func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_X86_64_PC32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_X86_64_PC32 relocation for dynamic symbol %s", targ.Name)
}
if targ.Type == 0 || targ.Type == obj.SXREF {
ld.Diag("unknown symbol %s in pcrel", targ.Name)
}
r.Type = obj.R_PCREL
r.Add += 4
return
case 256 + ld.R_X86_64_PLT32:
r.Type = obj.R_PCREL
r.Add += 4
if targ.Type == obj.SDYNIMPORT {
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add += int64(targ.Plt)
}
return
case 256 + ld.R_X86_64_GOTPCREL, 256 + ld.R_X86_64_GOTPCRELX, 256 + ld.R_X86_64_REX_GOTPCRELX:
if targ.Type != obj.SDYNIMPORT {
// have symbol
if r.Off >= 2 && s.P[r.Off-2] == 0x8b {
// turn MOVQ of GOT entry into LEAQ of symbol itself
s.P[r.Off-2] = 0x8d
r.Type = obj.R_PCREL
r.Add += 4
return
}
}
// fall back to using GOT and hope for the best (CMOV*)
// TODO: just needs relocation, no need to put in .dynsym
addgotsym(targ)
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += 4
r.Add += int64(targ.Got)
return
case 256 + ld.R_X86_64_64:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_X86_64_64 relocation for dynamic symbol %s", targ.Name)
}
r.Type = obj.R_ADDR
return
// Handle relocations found in Mach-O object files.
case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0,
512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0,
512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0:
// TODO: What is the difference between all these?
r.Type = obj.R_ADDR
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected reloc for dynamic symbol %s", targ.Name)
}
return
case 512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 1:
if targ.Type == obj.SDYNIMPORT {
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
r.Type = obj.R_PCREL
return
}
fallthrough
// fall through
case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED_1*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED_2*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED_4*2 + 1:
r.Type = obj.R_PCREL
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected pc-relative reloc for dynamic symbol %s", targ.Name)
}
return
case 512 + ld.MACHO_X86_64_RELOC_GOT_LOAD*2 + 1:
if targ.Type != obj.SDYNIMPORT {
// have symbol
// turn MOVQ of GOT entry into LEAQ of symbol itself
if r.Off < 2 || s.P[r.Off-2] != 0x8b {
ld.Diag("unexpected GOT_LOAD reloc for non-dynamic symbol %s", targ.Name)
return
}
s.P[r.Off-2] = 0x8d
r.Type = obj.R_PCREL
return
}
fallthrough
// fall through
case 512 + ld.MACHO_X86_64_RELOC_GOT*2 + 1:
if targ.Type != obj.SDYNIMPORT {
ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
}
addgotsym(targ)
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got)
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
switch r.Type {
case obj.R_CALL,
obj.R_PCREL:
if ld.HEADTYPE == obj.Hwindows {
// nothing to do, the relocation will be laid out in pereloc1
return
} else {
// for both ELF and Mach-O
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
return
}
case obj.R_ADDR:
if s.Type == obj.STEXT && ld.Iself {
if ld.HEADTYPE == obj.Hsolaris {
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add += int64(targ.Plt)
return
}
// The code is asking for the address of an external
// function. We provide it with the address of the
// correspondent GOT symbol.
addgotsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got)
return
}
if s.Type != obj.SDATA {
break
}
if ld.Iself {
ld.Adddynsym(ld.Ctxt, targ)
rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
if r.Siz == 8 {
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_X86_64_64))
} else {
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_X86_64_32))
}
ld.Adduint64(ld.Ctxt, rela, uint64(r.Add))
r.Type = 256 // ignore during relocsym
return
}
if ld.HEADTYPE == obj.Hdarwin && s.Size == int64(ld.Thearch.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(ld.Ctxt, targ)
got := ld.Linklookup(ld.Ctxt, ".got", 0)
s.Type = got.Type | obj.SSUB
s.Outer = got
s.Sub = got.Sub
got.Sub = s
s.Value = got.Size
ld.Adduint64(ld.Ctxt, got, 0)
ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(targ.Dynid))
r.Type = 256 // ignore during relocsym
return
}
if ld.HEADTYPE == obj.Hwindows {
// nothing to do, the relocation will be laid out in pereloc1
return
}
}
ld.Ctxt.Cursym = s
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_ARM_PLT32:
r.Type = obj.R_CALLARM
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
}
return
case 256 + ld.R_ARM_THM_PC22: // R_ARM_THM_CALL
ld.Exitf("R_ARM_THM_CALL, are you using -marm?")
return
case 256 + ld.R_ARM_GOT32: // R_ARM_GOT_BREL
if targ.Type != obj.SDYNIMPORT {
addgotsyminternal(ld.Ctxt, targ)
} else {
addgotsym(ld.Ctxt, targ)
}
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
r.Add += int64(targ.Got)
return
case 256 + ld.R_ARM_GOT_PREL: // GOT(nil) + A - nil
if targ.Type != obj.SDYNIMPORT {
addgotsyminternal(ld.Ctxt, targ)
} else {
addgotsym(ld.Ctxt, targ)
}
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got) + 4
return
case 256 + ld.R_ARM_GOTOFF: // R_ARM_GOTOFF32
r.Type = obj.R_GOTOFF
return
case 256 + ld.R_ARM_GOTPC: // R_ARM_BASE_PREL
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += 4
return
case 256 + ld.R_ARM_CALL:
r.Type = obj.R_CALLARM
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
}
return
case 256 + ld.R_ARM_REL32: // R_ARM_REL32
r.Type = obj.R_PCREL
r.Add += 4
return
case 256 + ld.R_ARM_ABS32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_ARM_ABS32 relocation for dynamic symbol %s", targ.Name)
}
r.Type = obj.R_ADDR
return
// we can just ignore this, because we are targeting ARM V5+ anyway
case 256 + ld.R_ARM_V4BX:
if r.Sym != nil {
// R_ARM_V4BX is ABS relocation, so this symbol is a dummy symbol, ignore it
r.Sym.Type = 0
}
r.Sym = nil
return
case 256 + ld.R_ARM_PC24,
256 + ld.R_ARM_JUMP24:
r.Type = obj.R_CALLARM
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
}
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
switch r.Type {
case obj.R_CALLARM:
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
return
case obj.R_ADDR:
if s.Type != obj.SDATA {
break
}
if ld.Iself {
ld.Adddynsym(ld.Ctxt, targ)
rel := ld.Linklookup(ld.Ctxt, ".rel", 0)
ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
ld.Adduint32(ld.Ctxt, rel, ld.ELF32_R_INFO(uint32(targ.Dynid), ld.R_ARM_GLOB_DAT)) // we need a nil + A dynamic reloc
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
return
}
}
ld.Ctxt.Cursym = s
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_386_PC32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_386_PC32 relocation for dynamic symbol %s", targ.Name)
}
if targ.Type == 0 || targ.Type == obj.SXREF {
ld.Diag("unknown symbol %s in pcrel", targ.Name)
}
r.Type = obj.R_PCREL
r.Add += 4
return
case 256 + ld.R_386_PLT32:
r.Type = obj.R_PCREL
r.Add += 4
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add += int64(targ.Plt)
}
return
case 256 + ld.R_386_GOT32, 256 + ld.R_386_GOT32X:
if targ.Type != obj.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 = obj.R_GOTOFF
return
}
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 = obj.R_ADDR
return
}
ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
return
}
addgotsym(ld.Ctxt, targ)
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
r.Add += int64(targ.Got)
return
case 256 + ld.R_386_GOTOFF:
r.Type = obj.R_GOTOFF
return
case 256 + ld.R_386_GOTPC:
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += 4
return
case 256 + ld.R_386_32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_386_32 relocation for dynamic symbol %s", targ.Name)
}
r.Type = obj.R_ADDR
return
case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 0:
r.Type = obj.R_ADDR
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected reloc for dynamic symbol %s", targ.Name)
}
return
case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 1:
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
r.Type = obj.R_PCREL
return
}
r.Type = obj.R_PCREL
return
case 512 + ld.MACHO_FAKE_GOTPCREL:
if targ.Type != obj.SDYNIMPORT {
// have symbol
// turn MOVL of GOT entry into LEAL of symbol itself
if r.Off < 2 || s.P[r.Off-2] != 0x8b {
ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
return
}
s.P[r.Off-2] = 0x8d
r.Type = obj.R_PCREL
return
}
addgotsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got)
r.Type = obj.R_PCREL
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
switch r.Type {
case obj.R_CALL,
obj.R_PCREL:
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
return
case obj.R_ADDR:
if s.Type != obj.SDATA {
break
}
if ld.Iself {
ld.Adddynsym(ld.Ctxt, targ)
rel := ld.Linklookup(ld.Ctxt, ".rel", 0)
ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
ld.Adduint32(ld.Ctxt, rel, ld.ELF32_R_INFO(uint32(targ.Dynid), ld.R_386_32))
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
return
}
if ld.HEADTYPE == obj.Hdarwin && s.Size == 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(ld.Ctxt, targ)
got := ld.Linklookup(ld.Ctxt, ".got", 0)
s.Type = got.Type | obj.SSUB
s.Outer = got
s.Sub = got.Sub
got.Sub = s
s.Value = got.Size
ld.Adduint32(ld.Ctxt, got, 0)
ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(targ.Dynid))
r.Type = 256 // ignore during relocsym
return
}
if ld.HEADTYPE == obj.Hwindows && s.Size == PtrSize {
// nothing to do, the relocation will be laid out in pereloc1
return
}
}
ld.Ctxt.Cursym = s
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_PPC64_REL24:
r.Type = obj.R_CALLPOWER
// This is a local call, so the caller isn't setting
// up r12 and r2 is the same for the caller and
// callee. Hence, we need to go to the local entry
// point. (If we don't do this, the callee will try
// to use r12 to compute r2.)
r.Add += int64(r.Sym.Localentry) * 4
if targ.Type == obj.SDYNIMPORT {
// Should have been handled in elfsetupplt
ld.Diag("unexpected R_PPC64_REL24 for dyn import")
}
return
case 256 + ld.R_PPC_REL32:
r.Type = obj.R_PCREL
r.Add += 4
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_PPC_REL32 for dyn import")
}
return
case 256 + ld.R_PPC64_ADDR64:
r.Type = obj.R_ADDR
if targ.Type == obj.SDYNIMPORT {
// These happen in .toc sections
ld.Adddynsym(ld.Ctxt, targ)
rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_PPC64_ADDR64))
ld.Adduint64(ld.Ctxt, rela, uint64(r.Add))
r.Type = 256 // ignore during relocsym
}
return
case 256 + ld.R_PPC64_TOC16:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_LO | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_LO:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_LO
return
case 256 + ld.R_PPC64_TOC16_HA:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_HA | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_HI:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_HI | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_DS:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_DS | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_LO_DS:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_DS
return
case 256 + ld.R_PPC64_REL16_LO:
r.Type = obj.R_PCREL
r.Variant = ld.RV_POWER_LO
r.Add += 2 // Compensate for relocation size of 2
return
case 256 + ld.R_PPC64_REL16_HI:
r.Type = obj.R_PCREL
r.Variant = ld.RV_POWER_HI | ld.RV_CHECK_OVERFLOW
r.Add += 2
return
case 256 + ld.R_PPC64_REL16_HA:
r.Type = obj.R_PCREL
r.Variant = ld.RV_POWER_HA | ld.RV_CHECK_OVERFLOW
r.Add += 2
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
// TODO(austin): Translate our relocations to ELF
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}