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Simplify got handling. 

Each getRelExpr is now expected to return the correct got expression
instead of having Writer patch it up with needsGot.

llvm-svn: 266466
This commit is contained in:
Rafael Espindola 2016-04-15 19:14:18 +00:00
parent f9f1c5619a
commit 5628ee7631
3 changed files with 25 additions and 80 deletions
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85
lld/ELF/Target.cpp
View File

@ -86,7 +86,6 @@ public:
bool isRelRelative(uint32_t Type) const override;
bool needsCopyRelImpl(uint32_t Type) const override;
bool needsDynRelative(uint32_t Type) const override;
bool needsGot(uint32_t Type, const SymbolBody &S) const override;
bool needsPltImpl(uint32_t Type) const override;
void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
@ -115,7 +114,6 @@ public:
void writePlt(uint8_t *Buf, uint64_t GotEntryAddr, uint64_t PltEntryAddr,
int32_t Index, unsigned RelOff) const override;
bool needsCopyRelImpl(uint32_t Type) const override;
bool needsGot(uint32_t Type, const SymbolBody &S) const override;
bool refersToGotEntry(uint32_t Type) const override;
bool needsPltImpl(uint32_t Type) const override;
void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
@ -141,7 +139,6 @@ public:
RelExpr getRelExpr(uint32_t Type, const SymbolBody &S) const override;
void writePlt(uint8_t *Buf, uint64_t GotEntryAddr, uint64_t PltEntryAddr,
int32_t Index, unsigned RelOff) const override;
bool needsGot(uint32_t Type, const SymbolBody &S) const override;
bool needsPltImpl(uint32_t Type) const override;
void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
bool isRelRelative(uint32_t Type) const override;
@ -161,7 +158,6 @@ public:
uint32_t getTlsGotRel(uint32_t Type) const override;
bool isRelRelative(uint32_t Type) const override;
bool needsCopyRelImpl(uint32_t Type) const override;
bool needsGot(uint32_t Type, const SymbolBody &S) const override;
bool refersToGotEntry(uint32_t Type) const override;
bool needsPltImpl(uint32_t Type) const override;
void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
@ -192,7 +188,6 @@ public:
void writeGotHeader(uint8_t *Buf) const override;
void writeThunk(uint8_t *Buf, uint64_t S) const override;
bool needsCopyRelImpl(uint32_t Type) const override;
bool needsGot(uint32_t Type, const SymbolBody &S) const override;
bool needsPltImpl(uint32_t Type) const override;
bool needsThunk(uint32_t Type, const InputFile &File,
const SymbolBody &S) const override;
@ -282,10 +277,6 @@ bool TargetInfo::isGotRelative(uint32_t Type) const { return false; }
bool TargetInfo::isHintRel(uint32_t Type) const { return false; }
bool TargetInfo::isRelRelative(uint32_t Type) const { return true; }
bool TargetInfo::needsGot(uint32_t Type, const SymbolBody &S) const {
return false;
}
bool TargetInfo::needsPltImpl(uint32_t Type) const { return false; }
bool TargetInfo::refersToGotEntry(uint32_t Type) const { return false; }
@ -385,6 +376,10 @@ RelExpr X86TargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
case R_386_PC32:
case R_386_GOTPC:
return R_PC;
case R_386_GOT32:
case R_386_TLS_GOTIE:
case R_386_TLS_IE:
return R_GOT;
}
}
@ -486,14 +481,6 @@ bool X86TargetInfo::needsCopyRelImpl(uint32_t Type) const {
return Type == R_386_32 || Type == R_386_16 || Type == R_386_8;
}
bool X86TargetInfo::needsGot(uint32_t Type, const SymbolBody &S) const {
if (S.isTls() && Type == R_386_TLS_GD)
return Target->canRelaxTls(Type, &S) && S.isPreemptible();
if (Type == R_386_TLS_GOTIE || Type == R_386_TLS_IE)
return !canRelaxTls(Type, &S);
return Type == R_386_GOT32 || needsPlt(Type, S);
}
bool X86TargetInfo::needsPltImpl(uint32_t Type) const {
return Type == R_386_PLT32;
}
@ -689,13 +676,16 @@ RelExpr X86_64TargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
case R_X86_64_SIZE32:
case R_X86_64_SIZE64:
return R_SIZE;
case R_X86_64_GOTPCREL:
case R_X86_64_PLT32:
case R_X86_64_PC32:
case R_X86_64_TLSLD:
case R_X86_64_GOTTPOFF:
case R_X86_64_TLSGD:
return R_PC;
case R_X86_64_GOT32:
return R_GOT;
case R_X86_64_GOTPCREL:
case R_X86_64_GOTTPOFF:
return R_GOT_PC;
}
}
@ -746,14 +736,6 @@ bool X86_64TargetInfo::refersToGotEntry(uint32_t Type) const {
Type == R_X86_64_REX_GOTPCRELX;
}
bool X86_64TargetInfo::needsGot(uint32_t Type, const SymbolBody &S) const {
if (Type == R_X86_64_TLSGD)
return Target->canRelaxTls(Type, &S) && S.isPreemptible();
if (Type == R_X86_64_GOTTPOFF)
return !canRelaxTls(Type, &S);
return refersToGotEntry(Type) || needsPlt(Type, S);
}
uint32_t X86_64TargetInfo::getDynRel(uint32_t Type) const {
if (Type == R_X86_64_PC32 || Type == R_X86_64_32)
if (Config->Shared)
@ -1058,22 +1040,6 @@ void PPC64TargetInfo::writePlt(uint8_t *Buf, uint64_t GotEntryAddr,
write32be(Buf + 28, 0x4e800420); // bctr
}
bool PPC64TargetInfo::needsGot(uint32_t Type, const SymbolBody &S) const {
if (needsPlt(Type, S))
return true;
switch (Type) {
default: return false;
case R_PPC64_GOT16:
case R_PPC64_GOT16_DS:
case R_PPC64_GOT16_HA:
case R_PPC64_GOT16_HI:
case R_PPC64_GOT16_LO:
case R_PPC64_GOT16_LO_DS:
return true;
}
}
bool PPC64TargetInfo::needsPltImpl(uint32_t Type) const {
// These are function calls that need to be redirected through a PLT stub.
return Type == R_PPC64_REL24;
@ -1210,10 +1176,14 @@ RelExpr AArch64TargetInfo::getRelExpr(uint32_t Type,
case R_AARCH64_ADR_PREL_LO21:
case R_AARCH64_TSTBR14:
return R_PC;
case R_AARCH64_ADR_GOT_PAGE:
case R_AARCH64_ADR_PREL_PG_HI21:
case R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
return R_PAGE_PC;
case R_AARCH64_LD64_GOT_LO12_NC:
case R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
return R_GOT;
case R_AARCH64_ADR_GOT_PAGE:
case R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
return R_GOT_PAGE_PC;
}
}
@ -1337,19 +1307,6 @@ bool AArch64TargetInfo::needsCopyRelImpl(uint32_t Type) const {
}
}
bool AArch64TargetInfo::needsGot(uint32_t Type, const SymbolBody &S) const {
switch (Type) {
case R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
return !canRelaxTls(Type, &S);
case R_AARCH64_ADR_GOT_PAGE:
case R_AARCH64_LD64_GOT_LO12_NC:
return true;
default:
return needsPlt(Type, S);
}
}
bool AArch64TargetInfo::refersToGotEntry(uint32_t Type) const {
return Type == R_AARCH64_ADR_GOT_PAGE || Type == R_AARCH64_LD64_GOT_LO12_NC;
}
@ -1591,6 +1548,13 @@ RelExpr MipsTargetInfo<ELFT>::getRelExpr(uint32_t Type,
case R_MIPS_PCHI16:
case R_MIPS_PCLO16:
return R_PC;
case R_MIPS_GOT16:
case R_MIPS_CALL16:
if (S.isLocal())
return R_MIPS_GOT_LOCAL;
if (!S.isPreemptible())
return R_MIPS_GOT;
return R_GOT;
}
}
@ -1718,11 +1682,6 @@ bool MipsTargetInfo<ELFT>::needsCopyRelImpl(uint32_t Type) const {
return !isRelRelative(Type) || Type == R_MIPS_LO16;
}
template <class ELFT>
bool MipsTargetInfo<ELFT>::needsGot(uint32_t Type, const SymbolBody &S) const {
return needsPlt(Type, S) || refersToGotEntry(Type);
}
template <class ELFT>
bool MipsTargetInfo<ELFT>::refersToGotEntry(uint32_t Type) const {
return Type == R_MIPS_GOT16 || Type == R_MIPS_CALL16;

1
lld/ELF/Target.h
View File

@ -57,7 +57,6 @@ public:
virtual bool isRelRelative(uint32_t Type) const;
virtual bool needsDynRelative(uint32_t Type) const { return false; }
virtual bool needsGot(uint32_t Type, const SymbolBody &S) const;
virtual bool refersToGotEntry(uint32_t Type) const;
enum PltNeed { Plt_No, Plt_Explicit, Plt_Implicit };

19
lld/ELF/Writer.cpp
View File

@ -563,23 +563,10 @@ void Writer<ELFT>::scanRelocs(InputSectionBase<ELFT> &C, ArrayRef<RelTy> Rels) {
}
// If a relocation needs GOT, we create a GOT slot for the symbol.
if (Target->needsGot(Type, Body)) {
if (Expr == R_GOT || Expr == R_MIPS_GOT || Expr == R_MIPS_GOT_LOCAL ||
Expr == R_GOT_PAGE_PC || Expr == R_GOT_PC) {
uint32_t T = Body.isTls() ? Target->getTlsGotRel(Type) : Type;
RelExpr E;
if (Expr == R_PC)
E = R_GOT_PC;
else if (Expr == R_PAGE_PC)
E = R_GOT_PAGE_PC;
else if (Config->EMachine == EM_MIPS) {
if (Body.isLocal())
E = R_MIPS_GOT_LOCAL;
else if (!Body.isPreemptible())
E = R_MIPS_GOT;
else
E = R_GOT;
} else
E = R_GOT;
C.Relocations.push_back({E, T, Offset, Addend, &Body});
C.Relocations.push_back({Expr, T, Offset, Addend, &Body});
if (Body.isInGot())
continue;
Out<ELFT>::Got->addEntry(Body);