diff --git a/internal/mod/lazyregexp/lazyre.go b/internal/mod/lazyregexp/lazyre.go new file mode 100644 index 0000000000..7f524d2395 --- /dev/null +++ b/internal/mod/lazyregexp/lazyre.go @@ -0,0 +1,50 @@ +// 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 lazyregexp is a thin wrapper over regexp, allowing the use of global +// regexp variables without forcing them to be compiled at init. +package lazyregexp + +import ( + "os" + "regexp" + "strings" + "sync" +) + +// Regexp is a wrapper around regexp.Regexp, where the underlying regexp will be +// compiled the first time it is needed. +type Regexp struct { + str string + once sync.Once + rx *regexp.Regexp +} + +func (r *Regexp) re() *regexp.Regexp { + r.once.Do(r.build) + return r.rx +} + +func (r *Regexp) build() { + r.rx = regexp.MustCompile(r.str) + r.str = "" +} + +func (r *Regexp) MatchString(s string) bool { + return r.re().MatchString(s) +} + +var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test") + +// New creates a new lazy regexp, delaying the compiling work until it is first +// needed. If the code is being run as part of tests, the regexp compiling will +// happen immediately. +func New(str string) *Regexp { + lr := &Regexp{str: str} + if inTest { + // In tests, always compile the regexps early. + lr.re() + } + return lr +} diff --git a/internal/mod/modfile/read.go b/internal/mod/modfile/read.go new file mode 100644 index 0000000000..f49d553789 --- /dev/null +++ b/internal/mod/modfile/read.go @@ -0,0 +1,655 @@ +// 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 modfile + +import ( + "bytes" + "errors" + "fmt" + "os" + "strconv" + "strings" + "unicode" + "unicode/utf8" + + "golang.org/x/mod/modfile" +) + +// An input represents a single input file being parsed. +type input struct { + // Lexing state. + filename string // name of input file, for errors + complete []byte // entire input + remaining []byte // remaining input + tokenStart []byte // token being scanned to end of input + token token // next token to be returned by lex, peek + pos modfile.Position // current input position + comments []modfile.Comment // accumulated comments + + // Parser state. + file *modfile.FileSyntax // returned top-level syntax tree + parseErrors modfile.ErrorList // errors encountered during parsing + + // Comment assignment state. + pre []modfile.Expr // all expressions, in preorder traversal + post []modfile.Expr // all expressions, in postorder traversal +} + +func newInput(filename string, data []byte) *input { + return &input{ + filename: filename, + complete: data, + remaining: data, + pos: modfile.Position{Line: 1, LineRune: 1, Byte: 0}, + } +} + +// parse parses the input file. +func parse(file string, data []byte) (f *modfile.FileSyntax, err error) { + // The parser panics for both routine errors like syntax errors + // and for programmer bugs like array index errors. + // Turn both into error returns. Catching bug panics is + // especially important when processing many files. + in := newInput(file, data) + defer func() { + if e := recover(); e != nil && e != &in.parseErrors { + in.parseErrors = append(in.parseErrors, modfile.Error{ + Filename: in.filename, + Pos: in.pos, + Err: fmt.Errorf("internal error: %v", e), + }) + } + if err == nil && len(in.parseErrors) > 0 { + err = in.parseErrors + } + }() + + // Prime the lexer by reading in the first token. It will be available + // in the next peek() or lex() call. + in.readToken() + + // Invoke the parser. + in.parseFile() + if len(in.parseErrors) > 0 { + return nil, in.parseErrors + } + in.file.Name = in.filename + + // Assign comments to nearby syntax. + in.assignComments() + + return in.file, nil +} + +// Error is called to report an error. +// Error does not return: it panics. +func (in *input) Error(s string) { + in.parseErrors = append(in.parseErrors, modfile.Error{ + Filename: in.filename, + Pos: in.pos, + Err: errors.New(s), + }) + panic(&in.parseErrors) +} + +// eof reports whether the input has reached end of file. +func (in *input) eof() bool { + return len(in.remaining) == 0 +} + +// peekRune returns the next rune in the input without consuming it. +func (in *input) peekRune() int { + if len(in.remaining) == 0 { + return 0 + } + r, _ := utf8.DecodeRune(in.remaining) + return int(r) +} + +// peekPrefix reports whether the remaining input begins with the given prefix. +func (in *input) peekPrefix(prefix string) bool { + // This is like bytes.HasPrefix(in.remaining, []byte(prefix)) + // but without the allocation of the []byte copy of prefix. + for i := 0; i < len(prefix); i++ { + if i >= len(in.remaining) || in.remaining[i] != prefix[i] { + return false + } + } + return true +} + +// readRune consumes and returns the next rune in the input. +func (in *input) readRune() int { + if len(in.remaining) == 0 { + in.Error("internal lexer error: readRune at EOF") + } + r, size := utf8.DecodeRune(in.remaining) + in.remaining = in.remaining[size:] + if r == '\n' { + in.pos.Line++ + in.pos.LineRune = 1 + } else { + in.pos.LineRune++ + } + in.pos.Byte += size + return int(r) +} + +type token struct { + kind tokenKind + pos modfile.Position + endPos modfile.Position + text string +} + +type tokenKind int + +const ( + _EOF tokenKind = -(iota + 1) + _EOLCOMMENT + _IDENT + _STRING + _COMMENT + + // newlines and punctuation tokens are allowed as ASCII codes. +) + +func (k tokenKind) isComment() bool { + return k == _COMMENT || k == _EOLCOMMENT +} + +// isEOL returns whether a token terminates a line. +func (k tokenKind) isEOL() bool { + return k == _EOF || k == _EOLCOMMENT || k == '\n' +} + +// startToken marks the beginning of the next input token. +// It must be followed by a call to endToken, once the token's text has +// been consumed using readRune. +func (in *input) startToken() { + in.tokenStart = in.remaining + in.token.text = "" + in.token.pos = in.pos +} + +// endToken marks the end of an input token. +// It records the actual token string in tok.text. +// A single trailing newline (LF or CRLF) will be removed from comment tokens. +func (in *input) endToken(kind tokenKind) { + in.token.kind = kind + text := string(in.tokenStart[:len(in.tokenStart)-len(in.remaining)]) + if kind.isComment() { + if strings.HasSuffix(text, "\r\n") { + text = text[:len(text)-2] + } else { + text = strings.TrimSuffix(text, "\n") + } + } + in.token.text = text + in.token.endPos = in.pos +} + +// peek returns the kind of the the next token returned by lex. +func (in *input) peek() tokenKind { + return in.token.kind +} + +// lex is called from the parser to obtain the next input token. +func (in *input) lex() token { + tok := in.token + in.readToken() + return tok +} + +// readToken lexes the next token from the text and stores it in in.token. +func (in *input) readToken() { + // Skip past spaces, stopping at non-space or EOF. + for !in.eof() { + c := in.peekRune() + if c == ' ' || c == '\t' || c == '\r' { + in.readRune() + continue + } + + // Comment runs to end of line. + if in.peekPrefix("//") { + in.startToken() + + // Is this comment the only thing on its line? + // Find the last \n before this // and see if it's all + // spaces from there to here. + i := bytes.LastIndex(in.complete[:in.pos.Byte], []byte("\n")) + suffix := len(bytes.TrimSpace(in.complete[i+1:in.pos.Byte])) > 0 + in.readRune() + in.readRune() + + // Consume comment. + for len(in.remaining) > 0 && in.readRune() != '\n' { + } + + // If we are at top level (not in a statement), hand the comment to + // the parser as a _COMMENT token. The grammar is written + // to handle top-level comments itself. + if !suffix { + in.endToken(_COMMENT) + return + } + + // Otherwise, save comment for later attachment to syntax tree. + in.endToken(_EOLCOMMENT) + in.comments = append(in.comments, modfile.Comment{in.token.pos, in.token.text, suffix}) + return + } + + if in.peekPrefix("/*") { + in.Error("mod files must use // comments (not /* */ comments)") + } + + // Found non-space non-comment. + break + } + + // Found the beginning of the next token. + in.startToken() + + // End of file. + if in.eof() { + in.endToken(_EOF) + return + } + + // Punctuation tokens. + switch c := in.peekRune(); c { + case '\n', '(', ')', '[', ']', '{', '}', ',': + in.readRune() + in.endToken(tokenKind(c)) + return + + case '"', '`': // quoted string + quote := c + in.readRune() + for { + if in.eof() { + in.pos = in.token.pos + in.Error("unexpected EOF in string") + } + if in.peekRune() == '\n' { + in.Error("unexpected newline in string") + } + c := in.readRune() + if c == quote { + break + } + if c == '\\' && quote != '`' { + if in.eof() { + in.pos = in.token.pos + in.Error("unexpected EOF in string") + } + in.readRune() + } + } + in.endToken(_STRING) + return + } + + // Checked all punctuation. Must be identifier token. + if c := in.peekRune(); !isIdent(c) { + in.Error(fmt.Sprintf("unexpected input character %#q", c)) + } + + // Scan over identifier. + for isIdent(in.peekRune()) { + if in.peekPrefix("//") { + break + } + if in.peekPrefix("/*") { + in.Error("mod files must use // comments (not /* */ comments)") + } + in.readRune() + } + in.endToken(_IDENT) +} + +// isIdent reports whether c is an identifier rune. +// We treat most printable runes as identifier runes, except for a handful of +// ASCII punctuation characters. +func isIdent(c int) bool { + switch r := rune(c); r { + case ' ', '(', ')', '[', ']', '{', '}', ',': + return false + default: + return !unicode.IsSpace(r) && unicode.IsPrint(r) + } +} + +// Comment assignment. +// We build two lists of all subexpressions, preorder and postorder. +// The preorder list is ordered by start location, with outer expressions first. +// The postorder list is ordered by end location, with outer expressions last. +// We use the preorder list to assign each whole-line comment to the syntax +// immediately following it, and we use the postorder list to assign each +// end-of-line comment to the syntax immediately preceding it. + +// order walks the expression adding it and its subexpressions to the +// preorder and postorder lists. +func (in *input) order(x modfile.Expr) { + if x != nil { + in.pre = append(in.pre, x) + } + switch x := x.(type) { + default: + panic(fmt.Errorf("order: unexpected type %T", x)) + case nil: + // nothing + case *modfile.LParen, *modfile.RParen: + // nothing + case *modfile.CommentBlock: + // nothing + case *modfile.Line: + // nothing + case *modfile.FileSyntax: + for _, stmt := range x.Stmt { + in.order(stmt) + } + case *modfile.LineBlock: + in.order(&x.LParen) + for _, l := range x.Line { + in.order(l) + } + in.order(&x.RParen) + } + if x != nil { + in.post = append(in.post, x) + } +} + +// assignComments attaches comments to nearby syntax. +func (in *input) assignComments() { + const debug = false + + // Generate preorder and postorder lists. + in.order(in.file) + + // Split into whole-line comments and suffix comments. + var line, suffix []modfile.Comment + for _, com := range in.comments { + if com.Suffix { + suffix = append(suffix, com) + } else { + line = append(line, com) + } + } + + if debug { + for _, c := range line { + fmt.Fprintf(os.Stderr, "LINE %q :%d:%d #%d\n", c.Token, c.Start.Line, c.Start.LineRune, c.Start.Byte) + } + } + + // Assign line comments to syntax immediately following. + for _, x := range in.pre { + start, _ := x.Span() + if debug { + fmt.Fprintf(os.Stderr, "pre %T :%d:%d #%d\n", x, start.Line, start.LineRune, start.Byte) + } + xcom := x.Comment() + for len(line) > 0 && start.Byte >= line[0].Start.Byte { + if debug { + fmt.Fprintf(os.Stderr, "ASSIGN LINE %q #%d\n", line[0].Token, line[0].Start.Byte) + } + xcom.Before = append(xcom.Before, line[0]) + line = line[1:] + } + } + + // Remaining line comments go at end of file. + in.file.After = append(in.file.After, line...) + + if debug { + for _, c := range suffix { + fmt.Fprintf(os.Stderr, "SUFFIX %q :%d:%d #%d\n", c.Token, c.Start.Line, c.Start.LineRune, c.Start.Byte) + } + } + + // Assign suffix comments to syntax immediately before. + for i := len(in.post) - 1; i >= 0; i-- { + x := in.post[i] + + start, end := x.Span() + if debug { + fmt.Fprintf(os.Stderr, "post %T :%d:%d #%d :%d:%d #%d\n", x, start.Line, start.LineRune, start.Byte, end.Line, end.LineRune, end.Byte) + } + + // Do not assign suffix comments to end of line block or whole file. + // Instead assign them to the last element inside. + switch x.(type) { + case *modfile.FileSyntax: + continue + } + + // Do not assign suffix comments to something that starts + // on an earlier line, so that in + // + // x ( y + // z ) // comment + // + // we assign the comment to z and not to x ( ... ). + if start.Line != end.Line { + continue + } + xcom := x.Comment() + for len(suffix) > 0 && end.Byte <= suffix[len(suffix)-1].Start.Byte { + if debug { + fmt.Fprintf(os.Stderr, "ASSIGN SUFFIX %q #%d\n", suffix[len(suffix)-1].Token, suffix[len(suffix)-1].Start.Byte) + } + xcom.Suffix = append(xcom.Suffix, suffix[len(suffix)-1]) + suffix = suffix[:len(suffix)-1] + } + } + + // We assigned suffix comments in reverse. + // If multiple suffix comments were appended to the same + // expression node, they are now in reverse. Fix that. + for _, x := range in.post { + reverseComments(x.Comment().Suffix) + } + + // Remaining suffix comments go at beginning of file. + in.file.Before = append(in.file.Before, suffix...) +} + +// reverseComments reverses the []Comment list. +func reverseComments(list []modfile.Comment) { + for i, j := 0, len(list)-1; i < j; i, j = i+1, j-1 { + list[i], list[j] = list[j], list[i] + } +} + +func (in *input) parseFile() { + in.file = new(modfile.FileSyntax) + var cb *modfile.CommentBlock + for { + switch in.peek() { + case '\n': + in.lex() + if cb != nil { + in.file.Stmt = append(in.file.Stmt, cb) + cb = nil + } + case _COMMENT: + tok := in.lex() + if cb == nil { + cb = &modfile.CommentBlock{Start: tok.pos} + } + com := cb.Comment() + com.Before = append(com.Before, modfile.Comment{Start: tok.pos, Token: tok.text}) + case _EOF: + if cb != nil { + in.file.Stmt = append(in.file.Stmt, cb) + } + return + default: + in.parseStmt() + if cb != nil { + in.file.Stmt[len(in.file.Stmt)-1].Comment().Before = cb.Before + cb = nil + } + } + } +} + +func (in *input) parseStmt() { + tok := in.lex() + start := tok.pos + end := tok.endPos + tokens := []string{tok.text} + for { + tok := in.lex() + switch { + case tok.kind.isEOL(): + in.file.Stmt = append(in.file.Stmt, &modfile.Line{ + Start: start, + Token: tokens, + End: end, + }) + return + + case tok.kind == '(': + if next := in.peek(); next.isEOL() { + // Start of block: no more tokens on this line. + in.file.Stmt = append(in.file.Stmt, in.parseLineBlock(start, tokens, tok)) + return + } else if next == ')' { + rparen := in.lex() + if in.peek().isEOL() { + // Empty block. + in.lex() + in.file.Stmt = append(in.file.Stmt, &modfile.LineBlock{ + Start: start, + Token: tokens, + LParen: modfile.LParen{Pos: tok.pos}, + RParen: modfile.RParen{Pos: rparen.pos}, + }) + return + } + // '( )' in the middle of the line, not a block. + tokens = append(tokens, tok.text, rparen.text) + } else { + // '(' in the middle of the line, not a block. + tokens = append(tokens, tok.text) + } + + default: + tokens = append(tokens, tok.text) + end = tok.endPos + } + } +} + +func (in *input) parseLineBlock(start modfile.Position, token []string, lparen token) *modfile.LineBlock { + x := &modfile.LineBlock{ + Start: start, + Token: token, + LParen: modfile.LParen{Pos: lparen.pos}, + } + var comments []modfile.Comment + for { + switch in.peek() { + case _EOLCOMMENT: + // Suffix comment, will be attached later by assignComments. + in.lex() + case '\n': + // Blank line. Add an empty comment to preserve it. + in.lex() + if len(comments) == 0 && len(x.Line) > 0 || len(comments) > 0 && comments[len(comments)-1].Token != "" { + comments = append(comments, modfile.Comment{}) + } + case _COMMENT: + tok := in.lex() + comments = append(comments, modfile.Comment{Start: tok.pos, Token: tok.text}) + case _EOF: + in.Error(fmt.Sprintf("syntax error (unterminated block started at %s:%d:%d)", in.filename, x.Start.Line, x.Start.LineRune)) + case ')': + rparen := in.lex() + x.RParen.Before = comments + x.RParen.Pos = rparen.pos + if !in.peek().isEOL() { + in.Error("syntax error (expected newline after closing paren)") + } + in.lex() + return x + default: + l := in.parseLine() + x.Line = append(x.Line, l) + l.Comment().Before = comments + comments = nil + } + } +} + +func (in *input) parseLine() *modfile.Line { + tok := in.lex() + if tok.kind.isEOL() { + in.Error("internal parse error: parseLine at end of line") + } + start := tok.pos + end := tok.endPos + tokens := []string{tok.text} + for { + tok := in.lex() + if tok.kind.isEOL() { + return &modfile.Line{ + Start: start, + Token: tokens, + End: end, + InBlock: true, + } + } + tokens = append(tokens, tok.text) + end = tok.endPos + } +} + +var ( + slashSlash = []byte("//") + moduleStr = []byte("module") +) + +// ModulePath returns the module path from the gomod file text. +// If it cannot find a module path, it returns an empty string. +// It is tolerant of unrelated problems in the go.mod file. +func ModulePath(mod []byte) string { + for len(mod) > 0 { + line := mod + mod = nil + if i := bytes.IndexByte(line, '\n'); i >= 0 { + line, mod = line[:i], line[i+1:] + } + if i := bytes.Index(line, slashSlash); i >= 0 { + line = line[:i] + } + line = bytes.TrimSpace(line) + if !bytes.HasPrefix(line, moduleStr) { + continue + } + line = line[len(moduleStr):] + n := len(line) + line = bytes.TrimSpace(line) + if len(line) == n || len(line) == 0 { + continue + } + + if line[0] == '"' || line[0] == '`' { + p, err := strconv.Unquote(string(line)) + if err != nil { + return "" // malformed quoted string or multiline module path + } + return p + } + + return string(line) + } + return "" // missing module path +} diff --git a/internal/mod/modfile/rule.go b/internal/mod/modfile/rule.go new file mode 100644 index 0000000000..163a2db0a7 --- /dev/null +++ b/internal/mod/modfile/rule.go @@ -0,0 +1,361 @@ +// 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 modfile implements a parser and formatter for go.mod files. +// +// The go.mod syntax is described in +// https://golang.org/cmd/go/#hdr-The_go_mod_file. +// +// The Parse and ParseLax functions both parse a go.mod file and return an +// abstract syntax tree. ParseLax ignores unknown statements and may be used to +// parse go.mod files that may have been developed with newer versions of Go. +// +// The File struct returned by Parse and ParseLax represent an abstract +// go.mod file. File has several methods like AddNewRequire and DropReplace +// that can be used to programmatically edit a file. +// +// The Format function formats a File back to a byte slice which can be +// written to a file. +package modfile + +import ( + "errors" + "fmt" + "path/filepath" + "strconv" + "strings" + "unicode" + + "golang.org/x/mod/modfile" + "golang.org/x/mod/module" + "golang.org/x/tools/internal/mod/lazyregexp" +) + +// A WorkFile is the parsed, interpreted form of a go.work file. +type WorkFile struct { + Go *modfile.Go + Directory []*Directory + Replace []*modfile.Replace + + Syntax *modfile.FileSyntax +} + +// A Directory is a single directory statement. +type Directory struct { + DiskPath string // TODO(matloob): Replace uses module.Version for new. Do that here? + ModulePath string // Module path in the comment. + Syntax *modfile.Line +} + +// Parse parses and returns a go.work file. +// +// file is the name of the file, used in positions and errors. +// +// data is the content of the file. +// +// fix is an optional function that canonicalizes module versions. +// If fix is nil, all module versions must be canonical (module.CanonicalVersion +// must return the same string). +func ParseWork(file string, data []byte, fix modfile.VersionFixer) (*WorkFile, error) { + return parseToWorkFile(file, data, fix, true) +} + +var GoVersionRE = lazyregexp.New(`^([1-9][0-9]*)\.(0|[1-9][0-9]*)$`) + +func parseToWorkFile(file string, data []byte, fix modfile.VersionFixer, strict bool) (parsed *WorkFile, err error) { + fs, err := parse(file, data) + if err != nil { + return nil, err + } + f := &WorkFile{ + Syntax: fs, + } + var errs modfile.ErrorList + + for _, x := range fs.Stmt { + switch x := x.(type) { + case *modfile.Line: + f.add(&errs, nil, x, x.Token[0], x.Token[1:], fix, strict) + + case *modfile.LineBlock: + if len(x.Token) > 1 { + if strict { + errs = append(errs, modfile.Error{ + Filename: file, + Pos: x.Start, + Err: fmt.Errorf("unknown block type: %s", strings.Join(x.Token, " ")), + }) + } + continue + } + switch x.Token[0] { + default: + if strict { + errs = append(errs, modfile.Error{ + Filename: file, + Pos: x.Start, + Err: fmt.Errorf("unknown block type: %s", strings.Join(x.Token, " ")), + }) + } + continue + case "module", "directory", "replace": + for _, l := range x.Line { + f.add(&errs, x, l, x.Token[0], l.Token, fix, strict) + } + } + } + } + + if len(errs) > 0 { + return nil, errs + } + return f, nil +} + +func (f *WorkFile) add(errs *modfile.ErrorList, block *modfile.LineBlock, line *modfile.Line, verb string, args []string, fix modfile.VersionFixer, strict bool) { + // If strict is false, this module is a dependency. + // We ignore all unknown directives as well as main-module-only + // directives like replace and exclude. It will work better for + // forward compatibility if we can depend on modules that have unknown + // statements (presumed relevant only when acting as the main module) + // and simply ignore those statements. + if !strict { + switch verb { + case "go", "module", "retract", "require": + // want these even for dependency go.mods + default: + return + } + } + + wrapModPathError := func(modPath string, err error) { + *errs = append(*errs, modfile.Error{ + Filename: f.Syntax.Name, + Pos: line.Start, + ModPath: modPath, + Verb: verb, + Err: err, + }) + } + wrapError := func(err error) { + *errs = append(*errs, modfile.Error{ + Filename: f.Syntax.Name, + Pos: line.Start, + Err: err, + }) + } + errorf := func(format string, args ...interface{}) { + wrapError(fmt.Errorf(format, args...)) + } + + switch verb { + default: + errorf("unknown directive: %s", verb) + + case "go": + if f.Go != nil { + errorf("repeated go statement") + return + } + if len(args) != 1 { + errorf("go directive expects exactly one argument") + return + } else if !GoVersionRE.MatchString(args[0]) { + errorf("invalid go version '%s': must match format 1.23", args[0]) + return + } + + f.Go = &modfile.Go{Syntax: line} + f.Go.Version = args[0] + + case "directory": + if len(args) != 1 { + errorf("usage: %s ../local/directory", verb) // TODO(matloob) better example; most directories will be subdirectories of go.work dir + return + } + s, err := parseString(&args[0]) + if err != nil { + errorf("invalid quoted string: %v", err) + return + } + f.Directory = append(f.Directory, &Directory{ + DiskPath: s, + Syntax: line, + }) + + case "replace": + arrow := 2 + if len(args) >= 2 && args[1] == "=>" { + arrow = 1 + } + if len(args) < arrow+2 || len(args) > arrow+3 || args[arrow] != "=>" { + errorf("usage: %s module/path [v1.2.3] => other/module v1.4\n\t or %s module/path [v1.2.3] => ../local/directory", verb, verb) + return + } + s, err := parseString(&args[0]) + if err != nil { + errorf("invalid quoted string: %v", err) + return + } + pathMajor, err := modulePathMajor(s) + if err != nil { + wrapModPathError(s, err) + return + } + var v string + if arrow == 2 { + v, err = parseVersion(verb, s, &args[1], fix) + if err != nil { + wrapError(err) + return + } + if err := module.CheckPathMajor(v, pathMajor); err != nil { + wrapModPathError(s, err) + return + } + } + ns, err := parseString(&args[arrow+1]) + if err != nil { + errorf("invalid quoted string: %v", err) + return + } + nv := "" + if len(args) == arrow+2 { + if !IsDirectoryPath(ns) { + errorf("replacement module without version must be directory path (rooted or starting with ./ or ../)") + return + } + if filepath.Separator == '/' && strings.Contains(ns, `\`) { + errorf("replacement directory appears to be Windows path (on a non-windows system)") + return + } + } + if len(args) == arrow+3 { + nv, err = parseVersion(verb, ns, &args[arrow+2], fix) + if err != nil { + wrapError(err) + return + } + if IsDirectoryPath(ns) { + errorf("replacement module directory path %q cannot have version", ns) + return + } + } + f.Replace = append(f.Replace, &modfile.Replace{ + Old: module.Version{Path: s, Version: v}, + New: module.Version{Path: ns, Version: nv}, + Syntax: line, + }) + } +} + +// IsDirectoryPath reports whether the given path should be interpreted +// as a directory path. Just like on the go command line, relative paths +// and rooted paths are directory paths; the rest are module paths. +func IsDirectoryPath(ns string) bool { + // Because go.mod files can move from one system to another, + // we check all known path syntaxes, both Unix and Windows. + return strings.HasPrefix(ns, "./") || strings.HasPrefix(ns, "../") || strings.HasPrefix(ns, "/") || + strings.HasPrefix(ns, `.\`) || strings.HasPrefix(ns, `..\`) || strings.HasPrefix(ns, `\`) || + len(ns) >= 2 && ('A' <= ns[0] && ns[0] <= 'Z' || 'a' <= ns[0] && ns[0] <= 'z') && ns[1] == ':' +} + +// MustQuote reports whether s must be quoted in order to appear as +// a single token in a go.mod line. +func MustQuote(s string) bool { + for _, r := range s { + switch r { + case ' ', '"', '\'', '`': + return true + + case '(', ')', '[', ']', '{', '}', ',': + if len(s) > 1 { + return true + } + + default: + if !unicode.IsPrint(r) { + return true + } + } + } + return s == "" || strings.Contains(s, "//") || strings.Contains(s, "/*") +} + +// AutoQuote returns s or, if quoting is required for s to appear in a go.mod, +// the quotation of s. +func AutoQuote(s string) string { + if MustQuote(s) { + return strconv.Quote(s) + } + return s +} + +func parseString(s *string) (string, error) { + t := *s + if strings.HasPrefix(t, `"`) { + var err error + if t, err = strconv.Unquote(t); err != nil { + return "", err + } + } else if strings.ContainsAny(t, "\"'`") { + // Other quotes are reserved both for possible future expansion + // and to avoid confusion. For example if someone types 'x' + // we want that to be a syntax error and not a literal x in literal quotation marks. + return "", fmt.Errorf("unquoted string cannot contain quote") + } + *s = AutoQuote(t) + return t, nil +} + +func parseVersion(verb string, path string, s *string, fix modfile.VersionFixer) (string, error) { + t, err := parseString(s) + if err != nil { + return "", &modfile.Error{ + Verb: verb, + ModPath: path, + Err: &module.InvalidVersionError{ + Version: *s, + Err: err, + }, + } + } + if fix != nil { + fixed, err := fix(path, t) + if err != nil { + if err, ok := err.(*module.ModuleError); ok { + return "", &modfile.Error{ + Verb: verb, + ModPath: path, + Err: err.Err, + } + } + return "", err + } + t = fixed + } else { + cv := module.CanonicalVersion(t) + if cv == "" { + return "", &modfile.Error{ + Verb: verb, + ModPath: path, + Err: &module.InvalidVersionError{ + Version: t, + Err: errors.New("must be of the form v1.2.3"), + }, + } + } + t = cv + } + *s = t + return *s, nil +} + +func modulePathMajor(path string) (string, error) { + _, major, ok := module.SplitPathVersion(path) + if !ok { + return "", fmt.Errorf("invalid module path") + } + return major, nil +}