X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCMachOStreamer.cpp;h=a10a63ee6a42286fc00ec4c0bdf462c81662d624;hb=345ed9806a0ab5d680da1ff78fe3df7ebbc6107d;hp=4329221babb1438e0736de7121c017744f6bac17;hpb=011c3f110bca748db66e437924f936a62f1969bf;p=oota-llvm.git diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp index 4329221babb..a10a63ee6a4 100644 --- a/lib/MC/MCMachOStreamer.cpp +++ b/lib/MC/MCMachOStreamer.cpp @@ -14,9 +14,13 @@ #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/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" @@ -25,80 +29,20 @@ using namespace llvm; namespace { -class MCMachOStreamer : public MCStreamer { - +class MCMachOStreamer : public MCObjectStreamer { private: - MCAssembler Assembler; - MCSectionData *CurSectionData; - - /// Track the current atom for each section. - DenseMap CurrentAtomMap; - -private: - MCFragment *getCurrentFragment() const { - assert(CurSectionData && "No current section!"); - - if (!CurSectionData->empty()) - return &CurSectionData->getFragmentList().back(); - - return 0; - } - - /// Get a data fragment to write into, creating a new one if the current - /// fragment is not a data fragment. - MCDataFragment *getOrCreateDataFragment() const { - MCDataFragment *F = dyn_cast_or_null(getCurrentFragment()); - if (!F) - F = createDataFragment(); - return F; - } - - /// Create a new data fragment in the current section. - MCDataFragment *createDataFragment() const { - MCDataFragment *DF = new MCDataFragment(CurSectionData); - DF->setAtom(CurrentAtomMap.lookup(CurSectionData)); - return DF; - } + void EmitInstToFragment(const MCInst &Inst); + void EmitInstToData(const MCInst &Inst); public: MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB, - raw_ostream &_OS, MCCodeEmitter *_Emitter) - : MCStreamer(Context), Assembler(Context, TAB, *_Emitter, _OS), - CurSectionData(0) {} - ~MCMachOStreamer() {} - - MCAssembler &getAssembler() { return Assembler; } - - const MCExpr *AddValueSymbols(const MCExpr *Value) { - switch (Value->getKind()) { - case MCExpr::Target: assert(0 && "Can't handle target exprs yet!"); - case MCExpr::Constant: - break; - - case MCExpr::Binary: { - const MCBinaryExpr *BE = cast(Value); - AddValueSymbols(BE->getLHS()); - AddValueSymbols(BE->getRHS()); - break; - } - - case MCExpr::SymbolRef: - Assembler.getOrCreateSymbolData( - cast(Value)->getSymbol()); - break; - - case MCExpr::Unary: - AddValueSymbols(cast(Value)->getSubExpr()); - break; - } - - return Value; - } + 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); @@ -140,15 +84,22 @@ public: unsigned MaxBytesToEmit = 0); virtual void EmitValueToOffset(const MCExpr *Offset, unsigned char Value = 0); - + virtual void EmitFileDirective(StringRef Filename) { - report_fatal_error("unsupported directive: '.file'"); + // 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) { - report_fatal_error("unsupported directive: '.file'"); + // 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(); /// @} @@ -156,38 +107,34 @@ 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 = &Assembler.getOrCreateSectionData(*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!"); - MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol); + Symbol->setSection(*CurSection); - // Update the current atom map, if necessary. - bool MustCreateFragment = false; - if (Assembler.isSymbolLinkerVisible(&SD)) { - CurrentAtomMap[CurSectionData] = &SD; + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); - // We have to create a new fragment, fragments cannot span atoms. - MustCreateFragment = true; - } + // 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()); // 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 = - MustCreateFragment ? createDataFragment() : getOrCreateDataFragment(); + MCDataFragment *F = getOrCreateDataFragment(); assert(!SD.getFragment() && "Unexpected fragment on symbol data!"); SD.setFragment(F); SD.setOffset(F->getContents().size()); @@ -200,23 +147,23 @@ void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) { // 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); - - Symbol->setSection(*CurSection); } 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) { + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. // FIXME: Lift context changes into super class. - Assembler.getOrCreateSymbolData(*Symbol); + getAssembler().getOrCreateSymbolData(*Symbol); Symbol->setVariableValue(AddValueSymbols(Value)); } @@ -229,15 +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 getOrCreateSymbolData here is to register // the symbol with the assembler. - MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol); + 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 @@ -303,14 +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!"); - Assembler.getOrCreateSymbolData(*Symbol).setFlags(DescValue&SF_DescFlagsMask); + getAssembler().getOrCreateSymbolData(*Symbol).setFlags( + DescValue & SF_DescFlagsMask); } void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, @@ -318,14 +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 = Assembler.getOrCreateSymbolData(*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 = Assembler.getOrCreateSectionData(*Section); + MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section); // The symbol may not be present, which only creates the section. if (!Symbol) @@ -335,7 +287,7 @@ void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol, assert(Symbol->isUndefined() && "Cannot define a symbol twice!"); - MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol); + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); // Emit an align fragment if necessary. if (ByteAlignment != 1) @@ -343,8 +295,6 @@ void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol, MCFragment *F = new MCFillFragment(0, 0, Size, &SectData); SD.setFragment(F); - if (Assembler.isSymbolLinkerVisible(&SD)) - F->setAtom(&SD); Symbol->setSection(*Section); @@ -353,7 +303,8 @@ void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol, SectData.setAlignment(ByteAlignment); } -// This should always be called with the thread local bss section. +// 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); @@ -361,11 +312,15 @@ void MCMachOStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, } void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) { + // 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) { + // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into + // MCObjectStreamer. MCDataFragment *DF = getOrCreateDataFragment(); // Avoid fixups when possible. @@ -375,8 +330,9 @@ void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size, for (unsigned i = 0; i != Size; ++i) DF->getContents().push_back(uint8_t(AbsValue >> (i * 8))); } else { - DF->addFixup(MCAsmFixup(DF->getContents().size(), *AddValueSymbols(Value), - MCFixup::getKindForSize(Size))); + DF->addFixup(MCFixup::Create(DF->getContents().size(), + AddValueSymbols(Value), + MCFixup::getKindForSize(Size))); DF->getContents().resize(DF->getContents().size() + Size, 0); } } @@ -384,100 +340,145 @@ void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size, 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; - MCFragment *F = new MCAlignFragment(ByteAlignment, Value, ValueSize, - MaxBytesToEmit, CurSectionData); - F->setAtom(CurrentAtomMap.lookup(CurSectionData)); + new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit, + getCurrentSectionData()); // 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::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, - CurSectionData); + getCurrentSectionData()); F->setEmitNops(true); - F->setAtom(CurrentAtomMap.lookup(CurSectionData)); // 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) { - MCFragment *F = new MCOrgFragment(*Offset, Value, CurSectionData); - F->setAtom(CurrentAtomMap.lookup(CurSectionData)); + new MCOrgFragment(*Offset, Value, getCurrentSectionData()); } -void MCMachOStreamer::EmitInstruction(const MCInst &Inst) { - // Scan for values. - for (unsigned i = Inst.getNumOperands(); i--; ) - if (Inst.getOperand(i).isExpr()) - AddValueSymbols(Inst.getOperand(i).getExpr()); +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(); - CurSectionData->setHasInstructions(true); + IF->getCode() = Code; + IF->getFixups() = Fixups; +} - // FIXME-PERF: Common case is that we don't need to relax, encode directly - // onto the data fragments buffers. +void MCMachOStreamer::EmitInstToData(const MCInst &Inst) { + MCDataFragment *DF = getOrCreateDataFragment(); SmallVector Fixups; SmallString<256> Code; raw_svector_ostream VecOS(Code); - Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups); + getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups); VecOS.flush(); - // FIXME: Eliminate this copy. - SmallVector AsmFixups; + // Add the fixups and data. for (unsigned i = 0, e = Fixups.size(); i != e; ++i) { - MCFixup &F = Fixups[i]; - AsmFixups.push_back(MCAsmFixup(F.getOffset(), *F.getValue(), - F.getKind())); + Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size()); + DF->addFixup(Fixups[i]); } + DF->getContents().append(Code.begin(), Code.end()); +} - // See if we might need to relax this instruction, if so it needs its own - // fragment. - // - // FIXME-PERF: Support target hook to do a fast path that avoids the encoder, - // when we can immediately tell that we will get something which might need - // relaxation (and compute its size). - // - // FIXME-PERF: We should also be smart about immediately relaxing instructions - // which we can already show will never possibly fit (we can also do a very - // good job of this before we do the first relaxation pass, because we have - // total knowledge about undefined symbols at that point). Even now, though, - // we can do a decent job, especially on Darwin where scattering means that we - // are going to often know that we can never fully resolve a fixup. - if (Assembler.getBackend().MayNeedRelaxation(Inst, AsmFixups)) { - MCInstFragment *IF = new MCInstFragment(Inst, CurSectionData); - IF->setAtom(CurrentAtomMap.lookup(CurSectionData)); - - // 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. - IF->getCode() = Code; - IF->getFixups() = AsmFixups; +void MCMachOStreamer::EmitInstruction(const MCInst &Inst) { + // Scan for values. + for (unsigned i = Inst.getNumOperands(); i--; ) + if (Inst.getOperand(i).isExpr()) + AddValueSymbols(Inst.getOperand(i).getExpr()); + + getCurrentSectionData()->setHasInstructions(true); + // 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; } - // Add the fixups and data. - MCDataFragment *DF = getOrCreateDataFragment(); - for (unsigned i = 0, e = AsmFixups.size(); i != e; ++i) { - AsmFixups[i].Offset += DF->getContents().size(); - DF->addFixup(AsmFixups[i]); + // 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; } - DF->getContents().append(Code.begin(), Code.end()); + + // 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, TargetAsmBackend &TAB,