X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCMachOStreamer.cpp;h=a10a63ee6a42286fc00ec4c0bdf462c81662d624;hb=345ed9806a0ab5d680da1ff78fe3df7ebbc6107d;hp=143793cde1022cfb3edb2b8059ee027f56dfcf2f;hpb=718fb59801320b8cb22363d115b5fc5ec40dc1f5;p=oota-llvm.git diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp index 143793cde10..a10a63ee6a4 100644 --- a/lib/MC/MCMachOStreamer.cpp +++ b/lib/MC/MCMachOStreamer.cpp @@ -14,105 +14,35 @@ #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCInst.h" +#include "llvm/MC/MCObjectStreamer.h" #include "llvm/MC/MCSection.h" #include "llvm/MC/MCSymbol.h" -#include "llvm/MC/MCValue.h" +#include "llvm/MC/MCMachOSymbolFlags.h" +#include "llvm/MC/MCSectionMachO.h" +#include "llvm/MC/MCDwarf.h" +#include "llvm/Support/Dwarf.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetAsmBackend.h" + using namespace llvm; namespace { -class MCMachOStreamer : public MCStreamer { - /// SymbolFlags - We store the value for the 'desc' symbol field in the lowest - /// 16 bits of the implementation defined flags. - enum SymbolFlags { // See . - SF_DescFlagsMask = 0xFFFF, - - // Reference type flags. - SF_ReferenceTypeMask = 0x0007, - SF_ReferenceTypeUndefinedNonLazy = 0x0000, - SF_ReferenceTypeUndefinedLazy = 0x0001, - SF_ReferenceTypeDefined = 0x0002, - SF_ReferenceTypePrivateDefined = 0x0003, - SF_ReferenceTypePrivateUndefinedNonLazy = 0x0004, - SF_ReferenceTypePrivateUndefinedLazy = 0x0005, - - // Other 'desc' flags. - SF_NoDeadStrip = 0x0020, - SF_WeakReference = 0x0040, - SF_WeakDefinition = 0x0080 - }; - -private: - MCAssembler Assembler; - MCCodeEmitter *Emitter; - MCSectionData *CurSectionData; - DenseMap SectionMap; - DenseMap SymbolMap; - +class MCMachOStreamer : public MCObjectStreamer { private: - MCFragment *getCurrentFragment() const { - assert(CurSectionData && "No current section!"); - - if (!CurSectionData->empty()) - return &CurSectionData->getFragmentList().back(); - - return 0; - } - - MCSectionData &getSectionData(const MCSection &Section) { - MCSectionData *&Entry = SectionMap[&Section]; - - if (!Entry) - Entry = new MCSectionData(Section, &Assembler); - - return *Entry; - } - - MCSymbolData &getSymbolData(const MCSymbol &Symbol) { - MCSymbolData *&Entry = SymbolMap[&Symbol]; - - if (!Entry) - Entry = new MCSymbolData(Symbol, 0, 0, &Assembler); - - return *Entry; - } + void EmitInstToFragment(const MCInst &Inst); + void EmitInstToData(const MCInst &Inst); public: - MCMachOStreamer(MCContext &Context, raw_ostream &_OS, MCCodeEmitter *_Emitter) - : MCStreamer(Context), Assembler(Context, _OS), Emitter(_Emitter), - CurSectionData(0) {} - ~MCMachOStreamer() {} - - const MCExpr *AddValueSymbols(const MCExpr *Value) { - switch (Value->getKind()) { - case MCExpr::Constant: - break; - - case MCExpr::Binary: { - const MCBinaryExpr *BE = cast(Value); - AddValueSymbols(BE->getLHS()); - AddValueSymbols(BE->getRHS()); - break; - } - - case MCExpr::SymbolRef: - getSymbolData(cast(Value)->getSymbol()); - break; - - case MCExpr::Unary: - AddValueSymbols(cast(Value)->getSubExpr()); - break; - } - - return Value; - } + MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB, + raw_ostream &OS, MCCodeEmitter *Emitter) + : MCObjectStreamer(Context, TAB, OS, Emitter, true) {} /// @name MCStreamer Interface /// @{ - virtual void SwitchSection(const MCSection *Section); + virtual void InitSections(); virtual void EmitLabel(MCSymbol *Symbol); virtual void EmitAssemblerFlag(MCAssemblerFlag Flag); virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value); @@ -120,6 +50,18 @@ public: virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue); virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, unsigned ByteAlignment); + virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) { + assert(0 && "macho doesn't support this directive"); + } + virtual void EmitCOFFSymbolStorageClass(int StorageClass) { + assert(0 && "macho doesn't support this directive"); + } + virtual void EmitCOFFSymbolType(int Type) { + assert(0 && "macho doesn't support this directive"); + } + virtual void EndCOFFSymbolDef() { + assert(0 && "macho doesn't support this directive"); + } virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) { assert(0 && "macho doesn't support this directive"); } @@ -128,6 +70,8 @@ public: } virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0, unsigned Size = 0, unsigned ByteAlignment = 0); + virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, + uint64_t Size, unsigned ByteAlignment = 0); virtual void EmitBytes(StringRef Data, unsigned AddrSpace); virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace); virtual void EmitGPRel32Value(const MCExpr *Value) { @@ -136,17 +80,26 @@ public: virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, unsigned ValueSize = 1, unsigned MaxBytesToEmit = 0); + virtual void EmitCodeAlignment(unsigned ByteAlignment, + unsigned MaxBytesToEmit = 0); virtual void EmitValueToOffset(const MCExpr *Offset, unsigned char Value = 0); - + virtual void EmitFileDirective(StringRef Filename) { - errs() << "FIXME: MCMachoStreamer:EmitFileDirective not implemented\n"; + // FIXME: Just ignore the .file; it isn't important enough to fail the + // entire assembly. + + //report_fatal_error("unsupported directive: '.file'"); } virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) { - errs() << "FIXME: MCMachoStreamer:EmitDwarfFileDirective not implemented\n"; + // FIXME: Just ignore the .file; it isn't important enough to fail the + // entire assembly. + + //report_fatal_error("unsupported directive: '.file'"); } - + virtual void EmitInstruction(const MCInst &Inst); + virtual void Finish(); /// @} @@ -154,53 +107,64 @@ public: } // end anonymous namespace. -void MCMachOStreamer::SwitchSection(const MCSection *Section) { - assert(Section && "Cannot switch to a null section!"); - - // If already in this section, then this is a noop. - if (Section == CurSection) return; +void MCMachOStreamer::InitSections() { + SwitchSection(getContext().getMachOSection("__TEXT", "__text", + MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, + 0, SectionKind::getText())); - CurSection = Section; - CurSectionData = &getSectionData(*Section); } void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) { + // TODO: This is almost exactly the same as WinCOFFStreamer. Consider merging + // into MCObjectStreamer. assert(Symbol->isUndefined() && "Cannot define a symbol twice!"); + assert(!Symbol->isVariable() && "Cannot emit a variable symbol!"); + assert(CurSection && "Cannot emit before setting section!"); + + Symbol->setSection(*CurSection); + + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); - // FIXME: We should also use offsets into Fill fragments. - MCDataFragment *F = dyn_cast_or_null(getCurrentFragment()); - if (!F) - F = new MCDataFragment(CurSectionData); + // We have to create a new fragment if this is an atom defining symbol, + // fragments cannot span atoms. + if (getAssembler().isSymbolLinkerVisible(SD.getSymbol())) + new MCDataFragment(getCurrentSectionData()); - MCSymbolData &SD = getSymbolData(*Symbol); + // FIXME: This is wasteful, we don't necessarily need to create a data + // fragment. Instead, we should mark the symbol as pointing into the data + // fragment if it exists, otherwise we should just queue the label and set its + // fragment pointer when we emit the next fragment. + MCDataFragment *F = getOrCreateDataFragment(); assert(!SD.getFragment() && "Unexpected fragment on symbol data!"); SD.setFragment(F); SD.setOffset(F->getContents().size()); - // This causes the reference type and weak reference flags to be cleared. - SD.setFlags(SD.getFlags() & ~(SF_WeakReference | SF_ReferenceTypeMask)); - - Symbol->setSection(*CurSection); + // This causes the reference type flag to be cleared. Darwin 'as' was "trying" + // to clear the weak reference and weak definition bits too, but the + // implementation was buggy. For now we just try to match 'as', for + // diffability. + // + // FIXME: Cleanup this code, these bits should be emitted based on semantic + // properties, not on the order of definition, etc. + SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask); } void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) { switch (Flag) { case MCAF_SubsectionsViaSymbols: - Assembler.setSubsectionsViaSymbols(true); + getAssembler().setSubsectionsViaSymbols(true); return; + default: + llvm_unreachable("invalid assembler flag!"); } - - assert(0 && "invalid assembler flag!"); } void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) { - // Only absolute symbols can be redefined. - assert((Symbol->isUndefined() || Symbol->isAbsolute()) && - "Cannot define a symbol twice!"); - + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. // FIXME: Lift context changes into super class. - // FIXME: Set associated section. - Symbol->setValue(Value); + getAssembler().getOrCreateSymbolData(*Symbol); + Symbol->setVariableValue(AddValueSymbols(Value)); } void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol, @@ -212,15 +176,15 @@ void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol, // important for matching the string table that 'as' generates. IndirectSymbolData ISD; ISD.Symbol = Symbol; - ISD.SectionData = CurSectionData; - Assembler.getIndirectSymbols().push_back(ISD); + ISD.SectionData = getCurrentSectionData(); + getAssembler().getIndirectSymbols().push_back(ISD); return; } // Adding a symbol attribute always introduces the symbol, note that an - // important side effect of calling getSymbolData here is to register the - // symbol with the assembler. - MCSymbolData &SD = getSymbolData(*Symbol); + // important side effect of calling getOrCreateSymbolData here is to register + // the symbol with the assembler. + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); // The implementation of symbol attributes is designed to match 'as', but it // leaves much to desired. It doesn't really make sense to arbitrarily add and @@ -247,6 +211,13 @@ void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol, case MCSA_Global: SD.setExternal(true); + // This effectively clears the undefined lazy bit, in Darwin 'as', although + // it isn't very consistent because it implements this as part of symbol + // lookup. + // + // FIXME: Cleanup this code, these bits should be emitted based on semantic + // properties, not on the order of definition, etc. + SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeUndefinedLazy); break; case MCSA_LazyReference: @@ -279,14 +250,19 @@ void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol, // it has to be in a coalesced section, but this isn't enforced. SD.setFlags(SD.getFlags() | SF_WeakDefinition); break; + + case MCSA_WeakDefAutoPrivate: + SD.setFlags(SD.getFlags() | SF_WeakDefinition | SF_WeakReference); + break; } } void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) { // Encode the 'desc' value into the lowest implementation defined bits. - assert(DescValue == (DescValue & SF_DescFlagsMask) && + assert(DescValue == (DescValue & SF_DescFlagsMask) && "Invalid .desc value!"); - getSymbolData(*Symbol).setFlags(DescValue & SF_DescFlagsMask); + getAssembler().getOrCreateSymbolData(*Symbol).setFlags( + DescValue & SF_DescFlagsMask); } void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, @@ -294,14 +270,14 @@ void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, // FIXME: Darwin 'as' does appear to allow redef of a .comm by itself. assert(Symbol->isUndefined() && "Cannot define a symbol twice!"); - MCSymbolData &SD = getSymbolData(*Symbol); + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); SD.setExternal(true); SD.setCommon(Size, ByteAlignment); } void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol, unsigned Size, unsigned ByteAlignment) { - MCSectionData &SectData = getSectionData(*Section); + MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section); // The symbol may not be present, which only creates the section. if (!Symbol) @@ -311,9 +287,13 @@ void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol, assert(Symbol->isUndefined() && "Cannot define a symbol twice!"); - MCSymbolData &SD = getSymbolData(*Symbol); + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); + + // Emit an align fragment if necessary. + if (ByteAlignment != 1) + new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectData); - MCFragment *F = new MCZeroFillFragment(Size, ByteAlignment, &SectData); + MCFragment *F = new MCFillFragment(0, 0, Size, &SectData); SD.setFragment(F); Symbol->setSection(*Section); @@ -323,59 +303,189 @@ void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol, SectData.setAlignment(ByteAlignment); } +// This should always be called with the thread local bss section. Like the +// .zerofill directive this doesn't actually switch sections on us. +void MCMachOStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, + uint64_t Size, unsigned ByteAlignment) { + EmitZerofill(Section, Symbol, Size, ByteAlignment); + return; +} + void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) { - MCDataFragment *DF = dyn_cast_or_null(getCurrentFragment()); - if (!DF) - DF = new MCDataFragment(CurSectionData); - DF->getContents().append(Data.begin(), Data.end()); + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. + getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end()); } void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace) { - new MCFillFragment(*AddValueSymbols(Value), Size, 1, CurSectionData); + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. + MCDataFragment *DF = getOrCreateDataFragment(); + + // Avoid fixups when possible. + int64_t AbsValue; + if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) { + // FIXME: Endianness assumption. + for (unsigned i = 0; i != Size; ++i) + DF->getContents().push_back(uint8_t(AbsValue >> (i * 8))); + } else { + DF->addFixup(MCFixup::Create(DF->getContents().size(), + AddValueSymbols(Value), + MCFixup::getKindForSize(Size))); + DF->getContents().resize(DF->getContents().size() + Size, 0); + } } void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value, unsigned ValueSize, unsigned MaxBytesToEmit) { + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. if (MaxBytesToEmit == 0) MaxBytesToEmit = ByteAlignment; new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit, - CurSectionData); + getCurrentSectionData()); + + // Update the maximum alignment on the current section if necessary. + if (ByteAlignment > getCurrentSectionData()->getAlignment()) + getCurrentSectionData()->setAlignment(ByteAlignment); +} + +void MCMachOStreamer::EmitCodeAlignment(unsigned ByteAlignment, + unsigned MaxBytesToEmit) { + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. + if (MaxBytesToEmit == 0) + MaxBytesToEmit = ByteAlignment; + MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit, + getCurrentSectionData()); + F->setEmitNops(true); // Update the maximum alignment on the current section if necessary. - if (ByteAlignment > CurSectionData->getAlignment()) - CurSectionData->setAlignment(ByteAlignment); + if (ByteAlignment > getCurrentSectionData()->getAlignment()) + getCurrentSectionData()->setAlignment(ByteAlignment); } void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset, unsigned char Value) { - new MCOrgFragment(*Offset, Value, CurSectionData); + new MCOrgFragment(*Offset, Value, getCurrentSectionData()); +} + +void MCMachOStreamer::EmitInstToFragment(const MCInst &Inst) { + MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData()); + + // Add the fixups and data. + // + // FIXME: Revisit this design decision when relaxation is done, we may be + // able to get away with not storing any extra data in the MCInst. + SmallVector Fixups; + SmallString<256> Code; + raw_svector_ostream VecOS(Code); + getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups); + VecOS.flush(); + + IF->getCode() = Code; + IF->getFixups() = Fixups; +} + +void MCMachOStreamer::EmitInstToData(const MCInst &Inst) { + MCDataFragment *DF = getOrCreateDataFragment(); + + SmallVector Fixups; + SmallString<256> Code; + raw_svector_ostream VecOS(Code); + getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups); + VecOS.flush(); + + // Add the fixups and data. + for (unsigned i = 0, e = Fixups.size(); i != e; ++i) { + Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size()); + DF->addFixup(Fixups[i]); + } + DF->getContents().append(Code.begin(), Code.end()); } void MCMachOStreamer::EmitInstruction(const MCInst &Inst) { // Scan for values. - for (unsigned i = 0; i != Inst.getNumOperands(); ++i) + for (unsigned i = Inst.getNumOperands(); i--; ) if (Inst.getOperand(i).isExpr()) AddValueSymbols(Inst.getOperand(i).getExpr()); - if (!Emitter) - llvm_unreachable("no code emitter available!"); + getCurrentSectionData()->setHasInstructions(true); - // FIXME: Emitting an instruction should cause S_ATTR_SOME_INSTRUCTIONS to - // be set for the current section. - // FIXME: Relocations! - SmallString<256> Code; - raw_svector_ostream VecOS(Code); - Emitter->EncodeInstruction(Inst, VecOS); - EmitBytes(VecOS.str(), 0); + // Now that a machine instruction has been assembled into this section, make + // a line entry for any .loc directive that has been seen. + MCLineEntry::Make(this, getCurrentSection()); + + // If this instruction doesn't need relaxation, just emit it as data. + if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) { + EmitInstToData(Inst); + return; + } + + // Otherwise, if we are relaxing everything, relax the instruction as much as + // possible and emit it as data. + if (getAssembler().getRelaxAll()) { + MCInst Relaxed; + getAssembler().getBackend().RelaxInstruction(Inst, Relaxed); + while (getAssembler().getBackend().MayNeedRelaxation(Relaxed)) + getAssembler().getBackend().RelaxInstruction(Relaxed, Relaxed); + EmitInstToData(Relaxed); + return; + } + + // Otherwise emit to a separate fragment. + EmitInstToFragment(Inst); } void MCMachOStreamer::Finish() { - Assembler.Finish(); + // Dump out the dwarf file & directory tables and line tables. + if (getContext().hasDwarfFiles()) { + const MCSection *DwarfLineSection = getContext().getMachOSection("__DWARF", + "__debug_line", + MCSectionMachO::S_ATTR_DEBUG, + 0, SectionKind::getDataRelLocal()); + MCDwarfFileTable::Emit(this, DwarfLineSection); + } + + // We have to set the fragment atom associations so we can relax properly for + // Mach-O. + + // First, scan the symbol table to build a lookup table from fragments to + // defining symbols. + DenseMap DefiningSymbolMap; + for (MCAssembler::symbol_iterator it = getAssembler().symbol_begin(), + ie = getAssembler().symbol_end(); it != ie; ++it) { + if (getAssembler().isSymbolLinkerVisible(it->getSymbol()) && + it->getFragment()) { + // An atom defining symbol should never be internal to a fragment. + assert(it->getOffset() == 0 && "Invalid offset in atom defining symbol!"); + DefiningSymbolMap[it->getFragment()] = it; + } + } + + // Set the fragment atom associations by tracking the last seen atom defining + // symbol. + for (MCAssembler::iterator it = getAssembler().begin(), + ie = getAssembler().end(); it != ie; ++it) { + MCSymbolData *CurrentAtom = 0; + for (MCSectionData::iterator it2 = it->begin(), + ie2 = it->end(); it2 != ie2; ++it2) { + if (MCSymbolData *SD = DefiningSymbolMap.lookup(it2)) + CurrentAtom = SD; + it2->setAtom(CurrentAtom); + } + } + + this->MCObjectStreamer::Finish(); } -MCStreamer *llvm::createMachOStreamer(MCContext &Context, raw_ostream &OS, - MCCodeEmitter *CE) { - return new MCMachOStreamer(Context, OS, CE); +MCStreamer *llvm::createMachOStreamer(MCContext &Context, TargetAsmBackend &TAB, + raw_ostream &OS, MCCodeEmitter *CE, + bool RelaxAll) { + MCMachOStreamer *S = new MCMachOStreamer(Context, TAB, OS, CE); + if (RelaxAll) + S->getAssembler().setRelaxAll(true); + return S; }