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cmd/compile: add //go:embed support

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This commit contains the compiler support for //go:embed lines.
The go command passes to the compiler an "embed config"
that maps literal patterns like *.txt to the set of files to embed.
The compiler then lays out the content of those files as static data
in the form of an embed.Files or string or []byte in the final object file.

The test for this code is the end-to-end test hooking up the
embed, cmd/compile, and cmd/go changes, in the next CL.

For #41191.

Change-Id: I916e57f8cc65871dc0044c13d3f90c252a3fe1bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/243944
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit is contained in:
Russ Cox 2020-07-19 00:32:02 -04:00
parent 400581b8b0
commit 8bde9b320e
8 changed files with 682 additions and 48 deletions
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273
src/cmd/compile/internal/gc/embed.go Normal file
View File

@ -0,0 +1,273 @@
// 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
)
var numLocalEmbed int
func varEmbed(p *noder, names []*Node, typ *Node, exprs []*Node, embeds []PragmaEmbed) (newExprs []*Node) {
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 exprs
}
if embedCfg.Patterns == nil {
p.yyerrorpos(pos, "invalid go:embed: build system did not supply embed configuration")
return exprs
}
if len(names) > 1 {
p.yyerrorpos(pos, "go:embed cannot apply to multiple vars")
return exprs
}
if len(exprs) > 0 {
p.yyerrorpos(pos, "go:embed cannot apply to var with initializer")
return exprs
}
if typ == nil {
// Should not happen, since len(exprs) == 0 now.
p.yyerrorpos(pos, "go:embed cannot apply to var without type")
return exprs
}
kind := embedKindApprox(typ)
if kind == embedUnknown {
p.yyerrorpos(pos, "go:embed cannot apply to var of type %v", typ)
return exprs
}
// Build list of files to store.
have := make(map[string]bool)
var list []string
for _, e := range embeds {
for _, pattern := range e.Patterns {
files, ok := embedCfg.Patterns[pattern]
if !ok {
p.yyerrorpos(e.Pos, "invalid go:embed: build system did not map pattern: %s", pattern)
}
for _, file := range files {
if embedCfg.Files[file] == "" {
p.yyerrorpos(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 {
p.yyerrorpos(pos, "invalid go:embed: multiple files for type %v", typ)
return exprs
}
}
v := names[0]
if dclcontext != PEXTERN {
numLocalEmbed++
v = newnamel(v.Pos, lookupN("embed.", numLocalEmbed))
v.Sym.Def = asTypesNode(v)
v.Name.Param.Ntype = typ
v.SetClass(PEXTERN)
externdcl = append(externdcl, v)
exprs = []*Node{v}
}
v.Name.Param.SetEmbedFiles(list)
embedlist = append(embedlist, v)
return exprs
}
// embedKindApprox determines the kind of embedding variable, approximately.
// The match is approximate because we haven't done scope resolution yet and
// can't tell whether "string" and "byte" really mean "string" and "byte".
// The result must be confirmed later, after type checking, using embedKind.
func embedKindApprox(typ *Node) int {
if typ.Sym != nil && typ.Sym.Name == "FS" && (typ.Sym.Pkg.Path == "embed" || (typ.Sym.Pkg == localpkg && myimportpath == "embed")) {
return embedFiles
}
// These are not guaranteed to match only string and []byte -
// maybe the local package has redefined one of those words.
// But it's the best we can do now during the noder.
// The stricter check happens later, in initEmbed calling embedKind.
if typ.Sym != nil && typ.Sym.Name == "string" && typ.Sym.Pkg == localpkg {
return embedString
}
if typ.Op == OTARRAY && typ.Left == nil && typ.Right.Sym != nil && typ.Right.Sym.Name == "byte" && typ.Right.Sym.Pkg == localpkg {
return embedBytes
}
return embedUnknown
}
// 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 == types.Types[TSTRING] {
return embedString
}
if typ.Sym == nil && typ.IsSlice() && typ.Elem() == types.Bytetype {
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) {
files := v.Name.Param.EmbedFiles()
switch kind := embedKind(v.Type); kind {
case embedUnknown:
yyerrorl(v.Pos, "go:embed cannot apply to var of type %v", v.Type)
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)
}
}

8
src/cmd/compile/internal/gc/main.go
View File

@ -34,8 +34,6 @@ import (
"strings"
)
var imported_unsafe bool
var (
buildid string
spectre string
@ -240,6 +238,7 @@ func Main(archInit func(*Arch)) {
flag.BoolVar(&flagDWARF, "dwarf", !Wasm, "generate DWARF symbols")
flag.BoolVar(&Ctxt.Flag_locationlists, "dwarflocationlists", true, "add location lists to DWARF in optimized mode")
flag.IntVar(&genDwarfInline, "gendwarfinl", 2, "generate DWARF inline info records")
objabi.Flagfn1("embedcfg", "read go:embed configuration from `file`", readEmbedCfg)
objabi.Flagfn1("importmap", "add `definition` of the form source=actual to import map", addImportMap)
objabi.Flagfn1("importcfg", "read import configuration from `file`", readImportCfg)
flag.StringVar(&flag_installsuffix, "installsuffix", "", "set pkg directory `suffix`")
@ -597,7 +596,7 @@ func Main(archInit func(*Arch)) {
timings.Start("fe", "typecheck", "top1")
for i := 0; i < len(xtop); i++ {
n := xtop[i]
if op := n.Op; op != ODCL && op != OAS && op != OAS2 && (op != ODCLTYPE || !n.Left.Name.Param.Alias) {
if op := n.Op; op != ODCL && op != OAS && op != OAS2 && (op != ODCLTYPE || !n.Left.Name.Param.Alias()) {
xtop[i] = typecheck(n, ctxStmt)
}
}
@ -609,7 +608,7 @@ func Main(archInit func(*Arch)) {
timings.Start("fe", "typecheck", "top2")
for i := 0; i < len(xtop); i++ {
n := xtop[i]
if op := n.Op; op == ODCL || op == OAS || op == OAS2 || op == ODCLTYPE && n.Left.Name.Param.Alias {
if op := n.Op; op == ODCL || op == OAS || op == OAS2 || op == ODCLTYPE && n.Left.Name.Param.Alias() {
xtop[i] = typecheck(n, ctxStmt)
}
}
@ -1177,7 +1176,6 @@ func importfile(f *Val) *types.Pkg {
}
if path_ == "unsafe" {
imported_unsafe = true
return unsafepkg
}

145
src/cmd/compile/internal/gc/noder.go
View File

@ -11,6 +11,7 @@ import (
"runtime"
"strconv"
"strings"
"unicode"
"unicode/utf8"
"cmd/compile/internal/syntax"
@ -90,7 +91,11 @@ func (p *noder) makeSrcPosBase(b0 *syntax.PosBase) *src.PosBase {
} else {
// line directive base
p0 := b0.Pos()
p1 := src.MakePos(p.makeSrcPosBase(p0.Base()), p0.Line(), p0.Col())
p0b := p0.Base()
if p0b == b0 {
panic("infinite recursion in makeSrcPosBase")
}
p1 := src.MakePos(p.makeSrcPosBase(p0b), p0.Line(), p0.Col())
b1 = src.NewLinePragmaBase(p1, fn, fileh(fn), b0.Line(), b0.Col())
}
p.basemap[b0] = b1
@ -130,11 +135,13 @@ type noder struct {
base *src.PosBase
}
file *syntax.File
linknames []linkname
pragcgobuf [][]string
err chan syntax.Error
scope ScopeID
file *syntax.File
linknames []linkname
pragcgobuf [][]string
err chan syntax.Error
scope ScopeID
importedUnsafe bool
importedEmbed bool
// scopeVars is a stack tracking the number of variables declared in the
// current function at the moment each open scope was opened.
@ -236,7 +243,8 @@ type linkname struct {
func (p *noder) node() {
types.Block = 1
imported_unsafe = false
p.importedUnsafe = false
p.importedEmbed = false
p.setlineno(p.file.PkgName)
mkpackage(p.file.PkgName.Value)
@ -249,7 +257,7 @@ func (p *noder) node() {
xtop = append(xtop, p.decls(p.file.DeclList)...)
for _, n := range p.linknames {
if !imported_unsafe {
if !p.importedUnsafe {
p.yyerrorpos(n.pos, "//go:linkname only allowed in Go files that import \"unsafe\"")
continue
}
@ -324,7 +332,6 @@ func (p *noder) importDecl(imp *syntax.ImportDecl) {
val := p.basicLit(imp.Path)
ipkg := importfile(&val)
if ipkg == nil {
if nerrors == 0 {
Fatalf("phase error in import")
@ -332,6 +339,13 @@ func (p *noder) importDecl(imp *syntax.ImportDecl) {
return
}
if ipkg == unsafepkg {
p.importedUnsafe = true
}
if ipkg.Path == "embed" {
p.importedEmbed = true
}
ipkg.Direct = true
var my *types.Sym
@ -373,6 +387,20 @@ func (p *noder) varDecl(decl *syntax.VarDecl) []*Node {
}
if pragma, ok := decl.Pragma.(*Pragma); ok {
if len(pragma.Embeds) > 0 {
if !p.importedEmbed {
// This check can't be done when building the list pragma.Embeds
// because that list is created before the noder starts walking over the file,
// so at that point it hasn't seen the imports.
// We're left to check now, just before applying the //go:embed lines.
for _, e := range pragma.Embeds {
p.yyerrorpos(e.Pos, "//go:embed only allowed in Go files that import \"embed\"")
}
} else {
exprs = varEmbed(p, names, typ, exprs, pragma.Embeds)
}
pragma.Embeds = nil
}
p.checkUnused(pragma)
}
@ -455,17 +483,17 @@ func (p *noder) typeDecl(decl *syntax.TypeDecl) *Node {
param := n.Name.Param
param.Ntype = typ
param.Alias = decl.Alias
param.SetAlias(decl.Alias)
if pragma, ok := decl.Pragma.(*Pragma); ok {
if !decl.Alias {
param.Pragma = pragma.Flag & TypePragmas
param.SetPragma(pragma.Flag & TypePragmas)
pragma.Flag &^= TypePragmas
}
p.checkUnused(pragma)
}
nod := p.nod(decl, ODCLTYPE, n, nil)
if param.Alias && !langSupported(1, 9, localpkg) {
if param.Alias() && !langSupported(1, 9, localpkg) {
yyerrorl(nod.Pos, "type aliases only supported as of -lang=go1.9")
}
return nod
@ -1493,13 +1521,15 @@ var allowedStdPragmas = map[string]bool{
"go:cgo_import_dynamic": true,
"go:cgo_ldflag": true,
"go:cgo_dynamic_linker": true,
"go:embed": true,
"go:generate": true,
}
// *Pragma is the value stored in a syntax.Pragma during parsing.
type Pragma struct {
Flag PragmaFlag // collected bits
Pos []PragmaPos // position of each individual flag
Flag PragmaFlag // collected bits
Pos []PragmaPos // position of each individual flag
Embeds []PragmaEmbed
}
type PragmaPos struct {
@ -1507,12 +1537,22 @@ type PragmaPos struct {
Pos syntax.Pos
}
type PragmaEmbed struct {
Pos syntax.Pos
Patterns []string
}
func (p *noder) checkUnused(pragma *Pragma) {
for _, pos := range pragma.Pos {
if pos.Flag&pragma.Flag != 0 {
p.yyerrorpos(pos.Pos, "misplaced compiler directive")
}
}
if len(pragma.Embeds) > 0 {
for _, e := range pragma.Embeds {
p.yyerrorpos(e.Pos, "misplaced go:embed directive")
}
}
}
func (p *noder) checkUnusedDuringParse(pragma *Pragma) {
@ -1521,6 +1561,11 @@ func (p *noder) checkUnusedDuringParse(pragma *Pragma) {
p.error(syntax.Error{Pos: pos.Pos, Msg: "misplaced compiler directive"})
}
}
if len(pragma.Embeds) > 0 {
for _, e := range pragma.Embeds {
p.error(syntax.Error{Pos: e.Pos, Msg: "misplaced go:embed directive"})
}
}
}
// pragma is called concurrently if files are parsed concurrently.
@ -1565,6 +1610,17 @@ func (p *noder) pragma(pos syntax.Pos, blankLine bool, text string, old syntax.P
}
p.linknames = append(p.linknames, linkname{pos, f[1], target})
case text == "go:embed", strings.HasPrefix(text, "go:embed "):
args, err := parseGoEmbed(text[len("go:embed"):])
if err != nil {
p.error(syntax.Error{Pos: pos, Msg: err.Error()})
}
if len(args) == 0 {
p.error(syntax.Error{Pos: pos, Msg: "usage: //go:embed pattern..."})
break
}
pragma.Embeds = append(pragma.Embeds, PragmaEmbed{pos, args})
case strings.HasPrefix(text, "go:cgo_import_dynamic "):
// This is permitted for general use because Solaris
// code relies on it in golang.org/x/sys/unix and others.
@ -1637,3 +1693,64 @@ func mkname(sym *types.Sym) *Node {
}
return n
}
// parseGoEmbed parses the text following "//go:embed" to extract the glob patterns.
// It accepts unquoted space-separated patterns as well as double-quoted and back-quoted Go strings.
// go/build/read.go also processes these strings and contains similar logic.
func parseGoEmbed(args string) ([]string, error) {
var list []string
for args = strings.TrimSpace(args); args != ""; args = strings.TrimSpace(args) {
var path string
Switch:
switch args[0] {
default:
i := len(args)
for j, c := range args {
if unicode.IsSpace(c) {
i = j
break
}
}
path = args[:i]
args = args[i:]
case '`':
i := strings.Index(args[1:], "`")
if i < 0 {
return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
}
path = args[1 : 1+i]
args = args[1+i+1:]
case '"':
i := 1
for ; i < len(args); i++ {
if args[i] == '\\' {
i++
continue
}
if args[i] == '"' {
q, err := strconv.Unquote(args[:i+1])
if err != nil {
return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args[:i+1])
}
path = q
args = args[i+1:]
break Switch
}
}
if i >= len(args) {
return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
}
}
if args != "" {
r, _ := utf8.DecodeRuneInString(args)
if !unicode.IsSpace(r) {
return nil, fmt.Errorf("invalid quoted string in //go:embed: %s", args)
}
}
list = append(list, path)
}
return list, nil
}

132
src/cmd/compile/internal/gc/obj.go
View File

@ -14,6 +14,8 @@ import (
"encoding/json"
"fmt"
"io"
"io/ioutil"
"os"
"sort"
"strconv"
)
@ -125,6 +127,7 @@ func dumpdata() {
itabsLen := len(itabs)
dumpimportstrings()
dumpbasictypes()
dumpembeds()
// Calls to dumpsignats can generate functions,
// like method wrappers and hash and equality routines.
@ -358,28 +361,31 @@ func dbvec(s *obj.LSym, off int, bv bvec) int {
return off
}
const (
stringSymPrefix = "go.string."
stringSymPattern = ".gostring.%d.%x"
)
// stringsym returns a symbol containing the string s.
// The symbol contains the string data, not a string header.
func stringsym(pos src.XPos, s string) (data *obj.LSym) {
var symname string
if len(s) > 100 {
// Huge strings are hashed to avoid long names in object files.
// Indulge in some paranoia by writing the length of s, too,
// as protection against length extension attacks.
// Same pattern is known to fileStringSym below.
h := sha256.New()
io.WriteString(h, s)
symname = fmt.Sprintf(".gostring.%d.%x", len(s), h.Sum(nil))
symname = fmt.Sprintf(stringSymPattern, len(s), h.Sum(nil))
} else {
// Small strings get named directly by their contents.
symname = strconv.Quote(s)
}
const prefix = "go.string."
symdataname := prefix + symname
symdata := Ctxt.Lookup(symdataname)
symdata := Ctxt.Lookup(stringSymPrefix + symname)
if !symdata.OnList() {
// string data
off := dsname(symdata, 0, s, pos, "string")
off := dstringdata(symdata, 0, s, pos, "string")
ggloblsym(symdata, int32(off), obj.DUPOK|obj.RODATA|obj.LOCAL)
symdata.Set(obj.AttrContentAddressable, true)
}
@ -387,26 +393,122 @@ func stringsym(pos src.XPos, s string) (data *obj.LSym) {
return symdata
}
var slicebytes_gen int
// fileStringSym returns a symbol for the contents and the size of file.
// If readonly is true, the symbol shares storage with any literal string
// or other file with the same content and is placed in a read-only section.
// If readonly is false, the symbol is a read-write copy separate from any other,
// for use as the backing store of a []byte.
// The content hash of file is copied into hash. (If hash is nil, nothing is copied.)
// The returned symbol contains the data itself, not a string header.
func fileStringSym(pos src.XPos, file string, readonly bool, hash []byte) (*obj.LSym, int64, error) {
f, err := os.Open(file)
if err != nil {
return nil, 0, err
}
defer f.Close()
info, err := f.Stat()
if err != nil {
return nil, 0, err
}
if !info.Mode().IsRegular() {
return nil, 0, fmt.Errorf("not a regular file")
}
size := info.Size()
if size <= 1*1024 {
data, err := ioutil.ReadAll(f)
if err != nil {
return nil, 0, err
}
if int64(len(data)) != size {
return nil, 0, fmt.Errorf("file changed between reads")
}
var sym *obj.LSym
if readonly {
sym = stringsym(pos, string(data))
} else {
sym = slicedata(pos, string(data)).Sym.Linksym()
}
if len(hash) > 0 {
sum := sha256.Sum256(data)
copy(hash, sum[:])
}
return sym, size, nil
}
if size > 2e9 {
// ggloblsym takes an int32,
// and probably the rest of the toolchain
// can't handle such big symbols either.
// See golang.org/issue/9862.
return nil, 0, fmt.Errorf("file too large")
}
func slicebytes(nam *Node, s string) {
slicebytes_gen++
symname := fmt.Sprintf(".gobytes.%d", slicebytes_gen)
// File is too big to read and keep in memory.
// Compute hash if needed for read-only content hashing or if the caller wants it.
var sum []byte
if readonly || len(hash) > 0 {
h := sha256.New()
n, err := io.Copy(h, f)
if err != nil {
return nil, 0, err
}
if n != size {
return nil, 0, fmt.Errorf("file changed between reads")
}
sum = h.Sum(nil)
copy(hash, sum)
}
var symdata *obj.LSym
if readonly {
symname := fmt.Sprintf(stringSymPattern, size, sum)
symdata = Ctxt.Lookup(stringSymPrefix + symname)
if !symdata.OnList() {
info := symdata.NewFileInfo()
info.Name = file
info.Size = size
ggloblsym(symdata, int32(size), obj.DUPOK|obj.RODATA|obj.LOCAL)
// Note: AttrContentAddressable cannot be set here,
// because the content-addressable-handling code
// does not know about file symbols.
}
} else {
// Emit a zero-length data symbol
// and then fix up length and content to use file.
symdata = slicedata(pos, "").Sym.Linksym()
symdata.Size = size
symdata.Type = objabi.SNOPTRDATA
info := symdata.NewFileInfo()
info.Name = file
info.Size = size
}
return symdata, size, nil
}
var slicedataGen int
func slicedata(pos src.XPos, s string) *Node {
slicedataGen++
symname := fmt.Sprintf(".gobytes.%d", slicedataGen)
sym := localpkg.Lookup(symname)
symnode := newname(sym)
sym.Def = asTypesNode(symnode)
lsym := sym.Linksym()
off := dsname(lsym, 0, s, nam.Pos, "slice")
off := dstringdata(lsym, 0, s, pos, "slice")
ggloblsym(lsym, int32(off), obj.NOPTR|obj.LOCAL)
return symnode
}
func slicebytes(nam *Node, s string) {
if nam.Op != ONAME {
Fatalf("slicebytes %v", nam)
}
slicesym(nam, symnode, int64(len(s)))
slicesym(nam, slicedata(nam.Pos, s), int64(len(s)))
}
func dsname(s *obj.LSym, off int, t string, pos src.XPos, what string) int {
func dstringdata(s *obj.LSym, off int, t string, pos src.XPos, what string) int {
// Objects that are too large will cause the data section to overflow right away,
// causing a cryptic error message by the linker. Check for oversize objects here
// and provide a useful error message instead.

86
src/cmd/compile/internal/gc/syntax.go
View File

@ -480,11 +480,87 @@ type Param struct {
Innermost *Node
Outer *Node
// OTYPE
//
// TODO: Should Func pragmas also be stored on the Name?
Pragma PragmaFlag
Alias bool // node is alias for Ntype (only used when type-checking ODCLTYPE)
// OTYPE & ONAME //go:embed info,
// sharing storage to reduce gc.Param size.
// Extra is nil, or else *Extra is a *paramType or an *embedFileList.
Extra *interface{}
}
type paramType struct {
flag PragmaFlag
alias bool
}
type embedFileList []string
// Pragma returns the PragmaFlag for p, which must be for an OTYPE.
func (p *Param) Pragma() PragmaFlag {
if p.Extra == nil {
return 0
}
return (*p.Extra).(*paramType).flag
}
// SetPragma sets the PragmaFlag for p, which must be for an OTYPE.
func (p *Param) SetPragma(flag PragmaFlag) {
if p.Extra == nil {
if flag == 0 {
return
}
p.Extra = new(interface{})
*p.Extra = &paramType{flag: flag}
return
}
(*p.Extra).(*paramType).flag = flag
}
// Alias reports whether p, which must be for an OTYPE, is a type alias.
func (p *Param) Alias() bool {
if p.Extra == nil {
return false
}
t, ok := (*p.Extra).(*paramType)
if !ok {
return false
}
return t.alias
}
// SetAlias sets whether p, which must be for an OTYPE, is a type alias.
func (p *Param) SetAlias(alias bool) {
if p.Extra == nil {
if !alias {
return
}
p.Extra = new(interface{})
*p.Extra = &paramType{alias: alias}
return
}
(*p.Extra).(*paramType).alias = alias
}
// EmbedFiles returns the list of embedded files for p,
// which must be for an ONAME var.
func (p *Param) EmbedFiles() []string {
if p.Extra == nil {
return nil
}
return *(*p.Extra).(*embedFileList)
}
// SetEmbedFiles sets the list of embedded files for p,
// which must be for an ONAME var.
func (p *Param) SetEmbedFiles(list []string) {
if p.Extra == nil {
if len(list) == 0 {
return
}
f := embedFileList(list)
p.Extra = new(interface{})
*p.Extra = &f
return
}
*(*p.Extra).(*embedFileList) = list
}
// Functions

8
src/cmd/compile/internal/gc/typecheck.go
View File

@ -257,12 +257,12 @@ func typecheck(n *Node, top int) (res *Node) {
// are substituted.
cycle := cycleFor(n)
for _, n1 := range cycle {
if n1.Name != nil && !n1.Name.Param.Alias {
if n1.Name != nil && !n1.Name.Param.Alias() {
// Cycle is ok. But if n is an alias type and doesn't
// have a type yet, we have a recursive type declaration
// with aliases that we can't handle properly yet.
// Report an error rather than crashing later.
if n.Name != nil && n.Name.Param.Alias && n.Type == nil {
if n.Name != nil && n.Name.Param.Alias() && n.Type == nil {
lineno = n.Pos
Fatalf("cannot handle alias type declaration (issue #25838): %v", n)
}
@ -3504,7 +3504,7 @@ func setUnderlying(t, underlying *types.Type) {
}
// Propagate go:notinheap pragma from the Name to the Type.
if n.Name != nil && n.Name.Param != nil && n.Name.Param.Pragma&NotInHeap != 0 {
if n.Name != nil && n.Name.Param != nil && n.Name.Param.Pragma()&NotInHeap != 0 {
t.SetNotInHeap(true)
}
@ -3676,7 +3676,7 @@ func typecheckdef(n *Node) {
n.Name.Defn = typecheck(n.Name.Defn, ctxStmt) // fills in n.Type
case OTYPE:
if p := n.Name.Param; p.Alias {
if p := n.Name.Param; p.Alias() {
// Type alias declaration: Simply use the rhs type - no need
// to create a new type.
// If we have a syntax error, p.Ntype may be nil.

29
src/cmd/internal/obj/link.go
View File

@ -401,7 +401,7 @@ type LSym struct {
P []byte
R []Reloc
Extra *interface{} // *FuncInfo if present
Extra *interface{} // *FuncInfo or *FileInfo, if present
Pkg string
PkgIdx int32
@ -454,6 +454,33 @@ func (s *LSym) Func() *FuncInfo {
return f
}
// A FileInfo contains extra fields for SDATA symbols backed by files.
// (If LSym.Extra is a *FileInfo, LSym.P == nil.)
type FileInfo struct {
Name string // name of file to read into object file
Size int64 // length of file
}
// NewFileInfo allocates and returns a FileInfo for LSym.
func (s *LSym) NewFileInfo() *FileInfo {
if s.Extra != nil {
log.Fatalf("invalid use of LSym - NewFileInfo with Extra of type %T", *s.Extra)
}
f := new(FileInfo)
s.Extra = new(interface{})
*s.Extra = f
return f
}
// File returns the *FileInfo associated with s, or else nil.
func (s *LSym) File() *FileInfo {
if s.Extra == nil {
return nil
}
f, _ := (*s.Extra).(*FileInfo)
return f
}
type InlMark struct {
// When unwinding from an instruction in an inlined body, mark
// where we should unwind to.

49
src/cmd/internal/obj/objfile.go
View File

@ -16,6 +16,8 @@ import (
"encoding/binary"
"fmt"
"io"
"log"
"os"
"path/filepath"
"sort"
"strings"
@ -147,14 +149,20 @@ func WriteObjFile(ctxt *Link, b *bio.Writer) {
// Data indexes
h.Offsets[goobj.BlkDataIdx] = w.Offset()
dataOff := uint32(0)
dataOff := int64(0)
for _, list := range lists {
for _, s := range list {
w.Uint32(dataOff)
dataOff += uint32(len(s.P))
w.Uint32(uint32(dataOff))
dataOff += int64(len(s.P))
if file := s.File(); file != nil {
dataOff += int64(file.Size)
}
}
}
w.Uint32(dataOff)
if int64(uint32(dataOff)) != dataOff {
log.Fatalf("data too large")
}
w.Uint32(uint32(dataOff))
// Relocs
h.Offsets[goobj.BlkReloc] = w.Offset()
@ -179,6 +187,9 @@ func WriteObjFile(ctxt *Link, b *bio.Writer) {
for _, list := range lists {
for _, s := range list {
w.Bytes(s.P)
if file := s.File(); file != nil {
w.writeFile(ctxt, file)
}
}
}
@ -218,6 +229,7 @@ func WriteObjFile(ctxt *Link, b *bio.Writer) {
type writer struct {
*goobj.Writer
filebuf []byte
ctxt *Link
pkgpath string // the package import path (escaped), "" if unknown
pkglist []string // list of packages referenced, indexed by ctxt.pkgIdx
@ -232,6 +244,35 @@ func (w *writer) init() {
}
}
func (w *writer) writeFile(ctxt *Link, file *FileInfo) {
f, err := os.Open(file.Name)
if err != nil {
ctxt.Diag("%v", err)
return
}
defer f.Close()
if w.filebuf == nil {
w.filebuf = make([]byte, 1024)
}
buf := w.filebuf
written := int64(0)
for {
n, err := f.Read(buf)
w.Bytes(buf[:n])
written += int64(n)
if err == io.EOF {
break
}
if err != nil {
ctxt.Diag("%v", err)
return
}
}
if written != file.Size {
ctxt.Diag("copy %s: unexpected length %d != %d", file.Name, written, file.Size)
}
}
func (w *writer) StringTable() {
w.AddString("")
for _, p := range w.ctxt.Imports {