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.
16 exec "internal/execabs"
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 +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 +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 ioutil.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 if !strings.HasPrefix(dir, root) {
186 return filepath.ToSlash(dir[len(root):]), true
189 // readDir calls ctxt.ReadDir (if not nil) or else ioutil.ReadDir.
190 func (ctxt *Context) readDir(path string) ([]fs.FileInfo, error) {
191 if f := ctxt.ReadDir; f != nil {
194 // TODO: use os.ReadDir
195 return ioutil.ReadDir(path)
198 // openFile calls ctxt.OpenFile (if not nil) or else os.Open.
199 func (ctxt *Context) openFile(path string) (io.ReadCloser, error) {
200 if fn := ctxt.OpenFile; fn != nil {
204 f, err := os.Open(path)
206 return nil, err // nil interface
211 // isFile determines whether path is a file by trying to open it.
212 // It reuses openFile instead of adding another function to the
214 func (ctxt *Context) isFile(path string) bool {
215 f, err := ctxt.openFile(path)
223 // gopath returns the list of Go path directories.
224 func (ctxt *Context) gopath() []string {
226 for _, p := range ctxt.splitPathList(ctxt.GOPATH) {
227 if p == "" || p == ctxt.GOROOT {
228 // Empty paths are uninteresting.
229 // If the path is the GOROOT, ignore it.
230 // People sometimes set GOPATH=$GOROOT.
231 // Do not get confused by this common mistake.
234 if strings.HasPrefix(p, "~") {
235 // Path segments starting with ~ on Unix are almost always
236 // users who have incorrectly quoted ~ while setting GOPATH,
237 // preventing it from expanding to $HOME.
238 // The situation is made more confusing by the fact that
239 // bash allows quoted ~ in $PATH (most shells do not).
240 // Do not get confused by this, and do not try to use the path.
241 // It does not exist, and printing errors about it confuses
242 // those users even more, because they think "sure ~ exists!".
243 // The go command diagnoses this situation and prints a
245 // On Windows, ~ is used in short names, such as c:\progra~1
246 // for c:\program files.
254 // SrcDirs returns a list of package source root directories.
255 // It draws from the current Go root and Go path but omits directories
256 // that do not exist.
257 func (ctxt *Context) SrcDirs() []string {
259 if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
260 dir := ctxt.joinPath(ctxt.GOROOT, "src")
262 all = append(all, dir)
265 for _, p := range ctxt.gopath() {
266 dir := ctxt.joinPath(p, "src")
268 all = append(all, dir)
274 // Default is the default Context for builds.
275 // It uses the GOARCH, GOOS, GOROOT, and GOPATH environment variables
276 // if set, or else the compiled code's GOARCH, GOOS, and GOROOT.
277 var Default Context = defaultContext()
279 func defaultGOPATH() string {
281 if runtime.GOOS == "windows" {
283 } else if runtime.GOOS == "plan9" {
286 if home := os.Getenv(env); home != "" {
287 def := filepath.Join(home, "go")
288 if filepath.Clean(def) == filepath.Clean(runtime.GOROOT()) {
289 // Don't set the default GOPATH to GOROOT,
290 // as that will trigger warnings from the go tool.
298 var defaultToolTags, defaultReleaseTags []string
300 func defaultContext() Context {
303 c.GOARCH = buildcfg.GOARCH
304 c.GOOS = buildcfg.GOOS
305 if goroot := runtime.GOROOT(); goroot != "" {
306 c.GOROOT = filepath.Clean(goroot)
308 c.GOPATH = envOr("GOPATH", defaultGOPATH())
309 c.Compiler = runtime.Compiler
311 // For each experiment that has been enabled in the toolchain, define a
312 // build tag with the same name but prefixed by "goexperiment." which can be
313 // used for compiling alternative files for the experiment. This allows
314 // changes for the experiment, like extra struct fields in the runtime,
315 // without affecting the base non-experiment code at all.
316 for _, exp := range buildcfg.Experiment.Enabled() {
317 c.ToolTags = append(c.ToolTags, "goexperiment."+exp)
319 defaultToolTags = append([]string{}, c.ToolTags...) // our own private copy
321 // Each major Go release in the Go 1.x series adds a new
322 // "go1.x" release tag. That is, the go1.x tag is present in
323 // all releases >= Go 1.x. Code that requires Go 1.x or later
324 // should say "+build go1.x", and code that should only be
325 // built before Go 1.x (perhaps it is the stub to use in that
326 // case) should say "+build !go1.x".
327 // The last element in ReleaseTags is the current release.
328 for i := 1; i <= goversion.Version; i++ {
329 c.ReleaseTags = append(c.ReleaseTags, "go1."+strconv.Itoa(i))
332 defaultReleaseTags = append([]string{}, c.ReleaseTags...) // our own private copy
334 env := os.Getenv("CGO_ENABLED")
336 env = defaultCGO_ENABLED
344 // cgo must be explicitly enabled for cross compilation builds
345 if runtime.GOARCH == c.GOARCH && runtime.GOOS == c.GOOS {
346 c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
355 func envOr(name, def string) string {
363 // An ImportMode controls the behavior of the Import method.
367 // If FindOnly is set, Import stops after locating the directory
368 // that should contain the sources for a package. It does not
369 // read any files in the directory.
370 FindOnly ImportMode = 1 << iota
372 // If AllowBinary is set, Import can be satisfied by a compiled
373 // package object without corresponding sources.
376 // The supported way to create a compiled-only package is to
377 // write source code containing a //go:binary-only-package comment at
378 // the top of the file. Such a package will be recognized
379 // regardless of this flag setting (because it has source code)
380 // and will have BinaryOnly set to true in the returned Package.
383 // If ImportComment is set, parse import comments on package statements.
384 // Import returns an error if it finds a comment it cannot understand
385 // or finds conflicting comments in multiple source files.
386 // See golang.org/s/go14customimport for more information.
389 // By default, Import searches vendor directories
390 // that apply in the given source directory before searching
391 // the GOROOT and GOPATH roots.
392 // If an Import finds and returns a package using a vendor
393 // directory, the resulting ImportPath is the complete path
394 // to the package, including the path elements leading up
395 // to and including "vendor".
396 // For example, if Import("y", "x/subdir", 0) finds
397 // "x/vendor/y", the returned package's ImportPath is "x/vendor/y",
399 // See golang.org/s/go15vendor for more information.
401 // Setting IgnoreVendor ignores vendor directories.
403 // In contrast to the package's ImportPath,
404 // the returned package's Imports, TestImports, and XTestImports
405 // are always the exact import paths from the source files:
406 // Import makes no attempt to resolve or check those paths.
410 // A Package describes the Go package found in a directory.
411 type Package struct {
412 Dir string // directory containing package sources
413 Name string // package name
414 ImportComment string // path in import comment on package statement
415 Doc string // documentation synopsis
416 ImportPath string // import path of package ("" if unknown)
417 Root string // root of Go tree where this package lives
418 SrcRoot string // package source root directory ("" if unknown)
419 PkgRoot string // package install root directory ("" if unknown)
420 PkgTargetRoot string // architecture dependent install root directory ("" if unknown)
421 BinDir string // command install directory ("" if unknown)
422 Goroot bool // package found in Go root
423 PkgObj string // installed .a file
424 AllTags []string // tags that can influence file selection in this directory
425 ConflictDir string // this directory shadows Dir in $GOPATH
426 BinaryOnly bool // cannot be rebuilt from source (has //go:binary-only-package comment)
429 GoFiles []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
430 CgoFiles []string // .go source files that import "C"
431 IgnoredGoFiles []string // .go source files ignored for this build (including ignored _test.go files)
432 InvalidGoFiles []string // .go source files with detected problems (parse error, wrong package name, and so on)
433 IgnoredOtherFiles []string // non-.go source files ignored for this build
434 CFiles []string // .c source files
435 CXXFiles []string // .cc, .cpp and .cxx source files
436 MFiles []string // .m (Objective-C) source files
437 HFiles []string // .h, .hh, .hpp and .hxx source files
438 FFiles []string // .f, .F, .for and .f90 Fortran source files
439 SFiles []string // .s source files
440 SwigFiles []string // .swig files
441 SwigCXXFiles []string // .swigcxx files
442 SysoFiles []string // .syso system object files to add to archive
445 CgoCFLAGS []string // Cgo CFLAGS directives
446 CgoCPPFLAGS []string // Cgo CPPFLAGS directives
447 CgoCXXFLAGS []string // Cgo CXXFLAGS directives
448 CgoFFLAGS []string // Cgo FFLAGS directives
449 CgoLDFLAGS []string // Cgo LDFLAGS directives
450 CgoPkgConfig []string // Cgo pkg-config directives
453 TestGoFiles []string // _test.go files in package
454 XTestGoFiles []string // _test.go files outside package
456 // Dependency information
457 Imports []string // import paths from GoFiles, CgoFiles
458 ImportPos map[string][]token.Position // line information for Imports
459 TestImports []string // import paths from TestGoFiles
460 TestImportPos map[string][]token.Position // line information for TestImports
461 XTestImports []string // import paths from XTestGoFiles
462 XTestImportPos map[string][]token.Position // line information for XTestImports
464 // //go:embed patterns found in Go source files
465 // For example, if a source file says
467 // then the list will contain those two strings as separate entries.
468 // (See package embed for more details about //go:embed.)
469 EmbedPatterns []string // patterns from GoFiles, CgoFiles
470 EmbedPatternPos map[string][]token.Position // line information for EmbedPatterns
471 TestEmbedPatterns []string // patterns from TestGoFiles
472 TestEmbedPatternPos map[string][]token.Position // line information for TestEmbedPatterns
473 XTestEmbedPatterns []string // patterns from XTestGoFiles
474 XTestEmbedPatternPos map[string][]token.Position // line information for XTestEmbedPatternPos
477 // IsCommand reports whether the package is considered a
478 // command to be installed (not just a library).
479 // Packages named "main" are treated as commands.
480 func (p *Package) IsCommand() bool {
481 return p.Name == "main"
484 // ImportDir is like Import but processes the Go package found in
485 // the named directory.
486 func (ctxt *Context) ImportDir(dir string, mode ImportMode) (*Package, error) {
487 return ctxt.Import(".", dir, mode)
490 // NoGoError is the error used by Import to describe a directory
491 // containing no buildable Go source files. (It may still contain
492 // test files, files hidden by build tags, and so on.)
493 type NoGoError struct {
497 func (e *NoGoError) Error() string {
498 return "no buildable Go source files in " + e.Dir
501 // MultiplePackageError describes a directory containing
502 // multiple buildable Go source files for multiple packages.
503 type MultiplePackageError struct {
504 Dir string // directory containing files
505 Packages []string // package names found
506 Files []string // corresponding files: Files[i] declares package Packages[i]
509 func (e *MultiplePackageError) Error() string {
510 // Error string limited to two entries for compatibility.
511 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)
514 func nameExt(name string) string {
515 i := strings.LastIndex(name, ".")
522 // Import returns details about the Go package named by the import path,
523 // interpreting local import paths relative to the srcDir directory.
524 // If the path is a local import path naming a package that can be imported
525 // using a standard import path, the returned package will set p.ImportPath
528 // In the directory containing the package, .go, .c, .h, and .s files are
529 // considered part of the package except for:
531 // - .go files in package documentation
532 // - files starting with _ or . (likely editor temporary files)
533 // - files with build constraints not satisfied by the context
535 // If an error occurs, Import returns a non-nil error and a non-nil
536 // *Package containing partial information.
538 func (ctxt *Context) Import(path string, srcDir string, mode ImportMode) (*Package, error) {
543 return p, fmt.Errorf("import %q: invalid import path", path)
546 var pkgtargetroot string
550 if ctxt.InstallSuffix != "" {
551 suffix = "_" + ctxt.InstallSuffix
553 switch ctxt.Compiler {
555 pkgtargetroot = "pkg/gccgo_" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
557 pkgtargetroot = "pkg/" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
559 // Save error for end of function.
560 pkgerr = fmt.Errorf("import %q: unknown compiler %q", path, ctxt.Compiler)
563 switch ctxt.Compiler {
565 dir, elem := pathpkg.Split(p.ImportPath)
566 pkga = pkgtargetroot + "/" + dir + "lib" + elem + ".a"
568 pkga = pkgtargetroot + "/" + p.ImportPath + ".a"
574 if IsLocalImport(path) {
575 pkga = "" // local imports have no installed path
577 return p, fmt.Errorf("import %q: import relative to unknown directory", path)
579 if !ctxt.isAbsPath(path) {
580 p.Dir = ctxt.joinPath(srcDir, path)
582 // p.Dir directory may or may not exist. Gather partial information first, check if it exists later.
583 // Determine canonical import path, if any.
584 // Exclude results where the import path would include /testdata/.
585 inTestdata := func(sub string) bool {
586 return strings.Contains(sub, "/testdata/") || strings.HasSuffix(sub, "/testdata") || strings.HasPrefix(sub, "testdata/") || sub == "testdata"
588 if ctxt.GOROOT != "" {
589 root := ctxt.joinPath(ctxt.GOROOT, "src")
590 if sub, ok := ctxt.hasSubdir(root, p.Dir); ok && !inTestdata(sub) {
594 setPkga() // p.ImportPath changed
599 for i, root := range all {
600 rootsrc := ctxt.joinPath(root, "src")
601 if sub, ok := ctxt.hasSubdir(rootsrc, p.Dir); ok && !inTestdata(sub) {
602 // We found a potential import path for dir,
603 // but check that using it wouldn't find something
605 if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
606 if dir := ctxt.joinPath(ctxt.GOROOT, "src", sub); ctxt.isDir(dir) {
611 for _, earlyRoot := range all[:i] {
612 if dir := ctxt.joinPath(earlyRoot, "src", sub); ctxt.isDir(dir) {
618 // sub would not name some other directory instead of this one.
622 setPkga() // p.ImportPath changed
626 // It's okay that we didn't find a root containing dir.
627 // Keep going with the information we have.
629 if strings.HasPrefix(path, "/") {
630 return p, fmt.Errorf("import %q: cannot import absolute path", path)
633 if err := ctxt.importGo(p, path, srcDir, mode); err == nil {
635 } else if err != errNoModules {
639 gopath := ctxt.gopath() // needed twice below; avoid computing many times
641 // tried records the location of unsuccessful package lookups
648 // Vendor directories get first chance to satisfy import.
649 if mode&IgnoreVendor == 0 && srcDir != "" {
650 searchVendor := func(root string, isGoroot bool) bool {
651 sub, ok := ctxt.hasSubdir(root, srcDir)
652 if !ok || !strings.HasPrefix(sub, "src/") || strings.Contains(sub, "/testdata/") {
656 vendor := ctxt.joinPath(root, sub, "vendor")
657 if ctxt.isDir(vendor) {
658 dir := ctxt.joinPath(vendor, path)
659 if ctxt.isDir(dir) && hasGoFiles(ctxt, dir) {
661 p.ImportPath = strings.TrimPrefix(pathpkg.Join(sub, "vendor", path), "src/")
664 setPkga() // p.ImportPath changed
667 tried.vendor = append(tried.vendor, dir)
669 i := strings.LastIndex(sub, "/")
677 if ctxt.Compiler != "gccgo" && ctxt.GOROOT != "" && searchVendor(ctxt.GOROOT, true) {
680 for _, root := range gopath {
681 if searchVendor(root, false) {
687 // Determine directory from import path.
688 if ctxt.GOROOT != "" {
689 // If the package path starts with "vendor/", only search GOROOT before
690 // GOPATH if the importer is also within GOROOT. That way, if the user has
691 // vendored in a package that is subsequently included in the standard
692 // distribution, they'll continue to pick up their own vendored copy.
693 gorootFirst := srcDir == "" || !strings.HasPrefix(path, "vendor/")
695 _, gorootFirst = ctxt.hasSubdir(ctxt.GOROOT, srcDir)
698 dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
699 if ctxt.Compiler != "gccgo" {
700 isDir := ctxt.isDir(dir)
701 binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
702 if isDir || binaryOnly {
711 if ctxt.Compiler == "gccgo" && goroot.IsStandardPackage(ctxt.GOROOT, ctxt.Compiler, path) {
712 p.Dir = ctxt.joinPath(ctxt.GOROOT, "src", path)
718 for _, root := range gopath {
719 dir := ctxt.joinPath(root, "src", path)
720 isDir := ctxt.isDir(dir)
721 binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(root, pkga))
722 if isDir || binaryOnly {
727 tried.gopath = append(tried.gopath, dir)
730 // If we tried GOPATH first due to a "vendor/" prefix, fall back to GOPATH.
731 // That way, the user can still get useful results from 'go list' for
732 // standard-vendored paths passed on the command line.
733 if ctxt.GOROOT != "" && tried.goroot == "" {
734 dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
735 if ctxt.Compiler != "gccgo" {
736 isDir := ctxt.isDir(dir)
737 binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
738 if isDir || binaryOnly {
748 // package was not found
750 format := "\t%s (vendor tree)"
751 for _, dir := range tried.vendor {
752 paths = append(paths, fmt.Sprintf(format, dir))
755 if tried.goroot != "" {
756 paths = append(paths, fmt.Sprintf("\t%s (from $GOROOT)", tried.goroot))
758 paths = append(paths, "\t($GOROOT not set)")
760 format = "\t%s (from $GOPATH)"
761 for _, dir := range tried.gopath {
762 paths = append(paths, fmt.Sprintf(format, dir))
765 if len(tried.gopath) == 0 {
766 paths = append(paths, "\t($GOPATH not set. For more details see: 'go help gopath')")
768 return p, fmt.Errorf("cannot find package %q in any of:\n%s", path, strings.Join(paths, "\n"))
773 p.SrcRoot = ctxt.joinPath(p.Root, "src")
774 p.PkgRoot = ctxt.joinPath(p.Root, "pkg")
775 p.BinDir = ctxt.joinPath(p.Root, "bin")
777 p.PkgTargetRoot = ctxt.joinPath(p.Root, pkgtargetroot)
778 p.PkgObj = ctxt.joinPath(p.Root, pkga)
782 // If it's a local import path, by the time we get here, we still haven't checked
783 // that p.Dir directory exists. This is the right time to do that check.
784 // We can't do it earlier, because we want to gather partial information for the
785 // non-nil *Package returned when an error occurs.
786 // We need to do this before we return early on FindOnly flag.
787 if IsLocalImport(path) && !ctxt.isDir(p.Dir) {
788 if ctxt.Compiler == "gccgo" && p.Goroot {
789 // gccgo has no sources for GOROOT packages.
793 // package was not found
794 return p, fmt.Errorf("cannot find package %q in:\n\t%s", p.ImportPath, p.Dir)
797 if mode&FindOnly != 0 {
800 if binaryOnly && (mode&AllowBinary) != 0 {
804 if ctxt.Compiler == "gccgo" && p.Goroot {
805 // gccgo has no sources for GOROOT packages.
809 dirs, err := ctxt.readDir(p.Dir)
815 badFiles := make(map[string]bool)
816 badFile := func(name string, err error) {
817 if badGoError == nil {
821 p.InvalidGoFiles = append(p.InvalidGoFiles, name)
822 badFiles[name] = true
826 var Sfiles []string // files with ".S"(capital S)/.sx(capital s equivalent for case insensitive filesystems)
827 var firstFile, firstCommentFile string
828 embedPos := make(map[string][]token.Position)
829 testEmbedPos := make(map[string][]token.Position)
830 xTestEmbedPos := make(map[string][]token.Position)
831 importPos := make(map[string][]token.Position)
832 testImportPos := make(map[string][]token.Position)
833 xTestImportPos := make(map[string][]token.Position)
834 allTags := make(map[string]bool)
835 fset := token.NewFileSet()
836 for _, d := range dirs {
840 if d.Mode()&fs.ModeSymlink != 0 {
841 if ctxt.isDir(ctxt.joinPath(p.Dir, d.Name())) {
842 // Symlinks to directories are not source files.
850 info, err := ctxt.matchFile(p.Dir, name, allTags, &p.BinaryOnly, fset)
856 if strings.HasPrefix(name, "_") || strings.HasPrefix(name, ".") {
857 // not due to build constraints - don't report
858 } else if ext == ".go" {
859 p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
860 } else if fileListForExt(p, ext) != nil {
861 p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, name)
865 data, filename := info.header, info.name
867 // Going to save the file. For non-Go files, can stop here.
872 // special case for cgo, handled at end
873 Sfiles = append(Sfiles, name)
876 if list := fileListForExt(p, ext); list != nil {
877 *list = append(*list, name)
882 if info.parseErr != nil {
883 badFile(name, info.parseErr)
884 // Fall through: we might still have a partial AST in info.parsed,
885 // and we want to list files with parse errors anyway.
889 if info.parsed != nil {
890 pkg = info.parsed.Name.Name
891 if pkg == "documentation" {
892 p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
897 isTest := strings.HasSuffix(name, "_test.go")
899 if isTest && strings.HasSuffix(pkg, "_test") && p.Name != pkg {
901 pkg = pkg[:len(pkg)-len("_test")]
907 } else if pkg != p.Name {
908 // TODO(#45999): The choice of p.Name is arbitrary based on file iteration
909 // order. Instead of resolving p.Name arbitrarily, we should clear out the
910 // existing name and mark the existing files as also invalid.
911 badFile(name, &MultiplePackageError{
913 Packages: []string{p.Name, pkg},
914 Files: []string{firstFile, name},
917 // Grab the first package comment as docs, provided it is not from a test file.
918 if info.parsed != nil && info.parsed.Doc != nil && p.Doc == "" && !isTest && !isXTest {
919 p.Doc = doc.Synopsis(info.parsed.Doc.Text())
922 if mode&ImportComment != 0 {
923 qcom, line := findImportComment(data)
925 com, err := strconv.Unquote(qcom)
927 badFile(name, fmt.Errorf("%s:%d: cannot parse import comment", filename, line))
928 } else if p.ImportComment == "" {
929 p.ImportComment = com
930 firstCommentFile = name
931 } else if p.ImportComment != com {
932 badFile(name, fmt.Errorf("found import comments %q (%s) and %q (%s) in %s", p.ImportComment, firstCommentFile, com, name, p.Dir))
937 // Record imports and information about cgo.
939 for _, imp := range info.imports {
942 badFile(name, fmt.Errorf("use of cgo in test %s not supported", filename))
947 if err := ctxt.saveCgo(filename, p, imp.doc); err != nil {
954 var fileList *[]string
955 var importMap, embedMap map[string][]token.Position
958 allTags["cgo"] = true
960 fileList = &p.CgoFiles
961 importMap = importPos
964 // Ignore imports and embeds from cgo files if cgo is disabled.
965 fileList = &p.IgnoredGoFiles
968 fileList = &p.XTestGoFiles
969 importMap = xTestImportPos
970 embedMap = xTestEmbedPos
972 fileList = &p.TestGoFiles
973 importMap = testImportPos
974 embedMap = testEmbedPos
976 fileList = &p.GoFiles
977 importMap = importPos
980 *fileList = append(*fileList, name)
981 if importMap != nil {
982 for _, imp := range info.imports {
983 importMap[imp.path] = append(importMap[imp.path], fset.Position(imp.pos))
987 for _, emb := range info.embeds {
988 embedMap[emb.pattern] = append(embedMap[emb.pattern], emb.pos)
993 for tag := range allTags {
994 p.AllTags = append(p.AllTags, tag)
996 sort.Strings(p.AllTags)
998 p.EmbedPatterns, p.EmbedPatternPos = cleanDecls(embedPos)
999 p.TestEmbedPatterns, p.TestEmbedPatternPos = cleanDecls(testEmbedPos)
1000 p.XTestEmbedPatterns, p.XTestEmbedPatternPos = cleanDecls(xTestEmbedPos)
1002 p.Imports, p.ImportPos = cleanDecls(importPos)
1003 p.TestImports, p.TestImportPos = cleanDecls(testImportPos)
1004 p.XTestImports, p.XTestImportPos = cleanDecls(xTestImportPos)
1006 // add the .S/.sx files only if we are using cgo
1007 // (which means gcc will compile them).
1008 // The standard assemblers expect .s files.
1009 if len(p.CgoFiles) > 0 {
1010 p.SFiles = append(p.SFiles, Sfiles...)
1011 sort.Strings(p.SFiles)
1013 p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, Sfiles...)
1014 sort.Strings(p.IgnoredOtherFiles)
1017 if badGoError != nil {
1018 return p, badGoError
1020 if len(p.GoFiles)+len(p.CgoFiles)+len(p.TestGoFiles)+len(p.XTestGoFiles) == 0 {
1021 return p, &NoGoError{p.Dir}
1026 func fileListForExt(p *Package, ext string) *[]string {
1030 case ".cc", ".cpp", ".cxx":
1034 case ".h", ".hh", ".hpp", ".hxx":
1036 case ".f", ".F", ".for", ".f90":
1038 case ".s", ".S", ".sx":
1043 return &p.SwigCXXFiles
1050 func uniq(list []string) []string {
1054 out := make([]string, len(list))
1058 for _, x := range out {
1059 if len(uniq) == 0 || uniq[len(uniq)-1] != x {
1060 uniq = append(uniq, x)
1066 var errNoModules = errors.New("not using modules")
1068 // importGo checks whether it can use the go command to find the directory for path.
1069 // If using the go command is not appropriate, importGo returns errNoModules.
1070 // Otherwise, importGo tries using the go command and reports whether that succeeded.
1071 // Using the go command lets build.Import and build.Context.Import find code
1072 // in Go modules. In the long term we want tools to use go/packages (currently golang.org/x/tools/go/packages),
1073 // which will also use the go command.
1074 // Invoking the go command here is not very efficient in that it computes information
1075 // about the requested package and all dependencies and then only reports about the requested package.
1076 // Then we reinvoke it for every dependency. But this is still better than not working at all.
1077 // See golang.org/issue/26504.
1078 func (ctxt *Context) importGo(p *Package, path, srcDir string, mode ImportMode) error {
1079 // To invoke the go command,
1080 // we must not being doing special things like AllowBinary or IgnoreVendor,
1081 // and all the file system callbacks must be nil (we're meant to use the local file system).
1082 if mode&AllowBinary != 0 || mode&IgnoreVendor != 0 ||
1083 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) {
1087 // If ctxt.GOROOT is not set, we don't know which go command to invoke,
1088 // and even if we did we might return packages in GOROOT that we wouldn't otherwise find
1089 // (because we don't know to search in 'go env GOROOT' otherwise).
1090 if ctxt.GOROOT == "" {
1094 // Predict whether module aware mode is enabled by checking the value of
1095 // GO111MODULE and looking for a go.mod file in the source directory or
1096 // one of its parents. Running 'go env GOMOD' in the source directory would
1097 // give a canonical answer, but we'd prefer not to execute another command.
1098 go111Module := os.Getenv("GO111MODULE")
1099 switch go111Module {
1102 default: // "", "on", "auto", anything else
1103 // Maybe use modules.
1107 var absSrcDir string
1108 if filepath.IsAbs(srcDir) {
1110 } else if ctxt.Dir != "" {
1111 return fmt.Errorf("go/build: Dir is non-empty, so relative srcDir is not allowed: %v", srcDir)
1113 // Find the absolute source directory. hasSubdir does not handle
1114 // relative paths (and can't because the callbacks don't support this).
1116 absSrcDir, err = filepath.Abs(srcDir)
1122 // If the source directory is in GOROOT, then the in-process code works fine
1123 // and we should keep using it. Moreover, the 'go list' approach below doesn't
1124 // take standard-library vendoring into account and will fail.
1125 if _, ok := ctxt.hasSubdir(filepath.Join(ctxt.GOROOT, "src"), absSrcDir); ok {
1130 // For efficiency, if path is a standard library package, let the usual lookup code handle it.
1131 if dir := ctxt.joinPath(ctxt.GOROOT, "src", path); ctxt.isDir(dir) {
1135 // If GO111MODULE=auto, look to see if there is a go.mod.
1136 // Since go1.13, it doesn't matter if we're inside GOPATH.
1137 if go111Module == "auto" {
1143 parent, err = os.Getwd()
1145 // A nonexistent working directory can't be in a module.
1149 parent, err = filepath.Abs(ctxt.Dir)
1151 // If the caller passed a bogus Dir explicitly, that's materially
1152 // different from not having modules enabled.
1157 if f, err := ctxt.openFile(ctxt.joinPath(parent, "go.mod")); err == nil {
1158 buf := make([]byte, 100)
1159 _, err := f.Read(buf)
1161 if err == nil || err == io.EOF {
1162 // go.mod exists and is readable (is a file, not a directory).
1166 d := filepath.Dir(parent)
1167 if len(d) >= len(parent) {
1168 return errNoModules // reached top of file system, no go.mod
1174 goCmd := filepath.Join(ctxt.GOROOT, "bin", "go")
1175 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)
1181 var stdout, stderr strings.Builder
1182 cmd.Stdout = &stdout
1183 cmd.Stderr = &stderr
1186 if ctxt.CgoEnabled {
1189 cmd.Env = append(os.Environ(),
1191 "GOARCH="+ctxt.GOARCH,
1192 "GOROOT="+ctxt.GOROOT,
1193 "GOPATH="+ctxt.GOPATH,
1197 // If possible, set PWD: if an error occurs and PWD includes a symlink, we
1198 // want the error to refer to Dir, not some other name for it.
1199 if abs, err := filepath.Abs(cmd.Dir); err == nil {
1200 cmd.Env = append(cmd.Env, "PWD="+abs)
1204 if err := cmd.Run(); err != nil {
1205 return fmt.Errorf("go/build: go list %s: %v\n%s\n", path, err, stderr.String())
1208 f := strings.SplitN(stdout.String(), "\n", 5)
1210 return fmt.Errorf("go/build: importGo %s: unexpected output:\n%s\n", path, stdout.String())
1213 errStr := strings.TrimSpace(f[4])
1214 if errStr != "" && dir == "" {
1215 // If 'go list' could not locate the package (dir is empty),
1216 // return the same error that 'go list' reported.
1217 return errors.New(errStr)
1220 // If 'go list' did locate the package, ignore the error.
1221 // It was probably related to loading source files, and we'll
1222 // encounter it ourselves shortly if the FindOnly flag isn't set.
1226 p.Goroot = f[3] == "true"
1230 func equal(x, y []string) bool {
1231 if len(x) != len(y) {
1234 for i, xi := range x {
1242 // hasGoFiles reports whether dir contains any files with names ending in .go.
1243 // For a vendor check we must exclude directories that contain no .go files.
1244 // Otherwise it is not possible to vendor just a/b/c and still import the
1245 // non-vendored a/b. See golang.org/issue/13832.
1246 func hasGoFiles(ctxt *Context, dir string) bool {
1247 ents, _ := ctxt.readDir(dir)
1248 for _, ent := range ents {
1249 if !ent.IsDir() && strings.HasSuffix(ent.Name(), ".go") {
1256 func findImportComment(data []byte) (s string, line int) {
1257 // expect keyword package
1258 word, data := parseWord(data)
1259 if string(word) != "package" {
1263 // expect package name
1264 _, data = parseWord(data)
1266 // now ready for import comment, a // or /* */ comment
1267 // beginning and ending on the current line.
1268 for len(data) > 0 && (data[0] == ' ' || data[0] == '\t' || data[0] == '\r') {
1274 case bytes.HasPrefix(data, slashSlash):
1275 comment, _, _ = bytes.Cut(data[2:], newline)
1276 case bytes.HasPrefix(data, slashStar):
1278 comment, _, ok = bytes.Cut(data[2:], starSlash)
1280 // malformed comment
1283 if bytes.Contains(comment, newline) {
1287 comment = bytes.TrimSpace(comment)
1289 // split comment into `import`, `"pkg"`
1290 word, arg := parseWord(comment)
1291 if string(word) != "import" {
1295 line = 1 + bytes.Count(data[:cap(data)-cap(arg)], newline)
1296 return strings.TrimSpace(string(arg)), line
1300 slashSlash = []byte("//")
1301 slashStar = []byte("/*")
1302 starSlash = []byte("*/")
1303 newline = []byte("\n")
1306 // skipSpaceOrComment returns data with any leading spaces or comments removed.
1307 func skipSpaceOrComment(data []byte) []byte {
1310 case ' ', '\t', '\r', '\n':
1314 if bytes.HasPrefix(data, slashSlash) {
1315 i := bytes.Index(data, newline)
1322 if bytes.HasPrefix(data, slashStar) {
1324 i := bytes.Index(data, starSlash)
1337 // parseWord skips any leading spaces or comments in data
1338 // and then parses the beginning of data as an identifier or keyword,
1339 // returning that word and what remains after the word.
1340 func parseWord(data []byte) (word, rest []byte) {
1341 data = skipSpaceOrComment(data)
1343 // Parse past leading word characters.
1346 r, size := utf8.DecodeRune(rest)
1347 if unicode.IsLetter(r) || '0' <= r && r <= '9' || r == '_' {
1354 word = data[:len(data)-len(rest)]
1362 // MatchFile reports whether the file with the given name in the given directory
1363 // matches the context and would be included in a Package created by ImportDir
1364 // of that directory.
1366 // MatchFile considers the name of the file and may use ctxt.OpenFile to
1367 // read some or all of the file's content.
1368 func (ctxt *Context) MatchFile(dir, name string) (match bool, err error) {
1369 info, err := ctxt.matchFile(dir, name, nil, nil, nil)
1370 return info != nil, err
1373 var dummyPkg Package
1375 // fileInfo records information learned about a file included in a build.
1376 type fileInfo struct {
1377 name string // full name including dir
1382 imports []fileImport
1387 type fileImport struct {
1390 doc *ast.CommentGroup
1393 type fileEmbed struct {
1398 // matchFile determines whether the file with the given name in the given directory
1399 // should be included in the package being constructed.
1400 // If the file should be included, matchFile returns a non-nil *fileInfo (and a nil error).
1401 // Non-nil errors are reserved for unexpected problems.
1403 // If name denotes a Go program, matchFile reads until the end of the
1404 // imports and returns that section of the file in the fileInfo's header field,
1405 // even though it only considers text until the first non-comment
1406 // for +build lines.
1408 // If allTags is non-nil, matchFile records any encountered build tag
1409 // by setting allTags[tag] = true.
1410 func (ctxt *Context) matchFile(dir, name string, allTags map[string]bool, binaryOnly *bool, fset *token.FileSet) (*fileInfo, error) {
1411 if strings.HasPrefix(name, "_") ||
1412 strings.HasPrefix(name, ".") {
1416 i := strings.LastIndex(name, ".")
1422 if !ctxt.goodOSArchFile(name, allTags) && !ctxt.UseAllFiles {
1426 if ext != ".go" && fileListForExt(&dummyPkg, ext) == nil {
1431 info := &fileInfo{name: ctxt.joinPath(dir, name), fset: fset}
1433 // binary, no reading
1437 f, err := ctxt.openFile(info.name)
1442 if strings.HasSuffix(name, ".go") {
1443 err = readGoInfo(f, info)
1444 if strings.HasSuffix(name, "_test.go") {
1445 binaryOnly = nil // ignore //go:binary-only-package comments in _test.go files
1448 binaryOnly = nil // ignore //go:binary-only-package comments in non-Go sources
1449 info.header, err = readComments(f)
1453 return nil, fmt.Errorf("read %s: %v", info.name, err)
1456 // Look for +build comments to accept or reject the file.
1457 ok, sawBinaryOnly, err := ctxt.shouldBuild(info.header, allTags)
1459 return nil, fmt.Errorf("%s: %v", name, err)
1461 if !ok && !ctxt.UseAllFiles {
1465 if binaryOnly != nil && sawBinaryOnly {
1472 func cleanDecls(m map[string][]token.Position) ([]string, map[string][]token.Position) {
1473 all := make([]string, 0, len(m))
1474 for path := range m {
1475 all = append(all, path)
1481 // Import is shorthand for Default.Import.
1482 func Import(path, srcDir string, mode ImportMode) (*Package, error) {
1483 return Default.Import(path, srcDir, mode)
1486 // ImportDir is shorthand for Default.ImportDir.
1487 func ImportDir(dir string, mode ImportMode) (*Package, error) {
1488 return Default.ImportDir(dir, mode)
1492 bSlashSlash = []byte(slashSlash)
1493 bStarSlash = []byte(starSlash)
1494 bSlashStar = []byte(slashStar)
1495 bPlusBuild = []byte("+build")
1497 goBuildComment = []byte("//go:build")
1499 errGoBuildWithoutBuild = errors.New("//go:build comment without // +build comment")
1500 errMultipleGoBuild = errors.New("multiple //go:build comments")
1503 func isGoBuildComment(line []byte) bool {
1504 if !bytes.HasPrefix(line, goBuildComment) {
1507 line = bytes.TrimSpace(line)
1508 rest := line[len(goBuildComment):]
1509 return len(rest) == 0 || len(bytes.TrimSpace(rest)) < len(rest)
1512 // Special comment denoting a binary-only package.
1513 // See https://golang.org/design/2775-binary-only-packages
1514 // for more about the design of binary-only packages.
1515 var binaryOnlyComment = []byte("//go:binary-only-package")
1517 // shouldBuild reports whether it is okay to use this file,
1518 // The rule is that in the file's leading run of // comments
1519 // and blank lines, which must be followed by a blank line
1520 // (to avoid including a Go package clause doc comment),
1521 // lines beginning with '// +build' are taken as build directives.
1523 // The file is accepted only if each such line lists something
1524 // matching the file. For example:
1526 // // +build windows linux
1528 // marks the file as applicable only on Windows and Linux.
1530 // For each build tag it consults, shouldBuild sets allTags[tag] = true.
1532 // shouldBuild reports whether the file should be built
1533 // and whether a //go:binary-only-package comment was found.
1534 func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool) (shouldBuild, binaryOnly bool, err error) {
1535 // Identify leading run of // comments and blank lines,
1536 // which must be followed by a blank line.
1537 // Also identify any //go:build comments.
1538 content, goBuild, sawBinaryOnly, err := parseFileHeader(content)
1540 return false, false, err
1543 // If //go:build line is present, it controls.
1544 // Otherwise fall back to +build processing.
1546 case goBuild != nil:
1547 x, err := constraint.Parse(string(goBuild))
1549 return false, false, fmt.Errorf("parsing //go:build line: %v", err)
1551 shouldBuild = ctxt.eval(x, allTags)
1558 if i := bytes.IndexByte(line, '\n'); i >= 0 {
1559 line, p = line[:i], p[i+1:]
1563 line = bytes.TrimSpace(line)
1564 if !bytes.HasPrefix(line, bSlashSlash) || !bytes.Contains(line, bPlusBuild) {
1567 text := string(line)
1568 if !constraint.IsPlusBuild(text) {
1571 if x, err := constraint.Parse(text); err == nil {
1572 if !ctxt.eval(x, allTags) {
1579 return shouldBuild, sawBinaryOnly, nil
1582 func parseFileHeader(content []byte) (trimmed, goBuild []byte, sawBinaryOnly bool, err error) {
1585 ended := false // found non-blank, non-// line, so stopped accepting // +build lines
1586 inSlashStar := false // in /* */ comment
1591 if i := bytes.IndexByte(line, '\n'); i >= 0 {
1592 line, p = line[:i], p[i+1:]
1596 line = bytes.TrimSpace(line)
1597 if len(line) == 0 && !ended { // Blank line
1598 // Remember position of most recent blank line.
1599 // When we find the first non-blank, non-// line,
1600 // this "end" position marks the latest file position
1601 // where a // +build line can appear.
1602 // (It must appear _before_ a blank line before the non-blank, non-// line.
1603 // Yes, that's confusing, which is part of why we moved to //go:build lines.)
1604 // Note that ended==false here means that inSlashStar==false,
1605 // since seeing a /* would have set ended==true.
1606 end = len(content) - len(p)
1609 if !bytes.HasPrefix(line, slashSlash) { // Not comment line
1613 if !inSlashStar && isGoBuildComment(line) {
1615 return nil, nil, false, errMultipleGoBuild
1619 if !inSlashStar && bytes.Equal(line, binaryOnlyComment) {
1620 sawBinaryOnly = true
1626 if i := bytes.Index(line, starSlash); i >= 0 {
1628 line = bytes.TrimSpace(line[i+len(starSlash):])
1633 if bytes.HasPrefix(line, bSlashSlash) {
1636 if bytes.HasPrefix(line, bSlashStar) {
1638 line = bytes.TrimSpace(line[len(bSlashStar):])
1641 // Found non-comment text.
1646 return content[:end], goBuild, sawBinaryOnly, nil
1649 // saveCgo saves the information from the #cgo lines in the import "C" comment.
1650 // These lines set CFLAGS, CPPFLAGS, CXXFLAGS and LDFLAGS and pkg-config directives
1651 // that affect the way cgo's C code is built.
1652 func (ctxt *Context) saveCgo(filename string, di *Package, cg *ast.CommentGroup) error {
1654 for _, line := range strings.Split(text, "\n") {
1658 // #cgo [GOOS/GOARCH...] LDFLAGS: stuff
1660 line = strings.TrimSpace(line)
1661 if len(line) < 5 || line[:4] != "#cgo" || (line[4] != ' ' && line[4] != '\t') {
1666 line, argstr, ok := strings.Cut(strings.TrimSpace(line[4:]), ":")
1668 return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
1671 // Parse GOOS/GOARCH stuff.
1672 f := strings.Fields(line)
1674 return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
1677 cond, verb := f[:len(f)-1], f[len(f)-1]
1680 for _, c := range cond {
1681 if ctxt.matchAuto(c, nil) {
1691 args, err := splitQuoted(argstr)
1693 return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
1695 for i, arg := range args {
1696 if arg, ok = expandSrcDir(arg, di.Dir); !ok {
1697 return fmt.Errorf("%s: malformed #cgo argument: %s", filename, arg)
1703 case "CFLAGS", "CPPFLAGS", "CXXFLAGS", "FFLAGS", "LDFLAGS":
1704 // Change relative paths to absolute.
1705 ctxt.makePathsAbsolute(args, di.Dir)
1710 di.CgoCFLAGS = append(di.CgoCFLAGS, args...)
1712 di.CgoCPPFLAGS = append(di.CgoCPPFLAGS, args...)
1714 di.CgoCXXFLAGS = append(di.CgoCXXFLAGS, args...)
1716 di.CgoFFLAGS = append(di.CgoFFLAGS, args...)
1718 di.CgoLDFLAGS = append(di.CgoLDFLAGS, args...)
1720 di.CgoPkgConfig = append(di.CgoPkgConfig, args...)
1722 return fmt.Errorf("%s: invalid #cgo verb: %s", filename, orig)
1728 // expandSrcDir expands any occurrence of ${SRCDIR}, making sure
1729 // the result is safe for the shell.
1730 func expandSrcDir(str string, srcdir string) (string, bool) {
1731 // "\" delimited paths cause safeCgoName to fail
1732 // so convert native paths with a different delimiter
1733 // to "/" before starting (eg: on windows).
1734 srcdir = filepath.ToSlash(srcdir)
1736 chunks := strings.Split(str, "${SRCDIR}")
1737 if len(chunks) < 2 {
1738 return str, safeCgoName(str)
1741 for _, chunk := range chunks {
1742 ok = ok && (chunk == "" || safeCgoName(chunk))
1744 ok = ok && (srcdir == "" || safeCgoName(srcdir))
1745 res := strings.Join(chunks, srcdir)
1746 return res, ok && res != ""
1749 // makePathsAbsolute looks for compiler options that take paths and
1750 // makes them absolute. We do this because through the 1.8 release we
1751 // ran the compiler in the package directory, so any relative -I or -L
1752 // options would be relative to that directory. In 1.9 we changed to
1753 // running the compiler in the build directory, to get consistent
1754 // build results (issue #19964). To keep builds working, we change any
1755 // relative -I or -L options to be absolute.
1757 // Using filepath.IsAbs and filepath.Join here means the results will be
1758 // different on different systems, but that's OK: -I and -L options are
1759 // inherently system-dependent.
1760 func (ctxt *Context) makePathsAbsolute(args []string, srcDir string) {
1762 for i, arg := range args {
1764 if !filepath.IsAbs(arg) {
1765 args[i] = filepath.Join(srcDir, arg)
1768 } else if strings.HasPrefix(arg, "-I") || strings.HasPrefix(arg, "-L") {
1772 if !filepath.IsAbs(arg[2:]) {
1773 args[i] = arg[:2] + filepath.Join(srcDir, arg[2:])
1780 // NOTE: $ is not safe for the shell, but it is allowed here because of linker options like -Wl,$ORIGIN.
1781 // We never pass these arguments to a shell (just to programs we construct argv for), so this should be okay.
1782 // See golang.org/issue/6038.
1783 // The @ is for OS X. See golang.org/issue/13720.
1784 // The % is for Jenkins. See golang.org/issue/16959.
1785 // The ! is because module paths may use them. See golang.org/issue/26716.
1786 // The ~ and ^ are for sr.ht. See golang.org/issue/32260.
1787 const safeString = "+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:$@%! ~^"
1789 func safeCgoName(s string) bool {
1793 for i := 0; i < len(s); i++ {
1794 if c := s[i]; c < utf8.RuneSelf && strings.IndexByte(safeString, c) < 0 {
1801 // splitQuoted splits the string s around each instance of one or more consecutive
1802 // white space characters while taking into account quotes and escaping, and
1803 // returns an array of substrings of s or an empty list if s contains only white space.
1804 // Single quotes and double quotes are recognized to prevent splitting within the
1805 // quoted region, and are removed from the resulting substrings. If a quote in s
1806 // isn't closed err will be set and r will have the unclosed argument as the
1807 // last element. The backslash is used for escaping.
1809 // For example, the following string:
1811 // a b:"c d" 'e''f' "g\""
1813 // Would be parsed as:
1815 // []string{"a", "b:c d", "ef", `g"`}
1817 func splitQuoted(s string) (r []string, err error) {
1819 arg := make([]rune, len(s))
1824 for _, rune := range s {
1831 case quote != '\x00':
1836 case rune == '"' || rune == '\'':
1840 case unicode.IsSpace(rune):
1841 if quoted || i > 0 {
1843 args = append(args, string(arg[:i]))
1851 if quoted || i > 0 {
1852 args = append(args, string(arg[:i]))
1855 err = errors.New("unclosed quote")
1857 err = errors.New("unfinished escaping")
1862 // matchAuto interprets text as either a +build or //go:build expression (whichever works),
1863 // reporting whether the expression matches the build context.
1865 // matchAuto is only used for testing of tag evaluation
1866 // and in #cgo lines, which accept either syntax.
1867 func (ctxt *Context) matchAuto(text string, allTags map[string]bool) bool {
1868 if strings.ContainsAny(text, "&|()") {
1869 text = "//go:build " + text
1871 text = "// +build " + text
1873 x, err := constraint.Parse(text)
1877 return ctxt.eval(x, allTags)
1880 func (ctxt *Context) eval(x constraint.Expr, allTags map[string]bool) bool {
1881 return x.Eval(func(tag string) bool { return ctxt.matchTag(tag, allTags) })
1884 // matchTag reports whether the name is one of:
1886 // cgo (if cgo is enabled)
1890 // linux (if GOOS = android)
1891 // solaris (if GOOS = illumos)
1892 // tag (if tag is listed in ctxt.BuildTags or ctxt.ReleaseTags)
1894 // It records all consulted tags in allTags.
1895 func (ctxt *Context) matchTag(name string, allTags map[string]bool) bool {
1897 allTags[name] = true
1901 if ctxt.CgoEnabled && name == "cgo" {
1904 if name == ctxt.GOOS || name == ctxt.GOARCH || name == ctxt.Compiler {
1907 if ctxt.GOOS == "android" && name == "linux" {
1910 if ctxt.GOOS == "illumos" && name == "solaris" {
1913 if ctxt.GOOS == "ios" && name == "darwin" {
1916 if name == "unix" && unixOS[ctxt.GOOS] {
1921 for _, tag := range ctxt.BuildTags {
1926 for _, tag := range ctxt.ToolTags {
1931 for _, tag := range ctxt.ReleaseTags {
1940 // goodOSArchFile returns false if the name contains a $GOOS or $GOARCH
1941 // suffix which does not match the current system.
1942 // The recognized name formats are:
1946 // name_$(GOOS)_$(GOARCH).*
1947 // name_$(GOOS)_test.*
1948 // name_$(GOARCH)_test.*
1949 // name_$(GOOS)_$(GOARCH)_test.*
1952 // if GOOS=android, then files with GOOS=linux are also matched.
1953 // if GOOS=illumos, then files with GOOS=solaris are also matched.
1954 // if GOOS=ios, then files with GOOS=darwin are also matched.
1955 func (ctxt *Context) goodOSArchFile(name string, allTags map[string]bool) bool {
1956 name, _, _ = strings.Cut(name, ".")
1958 // Before Go 1.4, a file called "linux.go" would be equivalent to having a
1959 // build tag "linux" in that file. For Go 1.4 and beyond, we require this
1960 // auto-tagging to apply only to files with a non-empty prefix, so
1961 // "foo_linux.go" is tagged but "linux.go" is not. This allows new operating
1962 // systems, such as android, to arrive without breaking existing code with
1963 // innocuous source code in "android.go". The easiest fix: cut everything
1964 // in the name before the initial _.
1965 i := strings.Index(name, "_")
1969 name = name[i:] // ignore everything before first _
1971 l := strings.Split(name, "_")
1972 if n := len(l); n > 0 && l[n-1] == "test" {
1976 if n >= 2 && knownOS[l[n-2]] && knownArch[l[n-1]] {
1977 return ctxt.matchTag(l[n-1], allTags) && ctxt.matchTag(l[n-2], allTags)
1979 if n >= 1 && (knownOS[l[n-1]] || knownArch[l[n-1]]) {
1980 return ctxt.matchTag(l[n-1], allTags)
1985 // ToolDir is the directory containing build tools.
1986 var ToolDir = getToolDir()
1988 // IsLocalImport reports whether the import path is
1989 // a local import path, like ".", "..", "./foo", or "../foo".
1990 func IsLocalImport(path string) bool {
1991 return path == "." || path == ".." ||
1992 strings.HasPrefix(path, "./") || strings.HasPrefix(path, "../")
1995 // ArchChar returns "?" and an error.
1996 // In earlier versions of Go, the returned string was used to derive
1997 // the compiler and linker tool names, the default object file suffix,
1998 // and the default linker output name. As of Go 1.5, those strings
1999 // no longer vary by architecture; they are compile, link, .o, and a.out, respectively.
2000 func ArchChar(goarch string) (string, error) {
2001 return "?", errors.New("architecture letter no longer used")