package obj
import (
- "bufio"
"cmd/internal/bio"
"cmd/internal/dwarf"
"cmd/internal/objabi"
"cmd/internal/sys"
"fmt"
- "log"
- "path/filepath"
"sort"
- "strings"
"sync"
)
-// objWriter writes Go object files.
-type objWriter struct {
- wr *bufio.Writer
- ctxt *Link
- // Temporary buffer for zigzag int writing.
- varintbuf [10]uint8
-
- // Number of objects written of each type.
- nRefs int
- nData int
- nReloc int
- nPcdata int
- nFuncdata int
- nFile int
-
- pkgpath string // the package import path (escaped), "" if unknown
-}
-
-func (w *objWriter) addLengths(s *LSym) {
- w.nData += len(s.P)
- w.nReloc += len(s.R)
-
- if s.Type != objabi.STEXT {
- return
- }
-
- pc := &s.Func.Pcln
-
- data := 0
- data += len(pc.Pcsp.P)
- data += len(pc.Pcfile.P)
- data += len(pc.Pcline.P)
- data += len(pc.Pcinline.P)
- for _, pcd := range pc.Pcdata {
- data += len(pcd.P)
- }
-
- w.nData += data
- w.nPcdata += len(pc.Pcdata)
-
- w.nFuncdata += len(pc.Funcdataoff)
- w.nFile += len(pc.File)
-}
-
-func (w *objWriter) writeLengths() {
- w.writeInt(int64(w.nData))
- w.writeInt(int64(w.nReloc))
- w.writeInt(int64(w.nPcdata))
- w.writeInt(int64(0)) // TODO: remove at next object file rev
- w.writeInt(int64(w.nFuncdata))
- w.writeInt(int64(w.nFile))
-}
-
-func newObjWriter(ctxt *Link, b *bufio.Writer, pkgpath string) *objWriter {
- return &objWriter{
- ctxt: ctxt,
- wr: b,
- pkgpath: objabi.PathToPrefix(pkgpath),
- }
-}
-
func WriteObjFile(ctxt *Link, bout *bio.Writer, pkgpath string) {
- if ctxt.Flag_newobj {
- WriteObjFile2(ctxt, bout, pkgpath)
- return
- }
-
- b := bout.Writer
- w := newObjWriter(ctxt, b, pkgpath)
-
- // Magic header
- w.wr.WriteString("\x00go114ld")
-
- // Version
- w.wr.WriteByte(1)
-
- // Autolib
- for _, pkg := range ctxt.Imports {
- w.writeString(pkg)
- }
- w.writeString("")
-
- // DWARF File Table
- fileTable := ctxt.PosTable.DebugLinesFileTable()
- w.writeInt(int64(len(fileTable)))
- for _, str := range fileTable {
- w.writeString(str)
- }
-
- // Symbol references
- for _, s := range ctxt.Text {
- w.writeRefs(s)
- w.addLengths(s)
- }
-
- if ctxt.Headtype == objabi.Haix {
- // Data must be sorted to keep a constant order in TOC symbols.
- // As they are created during Progedit, two symbols can be switched between
- // two different compilations. Therefore, BuildID will be different.
- // TODO: find a better place and optimize to only sort TOC symbols
- sort.Slice(ctxt.Data, func(i, j int) bool {
- return ctxt.Data[i].Name < ctxt.Data[j].Name
- })
- }
-
- for _, s := range ctxt.Data {
- w.writeRefs(s)
- w.addLengths(s)
- }
- for _, s := range ctxt.ABIAliases {
- w.writeRefs(s)
- w.addLengths(s)
- }
- // End symbol references
- w.wr.WriteByte(0xff)
-
- // Lengths
- w.writeLengths()
-
- // Data block
- for _, s := range ctxt.Text {
- w.wr.Write(s.P)
- pc := &s.Func.Pcln
- w.wr.Write(pc.Pcsp.P)
- w.wr.Write(pc.Pcfile.P)
- w.wr.Write(pc.Pcline.P)
- w.wr.Write(pc.Pcinline.P)
- for _, pcd := range pc.Pcdata {
- w.wr.Write(pcd.P)
- }
- }
- for _, s := range ctxt.Data {
- if len(s.P) > 0 {
- switch s.Type {
- case objabi.SBSS, objabi.SNOPTRBSS, objabi.STLSBSS:
- ctxt.Diag("cannot provide data for %v sym %v", s.Type, s.Name)
- }
- }
- w.wr.Write(s.P)
- }
-
- // Symbols
- for _, s := range ctxt.Text {
- w.writeSym(s)
- }
- for _, s := range ctxt.Data {
- w.writeSym(s)
- }
- for _, s := range ctxt.ABIAliases {
- w.writeSym(s)
- }
-
- // Magic footer
- w.wr.WriteString("\xffgo114ld")
-}
-
-// Symbols are prefixed so their content doesn't get confused with the magic footer.
-const symPrefix = 0xfe
-
-func (w *objWriter) writeRef(s *LSym, isPath bool) {
- if s == nil || s.RefIdx != 0 {
- return
- }
- w.wr.WriteByte(symPrefix)
- if isPath {
- w.writeString(filepath.ToSlash(s.Name))
- } else if w.pkgpath != "" {
- // w.pkgpath is already escaped.
- n := strings.Replace(s.Name, "\"\".", w.pkgpath+".", -1)
- w.writeString(n)
- } else {
- w.writeString(s.Name)
- }
- // Write ABI/static information.
- abi := int64(s.ABI())
- if s.Static() {
- abi = -1
- }
- w.writeInt(abi)
- w.nRefs++
- s.RefIdx = w.nRefs
-}
-
-func (w *objWriter) writeRefs(s *LSym) {
- w.writeRef(s, false)
- w.writeRef(s.Gotype, false)
- for _, r := range s.R {
- w.writeRef(r.Sym, false)
- }
-
- if s.Type == objabi.STEXT {
- pc := &s.Func.Pcln
- for _, d := range pc.Funcdata {
- w.writeRef(d, false)
- }
- for _, f := range pc.File {
- fsym := w.ctxt.Lookup(f)
- w.writeRef(fsym, true)
- }
- for _, call := range pc.InlTree.nodes {
- w.writeRef(call.Func, false)
- f, _ := linkgetlineFromPos(w.ctxt, call.Pos)
- fsym := w.ctxt.Lookup(f)
- w.writeRef(fsym, true)
- }
- }
+ WriteObjFile2(ctxt, bout, pkgpath)
}
func (ctxt *Link) writeSymDebug(s *LSym) {
}
}
-func (w *objWriter) writeSym(s *LSym) {
- ctxt := w.ctxt
- if ctxt.Debugasm > 0 {
- w.ctxt.writeSymDebug(s)
- }
-
- w.wr.WriteByte(symPrefix)
- w.wr.WriteByte(byte(s.Type))
- w.writeRefIndex(s)
- flags := int64(0)
- if s.DuplicateOK() {
- flags |= 1
- }
- if s.Local() {
- flags |= 1 << 1
- }
- if s.MakeTypelink() {
- flags |= 1 << 2
- }
- w.writeInt(flags)
- w.writeInt(s.Size)
- w.writeRefIndex(s.Gotype)
- w.writeInt(int64(len(s.P)))
-
- w.writeInt(int64(len(s.R)))
- var r *Reloc
- for i := range s.R {
- r = &s.R[i]
- w.writeInt(int64(r.Off))
- w.writeInt(int64(r.Siz))
- w.writeInt(int64(r.Type))
- w.writeInt(r.Add)
- w.writeRefIndex(r.Sym)
- }
-
- if s.Type != objabi.STEXT {
- return
- }
-
- w.writeInt(int64(s.Func.Args))
- w.writeInt(int64(s.Func.Locals))
- w.writeBool(s.NoSplit())
- flags = int64(0)
- if s.Leaf() {
- flags |= 1
- }
- if s.CFunc() {
- flags |= 1 << 1
- }
- if s.ReflectMethod() {
- flags |= 1 << 2
- }
- if ctxt.Flag_shared {
- flags |= 1 << 3
- }
- if s.TopFrame() {
- flags |= 1 << 4
- }
- w.writeInt(flags)
- w.writeInt(int64(0)) // TODO: remove at next object file rev
-
- pc := &s.Func.Pcln
- w.writeInt(int64(len(pc.Pcsp.P)))
- w.writeInt(int64(len(pc.Pcfile.P)))
- w.writeInt(int64(len(pc.Pcline.P)))
- w.writeInt(int64(len(pc.Pcinline.P)))
- w.writeInt(int64(len(pc.Pcdata)))
- for _, pcd := range pc.Pcdata {
- w.writeInt(int64(len(pcd.P)))
- }
- w.writeInt(int64(len(pc.Funcdataoff)))
- for i := range pc.Funcdataoff {
- w.writeRefIndex(pc.Funcdata[i])
- }
- for i := range pc.Funcdataoff {
- w.writeInt(pc.Funcdataoff[i])
- }
- w.writeInt(int64(len(pc.File)))
- for _, f := range pc.File {
- fsym := ctxt.Lookup(f)
- w.writeRefIndex(fsym)
- }
- w.writeInt(int64(len(pc.InlTree.nodes)))
- for _, call := range pc.InlTree.nodes {
- w.writeInt(int64(call.Parent))
- f, l := linkgetlineFromPos(w.ctxt, call.Pos)
- fsym := ctxt.Lookup(f)
- w.writeRefIndex(fsym)
- w.writeInt(int64(l))
- w.writeRefIndex(call.Func)
- w.writeInt(int64(call.ParentPC))
- }
-}
-
-func (w *objWriter) writeBool(b bool) {
- if b {
- w.writeInt(1)
- } else {
- w.writeInt(0)
- }
-}
-
-func (w *objWriter) writeInt(sval int64) {
- var v uint64
- uv := (uint64(sval) << 1) ^ uint64(sval>>63)
- p := w.varintbuf[:]
- for v = uv; v >= 0x80; v >>= 7 {
- p[0] = uint8(v | 0x80)
- p = p[1:]
- }
- p[0] = uint8(v)
- p = p[1:]
- w.wr.Write(w.varintbuf[:len(w.varintbuf)-len(p)])
-}
-
-func (w *objWriter) writeString(s string) {
- w.writeInt(int64(len(s)))
- w.wr.WriteString(s)
-}
-
-func (w *objWriter) writeRefIndex(s *LSym) {
- if s == nil {
- w.writeInt(0)
- return
- }
- if s.RefIdx == 0 {
- log.Fatalln("writing an unreferenced symbol", s.Name)
- }
- w.writeInt(int64(s.RefIdx))
-}
-
// relocByOff sorts relocations by their offsets.
type relocByOff []Reloc