GoToSocial/vendor/modernc.org/gc/v3/gc.go

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// Copyright 2022 The Gc Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate stringer -output stringer.go -linecomment -type=Kind,ScopeKind,ChanDir,TypeCheck
package gc // modernc.org/gc/v3
import (
"fmt"
"go/build"
"go/build/constraint"
"go/token"
"io"
"io/fs"
"os"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"unicode"
"github.com/hashicorp/golang-lru/v2"
)
var (
trcErrors bool
)
type FileFilter func(cfg *Config, importPath string, matchedFSPaths []string, withTestFiles bool) (pkgFiles []string, err error)
type TypeCheck int
const (
TypeCheckNone TypeCheck = iota
TypeCheckAll
)
type cacheKey struct {
buildTagsKey string
cfg *Config
fsPath string
goarch string
goos string
gopathKey string
goroot string
importPath string
typeCheck TypeCheck
withTestFiles bool
}
type cacheItem struct {
pkg *Package
ch chan struct{}
}
func newCacheItem() *cacheItem { return &cacheItem{ch: make(chan struct{})} }
func (c *cacheItem) set(pkg *Package) {
c.pkg = pkg
close(c.ch)
}
func (c *cacheItem) wait() *Package {
<-c.ch
return c.pkg
}
type Cache struct {
sync.Mutex
lru *lru.TwoQueueCache[cacheKey, *cacheItem]
}
func NewCache(size int) (*Cache, error) {
c, err := lru.New2Q[cacheKey, *cacheItem](size)
if err != nil {
return nil, err
}
return &Cache{lru: c}, nil
}
func MustNewCache(size int) *Cache {
c, err := NewCache(size)
if err != nil {
panic(todo("", err))
}
return c
}
type ConfigOption func(*Config) error
// Config configures NewPackage
//
// Config instances can be shared, they are not mutated once created and
// configured.
type Config struct {
abi *ABI
buildTagMap map[string]bool
buildTags []string
buildTagsKey string // Zero byte separated
builtin *Package
cache *Cache
cmp *Package // Go 1.21
env map[string]string
fs fs.FS
goarch string
gocompiler string // "gc", "gccgo"
goos string
gopath string
gopathKey string // Zero byte separated
goroot string
goversion string
lookup func(rel, importPath, version string) (fsPath string, err error)
parallel *parallel
searchGoPaths []string
searchGoroot []string
int Type // Set by NewConfig
uint Type // Set by NewConfig
arch32bit bool
configured bool
}
// NewConfig returns a newly created config or an error, if any.
func NewConfig(opts ...ConfigOption) (r *Config, err error) {
r = &Config{
buildTagMap: map[string]bool{},
env: map[string]string{},
parallel: newParallel(),
}
defer func() {
if r != nil {
r.configured = true
}
}()
r.lookup = r.DefaultLookup
ctx := build.Default
r.goos = r.getenv("GOOS", ctx.GOOS)
r.goarch = r.getenv("GOARCH", ctx.GOARCH)
r.goroot = r.getenv("GOROOT", ctx.GOROOT)
r.gopath = r.getenv("GOPATH", ctx.GOPATH)
r.buildTags = append(r.buildTags, r.goos, r.goarch)
r.gocompiler = runtime.Compiler
for _, opt := range opts {
if err := opt(r); err != nil {
return nil, err
}
}
if r.abi, err = NewABI(r.goos, r.goarch); err != nil {
return nil, err
}
switch r.goarch {
case "386", "arm":
r.arch32bit = true
}
// During a particular build, the following build tags are satisfied:
//
// the target operating system, as spelled by runtime.GOOS, set with the GOOS environment variable.
// the target architecture, as spelled by runtime.GOARCH, set with the GOARCH environment variable.
// "unix", if GOOS is a Unix or Unix-like system.
// the compiler being used, either "gc" or "gccgo"
// "cgo", if the cgo command is supported (see CGO_ENABLED in 'go help environment').
// a term for each Go major release, through the current version: "go1.1" from Go version 1.1 onward, "go1.12" from Go 1.12, and so on.
// any additional tags given by the -tags flag (see 'go help build').
// There are no separate build tags for beta or minor releases.
if r.goversion == "" {
r.goversion = runtime.Version()
}
if !strings.HasPrefix(r.goversion, "go") || !strings.Contains(r.goversion, ".") {
return nil, fmt.Errorf("cannot parse Go version: %s", r.goversion)
}
ver := strings.SplitN(r.goversion[len("go"):], ".", 2)
verMajor, err := strconv.Atoi(ver[0])
if err != nil {
return nil, fmt.Errorf("cannot parse Go version %s: %v", r.goversion, err)
}
if verMajor != 1 {
return nil, fmt.Errorf("unsupported Go version: %s", r.goversion)
}
switch x, x2 := strings.IndexByte(ver[1], '.'), strings.Index(ver[1], "rc"); {
case x >= 0:
ver[1] = ver[1][:x]
case x2 >= 0:
ver[1] = ver[1][:x2]
}
verMinor, err := strconv.Atoi(ver[1])
if err != nil {
return nil, fmt.Errorf("cannot parse Go version %s: %v", r.goversion, err)
}
for i := 1; i <= verMinor; i++ {
r.buildTags = append(r.buildTags, fmt.Sprintf("go%d.%d", verMajor, i))
}
r.buildTags = append(r.buildTags, r.gocompiler)
r.buildTags = append(r.buildTags, extraTags(verMajor, verMinor, r.goos, r.goarch)...)
if r.getenv("CGO_ENABLED", "1") == "1" {
r.buildTags = append(r.buildTags, "cgo")
}
for i, v := range r.buildTags {
tag := strings.TrimSpace(v)
r.buildTags[i] = tag
r.buildTagMap[tag] = true
}
sort.Strings(r.buildTags)
r.buildTagsKey = strings.Join(r.buildTags, "\x00")
r.searchGoroot = []string{filepath.Join(r.goroot, "src")}
r.searchGoPaths = filepath.SplitList(r.gopath)
r.gopathKey = strings.Join(r.searchGoPaths, "\x00")
for i, v := range r.searchGoPaths {
r.searchGoPaths[i] = filepath.Join(v, "src")
}
switch r.cmp, err = r.NewPackage("", "cmp", "", nil, false, TypeCheckNone); {
case err != nil:
r.cmp = nil
default:
//TODO r.cmp.Scope.kind = UniverseScope
}
if r.builtin, err = r.NewPackage("", "builtin", "", nil, false, TypeCheckNone); err != nil {
return nil, err
}
r.builtin.Scope.kind = UniverseScope
if err := r.builtin.check(newCtx(r)); err != nil {
return nil, err
}
return r, nil
}
func (c *Config) universe() *Scope {
if c.builtin != nil {
return c.builtin.Scope
}
return nil
}
func (c *Config) stat(name string) (fs.FileInfo, error) {
if c.fs == nil {
return os.Stat(name)
}
name = filepath.ToSlash(name)
if x, ok := c.fs.(fs.StatFS); ok {
return x.Stat(name)
}
f, err := c.fs.Open(name)
if err != nil {
return nil, err
}
defer f.Close()
return f.Stat()
}
func (c *Config) open(name string) (fs.File, error) {
if c.fs == nil {
return os.Open(name)
}
name = filepath.ToSlash(name)
return c.fs.Open(name)
}
func (c *Config) glob(pattern string) (matches []string, err error) {
if c.fs == nil {
return filepath.Glob(pattern)
}
pattern = filepath.ToSlash(pattern)
return fs.Glob(c.fs, pattern)
}
func (c *Config) checkConstraints(pos token.Position, sep string) (r bool) {
if !strings.Contains(sep, "//go:build") && !strings.Contains(sep, "+build") {
return true
}
// defer func() { trc("", r) }()
lines := strings.Split(sep, "\n")
var build, plusBuild []string
for i, line := range lines {
if constraint.IsGoBuild(line) && i < len(lines)-1 && lines[i+1] == "" {
build = append(build, line)
}
if constraint.IsPlusBuild(line) {
plusBuild = append(plusBuild, line)
}
}
switch len(build) {
case 0:
// ok
case 1:
expr, err := constraint.Parse(build[0])
if err != nil {
return true
}
return expr.Eval(func(tag string) (r bool) {
// defer func() { trc("%q: %v", tag, r) }()
switch tag {
case "unix":
return unixOS[c.goos]
default:
return c.buildTagMap[tag]
}
})
default:
panic(todo("%v: %q", pos, build))
}
for _, line := range plusBuild {
expr, err := constraint.Parse(line)
if err != nil {
return true
}
if !expr.Eval(func(tag string) (r bool) {
// defer func() { trc("%q: %v", tag, r) }()
switch tag {
case "unix":
return unixOS[c.goos]
default:
return c.buildTagMap[tag]
}
}) {
return false
}
}
return true
}
// Default lookup translates import paths, possibly relative to rel, to file system paths.
func (c *Config) DefaultLookup(rel, importPath, version string) (fsPath string, err error) {
if importPath == "" {
return "", fmt.Errorf("import path cannot be emtpy")
}
// Implementation restriction: A compiler may restrict ImportPaths to non-empty
// strings using only characters belonging to Unicode's L, M, N, P, and S
// general categories (the Graphic characters without spaces) and may also
// exclude the characters !"#$%&'()*,:;<=>?[\]^`{|} and the Unicode replacement
// character U+FFFD.
if strings.ContainsAny(importPath, "!\"#$%&'()*,:;<=>?[\\]^`{|}\ufffd") {
return "", fmt.Errorf("invalid import path: %s", importPath)
}
for _, r := range importPath {
if !unicode.Is(unicode.L, r) &&
!unicode.Is(unicode.M, r) &&
!unicode.Is(unicode.N, r) &&
!unicode.Is(unicode.P, r) &&
!unicode.Is(unicode.S, r) {
return "", fmt.Errorf("invalid import path: %s", importPath)
}
}
var search []string
ip0 := importPath
switch slash := strings.IndexByte(importPath, '/'); {
case strings.HasPrefix(importPath, "./"):
if rel != "" {
panic(todo(""))
}
return "", fmt.Errorf("invalid import path: %s", importPath)
case strings.HasPrefix(importPath, "/"):
return importPath, nil
case slash > 0:
ip0 = importPath[:slash]
default:
ip0 = importPath
}
if ip0 != "" {
switch {
case strings.Contains(ip0, "."):
search = c.searchGoPaths
default:
search = c.searchGoroot
}
}
for _, v := range search {
fsPath = filepath.Join(v, importPath)
dir, err := c.open(fsPath)
if err != nil {
continue
}
fi, err := dir.Stat()
dir.Close()
if err != nil {
continue
}
if fi.IsDir() {
return fsPath, nil
}
}
return "", fmt.Errorf("cannot find package %s, searched %v", importPath, search)
}
func (c *Config) getenv(nm, deflt string) (r string) {
if r = c.env[nm]; r != "" {
return r
}
if r = os.Getenv(nm); r != "" {
return r
}
return deflt
}
func DefaultFileFilter(cfg *Config, importPath string, matchedFSPaths []string, withTestFiles bool) (pkgFiles []string, err error) {
w := 0
for _, v := range matchedFSPaths {
base := filepath.Base(v)
base = base[:len(base)-len(filepath.Ext(base))]
const testSuffix = "_test"
if strings.HasSuffix(base, testSuffix) {
if !withTestFiles {
continue
}
base = base[:len(base)-len(testSuffix)]
}
if x := strings.LastIndexByte(base, '_'); x > 0 {
last := base[x+1:]
base = base[:x]
var prevLast string
if x := strings.LastIndexByte(base, '_'); x > 0 {
prevLast = base[x+1:]
}
if last != "" && prevLast != "" {
// *_GOOS_GOARCH
if knownOS[prevLast] && prevLast != cfg.goos {
continue
}
if knownArch[last] && last != cfg.goarch {
continue
}
}
if last != "" {
// *_GOOS or *_GOARCH
if knownOS[last] && last != cfg.goos {
continue
}
if knownArch[last] && last != cfg.goarch {
continue
}
}
}
matchedFSPaths[w] = v
w++
}
return matchedFSPaths[:w], nil
}
// ConfigBuildTags configures build tags.
func ConfigBuildTags(tags []string) ConfigOption {
return func(cfg *Config) error {
if cfg.configured {
return fmt.Errorf("ConfigBuildTags: Config instance already configured")
}
cfg.buildTags = append(cfg.buildTags, tags...)
return nil
}
}
// ConfigEnviron configures environment variables.
func ConfigEnviron(env []string) ConfigOption {
return func(cfg *Config) error {
if cfg.configured {
return fmt.Errorf("ConfigEnviron: Config instance already configured")
}
for _, v := range env {
switch x := strings.IndexByte(v, '='); {
case x < 0:
cfg.env[v] = ""
default:
cfg.env[v[:x]] = v[x+1:]
}
}
return nil
}
}
// ConfigFS configures a file system used for opening Go source files. If not
// explicitly configured, a default os.DirFS("/") is used on Unix-like
// operating systems. On Windows it will be rooted on the volume where
// runtime.GOROOT() is.
func ConfigFS(fs fs.FS) ConfigOption {
return func(cfg *Config) error {
if cfg.configured {
return fmt.Errorf("ConfigFS: Config instance already configured")
}
cfg.fs = fs
return nil
}
}
// ConfigLookup configures a lookup function.
func ConfigLookup(f func(dir, importPath, version string) (fsPath string, err error)) ConfigOption {
return func(cfg *Config) error {
if cfg.configured {
return fmt.Errorf("ConfigLookup: Config instance already configured")
}
cfg.lookup = f
return nil
}
}
// ConfigCache configures a cache.
func ConfigCache(c *Cache) ConfigOption {
return func(cfg *Config) error {
if cfg.configured {
return fmt.Errorf("ConfigCache: Config instance already configured")
}
cfg.cache = c
return nil
}
}
type importGuard struct {
m map[string]struct{}
stack []string
}
func newImportGuard() *importGuard { return &importGuard{m: map[string]struct{}{}} }
// Package represents a Go package. The instance must not be mutated.
type Package struct {
AST map[string]*AST // AST maps fsPaths of individual files to their respective ASTs
FSPath string
GoFiles []fs.FileInfo
ImportPath string
InvalidGoFiles map[string]error // errors for particular files, if any
Name Token
Scope *Scope // Package scope.
Version string
cfg *Config
guard *importGuard
mu sync.Mutex
typeCheck TypeCheck
isUnsafe bool // ImportPath == "usnafe"
// isChecked bool
}
// NewPackage returns a Package, possibly cached, for importPath@version or an
// error, if any. The fileFilter argument can be nil, in such case
// DefaultFileFilter is used, which ignores Files with suffix _test.go unless
// withTestFiles is true.
//
// NewPackage is safe for concurrent use by multiple goroutines.
func (c *Config) NewPackage(dir, importPath, version string, fileFilter FileFilter, withTestFiles bool, typeCheck TypeCheck) (pkg *Package, err error) {
return c.newPackage(dir, importPath, version, fileFilter, withTestFiles, typeCheck, newImportGuard())
}
func (c *Config) newPackage(dir, importPath, version string, fileFilter FileFilter, withTestFiles bool, typeCheck TypeCheck, guard *importGuard) (pkg *Package, err error) {
if _, ok := guard.m[importPath]; ok {
return nil, fmt.Errorf("import cycle %v", guard.stack)
}
guard.stack = append(guard.stack, importPath)
fsPath, err := c.lookup(dir, importPath, version)
if err != nil {
return nil, fmt.Errorf("lookup %s: %v", importPath, err)
}
pat := filepath.Join(fsPath, "*.go")
matches, err := c.glob(pat)
if err != nil {
return nil, fmt.Errorf("glob %s: %v", pat, err)
}
if len(matches) == 0 {
return nil, fmt.Errorf("no Go files in %s", fsPath)
}
if fileFilter == nil {
fileFilter = DefaultFileFilter
}
if matches, err = fileFilter(c, importPath, matches, withTestFiles); err != nil {
return nil, fmt.Errorf("matching Go files in %s: %v", fsPath, err)
}
var k cacheKey
if c.cache != nil {
k = cacheKey{
buildTagsKey: c.buildTagsKey,
cfg: c,
fsPath: fsPath,
goarch: c.goarch,
goos: c.goos,
gopathKey: c.gopathKey,
goroot: c.goroot,
importPath: importPath,
typeCheck: typeCheck,
withTestFiles: withTestFiles,
}
c.cache.Lock() // ---------------------------------------- lock
item, ok := c.cache.lru.Get(k)
if ok {
c.cache.Unlock() // ---------------------------- unlock
if pkg = item.wait(); pkg != nil && pkg.matches(&k, matches) {
return pkg, nil
}
}
item = newCacheItem()
c.cache.lru.Add(k, item)
c.cache.Unlock() // ------------------------------------ unlock
defer func() {
if pkg != nil && err == nil {
item.set(pkg)
}
}()
}
r := &Package{
AST: map[string]*AST{},
FSPath: fsPath,
ImportPath: importPath,
Scope: newScope(c.universe(), PackageScope),
Version: version,
cfg: c,
guard: guard,
isUnsafe: importPath == "unsafe",
typeCheck: typeCheck,
}
defer func() { r.guard = nil }()
sort.Strings(matches)
defer func() {
sort.Slice(r.GoFiles, func(i, j int) bool { return r.GoFiles[i].Name() < r.GoFiles[j].Name() })
if err != nil || len(r.InvalidGoFiles) != 0 || typeCheck == TypeCheckNone {
return
}
//TODO err = r.check(newCtx(c))
}()
c.parallel.throttle(func() {
for _, path := range matches {
if err = c.newPackageFile(r, path); err != nil {
return
}
}
})
return r, err
}
func (c *Config) newPackageFile(pkg *Package, path string) (err error) {
f, err := c.open(path)
if err != nil {
return fmt.Errorf("opening file %q: %v", path, err)
}
defer func() {
f.Close()
if err != nil {
if pkg.InvalidGoFiles == nil {
pkg.InvalidGoFiles = map[string]error{}
}
pkg.InvalidGoFiles[path] = err
}
}()
var fi fs.FileInfo
if fi, err = f.Stat(); err != nil {
return fmt.Errorf("stat %s: %v", path, err)
}
if !fi.Mode().IsRegular() {
return nil
}
var b []byte
if b, err = io.ReadAll(f); err != nil {
return fmt.Errorf("reading %s: %v", path, err)
}
p := newParser(pkg.Scope, path, b, false)
if p.peek(0) == PACKAGE {
tok := Token{p.s.source, p.s.toks[p.ix].ch, int32(p.ix)}
if !c.checkConstraints(tok.Position(), tok.Sep()) {
return nil
}
}
pkg.GoFiles = append(pkg.GoFiles, fi)
var ast *AST
if ast, err = p.parse(); err != nil {
return nil
}
pkg.AST[path] = ast
return nil
}
func (p *Package) matches(k *cacheKey, matches []string) bool {
matched := map[string]struct{}{}
for _, match := range matches {
matched[match] = struct{}{}
}
for _, cachedInfo := range p.GoFiles {
name := cachedInfo.Name()
path := filepath.Join(p.FSPath, name)
if _, ok := matched[path]; !ok {
return false
}
info, err := k.cfg.stat(path)
if err != nil {
return false
}
if info.IsDir() ||
info.Size() != cachedInfo.Size() ||
info.ModTime().After(cachedInfo.ModTime()) ||
info.Mode() != cachedInfo.Mode() {
return false
}
}
return true
}
// ParseFile parses 'b', assuming it comes from 'path' and returns an AST or error, if any.
func ParseFile(path string, b []byte) (*AST, error) {
return newParser(newScope(nil, PackageScope), path, b, false).parse()
}