diff options
Diffstat (limited to 'lib/Target/PowerPC/MCTargetDesc')
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp | 44 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp | 6 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h | 3 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp | 9 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp | 2 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp | 49 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h | 7 | ||||
| -rw-r--r-- | lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp | 389 |
9 files changed, 473 insertions, 37 deletions
diff --git a/lib/Target/PowerPC/MCTargetDesc/CMakeLists.txt b/lib/Target/PowerPC/MCTargetDesc/CMakeLists.txt index 45be471..3efa5ec 100644 --- a/lib/Target/PowerPC/MCTargetDesc/CMakeLists.txt +++ b/lib/Target/PowerPC/MCTargetDesc/CMakeLists.txt @@ -5,6 +5,7 @@ add_llvm_library(LLVMPowerPCDesc PPCMCCodeEmitter.cpp PPCMCExpr.cpp PPCPredicates.cpp + PPCMachObjectWriter.cpp PPCELFObjectWriter.cpp ) diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp index b2a8701..0d42081 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp @@ -16,9 +16,9 @@ #include "llvm/MC/MCObjectWriter.h" #include "llvm/MC/MCSectionMachO.h" #include "llvm/MC/MCValue.h" -#include "llvm/Object/MachOFormat.h" #include "llvm/Support/ELF.h" #include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/MachO.h" #include "llvm/Support/TargetRegistry.h" using namespace llvm; @@ -69,19 +69,6 @@ static unsigned getFixupKindNumBytes(unsigned Kind) { } namespace { -class PPCMachObjectWriter : public MCMachObjectTargetWriter { -public: - PPCMachObjectWriter(bool Is64Bit, uint32_t CPUType, - uint32_t CPUSubtype) - : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype) {} - - void RecordRelocation(MachObjectWriter *Writer, - const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCFragment *Fragment, const MCFixup &Fixup, - MCValue Target, uint64_t &FixedValue) { - llvm_unreachable("Relocation emission for MachO/PPC unimplemented!"); - } -}; class PPCAsmBackend : public MCAsmBackend { const Target &TheTarget; @@ -145,14 +132,17 @@ public: } bool writeNopData(uint64_t Count, MCObjectWriter *OW) const { - // Can't emit NOP with size not multiple of 32-bits - if (Count % 4 != 0) - return false; - uint64_t NumNops = Count / 4; for (uint64_t i = 0; i != NumNops; ++i) OW->Write32(0x60000000); + switch (Count % 4) { + default: break; // No leftover bytes to write + case 1: OW->Write8(0); break; + case 2: OW->Write16(0); break; + case 3: OW->Write16(0); OW->Write8(0); break; + } + return true; } @@ -174,12 +164,11 @@ namespace { MCObjectWriter *createObjectWriter(raw_ostream &OS) const { bool is64 = getPointerSize() == 8; - return createMachObjectWriter(new PPCMachObjectWriter( - /*Is64Bit=*/is64, - (is64 ? object::mach::CTM_PowerPC64 : - object::mach::CTM_PowerPC), - object::mach::CSPPC_ALL), - OS, /*IsLittleEndian=*/false); + return createPPCMachObjectWriter( + OS, + /*Is64Bit=*/is64, + (is64 ? MachO::CPU_TYPE_POWERPC64 : MachO::CPU_TYPE_POWERPC), + MachO::CPU_SUBTYPE_POWERPC_ALL); } virtual bool doesSectionRequireSymbols(const MCSection &Section) const { @@ -206,10 +195,9 @@ namespace { } // end anonymous namespace - - - -MCAsmBackend *llvm::createPPCAsmBackend(const Target &T, StringRef TT, StringRef CPU) { +MCAsmBackend *llvm::createPPCAsmBackend(const Target &T, + const MCRegisterInfo &MRI, + StringRef TT, StringRef CPU) { if (Triple(TT).isOSDarwin()) return new DarwinPPCAsmBackend(T); diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp index 6822507..f3dddce 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp @@ -22,7 +22,6 @@ PPCMCAsmInfoDarwin::PPCMCAsmInfoDarwin(bool is64Bit) { } IsLittleEndian = false; - PCSymbol = "."; CommentString = ";"; ExceptionsType = ExceptionHandling::DwarfCFI; @@ -47,15 +46,14 @@ PPCLinuxMCAsmInfo::PPCLinuxMCAsmInfo(bool is64Bit) { CommentString = "#"; GlobalPrefix = ""; PrivateGlobalPrefix = ".L"; - WeakRefDirective = "\t.weak\t"; - + // Uses '.section' before '.bss' directive UsesELFSectionDirectiveForBSS = true; // Debug Information SupportsDebugInformation = true; - PCSymbol = "."; + DollarIsPC = true; // Set up DWARF directives HasLEB128 = true; // Target asm supports leb128 directives (little-endian) diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h b/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h index 7b4ed9f..1530e77 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h @@ -15,6 +15,7 @@ #define PPCTARGETASMINFO_H #include "llvm/MC/MCAsmInfoDarwin.h" +#include "llvm/MC/MCAsmInfoELF.h" namespace llvm { @@ -24,7 +25,7 @@ namespace llvm { explicit PPCMCAsmInfoDarwin(bool is64Bit); }; - class PPCLinuxMCAsmInfo : public MCAsmInfo { + class PPCLinuxMCAsmInfo : public MCAsmInfoELF { virtual void anchor(); public: explicit PPCLinuxMCAsmInfo(bool is64Bit); diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp index 59ba9c4..346a9be 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp @@ -23,6 +23,7 @@ #include "llvm/MC/MCSubtargetInfo.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetOpcodes.h" using namespace llvm; STATISTIC(MCNumEmitted, "Number of MC instructions emitted"); @@ -76,11 +77,17 @@ public: SmallVectorImpl<MCFixup> &Fixups) const; void EncodeInstruction(const MCInst &MI, raw_ostream &OS, SmallVectorImpl<MCFixup> &Fixups) const { + // For fast-isel, a float COPY_TO_REGCLASS can survive this long. + // It's just a nop to keep the register classes happy, so don't + // generate anything. + unsigned Opcode = MI.getOpcode(); + if (Opcode == TargetOpcode::COPY_TO_REGCLASS) + return; + uint64_t Bits = getBinaryCodeForInstr(MI, Fixups); // BL8_NOP etc. all have a size of 8 because of the following 'nop'. unsigned Size = 4; // FIXME: Have Desc.getSize() return the correct value! - unsigned Opcode = MI.getOpcode(); if (Opcode == PPC::BL8_NOP || Opcode == PPC::BLA8_NOP || Opcode == PPC::BL8_NOP_TLS) Size = 8; diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp index 9529267..d7e8402 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp @@ -54,7 +54,7 @@ PPCMCExpr::EvaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout) const { MCValue Value; - if (!getSubExpr()->EvaluateAsRelocatable(Value, *Layout)) + if (!Layout || !getSubExpr()->EvaluateAsRelocatable(Value, *Layout)) return false; if (Value.isAbsolute()) { diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp index 5f7a39a..f18d095 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp @@ -14,13 +14,16 @@ #include "PPCMCTargetDesc.h" #include "InstPrinter/PPCInstPrinter.h" #include "PPCMCAsmInfo.h" +#include "PPCTargetStreamer.h" #include "llvm/MC/MCCodeGenInfo.h" #include "llvm/MC/MCInstrInfo.h" #include "llvm/MC/MCRegisterInfo.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MCSubtargetInfo.h" +#include "llvm/MC/MCSymbol.h" #include "llvm/MC/MachineLocation.h" #include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/FormattedStream.h" #include "llvm/Support/TargetRegistry.h" #define GET_INSTRINFO_MC_DESC @@ -34,6 +37,9 @@ using namespace llvm; +// Pin the vtable to this file. +PPCTargetStreamer::~PPCTargetStreamer() {} + static MCInstrInfo *createPPCMCInstrInfo() { MCInstrInfo *X = new MCInstrInfo(); InitPPCMCInstrInfo(X); @@ -101,6 +107,29 @@ static MCCodeGenInfo *createPPCMCCodeGenInfo(StringRef TT, Reloc::Model RM, return X; } +namespace { +class PPCTargetAsmStreamer : public PPCTargetStreamer { + formatted_raw_ostream &OS; + +public: + PPCTargetAsmStreamer(formatted_raw_ostream &OS) : OS(OS) {} + virtual void emitTCEntry(const MCSymbol &S) { + OS << "\t.tc "; + OS << S.getName(); + OS << "[TC],"; + OS << S.getName(); + OS << '\n'; + } +}; + +class PPCTargetELFStreamer : public PPCTargetStreamer { + virtual void emitTCEntry(const MCSymbol &S) { + // Creates a R_PPC64_TOC relocation + Streamer->EmitSymbolValue(&S, 8); + } +}; +} + // This is duplicated code. Refactor this. static MCStreamer *createMCStreamer(const Target &T, StringRef TT, MCContext &Ctx, MCAsmBackend &MAB, @@ -111,7 +140,20 @@ static MCStreamer *createMCStreamer(const Target &T, StringRef TT, if (Triple(TT).isOSDarwin()) return createMachOStreamer(Ctx, MAB, OS, Emitter, RelaxAll); - return createELFStreamer(Ctx, MAB, OS, Emitter, RelaxAll, NoExecStack); + PPCTargetStreamer *S = new PPCTargetELFStreamer(); + return createELFStreamer(Ctx, S, MAB, OS, Emitter, RelaxAll, NoExecStack); +} + +static MCStreamer * +createMCAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, + bool isVerboseAsm, bool useLoc, bool useCFI, + bool useDwarfDirectory, MCInstPrinter *InstPrint, + MCCodeEmitter *CE, MCAsmBackend *TAB, bool ShowInst) { + PPCTargetStreamer *S = new PPCTargetAsmStreamer(OS); + + return llvm::createAsmStreamer(Ctx, S, OS, isVerboseAsm, useLoc, useCFI, + useDwarfDirectory, InstPrint, CE, TAB, + ShowInst); } static MCInstPrinter *createPPCMCInstPrinter(const Target &T, @@ -171,6 +213,11 @@ extern "C" void LLVMInitializePowerPCTargetMC() { TargetRegistry::RegisterMCObjectStreamer(ThePPC64Target, createMCStreamer); TargetRegistry::RegisterMCObjectStreamer(ThePPC64LETarget, createMCStreamer); + // Register the asm streamer. + TargetRegistry::RegisterAsmStreamer(ThePPC32Target, createMCAsmStreamer); + TargetRegistry::RegisterAsmStreamer(ThePPC64Target, createMCAsmStreamer); + TargetRegistry::RegisterAsmStreamer(ThePPC64LETarget, createMCAsmStreamer); + // Register the MCInstPrinter. TargetRegistry::RegisterMCInstPrinter(ThePPC32Target, createPPCMCInstPrinter); TargetRegistry::RegisterMCInstPrinter(ThePPC64Target, createPPCMCInstPrinter); diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h b/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h index 9f29132..0b0ca24 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h @@ -40,12 +40,17 @@ MCCodeEmitter *createPPCMCCodeEmitter(const MCInstrInfo &MCII, const MCSubtargetInfo &STI, MCContext &Ctx); -MCAsmBackend *createPPCAsmBackend(const Target &T, StringRef TT, StringRef CPU); +MCAsmBackend *createPPCAsmBackend(const Target &T, const MCRegisterInfo &MRI, + StringRef TT, StringRef CPU); /// createPPCELFObjectWriter - Construct an PPC ELF object writer. MCObjectWriter *createPPCELFObjectWriter(raw_ostream &OS, bool Is64Bit, uint8_t OSABI); +/// createPPCELFObjectWriter - Construct a PPC Mach-O object writer. +MCObjectWriter *createPPCMachObjectWriter(raw_ostream &OS, bool Is64Bit, + uint32_t CPUType, + uint32_t CPUSubtype); } // End llvm namespace // Generated files will use "namespace PPC". To avoid symbol clash, diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp new file mode 100644 index 0000000..bbafe2e --- /dev/null +++ b/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp @@ -0,0 +1,389 @@ +//===-- PPCMachObjectWriter.cpp - PPC Mach-O 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/Twine.h" +#include "llvm/MC/MCAsmLayout.h" +#include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCMachObjectWriter.h" +#include "llvm/MC/MCSectionMachO.h" +#include "llvm/MC/MCValue.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/Format.h" +#include "llvm/Support/MachO.h" + +using namespace llvm; + +namespace { +class PPCMachObjectWriter : public MCMachObjectTargetWriter { + bool RecordScatteredRelocation(MachObjectWriter *Writer, + const MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCFragment *Fragment, + const MCFixup &Fixup, MCValue Target, + unsigned Log2Size, uint64_t &FixedValue); + + void RecordPPCRelocation(MachObjectWriter *Writer, const MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCFragment *Fragment, const MCFixup &Fixup, + MCValue Target, uint64_t &FixedValue); + +public: + PPCMachObjectWriter(bool Is64Bit, uint32_t CPUType, uint32_t CPUSubtype) + : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype, + /*UseAggressiveSymbolFolding=*/Is64Bit) {} + + void RecordRelocation(MachObjectWriter *Writer, const MCAssembler &Asm, + const MCAsmLayout &Layout, const MCFragment *Fragment, + const MCFixup &Fixup, MCValue Target, + uint64_t &FixedValue) { + if (Writer->is64Bit()) { + report_fatal_error("Relocation emission for MachO/PPC64 unimplemented."); + } else + RecordPPCRelocation(Writer, Asm, Layout, Fragment, Fixup, Target, + FixedValue); + } +}; +} + +/// computes the log2 of the size of the relocation, +/// used for relocation_info::r_length. +static unsigned getFixupKindLog2Size(unsigned Kind) { + switch (Kind) { + default: + report_fatal_error("log2size(FixupKind): Unhandled fixup kind!"); + case FK_PCRel_1: + case FK_Data_1: + return 0; + case FK_PCRel_2: + case FK_Data_2: + return 1; + case FK_PCRel_4: + case PPC::fixup_ppc_brcond14: + case PPC::fixup_ppc_half16: + case PPC::fixup_ppc_br24: + case FK_Data_4: + return 2; + case FK_PCRel_8: + case FK_Data_8: + return 3; + } + return 0; +} + +/// Translates generic PPC fixup kind to Mach-O/PPC relocation type enum. +/// Outline based on PPCELFObjectWriter::getRelocTypeInner(). +static unsigned getRelocType(const MCValue &Target, + const MCFixupKind FixupKind, // from + // Fixup.getKind() + const bool IsPCRel) { + const MCSymbolRefExpr::VariantKind Modifier = + Target.isAbsolute() ? MCSymbolRefExpr::VK_None + : Target.getSymA()->getKind(); + // determine the type of the relocation + unsigned Type = MachO::GENERIC_RELOC_VANILLA; + if (IsPCRel) { // relative to PC + switch ((unsigned)FixupKind) { + default: + report_fatal_error("Unimplemented fixup kind (relative)"); + case PPC::fixup_ppc_br24: + Type = MachO::PPC_RELOC_BR24; // R_PPC_REL24 + break; + case PPC::fixup_ppc_brcond14: + Type = MachO::PPC_RELOC_BR14; + break; + case PPC::fixup_ppc_half16: + switch (Modifier) { + default: + llvm_unreachable("Unsupported modifier for half16 fixup"); + case MCSymbolRefExpr::VK_PPC_HA: + Type = MachO::PPC_RELOC_HA16; + break; + case MCSymbolRefExpr::VK_PPC_LO: + Type = MachO::PPC_RELOC_LO16; + break; + case MCSymbolRefExpr::VK_PPC_HI: + Type = MachO::PPC_RELOC_HI16; + break; + } + break; + } + } else { + switch ((unsigned)FixupKind) { + default: + report_fatal_error("Unimplemented fixup kind (absolute)!"); + case PPC::fixup_ppc_half16: + switch (Modifier) { + default: + llvm_unreachable("Unsupported modifier for half16 fixup"); + case MCSymbolRefExpr::VK_PPC_HA: + Type = MachO::PPC_RELOC_HA16_SECTDIFF; + break; + case MCSymbolRefExpr::VK_PPC_LO: + Type = MachO::PPC_RELOC_LO16_SECTDIFF; + break; + case MCSymbolRefExpr::VK_PPC_HI: + Type = MachO::PPC_RELOC_HI16_SECTDIFF; + break; + } + break; + case FK_Data_4: + break; + case FK_Data_2: + break; + } + } + return Type; +} + +static void makeRelocationInfo(MachO::any_relocation_info &MRE, + const uint32_t FixupOffset, const uint32_t Index, + const unsigned IsPCRel, const unsigned Log2Size, + const unsigned IsExtern, const unsigned Type) { + MRE.r_word0 = FixupOffset; + // The bitfield offsets that work (as determined by trial-and-error) + // are different than what is documented in the mach-o manuals. + // This appears to be an endianness issue; reversing the order of the + // documented bitfields in <llvm/Support/MachO.h> fixes this (but + // breaks x86/ARM assembly). + MRE.r_word1 = ((Index << 8) | // was << 0 + (IsPCRel << 7) | // was << 24 + (Log2Size << 5) | // was << 25 + (IsExtern << 4) | // was << 27 + (Type << 0)); // was << 28 +} + +static void +makeScatteredRelocationInfo(MachO::any_relocation_info &MRE, + const uint32_t Addr, const unsigned Type, + const unsigned Log2Size, const unsigned IsPCRel, + const uint32_t Value2) { + // For notes on bitfield positions and endianness, see: + // https://developer.apple.com/library/mac/documentation/developertools/conceptual/MachORuntime/Reference/reference.html#//apple_ref/doc/uid/20001298-scattered_relocation_entry + MRE.r_word0 = ((Addr << 0) | (Type << 24) | (Log2Size << 28) | + (IsPCRel << 30) | MachO::R_SCATTERED); + MRE.r_word1 = Value2; +} + +/// Compute fixup offset (address). +static uint32_t getFixupOffset(const MCAsmLayout &Layout, + const MCFragment *Fragment, + const MCFixup &Fixup) { + uint32_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); + // On Mach-O, ppc_fixup_half16 relocations must refer to the + // start of the instruction, not the second halfword, as ELF does + if (unsigned(Fixup.getKind()) == PPC::fixup_ppc_half16) + FixupOffset &= ~uint32_t(3); + return FixupOffset; +} + +/// \return false if falling back to using non-scattered relocation, +/// otherwise true for normal scattered relocation. +/// based on X86MachObjectWriter::RecordScatteredRelocation +/// and ARMMachObjectWriter::RecordScatteredRelocation +bool PPCMachObjectWriter::RecordScatteredRelocation( + MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target, + unsigned Log2Size, uint64_t &FixedValue) { + // caller already computes these, can we just pass and reuse? + const uint32_t FixupOffset = getFixupOffset(Layout, Fragment, Fixup); + const MCFixupKind FK = Fixup.getKind(); + const unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, FK); + const unsigned Type = getRelocType(Target, FK, IsPCRel); + + // Is this a local or SECTDIFF relocation entry? + // SECTDIFF relocation entries have symbol subtractions, + // and require two entries, the first for the add-symbol value, + // the second for the subtract-symbol value. + + // 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 = Writer->getSymbolAddress(A_SD, Layout); + uint64_t SecAddr = + Writer->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"); + + // FIXME: is Type correct? see include/llvm/Support/MachO.h + Value2 = Writer->getSymbolAddress(B_SD, Layout); + FixedValue -= Writer->getSectionAddress(B_SD->getFragment()->getParent()); + } + // FIXME: does FixedValue get used?? + + // Relocations are written out in reverse order, so the PAIR comes first. + if (Type == MachO::PPC_RELOC_SECTDIFF || + Type == MachO::PPC_RELOC_HI16_SECTDIFF || + Type == MachO::PPC_RELOC_LO16_SECTDIFF || + Type == MachO::PPC_RELOC_HA16_SECTDIFF || + Type == MachO::PPC_RELOC_LO14_SECTDIFF || + Type == MachO::PPC_RELOC_LOCAL_SECTDIFF) { + // X86 had this piece, but ARM does not + // If the offset is too large to fit in a scattered relocation, + // we're hosed. It's an unfortunate limitation of the MachO format. + if (FixupOffset > 0xffffff) { + char Buffer[32]; + format("0x%x", FixupOffset).print(Buffer, sizeof(Buffer)); + Asm.getContext().FatalError(Fixup.getLoc(), + Twine("Section too large, can't encode " + "r_address (") + + Buffer + ") into 24 bits of scattered " + "relocation entry."); + llvm_unreachable("fatal error returned?!"); + } + + // Is this supposed to follow MCTarget/PPCAsmBackend.cpp:adjustFixupValue()? + // see PPCMCExpr::EvaluateAsRelocatableImpl() + uint32_t other_half = 0; + switch (Type) { + case MachO::PPC_RELOC_LO16_SECTDIFF: + other_half = (FixedValue >> 16) & 0xffff; + // applyFixupOffset longer extracts the high part because it now assumes + // this was already done. + // It looks like this is not true for the FixedValue needed with Mach-O + // relocs. + // So we need to adjust FixedValue again here. + FixedValue &= 0xffff; + break; + case MachO::PPC_RELOC_HA16_SECTDIFF: + other_half = FixedValue & 0xffff; + FixedValue = + ((FixedValue >> 16) + ((FixedValue & 0x8000) ? 1 : 0)) & 0xffff; + break; + case MachO::PPC_RELOC_HI16_SECTDIFF: + other_half = FixedValue & 0xffff; + FixedValue = (FixedValue >> 16) & 0xffff; + break; + default: + llvm_unreachable("Invalid PPC scattered relocation type."); + break; + } + + MachO::any_relocation_info MRE; + makeScatteredRelocationInfo(MRE, other_half, MachO::GENERIC_RELOC_PAIR, + Log2Size, IsPCRel, Value2); + Writer->addRelocation(Fragment->getParent(), MRE); + } else { + // If the offset is more than 24-bits, it won't fit in a scattered + // relocation offset field, so we fall back to using a non-scattered + // relocation. This is a bit risky, as if the offset reaches out of + // the block and the linker is doing scattered loading on this + // symbol, things can go badly. + // + // Required for 'as' compatibility. + if (FixupOffset > 0xffffff) + return false; + } + MachO::any_relocation_info MRE; + makeScatteredRelocationInfo(MRE, FixupOffset, Type, Log2Size, IsPCRel, Value); + Writer->addRelocation(Fragment->getParent(), MRE); + return true; +} + +// see PPCELFObjectWriter for a general outline of cases +void PPCMachObjectWriter::RecordPPCRelocation( + MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target, + uint64_t &FixedValue) { + const MCFixupKind FK = Fixup.getKind(); // unsigned + const unsigned Log2Size = getFixupKindLog2Size(FK); + const bool IsPCRel = Writer->isFixupKindPCRel(Asm, FK); + const unsigned RelocType = getRelocType(Target, FK, IsPCRel); + + // If this is a difference or a defined symbol plus an offset, then we need a + // scattered relocation entry. Differences always require scattered + // relocations. + if (Target.getSymB() && + // Q: are branch targets ever scattered? + RelocType != MachO::PPC_RELOC_BR24 && + RelocType != MachO::PPC_RELOC_BR14) { + RecordScatteredRelocation(Writer, Asm, Layout, Fragment, Fixup, Target, + Log2Size, FixedValue); + return; + } + + // this doesn't seem right for RIT_PPC_BR24 + // Get the symbol data, if any. + MCSymbolData *SD = 0; + if (Target.getSymA()) + SD = &Asm.getSymbolData(Target.getSymA()->getSymbol()); + + // See <reloc.h>. + const uint32_t FixupOffset = getFixupOffset(Layout, Fragment, Fixup); + unsigned Index = 0; + unsigned IsExtern = 0; + unsigned Type = RelocType; + + if (Target.isAbsolute()) { // constant + // SymbolNum of 0 indicates the absolute section. + // + // FIXME: Currently, these are never generated (see code below). I cannot + // find a case where they are actually emitted. + report_fatal_error("FIXME: relocations to absolute targets " + "not yet implemented"); + // the above line stolen from ARM, not sure + } else { + // Resolve constant variables. + if (SD->getSymbol().isVariable()) { + int64_t Res; + if (SD->getSymbol().getVariableValue()->EvaluateAsAbsolute( + Res, Layout, Writer->getSectionAddressMap())) { + FixedValue = Res; + return; + } + } + + // Check whether we need an external or internal relocation. + if (Writer->doesSymbolRequireExternRelocation(SD)) { + IsExtern = 1; + Index = SD->getIndex(); + // For external relocations, make sure to offset the fixup value to + // compensate for the addend of the symbol address, if it was + // undefined. This occurs with weak definitions, for example. + if (!SD->Symbol->isUndefined()) + FixedValue -= Layout.getSymbolOffset(SD); + } else { + // The index is the section ordinal (1-based). + const MCSectionData &SymSD = + Asm.getSectionData(SD->getSymbol().getSection()); + Index = SymSD.getOrdinal() + 1; + FixedValue += Writer->getSectionAddress(&SymSD); + } + if (IsPCRel) + FixedValue -= Writer->getSectionAddress(Fragment->getParent()); + } + + // struct relocation_info (8 bytes) + MachO::any_relocation_info MRE; + makeRelocationInfo(MRE, FixupOffset, Index, IsPCRel, Log2Size, IsExtern, + Type); + Writer->addRelocation(Fragment->getParent(), MRE); +} + +MCObjectWriter *llvm::createPPCMachObjectWriter(raw_ostream &OS, bool Is64Bit, + uint32_t CPUType, + uint32_t CPUSubtype) { + return createMachObjectWriter( + new PPCMachObjectWriter(Is64Bit, CPUType, CPUSubtype), OS, + /*IsLittleEndian=*/false); +} |