diff options
Diffstat (limited to 'src/cmd/go/internal/load/pkg.go')
| -rw-r--r-- | src/cmd/go/internal/load/pkg.go | 2594 |
1 files changed, 2594 insertions, 0 deletions
diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go new file mode 100644 index 0000000..61fde89 --- /dev/null +++ b/src/cmd/go/internal/load/pkg.go @@ -0,0 +1,2594 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package load loads packages. +package load + +import ( + "bytes" + "context" + "encoding/json" + "errors" + "fmt" + "go/build" + "go/scanner" + "go/token" + "io/fs" + "os" + "path" + pathpkg "path" + "path/filepath" + "runtime" + "sort" + "strconv" + "strings" + "unicode" + "unicode/utf8" + + "cmd/go/internal/base" + "cmd/go/internal/cfg" + "cmd/go/internal/fsys" + "cmd/go/internal/modinfo" + "cmd/go/internal/modload" + "cmd/go/internal/par" + "cmd/go/internal/search" + "cmd/go/internal/str" + "cmd/go/internal/trace" + "cmd/internal/sys" + + "golang.org/x/mod/module" +) + +var IgnoreImports bool // control whether we ignore imports in packages + +// A Package describes a single package found in a directory. +type Package struct { + PackagePublic // visible in 'go list' + Internal PackageInternal // for use inside go command only +} + +type PackagePublic struct { + // Note: These fields are part of the go command's public API. + // See list.go. It is okay to add fields, but not to change or + // remove existing ones. Keep in sync with list.go + Dir string `json:",omitempty"` // directory containing package sources + ImportPath string `json:",omitempty"` // import path of package in dir + ImportComment string `json:",omitempty"` // path in import comment on package statement + Name string `json:",omitempty"` // package name + Doc string `json:",omitempty"` // package documentation string + Target string `json:",omitempty"` // installed target for this package (may be executable) + Shlib string `json:",omitempty"` // the shared library that contains this package (only set when -linkshared) + Root string `json:",omitempty"` // Go root, Go path dir, or module root dir containing this package + ConflictDir string `json:",omitempty"` // Dir is hidden by this other directory + ForTest string `json:",omitempty"` // package is only for use in named test + Export string `json:",omitempty"` // file containing export data (set by go list -export) + BuildID string `json:",omitempty"` // build ID of the compiled package (set by go list -export) + Module *modinfo.ModulePublic `json:",omitempty"` // info about package's module, if any + Match []string `json:",omitempty"` // command-line patterns matching this package + Goroot bool `json:",omitempty"` // is this package found in the Go root? + Standard bool `json:",omitempty"` // is this package part of the standard Go library? + DepOnly bool `json:",omitempty"` // package is only as a dependency, not explicitly listed + BinaryOnly bool `json:",omitempty"` // package cannot be recompiled + Incomplete bool `json:",omitempty"` // was there an error loading this package or dependencies? + + // Stale and StaleReason remain here *only* for the list command. + // They are only initialized in preparation for list execution. + // The regular build determines staleness on the fly during action execution. + Stale bool `json:",omitempty"` // would 'go install' do anything for this package? + StaleReason string `json:",omitempty"` // why is Stale true? + + // Source files + // If you add to this list you MUST add to p.AllFiles (below) too. + // Otherwise file name security lists will not apply to any new additions. + GoFiles []string `json:",omitempty"` // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles) + CgoFiles []string `json:",omitempty"` // .go source files that import "C" + CompiledGoFiles []string `json:",omitempty"` // .go output from running cgo on CgoFiles + IgnoredGoFiles []string `json:",omitempty"` // .go source files ignored due to build constraints + IgnoredOtherFiles []string `json:",omitempty"` // non-.go source files ignored due to build constraints + CFiles []string `json:",omitempty"` // .c source files + CXXFiles []string `json:",omitempty"` // .cc, .cpp and .cxx source files + MFiles []string `json:",omitempty"` // .m source files + HFiles []string `json:",omitempty"` // .h, .hh, .hpp and .hxx source files + FFiles []string `json:",omitempty"` // .f, .F, .for and .f90 Fortran source files + SFiles []string `json:",omitempty"` // .s source files + SwigFiles []string `json:",omitempty"` // .swig files + SwigCXXFiles []string `json:",omitempty"` // .swigcxx files + SysoFiles []string `json:",omitempty"` // .syso system object files added to package + + // Embedded files + EmbedPatterns []string `json:",omitempty"` // //go:embed patterns + EmbedFiles []string `json:",omitempty"` // files matched by EmbedPatterns + + // Cgo directives + CgoCFLAGS []string `json:",omitempty"` // cgo: flags for C compiler + CgoCPPFLAGS []string `json:",omitempty"` // cgo: flags for C preprocessor + CgoCXXFLAGS []string `json:",omitempty"` // cgo: flags for C++ compiler + CgoFFLAGS []string `json:",omitempty"` // cgo: flags for Fortran compiler + CgoLDFLAGS []string `json:",omitempty"` // cgo: flags for linker + CgoPkgConfig []string `json:",omitempty"` // cgo: pkg-config names + + // Dependency information + Imports []string `json:",omitempty"` // import paths used by this package + ImportMap map[string]string `json:",omitempty"` // map from source import to ImportPath (identity entries omitted) + Deps []string `json:",omitempty"` // all (recursively) imported dependencies + + // Error information + // Incomplete is above, packed into the other bools + Error *PackageError `json:",omitempty"` // error loading this package (not dependencies) + DepsErrors []*PackageError `json:",omitempty"` // errors loading dependencies + + // Test information + // If you add to this list you MUST add to p.AllFiles (below) too. + // Otherwise file name security lists will not apply to any new additions. + TestGoFiles []string `json:",omitempty"` // _test.go files in package + TestImports []string `json:",omitempty"` // imports from TestGoFiles + TestEmbedPatterns []string `json:",omitempty"` // //go:embed patterns + TestEmbedFiles []string `json:",omitempty"` // files matched by TestEmbedPatterns + XTestGoFiles []string `json:",omitempty"` // _test.go files outside package + XTestImports []string `json:",omitempty"` // imports from XTestGoFiles + XTestEmbedPatterns []string `json:",omitempty"` // //go:embed patterns + XTestEmbedFiles []string `json:",omitempty"` // files matched by XTestEmbedPatterns +} + +// AllFiles returns the names of all the files considered for the package. +// This is used for sanity and security checks, so we include all files, +// even IgnoredGoFiles, because some subcommands consider them. +// The go/build package filtered others out (like foo_wrongGOARCH.s) +// and that's OK. +func (p *Package) AllFiles() []string { + files := str.StringList( + p.GoFiles, + p.CgoFiles, + // no p.CompiledGoFiles, because they are from GoFiles or generated by us + p.IgnoredGoFiles, + p.IgnoredOtherFiles, + p.CFiles, + p.CXXFiles, + p.MFiles, + p.HFiles, + p.FFiles, + p.SFiles, + p.SwigFiles, + p.SwigCXXFiles, + p.SysoFiles, + p.TestGoFiles, + p.XTestGoFiles, + ) + + // EmbedFiles may overlap with the other files. + // Dedup, but delay building the map as long as possible. + // Only files in the current directory (no slash in name) + // need to be checked against the files variable above. + var have map[string]bool + for _, file := range p.EmbedFiles { + if !strings.Contains(file, "/") { + if have == nil { + have = make(map[string]bool) + for _, file := range files { + have[file] = true + } + } + if have[file] { + continue + } + } + files = append(files, file) + } + return files +} + +// Desc returns the package "description", for use in b.showOutput. +func (p *Package) Desc() string { + if p.ForTest != "" { + return p.ImportPath + " [" + p.ForTest + ".test]" + } + return p.ImportPath +} + +type PackageInternal struct { + // Unexported fields are not part of the public API. + Build *build.Package + Imports []*Package // this package's direct imports + CompiledImports []string // additional Imports necessary when using CompiledGoFiles (all from standard library) + RawImports []string // this package's original imports as they appear in the text of the program + ForceLibrary bool // this package is a library (even if named "main") + CmdlineFiles bool // package built from files listed on command line + CmdlinePkg bool // package listed on command line + CmdlinePkgLiteral bool // package listed as literal on command line (not via wildcard) + Local bool // imported via local path (./ or ../) + LocalPrefix string // interpret ./ and ../ imports relative to this prefix + ExeName string // desired name for temporary executable + CoverMode string // preprocess Go source files with the coverage tool in this mode + CoverVars map[string]*CoverVar // variables created by coverage analysis + OmitDebug bool // tell linker not to write debug information + GobinSubdir bool // install target would be subdir of GOBIN + BuildInfo string // add this info to package main + TestmainGo *[]byte // content for _testmain.go + Embed map[string][]string // //go:embed comment mapping + + Asmflags []string // -asmflags for this package + Gcflags []string // -gcflags for this package + Ldflags []string // -ldflags for this package + Gccgoflags []string // -gccgoflags for this package +} + +// A NoGoError indicates that no Go files for the package were applicable to the +// build for that package. +// +// That may be because there were no files whatsoever, or because all files were +// excluded, or because all non-excluded files were test sources. +type NoGoError struct { + Package *Package +} + +func (e *NoGoError) Error() string { + if len(e.Package.IgnoredGoFiles) > 0 { + // Go files exist, but they were ignored due to build constraints. + return "build constraints exclude all Go files in " + e.Package.Dir + } + if len(e.Package.TestGoFiles)+len(e.Package.XTestGoFiles) > 0 { + // Test Go files exist, but we're not interested in them. + // The double-negative is unfortunate but we want e.Package.Dir + // to appear at the end of error message. + return "no non-test Go files in " + e.Package.Dir + } + return "no Go files in " + e.Package.Dir +} + +// setLoadPackageDataError presents an error found when loading package data +// as a *PackageError. It has special cases for some common errors to improve +// messages shown to users and reduce redundancy. +// +// setLoadPackageDataError returns true if it's safe to load information about +// imported packages, for example, if there was a parse error loading imports +// in one file, but other files are okay. +func (p *Package) setLoadPackageDataError(err error, path string, stk *ImportStack, importPos []token.Position) { + matchErr, isMatchErr := err.(*search.MatchError) + if isMatchErr && matchErr.Match.Pattern() == path { + if matchErr.Match.IsLiteral() { + // The error has a pattern has a pattern similar to the import path. + // It may be slightly different (./foo matching example.com/foo), + // but close enough to seem redundant. + // Unwrap the error so we don't show the pattern. + err = matchErr.Err + } + } + + // Replace (possibly wrapped) *build.NoGoError with *load.NoGoError. + // The latter is more specific about the cause. + var nogoErr *build.NoGoError + if errors.As(err, &nogoErr) { + if p.Dir == "" && nogoErr.Dir != "" { + p.Dir = nogoErr.Dir + } + err = &NoGoError{Package: p} + } + + // Take only the first error from a scanner.ErrorList. PackageError only + // has room for one position, so we report the first error with a position + // instead of all of the errors without a position. + var pos string + var isScanErr bool + if scanErr, ok := err.(scanner.ErrorList); ok && len(scanErr) > 0 { + isScanErr = true // For stack push/pop below. + + scanPos := scanErr[0].Pos + scanPos.Filename = base.ShortPath(scanPos.Filename) + pos = scanPos.String() + err = errors.New(scanErr[0].Msg) + } + + // Report the error on the importing package if the problem is with the import declaration + // for example, if the package doesn't exist or if the import path is malformed. + // On the other hand, don't include a position if the problem is with the imported package, + // for example there are no Go files (NoGoError), or there's a problem in the imported + // package's source files themselves (scanner errors). + // + // TODO(matloob): Perhaps make each of those the errors in the first group + // (including modload.ImportMissingError, ImportMissingSumError, and the + // corresponding "cannot find package %q in any of" GOPATH-mode error + // produced in build.(*Context).Import; modload.AmbiguousImportError, + // and modload.PackageNotInModuleError; and the malformed module path errors + // produced in golang.org/x/mod/module.CheckMod) implement an interface + // to make it easier to check for them? That would save us from having to + // move the modload errors into this package to avoid a package import cycle, + // and from having to export an error type for the errors produced in build. + if !isMatchErr && (nogoErr != nil || isScanErr) { + stk.Push(path) + defer stk.Pop() + } + + p.Error = &PackageError{ + ImportStack: stk.Copy(), + Pos: pos, + Err: err, + } + + if path != stk.Top() { + p.Error.setPos(importPos) + } +} + +// Resolve returns the resolved version of imports, +// which should be p.TestImports or p.XTestImports, NOT p.Imports. +// The imports in p.TestImports and p.XTestImports are not recursively +// loaded during the initial load of p, so they list the imports found in +// the source file, but most processing should be over the vendor-resolved +// import paths. We do this resolution lazily both to avoid file system work +// and because the eventual real load of the test imports (during 'go test') +// can produce better error messages if it starts with the original paths. +// The initial load of p loads all the non-test imports and rewrites +// the vendored paths, so nothing should ever call p.vendored(p.Imports). +func (p *Package) Resolve(imports []string) []string { + if len(imports) > 0 && len(p.Imports) > 0 && &imports[0] == &p.Imports[0] { + panic("internal error: p.Resolve(p.Imports) called") + } + seen := make(map[string]bool) + var all []string + for _, path := range imports { + path = ResolveImportPath(p, path) + if !seen[path] { + seen[path] = true + all = append(all, path) + } + } + sort.Strings(all) + return all +} + +// CoverVar holds the name of the generated coverage variables targeting the named file. +type CoverVar struct { + File string // local file name + Var string // name of count struct +} + +func (p *Package) copyBuild(pp *build.Package) { + p.Internal.Build = pp + + if pp.PkgTargetRoot != "" && cfg.BuildPkgdir != "" { + old := pp.PkgTargetRoot + pp.PkgRoot = cfg.BuildPkgdir + pp.PkgTargetRoot = cfg.BuildPkgdir + pp.PkgObj = filepath.Join(cfg.BuildPkgdir, strings.TrimPrefix(pp.PkgObj, old)) + } + + p.Dir = pp.Dir + p.ImportPath = pp.ImportPath + p.ImportComment = pp.ImportComment + p.Name = pp.Name + p.Doc = pp.Doc + p.Root = pp.Root + p.ConflictDir = pp.ConflictDir + p.BinaryOnly = pp.BinaryOnly + + // TODO? Target + p.Goroot = pp.Goroot + p.Standard = p.Goroot && p.ImportPath != "" && search.IsStandardImportPath(p.ImportPath) + p.GoFiles = pp.GoFiles + p.CgoFiles = pp.CgoFiles + p.IgnoredGoFiles = pp.IgnoredGoFiles + p.IgnoredOtherFiles = pp.IgnoredOtherFiles + p.CFiles = pp.CFiles + p.CXXFiles = pp.CXXFiles + p.MFiles = pp.MFiles + p.HFiles = pp.HFiles + p.FFiles = pp.FFiles + p.SFiles = pp.SFiles + p.SwigFiles = pp.SwigFiles + p.SwigCXXFiles = pp.SwigCXXFiles + p.SysoFiles = pp.SysoFiles + p.CgoCFLAGS = pp.CgoCFLAGS + p.CgoCPPFLAGS = pp.CgoCPPFLAGS + p.CgoCXXFLAGS = pp.CgoCXXFLAGS + p.CgoFFLAGS = pp.CgoFFLAGS + p.CgoLDFLAGS = pp.CgoLDFLAGS + p.CgoPkgConfig = pp.CgoPkgConfig + // We modify p.Imports in place, so make copy now. + p.Imports = make([]string, len(pp.Imports)) + copy(p.Imports, pp.Imports) + p.Internal.RawImports = pp.Imports + p.TestGoFiles = pp.TestGoFiles + p.TestImports = pp.TestImports + p.XTestGoFiles = pp.XTestGoFiles + p.XTestImports = pp.XTestImports + if IgnoreImports { + p.Imports = nil + p.Internal.RawImports = nil + p.TestImports = nil + p.XTestImports = nil + } + p.EmbedPatterns = pp.EmbedPatterns + p.TestEmbedPatterns = pp.TestEmbedPatterns + p.XTestEmbedPatterns = pp.XTestEmbedPatterns +} + +// A PackageError describes an error loading information about a package. +type PackageError struct { + ImportStack []string // shortest path from package named on command line to this one + Pos string // position of error + Err error // the error itself + IsImportCycle bool // the error is an import cycle + Hard bool // whether the error is soft or hard; soft errors are ignored in some places + alwaysPrintStack bool // whether to always print the ImportStack +} + +func (p *PackageError) Error() string { + // TODO(#43696): decide when to print the stack or the position based on + // the error type and whether the package is in the main module. + // Document the rationale. + if p.Pos != "" && (len(p.ImportStack) == 0 || !p.alwaysPrintStack) { + // Omit import stack. The full path to the file where the error + // is the most important thing. + return p.Pos + ": " + p.Err.Error() + } + + // If the error is an ImportPathError, and the last path on the stack appears + // in the error message, omit that path from the stack to avoid repetition. + // If an ImportPathError wraps another ImportPathError that matches the + // last path on the stack, we don't omit the path. An error like + // "package A imports B: error loading C caused by B" would not be clearer + // if "imports B" were omitted. + if len(p.ImportStack) == 0 { + return p.Err.Error() + } + var optpos string + if p.Pos != "" { + optpos = "\n\t" + p.Pos + } + return "package " + strings.Join(p.ImportStack, "\n\timports ") + optpos + ": " + p.Err.Error() +} + +func (p *PackageError) Unwrap() error { return p.Err } + +// PackageError implements MarshalJSON so that Err is marshaled as a string +// and non-essential fields are omitted. +func (p *PackageError) MarshalJSON() ([]byte, error) { + perr := struct { + ImportStack []string + Pos string + Err string + }{p.ImportStack, p.Pos, p.Err.Error()} + return json.Marshal(perr) +} + +func (p *PackageError) setPos(posList []token.Position) { + if len(posList) == 0 { + return + } + pos := posList[0] + pos.Filename = base.ShortPath(pos.Filename) + p.Pos = pos.String() +} + +// ImportPathError is a type of error that prevents a package from being loaded +// for a given import path. When such a package is loaded, a *Package is +// returned with Err wrapping an ImportPathError: the error is attached to +// the imported package, not the importing package. +// +// The string returned by ImportPath must appear in the string returned by +// Error. Errors that wrap ImportPathError (such as PackageError) may omit +// the import path. +type ImportPathError interface { + error + ImportPath() string +} + +var ( + _ ImportPathError = (*importError)(nil) + _ ImportPathError = (*modload.ImportMissingError)(nil) + _ ImportPathError = (*modload.ImportMissingSumError)(nil) +) + +type importError struct { + importPath string + err error // created with fmt.Errorf +} + +func ImportErrorf(path, format string, args ...interface{}) ImportPathError { + err := &importError{importPath: path, err: fmt.Errorf(format, args...)} + if errStr := err.Error(); !strings.Contains(errStr, path) { + panic(fmt.Sprintf("path %q not in error %q", path, errStr)) + } + return err +} + +func (e *importError) Error() string { + return e.err.Error() +} + +func (e *importError) Unwrap() error { + // Don't return e.err directly, since we're only wrapping an error if %w + // was passed to ImportErrorf. + return errors.Unwrap(e.err) +} + +func (e *importError) ImportPath() string { + return e.importPath +} + +// An ImportStack is a stack of import paths, possibly with the suffix " (test)" appended. +// The import path of a test package is the import path of the corresponding +// non-test package with the suffix "_test" added. +type ImportStack []string + +func (s *ImportStack) Push(p string) { + *s = append(*s, p) +} + +func (s *ImportStack) Pop() { + *s = (*s)[0 : len(*s)-1] +} + +func (s *ImportStack) Copy() []string { + return append([]string{}, *s...) +} + +func (s *ImportStack) Top() string { + if len(*s) == 0 { + return "" + } + return (*s)[len(*s)-1] +} + +// shorterThan reports whether sp is shorter than t. +// We use this to record the shortest import sequence +// that leads to a particular package. +func (sp *ImportStack) shorterThan(t []string) bool { + s := *sp + if len(s) != len(t) { + return len(s) < len(t) + } + // If they are the same length, settle ties using string ordering. + for i := range s { + if s[i] != t[i] { + return s[i] < t[i] + } + } + return false // they are equal +} + +// packageCache is a lookup cache for LoadImport, +// so that if we look up a package multiple times +// we return the same pointer each time. +var packageCache = map[string]*Package{} + +// ClearPackageCache clears the in-memory package cache and the preload caches. +// It is only for use by GOPATH-based "go get". +// TODO(jayconrod): When GOPATH-based "go get" is removed, delete this function. +func ClearPackageCache() { + for name := range packageCache { + delete(packageCache, name) + } + resolvedImportCache.Clear() + packageDataCache.Clear() +} + +// ClearPackageCachePartial clears packages with the given import paths from the +// in-memory package cache and the preload caches. It is only for use by +// GOPATH-based "go get". +// TODO(jayconrod): When GOPATH-based "go get" is removed, delete this function. +func ClearPackageCachePartial(args []string) { + shouldDelete := make(map[string]bool) + for _, arg := range args { + shouldDelete[arg] = true + if p := packageCache[arg]; p != nil { + delete(packageCache, arg) + } + } + resolvedImportCache.DeleteIf(func(key interface{}) bool { + return shouldDelete[key.(importSpec).path] + }) + packageDataCache.DeleteIf(func(key interface{}) bool { + return shouldDelete[key.(string)] + }) +} + +// ReloadPackageNoFlags is like LoadImport but makes sure +// not to use the package cache. +// It is only for use by GOPATH-based "go get". +// TODO(rsc): When GOPATH-based "go get" is removed, delete this function. +func ReloadPackageNoFlags(arg string, stk *ImportStack) *Package { + p := packageCache[arg] + if p != nil { + delete(packageCache, arg) + resolvedImportCache.DeleteIf(func(key interface{}) bool { + return key.(importSpec).path == p.ImportPath + }) + packageDataCache.Delete(p.ImportPath) + } + return LoadImport(context.TODO(), arg, base.Cwd, nil, stk, nil, 0) +} + +// dirToImportPath returns the pseudo-import path we use for a package +// outside the Go path. It begins with _/ and then contains the full path +// to the directory. If the package lives in c:\home\gopher\my\pkg then +// the pseudo-import path is _/c_/home/gopher/my/pkg. +// Using a pseudo-import path like this makes the ./ imports no longer +// a special case, so that all the code to deal with ordinary imports works +// automatically. +func dirToImportPath(dir string) string { + return pathpkg.Join("_", strings.Map(makeImportValid, filepath.ToSlash(dir))) +} + +func makeImportValid(r rune) rune { + // Should match Go spec, compilers, and ../../go/parser/parser.go:/isValidImport. + const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD" + if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) { + return '_' + } + return r +} + +// Mode flags for loadImport and download (in get.go). +const ( + // ResolveImport means that loadImport should do import path expansion. + // That is, ResolveImport means that the import path came from + // a source file and has not been expanded yet to account for + // vendoring or possible module adjustment. + // Every import path should be loaded initially with ResolveImport, + // and then the expanded version (for example with the /vendor/ in it) + // gets recorded as the canonical import path. At that point, future loads + // of that package must not pass ResolveImport, because + // disallowVendor will reject direct use of paths containing /vendor/. + ResolveImport = 1 << iota + + // ResolveModule is for download (part of "go get") and indicates + // that the module adjustment should be done, but not vendor adjustment. + ResolveModule + + // GetTestDeps is for download (part of "go get") and indicates + // that test dependencies should be fetched too. + GetTestDeps +) + +// LoadImport scans the directory named by path, which must be an import path, +// but possibly a local import path (an absolute file system path or one beginning +// with ./ or ../). A local relative path is interpreted relative to srcDir. +// It returns a *Package describing the package found in that directory. +// LoadImport does not set tool flags and should only be used by +// this package, as part of a bigger load operation, and by GOPATH-based "go get". +// TODO(rsc): When GOPATH-based "go get" is removed, unexport this function. +func LoadImport(ctx context.Context, path, srcDir string, parent *Package, stk *ImportStack, importPos []token.Position, mode int) *Package { + return loadImport(ctx, nil, path, srcDir, parent, stk, importPos, mode) +} + +func loadImport(ctx context.Context, pre *preload, path, srcDir string, parent *Package, stk *ImportStack, importPos []token.Position, mode int) *Package { + if path == "" { + panic("LoadImport called with empty package path") + } + + var parentPath, parentRoot string + parentIsStd := false + if parent != nil { + parentPath = parent.ImportPath + parentRoot = parent.Root + parentIsStd = parent.Standard + } + bp, loaded, err := loadPackageData(path, parentPath, srcDir, parentRoot, parentIsStd, mode) + if loaded && pre != nil && !IgnoreImports { + pre.preloadImports(bp.Imports, bp) + } + if bp == nil { + if importErr, ok := err.(ImportPathError); !ok || importErr.ImportPath() != path { + // Only add path to the error's import stack if it's not already present on the error. + stk.Push(path) + defer stk.Pop() + } + return &Package{ + PackagePublic: PackagePublic{ + ImportPath: path, + Error: &PackageError{ + ImportStack: stk.Copy(), + Err: err, + }, + }, + } + } + + importPath := bp.ImportPath + p := packageCache[importPath] + if p != nil { + stk.Push(path) + p = reusePackage(p, stk) + stk.Pop() + } else { + p = new(Package) + p.Internal.Local = build.IsLocalImport(path) + p.ImportPath = importPath + packageCache[importPath] = p + + // Load package. + // loadPackageData may return bp != nil even if an error occurs, + // in order to return partial information. + p.load(ctx, path, stk, importPos, bp, err) + + if !cfg.ModulesEnabled && path != cleanImport(path) { + p.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: ImportErrorf(path, "non-canonical import path %q: should be %q", path, pathpkg.Clean(path)), + } + p.Incomplete = true + p.Error.setPos(importPos) + } + } + + // Checked on every import because the rules depend on the code doing the importing. + if perr := disallowInternal(srcDir, parent, parentPath, p, stk); perr != p { + perr.Error.setPos(importPos) + return perr + } + if mode&ResolveImport != 0 { + if perr := disallowVendor(srcDir, path, parentPath, p, stk); perr != p { + perr.Error.setPos(importPos) + return perr + } + } + + if p.Name == "main" && parent != nil && parent.Dir != p.Dir { + perr := *p + perr.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: ImportErrorf(path, "import %q is a program, not an importable package", path), + } + perr.Error.setPos(importPos) + return &perr + } + + if p.Internal.Local && parent != nil && !parent.Internal.Local { + perr := *p + var err error + if path == "." { + err = ImportErrorf(path, "%s: cannot import current directory", path) + } else { + err = ImportErrorf(path, "local import %q in non-local package", path) + } + perr.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: err, + } + perr.Error.setPos(importPos) + return &perr + } + + return p +} + +// loadPackageData loads information needed to construct a *Package. The result +// is cached, and later calls to loadPackageData for the same package will return +// the same data. +// +// loadPackageData returns a non-nil package even if err is non-nil unless +// the package path is malformed (for example, the path contains "mod/" or "@"). +// +// loadPackageData returns a boolean, loaded, which is true if this is the +// first time the package was loaded. Callers may preload imports in this case. +func loadPackageData(path, parentPath, parentDir, parentRoot string, parentIsStd bool, mode int) (bp *build.Package, loaded bool, err error) { + if path == "" { + panic("loadPackageData called with empty package path") + } + + if strings.HasPrefix(path, "mod/") { + // Paths beginning with "mod/" might accidentally + // look in the module cache directory tree in $GOPATH/pkg/mod/. + // This prefix is owned by the Go core for possible use in the + // standard library (since it does not begin with a domain name), + // so it's OK to disallow entirely. + return nil, false, fmt.Errorf("disallowed import path %q", path) + } + + if strings.Contains(path, "@") { + return nil, false, errors.New("can only use path@version syntax with 'go get' and 'go install' in module-aware mode") + } + + // Determine canonical package path and directory. + // For a local import the identifier is the pseudo-import path + // we create from the full directory to the package. + // Otherwise it is the usual import path. + // For vendored imports, it is the expanded form. + // + // Note that when modules are enabled, local import paths are normally + // canonicalized by modload.LoadPackages before now. However, if there's an + // error resolving a local path, it will be returned untransformed + // so that 'go list -e' reports something useful. + importKey := importSpec{ + path: path, + parentPath: parentPath, + parentDir: parentDir, + parentRoot: parentRoot, + parentIsStd: parentIsStd, + mode: mode, + } + r := resolvedImportCache.Do(importKey, func() interface{} { + var r resolvedImport + if build.IsLocalImport(path) { + r.dir = filepath.Join(parentDir, path) + r.path = dirToImportPath(r.dir) + } else if cfg.ModulesEnabled { + r.dir, r.path, r.err = modload.Lookup(parentPath, parentIsStd, path) + } else if mode&ResolveImport != 0 { + // We do our own path resolution, because we want to + // find out the key to use in packageCache without the + // overhead of repeated calls to buildContext.Import. + // The code is also needed in a few other places anyway. + r.path = resolveImportPath(path, parentPath, parentDir, parentRoot, parentIsStd) + } else if mode&ResolveModule != 0 { + r.path = moduleImportPath(path, parentPath, parentDir, parentRoot) + } + if r.path == "" { + r.path = path + } + return r + }).(resolvedImport) + // Invariant: r.path is set to the resolved import path. If the path cannot + // be resolved, r.path is set to path, the source import path. + // r.path is never empty. + + // Load the package from its directory. If we already found the package's + // directory when resolving its import path, use that. + data := packageDataCache.Do(r.path, func() interface{} { + loaded = true + var data packageData + if r.dir != "" { + var buildMode build.ImportMode + if !cfg.ModulesEnabled { + buildMode = build.ImportComment + } + data.p, data.err = cfg.BuildContext.ImportDir(r.dir, buildMode) + if data.p.Root == "" && cfg.ModulesEnabled { + if info := modload.PackageModuleInfo(path); info != nil { + data.p.Root = info.Dir + } + } + } else if r.err != nil { + data.p = new(build.Package) + data.err = r.err + } else if cfg.ModulesEnabled && path != "unsafe" { + data.p = new(build.Package) + data.err = fmt.Errorf("unknown import path %q: internal error: module loader did not resolve import", r.path) + } else { + buildMode := build.ImportComment + if mode&ResolveImport == 0 || r.path != path { + // Not vendoring, or we already found the vendored path. + buildMode |= build.IgnoreVendor + } + data.p, data.err = cfg.BuildContext.Import(r.path, parentDir, buildMode) + } + data.p.ImportPath = r.path + + // Set data.p.BinDir in cases where go/build.Context.Import + // may give us a path we don't want. + if !data.p.Goroot { + if cfg.GOBIN != "" { + data.p.BinDir = cfg.GOBIN + } else if cfg.ModulesEnabled { + data.p.BinDir = modload.BinDir() + } + } + + if !cfg.ModulesEnabled && data.err == nil && + data.p.ImportComment != "" && data.p.ImportComment != path && + !strings.Contains(path, "/vendor/") && !strings.HasPrefix(path, "vendor/") { + data.err = fmt.Errorf("code in directory %s expects import %q", data.p.Dir, data.p.ImportComment) + } + return data + }).(packageData) + + return data.p, loaded, data.err +} + +// importSpec describes an import declaration in source code. It is used as a +// cache key for resolvedImportCache. +type importSpec struct { + path string + parentPath, parentDir, parentRoot string + parentIsStd bool + mode int +} + +// resolvedImport holds a canonical identifier for a package. It may also contain +// a path to the package's directory and an error if one occurred. resolvedImport +// is the value type in resolvedImportCache. +type resolvedImport struct { + path, dir string + err error +} + +// packageData holds information loaded from a package. It is the value type +// in packageDataCache. +type packageData struct { + p *build.Package + err error +} + +// resolvedImportCache maps import strings (importSpec) to canonical package names +// (resolvedImport). +var resolvedImportCache par.Cache + +// packageDataCache maps canonical package names (string) to package metadata +// (packageData). +var packageDataCache par.Cache + +// preloadWorkerCount is the number of concurrent goroutines that can load +// packages. Experimentally, there are diminishing returns with more than +// 4 workers. This was measured on the following machines. +// +// * MacBookPro with a 4-core Intel Core i7 CPU +// * Linux workstation with 6-core Intel Xeon CPU +// * Linux workstation with 24-core Intel Xeon CPU +// +// It is very likely (though not confirmed) that this workload is limited +// by memory bandwidth. We don't have a good way to determine the number of +// workers that would saturate the bus though, so runtime.GOMAXPROCS +// seems like a reasonable default. +var preloadWorkerCount = runtime.GOMAXPROCS(0) + +// preload holds state for managing concurrent preloading of package data. +// +// A preload should be created with newPreload before loading a large +// package graph. flush must be called when package loading is complete +// to ensure preload goroutines are no longer active. This is necessary +// because of global mutable state that cannot safely be read and written +// concurrently. In particular, packageDataCache may be cleared by "go get" +// in GOPATH mode, and modload.loaded (accessed via modload.Lookup) may be +// modified by modload.LoadPackages. +type preload struct { + cancel chan struct{} + sema chan struct{} +} + +// newPreload creates a new preloader. flush must be called later to avoid +// accessing global state while it is being modified. +func newPreload() *preload { + pre := &preload{ + cancel: make(chan struct{}), + sema: make(chan struct{}, preloadWorkerCount), + } + return pre +} + +// preloadMatches loads data for package paths matched by patterns. +// When preloadMatches returns, some packages may not be loaded yet, but +// loadPackageData and loadImport are always safe to call. +func (pre *preload) preloadMatches(matches []*search.Match) { + for _, m := range matches { + for _, pkg := range m.Pkgs { + select { + case <-pre.cancel: + return + case pre.sema <- struct{}{}: + go func(pkg string) { + mode := 0 // don't use vendoring or module import resolution + bp, loaded, err := loadPackageData(pkg, "", base.Cwd, "", false, mode) + <-pre.sema + if bp != nil && loaded && err == nil && !IgnoreImports { + pre.preloadImports(bp.Imports, bp) + } + }(pkg) + } + } + } +} + +// preloadImports queues a list of imports for preloading. +// When preloadImports returns, some packages may not be loaded yet, +// but loadPackageData and loadImport are always safe to call. +func (pre *preload) preloadImports(imports []string, parent *build.Package) { + parentIsStd := parent.Goroot && parent.ImportPath != "" && search.IsStandardImportPath(parent.ImportPath) + for _, path := range imports { + if path == "C" || path == "unsafe" { + continue + } + select { + case <-pre.cancel: + return + case pre.sema <- struct{}{}: + go func(path string) { + bp, loaded, err := loadPackageData(path, parent.ImportPath, parent.Dir, parent.Root, parentIsStd, ResolveImport) + <-pre.sema + if bp != nil && loaded && err == nil && !IgnoreImports { + pre.preloadImports(bp.Imports, bp) + } + }(path) + } + } +} + +// flush stops pending preload operations. flush blocks until preload calls to +// loadPackageData have completed. The preloader will not make any new calls +// to loadPackageData. +func (pre *preload) flush() { + // flush is usually deferred. + // Don't hang program waiting for workers on panic. + if v := recover(); v != nil { + panic(v) + } + + close(pre.cancel) + for i := 0; i < preloadWorkerCount; i++ { + pre.sema <- struct{}{} + } +} + +func cleanImport(path string) string { + orig := path + path = pathpkg.Clean(path) + if strings.HasPrefix(orig, "./") && path != ".." && !strings.HasPrefix(path, "../") { + path = "./" + path + } + return path +} + +var isDirCache par.Cache + +func isDir(path string) bool { + return isDirCache.Do(path, func() interface{} { + fi, err := fsys.Stat(path) + return err == nil && fi.IsDir() + }).(bool) +} + +// ResolveImportPath returns the true meaning of path when it appears in parent. +// There are two different resolutions applied. +// First, there is Go 1.5 vendoring (golang.org/s/go15vendor). +// If vendor expansion doesn't trigger, then the path is also subject to +// Go 1.11 module legacy conversion (golang.org/issue/25069). +func ResolveImportPath(parent *Package, path string) (found string) { + var parentPath, parentDir, parentRoot string + parentIsStd := false + if parent != nil { + parentPath = parent.ImportPath + parentDir = parent.Dir + parentRoot = parent.Root + parentIsStd = parent.Standard + } + return resolveImportPath(path, parentPath, parentDir, parentRoot, parentIsStd) +} + +func resolveImportPath(path, parentPath, parentDir, parentRoot string, parentIsStd bool) (found string) { + if cfg.ModulesEnabled { + if _, p, e := modload.Lookup(parentPath, parentIsStd, path); e == nil { + return p + } + return path + } + found = vendoredImportPath(path, parentPath, parentDir, parentRoot) + if found != path { + return found + } + return moduleImportPath(path, parentPath, parentDir, parentRoot) +} + +// dirAndRoot returns the source directory and workspace root +// for the package p, guaranteeing that root is a path prefix of dir. +func dirAndRoot(path string, dir, root string) (string, string) { + origDir, origRoot := dir, root + dir = filepath.Clean(dir) + root = filepath.Join(root, "src") + if !str.HasFilePathPrefix(dir, root) || path != "command-line-arguments" && filepath.Join(root, path) != dir { + // Look for symlinks before reporting error. + dir = expandPath(dir) + root = expandPath(root) + } + + if !str.HasFilePathPrefix(dir, root) || len(dir) <= len(root) || dir[len(root)] != filepath.Separator || path != "command-line-arguments" && !build.IsLocalImport(path) && filepath.Join(root, path) != dir { + base.Fatalf("unexpected directory layout:\n"+ + " import path: %s\n"+ + " root: %s\n"+ + " dir: %s\n"+ + " expand root: %s\n"+ + " expand dir: %s\n"+ + " separator: %s", + path, + filepath.Join(origRoot, "src"), + filepath.Clean(origDir), + origRoot, + origDir, + string(filepath.Separator)) + } + + return dir, root +} + +// vendoredImportPath returns the vendor-expansion of path when it appears in parent. +// If parent is x/y/z, then path might expand to x/y/z/vendor/path, x/y/vendor/path, +// x/vendor/path, vendor/path, or else stay path if none of those exist. +// vendoredImportPath returns the expanded path or, if no expansion is found, the original. +func vendoredImportPath(path, parentPath, parentDir, parentRoot string) (found string) { + if parentRoot == "" { + return path + } + + dir, root := dirAndRoot(parentPath, parentDir, parentRoot) + + vpath := "vendor/" + path + for i := len(dir); i >= len(root); i-- { + if i < len(dir) && dir[i] != filepath.Separator { + continue + } + // Note: checking for the vendor directory before checking + // for the vendor/path directory helps us hit the + // isDir cache more often. It also helps us prepare a more useful + // list of places we looked, to report when an import is not found. + if !isDir(filepath.Join(dir[:i], "vendor")) { + continue + } + targ := filepath.Join(dir[:i], vpath) + if isDir(targ) && hasGoFiles(targ) { + importPath := parentPath + if importPath == "command-line-arguments" { + // If parent.ImportPath is 'command-line-arguments'. + // set to relative directory to root (also chopped root directory) + importPath = dir[len(root)+1:] + } + // We started with parent's dir c:\gopath\src\foo\bar\baz\quux\xyzzy. + // We know the import path for parent's dir. + // We chopped off some number of path elements and + // added vendor\path to produce c:\gopath\src\foo\bar\baz\vendor\path. + // Now we want to know the import path for that directory. + // Construct it by chopping the same number of path elements + // (actually the same number of bytes) from parent's import path + // and then append /vendor/path. + chopped := len(dir) - i + if chopped == len(importPath)+1 { + // We walked up from c:\gopath\src\foo\bar + // and found c:\gopath\src\vendor\path. + // We chopped \foo\bar (length 8) but the import path is "foo/bar" (length 7). + // Use "vendor/path" without any prefix. + return vpath + } + return importPath[:len(importPath)-chopped] + "/" + vpath + } + } + return path +} + +var ( + modulePrefix = []byte("\nmodule ") + goModPathCache par.Cache +) + +// goModPath returns the module path in the go.mod in dir, if any. +func goModPath(dir string) (path string) { + return goModPathCache.Do(dir, func() interface{} { + data, err := os.ReadFile(filepath.Join(dir, "go.mod")) + if err != nil { + return "" + } + var i int + if bytes.HasPrefix(data, modulePrefix[1:]) { + i = 0 + } else { + i = bytes.Index(data, modulePrefix) + if i < 0 { + return "" + } + i++ + } + line := data[i:] + + // Cut line at \n, drop trailing \r if present. + if j := bytes.IndexByte(line, '\n'); j >= 0 { + line = line[:j] + } + if line[len(line)-1] == '\r' { + line = line[:len(line)-1] + } + line = line[len("module "):] + + // If quoted, unquote. + path = strings.TrimSpace(string(line)) + if path != "" && path[0] == '"' { + s, err := strconv.Unquote(path) + if err != nil { + return "" + } + path = s + } + return path + }).(string) +} + +// findVersionElement returns the slice indices of the final version element /vN in path. +// If there is no such element, it returns -1, -1. +func findVersionElement(path string) (i, j int) { + j = len(path) + for i = len(path) - 1; i >= 0; i-- { + if path[i] == '/' { + if isVersionElement(path[i+1 : j]) { + return i, j + } + j = i + } + } + return -1, -1 +} + +// isVersionElement reports whether s is a well-formed path version element: +// v2, v3, v10, etc, but not v0, v05, v1. +func isVersionElement(s string) bool { + if len(s) < 2 || s[0] != 'v' || s[1] == '0' || s[1] == '1' && len(s) == 2 { + return false + } + for i := 1; i < len(s); i++ { + if s[i] < '0' || '9' < s[i] { + return false + } + } + return true +} + +// moduleImportPath translates import paths found in go modules +// back down to paths that can be resolved in ordinary builds. +// +// Define “new” code as code with a go.mod file in the same directory +// or a parent directory. If an import in new code says x/y/v2/z but +// x/y/v2/z does not exist and x/y/go.mod says “module x/y/v2”, +// then go build will read the import as x/y/z instead. +// See golang.org/issue/25069. +func moduleImportPath(path, parentPath, parentDir, parentRoot string) (found string) { + if parentRoot == "" { + return path + } + + // If there are no vN elements in path, leave it alone. + // (The code below would do the same, but only after + // some other file system accesses that we can avoid + // here by returning early.) + if i, _ := findVersionElement(path); i < 0 { + return path + } + + dir, root := dirAndRoot(parentPath, parentDir, parentRoot) + + // Consider dir and parents, up to and including root. + for i := len(dir); i >= len(root); i-- { + if i < len(dir) && dir[i] != filepath.Separator { + continue + } + if goModPath(dir[:i]) != "" { + goto HaveGoMod + } + } + // This code is not in a tree with a go.mod, + // so apply no changes to the path. + return path + +HaveGoMod: + // This import is in a tree with a go.mod. + // Allow it to refer to code in GOPATH/src/x/y/z as x/y/v2/z + // if GOPATH/src/x/y/go.mod says module "x/y/v2", + + // If x/y/v2/z exists, use it unmodified. + if bp, _ := cfg.BuildContext.Import(path, "", build.IgnoreVendor); bp.Dir != "" { + return path + } + + // Otherwise look for a go.mod supplying a version element. + // Some version-like elements may appear in paths but not + // be module versions; we skip over those to look for module + // versions. For example the module m/v2 might have a + // package m/v2/api/v1/foo. + limit := len(path) + for limit > 0 { + i, j := findVersionElement(path[:limit]) + if i < 0 { + return path + } + if bp, _ := cfg.BuildContext.Import(path[:i], "", build.IgnoreVendor); bp.Dir != "" { + if mpath := goModPath(bp.Dir); mpath != "" { + // Found a valid go.mod file, so we're stopping the search. + // If the path is m/v2/p and we found m/go.mod that says + // "module m/v2", then we return "m/p". + if mpath == path[:j] { + return path[:i] + path[j:] + } + // Otherwise just return the original path. + // We didn't find anything worth rewriting, + // and the go.mod indicates that we should + // not consider parent directories. + return path + } + } + limit = i + } + return path +} + +// hasGoFiles reports whether dir contains any files with names ending in .go. +// For a vendor check we must exclude directories that contain no .go files. +// Otherwise it is not possible to vendor just a/b/c and still import the +// non-vendored a/b. See golang.org/issue/13832. +func hasGoFiles(dir string) bool { + files, _ := os.ReadDir(dir) + for _, f := range files { + if !f.IsDir() && strings.HasSuffix(f.Name(), ".go") { + return true + } + } + return false +} + +// reusePackage reuses package p to satisfy the import at the top +// of the import stack stk. If this use causes an import loop, +// reusePackage updates p's error information to record the loop. +func reusePackage(p *Package, stk *ImportStack) *Package { + // We use p.Internal.Imports==nil to detect a package that + // is in the midst of its own loadPackage call + // (all the recursion below happens before p.Internal.Imports gets set). + if p.Internal.Imports == nil { + if p.Error == nil { + p.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: errors.New("import cycle not allowed"), + IsImportCycle: true, + } + } else if !p.Error.IsImportCycle { + // If the error is already set, but it does not indicate that + // we are in an import cycle, set IsImportCycle so that we don't + // end up stuck in a loop down the road. + p.Error.IsImportCycle = true + } + p.Incomplete = true + } + // Don't rewrite the import stack in the error if we have an import cycle. + // If we do, we'll lose the path that describes the cycle. + if p.Error != nil && !p.Error.IsImportCycle && stk.shorterThan(p.Error.ImportStack) { + p.Error.ImportStack = stk.Copy() + } + return p +} + +// disallowInternal checks that srcDir (containing package importerPath, if non-empty) +// is allowed to import p. +// If the import is allowed, disallowInternal returns the original package p. +// If not, it returns a new package containing just an appropriate error. +func disallowInternal(srcDir string, importer *Package, importerPath string, p *Package, stk *ImportStack) *Package { + // golang.org/s/go14internal: + // An import of a path containing the element “internal” + // is disallowed if the importing code is outside the tree + // rooted at the parent of the “internal” directory. + + // There was an error loading the package; stop here. + if p.Error != nil { + return p + } + + // The generated 'testmain' package is allowed to access testing/internal/..., + // as if it were generated into the testing directory tree + // (it's actually in a temporary directory outside any Go tree). + // This cleans up a former kludge in passing functionality to the testing package. + if str.HasPathPrefix(p.ImportPath, "testing/internal") && importerPath == "testmain" { + return p + } + + // We can't check standard packages with gccgo. + if cfg.BuildContext.Compiler == "gccgo" && p.Standard { + return p + } + + // The sort package depends on internal/reflectlite, but during bootstrap + // the path rewriting causes the normal internal checks to fail. + // Instead, just ignore the internal rules during bootstrap. + if p.Standard && strings.HasPrefix(importerPath, "bootstrap/") { + return p + } + + // importerPath is empty: we started + // with a name given on the command line, not an + // import. Anything listed on the command line is fine. + if importerPath == "" { + return p + } + + // Check for "internal" element: three cases depending on begin of string and/or end of string. + i, ok := findInternal(p.ImportPath) + if !ok { + return p + } + + // Internal is present. + // Map import path back to directory corresponding to parent of internal. + if i > 0 { + i-- // rewind over slash in ".../internal" + } + + if p.Module == nil { + parent := p.Dir[:i+len(p.Dir)-len(p.ImportPath)] + + if str.HasFilePathPrefix(filepath.Clean(srcDir), filepath.Clean(parent)) { + return p + } + + // Look for symlinks before reporting error. + srcDir = expandPath(srcDir) + parent = expandPath(parent) + if str.HasFilePathPrefix(filepath.Clean(srcDir), filepath.Clean(parent)) { + return p + } + } else { + // p is in a module, so make it available based on the importer's import path instead + // of the file path (https://golang.org/issue/23970). + if importer.Internal.CmdlineFiles { + // The importer is a list of command-line files. + // Pretend that the import path is the import path of the + // directory containing them. + // If the directory is outside the main module, this will resolve to ".", + // which is not a prefix of any valid module. + importerPath = modload.DirImportPath(importer.Dir) + } + parentOfInternal := p.ImportPath[:i] + if str.HasPathPrefix(importerPath, parentOfInternal) { + return p + } + } + + // Internal is present, and srcDir is outside parent's tree. Not allowed. + perr := *p + perr.Error = &PackageError{ + alwaysPrintStack: true, + ImportStack: stk.Copy(), + Err: ImportErrorf(p.ImportPath, "use of internal package "+p.ImportPath+" not allowed"), + } + perr.Incomplete = true + return &perr +} + +// findInternal looks for the final "internal" path element in the given import path. +// If there isn't one, findInternal returns ok=false. +// Otherwise, findInternal returns ok=true and the index of the "internal". +func findInternal(path string) (index int, ok bool) { + // Three cases, depending on internal at start/end of string or not. + // The order matters: we must return the index of the final element, + // because the final one produces the most restrictive requirement + // on the importer. + switch { + case strings.HasSuffix(path, "/internal"): + return len(path) - len("internal"), true + case strings.Contains(path, "/internal/"): + return strings.LastIndex(path, "/internal/") + 1, true + case path == "internal", strings.HasPrefix(path, "internal/"): + return 0, true + } + return 0, false +} + +// disallowVendor checks that srcDir is allowed to import p as path. +// If the import is allowed, disallowVendor returns the original package p. +// If not, it returns a new package containing just an appropriate error. +func disallowVendor(srcDir string, path string, importerPath string, p *Package, stk *ImportStack) *Package { + // If the importerPath is empty, we started + // with a name given on the command line, not an + // import. Anything listed on the command line is fine. + if importerPath == "" { + return p + } + + if perr := disallowVendorVisibility(srcDir, p, importerPath, stk); perr != p { + return perr + } + + // Paths like x/vendor/y must be imported as y, never as x/vendor/y. + if i, ok := FindVendor(path); ok { + perr := *p + perr.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: ImportErrorf(path, "%s must be imported as %s", path, path[i+len("vendor/"):]), + } + perr.Incomplete = true + return &perr + } + + return p +} + +// disallowVendorVisibility checks that srcDir is allowed to import p. +// The rules are the same as for /internal/ except that a path ending in /vendor +// is not subject to the rules, only subdirectories of vendor. +// This allows people to have packages and commands named vendor, +// for maximal compatibility with existing source trees. +func disallowVendorVisibility(srcDir string, p *Package, importerPath string, stk *ImportStack) *Package { + // The stack does not include p.ImportPath. + // If there's nothing on the stack, we started + // with a name given on the command line, not an + // import. Anything listed on the command line is fine. + if importerPath == "" { + return p + } + + // Check for "vendor" element. + i, ok := FindVendor(p.ImportPath) + if !ok { + return p + } + + // Vendor is present. + // Map import path back to directory corresponding to parent of vendor. + if i > 0 { + i-- // rewind over slash in ".../vendor" + } + truncateTo := i + len(p.Dir) - len(p.ImportPath) + if truncateTo < 0 || len(p.Dir) < truncateTo { + return p + } + parent := p.Dir[:truncateTo] + if str.HasFilePathPrefix(filepath.Clean(srcDir), filepath.Clean(parent)) { + return p + } + + // Look for symlinks before reporting error. + srcDir = expandPath(srcDir) + parent = expandPath(parent) + if str.HasFilePathPrefix(filepath.Clean(srcDir), filepath.Clean(parent)) { + return p + } + + // Vendor is present, and srcDir is outside parent's tree. Not allowed. + perr := *p + perr.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: errors.New("use of vendored package not allowed"), + } + perr.Incomplete = true + return &perr +} + +// FindVendor looks for the last non-terminating "vendor" path element in the given import path. +// If there isn't one, FindVendor returns ok=false. +// Otherwise, FindVendor returns ok=true and the index of the "vendor". +// +// Note that terminating "vendor" elements don't count: "x/vendor" is its own package, +// not the vendored copy of an import "" (the empty import path). +// This will allow people to have packages or commands named vendor. +// This may help reduce breakage, or it may just be confusing. We'll see. +func FindVendor(path string) (index int, ok bool) { + // Two cases, depending on internal at start of string or not. + // The order matters: we must return the index of the final element, + // because the final one is where the effective import path starts. + switch { + case strings.Contains(path, "/vendor/"): + return strings.LastIndex(path, "/vendor/") + 1, true + case strings.HasPrefix(path, "vendor/"): + return 0, true + } + return 0, false +} + +type TargetDir int + +const ( + ToTool TargetDir = iota // to GOROOT/pkg/tool (default for cmd/*) + ToBin // to bin dir inside package root (default for non-cmd/*) + StalePath // an old import path; fail to build +) + +// InstallTargetDir reports the target directory for installing the command p. +func InstallTargetDir(p *Package) TargetDir { + if strings.HasPrefix(p.ImportPath, "code.google.com/p/go.tools/cmd/") { + return StalePath + } + if p.Goroot && strings.HasPrefix(p.ImportPath, "cmd/") && p.Name == "main" { + switch p.ImportPath { + case "cmd/go", "cmd/gofmt": + return ToBin + } + return ToTool + } + return ToBin +} + +var cgoExclude = map[string]bool{ + "runtime/cgo": true, +} + +var cgoSyscallExclude = map[string]bool{ + "runtime/cgo": true, + "runtime/race": true, + "runtime/msan": true, +} + +var foldPath = make(map[string]string) + +// exeFromImportPath returns an executable name +// for a package using the import path. +// +// The executable name is the last element of the import path. +// In module-aware mode, an additional rule is used on import paths +// consisting of two or more path elements. If the last element is +// a vN path element specifying the major version, then the +// second last element of the import path is used instead. +func (p *Package) exeFromImportPath() string { + _, elem := pathpkg.Split(p.ImportPath) + if cfg.ModulesEnabled { + // If this is example.com/mycmd/v2, it's more useful to + // install it as mycmd than as v2. See golang.org/issue/24667. + if elem != p.ImportPath && isVersionElement(elem) { + _, elem = pathpkg.Split(pathpkg.Dir(p.ImportPath)) + } + } + return elem +} + +// exeFromFiles returns an executable name for a package +// using the first element in GoFiles or CgoFiles collections without the prefix. +// +// Returns empty string in case of empty collection. +func (p *Package) exeFromFiles() string { + var src string + if len(p.GoFiles) > 0 { + src = p.GoFiles[0] + } else if len(p.CgoFiles) > 0 { + src = p.CgoFiles[0] + } else { + return "" + } + _, elem := filepath.Split(src) + return elem[:len(elem)-len(".go")] +} + +// DefaultExecName returns the default executable name for a package +func (p *Package) DefaultExecName() string { + if p.Internal.CmdlineFiles { + return p.exeFromFiles() + } + return p.exeFromImportPath() +} + +// load populates p using information from bp, err, which should +// be the result of calling build.Context.Import. +// stk contains the import stack, not including path itself. +func (p *Package) load(ctx context.Context, path string, stk *ImportStack, importPos []token.Position, bp *build.Package, err error) { + p.copyBuild(bp) + + // The localPrefix is the path we interpret ./ imports relative to. + // Synthesized main packages sometimes override this. + if p.Internal.Local { + p.Internal.LocalPrefix = dirToImportPath(p.Dir) + } + + // setError sets p.Error if it hasn't already been set. We may proceed + // after encountering some errors so that 'go list -e' has more complete + // output. If there's more than one error, we should report the first. + setError := func(err error) { + if p.Error == nil { + p.Error = &PackageError{ + ImportStack: stk.Copy(), + Err: err, + } + + // Add the importer's position information if the import position exists, and + // the current package being examined is the importer. + // If we have not yet accepted package p onto the import stack, + // then the cause of the error is not within p itself: the error + // must be either in an explicit command-line argument, + // or on the importer side (indicated by a non-empty importPos). + if path != stk.Top() && len(importPos) > 0 { + p.Error.setPos(importPos) + } + } + } + + if err != nil { + p.Incomplete = true + p.setLoadPackageDataError(err, path, stk, importPos) + } + + useBindir := p.Name == "main" + if !p.Standard { + switch cfg.BuildBuildmode { + case "c-archive", "c-shared", "plugin": + useBindir = false + } + } + + if useBindir { + // Report an error when the old code.google.com/p/go.tools paths are used. + if InstallTargetDir(p) == StalePath { + // TODO(matloob): remove this branch, and StalePath itself. code.google.com/p/go is so + // old, even this code checking for it is stale now! + newPath := strings.Replace(p.ImportPath, "code.google.com/p/go.", "golang.org/x/", 1) + e := ImportErrorf(p.ImportPath, "the %v command has moved; use %v instead.", p.ImportPath, newPath) + setError(e) + return + } + elem := p.DefaultExecName() + full := cfg.BuildContext.GOOS + "_" + cfg.BuildContext.GOARCH + "/" + elem + if cfg.BuildContext.GOOS != base.ToolGOOS || cfg.BuildContext.GOARCH != base.ToolGOARCH { + // Install cross-compiled binaries to subdirectories of bin. + elem = full + } + if p.Internal.Build.BinDir == "" && cfg.ModulesEnabled { + p.Internal.Build.BinDir = modload.BinDir() + } + if p.Internal.Build.BinDir != "" { + // Install to GOBIN or bin of GOPATH entry. + p.Target = filepath.Join(p.Internal.Build.BinDir, elem) + if !p.Goroot && strings.Contains(elem, "/") && cfg.GOBIN != "" { + // Do not create $GOBIN/goos_goarch/elem. + p.Target = "" + p.Internal.GobinSubdir = true + } + } + if InstallTargetDir(p) == ToTool { + // This is for 'go tool'. + // Override all the usual logic and force it into the tool directory. + if cfg.BuildToolchainName == "gccgo" { + p.Target = filepath.Join(base.ToolDir, elem) + } else { + p.Target = filepath.Join(cfg.GOROOTpkg, "tool", full) + } + } + if p.Target != "" && cfg.BuildContext.GOOS == "windows" { + p.Target += ".exe" + } + } else if p.Internal.Local { + // Local import turned into absolute path. + // No permanent install target. + p.Target = "" + } else { + p.Target = p.Internal.Build.PkgObj + if cfg.BuildLinkshared && p.Target != "" { + // TODO(bcmills): The reliance on p.Target implies that -linkshared does + // not work for any package that lacks a Target — such as a non-main + // package in module mode. We should probably fix that. + shlibnamefile := p.Target[:len(p.Target)-2] + ".shlibname" + shlib, err := os.ReadFile(shlibnamefile) + if err != nil && !os.IsNotExist(err) { + base.Fatalf("reading shlibname: %v", err) + } + if err == nil { + libname := strings.TrimSpace(string(shlib)) + if cfg.BuildContext.Compiler == "gccgo" { + p.Shlib = filepath.Join(p.Internal.Build.PkgTargetRoot, "shlibs", libname) + } else { + p.Shlib = filepath.Join(p.Internal.Build.PkgTargetRoot, libname) + } + } + } + } + + // Build augmented import list to add implicit dependencies. + // Be careful not to add imports twice, just to avoid confusion. + importPaths := p.Imports + addImport := func(path string, forCompiler bool) { + for _, p := range importPaths { + if path == p { + return + } + } + importPaths = append(importPaths, path) + if forCompiler { + p.Internal.CompiledImports = append(p.Internal.CompiledImports, path) + } + } + + // Cgo translation adds imports of "unsafe", "runtime/cgo" and "syscall", + // except for certain packages, to avoid circular dependencies. + if p.UsesCgo() { + addImport("unsafe", true) + } + if p.UsesCgo() && (!p.Standard || !cgoExclude[p.ImportPath]) && cfg.BuildContext.Compiler != "gccgo" { + addImport("runtime/cgo", true) + } + if p.UsesCgo() && (!p.Standard || !cgoSyscallExclude[p.ImportPath]) { + addImport("syscall", true) + } + + // SWIG adds imports of some standard packages. + if p.UsesSwig() { + addImport("unsafe", true) + if cfg.BuildContext.Compiler != "gccgo" { + addImport("runtime/cgo", true) + } + addImport("syscall", true) + addImport("sync", true) + + // TODO: The .swig and .swigcxx files can use + // %go_import directives to import other packages. + } + + // The linker loads implicit dependencies. + if p.Name == "main" && !p.Internal.ForceLibrary { + for _, dep := range LinkerDeps(p) { + addImport(dep, false) + } + } + + // Check for case-insensitive collisions of import paths. + fold := str.ToFold(p.ImportPath) + if other := foldPath[fold]; other == "" { + foldPath[fold] = p.ImportPath + } else if other != p.ImportPath { + setError(ImportErrorf(p.ImportPath, "case-insensitive import collision: %q and %q", p.ImportPath, other)) + return + } + + if !SafeArg(p.ImportPath) { + setError(ImportErrorf(p.ImportPath, "invalid import path %q", p.ImportPath)) + return + } + + // Errors after this point are caused by this package, not the importing + // package. Pushing the path here prevents us from reporting the error + // with the position of the import declaration. + stk.Push(path) + defer stk.Pop() + + p.EmbedFiles, p.Internal.Embed, err = resolveEmbed(p.Dir, p.EmbedPatterns) + if err != nil { + p.Incomplete = true + setError(err) + embedErr := err.(*EmbedError) + p.Error.setPos(p.Internal.Build.EmbedPatternPos[embedErr.Pattern]) + } + + // Check for case-insensitive collision of input files. + // To avoid problems on case-insensitive files, we reject any package + // where two different input files have equal names under a case-insensitive + // comparison. + inputs := p.AllFiles() + f1, f2 := str.FoldDup(inputs) + if f1 != "" { + setError(fmt.Errorf("case-insensitive file name collision: %q and %q", f1, f2)) + return + } + + // If first letter of input file is ASCII, it must be alphanumeric. + // This avoids files turning into flags when invoking commands, + // and other problems we haven't thought of yet. + // Also, _cgo_ files must be generated by us, not supplied. + // They are allowed to have //go:cgo_ldflag directives. + // The directory scan ignores files beginning with _, + // so we shouldn't see any _cgo_ files anyway, but just be safe. + for _, file := range inputs { + if !SafeArg(file) || strings.HasPrefix(file, "_cgo_") { + setError(fmt.Errorf("invalid input file name %q", file)) + return + } + } + if name := pathpkg.Base(p.ImportPath); !SafeArg(name) { + setError(fmt.Errorf("invalid input directory name %q", name)) + return + } + + // Build list of imported packages and full dependency list. + imports := make([]*Package, 0, len(p.Imports)) + for i, path := range importPaths { + if path == "C" { + continue + } + p1 := LoadImport(ctx, path, p.Dir, p, stk, p.Internal.Build.ImportPos[path], ResolveImport) + + path = p1.ImportPath + importPaths[i] = path + if i < len(p.Imports) { + p.Imports[i] = path + } + + imports = append(imports, p1) + if p1.Incomplete { + p.Incomplete = true + } + } + p.Internal.Imports = imports + p.collectDeps() + + // unsafe is a fake package. + if p.Standard && (p.ImportPath == "unsafe" || cfg.BuildContext.Compiler == "gccgo") { + p.Target = "" + } + + // If cgo is not enabled, ignore cgo supporting sources + // just as we ignore go files containing import "C". + if !cfg.BuildContext.CgoEnabled { + p.CFiles = nil + p.CXXFiles = nil + p.MFiles = nil + p.SwigFiles = nil + p.SwigCXXFiles = nil + // Note that SFiles are okay (they go to the Go assembler) + // and HFiles are okay (they might be used by the SFiles). + // Also Sysofiles are okay (they might not contain object + // code; see issue #16050). + } + + // The gc toolchain only permits C source files with cgo or SWIG. + if len(p.CFiles) > 0 && !p.UsesCgo() && !p.UsesSwig() && cfg.BuildContext.Compiler == "gc" { + setError(fmt.Errorf("C source files not allowed when not using cgo or SWIG: %s", strings.Join(p.CFiles, " "))) + return + } + + // C++, Objective-C, and Fortran source files are permitted only with cgo or SWIG, + // regardless of toolchain. + if len(p.CXXFiles) > 0 && !p.UsesCgo() && !p.UsesSwig() { + setError(fmt.Errorf("C++ source files not allowed when not using cgo or SWIG: %s", strings.Join(p.CXXFiles, " "))) + return + } + if len(p.MFiles) > 0 && !p.UsesCgo() && !p.UsesSwig() { + setError(fmt.Errorf("Objective-C source files not allowed when not using cgo or SWIG: %s", strings.Join(p.MFiles, " "))) + return + } + if len(p.FFiles) > 0 && !p.UsesCgo() && !p.UsesSwig() { + setError(fmt.Errorf("Fortran source files not allowed when not using cgo or SWIG: %s", strings.Join(p.FFiles, " "))) + return + } + + if cfg.ModulesEnabled && p.Error == nil { + mainPath := p.ImportPath + if p.Internal.CmdlineFiles { + mainPath = "command-line-arguments" + } + p.Module = modload.PackageModuleInfo(mainPath) + if p.Name == "main" && len(p.DepsErrors) == 0 { + p.Internal.BuildInfo = modload.PackageBuildInfo(mainPath, p.Deps) + } + } +} + +// An EmbedError indicates a problem with a go:embed directive. +type EmbedError struct { + Pattern string + Err error +} + +func (e *EmbedError) Error() string { + return fmt.Sprintf("pattern %s: %v", e.Pattern, e.Err) +} + +func (e *EmbedError) Unwrap() error { + return e.Err +} + +// ResolveEmbed resolves //go:embed patterns and returns only the file list. +// For use by go mod vendor to find embedded files it should copy into the +// vendor directory. +// TODO(#42504): Once go mod vendor uses load.PackagesAndErrors, just +// call (*Package).ResolveEmbed +func ResolveEmbed(dir string, patterns []string) ([]string, error) { + files, _, err := resolveEmbed(dir, patterns) + return files, err +} + +// resolveEmbed resolves //go:embed patterns to precise file lists. +// It sets files to the list of unique files matched (for go list), +// and it sets pmap to the more precise mapping from +// patterns to files. +func resolveEmbed(pkgdir string, patterns []string) (files []string, pmap map[string][]string, err error) { + var pattern string + defer func() { + if err != nil { + err = &EmbedError{ + Pattern: pattern, + Err: err, + } + } + }() + + // TODO(rsc): All these messages need position information for better error reports. + pmap = make(map[string][]string) + have := make(map[string]int) + dirOK := make(map[string]bool) + pid := 0 // pattern ID, to allow reuse of have map + for _, pattern = range patterns { + pid++ + + // Check pattern is valid for //go:embed. + if _, err := path.Match(pattern, ""); err != nil || !validEmbedPattern(pattern) { + return nil, nil, fmt.Errorf("invalid pattern syntax") + } + + // Glob to find matches. + match, err := fsys.Glob(pkgdir + string(filepath.Separator) + filepath.FromSlash(pattern)) + if err != nil { + return nil, nil, err + } + + // Filter list of matches down to the ones that will still exist when + // the directory is packaged up as a module. (If p.Dir is in the module cache, + // only those files exist already, but if p.Dir is in the current module, + // then there may be other things lying around, like symbolic links or .git directories.) + var list []string + for _, file := range match { + rel := filepath.ToSlash(file[len(pkgdir)+1:]) // file, relative to p.Dir + + what := "file" + info, err := fsys.Lstat(file) + if err != nil { + return nil, nil, err + } + if info.IsDir() { + what = "directory" + } + + // Check that directories along path do not begin a new module + // (do not contain a go.mod). + for dir := file; len(dir) > len(pkgdir)+1 && !dirOK[dir]; dir = filepath.Dir(dir) { + if _, err := fsys.Stat(filepath.Join(dir, "go.mod")); err == nil { + return nil, nil, fmt.Errorf("cannot embed %s %s: in different module", what, rel) + } + if dir != file { + if info, err := fsys.Lstat(dir); err == nil && !info.IsDir() { + return nil, nil, fmt.Errorf("cannot embed %s %s: in non-directory %s", what, rel, dir[len(pkgdir)+1:]) + } + } + dirOK[dir] = true + if elem := filepath.Base(dir); isBadEmbedName(elem) { + if dir == file { + return nil, nil, fmt.Errorf("cannot embed %s %s: invalid name %s", what, rel, elem) + } else { + return nil, nil, fmt.Errorf("cannot embed %s %s: in invalid directory %s", what, rel, elem) + } + } + } + + switch { + default: + return nil, nil, fmt.Errorf("cannot embed irregular file %s", rel) + + case info.Mode().IsRegular(): + if have[rel] != pid { + have[rel] = pid + list = append(list, rel) + } + + case info.IsDir(): + // Gather all files in the named directory, stopping at module boundaries + // and ignoring files that wouldn't be packaged into a module. + count := 0 + err := fsys.Walk(file, func(path string, info os.FileInfo, err error) error { + if err != nil { + return err + } + rel := filepath.ToSlash(path[len(pkgdir)+1:]) + name := info.Name() + if path != file && (isBadEmbedName(name) || name[0] == '.' || name[0] == '_') { + // Ignore bad names, assuming they won't go into modules. + // Also avoid hidden files that user may not know about. + // See golang.org/issue/42328. + if info.IsDir() { + return fs.SkipDir + } + return nil + } + if info.IsDir() { + if _, err := fsys.Stat(filepath.Join(path, "go.mod")); err == nil { + return filepath.SkipDir + } + return nil + } + if !info.Mode().IsRegular() { + return nil + } + count++ + if have[rel] != pid { + have[rel] = pid + list = append(list, rel) + } + return nil + }) + if err != nil { + return nil, nil, err + } + if count == 0 { + return nil, nil, fmt.Errorf("cannot embed directory %s: contains no embeddable files", rel) + } + } + } + + if len(list) == 0 { + return nil, nil, fmt.Errorf("no matching files found") + } + sort.Strings(list) + pmap[pattern] = list + } + + for file := range have { + files = append(files, file) + } + sort.Strings(files) + return files, pmap, nil +} + +func validEmbedPattern(pattern string) bool { + return pattern != "." && fs.ValidPath(pattern) +} + +// isBadEmbedName reports whether name is the base name of a file that +// can't or won't be included in modules and therefore shouldn't be treated +// as existing for embedding. +func isBadEmbedName(name string) bool { + if err := module.CheckFilePath(name); err != nil { + return true + } + switch name { + // Empty string should be impossible but make it bad. + case "": + return true + // Version control directories won't be present in module. + case ".bzr", ".hg", ".git", ".svn": + return true + } + return false +} + +// collectDeps populates p.Deps and p.DepsErrors by iterating over +// p.Internal.Imports. +// +// TODO(jayconrod): collectDeps iterates over transitive imports for every +// package. We should only need to visit direct imports. +func (p *Package) collectDeps() { + deps := make(map[string]*Package) + var q []*Package + q = append(q, p.Internal.Imports...) + for i := 0; i < len(q); i++ { + p1 := q[i] + path := p1.ImportPath + // The same import path could produce an error or not, + // depending on what tries to import it. + // Prefer to record entries with errors, so we can report them. + p0 := deps[path] + if p0 == nil || p1.Error != nil && (p0.Error == nil || len(p0.Error.ImportStack) > len(p1.Error.ImportStack)) { + deps[path] = p1 + for _, p2 := range p1.Internal.Imports { + if deps[p2.ImportPath] != p2 { + q = append(q, p2) + } + } + } + } + + p.Deps = make([]string, 0, len(deps)) + for dep := range deps { + p.Deps = append(p.Deps, dep) + } + sort.Strings(p.Deps) + for _, dep := range p.Deps { + p1 := deps[dep] + if p1 == nil { + panic("impossible: missing entry in package cache for " + dep + " imported by " + p.ImportPath) + } + if p1.Error != nil { + p.DepsErrors = append(p.DepsErrors, p1.Error) + } + } +} + +// SafeArg reports whether arg is a "safe" command-line argument, +// meaning that when it appears in a command-line, it probably +// doesn't have some special meaning other than its own name. +// Obviously args beginning with - are not safe (they look like flags). +// Less obviously, args beginning with @ are not safe (they look like +// GNU binutils flagfile specifiers, sometimes called "response files"). +// To be conservative, we reject almost any arg beginning with non-alphanumeric ASCII. +// We accept leading . _ and / as likely in file system paths. +// There is a copy of this function in cmd/compile/internal/gc/noder.go. +func SafeArg(name string) bool { + if name == "" { + return false + } + c := name[0] + return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '.' || c == '_' || c == '/' || c >= utf8.RuneSelf +} + +// LinkerDeps returns the list of linker-induced dependencies for main package p. +func LinkerDeps(p *Package) []string { + // Everything links runtime. + deps := []string{"runtime"} + + // External linking mode forces an import of runtime/cgo. + if externalLinkingForced(p) && cfg.BuildContext.Compiler != "gccgo" { + deps = append(deps, "runtime/cgo") + } + // On ARM with GOARM=5, it forces an import of math, for soft floating point. + if cfg.Goarch == "arm" { + deps = append(deps, "math") + } + // Using the race detector forces an import of runtime/race. + if cfg.BuildRace { + deps = append(deps, "runtime/race") + } + // Using memory sanitizer forces an import of runtime/msan. + if cfg.BuildMSan { + deps = append(deps, "runtime/msan") + } + + return deps +} + +// externalLinkingForced reports whether external linking is being +// forced even for programs that do not use cgo. +func externalLinkingForced(p *Package) bool { + if !cfg.BuildContext.CgoEnabled { + return false + } + + // Some targets must use external linking even inside GOROOT. + switch cfg.BuildContext.GOOS { + case "android": + if cfg.BuildContext.GOARCH != "arm64" { + return true + } + case "ios": + return true + } + + // Currently build modes c-shared, pie (on systems that do not + // support PIE with internal linking mode (currently all + // systems: issue #18968)), plugin, and -linkshared force + // external linking mode, as of course does + // -ldflags=-linkmode=external. External linking mode forces + // an import of runtime/cgo. + // If there are multiple -linkmode options, the last one wins. + pieCgo := cfg.BuildBuildmode == "pie" && !sys.InternalLinkPIESupported(cfg.BuildContext.GOOS, cfg.BuildContext.GOARCH) + linkmodeExternal := false + if p != nil { + ldflags := BuildLdflags.For(p) + for i := len(ldflags) - 1; i >= 0; i-- { + a := ldflags[i] + if a == "-linkmode=external" || + a == "-linkmode" && i+1 < len(ldflags) && ldflags[i+1] == "external" { + linkmodeExternal = true + break + } else if a == "-linkmode=internal" || + a == "-linkmode" && i+1 < len(ldflags) && ldflags[i+1] == "internal" { + break + } + } + } + + return cfg.BuildBuildmode == "c-shared" || cfg.BuildBuildmode == "plugin" || pieCgo || cfg.BuildLinkshared || linkmodeExternal +} + +// mkAbs rewrites list, which must be paths relative to p.Dir, +// into a sorted list of absolute paths. It edits list in place but for +// convenience also returns list back to its caller. +func (p *Package) mkAbs(list []string) []string { + for i, f := range list { + list[i] = filepath.Join(p.Dir, f) + } + sort.Strings(list) + return list +} + +// InternalGoFiles returns the list of Go files being built for the package, +// using absolute paths. +func (p *Package) InternalGoFiles() []string { + return p.mkAbs(str.StringList(p.GoFiles, p.CgoFiles, p.TestGoFiles)) +} + +// InternalXGoFiles returns the list of Go files being built for the XTest package, +// using absolute paths. +func (p *Package) InternalXGoFiles() []string { + return p.mkAbs(p.XTestGoFiles) +} + +// InternalGoFiles returns the list of all Go files possibly relevant for the package, +// using absolute paths. "Possibly relevant" means that files are not excluded +// due to build tags, but files with names beginning with . or _ are still excluded. +func (p *Package) InternalAllGoFiles() []string { + return p.mkAbs(str.StringList(p.IgnoredGoFiles, p.GoFiles, p.CgoFiles, p.TestGoFiles, p.XTestGoFiles)) +} + +// usesSwig reports whether the package needs to run SWIG. +func (p *Package) UsesSwig() bool { + return len(p.SwigFiles) > 0 || len(p.SwigCXXFiles) > 0 +} + +// usesCgo reports whether the package needs to run cgo +func (p *Package) UsesCgo() bool { + return len(p.CgoFiles) > 0 +} + +// PackageList returns the list of packages in the dag rooted at roots +// as visited in a depth-first post-order traversal. +func PackageList(roots []*Package) []*Package { + seen := map[*Package]bool{} + all := []*Package{} + var walk func(*Package) + walk = func(p *Package) { + if seen[p] { + return + } + seen[p] = true + for _, p1 := range p.Internal.Imports { + walk(p1) + } + all = append(all, p) + } + for _, root := range roots { + walk(root) + } + return all +} + +// TestPackageList returns the list of packages in the dag rooted at roots +// as visited in a depth-first post-order traversal, including the test +// imports of the roots. This ignores errors in test packages. +func TestPackageList(ctx context.Context, roots []*Package) []*Package { + seen := map[*Package]bool{} + all := []*Package{} + var walk func(*Package) + walk = func(p *Package) { + if seen[p] { + return + } + seen[p] = true + for _, p1 := range p.Internal.Imports { + walk(p1) + } + all = append(all, p) + } + walkTest := func(root *Package, path string) { + var stk ImportStack + p1 := LoadImport(ctx, path, root.Dir, root, &stk, root.Internal.Build.TestImportPos[path], ResolveImport) + if p1.Error == nil { + walk(p1) + } + } + for _, root := range roots { + walk(root) + for _, path := range root.TestImports { + walkTest(root, path) + } + for _, path := range root.XTestImports { + walkTest(root, path) + } + } + return all +} + +// LoadImportWithFlags loads the package with the given import path and +// sets tool flags on that package. This function is useful loading implicit +// dependencies (like sync/atomic for coverage). +// TODO(jayconrod): delete this function and set flags automatically +// in LoadImport instead. +func LoadImportWithFlags(path, srcDir string, parent *Package, stk *ImportStack, importPos []token.Position, mode int) *Package { + p := LoadImport(context.TODO(), path, srcDir, parent, stk, importPos, mode) + setToolFlags(p) + return p +} + +// ModResolveTests indicates whether calls to the module loader should also +// resolve test dependencies of the requested packages. +// +// If ModResolveTests is true, then the module loader needs to resolve test +// dependencies at the same time as packages; otherwise, the test dependencies +// of those packages could be missing, and resolving those missing dependencies +// could change the selected versions of modules that provide other packages. +// +// TODO(#40775): Change this from a global variable to an explicit function +// argument where needed. +var ModResolveTests bool + +// PackagesAndErrors returns the packages named by the command line arguments +// 'patterns'. If a named package cannot be loaded, PackagesAndErrors returns +// a *Package with the Error field describing the failure. If errors are found +// loading imported packages, the DepsErrors field is set. The Incomplete field +// may be set as well. +// +// To obtain a flat list of packages, use PackageList. +// To report errors loading packages, use ReportPackageErrors. +func PackagesAndErrors(ctx context.Context, patterns []string) []*Package { + ctx, span := trace.StartSpan(ctx, "load.PackagesAndErrors") + defer span.Done() + + for _, p := range patterns { + // Listing is only supported with all patterns referring to either: + // - Files that are part of the same directory. + // - Explicit package paths or patterns. + if strings.HasSuffix(p, ".go") { + // We need to test whether the path is an actual Go file and not a + // package path or pattern ending in '.go' (see golang.org/issue/34653). + if fi, err := fsys.Stat(p); err == nil && !fi.IsDir() { + return []*Package{GoFilesPackage(ctx, patterns)} + } + } + } + + var matches []*search.Match + if modload.Init(); cfg.ModulesEnabled { + loadOpts := modload.PackageOpts{ + ResolveMissingImports: true, + LoadTests: ModResolveTests, + SilenceErrors: true, + } + matches, _ = modload.LoadPackages(ctx, loadOpts, patterns...) + } else { + matches = search.ImportPaths(patterns) + } + + var ( + pkgs []*Package + stk ImportStack + seenPkg = make(map[*Package]bool) + ) + + pre := newPreload() + defer pre.flush() + pre.preloadMatches(matches) + + for _, m := range matches { + for _, pkg := range m.Pkgs { + if pkg == "" { + panic(fmt.Sprintf("ImportPaths returned empty package for pattern %s", m.Pattern())) + } + p := loadImport(ctx, pre, pkg, base.Cwd, nil, &stk, nil, 0) + p.Match = append(p.Match, m.Pattern()) + p.Internal.CmdlinePkg = true + if m.IsLiteral() { + // Note: do not set = m.IsLiteral unconditionally + // because maybe we'll see p matching both + // a literal and also a non-literal pattern. + p.Internal.CmdlinePkgLiteral = true + } + if seenPkg[p] { + continue + } + seenPkg[p] = true + pkgs = append(pkgs, p) + } + + if len(m.Errs) > 0 { + // In addition to any packages that were actually resolved from the + // pattern, there was some error in resolving the pattern itself. + // Report it as a synthetic package. + p := new(Package) + p.ImportPath = m.Pattern() + // Pass an empty ImportStack and nil importPos: the error arose from a pattern, not an import. + var stk ImportStack + var importPos []token.Position + p.setLoadPackageDataError(m.Errs[0], m.Pattern(), &stk, importPos) + p.Incomplete = true + p.Match = append(p.Match, m.Pattern()) + p.Internal.CmdlinePkg = true + if m.IsLiteral() { + p.Internal.CmdlinePkgLiteral = true + } + pkgs = append(pkgs, p) + } + } + + // Now that CmdlinePkg is set correctly, + // compute the effective flags for all loaded packages + // (not just the ones matching the patterns but also + // their dependencies). + setToolFlags(pkgs...) + + return pkgs +} + +// CheckPackageErrors prints errors encountered loading pkgs and their +// dependencies, then exits with a non-zero status if any errors were found. +func CheckPackageErrors(pkgs []*Package) { + printed := map[*PackageError]bool{} + for _, pkg := range pkgs { + if pkg.Error != nil { + base.Errorf("%v", pkg.Error) + printed[pkg.Error] = true + } + for _, err := range pkg.DepsErrors { + // Since these are errors in dependencies, + // the same error might show up multiple times, + // once in each package that depends on it. + // Only print each once. + if !printed[err] { + printed[err] = true + base.Errorf("%v", err) + } + } + } + base.ExitIfErrors() + + // Check for duplicate loads of the same package. + // That should be impossible, but if it does happen then + // we end up trying to build the same package twice, + // usually in parallel overwriting the same files, + // which doesn't work very well. + seen := map[string]bool{} + reported := map[string]bool{} + for _, pkg := range PackageList(pkgs) { + if seen[pkg.ImportPath] && !reported[pkg.ImportPath] { + reported[pkg.ImportPath] = true + base.Errorf("internal error: duplicate loads of %s", pkg.ImportPath) + } + seen[pkg.ImportPath] = true + } + base.ExitIfErrors() +} + +func setToolFlags(pkgs ...*Package) { + for _, p := range PackageList(pkgs) { + p.Internal.Asmflags = BuildAsmflags.For(p) + p.Internal.Gcflags = BuildGcflags.For(p) + p.Internal.Ldflags = BuildLdflags.For(p) + p.Internal.Gccgoflags = BuildGccgoflags.For(p) + } +} + +// GoFilesPackage creates a package for building a collection of Go files +// (typically named on the command line). The target is named p.a for +// package p or named after the first Go file for package main. +func GoFilesPackage(ctx context.Context, gofiles []string) *Package { + modload.Init() + + for _, f := range gofiles { + if !strings.HasSuffix(f, ".go") { + pkg := new(Package) + pkg.Internal.Local = true + pkg.Internal.CmdlineFiles = true + pkg.Name = f + pkg.Error = &PackageError{ + Err: fmt.Errorf("named files must be .go files: %s", pkg.Name), + } + return pkg + } + } + + var stk ImportStack + ctxt := cfg.BuildContext + ctxt.UseAllFiles = true + + // Synthesize fake "directory" that only shows the named files, + // to make it look like this is a standard package or + // command directory. So that local imports resolve + // consistently, the files must all be in the same directory. + var dirent []fs.FileInfo + var dir string + for _, file := range gofiles { + fi, err := fsys.Stat(file) + if err != nil { + base.Fatalf("%s", err) + } + if fi.IsDir() { + base.Fatalf("%s is a directory, should be a Go file", file) + } + dir1, _ := filepath.Split(file) + if dir1 == "" { + dir1 = "./" + } + if dir == "" { + dir = dir1 + } else if dir != dir1 { + base.Fatalf("named files must all be in one directory; have %s and %s", dir, dir1) + } + dirent = append(dirent, fi) + } + ctxt.ReadDir = func(string) ([]fs.FileInfo, error) { return dirent, nil } + + if cfg.ModulesEnabled { + modload.ImportFromFiles(ctx, gofiles) + } + + var err error + if dir == "" { + dir = base.Cwd + } + dir, err = filepath.Abs(dir) + if err != nil { + base.Fatalf("%s", err) + } + + bp, err := ctxt.ImportDir(dir, 0) + pkg := new(Package) + pkg.Internal.Local = true + pkg.Internal.CmdlineFiles = true + pkg.load(ctx, "command-line-arguments", &stk, nil, bp, err) + pkg.Internal.LocalPrefix = dirToImportPath(dir) + pkg.ImportPath = "command-line-arguments" + pkg.Target = "" + pkg.Match = gofiles + + if pkg.Name == "main" { + exe := pkg.DefaultExecName() + cfg.ExeSuffix + + if cfg.GOBIN != "" { + pkg.Target = filepath.Join(cfg.GOBIN, exe) + } else if cfg.ModulesEnabled { + pkg.Target = filepath.Join(modload.BinDir(), exe) + } + } + + setToolFlags(pkg) + + return pkg +} |