blob: 91ca6828df09a4c6fe4a1021d35db6258b6a6f1b [file] [log] [blame]
// 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"
"sort"
"strconv"
"strings"
"unicode"
"golang.org/x/mod/internal/lazyregexp"
"golang.org/x/mod/module"
)
// A File is the parsed, interpreted form of a go.mod file.
type File struct {
Module *Module
Go *Go
Require []*Require
Exclude []*Exclude
Replace []*Replace
Syntax *FileSyntax
}
// A Module is the module statement.
type Module struct {
Mod module.Version
Syntax *Line
}
// A Go is the go statement.
type Go struct {
Version string // "1.23"
Syntax *Line
}
// A Require is a single require statement.
type Require struct {
Mod module.Version
Indirect bool // has "// indirect" comment
Syntax *Line
}
// An Exclude is a single exclude statement.
type Exclude struct {
Mod module.Version
Syntax *Line
}
// A Replace is a single replace statement.
type Replace struct {
Old module.Version
New module.Version
Syntax *Line
}
func (f *File) AddModuleStmt(path string) error {
if f.Syntax == nil {
f.Syntax = new(FileSyntax)
}
if f.Module == nil {
f.Module = &Module{
Mod: module.Version{Path: path},
Syntax: f.Syntax.addLine(nil, "module", AutoQuote(path)),
}
} else {
f.Module.Mod.Path = path
f.Syntax.updateLine(f.Module.Syntax, "module", AutoQuote(path))
}
return nil
}
func (f *File) AddComment(text string) {
if f.Syntax == nil {
f.Syntax = new(FileSyntax)
}
f.Syntax.Stmt = append(f.Syntax.Stmt, &CommentBlock{
Comments: Comments{
Before: []Comment{
{
Token: text,
},
},
},
})
}
type VersionFixer func(path, version string) (string, error)
// Parse parses the data, reported in errors as being from file,
// into a File struct. It applies fix, if non-nil, to canonicalize all module versions found.
func Parse(file string, data []byte, fix VersionFixer) (*File, error) {
return parseToFile(file, data, fix, true)
}
// ParseLax is like Parse but ignores unknown statements.
// It is used when parsing go.mod files other than the main module,
// under the theory that most statement types we add in the future will
// only apply in the main module, like exclude and replace,
// and so we get better gradual deployments if old go commands
// simply ignore those statements when found in go.mod files
// in dependencies.
func ParseLax(file string, data []byte, fix VersionFixer) (*File, error) {
return parseToFile(file, data, fix, false)
}
func parseToFile(file string, data []byte, fix VersionFixer, strict bool) (*File, error) {
fs, err := parse(file, data)
if err != nil {
return nil, err
}
f := &File{
Syntax: fs,
}
var errs ErrorList
for _, x := range fs.Stmt {
switch x := x.(type) {
case *Line:
f.add(&errs, x, x.Token[0], x.Token[1:], fix, strict)
case *LineBlock:
if len(x.Token) > 1 {
if strict {
errs = append(errs, 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, Error{
Filename: file,
Pos: x.Start,
Err: fmt.Errorf("unknown block type: %s", strings.Join(x.Token, " ")),
})
}
continue
case "module", "require", "exclude", "replace":
for _, l := range x.Line {
f.add(&errs, l, x.Token[0], l.Token, fix, strict)
}
}
}
}
if len(errs) > 0 {
return nil, errs
}
return f, nil
}
var GoVersionRE = lazyregexp.New(`^([1-9][0-9]*)\.(0|[1-9][0-9]*)$`)
func (f *File) add(errs *ErrorList, line *Line, verb string, args []string, fix 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 "module", "require", "go":
// want these even for dependency go.mods
default:
return
}
}
wrapModPathError := func(modPath string, err error) {
*errs = append(*errs, Error{
Filename: f.Syntax.Name,
Pos: line.Start,
ModPath: modPath,
Verb: verb,
Err: err,
})
}
wrapError := func(err error) {
*errs = append(*errs, 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 = &Go{Syntax: line}
f.Go.Version = args[0]
case "module":
if f.Module != nil {
errorf("repeated module statement")
return
}
f.Module = &Module{Syntax: line}
if len(args) != 1 {
errorf("usage: module module/path")
return
}
s, err := parseString(&args[0])
if err != nil {
errorf("invalid quoted string: %v", err)
return
}
f.Module.Mod = module.Version{Path: s}
case "require", "exclude":
if len(args) != 2 {
errorf("usage: %s module/path v1.2.3", verb)
return
}
s, err := parseString(&args[0])
if err != nil {
errorf("invalid quoted string: %v", err)
return
}
v, err := parseVersion(verb, s, &args[1], fix)
if err != nil {
wrapError(err)
return
}
pathMajor, err := modulePathMajor(s)
if err != nil {
wrapError(err)
return
}
if err := module.CheckPathMajor(v, pathMajor); err != nil {
wrapModPathError(s, err)
return
}
if verb == "require" {
f.Require = append(f.Require, &Require{
Mod: module.Version{Path: s, Version: v},
Syntax: line,
Indirect: isIndirect(line),
})
} else {
f.Exclude = append(f.Exclude, &Exclude{
Mod: module.Version{Path: s, Version: v},
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, &Replace{
Old: module.Version{Path: s, Version: v},
New: module.Version{Path: ns, Version: nv},
Syntax: line,
})
}
}
// isIndirect reports whether line has a "// indirect" comment,
// meaning it is in go.mod only for its effect on indirect dependencies,
// so that it can be dropped entirely once the effective version of the
// indirect dependency reaches the given minimum version.
func isIndirect(line *Line) bool {
if len(line.Suffix) == 0 {
return false
}
f := strings.Fields(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
return (len(f) == 1 && f[0] == "indirect" || len(f) > 1 && f[0] == "indirect;")
}
// setIndirect sets line to have (or not have) a "// indirect" comment.
func setIndirect(line *Line, indirect bool) {
if isIndirect(line) == indirect {
return
}
if indirect {
// Adding comment.
if len(line.Suffix) == 0 {
// New comment.
line.Suffix = []Comment{{Token: "// indirect", Suffix: true}}
return
}
com := &line.Suffix[0]
text := strings.TrimSpace(strings.TrimPrefix(com.Token, string(slashSlash)))
if text == "" {
// Empty comment.
com.Token = "// indirect"
return
}
// Insert at beginning of existing comment.
com.Token = "// indirect; " + text
return
}
// Removing comment.
f := strings.Fields(line.Suffix[0].Token)
if len(f) == 2 {
// Remove whole comment.
line.Suffix = nil
return
}
// Remove comment prefix.
com := &line.Suffix[0]
i := strings.Index(com.Token, "indirect;")
com.Token = "//" + com.Token[i+len("indirect;"):]
}
// 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
}
type ErrorList []Error
func (e ErrorList) Error() string {
errStrs := make([]string, len(e))
for i, err := range e {
errStrs[i] = err.Error()
}
return strings.Join(errStrs, "\n")
}
type Error struct {
Filename string
Pos Position
Verb string
ModPath string
Err error
}
func (e *Error) Error() string {
var pos string
if e.Pos.LineRune > 1 {
// Don't print LineRune if it's 1 (beginning of line).
// It's always 1 except in scanner errors, which are rare.
pos = fmt.Sprintf("%s:%d:%d: ", e.Filename, e.Pos.Line, e.Pos.LineRune)
} else if e.Pos.Line > 0 {
pos = fmt.Sprintf("%s:%d: ", e.Filename, e.Pos.Line)
} else if e.Filename != "" {
pos = fmt.Sprintf("%s: ", e.Filename)
}
var directive string
if e.ModPath != "" {
directive = fmt.Sprintf("%s %s: ", e.Verb, e.ModPath)
}
return pos + directive + e.Err.Error()
}
func (e *Error) Unwrap() error { return e.Err }
func parseVersion(verb string, path string, s *string, fix VersionFixer) (string, error) {
t, err := parseString(s)
if err != nil {
return "", &Error{
Verb: verb,
ModPath: path,
Err: &module.InvalidVersionError{
Version: *s,
Err: err,
},
}
}
if fix != nil {
var err error
t, err = fix(path, t)
if err != nil {
if err, ok := err.(*module.ModuleError); ok {
return "", &Error{
Verb: verb,
ModPath: path,
Err: err.Err,
}
}
return "", err
}
}
if v := module.CanonicalVersion(t); v != "" {
*s = v
return *s, nil
}
return "", &Error{
Verb: verb,
ModPath: path,
Err: &module.InvalidVersionError{
Version: t,
Err: errors.New("must be of the form v1.2.3"),
},
}
}
func modulePathMajor(path string) (string, error) {
_, major, ok := module.SplitPathVersion(path)
if !ok {
return "", fmt.Errorf("invalid module path")
}
return major, nil
}
func (f *File) Format() ([]byte, error) {
return Format(f.Syntax), nil
}
// Cleanup cleans up the file f after any edit operations.
// To avoid quadratic behavior, modifications like DropRequire
// clear the entry but do not remove it from the slice.
// Cleanup cleans out all the cleared entries.
func (f *File) Cleanup() {
w := 0
for _, r := range f.Require {
if r.Mod.Path != "" {
f.Require[w] = r
w++
}
}
f.Require = f.Require[:w]
w = 0
for _, x := range f.Exclude {
if x.Mod.Path != "" {
f.Exclude[w] = x
w++
}
}
f.Exclude = f.Exclude[:w]
w = 0
for _, r := range f.Replace {
if r.Old.Path != "" {
f.Replace[w] = r
w++
}
}
f.Replace = f.Replace[:w]
f.Syntax.Cleanup()
}
func (f *File) AddGoStmt(version string) error {
if !GoVersionRE.MatchString(version) {
return fmt.Errorf("invalid language version string %q", version)
}
if f.Go == nil {
var hint Expr
if f.Module != nil && f.Module.Syntax != nil {
hint = f.Module.Syntax
}
f.Go = &Go{
Version: version,
Syntax: f.Syntax.addLine(hint, "go", version),
}
} else {
f.Go.Version = version
f.Syntax.updateLine(f.Go.Syntax, "go", version)
}
return nil
}
func (f *File) AddRequire(path, vers string) error {
need := true
for _, r := range f.Require {
if r.Mod.Path == path {
if need {
r.Mod.Version = vers
f.Syntax.updateLine(r.Syntax, "require", AutoQuote(path), vers)
need = false
} else {
f.Syntax.removeLine(r.Syntax)
*r = Require{}
}
}
}
if need {
f.AddNewRequire(path, vers, false)
}
return nil
}
func (f *File) AddNewRequire(path, vers string, indirect bool) {
line := f.Syntax.addLine(nil, "require", AutoQuote(path), vers)
setIndirect(line, indirect)
f.Require = append(f.Require, &Require{module.Version{Path: path, Version: vers}, indirect, line})
}
func (f *File) SetRequire(req []*Require) {
need := make(map[string]string)
indirect := make(map[string]bool)
for _, r := range req {
need[r.Mod.Path] = r.Mod.Version
indirect[r.Mod.Path] = r.Indirect
}
for _, r := range f.Require {
if v, ok := need[r.Mod.Path]; ok {
r.Mod.Version = v
r.Indirect = indirect[r.Mod.Path]
} else {
*r = Require{}
}
}
var newStmts []Expr
for _, stmt := range f.Syntax.Stmt {
switch stmt := stmt.(type) {
case *LineBlock:
if len(stmt.Token) > 0 && stmt.Token[0] == "require" {
var newLines []*Line
for _, line := range stmt.Line {
if p, err := parseString(&line.Token[0]); err == nil && need[p] != "" {
if len(line.Comments.Before) == 1 && len(line.Comments.Before[0].Token) == 0 {
line.Comments.Before = line.Comments.Before[:0]
}
line.Token[1] = need[p]
delete(need, p)
setIndirect(line, indirect[p])
newLines = append(newLines, line)
}
}
if len(newLines) == 0 {
continue // drop stmt
}
stmt.Line = newLines
}
case *Line:
if len(stmt.Token) > 0 && stmt.Token[0] == "require" {
if p, err := parseString(&stmt.Token[1]); err == nil && need[p] != "" {
stmt.Token[2] = need[p]
delete(need, p)
setIndirect(stmt, indirect[p])
} else {
continue // drop stmt
}
}
}
newStmts = append(newStmts, stmt)
}
f.Syntax.Stmt = newStmts
for path, vers := range need {
f.AddNewRequire(path, vers, indirect[path])
}
f.SortBlocks()
}
func (f *File) DropRequire(path string) error {
for _, r := range f.Require {
if r.Mod.Path == path {
f.Syntax.removeLine(r.Syntax)
*r = Require{}
}
}
return nil
}
func (f *File) AddExclude(path, vers string) error {
var hint *Line
for _, x := range f.Exclude {
if x.Mod.Path == path && x.Mod.Version == vers {
return nil
}
if x.Mod.Path == path {
hint = x.Syntax
}
}
f.Exclude = append(f.Exclude, &Exclude{Mod: module.Version{Path: path, Version: vers}, Syntax: f.Syntax.addLine(hint, "exclude", AutoQuote(path), vers)})
return nil
}
func (f *File) DropExclude(path, vers string) error {
for _, x := range f.Exclude {
if x.Mod.Path == path && x.Mod.Version == vers {
f.Syntax.removeLine(x.Syntax)
*x = Exclude{}
}
}
return nil
}
func (f *File) AddReplace(oldPath, oldVers, newPath, newVers string) error {
need := true
old := module.Version{Path: oldPath, Version: oldVers}
new := module.Version{Path: newPath, Version: newVers}
tokens := []string{"replace", AutoQuote(oldPath)}
if oldVers != "" {
tokens = append(tokens, oldVers)
}
tokens = append(tokens, "=>", AutoQuote(newPath))
if newVers != "" {
tokens = append(tokens, newVers)
}
var hint *Line
for _, r := range f.Replace {
if r.Old.Path == oldPath && (oldVers == "" || r.Old.Version == oldVers) {
if need {
// Found replacement for old; update to use new.
r.New = new
f.Syntax.updateLine(r.Syntax, tokens...)
need = false
continue
}
// Already added; delete other replacements for same.
f.Syntax.removeLine(r.Syntax)
*r = Replace{}
}
if r.Old.Path == oldPath {
hint = r.Syntax
}
}
if need {
f.Replace = append(f.Replace, &Replace{Old: old, New: new, Syntax: f.Syntax.addLine(hint, tokens...)})
}
return nil
}
func (f *File) DropReplace(oldPath, oldVers string) error {
for _, r := range f.Replace {
if r.Old.Path == oldPath && r.Old.Version == oldVers {
f.Syntax.removeLine(r.Syntax)
*r = Replace{}
}
}
return nil
}
func (f *File) SortBlocks() {
f.removeDups() // otherwise sorting is unsafe
for _, stmt := range f.Syntax.Stmt {
block, ok := stmt.(*LineBlock)
if !ok {
continue
}
sort.Slice(block.Line, func(i, j int) bool {
li := block.Line[i]
lj := block.Line[j]
for k := 0; k < len(li.Token) && k < len(lj.Token); k++ {
if li.Token[k] != lj.Token[k] {
return li.Token[k] < lj.Token[k]
}
}
return len(li.Token) < len(lj.Token)
})
}
}
func (f *File) removeDups() {
have := make(map[module.Version]bool)
kill := make(map[*Line]bool)
for _, x := range f.Exclude {
if have[x.Mod] {
kill[x.Syntax] = true
continue
}
have[x.Mod] = true
}
var excl []*Exclude
for _, x := range f.Exclude {
if !kill[x.Syntax] {
excl = append(excl, x)
}
}
f.Exclude = excl
have = make(map[module.Version]bool)
// Later replacements take priority over earlier ones.
for i := len(f.Replace) - 1; i >= 0; i-- {
x := f.Replace[i]
if have[x.Old] {
kill[x.Syntax] = true
continue
}
have[x.Old] = true
}
var repl []*Replace
for _, x := range f.Replace {
if !kill[x.Syntax] {
repl = append(repl, x)
}
}
f.Replace = repl
var stmts []Expr
for _, stmt := range f.Syntax.Stmt {
switch stmt := stmt.(type) {
case *Line:
if kill[stmt] {
continue
}
case *LineBlock:
var lines []*Line
for _, line := range stmt.Line {
if !kill[line] {
lines = append(lines, line)
}
}
stmt.Line = lines
if len(lines) == 0 {
continue
}
}
stmts = append(stmts, stmt)
}
f.Syntax.Stmt = stmts
}