
916 if info.parsed != nil {
917 pkg = info.parsed.Name.Name
918 if pkg == "documentation" {
919 p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
924 isTest := strings.HasSuffix(name, "_test.go")
926 if isTest && strings.HasSuffix(pkg, "_test") && p.Name != pkg {
928 pkg = pkg[:len(pkg)-len("_test")]
934 } else if pkg != p.Name {
935 // TODO(#45999): The choice of p.Name is arbitrary based on file iteration
936 // order. Instead of resolving p.Name arbitrarily, we should clear out the
937 // existing name and mark the existing files as also invalid.
938 badGoFile(name, &MultiplePackageError{
940 Packages: []string{p.Name, pkg},
941 Files: []string{firstFile, name},
944 // Grab the first package comment as docs, provided it is not from a test file.
945 if info.parsed != nil && info.parsed.Doc != nil && p.Doc == "" && !isTest && !isXTest {
946 p.Doc = doc.Synopsis(info.parsed.Doc.Text())
949 if mode&ImportComment != 0 {
950 qcom, line := findImportComment(data)
952 com, err := strconv.Unquote(qcom)
954 badGoFile(name, fmt.Errorf("%s:%d: cannot parse import comment", filename, line))
955 } else if p.ImportComment == "" {
956 p.ImportComment = com
957 firstCommentFile = name
958 } else if p.ImportComment != com {
959 badGoFile(name, fmt.Errorf("found import comments %q (%s) and %q (%s) in %s", p.ImportComment, firstCommentFile, com, name, p.Dir))
964 // Record imports and information about cgo.
966 for _, imp := range info.imports {
969 badGoFile(name, fmt.Errorf("use of cgo in test %s not supported", filename))
974 if err := ctxt.saveCgo(filename, p, imp.doc); err != nil {
981 var fileList *[]string
982 var importMap, embedMap map[string][]token.Position
983 var directives *[]Directive
986 allTags["cgo"] = true
988 fileList = &p.CgoFiles
989 importMap = importPos
991 directives = &p.Directives
993 // Ignore imports and embeds from cgo files if cgo is disabled.
994 fileList = &p.IgnoredGoFiles
997 fileList = &p.XTestGoFiles
998 importMap = xTestImportPos
999 embedMap = xTestEmbedPos
1000 directives = &p.XTestDirectives
1002 fileList = &p.TestGoFiles
1003 importMap = testImportPos
1004 embedMap = testEmbedPos
1005 directives = &p.TestDirectives
1007 fileList = &p.GoFiles
1008 importMap = importPos
1010 directives = &p.Directives
1012 *fileList = append(*fileList, name)
1013 if importMap != nil {
1014 for _, imp := range info.imports {
1015 importMap[imp.path] = append(importMap[imp.path], fset.Position(imp.pos))
1018 if embedMap != nil {
1019 for _, emb := range info.embeds {
1020 embedMap[emb.pattern] = append(embedMap[emb.pattern], emb.pos)
1023 if directives != nil {
1024 *directives = append(*directives, info.directives...)
1028 for tag := range allTags {
1029 p.AllTags = append(p.AllTags, tag)
1031 sort.Strings(p.AllTags)
1033 p.EmbedPatterns, p.EmbedPatternPos = cleanDecls(embedPos)
1034 p.TestEmbedPatterns, p.TestEmbedPatternPos = cleanDecls(testEmbedPos)
1035 p.XTestEmbedPatterns, p.XTestEmbedPatternPos = cleanDecls(xTestEmbedPos)
1037 p.Imports, p.ImportPos = cleanDecls(importPos)
1038 p.TestImports, p.TestImportPos = cleanDecls(testImportPos)
1039 p.XTestImports, p.XTestImportPos = cleanDecls(xTestImportPos)
1041 // add the .S/.sx files only if we are using cgo
1042 // (which means gcc will compile them).
1043 // The standard assemblers expect .s files.
1044 if len(p.CgoFiles) > 0 {
1045 p.SFiles = append(p.SFiles, Sfiles...)
1046 sort.Strings(p.SFiles)
1048 p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, Sfiles...)
1049 sort.Strings(p.IgnoredOtherFiles)
1052 if badGoError != nil {
1053 return p, badGoError
1055 if len(p.GoFiles)+len(p.CgoFiles)+len(p.TestGoFiles)+len(p.XTestGoFiles) == 0 {
1056 return p, &NoGoError{p.Dir}
1061 func fileListForExt(p *Package, ext string) *[]string {
1065 case ".cc", ".cpp", ".cxx":
1069 case ".h", ".hh", ".hpp", ".hxx":
1071 case ".f", ".F", ".for", ".f90":
1073 case ".s", ".S", ".sx":
1078 return &p.SwigCXXFiles
1085 func uniq(list []string) []string {
1089 out := make([]string, len(list))
1093 for _, x := range out {
1094 if len(uniq) == 0 || uniq[len(uniq)-1] != x {
1095 uniq = append(uniq, x)
1101 var errNoModules = errors.New("not using modules")
1103 // importGo checks whether it can use the go command to find the directory for path.
1104 // If using the go command is not appropriate, importGo returns errNoModules.
1105 // Otherwise, importGo tries using the go command and reports whether that succeeded.
1106 // Using the go command lets build.Import and build.Context.Import find code
1107 // in Go modules. In the long term we want tools to use go/packages (currently golang.org/x/tools/go/packages),
1108 // which will also use the go command.
1109 // Invoking the go command here is not very efficient in that it computes information
1110 // about the requested package and all dependencies and then only reports about the requested package.
1111 // Then we reinvoke it for every dependency. But this is still better than not working at all.
1112 // See golang.org/issue/26504.
1113 func (ctxt *Context) importGo(p *Package, path, srcDir string, mode ImportMode) error {
1114 // To invoke the go command,
1115 // we must not being doing special things like AllowBinary or IgnoreVendor,
1116 // and all the file system callbacks must be nil (we're meant to use the local file system).
1117 if mode&AllowBinary != 0 || mode&IgnoreVendor != 0 ||
1118 ctxt.JoinPath != nil || ctxt.SplitPathList != nil || ctxt.IsAbsPath != nil || ctxt.IsDir != nil || ctxt.HasSubdir != nil || ctxt.ReadDir != nil || ctxt.OpenFile != nil || !equal(ctxt.ToolTags, defaultToolTags) || !equal(ctxt.ReleaseTags, defaultReleaseTags) {
1122 // If ctxt.GOROOT is not set, we don't know which go command to invoke,
1123 // and even if we did we might return packages in GOROOT that we wouldn't otherwise find
1124 // (because we don't know to search in 'go env GOROOT' otherwise).
1125 if ctxt.GOROOT == "" {
1129 // Predict whether module aware mode is enabled by checking the value of
1130 // GO111MODULE and looking for a go.mod file in the source directory or
1131 // one of its parents. Running 'go env GOMOD' in the source directory would
1132 // give a canonical answer, but we'd prefer not to execute another command.
1133 go111Module := os.Getenv("GO111MODULE")
1134 switch go111Module {
1137 default: // "", "on", "auto", anything else
1138 // Maybe use modules.
1142 var absSrcDir string
1143 if filepath.IsAbs(srcDir) {
1145 } else if ctxt.Dir != "" {
1146 return fmt.Errorf("go/build: Dir is non-empty, so relative srcDir is not allowed: %v", srcDir)
1148 // Find the absolute source directory. hasSubdir does not handle
1149 // relative paths (and can't because the callbacks don't support this).
1151 absSrcDir, err = filepath.Abs(srcDir)
1157 // If the source directory is in GOROOT, then the in-process code works fine
1158 // and we should keep using it. Moreover, the 'go list' approach below doesn't
1159 // take standard-library vendoring into account and will fail.
1160 if _, ok := ctxt.hasSubdir(filepath.Join(ctxt.GOROOT, "src"), absSrcDir); ok {
1165 // For efficiency, if path is a standard library package, let the usual lookup code handle it.
1166 if dir := ctxt.joinPath(ctxt.GOROOT, "src", path); ctxt.isDir(dir) {
1170 // If GO111MODULE=auto, look to see if there is a go.mod.
1171 // Since go1.13, it doesn't matter if we're inside GOPATH.
1172 if go111Module == "auto" {
1178 parent, err = os.Getwd()
1180 // A nonexistent working directory can't be in a module.
1184 parent, err = filepath.Abs(ctxt.Dir)
1186 // If the caller passed a bogus Dir explicitly, that's materially
1187 // different from not having modules enabled.
1192 if f, err := ctxt.openFile(ctxt.joinPath(parent, "go.mod")); err == nil {
1193 buf := make([]byte, 100)
1194 _, err := f.Read(buf)
1196 if err == nil || err == io.EOF {
1197 // go.mod exists and is readable (is a file, not a directory).
1201 d := filepath.Dir(parent)
1202 if len(d) >= len(parent) {
1203 return errNoModules // reached top of file system, no go.mod
1209 goCmd := filepath.Join(ctxt.GOROOT, "bin", "go")
1210 cmd := exec.Command(goCmd, "list", "-e", "-compiler="+ctxt.Compiler, "-tags="+strings.Join(ctxt.BuildTags, ","), "-installsuffix="+ctxt.InstallSuffix, "-f={{.Dir}}\n{{.ImportPath}}\n{{.Root}}\n{{.Goroot}}\n{{if .Error}}{{.Error}}{{end}}\n", "--", path)
1216 var stdout, stderr strings.Builder
1217 cmd.Stdout = &stdout
1218 cmd.Stderr = &stderr
1221 if ctxt.CgoEnabled {
1224 cmd.Env = append(cmd.Environ(),
1226 "GOARCH="+ctxt.GOARCH,
1227 "GOROOT="+ctxt.GOROOT,
1228 "GOPATH="+ctxt.GOPATH,
1232 if err := cmd.Run(); err != nil {
1233 return fmt.Errorf("go/build: go list %s: %v\n%s\n", path, err, stderr.String())
1236 f := strings.SplitN(stdout.String(), "\n", 5)
1238 return fmt.Errorf("go/build: importGo %s: unexpected output:\n%s\n", path, stdout.String())
1241 errStr := strings.TrimSpace(f[4])
1242 if errStr != "" && dir == "" {
1243 // If 'go list' could not locate the package (dir is empty),
1244 // return the same error that 'go list' reported.
1245 return errors.New(errStr)
1248 // If 'go list' did locate the package, ignore the error.
1249 // It was probably related to loading source files, and we'll
1250 // encounter it ourselves shortly if the FindOnly flag isn't set.
1254 p.Goroot = f[3] == "true"
1258 func equal(x, y []string) bool {
1259 if len(x) != len(y) {
1262 for i, xi := range x {
1270 // hasGoFiles reports whether dir contains any files with names ending in .go.
1271 // For a vendor check we must exclude directories that contain no .go files.
1272 // Otherwise it is not possible to vendor just a/b/c and still import the
1273 // non-vendored a/b. See golang.org/issue/13832.
1274 func hasGoFiles(ctxt *Context, dir string) bool {
1275 ents, _ := ctxt.readDir(dir)
1276 for _, ent := range ents {
1277 if !ent.IsDir() && strings.HasSuffix(ent.Name(), ".go") {
1284 func findImportComment(data []byte) (s string, line int) {
1285 // expect keyword package
1286 word, data := parseWord(data)
1287 if string(word) != "package" {
1291 // expect package name
1292 _, data = parseWord(data)
1294 // now ready for import comment, a // or /* */ comment
1295 // beginning and ending on the current line.
1296 for len(data) > 0 && (data[0] == ' ' || data[0] == '\t' || data[0] == '\r') {
1302 case bytes.HasPrefix(data, slashSlash):
1303 comment, _, _ = bytes.Cut(data[2:], newline)
1304 case bytes.HasPrefix(data, slashStar):
1306 comment, _, ok = bytes.Cut(data[2:], starSlash)
1308 // malformed comment
1311 if bytes.Contains(comment, newline) {
1315 comment = bytes.TrimSpace(comment)
1317 // split comment into `import`, `"pkg"`
1318 word, arg := parseWord(comment)
1319 if string(word) != "import" {
1323 line = 1 + bytes.Count(data[:cap(data)-cap(arg)], newline)
1324 return strings.TrimSpace(string(arg)), line
1328 slashSlash = []byte("//")
1329 slashStar = []byte("/*")
1330 starSlash = []byte("*/")
1331 newline = []byte("\n")
1334 // skipSpaceOrComment returns data with any leading spaces or comments removed.
1335 func skipSpaceOrComment(data []byte) []byte {
1338 case ' ', '\t', '\r', '\n':
1342 if bytes.HasPrefix(data, slashSlash) {
1343 i := bytes.Index(data, newline)
1350 if bytes.HasPrefix(data, slashStar) {
1352 i := bytes.Index(data, starSlash)
1365 // parseWord skips any leading spaces or comments in data
1366 // and then parses the beginning of data as an identifier or keyword,
1367 // returning that word and what remains after the word.
1368 func parseWord(data []byte) (word, rest []byte) {
1369 data = skipSpaceOrComment(data)
1371 // Parse past leading word characters.
1374 r, size := utf8.DecodeRune(rest)
1375 if unicode.IsLetter(r) || '0' <= r && r <= '9' || r == '_' {
1382 word = data[:len(data)-len(rest)]
1390 // MatchFile reports whether the file with the given name in the given directory
1391 // matches the context and would be included in a Package created by ImportDir
1392 // of that directory.
1394 // MatchFile considers the name of the file and may use ctxt.OpenFile to
1395 // read some or all of the file's content.
1396 func (ctxt *Context) MatchFile(dir, name string) (match bool, err error) {
1397 info, err := ctxt.matchFile(dir, name, nil, nil, nil)
1398 return info != nil, err
1401 var dummyPkg Package
1403 // fileInfo records information learned about a file included in a build.
1404 type fileInfo struct {
1405 name string // full name including dir
1410 imports []fileImport
1412 directives []Directive
1415 type fileImport struct {
1418 doc *ast.CommentGroup
1421 type fileEmbed struct {
1426 // matchFile determines whether the file with the given name in the given directory
1427 // should be included in the package being constructed.
1428 // If the file should be included, matchFile returns a non-nil *fileInfo (and a nil error).
1429 // Non-nil errors are reserved for unexpected problems.
1431 // If name denotes a Go program, matchFile reads until the end of the
1432 // imports and returns that section of the file in the fileInfo's header field,
1433 // even though it only considers text until the first non-comment
1434 // for go:build lines.
1436 // If allTags is non-nil, matchFile records any encountered build tag
1437 // by setting allTags[tag] = true.
1438 func (ctxt *Context) matchFile(dir, name string, allTags map[string]bool, binaryOnly *bool, fset *token.FileSet) (*fileInfo, error) {
1439 if strings.HasPrefix(name, "_") ||
1440 strings.HasPrefix(name, ".") {
1444 i := strings.LastIndex(name, ".")
1450 if ext != ".go" && fileListForExt(&dummyPkg, ext) == nil {
1455 if !ctxt.goodOSArchFile(name, allTags) && !ctxt.UseAllFiles {
1459 info := &fileInfo{name: ctxt.joinPath(dir, name), fset: fset}
1461 // binary, no reading
1465 f, err := ctxt.openFile(info.name)
1470 if strings.HasSuffix(name, ".go") {
1471 err = readGoInfo(f, info)
1472 if strings.HasSuffix(name, "_test.go") {
1473 binaryOnly = nil // ignore //go:binary-only-package comments in _test.go files
1476 binaryOnly = nil // ignore //go:binary-only-package comments in non-Go sources
1477 info.header, err = readComments(f)
1481 return info, fmt.Errorf("read %s: %v", info.name, err)
1484 // Look for go:build comments to accept or reject the file.
1485 ok, sawBinaryOnly, err := ctxt.shouldBuild(info.header, allTags)
1487 return nil, fmt.Errorf("%s: %v", name, err)
1489 if !ok && !ctxt.UseAllFiles {
1493 if binaryOnly != nil && sawBinaryOnly {
1500 func cleanDecls(m map[string][]token.Position) ([]string, map[string][]token.Position) {
1501 all := make([]string, 0, len(m))
1502 for path := range m {
1503 all = append(all, path)
1509 // Import is shorthand for Default.Import.
1510 func Import(path, srcDir string, mode ImportMode) (*Package, error) {
1511 return Default.Import(path, srcDir, mode)
1514 // ImportDir is shorthand for Default.ImportDir.
1515 func ImportDir(dir string, mode ImportMode) (*Package, error) {
1516 return Default.ImportDir(dir, mode)
1520 plusBuild = []byte("+build")
1522 goBuildComment = []byte("//go:build")
1524 errMultipleGoBuild = errors.New("multiple //go:build comments")
1527 func isGoBuildComment(line []byte) bool {
1528 if !bytes.HasPrefix(line, goBuildComment) {
1531 line = bytes.TrimSpace(line)
1532 rest := line[len(goBuildComment):]
1533 return len(rest) == 0 || len(bytes.TrimSpace(rest)) < len(rest)
1536 // Special comment denoting a binary-only package.
1537 // See https://golang.org/design/2775-binary-only-packages
1538 // for more about the design of binary-only packages.
1539 var binaryOnlyComment = []byte("//go:binary-only-package")
1541 // shouldBuild reports whether it is okay to use this file,
1542 // The rule is that in the file's leading run of // comments
1543 // and blank lines, which must be followed by a blank line
1544 // (to avoid including a Go package clause doc comment),
1545 // lines beginning with '//go:build' are taken as build directives.
1547 // The file is accepted only if each such line lists something
1548 // matching the file. For example:
1550 // //go:build windows linux
1552 // marks the file as applicable only on Windows and Linux.
1554 // For each build tag it consults, shouldBuild sets allTags[tag] = true.
1556 // shouldBuild reports whether the file should be built
1557 // and whether a //go:binary-only-package comment was found.
1558 func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool) (shouldBuild, binaryOnly bool, err error) {
1559 // Identify leading run of // comments and blank lines,
1560 // which must be followed by a blank line.
1561 // Also identify any //go:build comments.
1562 content, goBuild, sawBinaryOnly, err := parseFileHeader(content)
1564 return false, false, err
1567 // If //go:build line is present, it controls.
1568 // Otherwise fall back to +build processing.
1570 case goBuild != nil:
1571 x, err := constraint.Parse(string(goBuild))
1573 return false, false, fmt.Errorf("parsing //go:build line: %v", err)
1575 shouldBuild = ctxt.eval(x, allTags)
1582 if i := bytes.IndexByte(line, '\n'); i >= 0 {
1583 line, p = line[:i], p[i+1:]
1587 line = bytes.TrimSpace(line)
1588 if !bytes.HasPrefix(line, slashSlash) || !bytes.Contains(line, plusBuild) {
1591 text := string(line)
1592 if !constraint.IsPlusBuild(text) {
1595 if x, err := constraint.Parse(text); err == nil {
1596 if !ctxt.eval(x, allTags) {
1603 return shouldBuild, sawBinaryOnly, nil
1606 func parseFileHeader(content []byte) (trimmed, goBuild []byte, sawBinaryOnly bool, err error) {
1609 ended := false // found non-blank, non-// line, so stopped accepting //go:build lines
1610 inSlashStar := false // in /* */ comment
1615 if i := bytes.IndexByte(line, '\n'); i >= 0 {
1616 line, p = line[:i], p[i+1:]
1620 line = bytes.TrimSpace(line)
1621 if len(line) == 0 && !ended { // Blank line
1622 // Remember position of most recent blank line.
1623 // When we find the first non-blank, non-// line,
1624 // this "end" position marks the latest file position
1625 // where a //go:build line can appear.
1626 // (It must appear _before_ a blank line before the non-blank, non-// line.
1627 // Yes, that's confusing, which is part of why we moved to //go:build lines.)
1628 // Note that ended==false here means that inSlashStar==false,
1629 // since seeing a /* would have set ended==true.
1630 end = len(content) - len(p)
1633 if !bytes.HasPrefix(line, slashSlash) { // Not comment line
1637 if !inSlashStar && isGoBuildComment(line) {
1639 return nil, nil, false, errMultipleGoBuild
1643 if !inSlashStar && bytes.Equal(line, binaryOnlyComment) {
1644 sawBinaryOnly = true
1650 if i := bytes.Index(line, starSlash); i >= 0 {
1652 line = bytes.TrimSpace(line[i+len(starSlash):])
1657 if bytes.HasPrefix(line, slashSlash) {
1660 if bytes.HasPrefix(line, slashStar) {
1662 line = bytes.TrimSpace(line[len(slashStar):])
1665 // Found non-comment text.
1670 return content[:end], goBuild, sawBinaryOnly, nil
1673 // saveCgo saves the information from the #cgo lines in the import "C" comment.
1674 // These lines set CFLAGS, CPPFLAGS, CXXFLAGS and LDFLAGS and pkg-config directives
1675 // that affect the way cgo's C code is built.
1676 func (ctxt *Context) saveCgo(filename string, di *Package, cg *ast.CommentGroup) error {
1678 for _, line := range strings.Split(text, "\n") {
1682 // #cgo [GOOS/GOARCH...] LDFLAGS: stuff
1684 line = strings.TrimSpace(line)
1685 if len(line) < 5 || line[:4] != "#cgo" || (line[4] != ' ' && line[4] != '\t') {
1690 line, argstr, ok := strings.Cut(strings.TrimSpace(line[4:]), ":")
1692 return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
1695 // Parse GOOS/GOARCH stuff.
1696 f := strings.Fields(line)
1698 return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
1701 cond, verb := f[:len(f)-1], f[len(f)-1]
1704 for _, c := range cond {
1705 if ctxt.matchAuto(c, nil) {
1715 args, err := splitQuoted(argstr)
1717 return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
1719 for i, arg := range args {
1720 if arg, ok = expandSrcDir(arg, di.Dir); !ok {
1721 return fmt.Errorf("%s: malformed #cgo argument: %s", filename, arg)
1727 case "CFLAGS", "CPPFLAGS", "CXXFLAGS", "FFLAGS", "LDFLAGS":
1728 // Change relative paths to absolute.
1729 ctxt.makePathsAbsolute(args, di.Dir)
1734 di.CgoCFLAGS = append(di.CgoCFLAGS, args...)
1736 di.CgoCPPFLAGS = append(di.CgoCPPFLAGS, args...)
1738 di.CgoCXXFLAGS = append(di.CgoCXXFLAGS, args...)
1740 di.CgoFFLAGS = append(di.CgoFFLAGS, args...)
1742 di.CgoLDFLAGS = append(di.CgoLDFLAGS, args...)
1744 di.CgoPkgConfig = append(di.CgoPkgConfig, args...)
1746 return fmt.Errorf("%s: invalid #cgo verb: %s", filename, orig)
1752 // expandSrcDir expands any occurrence of ${SRCDIR}, making sure
1753 // the result is safe for the shell.
1754 func expandSrcDir(str string, srcdir string) (string, bool) {
1755 // "\" delimited paths cause safeCgoName to fail
1756 // so convert native paths with a different delimiter
1757 // to "/" before starting (eg: on windows).
1758 srcdir = filepath.ToSlash(srcdir)
1760 chunks := strings.Split(str, "${SRCDIR}")
1761 if len(chunks) < 2 {
1762 return str, safeCgoName(str)
1765 for _, chunk := range chunks {
1766 ok = ok && (chunk == "" || safeCgoName(chunk))
1768 ok = ok && (srcdir == "" || safeCgoName(srcdir))
1769 res := strings.Join(chunks, srcdir)
1770 return res, ok && res != ""
1773 // makePathsAbsolute looks for compiler options that take paths and
1774 // makes them absolute. We do this because through the 1.8 release we
1775 // ran the compiler in the package directory, so any relative -I or -L
1776 // options would be relative to that directory. In 1.9 we changed to
1777 // running the compiler in the build directory, to get consistent
1778 // build results (issue #19964). To keep builds working, we change any
1779 // relative -I or -L options to be absolute.
1781 // Using filepath.IsAbs and filepath.Join here means the results will be
1782 // different on different systems, but that's OK: -I and -L options are
1783 // inherently system-dependent.
1784 func (ctxt *Context) makePathsAbsolute(args []string, srcDir string) {
1786 for i, arg := range args {
1788 if !filepath.IsAbs(arg) {
1789 args[i] = filepath.Join(srcDir, arg)
1792 } else if strings.HasPrefix(arg, "-I") || strings.HasPrefix(arg, "-L") {
1796 if !filepath.IsAbs(arg[2:]) {
1797 args[i] = arg[:2] + filepath.Join(srcDir, arg[2:])
1804 // NOTE: $ is not safe for the shell, but it is allowed here because of linker options like -Wl,$ORIGIN.
1805 // We never pass these arguments to a shell (just to programs we construct argv for), so this should be okay.
1806 // See golang.org/issue/6038.
1807 // The @ is for OS X. See golang.org/issue/13720.
1808 // The % is for Jenkins. See golang.org/issue/16959.
1809 // The ! is because module paths may use them. See golang.org/issue/26716.
1810 // The ~ and ^ are for sr.ht. See golang.org/issue/32260.
1811 const safeString = "+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:$@%! ~^"
1813 func safeCgoName(s string) bool {
1817 for i := 0; i < len(s); i++ {
1818 if c := s[i]; c < utf8.RuneSelf && strings.IndexByte(safeString, c) < 0 {
1825 // splitQuoted splits the string s around each instance of one or more consecutive
1826 // white space characters while taking into account quotes and escaping, and
1827 // returns an array of substrings of s or an empty list if s contains only white space.
1828 // Single quotes and double quotes are recognized to prevent splitting within the
1829 // quoted region, and are removed from the resulting substrings. If a quote in s
1830 // isn't closed err will be set and r will have the unclosed argument as the
1831 // last element. The backslash is used for escaping.
1833 // For example, the following string:
1835 // a b:"c d" 'e''f' "g\""
1837 // Would be parsed as:
1839 // []string{"a", "b:c d", "ef", `g"`}
1840 func splitQuoted(s string) (r []string, err error) {
1842 arg := make([]rune, len(s))
1847 for _, rune := range s {
1854 case quote != '\x00':
1859 case rune == '"' || rune == '\'':
1863 case unicode.IsSpace(rune):
1864 if quoted || i > 0 {
1866 args = append(args, string(arg[:i]))
1874 if quoted || i > 0 {
1875 args = append(args, string(arg[:i]))
1878 err = errors.New("unclosed quote")
1880 err = errors.New("unfinished escaping")
1885 // matchAuto interprets text as either a +build or //go:build expression (whichever works),
1886 // reporting whether the expression matches the build context.
1888 // matchAuto is only used for testing of tag evaluation
1889 // and in #cgo lines, which accept either syntax.
1890 func (ctxt *Context) matchAuto(text string, allTags map[string]bool) bool {
1891 if strings.ContainsAny(text, "&|()") {
1892 text = "//go:build " + text
1894 text = "// +build " + text
1896 x, err := constraint.Parse(text)
1900 return ctxt.eval(x, allTags)
1903 func (ctxt *Context) eval(x constraint.Expr, allTags map[string]bool) bool {
1904 return x.Eval(func(tag string) bool { return ctxt.matchTag(tag, allTags) })
1907 // matchTag reports whether the name is one of:
1909 // cgo (if cgo is enabled)
1913 // linux (if GOOS = android)
1914 // solaris (if GOOS = illumos)
1915 // darwin (if GOOS = ios)
1916 // unix (if this is a Unix GOOS)
1917 // boringcrypto (if GOEXPERIMENT=boringcrypto is enabled)
1918 // tag (if tag is listed in ctxt.BuildTags, ctxt.ToolTags, or ctxt.ReleaseTags)
1920 // It records all consulted tags in allTags.
1921 func (ctxt *Context) matchTag(name string, allTags map[string]bool) bool {
1923 allTags[name] = true
1927 if ctxt.CgoEnabled && name == "cgo" {
1930 if name == ctxt.GOOS || name == ctxt.GOARCH || name == ctxt.Compiler {
1933 if ctxt.GOOS == "android" && name == "linux" {
1936 if ctxt.GOOS == "illumos" && name == "solaris" {
1939 if ctxt.GOOS == "ios" && name == "darwin" {
1942 if name == "unix" && unixOS[ctxt.GOOS] {
1945 if name == "boringcrypto" {
1946 name = "goexperiment.boringcrypto" // boringcrypto is an old name for goexperiment.boringcrypto
1950 for _, tag := range ctxt.BuildTags {
1955 for _, tag := range ctxt.ToolTags {
1960 for _, tag := range ctxt.ReleaseTags {
1969 // goodOSArchFile returns false if the name contains a $GOOS or $GOARCH
1970 // suffix which does not match the current system.
1971 // The recognized name formats are:
1975 // name_$(GOOS)_$(GOARCH).*
1976 // name_$(GOOS)_test.*
1977 // name_$(GOARCH)_test.*
1978 // name_$(GOOS)_$(GOARCH)_test.*
1981 // if GOOS=android, then files with GOOS=linux are also matched.
1982 // if GOOS=illumos, then files with GOOS=solaris are also matched.
1983 // if GOOS=ios, then files with GOOS=darwin are also matched.
1984 func (ctxt *Context) goodOSArchFile(name string, allTags map[string]bool) bool {
1985 name, _, _ = strings.Cut(name, ".")
1987 // Before Go 1.4, a file called "linux.go" would be equivalent to having a
1988 // build tag "linux" in that file. For Go 1.4 and beyond, we require this
1989 // auto-tagging to apply only to files with a non-empty prefix, so
1990 // "foo_linux.go" is tagged but "linux.go" is not. This allows new operating
1991 // systems, such as android, to arrive without breaking existing code with
1992 // innocuous source code in "android.go". The easiest fix: cut everything
1993 // in the name before the initial _.
1994 i := strings.Index(name, "_")
1998 name = name[i:] // ignore everything before first _
2000 l := strings.Split(name, "_")
2001 if n := len(l); n > 0 && l[n-1] == "test" {
2005 if n >= 2 && knownOS[l[n-2]] && knownArch[l[n-1]] {
2007 // In case we short-circuit on l[n-1].
2008 allTags[l[n-2]] = true
2010 return ctxt.matchTag(l[n-1], allTags) && ctxt.matchTag(l[n-2], allTags)
2012 if n >= 1 && (knownOS[l[n-1]] || knownArch[l[n-1]]) {
2013 return ctxt.matchTag(l[n-1], allTags)
2018 // ToolDir is the directory containing build tools.
2019 var ToolDir = getToolDir()
2021 // IsLocalImport reports whether the import path is
2022 // a local import path, like ".", "..", "./foo", or "../foo".
2023 func IsLocalImport(path string) bool {
2024 return path == "." || path == ".." ||
2025 strings.HasPrefix(path, "./") || strings.HasPrefix(path, "../")
2028 // ArchChar returns "?" and an error.
2029 // In earlier versions of Go, the returned string was used to derive
2030 // the compiler and linker tool names, the default object file suffix,
2031 // and the default linker output name. As of Go 1.5, those strings
2032 // no longer vary by architecture; they are compile, link, .o, and a.out, respectively.
2033 func ArchChar(goarch string) (string, error) {
2034 return "?", errors.New("architecture letter no longer used")