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llvm-svn: 263799
This commit is contained in:
Rafael Espindola 2016-03-18 18:09:32 +00:00
parent 5b5061f0ca
commit c2cfd9fa34
4 changed files with 19 additions and 105 deletions
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96
lld/ELF/InputSection.cpp
View File

@ -215,89 +215,10 @@ static uintX_t getMipsGotVA(const SymbolBody &Body, uintX_t SymVA,
return Body.getGotVA<ELFT>();
}
template <class ELFT>
template <class RelTy>
void InputSectionBase<ELFT>::relocate(uint8_t *Buf, uint8_t *BufEnd,
iterator_range<const RelTy *> Rels) {
size_t Num = Rels.end() - Rels.begin();
for (size_t I = 0; I < Num; ++I) {
const RelTy &RI = *(Rels.begin() + I);
uintX_t Offset = getOffset(RI.r_offset);
if (Offset == (uintX_t)-1)
continue;
uintX_t A = getAddend<ELFT>(RI);
uint32_t SymIndex = RI.getSymbol(Config->Mips64EL);
uint32_t Type = RI.getType(Config->Mips64EL);
uint8_t *BufLoc = Buf + Offset;
uintX_t AddrLoc = OutSec->getVA() + Offset;
if (Target->pointsToLocalDynamicGotEntry(Type) &&
!Target->canRelaxTls(Type, nullptr)) {
Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc,
Out<ELFT>::Got->getTlsIndexVA() + A);
continue;
}
SymbolBody &Body = File->getSymbolBody(SymIndex).repl();
if (Target->canRelaxTls(Type, &Body)) {
uintX_t SymVA;
if (Target->needsGot(Type, Body))
SymVA = Body.getGotVA<ELFT>();
else
SymVA = Body.getVA<ELFT>();
// By optimizing TLS relocations, it is sometimes needed to skip
// relocations that immediately follow TLS relocations. This function
// knows how many slots we need to skip.
I += Target->relaxTls(BufLoc, BufEnd, Type, AddrLoc, SymVA, Body);
continue;
}
// PPC64 has a special relocation representing the TOC base pointer
// that does not have a corresponding symbol.
if (Config->EMachine == EM_PPC64 && RI.getType(false) == R_PPC64_TOC) {
uintX_t SymVA = getPPC64TocBase() + A;
Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc, SymVA, 0);
continue;
}
if (Target->isTlsGlobalDynamicRel(Type) &&
!Target->canRelaxTls(Type, &Body)) {
Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc,
Out<ELFT>::Got->getGlobalDynAddr(Body) + A);
continue;
}
uintX_t SymVA = Body.getVA<ELFT>(A);
uint8_t *PairedLoc = nullptr;
if (Config->EMachine == EM_MIPS)
PairedLoc = findMipsPairedReloc(Buf, &RI, Rels.end());
if (Target->needsPlt<ELFT>(Type, Body)) {
SymVA = Body.getPltVA<ELFT>() + A;
} else if (Target->needsGot(Type, Body)) {
if (Config->EMachine == EM_MIPS)
SymVA = getMipsGotVA<ELFT>(Body, SymVA, BufLoc, PairedLoc) + A;
else
SymVA = Body.getGotVA<ELFT>() + A;
if (Body.IsTls)
Type = Target->getTlsGotRel(Type);
} else if (Target->isSizeRel(Type) && Body.isPreemptible()) {
// A SIZE relocation is supposed to set a symbol size, but if a symbol
// can be preempted, the size at runtime may be different than link time.
// If that's the case, we leave the field alone rather than filling it
// with a possibly incorrect value.
continue;
} else if (Config->EMachine == EM_MIPS) {
SymVA = adjustMipsSymVA<ELFT>(Type, *File, Body, AddrLoc, SymVA) + A;
} else if (!Target->needsCopyRel<ELFT>(Type, Body) &&
Body.isPreemptible()) {
continue;
}
uintX_t Size = Body.getSize<ELFT>();
Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc, SymVA, Size + A,
PairedLoc);
template <class ELFT> void InputSectionBase<ELFT>::relocate(uint8_t *Buf) {
for (const Relocation &Rel : Relocations) {
uint8_t *Pos = Buf + Rel.Offset;
*(uint64_t *)Pos = Rel.Sym->getVA<ELFT>(0);
}
}
@ -321,14 +242,7 @@ template <class ELFT> void InputSection<ELFT>::writeTo(uint8_t *Buf) {
memcpy(Buf + OutSecOff, Data.data(), Data.size());
uint8_t *BufEnd = Buf + OutSecOff + Data.size();
// Iterate over all relocation sections that apply to this section.
for (const Elf_Shdr *RelSec : this->RelocSections) {
if (RelSec->sh_type == SHT_RELA)
this->relocate(Buf, BufEnd, EObj.relas(RelSec));
else
this->relocate(Buf, BufEnd, EObj.rels(RelSec));
}
this->relocate(Buf);
}
template <class ELFT>

11
lld/ELF/InputSection.h
View File

@ -23,6 +23,12 @@ template <class ELFT> class ObjectFile;
template <class ELFT> class OutputSection;
template <class ELFT> class OutputSectionBase;
struct Relocation {
enum RelType { R_64 } Type;
uint64_t Offset;
SymbolBody *Sym;
};
// This corresponds to a section of an input file.
template <class ELFT> class InputSectionBase {
protected:
@ -75,9 +81,8 @@ public:
InputSectionBase<ELFT> *getRelocTarget(const Elf_Rel &Rel) const;
InputSectionBase<ELFT> *getRelocTarget(const Elf_Rela &Rel) const;
template <class RelTy>
void relocate(uint8_t *Buf, uint8_t *BufEnd,
llvm::iterator_range<const RelTy *> Rels);
void relocate(uint8_t *Buf);
std::vector<Relocation> Relocations;
private:
template <class RelTy>

12
lld/ELF/OutputSections.cpp
View File

@ -1168,16 +1168,8 @@ template <class ELFT> void EHOutputSection<ELFT>::writeTo(uint8_t *Buf) {
}
}
for (EHInputSection<ELFT> *S : Sections) {
const Elf_Shdr *RelSec = S->RelocSection;
if (!RelSec)
continue;
ELFFile<ELFT> &EObj = S->getFile()->getObj();
if (RelSec->sh_type == SHT_RELA)
S->relocate(Buf, nullptr, EObj.relas(RelSec));
else
S->relocate(Buf, nullptr, EObj.rels(RelSec));
}
for (EHInputSection<ELFT> *S : Sections)
S->relocate(Buf);
}
template <class ELFT>

5
lld/ELF/Writer.cpp
View File

@ -466,8 +466,11 @@ void Writer<ELFT>::scanRelocs(InputSectionBase<ELFT> &C,
// We can however do better than just copying the incoming relocation. We
// can process some of it and and just ask the dynamic linker to add the
// load address.
if (!Config->Pic || Target->isRelRelative(Type) || Target->isSizeRel(Type))
if (!Config->Pic || Target->isRelRelative(Type) ||
Target->isSizeRel(Type)) {
C.Relocations.push_back({Relocation::R_64, RI.r_offset, &Body});
continue;
}
uintX_t Addend = getAddend<ELFT>(RI);
if (Config->EMachine == EM_PPC64 && RI.getType(false) == R_PPC64_TOC) {