X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FMC%2FMCELFStreamer.cpp;h=bdc4a8410fb226b3c83b8be300a15a2b497e4fff;hp=e9afff6bed4c40e49ea2d0abbf109bfdd7c39a5b;hb=d8ee23f34c2f4b8472f406067140cb4d37c19cab;hpb=6c1d4972cf1cd6b6072e31c05f97abb1ed7a8497 diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp index e9afff6bed4..bdc4a8410fb 100644 --- a/lib/MC/MCELFStreamer.cpp +++ b/lib/MC/MCELFStreamer.cpp @@ -1,4 +1,4 @@ -//===- lib/MC/MCELFStreamer.cpp - ELF Object Output ------------===// +//===- lib/MC/MCELFStreamer.cpp - ELF Object Output -----------------------===// // // The LLVM Compiler Infrastructure // @@ -12,7 +12,10 @@ //===----------------------------------------------------------------------===// #include "llvm/MC/MCELFStreamer.h" +#include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/MC/MCAsmBackend.h" +#include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCContext.h" @@ -20,6 +23,7 @@ #include "llvm/MC/MCELFSymbolFlags.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCInst.h" +#include "llvm/MC/MCObjectFileInfo.h" #include "llvm/MC/MCObjectStreamer.h" #include "llvm/MC/MCSection.h" #include "llvm/MC/MCSectionELF.h" @@ -32,46 +36,26 @@ using namespace llvm; - -inline void MCELFStreamer::SetSection(StringRef Section, unsigned Type, - unsigned Flags, SectionKind Kind) { - SwitchSection(getContext().getELFSection(Section, Type, Flags, Kind)); +MCELFStreamer::~MCELFStreamer() { } -inline void MCELFStreamer::SetSectionData() { - SetSection(".data", - ELF::SHT_PROGBITS, - ELF::SHF_WRITE | ELF::SHF_ALLOC, - SectionKind::getDataRel()); - EmitCodeAlignment(4, 0); -} +void MCELFStreamer::InitSections(bool NoExecStack) { + // This emulates the same behavior of GNU as. This makes it easier + // to compare the output as the major sections are in the same order. + MCContext &Ctx = getContext(); + SwitchSection(Ctx.getObjectFileInfo()->getTextSection()); + EmitCodeAlignment(4); -inline void MCELFStreamer::SetSectionText() { - SetSection(".text", - ELF::SHT_PROGBITS, - ELF::SHF_EXECINSTR | ELF::SHF_ALLOC, - SectionKind::getText()); - EmitCodeAlignment(4, 0); -} + SwitchSection(Ctx.getObjectFileInfo()->getDataSection()); + EmitCodeAlignment(4); -inline void MCELFStreamer::SetSectionBss() { - SetSection(".bss", - ELF::SHT_NOBITS, - ELF::SHF_WRITE | ELF::SHF_ALLOC, - SectionKind::getBSS()); - EmitCodeAlignment(4, 0); -} + SwitchSection(Ctx.getObjectFileInfo()->getBSSSection()); + EmitCodeAlignment(4); -MCELFStreamer::~MCELFStreamer() { -} + SwitchSection(Ctx.getObjectFileInfo()->getTextSection()); -void MCELFStreamer::InitSections() { - // This emulates the same behavior of GNU as. This makes it easier - // to compare the output as the major sections are in the same order. - SetSectionText(); - SetSectionData(); - SetSectionBss(); - SetSectionText(); + if (NoExecStack) + SwitchSection(Ctx.getAsmInfo()->getNonexecutableStackSection(Ctx)); } void MCELFStreamer::EmitLabel(MCSymbol *Symbol) { @@ -86,11 +70,10 @@ void MCELFStreamer::EmitLabel(MCSymbol *Symbol) { MCELF::SetType(SD, ELF::STT_TLS); } -void MCELFStreamer::EmitDebugLabel(MCSymbol *Symbol) { - EmitLabel(Symbol); -} - void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) { + // Let the target do whatever target specific stuff it needs to do. + getAssembler().getBackend().handleAssemblerFlag(Flag); + // Do any generic stuff we need to do. switch (Flag) { case MCAF_SyntaxUnified: return; // no-op here. case MCAF_Code16: return; // Change parsing mode; no-op here. @@ -104,26 +87,55 @@ void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) { llvm_unreachable("invalid assembler flag!"); } -void MCELFStreamer::ChangeSection(const MCSection *Section) { +void MCELFStreamer::ChangeSection(const MCSection *Section, + const MCExpr *Subsection) { MCSectionData *CurSection = getCurrentSectionData(); if (CurSection && CurSection->isBundleLocked()) report_fatal_error("Unterminated .bundle_lock when changing a section"); - const MCSymbol *Grp = static_cast(Section)->getGroup(); + + MCAssembler &Asm = getAssembler(); + auto *SectionELF = static_cast(Section); + const MCSymbol *Grp = SectionELF->getGroup(); if (Grp) - getAssembler().getOrCreateSymbolData(*Grp); - this->MCObjectStreamer::ChangeSection(Section); + Asm.getOrCreateSymbolData(*Grp); + + this->MCObjectStreamer::ChangeSection(Section, Subsection); + MCSymbol *SectionSymbol = getContext().getOrCreateSectionSymbol(*SectionELF); + if (SectionSymbol->isUndefined()) { + EmitLabel(SectionSymbol); + MCELF::SetType(Asm.getSymbolData(*SectionSymbol), ELF::STT_SECTION); + } } void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) { getAssembler().getOrCreateSymbolData(*Symbol); - MCSymbolData &AliasSD = getAssembler().getOrCreateSymbolData(*Alias); - AliasSD.setFlags(AliasSD.getFlags() | ELF_Other_Weakref); - const MCExpr *Value = MCSymbolRefExpr::Create(Symbol, getContext()); + const MCExpr *Value = MCSymbolRefExpr::Create( + Symbol, MCSymbolRefExpr::VK_WEAKREF, getContext()); Alias->setVariableValue(Value); } -void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, - MCSymbolAttr Attribute) { +// When GNU as encounters more than one .type declaration for an object it seems +// to use a mechanism similar to the one below to decide which type is actually +// used in the object file. The greater of T1 and T2 is selected based on the +// following ordering: +// STT_NOTYPE < STT_OBJECT < STT_FUNC < STT_GNU_IFUNC < STT_TLS < anything else +// If neither T1 < T2 nor T2 < T1 according to this ordering, use T2 (the user +// provided type). +static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) { + unsigned TypeOrdering[] = {ELF::STT_NOTYPE, ELF::STT_OBJECT, ELF::STT_FUNC, + ELF::STT_GNU_IFUNC, ELF::STT_TLS}; + for (unsigned i = 0; i != array_lengthof(TypeOrdering); ++i) { + if (T1 == TypeOrdering[i]) + return T2; + if (T2 == TypeOrdering[i]) + return T1; + } + + return T2; +} + +bool MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, + MCSymbolAttr Attribute) { // Indirect symbols are handled differently, to match how 'as' handles // them. This makes writing matching .o files easier. if (Attribute == MCSA_IndirectSymbol) { @@ -133,7 +145,7 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, ISD.Symbol = Symbol; ISD.SectionData = getCurrentSectionData(); getAssembler().getIndirectSymbols().push_back(ISD); - return; + return true; } // Adding a symbol attribute always introduces the symbol, note that an @@ -156,7 +168,7 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, case MCSA_WeakDefAutoPrivate: case MCSA_Invalid: case MCSA_IndirectSymbol: - llvm_unreachable("Invalid symbol attribute for ELF!"); + return false; case MCSA_NoDeadStrip: case MCSA_ELF_TypeGnuUniqueObject: @@ -183,27 +195,34 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, break; case MCSA_ELF_TypeFunction: - MCELF::SetType(SD, ELF::STT_FUNC); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_FUNC)); break; case MCSA_ELF_TypeIndFunction: - MCELF::SetType(SD, ELF::STT_GNU_IFUNC); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_GNU_IFUNC)); break; case MCSA_ELF_TypeObject: - MCELF::SetType(SD, ELF::STT_OBJECT); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_OBJECT)); break; case MCSA_ELF_TypeTLS: - MCELF::SetType(SD, ELF::STT_TLS); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_TLS)); break; case MCSA_ELF_TypeCommon: - MCELF::SetType(SD, ELF::STT_COMMON); + // TODO: Emit these as a common symbol. + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_OBJECT)); break; case MCSA_ELF_TypeNoType: - MCELF::SetType(SD, ELF::STT_NOTYPE); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_NOTYPE)); break; case MCSA_Protected: @@ -218,6 +237,8 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, MCELF::SetVisibility(SD, ELF::STV_INTERNAL); break; } + + return true; } void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, @@ -237,7 +258,8 @@ void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, ELF::SHF_WRITE | ELF::SHF_ALLOC, SectionKind::getBSS()); - Symbol->setSection(*Section); + + AssignSection(Symbol, Section); struct LocalCommon L = {&SD, Size, ByteAlignment}; LocalCommons.push_back(L); @@ -264,11 +286,11 @@ void MCELFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size, } void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size, - unsigned AddrSpace) { + const SMLoc &Loc) { if (getCurrentSectionData()->isBundleLocked()) report_fatal_error("Emitting values inside a locked bundle is forbidden"); fixSymbolsInTLSFixups(Value); - MCObjectStreamer::EmitValueImpl(Value, Size, AddrSpace); + MCObjectStreamer::EmitValueImpl(Value, Size, Loc); } void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment, @@ -281,22 +303,33 @@ void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment, ValueSize, MaxBytesToEmit); } - -// Add a symbol for the file name of this module. This is the second -// entry in the module's symbol table (the first being the null symbol). +// Add a symbol for the file name of this module. They start after the +// null symbol and don't count as normal symbol, i.e. a non-STT_FILE symbol +// with the same name may appear. void MCELFStreamer::EmitFileDirective(StringRef Filename) { - MCSymbol *Symbol = getAssembler().getContext().GetOrCreateSymbol(Filename); - Symbol->setSection(*getCurrentSection()); - Symbol->setAbsolute(); - - MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); - - SD.setFlags(ELF_STT_File | ELF_STB_Local | ELF_STV_Default); + getAssembler().addFileName(Filename); +} + +void MCELFStreamer::EmitIdent(StringRef IdentString) { + const MCSection *Comment = getAssembler().getContext().getELFSection( + ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, + SectionKind::getReadOnly(), 1, ""); + PushSection(); + SwitchSection(Comment); + if (!SeenIdent) { + EmitIntValue(0, 1); + SeenIdent = true; + } + EmitBytes(IdentString); + EmitIntValue(0, 1); + PopSection(); } -void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) { +void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) { switch (expr->getKind()) { - case MCExpr::Target: llvm_unreachable("Can't handle target exprs yet!"); + case MCExpr::Target: + cast(expr)->fixELFSymbolsInTLSFixups(getAssembler()); + break; case MCExpr::Constant: break; @@ -321,13 +354,46 @@ void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) { case MCSymbolRefExpr::VK_TLSLDM: case MCSymbolRefExpr::VK_TPOFF: case MCSymbolRefExpr::VK_DTPOFF: - case MCSymbolRefExpr::VK_ARM_TLSGD: - case MCSymbolRefExpr::VK_ARM_TPOFF: - case MCSymbolRefExpr::VK_ARM_GOTTPOFF: case MCSymbolRefExpr::VK_Mips_TLSGD: case MCSymbolRefExpr::VK_Mips_GOTTPREL: case MCSymbolRefExpr::VK_Mips_TPREL_HI: case MCSymbolRefExpr::VK_Mips_TPREL_LO: + case MCSymbolRefExpr::VK_PPC_DTPMOD: + case MCSymbolRefExpr::VK_PPC_TPREL: + case MCSymbolRefExpr::VK_PPC_TPREL_LO: + case MCSymbolRefExpr::VK_PPC_TPREL_HI: + case MCSymbolRefExpr::VK_PPC_TPREL_HA: + case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER: + case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA: + case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST: + case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA: + case MCSymbolRefExpr::VK_PPC_DTPREL: + case MCSymbolRefExpr::VK_PPC_DTPREL_LO: + case MCSymbolRefExpr::VK_PPC_DTPREL_HI: + case MCSymbolRefExpr::VK_PPC_DTPREL_HA: + case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER: + case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA: + case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST: + case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA: + case MCSymbolRefExpr::VK_PPC_GOT_TPREL: + case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: + case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI: + case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA: + case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: + case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: + case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI: + case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA: + case MCSymbolRefExpr::VK_PPC_TLS: + case MCSymbolRefExpr::VK_PPC_GOT_TLSGD: + case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO: + case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI: + case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA: + case MCSymbolRefExpr::VK_PPC_TLSGD: + case MCSymbolRefExpr::VK_PPC_GOT_TLSLD: + case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO: + case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI: + case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA: + case MCSymbolRefExpr::VK_PPC_TLSLD: break; } MCSymbolData &SD = getAssembler().getOrCreateSymbolData(symRef.getSymbol()); @@ -341,20 +407,22 @@ void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) { } } -void MCELFStreamer::EmitInstToFragment(const MCInst &Inst) { - this->MCObjectStreamer::EmitInstToFragment(Inst); - MCInstFragment &F = *cast(getCurrentFragment()); +void MCELFStreamer::EmitInstToFragment(const MCInst &Inst, + const MCSubtargetInfo &STI) { + this->MCObjectStreamer::EmitInstToFragment(Inst, STI); + MCRelaxableFragment &F = *cast(getCurrentFragment()); for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i) fixSymbolsInTLSFixups(F.getFixups()[i].getValue()); } -void MCELFStreamer::EmitInstToData(const MCInst &Inst) { +void MCELFStreamer::EmitInstToData(const MCInst &Inst, + const MCSubtargetInfo &STI) { MCAssembler &Assembler = getAssembler(); SmallVector Fixups; SmallString<256> Code; raw_svector_ostream VecOS(Code); - Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups); + Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups, STI); VecOS.flush(); for (unsigned i = 0, e = Fixups.size(); i != e; ++i) @@ -367,8 +435,10 @@ void MCELFStreamer::EmitInstToData(const MCInst &Inst) { // data fragment). // // If bundling is enabled: - // - If we're not in a bundle-locked group, emit the instruction into a data - // fragment of its own. + // - If we're not in a bundle-locked group, emit the instruction into a + // fragment of its own. If there are no fixups registered for the + // instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a + // MCDataFragment. // - If we're in a bundle-locked group, append the instruction to the current // data fragment because we want all the instructions in a group to get into // the same fragment. Be careful not to do that for the first instruction in @@ -378,14 +448,27 @@ void MCELFStreamer::EmitInstToData(const MCInst &Inst) { if (Assembler.isBundlingEnabled()) { MCSectionData *SD = getCurrentSectionData(); if (SD->isBundleLocked() && !SD->isBundleGroupBeforeFirstInst()) - DF = getOrCreateDataFragment(); - else { - DF = new MCDataFragment(SD); - if (SD->getBundleLockState() == MCSectionData::BundleLockedAlignToEnd) { - // If this is a new fragment created for a bundle-locked group, and the - // group was marked as "align_to_end", set a flag in the fragment. - DF->setAlignToBundleEnd(true); - } + // If we are bundle-locked, we re-use the current fragment. + // The bundle-locking directive ensures this is a new data fragment. + DF = cast(getCurrentFragment()); + else if (!SD->isBundleLocked() && Fixups.size() == 0) { + // Optimize memory usage by emitting the instruction to a + // MCCompactEncodedInstFragment when not in a bundle-locked group and + // there are no fixups registered. + MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment(); + insert(CEIF); + CEIF->getContents().append(Code.begin(), Code.end()); + return; + } else { + DF = new MCDataFragment(); + insert(DF); + } + if (SD->getBundleLockState() == MCSectionData::BundleLockedAlignToEnd) { + // If this fragment is for a group marked "align_to_end", set a flag + // in the fragment. This can happen after the fragment has already been + // created if there are nested bundle_align groups and an inner one + // is the one marked align_to_end. + DF->setAlignToBundleEnd(true); } // We're now emitting an instruction in a bundle group, so this flag has @@ -407,10 +490,11 @@ void MCELFStreamer::EmitInstToData(const MCInst &Inst) { void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) { assert(AlignPow2 <= 30 && "Invalid bundle alignment"); MCAssembler &Assembler = getAssembler(); - if (Assembler.getBundleAlignSize() == 0 && AlignPow2 > 0) - Assembler.setBundleAlignSize(1 << AlignPow2); + if (AlignPow2 > 0 && (Assembler.getBundleAlignSize() == 0 || + Assembler.getBundleAlignSize() == 1U << AlignPow2)) + Assembler.setBundleAlignSize(1U << AlignPow2); else - report_fatal_error(".bundle_align_mode should be only set once per file"); + report_fatal_error(".bundle_align_mode cannot be changed once set"); } void MCELFStreamer::EmitBundleLock(bool AlignToEnd) { @@ -420,12 +504,12 @@ void MCELFStreamer::EmitBundleLock(bool AlignToEnd) { // if (!getAssembler().isBundlingEnabled()) report_fatal_error(".bundle_lock forbidden when bundling is disabled"); - else if (SD->isBundleLocked()) - report_fatal_error("Nesting of .bundle_lock is forbidden"); + + if (!SD->isBundleLocked()) + SD->setBundleGroupBeforeFirstInst(true); SD->setBundleLockState(AlignToEnd ? MCSectionData::BundleLockedAlignToEnd : MCSectionData::BundleLocked); - SD->setBundleGroupBeforeFirstInst(true); } void MCELFStreamer::EmitBundleUnlock() { @@ -442,9 +526,7 @@ void MCELFStreamer::EmitBundleUnlock() { SD->setBundleLockState(MCSectionData::NotBundleLocked); } -void MCELFStreamer::FinishImpl() { - EmitFrames(true); - +void MCELFStreamer::Flush() { for (std::vector::const_iterator i = LocalCommons.begin(), e = LocalCommons.end(); i != e; ++i) { @@ -465,21 +547,23 @@ void MCELFStreamer::FinishImpl() { SectData.setAlignment(ByteAlignment); } - this->MCObjectStreamer::FinishImpl(); + LocalCommons.clear(); } -void MCELFStreamer::EmitTCEntry(const MCSymbol &S) { - // Creates a R_PPC64_TOC relocation - MCObjectStreamer::EmitSymbolValue(&S, 8, 0); + +void MCELFStreamer::FinishImpl() { + EmitFrames(nullptr); + + Flush(); + + this->MCObjectStreamer::FinishImpl(); } MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB, raw_ostream &OS, MCCodeEmitter *CE, - bool RelaxAll, bool NoExecStack) { + bool RelaxAll) { MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE); if (RelaxAll) S->getAssembler().setRelaxAll(true); - if (NoExecStack) - S->getAssembler().setNoExecStack(true); return S; }