| // Copyright 2009 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 noder |
| |
| import ( |
| "errors" |
| "fmt" |
| "internal/buildcfg" |
| "internal/exportdata" |
| "internal/pkgbits" |
| "os" |
| pathpkg "path" |
| "runtime" |
| "strings" |
| "unicode" |
| "unicode/utf8" |
| |
| "cmd/compile/internal/base" |
| "cmd/compile/internal/importer" |
| "cmd/compile/internal/ir" |
| "cmd/compile/internal/typecheck" |
| "cmd/compile/internal/types" |
| "cmd/compile/internal/types2" |
| "cmd/internal/bio" |
| "cmd/internal/goobj" |
| "cmd/internal/objabi" |
| ) |
| |
| type gcimports struct { |
| ctxt *types2.Context |
| packages map[string]*types2.Package |
| } |
| |
| func (m *gcimports) Import(path string) (*types2.Package, error) { |
| return m.ImportFrom(path, "" /* no vendoring */, 0) |
| } |
| |
| func (m *gcimports) ImportFrom(path, srcDir string, mode types2.ImportMode) (*types2.Package, error) { |
| if mode != 0 { |
| panic("mode must be 0") |
| } |
| |
| _, pkg, err := readImportFile(path, typecheck.Target, m.ctxt, m.packages) |
| return pkg, err |
| } |
| |
| func isDriveLetter(b byte) bool { |
| return 'a' <= b && b <= 'z' || 'A' <= b && b <= 'Z' |
| } |
| |
| // is this path a local name? begins with ./ or ../ or / |
| func islocalname(name string) bool { |
| return strings.HasPrefix(name, "/") || |
| runtime.GOOS == "windows" && len(name) >= 3 && isDriveLetter(name[0]) && name[1] == ':' && name[2] == '/' || |
| strings.HasPrefix(name, "./") || name == "." || |
| strings.HasPrefix(name, "../") || name == ".." |
| } |
| |
| func openPackage(path string) (*os.File, error) { |
| if islocalname(path) { |
| if base.Flag.NoLocalImports { |
| return nil, errors.New("local imports disallowed") |
| } |
| |
| if base.Flag.Cfg.PackageFile != nil { |
| return os.Open(base.Flag.Cfg.PackageFile[path]) |
| } |
| |
| // try .a before .o. important for building libraries: |
| // if there is an array.o in the array.a library, |
| // want to find all of array.a, not just array.o. |
| if file, err := os.Open(fmt.Sprintf("%s.a", path)); err == nil { |
| return file, nil |
| } |
| if file, err := os.Open(fmt.Sprintf("%s.o", path)); err == nil { |
| return file, nil |
| } |
| return nil, errors.New("file not found") |
| } |
| |
| // local imports should be canonicalized already. |
| // don't want to see "encoding/../encoding/base64" |
| // as different from "encoding/base64". |
| if q := pathpkg.Clean(path); q != path { |
| return nil, fmt.Errorf("non-canonical import path %q (should be %q)", path, q) |
| } |
| |
| if base.Flag.Cfg.PackageFile != nil { |
| return os.Open(base.Flag.Cfg.PackageFile[path]) |
| } |
| |
| for _, dir := range base.Flag.Cfg.ImportDirs { |
| if file, err := os.Open(fmt.Sprintf("%s/%s.a", dir, path)); err == nil { |
| return file, nil |
| } |
| if file, err := os.Open(fmt.Sprintf("%s/%s.o", dir, path)); err == nil { |
| return file, nil |
| } |
| } |
| |
| if buildcfg.GOROOT != "" { |
| suffix := "" |
| if base.Flag.InstallSuffix != "" { |
| suffix = "_" + base.Flag.InstallSuffix |
| } else if base.Flag.Race { |
| suffix = "_race" |
| } else if base.Flag.MSan { |
| suffix = "_msan" |
| } else if base.Flag.ASan { |
| suffix = "_asan" |
| } |
| |
| if file, err := os.Open(fmt.Sprintf("%s/pkg/%s_%s%s/%s.a", buildcfg.GOROOT, buildcfg.GOOS, buildcfg.GOARCH, suffix, path)); err == nil { |
| return file, nil |
| } |
| if file, err := os.Open(fmt.Sprintf("%s/pkg/%s_%s%s/%s.o", buildcfg.GOROOT, buildcfg.GOOS, buildcfg.GOARCH, suffix, path)); err == nil { |
| return file, nil |
| } |
| } |
| return nil, errors.New("file not found") |
| } |
| |
| // resolveImportPath resolves an import path as it appears in a Go |
| // source file to the package's full path. |
| func resolveImportPath(path string) (string, error) { |
| // The package name main is no longer reserved, |
| // but we reserve the import path "main" to identify |
| // the main package, just as we reserve the import |
| // path "math" to identify the standard math package. |
| if path == "main" { |
| return "", errors.New("cannot import \"main\"") |
| } |
| |
| if base.Ctxt.Pkgpath == "" { |
| panic("missing pkgpath") |
| } |
| if path == base.Ctxt.Pkgpath { |
| return "", fmt.Errorf("import %q while compiling that package (import cycle)", path) |
| } |
| |
| if mapped, ok := base.Flag.Cfg.ImportMap[path]; ok { |
| path = mapped |
| } |
| |
| if islocalname(path) { |
| if path[0] == '/' { |
| return "", errors.New("import path cannot be absolute path") |
| } |
| |
| prefix := base.Flag.D |
| if prefix == "" { |
| // Questionable, but when -D isn't specified, historically we |
| // resolve local import paths relative to the directory the |
| // compiler's current directory, not the respective source |
| // file's directory. |
| prefix = base.Ctxt.Pathname |
| } |
| path = pathpkg.Join(prefix, path) |
| |
| if err := checkImportPath(path, true); err != nil { |
| return "", err |
| } |
| } |
| |
| return path, nil |
| } |
| |
| // readImportFile reads the import file for the given package path and |
| // returns its types.Pkg representation. If packages is non-nil, the |
| // types2.Package representation is also returned. |
| func readImportFile(path string, target *ir.Package, env *types2.Context, packages map[string]*types2.Package) (pkg1 *types.Pkg, pkg2 *types2.Package, err error) { |
| path, err = resolveImportPath(path) |
| if err != nil { |
| return |
| } |
| |
| if path == "unsafe" { |
| pkg1, pkg2 = types.UnsafePkg, types2.Unsafe |
| |
| // TODO(mdempsky): Investigate if this actually matters. Why would |
| // the linker or runtime care whether a package imported unsafe? |
| if !pkg1.Direct { |
| pkg1.Direct = true |
| target.Imports = append(target.Imports, pkg1) |
| } |
| |
| return |
| } |
| |
| pkg1 = types.NewPkg(path, "") |
| if packages != nil { |
| pkg2 = packages[path] |
| assert(pkg1.Direct == (pkg2 != nil && pkg2.Complete())) |
| } |
| |
| if pkg1.Direct { |
| return |
| } |
| pkg1.Direct = true |
| target.Imports = append(target.Imports, pkg1) |
| |
| f, err := openPackage(path) |
| if err != nil { |
| return |
| } |
| defer f.Close() |
| |
| data, err := readExportData(f) |
| if err != nil { |
| return |
| } |
| |
| if base.Debug.Export != 0 { |
| fmt.Printf("importing %s (%s)\n", path, f.Name()) |
| } |
| |
| pr := pkgbits.NewPkgDecoder(pkg1.Path, data) |
| |
| // Read package descriptors for both types2 and compiler backend. |
| readPackage(newPkgReader(pr), pkg1, false) |
| pkg2 = importer.ReadPackage(env, packages, pr) |
| |
| err = addFingerprint(path, data) |
| return |
| } |
| |
| // readExportData returns the contents of GC-created unified export data. |
| func readExportData(f *os.File) (data string, err error) { |
| r := bio.NewReader(f) |
| |
| sz, err := exportdata.FindPackageDefinition(r.Reader) |
| if err != nil { |
| return |
| } |
| end := r.Offset() + int64(sz) |
| |
| abihdr, _, err := exportdata.ReadObjectHeaders(r.Reader) |
| if err != nil { |
| return |
| } |
| |
| if expect := objabi.HeaderString(); abihdr != expect { |
| err = fmt.Errorf("object is [%s] expected [%s]", abihdr, expect) |
| return |
| } |
| |
| _, err = exportdata.ReadExportDataHeader(r.Reader) |
| if err != nil { |
| return |
| } |
| |
| pos := r.Offset() |
| |
| // Map export data section (+ end-of-section marker) into memory |
| // as a single large string. This reduces heap fragmentation and |
| // allows returning individual substrings very efficiently. |
| var mapped string |
| mapped, err = base.MapFile(r.File(), pos, end-pos) |
| if err != nil { |
| return |
| } |
| |
| // check for end-of-section marker "\n$$\n" and remove it |
| const marker = "\n$$\n" |
| |
| var ok bool |
| data, ok = strings.CutSuffix(mapped, marker) |
| if !ok { |
| cutoff := data // include last 10 bytes in error message |
| if len(cutoff) >= 10 { |
| cutoff = cutoff[len(cutoff)-10:] |
| } |
| err = fmt.Errorf("expected $$ marker, but found %q (recompile package)", cutoff) |
| return |
| } |
| |
| return |
| } |
| |
| // addFingerprint reads the linker fingerprint included at the end of |
| // the exportdata. |
| func addFingerprint(path string, data string) error { |
| var fingerprint goobj.FingerprintType |
| |
| pos := len(data) - len(fingerprint) |
| if pos < 0 { |
| return fmt.Errorf("missing linker fingerprint in exportdata, but found %q", data) |
| } |
| buf := []byte(data[pos:]) |
| |
| copy(fingerprint[:], buf) |
| base.Ctxt.AddImport(path, fingerprint) |
| |
| return nil |
| } |
| |
| func checkImportPath(path string, allowSpace bool) error { |
| if path == "" { |
| return errors.New("import path is empty") |
| } |
| |
| if strings.Contains(path, "\x00") { |
| return errors.New("import path contains NUL") |
| } |
| |
| for ri := range base.ReservedImports { |
| if path == ri { |
| return fmt.Errorf("import path %q is reserved and cannot be used", path) |
| } |
| } |
| |
| for _, r := range path { |
| switch { |
| case r == utf8.RuneError: |
| return fmt.Errorf("import path contains invalid UTF-8 sequence: %q", path) |
| case r < 0x20 || r == 0x7f: |
| return fmt.Errorf("import path contains control character: %q", path) |
| case r == '\\': |
| return fmt.Errorf("import path contains backslash; use slash: %q", path) |
| case !allowSpace && unicode.IsSpace(r): |
| return fmt.Errorf("import path contains space character: %q", path) |
| case strings.ContainsRune("!\"#$%&'()*,:;<=>?[]^`{|}", r): |
| return fmt.Errorf("import path contains invalid character '%c': %q", r, path) |
| } |
| } |
| |
| return nil |
| } |
