diff options
Diffstat (limited to 'libgo/go/cmd/go/internal/module/module.go')
-rw-r--r-- | libgo/go/cmd/go/internal/module/module.go | 632 |
1 files changed, 0 insertions, 632 deletions
diff --git a/libgo/go/cmd/go/internal/module/module.go b/libgo/go/cmd/go/internal/module/module.go deleted file mode 100644 index 3e0baba15b3..00000000000 --- a/libgo/go/cmd/go/internal/module/module.go +++ /dev/null @@ -1,632 +0,0 @@ -// Copyright 2018 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 module defines the module.Version type -// along with support code. -package module - -// IMPORTANT NOTE -// -// This file essentially defines the set of valid import paths for the go command. -// There are many subtle considerations, including Unicode ambiguity, -// security, network, and file system representations. -// -// This file also defines the set of valid module path and version combinations, -// another topic with many subtle considerations. -// -// Changes to the semantics in this file require approval from rsc. - -import ( - "errors" - "fmt" - "sort" - "strings" - "unicode" - "unicode/utf8" - - "cmd/go/internal/semver" -) - -// A Version is defined by a module path and version pair. -type Version struct { - Path string - - // Version is usually a semantic version in canonical form. - // There are two exceptions to this general rule. - // First, the top-level target of a build has no specific version - // and uses Version = "". - // Second, during MVS calculations the version "none" is used - // to represent the decision to take no version of a given module. - Version string `json:",omitempty"` -} - -// A ModuleError indicates an error specific to a module. -type ModuleError struct { - Path string - Version string - Err error -} - -// VersionError returns a ModuleError derived from a Version and error. -func VersionError(v Version, err error) error { - return &ModuleError{ - Path: v.Path, - Version: v.Version, - Err: err, - } -} - -func (e *ModuleError) Error() string { - if v, ok := e.Err.(*InvalidVersionError); ok { - return fmt.Sprintf("%s@%s: invalid %s: %v", e.Path, v.Version, v.noun(), v.Err) - } - if e.Version != "" { - return fmt.Sprintf("%s@%s: %v", e.Path, e.Version, e.Err) - } - return fmt.Sprintf("module %s: %v", e.Path, e.Err) -} - -func (e *ModuleError) Unwrap() error { return e.Err } - -// An InvalidVersionError indicates an error specific to a version, with the -// module path unknown or specified externally. -// -// A ModuleError may wrap an InvalidVersionError, but an InvalidVersionError -// must not wrap a ModuleError. -type InvalidVersionError struct { - Version string - Pseudo bool - Err error -} - -// noun returns either "version" or "pseudo-version", depending on whether -// e.Version is a pseudo-version. -func (e *InvalidVersionError) noun() string { - if e.Pseudo { - return "pseudo-version" - } - return "version" -} - -func (e *InvalidVersionError) Error() string { - return fmt.Sprintf("%s %q invalid: %s", e.noun(), e.Version, e.Err) -} - -func (e *InvalidVersionError) Unwrap() error { return e.Err } - -// Check checks that a given module path, version pair is valid. -// In addition to the path being a valid module path -// and the version being a valid semantic version, -// the two must correspond. -// For example, the path "yaml/v2" only corresponds to -// semantic versions beginning with "v2.". -func Check(path, version string) error { - if err := CheckPath(path); err != nil { - return err - } - if !semver.IsValid(version) { - return &ModuleError{ - Path: path, - Err: &InvalidVersionError{Version: version, Err: errors.New("not a semantic version")}, - } - } - _, pathMajor, _ := SplitPathVersion(path) - if err := MatchPathMajor(version, pathMajor); err != nil { - return &ModuleError{Path: path, Err: err} - } - return nil -} - -// firstPathOK reports whether r can appear in the first element of a module path. -// The first element of the path must be an LDH domain name, at least for now. -// To avoid case ambiguity, the domain name must be entirely lower case. -func firstPathOK(r rune) bool { - return r == '-' || r == '.' || - '0' <= r && r <= '9' || - 'a' <= r && r <= 'z' -} - -// pathOK reports whether r can appear in an import path element. -// Paths can be ASCII letters, ASCII digits, and limited ASCII punctuation: + - . _ and ~. -// This matches what "go get" has historically recognized in import paths. -// TODO(rsc): We would like to allow Unicode letters, but that requires additional -// care in the safe encoding (see note below). -func pathOK(r rune) bool { - if r < utf8.RuneSelf { - return r == '+' || r == '-' || r == '.' || r == '_' || r == '~' || - '0' <= r && r <= '9' || - 'A' <= r && r <= 'Z' || - 'a' <= r && r <= 'z' - } - return false -} - -// fileNameOK reports whether r can appear in a file name. -// For now we allow all Unicode letters but otherwise limit to pathOK plus a few more punctuation characters. -// If we expand the set of allowed characters here, we have to -// work harder at detecting potential case-folding and normalization collisions. -// See note about "safe encoding" below. -func fileNameOK(r rune) bool { - if r < utf8.RuneSelf { - // Entire set of ASCII punctuation, from which we remove characters: - // ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~ - // We disallow some shell special characters: " ' * < > ? ` | - // (Note that some of those are disallowed by the Windows file system as well.) - // We also disallow path separators / : and \ (fileNameOK is only called on path element characters). - // We allow spaces (U+0020) in file names. - const allowed = "!#$%&()+,-.=@[]^_{}~ " - if '0' <= r && r <= '9' || 'A' <= r && r <= 'Z' || 'a' <= r && r <= 'z' { - return true - } - for i := 0; i < len(allowed); i++ { - if rune(allowed[i]) == r { - return true - } - } - return false - } - // It may be OK to add more ASCII punctuation here, but only carefully. - // For example Windows disallows < > \, and macOS disallows :, so we must not allow those. - return unicode.IsLetter(r) -} - -// CheckPath checks that a module path is valid. -func CheckPath(path string) error { - if err := checkPath(path, false); err != nil { - return fmt.Errorf("malformed module path %q: %v", path, err) - } - i := strings.Index(path, "/") - if i < 0 { - i = len(path) - } - if i == 0 { - return fmt.Errorf("malformed module path %q: leading slash", path) - } - if !strings.Contains(path[:i], ".") { - return fmt.Errorf("malformed module path %q: missing dot in first path element", path) - } - if path[0] == '-' { - return fmt.Errorf("malformed module path %q: leading dash in first path element", path) - } - for _, r := range path[:i] { - if !firstPathOK(r) { - return fmt.Errorf("malformed module path %q: invalid char %q in first path element", path, r) - } - } - if _, _, ok := SplitPathVersion(path); !ok { - return fmt.Errorf("malformed module path %q: invalid version", path) - } - return nil -} - -// CheckImportPath checks that an import path is valid. -func CheckImportPath(path string) error { - if err := checkPath(path, false); err != nil { - return fmt.Errorf("malformed import path %q: %v", path, err) - } - return nil -} - -// checkPath checks that a general path is valid. -// It returns an error describing why but not mentioning path. -// Because these checks apply to both module paths and import paths, -// the caller is expected to add the "malformed ___ path %q: " prefix. -// fileName indicates whether the final element of the path is a file name -// (as opposed to a directory name). -func checkPath(path string, fileName bool) error { - if !utf8.ValidString(path) { - return fmt.Errorf("invalid UTF-8") - } - if path == "" { - return fmt.Errorf("empty string") - } - if path[0] == '-' { - return fmt.Errorf("leading dash") - } - if strings.Contains(path, "..") { - return fmt.Errorf("double dot") - } - if strings.Contains(path, "//") { - return fmt.Errorf("double slash") - } - if path[len(path)-1] == '/' { - return fmt.Errorf("trailing slash") - } - elemStart := 0 - for i, r := range path { - if r == '/' { - if err := checkElem(path[elemStart:i], fileName); err != nil { - return err - } - elemStart = i + 1 - } - } - if err := checkElem(path[elemStart:], fileName); err != nil { - return err - } - return nil -} - -// checkElem checks whether an individual path element is valid. -// fileName indicates whether the element is a file name (not a directory name). -func checkElem(elem string, fileName bool) error { - if elem == "" { - return fmt.Errorf("empty path element") - } - if strings.Count(elem, ".") == len(elem) { - return fmt.Errorf("invalid path element %q", elem) - } - if elem[0] == '.' && !fileName { - return fmt.Errorf("leading dot in path element") - } - if elem[len(elem)-1] == '.' { - return fmt.Errorf("trailing dot in path element") - } - charOK := pathOK - if fileName { - charOK = fileNameOK - } - for _, r := range elem { - if !charOK(r) { - return fmt.Errorf("invalid char %q", r) - } - } - - // Windows disallows a bunch of path elements, sadly. - // See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file - short := elem - if i := strings.Index(short, "."); i >= 0 { - short = short[:i] - } - for _, bad := range badWindowsNames { - if strings.EqualFold(bad, short) { - return fmt.Errorf("%q disallowed as path element component on Windows", short) - } - } - return nil -} - -// CheckFilePath checks whether a slash-separated file path is valid. -func CheckFilePath(path string) error { - if err := checkPath(path, true); err != nil { - return fmt.Errorf("malformed file path %q: %v", path, err) - } - return nil -} - -// badWindowsNames are the reserved file path elements on Windows. -// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file -var badWindowsNames = []string{ - "CON", - "PRN", - "AUX", - "NUL", - "COM1", - "COM2", - "COM3", - "COM4", - "COM5", - "COM6", - "COM7", - "COM8", - "COM9", - "LPT1", - "LPT2", - "LPT3", - "LPT4", - "LPT5", - "LPT6", - "LPT7", - "LPT8", - "LPT9", -} - -// SplitPathVersion returns prefix and major version such that prefix+pathMajor == path -// and version is either empty or "/vN" for N >= 2. -// As a special case, gopkg.in paths are recognized directly; -// they require ".vN" instead of "/vN", and for all N, not just N >= 2. -func SplitPathVersion(path string) (prefix, pathMajor string, ok bool) { - if strings.HasPrefix(path, "gopkg.in/") { - return splitGopkgIn(path) - } - - i := len(path) - dot := false - for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9' || path[i-1] == '.') { - if path[i-1] == '.' { - dot = true - } - i-- - } - if i <= 1 || i == len(path) || path[i-1] != 'v' || path[i-2] != '/' { - return path, "", true - } - prefix, pathMajor = path[:i-2], path[i-2:] - if dot || len(pathMajor) <= 2 || pathMajor[2] == '0' || pathMajor == "/v1" { - return path, "", false - } - return prefix, pathMajor, true -} - -// splitGopkgIn is like SplitPathVersion but only for gopkg.in paths. -func splitGopkgIn(path string) (prefix, pathMajor string, ok bool) { - if !strings.HasPrefix(path, "gopkg.in/") { - return path, "", false - } - i := len(path) - if strings.HasSuffix(path, "-unstable") { - i -= len("-unstable") - } - for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9') { - i-- - } - if i <= 1 || path[i-1] != 'v' || path[i-2] != '.' { - // All gopkg.in paths must end in vN for some N. - return path, "", false - } - prefix, pathMajor = path[:i-2], path[i-2:] - if len(pathMajor) <= 2 || pathMajor[2] == '0' && pathMajor != ".v0" { - return path, "", false - } - return prefix, pathMajor, true -} - -// MatchPathMajor returns a non-nil error if the semantic version v -// does not match the path major version pathMajor. -func MatchPathMajor(v, pathMajor string) error { - if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") { - pathMajor = strings.TrimSuffix(pathMajor, "-unstable") - } - if strings.HasPrefix(v, "v0.0.0-") && pathMajor == ".v1" { - // Allow old bug in pseudo-versions that generated v0.0.0- pseudoversion for gopkg .v1. - // For example, gopkg.in/yaml.v2@v2.2.1's go.mod requires gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405. - return nil - } - m := semver.Major(v) - if pathMajor == "" { - if m == "v0" || m == "v1" || semver.Build(v) == "+incompatible" { - return nil - } - pathMajor = "v0 or v1" - } else if pathMajor[0] == '/' || pathMajor[0] == '.' { - if m == pathMajor[1:] { - return nil - } - pathMajor = pathMajor[1:] - } - return &InvalidVersionError{ - Version: v, - Err: fmt.Errorf("should be %s, not %s", pathMajor, semver.Major(v)), - } -} - -// PathMajorPrefix returns the major-version tag prefix implied by pathMajor. -// An empty PathMajorPrefix allows either v0 or v1. -// -// Note that MatchPathMajor may accept some versions that do not actually begin -// with this prefix: namely, it accepts a 'v0.0.0-' prefix for a '.v1' -// pathMajor, even though that pathMajor implies 'v1' tagging. -func PathMajorPrefix(pathMajor string) string { - if pathMajor == "" { - return "" - } - if pathMajor[0] != '/' && pathMajor[0] != '.' { - panic("pathMajor suffix " + pathMajor + " passed to PathMajorPrefix lacks separator") - } - if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") { - pathMajor = strings.TrimSuffix(pathMajor, "-unstable") - } - m := pathMajor[1:] - if m != semver.Major(m) { - panic("pathMajor suffix " + pathMajor + "passed to PathMajorPrefix is not a valid major version") - } - return m -} - -// CanonicalVersion returns the canonical form of the version string v. -// It is the same as semver.Canonical(v) except that it preserves the special build suffix "+incompatible". -func CanonicalVersion(v string) string { - cv := semver.Canonical(v) - if semver.Build(v) == "+incompatible" { - cv += "+incompatible" - } - return cv -} - -// Sort sorts the list by Path, breaking ties by comparing Versions. -func Sort(list []Version) { - sort.Slice(list, func(i, j int) bool { - mi := list[i] - mj := list[j] - if mi.Path != mj.Path { - return mi.Path < mj.Path - } - // To help go.sum formatting, allow version/file. - // Compare semver prefix by semver rules, - // file by string order. - vi := mi.Version - vj := mj.Version - var fi, fj string - if k := strings.Index(vi, "/"); k >= 0 { - vi, fi = vi[:k], vi[k:] - } - if k := strings.Index(vj, "/"); k >= 0 { - vj, fj = vj[:k], vj[k:] - } - if vi != vj { - return semver.Compare(vi, vj) < 0 - } - return fi < fj - }) -} - -// Safe encodings -// -// Module paths appear as substrings of file system paths -// (in the download cache) and of web server URLs in the proxy protocol. -// In general we cannot rely on file systems to be case-sensitive, -// nor can we rely on web servers, since they read from file systems. -// That is, we cannot rely on the file system to keep rsc.io/QUOTE -// and rsc.io/quote separate. Windows and macOS don't. -// Instead, we must never require two different casings of a file path. -// Because we want the download cache to match the proxy protocol, -// and because we want the proxy protocol to be possible to serve -// from a tree of static files (which might be stored on a case-insensitive -// file system), the proxy protocol must never require two different casings -// of a URL path either. -// -// One possibility would be to make the safe encoding be the lowercase -// hexadecimal encoding of the actual path bytes. This would avoid ever -// needing different casings of a file path, but it would be fairly illegible -// to most programmers when those paths appeared in the file system -// (including in file paths in compiler errors and stack traces) -// in web server logs, and so on. Instead, we want a safe encoding that -// leaves most paths unaltered. -// -// The safe encoding is this: -// replace every uppercase letter with an exclamation mark -// followed by the letter's lowercase equivalent. -// -// For example, -// github.com/Azure/azure-sdk-for-go -> github.com/!azure/azure-sdk-for-go. -// github.com/GoogleCloudPlatform/cloudsql-proxy -> github.com/!google!cloud!platform/cloudsql-proxy -// github.com/Sirupsen/logrus -> github.com/!sirupsen/logrus. -// -// Import paths that avoid upper-case letters are left unchanged. -// Note that because import paths are ASCII-only and avoid various -// problematic punctuation (like : < and >), the safe encoding is also ASCII-only -// and avoids the same problematic punctuation. -// -// Import paths have never allowed exclamation marks, so there is no -// need to define how to encode a literal !. -// -// Although paths are disallowed from using Unicode (see pathOK above), -// the eventual plan is to allow Unicode letters as well, to assume that -// file systems and URLs are Unicode-safe (storing UTF-8), and apply -// the !-for-uppercase convention. Note however that not all runes that -// are different but case-fold equivalent are an upper/lower pair. -// For example, U+004B ('K'), U+006B ('k'), and U+212A ('K' for Kelvin) -// are considered to case-fold to each other. When we do add Unicode -// letters, we must not assume that upper/lower are the only case-equivalent pairs. -// Perhaps the Kelvin symbol would be disallowed entirely, for example. -// Or perhaps it would encode as "!!k", or perhaps as "(212A)". -// -// Also, it would be nice to allow Unicode marks as well as letters, -// but marks include combining marks, and then we must deal not -// only with case folding but also normalization: both U+00E9 ('é') -// and U+0065 U+0301 ('e' followed by combining acute accent) -// look the same on the page and are treated by some file systems -// as the same path. If we do allow Unicode marks in paths, there -// must be some kind of normalization to allow only one canonical -// encoding of any character used in an import path. - -// EncodePath returns the safe encoding of the given module path. -// It fails if the module path is invalid. -func EncodePath(path string) (encoding string, err error) { - if err := CheckPath(path); err != nil { - return "", err - } - - return encodeString(path) -} - -// EncodeVersion returns the safe encoding of the given module version. -// Versions are allowed to be in non-semver form but must be valid file names -// and not contain exclamation marks. -func EncodeVersion(v string) (encoding string, err error) { - if err := checkElem(v, true); err != nil || strings.Contains(v, "!") { - return "", &InvalidVersionError{ - Version: v, - Err: fmt.Errorf("disallowed version string"), - } - } - return encodeString(v) -} - -func encodeString(s string) (encoding string, err error) { - haveUpper := false - for _, r := range s { - if r == '!' || r >= utf8.RuneSelf { - // This should be disallowed by CheckPath, but diagnose anyway. - // The correctness of the encoding loop below depends on it. - return "", fmt.Errorf("internal error: inconsistency in EncodePath") - } - if 'A' <= r && r <= 'Z' { - haveUpper = true - } - } - - if !haveUpper { - return s, nil - } - - var buf []byte - for _, r := range s { - if 'A' <= r && r <= 'Z' { - buf = append(buf, '!', byte(r+'a'-'A')) - } else { - buf = append(buf, byte(r)) - } - } - return string(buf), nil -} - -// DecodePath returns the module path of the given safe encoding. -// It fails if the encoding is invalid or encodes an invalid path. -func DecodePath(encoding string) (path string, err error) { - path, ok := decodeString(encoding) - if !ok { - return "", fmt.Errorf("invalid module path encoding %q", encoding) - } - if err := CheckPath(path); err != nil { - return "", fmt.Errorf("invalid module path encoding %q: %v", encoding, err) - } - return path, nil -} - -// DecodeVersion returns the version string for the given safe encoding. -// It fails if the encoding is invalid or encodes an invalid version. -// Versions are allowed to be in non-semver form but must be valid file names -// and not contain exclamation marks. -func DecodeVersion(encoding string) (v string, err error) { - v, ok := decodeString(encoding) - if !ok { - return "", fmt.Errorf("invalid version encoding %q", encoding) - } - if err := checkElem(v, true); err != nil { - return "", fmt.Errorf("disallowed version string %q", v) - } - return v, nil -} - -func decodeString(encoding string) (string, bool) { - var buf []byte - - bang := false - for _, r := range encoding { - if r >= utf8.RuneSelf { - return "", false - } - if bang { - bang = false - if r < 'a' || 'z' < r { - return "", false - } - buf = append(buf, byte(r+'A'-'a')) - continue - } - if r == '!' { - bang = true - continue - } - if 'A' <= r && r <= 'Z' { - return "", false - } - buf = append(buf, byte(r)) - } - if bang { - return "", false - } - return string(buf), true -} |