diff options
Diffstat (limited to 'libgo/go/cmd/go/internal/search/search.go')
| -rw-r--r-- | libgo/go/cmd/go/internal/search/search.go | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/libgo/go/cmd/go/internal/search/search.go b/libgo/go/cmd/go/internal/search/search.go new file mode 100644 index 00000000000..60ae73696bb --- /dev/null +++ b/libgo/go/cmd/go/internal/search/search.go @@ -0,0 +1,505 @@ +// Copyright 2017 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 search + +import ( + "cmd/go/internal/base" + "cmd/go/internal/cfg" + "fmt" + "go/build" + "log" + "os" + "path" + "path/filepath" + "regexp" + "strings" +) + +// A Match represents the result of matching a single package pattern. +type Match struct { + Pattern string // the pattern itself + Literal bool // whether it is a literal (no wildcards) + Pkgs []string // matching packages (dirs or import paths) +} + +// MatchPackages returns all the packages that can be found +// under the $GOPATH directories and $GOROOT matching pattern. +// The pattern is either "all" (all packages), "std" (standard packages), +// "cmd" (standard commands), or a path including "...". +func MatchPackages(pattern string) *Match { + m := &Match{ + Pattern: pattern, + Literal: false, + } + match := func(string) bool { return true } + treeCanMatch := func(string) bool { return true } + if !IsMetaPackage(pattern) { + match = MatchPattern(pattern) + treeCanMatch = TreeCanMatchPattern(pattern) + } + + have := map[string]bool{ + "builtin": true, // ignore pseudo-package that exists only for documentation + } + if !cfg.BuildContext.CgoEnabled { + have["runtime/cgo"] = true // ignore during walk + } + + for _, src := range cfg.BuildContext.SrcDirs() { + if (pattern == "std" || pattern == "cmd") && src != cfg.GOROOTsrc { + continue + } + src = filepath.Clean(src) + string(filepath.Separator) + root := src + if pattern == "cmd" { + root += "cmd" + string(filepath.Separator) + } + filepath.Walk(root, func(path string, fi os.FileInfo, err error) error { + if err != nil || path == src { + return nil + } + + want := true + // Avoid .foo, _foo, and testdata directory trees. + _, elem := filepath.Split(path) + if strings.HasPrefix(elem, ".") || strings.HasPrefix(elem, "_") || elem == "testdata" { + want = false + } + + name := filepath.ToSlash(path[len(src):]) + if pattern == "std" && (!IsStandardImportPath(name) || name == "cmd") { + // The name "std" is only the standard library. + // If the name is cmd, it's the root of the command tree. + want = false + } + if !treeCanMatch(name) { + want = false + } + + if !fi.IsDir() { + if fi.Mode()&os.ModeSymlink != 0 && want { + if target, err := os.Stat(path); err == nil && target.IsDir() { + fmt.Fprintf(os.Stderr, "warning: ignoring symlink %s\n", path) + } + } + return nil + } + if !want { + return filepath.SkipDir + } + + if have[name] { + return nil + } + have[name] = true + if !match(name) { + return nil + } + pkg, err := cfg.BuildContext.ImportDir(path, 0) + if err != nil { + if _, noGo := err.(*build.NoGoError); noGo { + return nil + } + } + + // If we are expanding "cmd", skip main + // packages under cmd/vendor. At least as of + // March, 2017, there is one there for the + // vendored pprof tool. + if pattern == "cmd" && strings.HasPrefix(pkg.ImportPath, "cmd/vendor") && pkg.Name == "main" { + return nil + } + + m.Pkgs = append(m.Pkgs, name) + return nil + }) + } + return m +} + +var modRoot string + +func SetModRoot(dir string) { + modRoot = dir +} + +// MatchPackagesInFS is like allPackages but is passed a pattern +// beginning ./ or ../, meaning it should scan the tree rooted +// at the given directory. There are ... in the pattern too. +// (See go help packages for pattern syntax.) +func MatchPackagesInFS(pattern string) *Match { + m := &Match{ + Pattern: pattern, + Literal: false, + } + + // Find directory to begin the scan. + // Could be smarter but this one optimization + // is enough for now, since ... is usually at the + // end of a path. + i := strings.Index(pattern, "...") + dir, _ := path.Split(pattern[:i]) + + // pattern begins with ./ or ../. + // path.Clean will discard the ./ but not the ../. + // We need to preserve the ./ for pattern matching + // and in the returned import paths. + prefix := "" + if strings.HasPrefix(pattern, "./") { + prefix = "./" + } + match := MatchPattern(pattern) + + if modRoot != "" { + abs, err := filepath.Abs(dir) + if err != nil { + base.Fatalf("go: %v", err) + } + if !hasFilepathPrefix(abs, modRoot) { + base.Fatalf("go: pattern %s refers to dir %s, outside module root %s", pattern, abs, modRoot) + return nil + } + } + + filepath.Walk(dir, func(path string, fi os.FileInfo, err error) error { + if err != nil || !fi.IsDir() { + return nil + } + top := false + if path == dir { + // filepath.Walk starts at dir and recurses. For the recursive case, + // the path is the result of filepath.Join, which calls filepath.Clean. + // The initial case is not Cleaned, though, so we do this explicitly. + // + // This converts a path like "./io/" to "io". Without this step, running + // "cd $GOROOT/src; go list ./io/..." would incorrectly skip the io + // package, because prepending the prefix "./" to the unclean path would + // result in "././io", and match("././io") returns false. + top = true + path = filepath.Clean(path) + } + + // Avoid .foo, _foo, and testdata directory trees, but do not avoid "." or "..". + _, elem := filepath.Split(path) + dot := strings.HasPrefix(elem, ".") && elem != "." && elem != ".." + if dot || strings.HasPrefix(elem, "_") || elem == "testdata" { + return filepath.SkipDir + } + + if !top && cfg.ModulesEnabled { + // Ignore other modules found in subdirectories. + if _, err := os.Stat(filepath.Join(path, "go.mod")); err == nil { + return filepath.SkipDir + } + } + + name := prefix + filepath.ToSlash(path) + if !match(name) { + return nil + } + + // We keep the directory if we can import it, or if we can't import it + // due to invalid Go source files. This means that directories containing + // parse errors will be built (and fail) instead of being silently skipped + // as not matching the pattern. Go 1.5 and earlier skipped, but that + // behavior means people miss serious mistakes. + // See golang.org/issue/11407. + if p, err := cfg.BuildContext.ImportDir(path, 0); err != nil && (p == nil || len(p.InvalidGoFiles) == 0) { + if _, noGo := err.(*build.NoGoError); !noGo { + log.Print(err) + } + return nil + } + m.Pkgs = append(m.Pkgs, name) + return nil + }) + return m +} + +// TreeCanMatchPattern(pattern)(name) reports whether +// name or children of name can possibly match pattern. +// Pattern is the same limited glob accepted by matchPattern. +func TreeCanMatchPattern(pattern string) func(name string) bool { + wildCard := false + if i := strings.Index(pattern, "..."); i >= 0 { + wildCard = true + pattern = pattern[:i] + } + return func(name string) bool { + return len(name) <= len(pattern) && hasPathPrefix(pattern, name) || + wildCard && strings.HasPrefix(name, pattern) + } +} + +// MatchPattern(pattern)(name) reports whether +// name matches pattern. Pattern is a limited glob +// pattern in which '...' means 'any string' and there +// is no other special syntax. +// Unfortunately, there are two special cases. Quoting "go help packages": +// +// First, /... at the end of the pattern can match an empty string, +// so that net/... matches both net and packages in its subdirectories, like net/http. +// Second, any slash-separted pattern element containing a wildcard never +// participates in a match of the "vendor" element in the path of a vendored +// package, so that ./... does not match packages in subdirectories of +// ./vendor or ./mycode/vendor, but ./vendor/... and ./mycode/vendor/... do. +// Note, however, that a directory named vendor that itself contains code +// is not a vendored package: cmd/vendor would be a command named vendor, +// and the pattern cmd/... matches it. +func MatchPattern(pattern string) func(name string) bool { + // Convert pattern to regular expression. + // The strategy for the trailing /... is to nest it in an explicit ? expression. + // The strategy for the vendor exclusion is to change the unmatchable + // vendor strings to a disallowed code point (vendorChar) and to use + // "(anything but that codepoint)*" as the implementation of the ... wildcard. + // This is a bit complicated but the obvious alternative, + // namely a hand-written search like in most shell glob matchers, + // is too easy to make accidentally exponential. + // Using package regexp guarantees linear-time matching. + + const vendorChar = "\x00" + + if strings.Contains(pattern, vendorChar) { + return func(name string) bool { return false } + } + + re := regexp.QuoteMeta(pattern) + re = replaceVendor(re, vendorChar) + switch { + case strings.HasSuffix(re, `/`+vendorChar+`/\.\.\.`): + re = strings.TrimSuffix(re, `/`+vendorChar+`/\.\.\.`) + `(/vendor|/` + vendorChar + `/\.\.\.)` + case re == vendorChar+`/\.\.\.`: + re = `(/vendor|/` + vendorChar + `/\.\.\.)` + case strings.HasSuffix(re, `/\.\.\.`): + re = strings.TrimSuffix(re, `/\.\.\.`) + `(/\.\.\.)?` + } + re = strings.Replace(re, `\.\.\.`, `[^`+vendorChar+`]*`, -1) + + reg := regexp.MustCompile(`^` + re + `$`) + + return func(name string) bool { + if strings.Contains(name, vendorChar) { + return false + } + return reg.MatchString(replaceVendor(name, vendorChar)) + } +} + +// replaceVendor returns the result of replacing +// non-trailing vendor path elements in x with repl. +func replaceVendor(x, repl string) string { + if !strings.Contains(x, "vendor") { + return x + } + elem := strings.Split(x, "/") + for i := 0; i < len(elem)-1; i++ { + if elem[i] == "vendor" { + elem[i] = repl + } + } + return strings.Join(elem, "/") +} + +// WarnUnmatched warns about patterns that didn't match any packages. +func WarnUnmatched(matches []*Match) { + for _, m := range matches { + if len(m.Pkgs) == 0 { + fmt.Fprintf(os.Stderr, "go: warning: %q matched no packages\n", m.Pattern) + } + } +} + +// ImportPaths returns the matching paths to use for the given command line. +// It calls ImportPathsQuiet and then WarnUnmatched. +func ImportPaths(patterns []string) []*Match { + matches := ImportPathsQuiet(patterns) + WarnUnmatched(matches) + return matches +} + +// ImportPathsQuiet is like ImportPaths but does not warn about patterns with no matches. +func ImportPathsQuiet(patterns []string) []*Match { + var out []*Match + for _, a := range CleanPatterns(patterns) { + if IsMetaPackage(a) { + out = append(out, MatchPackages(a)) + continue + } + if strings.Contains(a, "...") { + if build.IsLocalImport(a) { + out = append(out, MatchPackagesInFS(a)) + } else { + out = append(out, MatchPackages(a)) + } + continue + } + out = append(out, &Match{Pattern: a, Literal: true, Pkgs: []string{a}}) + } + return out +} + +// CleanPatterns returns the patterns to use for the given +// command line. It canonicalizes the patterns but does not +// evaluate any matches. +func CleanPatterns(patterns []string) []string { + if len(patterns) == 0 { + return []string{"."} + } + var out []string + for _, a := range patterns { + // Arguments are supposed to be import paths, but + // as a courtesy to Windows developers, rewrite \ to / + // in command-line arguments. Handles .\... and so on. + if filepath.Separator == '\\' { + a = strings.Replace(a, `\`, `/`, -1) + } + + // Put argument in canonical form, but preserve leading ./. + if strings.HasPrefix(a, "./") { + a = "./" + path.Clean(a) + if a == "./." { + a = "." + } + } else { + a = path.Clean(a) + } + out = append(out, a) + } + return out +} + +// IsMetaPackage checks if name is a reserved package name that expands to multiple packages. +func IsMetaPackage(name string) bool { + return name == "std" || name == "cmd" || name == "all" +} + +// hasPathPrefix reports whether the path s begins with the +// elements in prefix. +func hasPathPrefix(s, prefix string) bool { + switch { + default: + return false + case len(s) == len(prefix): + return s == prefix + case len(s) > len(prefix): + if prefix != "" && prefix[len(prefix)-1] == '/' { + return strings.HasPrefix(s, prefix) + } + return s[len(prefix)] == '/' && s[:len(prefix)] == prefix + } +} + +// hasFilepathPrefix reports whether the path s begins with the +// elements in prefix. +func hasFilepathPrefix(s, prefix string) bool { + switch { + default: + return false + case len(s) == len(prefix): + return s == prefix + case len(s) > len(prefix): + if prefix != "" && prefix[len(prefix)-1] == filepath.Separator { + return strings.HasPrefix(s, prefix) + } + return s[len(prefix)] == filepath.Separator && s[:len(prefix)] == prefix + } +} + +// IsStandardImportPath reports whether $GOROOT/src/path should be considered +// part of the standard distribution. For historical reasons we allow people to add +// their own code to $GOROOT instead of using $GOPATH, but we assume that +// code will start with a domain name (dot in the first element). +// +// Note that this function is meant to evaluate whether a directory found in GOROOT +// should be treated as part of the standard library. It should not be used to decide +// that a directory found in GOPATH should be rejected: directories in GOPATH +// need not have dots in the first element, and they just take their chances +// with future collisions in the standard library. +func IsStandardImportPath(path string) bool { + i := strings.Index(path, "/") + if i < 0 { + i = len(path) + } + elem := path[:i] + return !strings.Contains(elem, ".") +} + +// IsRelativePath reports whether pattern should be interpreted as a directory +// path relative to the current directory, as opposed to a pattern matching +// import paths. +func IsRelativePath(pattern string) bool { + return strings.HasPrefix(pattern, "./") || strings.HasPrefix(pattern, "../") || pattern == "." || pattern == ".." +} + +// InDir checks whether path is in the file tree rooted at dir. +// If so, InDir returns an equivalent path relative to dir. +// If not, InDir returns an empty string. +// InDir makes some effort to succeed even in the presence of symbolic links. +// TODO(rsc): Replace internal/test.inDir with a call to this function for Go 1.12. +func InDir(path, dir string) string { + if rel := inDirLex(path, dir); rel != "" { + return rel + } + xpath, err := filepath.EvalSymlinks(path) + if err != nil || xpath == path { + xpath = "" + } else { + if rel := inDirLex(xpath, dir); rel != "" { + return rel + } + } + + xdir, err := filepath.EvalSymlinks(dir) + if err == nil && xdir != dir { + if rel := inDirLex(path, xdir); rel != "" { + return rel + } + if xpath != "" { + if rel := inDirLex(xpath, xdir); rel != "" { + return rel + } + } + } + return "" +} + +// inDirLex is like inDir but only checks the lexical form of the file names. +// It does not consider symbolic links. +// TODO(rsc): This is a copy of str.HasFilePathPrefix, modified to +// return the suffix. Most uses of str.HasFilePathPrefix should probably +// be calling InDir instead. +func inDirLex(path, dir string) string { + pv := strings.ToUpper(filepath.VolumeName(path)) + dv := strings.ToUpper(filepath.VolumeName(dir)) + path = path[len(pv):] + dir = dir[len(dv):] + switch { + default: + return "" + case pv != dv: + return "" + case len(path) == len(dir): + if path == dir { + return "." + } + return "" + case dir == "": + return path + case len(path) > len(dir): + if dir[len(dir)-1] == filepath.Separator { + if path[:len(dir)] == dir { + return path[len(dir):] + } + return "" + } + if path[len(dir)] == filepath.Separator && path[:len(dir)] == dir { + if len(path) == len(dir)+1 { + return "." + } + return path[len(dir)+1:] + } + return "" + } +} |