diff options
| -rw-r--r-- | lib/MC/MachObjectWriter.cpp | 72 |
1 files changed, 68 insertions, 4 deletions
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp index 167cda7..b746683 100644 --- a/lib/MC/MachObjectWriter.cpp +++ b/lib/MC/MachObjectWriter.cpp @@ -796,6 +796,70 @@ public: Relocations[Fragment->getParent()].push_back(MRE); } + void RecordARMScatteredRelocation(const MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCFragment *Fragment, + const MCFixup &Fixup, MCValue Target, + uint64_t &FixedValue) { + uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset(); + unsigned IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind()); + unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind()); + unsigned Type = macho::RIT_Vanilla; + + // See <reloc.h>. + const MCSymbol *A = &Target.getSymA()->getSymbol(); + MCSymbolData *A_SD = &Asm.getSymbolData(*A); + + if (!A_SD->getFragment()) + report_fatal_error("symbol '" + A->getName() + + "' can not be undefined in a subtraction expression"); + + uint32_t Value = getSymbolAddress(A_SD, Layout); + uint64_t SecAddr = getSectionAddress(A_SD->getFragment()->getParent()); + FixedValue += SecAddr; + uint32_t Value2 = 0; + + if (const MCSymbolRefExpr *B = Target.getSymB()) { + MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol()); + + if (!B_SD->getFragment()) + report_fatal_error("symbol '" + B->getSymbol().getName() + + "' can not be undefined in a subtraction expression"); + + // Select the appropriate difference relocation type. + // + // Note that there is no longer any semantic difference between these two + // relocation types from the linkers point of view, this is done solely + // for pedantic compatibility with 'as'. + Type = A_SD->isExternal() ? (unsigned)macho::RIT_Difference : + (unsigned)macho::RIT_Generic_LocalDifference; + Value2 = getSymbolAddress(B_SD, Layout); + FixedValue -= getSectionAddress(B_SD->getFragment()->getParent()); + } + + // Relocations are written out in reverse order, so the PAIR comes first. + if (Type == macho::RIT_Difference || + Type == macho::RIT_Generic_LocalDifference) { + macho::RelocationEntry MRE; + MRE.Word0 = ((0 << 0) | + (macho::RIT_Pair << 24) | + (Log2Size << 28) | + (IsPCRel << 30) | + macho::RF_Scattered); + MRE.Word1 = Value2; + Relocations[Fragment->getParent()].push_back(MRE); + } + + macho::RelocationEntry MRE; + MRE.Word0 = ((FixupOffset << 0) | + (Type << 24) | + (Log2Size << 28) | + (IsPCRel << 30) | + macho::RF_Scattered); + MRE.Word1 = Value; + Relocations[Fragment->getParent()].push_back(MRE); + } + void RecordTLVPRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout, const MCFragment *Fragment, @@ -889,8 +953,8 @@ public: // a scattered relocation entry. Differences always require scattered // relocations. if (Target.getSymB()) - return RecordScatteredRelocation(Asm, Layout, Fragment, Fixup, - Target, FixedValue); + return RecordARMScatteredRelocation(Asm, Layout, Fragment, Fixup, + Target, FixedValue); // Get the symbol data, if any. MCSymbolData *SD = 0; @@ -906,8 +970,8 @@ public: if (IsPCRel) Offset += 1 << Log2Size; if (Offset && SD && !doesSymbolRequireExternRelocation(SD)) - return RecordScatteredRelocation(Asm, Layout, Fragment, Fixup, - Target, FixedValue); + return RecordARMScatteredRelocation(Asm, Layout, Fragment, Fixup, + Target, FixedValue); // See <reloc.h>. uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset(); |