Golang程序
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// Inferno utils/8l/asm.c
// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/8l/asm.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package x86
import (
"cmd/internal/objabi"
"cmd/internal/sys"
"cmd/link/internal/ld"
"cmd/link/internal/sym"
"debug/elf"
"log"
)
// Append 4 bytes to s and create a R_CALL relocation targeting t to fill them in.
func addcall(ctxt *ld.Link, s *sym.Symbol, t *sym.Symbol) {
s.Attr |= sym.AttrReachable
i := s.Size
s.Size += 4
s.Grow(s.Size)
r := s.AddRel()
r.Sym = t
r.Off = int32(i)
r.Type = objabi.R_CALL
r.Siz = 4
}
func gentext(ctxt *ld.Link) {
if ctxt.DynlinkingGo() {
// We need get_pc_thunk.
} else {
switch ctxt.BuildMode {
case ld.BuildModeCArchive:
if !ctxt.IsELF {
return
}
case ld.BuildModePIE, ld.BuildModeCShared, ld.BuildModePlugin:
// We need get_pc_thunk.
default:
return
}
}
// Generate little thunks that load the PC of the next instruction into a register.
thunks := make([]*sym.Symbol, 0, 7+len(ctxt.Textp))
for _, r := range [...]struct {
name string
num uint8
}{
{"ax", 0},
{"cx", 1},
{"dx", 2},
{"bx", 3},
// sp
{"bp", 5},
{"si", 6},
{"di", 7},
} {
thunkfunc := ctxt.Syms.Lookup("__x86.get_pc_thunk."+r.name, 0)
thunkfunc.Type = sym.STEXT
thunkfunc.Attr |= sym.AttrLocal
thunkfunc.Attr |= sym.AttrReachable //TODO: remove?
o := func(op ...uint8) {
for _, op1 := range op {
thunkfunc.AddUint8(op1)
}
}
// 8b 04 24 mov (%esp),%eax
// Destination register is in bits 3-5 of the middle byte, so add that in.
o(0x8b, 0x04+r.num<<3, 0x24)
// c3 ret
o(0xc3)
thunks = append(thunks, thunkfunc)
}
ctxt.Textp = append(thunks, ctxt.Textp...) // keep Textp in dependency order
addmoduledata := ctxt.Syms.Lookup("runtime.addmoduledata", 0)
if addmoduledata.Type == sym.STEXT && ctxt.BuildMode != ld.BuildModePlugin {
// we're linking a module containing the runtime -> no need for
// an init function
return
}
addmoduledata.Attr |= sym.AttrReachable
initfunc := ctxt.Syms.Lookup("go.link.addmoduledata", 0)
initfunc.Type = sym.STEXT
initfunc.Attr |= sym.AttrLocal
initfunc.Attr |= sym.AttrReachable
o := func(op ...uint8) {
for _, op1 := range op {
initfunc.AddUint8(op1)
}
}
// go.link.addmoduledata:
// 53 push %ebx
// e8 00 00 00 00 call __x86.get_pc_thunk.cx + R_CALL __x86.get_pc_thunk.cx
// 8d 81 00 00 00 00 lea 0x0(%ecx), %eax + R_PCREL ctxt.Moduledata
// 8d 99 00 00 00 00 lea 0x0(%ecx), %ebx + R_GOTPC _GLOBAL_OFFSET_TABLE_
// e8 00 00 00 00 call runtime.addmoduledata@plt + R_CALL runtime.addmoduledata
// 5b pop %ebx
// c3 ret
o(0x53)
o(0xe8)
addcall(ctxt, initfunc, ctxt.Syms.Lookup("__x86.get_pc_thunk.cx", 0))
o(0x8d, 0x81)
initfunc.AddPCRelPlus(ctxt.Arch, ctxt.Moduledata, 6)
o(0x8d, 0x99)
i := initfunc.Size
initfunc.Size += 4
initfunc.Grow(initfunc.Size)
r := initfunc.AddRel()
r.Sym = ctxt.Syms.Lookup("_GLOBAL_OFFSET_TABLE_", 0)
r.Off = int32(i)
r.Type = objabi.R_PCREL
r.Add = 12
r.Siz = 4
o(0xe8)
addcall(ctxt, initfunc, addmoduledata)
o(0x5b)
o(0xc3)
if ctxt.BuildMode == ld.BuildModePlugin {
ctxt.Textp = append(ctxt.Textp, addmoduledata)
}
ctxt.Textp = append(ctxt.Textp, initfunc)
initarray_entry := ctxt.Syms.Lookup("go.link.addmoduledatainit", 0)
initarray_entry.Attr |= sym.AttrReachable
initarray_entry.Attr |= sym.AttrLocal
initarray_entry.Type = sym.SINITARR
initarray_entry.AddAddr(ctxt.Arch, initfunc)
}
func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
targ := r.Sym
switch r.Type {
default:
if r.Type >= 256 {
ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, sym.RelocName(ctxt.Arch, r.Type))
return false
}
// Handle relocations found in ELF object files.
case 256 + objabi.RelocType(elf.R_386_PC32):
if targ.Type == sym.SDYNIMPORT {
ld.Errorf(s, "unexpected R_386_PC32 relocation for dynamic symbol %s", targ.Name)
}
// TODO(mwhudson): the test of VisibilityHidden here probably doesn't make
// sense and should be removed when someone has thought about it properly.
if (targ.Type == 0 || targ.Type == sym.SXREF) && !targ.Attr.VisibilityHidden() {
ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name)
}
r.Type = objabi.R_PCREL
r.Add += 4
return true
case 256 + objabi.RelocType(elf.R_386_PLT32):
r.Type = objabi.R_PCREL
r.Add += 4
if targ.Type == sym.SDYNIMPORT {
addpltsym(ctxt, targ)
r.Sym = ctxt.Syms.Lookup(".plt", 0)
r.Add += int64(targ.Plt)
}
return true
case 256 + objabi.RelocType(elf.R_386_GOT32), 256 + objabi.RelocType(elf.R_386_GOT32X):
if targ.Type != sym.SDYNIMPORT {
// have symbol
if r.Off >= 2 && s.P[r.Off-2] == 0x8b {
// turn MOVL of GOT entry into LEAL of symbol address, relative to GOT.
s.P[r.Off-2] = 0x8d
r.Type = objabi.R_GOTOFF
return true
}
if r.Off >= 2 && s.P[r.Off-2] == 0xff && s.P[r.Off-1] == 0xb3 {
// turn PUSHL of GOT entry into PUSHL of symbol itself.
// use unnecessary SS prefix to keep instruction same length.
s.P[r.Off-2] = 0x36
s.P[r.Off-1] = 0x68
r.Type = objabi.R_ADDR
return true
}
ld.Errorf(s, "unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
return false
}
addgotsym(ctxt, targ)
r.Type = objabi.R_CONST // write r->add during relocsym
r.Sym = nil
r.Add += int64(targ.Got)
return true
case 256 + objabi.RelocType(elf.R_386_GOTOFF):
r.Type = objabi.R_GOTOFF
return true
case 256 + objabi.RelocType(elf.R_386_GOTPC):
r.Type = objabi.R_PCREL
r.Sym = ctxt.Syms.Lookup(".got", 0)
r.Add += 4
return true
case 256 + objabi.RelocType(elf.R_386_32):
if targ.Type == sym.SDYNIMPORT {
ld.Errorf(s, "unexpected R_386_32 relocation for dynamic symbol %s", targ.Name)
}
r.Type = objabi.R_ADDR
return true
case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 0:
r.Type = objabi.R_ADDR
if targ.Type == sym.SDYNIMPORT {
ld.Errorf(s, "unexpected reloc for dynamic symbol %s", targ.Name)
}
return true
case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 1:
if targ.Type == sym.SDYNIMPORT {
addpltsym(ctxt, targ)
r.Sym = ctxt.Syms.Lookup(".plt", 0)
r.Add = int64(targ.Plt)
r.Type = objabi.R_PCREL
return true
}
r.Type = objabi.R_PCREL
return true
case 512 + ld.MACHO_FAKE_GOTPCREL:
if targ.Type != sym.SDYNIMPORT {
// have symbol
// turn MOVL of GOT entry into LEAL of symbol itself
if r.Off < 2 || s.P[r.Off-2] != 0x8b {
ld.Errorf(s, "unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
return false
}
s.P[r.Off-2] = 0x8d
r.Type = objabi.R_PCREL
return true
}
addgotsym(ctxt, targ)
r.Sym = ctxt.Syms.Lookup(".got", 0)
r.Add += int64(targ.Got)
r.Type = objabi.R_PCREL
return true
}
// Handle references to ELF symbols from our own object files.
if targ.Type != sym.SDYNIMPORT {
return true
}
switch r.Type {
case objabi.R_CALL,
objabi.R_PCREL:
addpltsym(ctxt, targ)
r.Sym = ctxt.Syms.Lookup(".plt", 0)
r.Add = int64(targ.Plt)
return true
case objabi.R_ADDR:
if s.Type != sym.SDATA {
break
}
if ctxt.IsELF {
ld.Adddynsym(ctxt, targ)
rel := ctxt.Syms.Lookup(".rel", 0)
rel.AddAddrPlus(ctxt.Arch, s, int64(r.Off))
rel.AddUint32(ctxt.Arch, ld.ELF32_R_INFO(uint32(targ.Dynid), uint32(elf.R_386_32)))
r.Type = objabi.R_CONST // write r->add during relocsym
r.Sym = nil
return true
}
if ctxt.HeadType == objabi.Hdarwin && s.Size == int64(ctxt.Arch.PtrSize) && r.Off == 0 {
// Mach-O relocations are a royal pain to lay out.
// They use a compact stateful bytecode representation
// that is too much bother to deal with.
// Instead, interpret the C declaration
// void *_Cvar_stderr = &stderr;
// as making _Cvar_stderr the name of a GOT entry
// for stderr. This is separate from the usual GOT entry,
// just in case the C code assigns to the variable,
// and of course it only works for single pointers,
// but we only need to support cgo and that's all it needs.
ld.Adddynsym(ctxt, targ)
got := ctxt.Syms.Lookup(".got", 0)
s.Type = got.Type
s.Attr |= sym.AttrSubSymbol
s.Outer = got
s.Sub = got.Sub
got.Sub = s
s.Value = got.Size
got.AddUint32(ctxt.Arch, 0)
ctxt.Syms.Lookup(".linkedit.got", 0).AddUint32(ctxt.Arch, uint32(targ.Dynid))
r.Type = 256 // ignore during relocsym
return true
}
}
return false
}
func elfreloc1(ctxt *ld.Link, r *sym.Reloc, sectoff int64) bool {
ctxt.Out.Write32(uint32(sectoff))
elfsym := r.Xsym.ElfsymForReloc()
switch r.Type {
default:
return false
case objabi.R_ADDR:
if r.Siz == 4 {
ctxt.Out.Write32(uint32(elf.R_386_32) | uint32(elfsym)<<8)
} else {
return false
}
case objabi.R_GOTPCREL:
if r.Siz == 4 {
ctxt.Out.Write32(uint32(elf.R_386_GOTPC))
if r.Xsym.Name != "_GLOBAL_OFFSET_TABLE_" {
ctxt.Out.Write32(uint32(sectoff))
ctxt.Out.Write32(uint32(elf.R_386_GOT32) | uint32(elfsym)<<8)
}
} else {
return false
}
case objabi.R_CALL:
if r.Siz == 4 {
if r.Xsym.Type == sym.SDYNIMPORT {
ctxt.Out.Write32(uint32(elf.R_386_PLT32) | uint32(elfsym)<<8)
} else {
ctxt.Out.Write32(uint32(elf.R_386_PC32) | uint32(elfsym)<<8)
}
} else {
return false
}
case objabi.R_PCREL:
if r.Siz == 4 {
ctxt.Out.Write32(uint32(elf.R_386_PC32) | uint32(elfsym)<<8)
} else {
return false
}
case objabi.R_TLS_LE:
if r.Siz == 4 {
ctxt.Out.Write32(uint32(elf.R_386_TLS_LE) | uint32(elfsym)<<8)
} else {
return false
}
case objabi.R_TLS_IE:
if r.Siz == 4 {
ctxt.Out.Write32(uint32(elf.R_386_GOTPC))
ctxt.Out.Write32(uint32(sectoff))
ctxt.Out.Write32(uint32(elf.R_386_TLS_GOTIE) | uint32(elfsym)<<8)
} else {
return false
}
}
return true
}
func machoreloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool {
var v uint32
rs := r.Xsym
if rs.Type == sym.SHOSTOBJ {
if rs.Dynid < 0 {
ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Type, rs.Type)
return false
}
v = uint32(rs.Dynid)
v |= 1 << 27 // external relocation
} else {
v = uint32(rs.Sect.Extnum)
if v == 0 {
ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Sect.Name, rs.Type, rs.Type)
return false
}
}
switch r.Type {
default:
return false
case objabi.R_ADDR:
v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28
case objabi.R_CALL,
objabi.R_PCREL:
v |= 1 << 24 // pc-relative bit
v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28
}
switch r.Siz {
default:
return false
case 1:
v |= 0 << 25
case 2:
v |= 1 << 25
case 4:
v |= 2 << 25
case 8:
v |= 3 << 25
}
out.Write32(uint32(sectoff))
out.Write32(v)
return true
}
func pereloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool {
var v uint32
rs := r.Xsym
if rs.Dynid < 0 {
ld.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Type, rs.Type)
return false
}
out.Write32(uint32(sectoff))
out.Write32(uint32(rs.Dynid))
switch r.Type {
default:
return false
case objabi.R_DWARFSECREF:
v = ld.IMAGE_REL_I386_SECREL
case objabi.R_ADDR:
v = ld.IMAGE_REL_I386_DIR32
case objabi.R_CALL,
objabi.R_PCREL:
v = ld.IMAGE_REL_I386_REL32
}
out.Write16(uint16(v))
return true
}
func archreloc(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val *int64) bool {
if ctxt.LinkMode == ld.LinkExternal {
return false
}
switch r.Type {
case objabi.R_CONST:
*val = r.Add
return true
case objabi.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ctxt.Syms.Lookup(".got", 0))
return true
}
return false
}
func archrelocvariant(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, t int64) int64 {
log.Fatalf("unexpected relocation variant")
return t
}
func elfsetupplt(ctxt *ld.Link) {
plt := ctxt.Syms.Lookup(".plt", 0)
got := ctxt.Syms.Lookup(".got.plt", 0)
if plt.Size == 0 {
// pushl got+4
plt.AddUint8(0xff)
plt.AddUint8(0x35)
plt.AddAddrPlus(ctxt.Arch, got, 4)
// jmp *got+8
plt.AddUint8(0xff)
plt.AddUint8(0x25)
plt.AddAddrPlus(ctxt.Arch, got, 8)
// zero pad
plt.AddUint32(ctxt.Arch, 0)
// assume got->size == 0 too
got.AddAddrPlus(ctxt.Arch, ctxt.Syms.Lookup(".dynamic", 0), 0)
got.AddUint32(ctxt.Arch, 0)
got.AddUint32(ctxt.Arch, 0)
}
}
func addpltsym(ctxt *ld.Link, s *sym.Symbol) {
if s.Plt >= 0 {
return
}
ld.Adddynsym(ctxt, s)
if ctxt.IsELF {
plt := ctxt.Syms.Lookup(".plt", 0)
got := ctxt.Syms.Lookup(".got.plt", 0)
rel := ctxt.Syms.Lookup(".rel.plt", 0)
if plt.Size == 0 {
elfsetupplt(ctxt)
}
// jmpq *got+size
plt.AddUint8(0xff)
plt.AddUint8(0x25)
plt.AddAddrPlus(ctxt.Arch, got, got.Size)
// add to got: pointer to current pos in plt
got.AddAddrPlus(ctxt.Arch, plt, plt.Size)
// pushl $x
plt.AddUint8(0x68)
plt.AddUint32(ctxt.Arch, uint32(rel.Size))
// jmp .plt
plt.AddUint8(0xe9)
plt.AddUint32(ctxt.Arch, uint32(-(plt.Size + 4)))
// rel
rel.AddAddrPlus(ctxt.Arch, got, got.Size-4)
rel.AddUint32(ctxt.Arch, ld.ELF32_R_INFO(uint32(s.Dynid), uint32(elf.R_386_JMP_SLOT)))
s.Plt = int32(plt.Size - 16)
} else if ctxt.HeadType == objabi.Hdarwin {
// Same laziness as in 6l.
plt := ctxt.Syms.Lookup(".plt", 0)
addgotsym(ctxt, s)
ctxt.Syms.Lookup(".linkedit.plt", 0).AddUint32(ctxt.Arch, uint32(s.Dynid))
// jmpq *got+size(IP)
s.Plt = int32(plt.Size)
plt.AddUint8(0xff)
plt.AddUint8(0x25)
plt.AddAddrPlus(ctxt.Arch, ctxt.Syms.Lookup(".got", 0), int64(s.Got))
} else {
ld.Errorf(s, "addpltsym: unsupported binary format")
}
}
func addgotsym(ctxt *ld.Link, s *sym.Symbol) {
if s.Got >= 0 {
return
}
ld.Adddynsym(ctxt, s)
got := ctxt.Syms.Lookup(".got", 0)
s.Got = int32(got.Size)
got.AddUint32(ctxt.Arch, 0)
if ctxt.IsELF {
rel := ctxt.Syms.Lookup(".rel", 0)
rel.AddAddrPlus(ctxt.Arch, got, int64(s.Got))
rel.AddUint32(ctxt.Arch, ld.ELF32_R_INFO(uint32(s.Dynid), uint32(elf.R_386_GLOB_DAT)))
} else if ctxt.HeadType == objabi.Hdarwin {
ctxt.Syms.Lookup(".linkedit.got", 0).AddUint32(ctxt.Arch, uint32(s.Dynid))
} else {
ld.Errorf(s, "addgotsym: unsupported binary format")
}
}
func asmb(ctxt *ld.Link) {
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f asmb\n", ld.Cputime())
}
if ctxt.IsELF {
ld.Asmbelfsetup()
}
sect := ld.Segtext.Sections[0]
ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
// 0xCC is INT $3 - breakpoint instruction
ld.CodeblkPad(ctxt, int64(sect.Vaddr), int64(sect.Length), []byte{0xCC})
for _, sect = range ld.Segtext.Sections[1:] {
ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
ld.Datblk(ctxt, int64(sect.Vaddr), int64(sect.Length))
}
if ld.Segrodata.Filelen > 0 {
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f rodatblk\n", ld.Cputime())
}
ctxt.Out.SeekSet(int64(ld.Segrodata.Fileoff))
ld.Datblk(ctxt, int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen))
}
if ld.Segrelrodata.Filelen > 0 {
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f relrodatblk\n", ld.Cputime())
}
ctxt.Out.SeekSet(int64(ld.Segrelrodata.Fileoff))
ld.Datblk(ctxt, int64(ld.Segrelrodata.Vaddr), int64(ld.Segrelrodata.Filelen))
}
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f datblk\n", ld.Cputime())
}
ctxt.Out.SeekSet(int64(ld.Segdata.Fileoff))
ld.Datblk(ctxt, int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen))
ctxt.Out.SeekSet(int64(ld.Segdwarf.Fileoff))
ld.Dwarfblk(ctxt, int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen))
machlink := uint32(0)
if ctxt.HeadType == objabi.Hdarwin {
machlink = uint32(ld.Domacholink(ctxt))
}
ld.Symsize = 0
ld.Spsize = 0
ld.Lcsize = 0
symo := uint32(0)
if !*ld.FlagS {
// TODO: rationalize
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f sym\n", ld.Cputime())
}
switch ctxt.HeadType {
default:
if ctxt.IsELF {
symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
symo = uint32(ld.Rnd(int64(symo), int64(*ld.FlagRound)))
}
case objabi.Hplan9:
symo = uint32(ld.Segdata.Fileoff + ld.Segdata.Filelen)
case objabi.Hdarwin:
symo = uint32(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(*ld.FlagRound))) + uint64(machlink))
case objabi.Hwindows:
symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
symo = uint32(ld.Rnd(int64(symo), ld.PEFILEALIGN))
}
ctxt.Out.SeekSet(int64(symo))
switch ctxt.HeadType {
default:
if ctxt.IsELF {
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f elfsym\n", ld.Cputime())
}
ld.Asmelfsym(ctxt)
ctxt.Out.Flush()
ctxt.Out.Write(ld.Elfstrdat)
if ctxt.LinkMode == ld.LinkExternal {
ld.Elfemitreloc(ctxt)
}
}
case objabi.Hplan9:
ld.Asmplan9sym(ctxt)
ctxt.Out.Flush()
sym := ctxt.Syms.Lookup("pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
ctxt.Out.Write(sym.P)
ctxt.Out.Flush()
}
case objabi.Hwindows:
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f dwarf\n", ld.Cputime())
}
case objabi.Hdarwin:
if ctxt.LinkMode == ld.LinkExternal {
ld.Machoemitreloc(ctxt)
}
}
}
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f headr\n", ld.Cputime())
}
ctxt.Out.SeekSet(0)
switch ctxt.HeadType {
default:
case objabi.Hplan9: /* plan9 */
magic := int32(4*11*11 + 7)
ctxt.Out.Write32b(uint32(magic)) /* magic */
ctxt.Out.Write32b(uint32(ld.Segtext.Filelen)) /* sizes */
ctxt.Out.Write32b(uint32(ld.Segdata.Filelen))
ctxt.Out.Write32b(uint32(ld.Segdata.Length - ld.Segdata.Filelen))
ctxt.Out.Write32b(uint32(ld.Symsize)) /* nsyms */
ctxt.Out.Write32b(uint32(ld.Entryvalue(ctxt))) /* va of entry */
ctxt.Out.Write32b(uint32(ld.Spsize)) /* sp offsets */
ctxt.Out.Write32b(uint32(ld.Lcsize)) /* line offsets */
case objabi.Hdarwin:
ld.Asmbmacho(ctxt)
case objabi.Hlinux,
objabi.Hfreebsd,
objabi.Hnetbsd,
objabi.Hopenbsd,
objabi.Hnacl:
ld.Asmbelf(ctxt, int64(symo))
case objabi.Hwindows:
ld.Asmbpe(ctxt)
}
ctxt.Out.Flush()
}