blob: f45796cc1d80679e040adce10fd1332989204309 [file] [log] [blame]
// Copyright 2020 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 gc
import (
"cmd/compile/internal/syntax"
"cmd/compile/internal/types"
"cmd/internal/obj"
"encoding/json"
"io/ioutil"
"log"
"path"
"sort"
"strconv"
"strings"
)
var embedlist []*Node
var embedCfg struct {
Patterns map[string][]string
Files map[string]string
}
func readEmbedCfg(file string) {
data, err := ioutil.ReadFile(file)
if err != nil {
log.Fatalf("-embedcfg: %v", err)
}
if err := json.Unmarshal(data, &embedCfg); err != nil {
log.Fatalf("%s: %v", file, err)
}
if embedCfg.Patterns == nil {
log.Fatalf("%s: invalid embedcfg: missing Patterns", file)
}
if embedCfg.Files == nil {
log.Fatalf("%s: invalid embedcfg: missing Files", file)
}
}
const (
embedUnknown = iota
embedBytes
embedString
embedFiles
)
func varEmbed(p *noder, names []*Node, typ *Node, exprs []*Node, embeds []PragmaEmbed) {
haveEmbed := false
for _, decl := range p.file.DeclList {
imp, ok := decl.(*syntax.ImportDecl)
if !ok {
// imports always come first
break
}
path, _ := strconv.Unquote(imp.Path.Value)
if path == "embed" {
haveEmbed = true
break
}
}
pos := embeds[0].Pos
if !haveEmbed {
p.yyerrorpos(pos, "invalid go:embed: missing import \"embed\"")
return
}
if len(names) > 1 {
p.yyerrorpos(pos, "go:embed cannot apply to multiple vars")
return
}
if len(exprs) > 0 {
p.yyerrorpos(pos, "go:embed cannot apply to var with initializer")
return
}
if typ == nil {
// Should not happen, since len(exprs) == 0 now.
p.yyerrorpos(pos, "go:embed cannot apply to var without type")
return
}
if dclcontext != PEXTERN {
p.yyerrorpos(pos, "go:embed cannot apply to var inside func")
return
}
var list []irEmbed
for _, e := range embeds {
list = append(list, irEmbed{Pos: p.makeXPos(e.Pos), Patterns: e.Patterns})
}
v := names[0]
v.Name.Param.SetEmbedList(list)
embedlist = append(embedlist, v)
}
func embedFileList(v *Node, kind int) []string {
// Build list of files to store.
have := make(map[string]bool)
var list []string
for _, e := range v.Name.Param.EmbedList() {
for _, pattern := range e.Patterns {
files, ok := embedCfg.Patterns[pattern]
if !ok {
yyerrorl(e.Pos, "invalid go:embed: build system did not map pattern: %s", pattern)
}
for _, file := range files {
if embedCfg.Files[file] == "" {
yyerrorl(e.Pos, "invalid go:embed: build system did not map file: %s", file)
continue
}
if !have[file] {
have[file] = true
list = append(list, file)
}
if kind == embedFiles {
for dir := path.Dir(file); dir != "." && !have[dir]; dir = path.Dir(dir) {
have[dir] = true
list = append(list, dir+"/")
}
}
}
}
}
sort.Slice(list, func(i, j int) bool {
return embedFileLess(list[i], list[j])
})
if kind == embedString || kind == embedBytes {
if len(list) > 1 {
yyerrorl(v.Pos, "invalid go:embed: multiple files for type %v", v.Type)
return nil
}
}
return list
}
// embedKind determines the kind of embedding variable.
func embedKind(typ *types.Type) int {
if typ.Sym != nil && typ.Sym.Name == "FS" && (typ.Sym.Pkg.Path == "embed" || (typ.Sym.Pkg == localpkg && myimportpath == "embed")) {
return embedFiles
}
if typ.Etype == types.TSTRING {
return embedString
}
if typ.Etype == types.TSLICE && typ.Elem().Etype == types.TUINT8 {
return embedBytes
}
return embedUnknown
}
func embedFileNameSplit(name string) (dir, elem string, isDir bool) {
if name[len(name)-1] == '/' {
isDir = true
name = name[:len(name)-1]
}
i := len(name) - 1
for i >= 0 && name[i] != '/' {
i--
}
if i < 0 {
return ".", name, isDir
}
return name[:i], name[i+1:], isDir
}
// embedFileLess implements the sort order for a list of embedded files.
// See the comment inside ../../../../embed/embed.go's Files struct for rationale.
func embedFileLess(x, y string) bool {
xdir, xelem, _ := embedFileNameSplit(x)
ydir, yelem, _ := embedFileNameSplit(y)
return xdir < ydir || xdir == ydir && xelem < yelem
}
func dumpembeds() {
for _, v := range embedlist {
initEmbed(v)
}
}
// initEmbed emits the init data for a //go:embed variable,
// which is either a string, a []byte, or an embed.FS.
func initEmbed(v *Node) {
commentPos := v.Name.Param.EmbedList()[0].Pos
if !langSupported(1, 16, localpkg) {
lno := lineno
lineno = commentPos
yyerrorv("go1.16", "go:embed")
lineno = lno
return
}
if embedCfg.Patterns == nil {
yyerrorl(commentPos, "invalid go:embed: build system did not supply embed configuration")
return
}
kind := embedKind(v.Type)
if kind == embedUnknown {
yyerrorl(v.Pos, "go:embed cannot apply to var of type %v", v.Type)
return
}
files := embedFileList(v, kind)
switch kind {
case embedString, embedBytes:
file := files[0]
fsym, size, err := fileStringSym(v.Pos, embedCfg.Files[file], kind == embedString, nil)
if err != nil {
yyerrorl(v.Pos, "embed %s: %v", file, err)
}
sym := v.Sym.Linksym()
off := 0
off = dsymptr(sym, off, fsym, 0) // data string
off = duintptr(sym, off, uint64(size)) // len
if kind == embedBytes {
duintptr(sym, off, uint64(size)) // cap for slice
}
case embedFiles:
slicedata := Ctxt.Lookup(`"".` + v.Sym.Name + `.files`)
off := 0
// []files pointed at by Files
off = dsymptr(slicedata, off, slicedata, 3*Widthptr) // []file, pointing just past slice
off = duintptr(slicedata, off, uint64(len(files)))
off = duintptr(slicedata, off, uint64(len(files)))
// embed/embed.go type file is:
// name string
// data string
// hash [16]byte
// Emit one of these per file in the set.
const hashSize = 16
hash := make([]byte, hashSize)
for _, file := range files {
off = dsymptr(slicedata, off, stringsym(v.Pos, file), 0) // file string
off = duintptr(slicedata, off, uint64(len(file)))
if strings.HasSuffix(file, "/") {
// entry for directory - no data
off = duintptr(slicedata, off, 0)
off = duintptr(slicedata, off, 0)
off += hashSize
} else {
fsym, size, err := fileStringSym(v.Pos, embedCfg.Files[file], true, hash)
if err != nil {
yyerrorl(v.Pos, "embed %s: %v", file, err)
}
off = dsymptr(slicedata, off, fsym, 0) // data string
off = duintptr(slicedata, off, uint64(size))
off = int(slicedata.WriteBytes(Ctxt, int64(off), hash))
}
}
ggloblsym(slicedata, int32(off), obj.RODATA|obj.LOCAL)
sym := v.Sym.Linksym()
dsymptr(sym, 0, slicedata, 0)
}
}