//===-- PPCELFObjectWriter.cpp - PPC ELF Writer ---------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "MCTargetDesc/PPCMCTargetDesc.h" #include "MCTargetDesc/PPCFixupKinds.h" #include "llvm/ADT/STLExtras.h" #include "llvm/MC/MCELFObjectWriter.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCValue.h" #include "llvm/Support/ErrorHandling.h" using namespace llvm; namespace { class PPCELFObjectWriter : public MCELFObjectTargetWriter { public: PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI); virtual ~PPCELFObjectWriter(); protected: virtual unsigned getRelocTypeInner(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel) const; virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel, bool IsRelocWithSymbol, int64_t Addend) const; virtual const MCSymbol *undefinedExplicitRelSym(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel) const; virtual void adjustFixupOffset(const MCFixup &Fixup, uint64_t &RelocOffset); virtual void sortRelocs(const MCAssembler &Asm, std::vector &Relocs); }; class PPCELFRelocationEntry : public ELFRelocationEntry { public: PPCELFRelocationEntry(const ELFRelocationEntry &RE); bool operator<(const PPCELFRelocationEntry &RE) const { return (RE.r_offset < r_offset || (RE.r_offset == r_offset && RE.Type > Type)); } }; } PPCELFRelocationEntry::PPCELFRelocationEntry(const ELFRelocationEntry &RE) : ELFRelocationEntry(RE.r_offset, RE.Index, RE.Type, RE.Symbol, RE.r_addend, *RE.Fixup) {} PPCELFObjectWriter::PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI) : MCELFObjectTargetWriter(Is64Bit, OSABI, Is64Bit ? ELF::EM_PPC64 : ELF::EM_PPC, /*HasRelocationAddend*/ true) {} PPCELFObjectWriter::~PPCELFObjectWriter() { } unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel) const { MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ? MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); // determine the type of the relocation unsigned Type; if (IsPCRel) { switch ((unsigned)Fixup.getKind()) { default: llvm_unreachable("Unimplemented"); case PPC::fixup_ppc_br24: Type = ELF::R_PPC_REL24; break; case FK_Data_4: case FK_PCRel_4: Type = ELF::R_PPC_REL32; break; case FK_Data_8: case FK_PCRel_8: Type = ELF::R_PPC64_REL64; break; } } else { switch ((unsigned)Fixup.getKind()) { default: llvm_unreachable("invalid fixup kind!"); case PPC::fixup_ppc_br24: Type = ELF::R_PPC_ADDR24; break; case PPC::fixup_ppc_brcond14: Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_ break; case PPC::fixup_ppc_ha16: switch (Modifier) { default: llvm_unreachable("Unsupported Modifier"); case MCSymbolRefExpr::VK_PPC_TPREL16_HA: Type = ELF::R_PPC_TPREL16_HA; break; case MCSymbolRefExpr::VK_PPC_DTPREL16_HA: Type = ELF::R_PPC64_DTPREL16_HA; break; case MCSymbolRefExpr::VK_None: Type = ELF::R_PPC_ADDR16_HA; break; case MCSymbolRefExpr::VK_PPC_TOC16_HA: Type = ELF::R_PPC64_TOC16_HA; break; case MCSymbolRefExpr::VK_PPC_GOT_TPREL16_HA: Type = ELF::R_PPC64_GOT_TPREL16_HA; break; case MCSymbolRefExpr::VK_PPC_GOT_TLSGD16_HA: Type = ELF::R_PPC64_GOT_TLSGD16_HA; break; case MCSymbolRefExpr::VK_PPC_GOT_TLSLD16_HA: Type = ELF::R_PPC64_GOT_TLSLD16_HA; break; } break; case PPC::fixup_ppc_lo16: switch (Modifier) { default: llvm_unreachable("Unsupported Modifier"); case MCSymbolRefExpr::VK_PPC_TPREL16_LO: Type = ELF::R_PPC_TPREL16_LO; break; case MCSymbolRefExpr::VK_PPC_DTPREL16_LO: Type = ELF::R_PPC64_DTPREL16_LO; break; case MCSymbolRefExpr::VK_None: Type = ELF::R_PPC_ADDR16_LO; break; case MCSymbolRefExpr::VK_PPC_TOC16_LO: Type = ELF::R_PPC64_TOC16_LO; break; case MCSymbolRefExpr::VK_PPC_GOT_TLSGD16_LO: Type = ELF::R_PPC64_GOT_TLSGD16_LO; break; case MCSymbolRefExpr::VK_PPC_GOT_TLSLD16_LO: Type = ELF::R_PPC64_GOT_TLSLD16_LO; break; } break; case PPC::fixup_ppc_lo14: Type = ELF::R_PPC_ADDR14; break; case PPC::fixup_ppc_toc: Type = ELF::R_PPC64_TOC; break; case PPC::fixup_ppc_toc16: switch (Modifier) { default: llvm_unreachable("Unsupported Modifier"); case MCSymbolRefExpr::VK_PPC_TPREL16_LO: Type = ELF::R_PPC64_TPREL16_LO; break; case MCSymbolRefExpr::VK_PPC_DTPREL16_LO: Type = ELF::R_PPC64_DTPREL16_LO; break; case MCSymbolRefExpr::VK_None: Type = ELF::R_PPC64_TOC16; break; case MCSymbolRefExpr::VK_PPC_TOC16_LO: Type = ELF::R_PPC64_TOC16_LO; break; case MCSymbolRefExpr::VK_PPC_GOT_TLSLD16_LO: Type = ELF::R_PPC64_GOT_TLSLD16_LO; break; } break; case PPC::fixup_ppc_toc16_ds: switch (Modifier) { default: llvm_unreachable("Unsupported Modifier"); case MCSymbolRefExpr::VK_PPC_TOC_ENTRY: Type = ELF::R_PPC64_TOC16_DS; break; case MCSymbolRefExpr::VK_PPC_TOC16_LO: Type = ELF::R_PPC64_TOC16_LO_DS; break; case MCSymbolRefExpr::VK_PPC_GOT_TPREL16_LO: Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; break; } break; case PPC::fixup_ppc_tlsreg: Type = ELF::R_PPC64_TLS; break; case PPC::fixup_ppc_nofixup: switch (Modifier) { default: llvm_unreachable("Unsupported Modifier"); case MCSymbolRefExpr::VK_PPC_TLSGD: Type = ELF::R_PPC64_TLSGD; break; case MCSymbolRefExpr::VK_PPC_TLSLD: Type = ELF::R_PPC64_TLSLD; break; } break; case FK_Data_8: switch (Modifier) { default: llvm_unreachable("Unsupported Modifier"); case MCSymbolRefExpr::VK_PPC_TOC: Type = ELF::R_PPC64_TOC; break; case MCSymbolRefExpr::VK_None: Type = ELF::R_PPC64_ADDR64; break; } break; case FK_Data_4: Type = ELF::R_PPC_ADDR32; break; case FK_Data_2: Type = ELF::R_PPC_ADDR16; break; } } return Type; } unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel, bool IsRelocWithSymbol, int64_t Addend) const { return getRelocTypeInner(Target, Fixup, IsPCRel); } const MCSymbol *PPCELFObjectWriter::undefinedExplicitRelSym(const MCValue &Target, const MCFixup &Fixup, bool IsPCRel) const { assert(Target.getSymA() && "SymA cannot be 0"); const MCSymbol &Symbol = Target.getSymA()->getSymbol().AliasedSymbol(); unsigned RelocType = getRelocTypeInner(Target, Fixup, IsPCRel); // The .odp creation emits a relocation against the symbol ".TOC." which // create a R_PPC64_TOC relocation. However the relocation symbol name // in final object creation should be NULL, since the symbol does not // really exist, it is just the reference to TOC base for the current // object file. bool EmitThisSym = RelocType != ELF::R_PPC64_TOC; if (EmitThisSym && !Symbol.isTemporary()) return &Symbol; return NULL; } void PPCELFObjectWriter:: adjustFixupOffset(const MCFixup &Fixup, uint64_t &RelocOffset) { switch ((unsigned)Fixup.getKind()) { case PPC::fixup_ppc_ha16: case PPC::fixup_ppc_lo16: case PPC::fixup_ppc_toc16: case PPC::fixup_ppc_toc16_ds: RelocOffset += 2; break; default: break; } } // The standard sorter only sorts on the r_offset field, but PowerPC can // have multiple relocations at the same offset. Sort secondarily on the // relocation type to avoid nondeterminism. void PPCELFObjectWriter::sortRelocs(const MCAssembler &Asm, std::vector &Relocs) { // Copy to a temporary vector of relocation entries having a different // sort function. std::vector TmpRelocs; for (std::vector::iterator R = Relocs.begin(); R != Relocs.end(); ++R) { TmpRelocs.push_back(PPCELFRelocationEntry(*R)); } // Sort in place by ascending r_offset and descending r_type. array_pod_sort(TmpRelocs.begin(), TmpRelocs.end()); // Copy back to the original vector. unsigned I = 0; for (std::vector::iterator R = TmpRelocs.begin(); R != TmpRelocs.end(); ++R, ++I) { Relocs[I] = ELFRelocationEntry(R->r_offset, R->Index, R->Type, R->Symbol, R->r_addend, *R->Fixup); } } MCObjectWriter *llvm::createPPCELFObjectWriter(raw_ostream &OS, bool Is64Bit, uint8_t OSABI) { MCELFObjectTargetWriter *MOTW = new PPCELFObjectWriter(Is64Bit, OSABI); return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/false); }