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-rw-r--r--llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp132
1 files changed, 16 insertions, 116 deletions
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
index ce763367e29..f933962d664 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
@@ -21,17 +21,6 @@
using namespace llvm;
namespace {
- struct RelEntry {
- RelEntry(const ELFRelocationEntry &R, const MCSymbol *S, int64_t O) :
- Reloc(R), Sym(S), Offset(O) {}
- ELFRelocationEntry Reloc;
- const MCSymbol *Sym;
- int64_t Offset;
- };
-
- typedef std::list<RelEntry> RelLs;
- typedef RelLs::iterator RelLsIter;
-
class MipsELFObjectWriter : public MCELFObjectTargetWriter {
public:
MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI,
@@ -41,13 +30,7 @@ namespace {
unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
bool IsPCRel) const override;
- virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
- const MCValue &Target,
- const MCFragment &F,
- const MCFixup &Fixup,
- bool IsPCRel) const;
- virtual void sortRelocs(const MCAssembler &Asm,
- std::vector<ELFRelocationEntry> &Relocs);
+ bool needsRelocateWithSymbol(unsigned Type) const override;
};
}
@@ -59,21 +42,6 @@ MipsELFObjectWriter::MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI,
MipsELFObjectWriter::~MipsELFObjectWriter() {}
-const MCSymbol *MipsELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
- const MCValue &Target,
- const MCFragment &F,
- const MCFixup &Fixup,
- bool IsPCRel) const {
- assert(Target.getSymA() && "SymA cannot be 0.");
- const MCSymbol &Sym = Target.getSymA()->getSymbol().AliasedSymbol();
-
- if (Sym.getSection().getKind().isMergeableCString() ||
- Sym.getSection().getKind().isMergeableConst())
- return &Sym;
-
- return NULL;
-}
-
unsigned MipsELFObjectWriter::GetRelocType(const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel) const {
@@ -229,91 +197,23 @@ unsigned MipsELFObjectWriter::GetRelocType(const MCValue &Target,
return Type;
}
-// Return true if R is either a GOT16 against a local symbol or HI16.
-static bool NeedsMatchingLo(const MCAssembler &Asm, const RelEntry &R) {
- if (!R.Sym)
- return false;
-
- MCSymbolData &SD = Asm.getSymbolData(R.Sym->AliasedSymbol());
-
- return ((R.Reloc.Type == ELF::R_MIPS_GOT16) && !SD.isExternal()) ||
- (R.Reloc.Type == ELF::R_MIPS_HI16);
-}
-
-static bool HasMatchingLo(const MCAssembler &Asm, RelLsIter I, RelLsIter Last) {
- if (I == Last)
+bool
+MipsELFObjectWriter::needsRelocateWithSymbol(unsigned Type) const {
+ // FIXME: This is extremelly conservative. This really needs to use a
+ // whitelist with a clear explanation for why each realocation needs to
+ // point to the symbol, not to the section.
+ switch (Type) {
+ default:
+ return true;
+
+ case ELF::R_MIPS_26:
+ case ELF::R_MIPS_LO16:
+ case ELF::R_MIPS_HI16:
+ case ELF::R_MIPS_32:
+ case ELF::R_MIPS_64:
+ case ELF::R_MIPS_GPREL16:
return false;
-
- RelLsIter Hi = I++;
-
- return (I->Reloc.Type == ELF::R_MIPS_LO16) && (Hi->Sym == I->Sym) &&
- (Hi->Offset == I->Offset);
-}
-
-static bool HasSameSymbol(const RelEntry &R0, const RelEntry &R1) {
- return R0.Sym == R1.Sym;
-}
-
-static int CompareOffset(const RelEntry &R0, const RelEntry &R1) {
- return (R0.Offset > R1.Offset) ? 1 : ((R0.Offset == R1.Offset) ? 0 : -1);
-}
-
-void MipsELFObjectWriter::sortRelocs(const MCAssembler &Asm,
- std::vector<ELFRelocationEntry> &Relocs) {
- // Call the default function first. Relocations are sorted in descending
- // order of r_offset.
- MCELFObjectTargetWriter::sortRelocs(Asm, Relocs);
-
- RelLs RelocLs;
- std::vector<RelLsIter> Unmatched;
-
- // Fill RelocLs. Traverse Relocs backwards so that relocations in RelocLs
- // are in ascending order of r_offset.
- for (std::vector<ELFRelocationEntry>::reverse_iterator R = Relocs.rbegin();
- R != Relocs.rend(); ++R) {
- std::pair<const MCSymbolRefExpr*, int64_t> P =
- MipsGetSymAndOffset(*R->Fixup);
- RelocLs.push_back(RelEntry(*R, P.first ? &P.first->getSymbol() : 0,
- P.second));
}
-
- // Get list of unmatched HI16 and GOT16.
- for (RelLsIter R = RelocLs.begin(); R != RelocLs.end(); ++R)
- if (NeedsMatchingLo(Asm, *R) && !HasMatchingLo(Asm, R, --RelocLs.end()))
- Unmatched.push_back(R);
-
- // Insert unmatched HI16 and GOT16 immediately before their matching LO16.
- for (std::vector<RelLsIter>::iterator U = Unmatched.begin();
- U != Unmatched.end(); ++U) {
- RelLsIter LoPos = RelocLs.end(), HiPos = *U;
- bool MatchedLo = false;
-
- for (RelLsIter R = RelocLs.begin(); R != RelocLs.end(); ++R) {
- if ((R->Reloc.Type == ELF::R_MIPS_LO16) && HasSameSymbol(*HiPos, *R) &&
- (CompareOffset(*R, *HiPos) >= 0) &&
- ((LoPos == RelocLs.end()) || ((CompareOffset(*R, *LoPos) < 0)) ||
- (!MatchedLo && !CompareOffset(*R, *LoPos))))
- LoPos = R;
-
- MatchedLo = NeedsMatchingLo(Asm, *R) &&
- HasMatchingLo(Asm, R, --RelocLs.end());
- }
-
- // If a matching LoPos was found, move HiPos and insert it before LoPos.
- // Make the offsets of HiPos and LoPos match.
- if (LoPos != RelocLs.end()) {
- HiPos->Offset = LoPos->Offset;
- RelocLs.insert(LoPos, *HiPos);
- RelocLs.erase(HiPos);
- }
- }
-
- // Put the sorted list back in reverse order.
- assert(Relocs.size() == RelocLs.size());
- unsigned I = RelocLs.size();
-
- for (RelLsIter R = RelocLs.begin(); R != RelocLs.end(); ++R)
- Relocs[--I] = R->Reloc;
}
MCObjectWriter *llvm::createMipsELFObjectWriter(raw_ostream &OS,
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