[dev.link] cmd/compile, cmd/asm: delete old object file format support

There are more cleanups to do, but I want to keep this CL mostly
a pure deletion.

Change-Id: Icd2ff0a4b648eb4adf3d29386542617e49620818
Reviewed-on: https://go-review.googlesource.com/c/go/+/206398
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Cherry Zhang 2019-11-11 14:49:37 -05:00
parent aacffb6576
commit 181faef82c
8 changed files with 19 additions and 370 deletions

View file

@ -7,225 +7,17 @@
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) {
@ -305,137 +97,6 @@ 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