X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCAssembler.cpp;h=143d284897f3d93494db12fa2cac5dfd7a0f05ae;hb=0eba49c22e81ffb6aa9290684f383e7352f00574;hp=b8a4b438f6ccd3b6a1a9600e49a5a3d93f01508e;hpb=2ddea4b44d7d0f8b016d49bd8a16146f84a2a27e;p=oota-llvm.git diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp index b8a4b438f6c..143d284897f 100644 --- a/lib/MC/MCAssembler.cpp +++ b/lib/MC/MCAssembler.cpp @@ -7,12 +7,12 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "assembler" #include "llvm/MC/MCAssembler.h" #include "llvm/ADT/Statistic.h" #include "llvm/ADT/StringExtras.h" #include "llvm/ADT/Twine.h" #include "llvm/MC/MCAsmBackend.h" +#include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCAsmLayout.h" #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCContext.h" @@ -21,6 +21,7 @@ #include "llvm/MC/MCFixupKindInfo.h" #include "llvm/MC/MCObjectWriter.h" #include "llvm/MC/MCSection.h" +#include "llvm/MC/MCSectionELF.h" #include "llvm/MC/MCSymbol.h" #include "llvm/MC/MCValue.h" #include "llvm/Support/Debug.h" @@ -28,9 +29,11 @@ #include "llvm/Support/LEB128.h" #include "llvm/Support/TargetRegistry.h" #include "llvm/Support/raw_ostream.h" - +#include using namespace llvm; +#define DEBUG_TYPE "assembler" + namespace { namespace stats { STATISTIC(EmittedFragments, "Number of emitted assembler fragments - total"); @@ -65,20 +68,20 @@ MCAsmLayout::MCAsmLayout(MCAssembler &Asm) : Assembler(Asm), LastValidFragment() { // Compute the section layout order. Virtual sections must go last. - for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) - if (!it->getSection().isVirtualSection()) - SectionOrder.push_back(&*it); - for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) - if (it->getSection().isVirtualSection()) - SectionOrder.push_back(&*it); + for (MCSection &Sec : Asm) + if (!Sec.isVirtualSection()) + SectionOrder.push_back(&Sec); + for (MCSection &Sec : Asm) + if (Sec.isVirtualSection()) + SectionOrder.push_back(&Sec); } bool MCAsmLayout::isFragmentValid(const MCFragment *F) const { - const MCSectionData &SD = *F->getParent(); - const MCFragment *LastValid = LastValidFragment.lookup(&SD); + const MCSection *Sec = F->getParent(); + const MCFragment *LastValid = LastValidFragment.lookup(Sec); if (!LastValid) return false; - assert(LastValid->getParent() == F->getParent()); + assert(LastValid->getParent() == Sec); return F->getLayoutOrder() <= LastValid->getLayoutOrder(); } @@ -89,16 +92,14 @@ void MCAsmLayout::invalidateFragmentsFrom(MCFragment *F) { // Otherwise, reset the last valid fragment to the previous fragment // (if this is the first fragment, it will be NULL). - const MCSectionData &SD = *F->getParent(); - LastValidFragment[&SD] = F->getPrevNode(); + LastValidFragment[F->getParent()] = F->getPrevNode(); } void MCAsmLayout::ensureValid(const MCFragment *F) const { - MCSectionData &SD = *F->getParent(); - - MCFragment *Cur = LastValidFragment[&SD]; + MCSection *Sec = F->getParent(); + MCFragment *Cur = LastValidFragment[Sec]; if (!Cur) - Cur = &*SD.begin(); + Cur = Sec->begin(); else Cur = Cur->getNextNode(); @@ -116,55 +117,111 @@ uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const { return F->Offset; } -uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const { - const MCSymbol &S = SD->getSymbol(); - - // If this is a variable, then recursively evaluate now. - if (S.isVariable()) { - MCValue Target; - if (!S.getVariableValue()->EvaluateAsRelocatable(Target, *this)) - report_fatal_error("unable to evaluate offset for variable '" + +// Simple getSymbolOffset helper for the non-varibale case. +static bool getLabelOffset(const MCAsmLayout &Layout, const MCSymbol &S, + bool ReportError, uint64_t &Val) { + if (!S.getFragment()) { + if (ReportError) + report_fatal_error("unable to evaluate offset to undefined symbol '" + S.getName() + "'"); + return false; + } + Val = Layout.getFragmentOffset(S.getFragment()) + S.getOffset(); + return true; +} - // Verify that any used symbols are defined. - if (Target.getSymA() && Target.getSymA()->getSymbol().isUndefined()) - report_fatal_error("unable to evaluate offset to undefined symbol '" + - Target.getSymA()->getSymbol().getName() + "'"); - if (Target.getSymB() && Target.getSymB()->getSymbol().isUndefined()) - report_fatal_error("unable to evaluate offset to undefined symbol '" + - Target.getSymB()->getSymbol().getName() + "'"); - - uint64_t Offset = Target.getConstant(); - if (Target.getSymA()) - Offset += getSymbolOffset(&Assembler.getSymbolData( - Target.getSymA()->getSymbol())); - if (Target.getSymB()) - Offset -= getSymbolOffset(&Assembler.getSymbolData( - Target.getSymB()->getSymbol())); - return Offset; +static bool getSymbolOffsetImpl(const MCAsmLayout &Layout, const MCSymbol &S, + bool ReportError, uint64_t &Val) { + if (!S.isVariable()) + return getLabelOffset(Layout, S, ReportError, Val); + + // If SD is a variable, evaluate it. + MCValue Target; + if (!S.getVariableValue()->evaluateAsValue(Target, Layout)) + report_fatal_error("unable to evaluate offset for variable '" + + S.getName() + "'"); + + uint64_t Offset = Target.getConstant(); + + const MCSymbolRefExpr *A = Target.getSymA(); + if (A) { + uint64_t ValA; + if (!getLabelOffset(Layout, A->getSymbol(), ReportError, ValA)) + return false; + Offset += ValA; + } + + const MCSymbolRefExpr *B = Target.getSymB(); + if (B) { + uint64_t ValB; + if (!getLabelOffset(Layout, B->getSymbol(), ReportError, ValB)) + return false; + Offset -= ValB; + } + + Val = Offset; + return true; +} + +bool MCAsmLayout::getSymbolOffset(const MCSymbol &S, uint64_t &Val) const { + return getSymbolOffsetImpl(*this, S, false, Val); +} + +uint64_t MCAsmLayout::getSymbolOffset(const MCSymbol &S) const { + uint64_t Val; + getSymbolOffsetImpl(*this, S, true, Val); + return Val; +} + +const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const { + if (!Symbol.isVariable()) + return &Symbol; + + const MCExpr *Expr = Symbol.getVariableValue(); + MCValue Value; + if (!Expr->evaluateAsValue(Value, *this)) + llvm_unreachable("Invalid Expression"); + + const MCSymbolRefExpr *RefB = Value.getSymB(); + if (RefB) + Assembler.getContext().reportFatalError( + SMLoc(), Twine("symbol '") + RefB->getSymbol().getName() + + "' could not be evaluated in a subtraction expression"); + + const MCSymbolRefExpr *A = Value.getSymA(); + if (!A) + return nullptr; + + const MCSymbol &ASym = A->getSymbol(); + const MCAssembler &Asm = getAssembler(); + if (ASym.isCommon()) { + // FIXME: we should probably add a SMLoc to MCExpr. + Asm.getContext().reportFatalError(SMLoc(), + "Common symbol " + ASym.getName() + + " cannot be used in assignment expr"); } - assert(SD->getFragment() && "Invalid getOffset() on undefined symbol!"); - return getFragmentOffset(SD->getFragment()) + SD->getOffset(); + return &ASym; } -uint64_t MCAsmLayout::getSectionAddressSize(const MCSectionData *SD) const { +uint64_t MCAsmLayout::getSectionAddressSize(const MCSection *Sec) const { // The size is the last fragment's end offset. - const MCFragment &F = SD->getFragmentList().back(); + const MCFragment &F = Sec->getFragmentList().back(); return getFragmentOffset(&F) + getAssembler().computeFragmentSize(*this, F); } -uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const { +uint64_t MCAsmLayout::getSectionFileSize(const MCSection *Sec) const { // Virtual sections have no file size. - if (SD->getSection().isVirtualSection()) + if (Sec->isVirtualSection()) return 0; // Otherwise, the file size is the same as the address space size. - return getSectionAddressSize(SD); + return getSectionAddressSize(Sec); } -uint64_t MCAsmLayout::computeBundlePadding(const MCFragment *F, - uint64_t FOffset, uint64_t FSize) { +uint64_t llvm::computeBundlePadding(const MCAssembler &Assembler, + const MCFragment *F, + uint64_t FOffset, uint64_t FSize) { uint64_t BundleSize = Assembler.getBundleAlignSize(); assert(BundleSize > 0 && "computeBundlePadding should only be called if bundling is enabled"); @@ -197,7 +254,7 @@ uint64_t MCAsmLayout::computeBundlePadding(const MCFragment *F, else { // EndOfFragment > BundleSize return 2 * BundleSize - EndOfFragment; } - } else if (EndOfFragment > BundleSize) + } else if (OffsetInBundle > 0 && EndOfFragment > BundleSize) return BundleSize - OffsetInBundle; else return 0; @@ -205,97 +262,77 @@ uint64_t MCAsmLayout::computeBundlePadding(const MCFragment *F, /* *** */ -MCFragment::MCFragment() : Kind(FragmentType(~0)) { -} - -MCFragment::~MCFragment() { +void ilist_node_traits::deleteNode(MCFragment *V) { + V->destroy(); } -MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent) - : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)) -{ - if (Parent) - Parent->getFragmentList().push_back(this); +MCFragment::MCFragment() : Kind(FragmentType(~0)), HasInstructions(false), + AlignToBundleEnd(false), BundlePadding(0) { } -/* *** */ - -MCEncodedFragment::~MCEncodedFragment() { -} +MCFragment::~MCFragment() { } -/* *** */ - -MCEncodedFragmentWithFixups::~MCEncodedFragmentWithFixups() { -} - -/* *** */ - -MCSectionData::MCSectionData() : Section(0) {} - -MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A) - : Section(&_Section), - Ordinal(~UINT32_C(0)), - Alignment(1), - BundleLockState(NotBundleLocked), BundleGroupBeforeFirstInst(false), - HasInstructions(false) -{ - if (A) - A->getSectionList().push_back(this); +MCFragment::MCFragment(FragmentType Kind, bool HasInstructions, + uint8_t BundlePadding, MCSection *Parent) + : Kind(Kind), HasInstructions(HasInstructions), AlignToBundleEnd(false), + BundlePadding(BundlePadding), Parent(Parent), Atom(nullptr), + Offset(~UINT64_C(0)) { + if (Parent && !isDummy()) + Parent->getFragmentList().push_back(this); } -MCSectionData::iterator -MCSectionData::getSubsectionInsertionPoint(unsigned Subsection) { - if (Subsection == 0 && SubsectionFragmentMap.empty()) - return end(); - - SmallVectorImpl >::iterator MI = - std::lower_bound(SubsectionFragmentMap.begin(), SubsectionFragmentMap.end(), - std::make_pair(Subsection, (MCFragment *)0)); - bool ExactMatch = false; - if (MI != SubsectionFragmentMap.end()) { - ExactMatch = MI->first == Subsection; - if (ExactMatch) - ++MI; - } - iterator IP; - if (MI == SubsectionFragmentMap.end()) - IP = end(); - else - IP = MI->second; - if (!ExactMatch && Subsection != 0) { - // The GNU as documentation claims that subsections have an alignment of 4, - // although this appears not to be the case. - MCFragment *F = new MCDataFragment(); - SubsectionFragmentMap.insert(MI, std::make_pair(Subsection, F)); - getFragmentList().insert(IP, F); - F->setParent(this); +void MCFragment::destroy() { + // First check if we are the sentinal. + if (Kind == FragmentType(~0)) { + delete this; + return; } - return IP; -} - -/* *** */ -MCSymbolData::MCSymbolData() : Symbol(0) {} - -MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, - uint64_t _Offset, MCAssembler *A) - : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset), - IsExternal(false), IsPrivateExtern(false), - CommonSize(0), SymbolSize(0), CommonAlign(0), - Flags(0), Index(0) -{ - if (A) - A->getSymbolList().push_back(this); + switch (Kind) { + case FT_Align: + delete cast(this); + return; + case FT_Data: + delete cast(this); + return; + case FT_CompactEncodedInst: + delete cast(this); + return; + case FT_Fill: + delete cast(this); + return; + case FT_Relaxable: + delete cast(this); + return; + case FT_Org: + delete cast(this); + return; + case FT_Dwarf: + delete cast(this); + return; + case FT_DwarfFrame: + delete cast(this); + return; + case FT_LEB: + delete cast(this); + return; + case FT_SafeSEH: + delete cast(this); + return; + case FT_Dummy: + delete cast(this); + return; + } } /* *** */ MCAssembler::MCAssembler(MCContext &Context_, MCAsmBackend &Backend_, - MCCodeEmitter &Emitter_, MCObjectWriter &Writer_, - raw_ostream &OS_) - : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_), - OS(OS_), BundleAlignSize(0), RelaxAll(false), NoExecStack(false), - SubsectionsViaSymbols(false), ELFHeaderEFlags(0) { + MCCodeEmitter &Emitter_, MCObjectWriter &Writer_) + : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_), + BundleAlignSize(0), RelaxAll(false), SubsectionsViaSymbols(false), + ELFHeaderEFlags(0) { + VersionMinInfo.Major = 0; // Major version == 0 for "none specified" } MCAssembler::~MCAssembler() { @@ -304,20 +341,56 @@ MCAssembler::~MCAssembler() { void MCAssembler::reset() { Sections.clear(); Symbols.clear(); - SectionMap.clear(); - SymbolMap.clear(); IndirectSymbols.clear(); DataRegions.clear(); + LinkerOptions.clear(); + FileNames.clear(); ThumbFuncs.clear(); + BundleAlignSize = 0; RelaxAll = false; - NoExecStack = false; SubsectionsViaSymbols = false; ELFHeaderEFlags = 0; + LOHContainer.reset(); + VersionMinInfo.Major = 0; // reset objects owned by us getBackend().reset(); getEmitter().reset(); getWriter().reset(); + getLOHContainer().reset(); +} + +bool MCAssembler::registerSection(MCSection &Section) { + if (Section.isRegistered()) + return false; + Sections.push_back(&Section); + Section.setIsRegistered(true); + return true; +} + +bool MCAssembler::isThumbFunc(const MCSymbol *Symbol) const { + if (ThumbFuncs.count(Symbol)) + return true; + + if (!Symbol->isVariable()) + return false; + + // FIXME: It looks like gas supports some cases of the form "foo + 2". It + // is not clear if that is a bug or a feature. + const MCExpr *Expr = Symbol->getVariableValue(); + const MCSymbolRefExpr *Ref = dyn_cast(Expr); + if (!Ref) + return false; + + if (Ref->getKind() != MCSymbolRefExpr::VK_None) + return false; + + const MCSymbol &Sym = Ref->getSymbol(); + if (!isThumbFunc(&Sym)) + return false; + + ThumbFuncs.insert(Symbol); // Cache it. + return true; } bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const { @@ -329,27 +402,29 @@ bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const { if (!Symbol.isInSection()) return false; - // Otherwise, check if the section requires symbols even for temporary labels. - return getBackend().doesSectionRequireSymbols(Symbol.getSection()); + if (Symbol.isUsedInReloc()) + return true; + + return false; } -const MCSymbolData *MCAssembler::getAtom(const MCSymbolData *SD) const { +const MCSymbol *MCAssembler::getAtom(const MCSymbol &S) const { // Linker visible symbols define atoms. - if (isSymbolLinkerVisible(SD->getSymbol())) - return SD; + if (isSymbolLinkerVisible(S)) + return &S; // Absolute and undefined symbols have no defining atom. - if (!SD->getFragment()) - return 0; + if (!S.isInSection()) + return nullptr; // Non-linker visible symbols in sections which can't be atomized have no // defining atom. - if (!getBackend().isSectionAtomizable( - SD->getFragment()->getParent()->getSection())) - return 0; + if (!getContext().getAsmInfo()->isSectionAtomizableBySymbols( + *S.getFragment()->getParent())) + return nullptr; // Otherwise, return the atom for the containing fragment. - return SD->getFragment()->getAtom(); + return S.getFragment()->getAtom(); } bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout, @@ -357,8 +432,12 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout, MCValue &Target, uint64_t &Value) const { ++stats::evaluateFixup; - if (!Fixup.getValue()->EvaluateAsRelocatable(Target, Layout)) - getContext().FatalError(Fixup.getLoc(), "expected relocatable expression"); + // FIXME: This code has some duplication with recordRelocation. We should + // probably merge the two into a single callback that tries to evaluate a + // fixup and records a relocation if one is needed. + const MCExpr *Expr = Fixup.getValue(); + if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup)) + getContext().reportFatalError(Fixup.getLoc(), "expected relocatable expression"); bool IsPCRel = Backend.getFixupKindInfo( Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel; @@ -372,14 +451,11 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout, } else { const MCSymbolRefExpr *A = Target.getSymA(); const MCSymbol &SA = A->getSymbol(); - if (A->getKind() != MCSymbolRefExpr::VK_None || - SA.AliasedSymbol().isUndefined()) { + if (A->getKind() != MCSymbolRefExpr::VK_None || SA.isUndefined()) { IsResolved = false; } else { - const MCSymbolData &DataA = getSymbolData(SA); - IsResolved = - getWriter().IsSymbolRefDifferenceFullyResolvedImpl(*this, DataA, - *DF, false, true); + IsResolved = getWriter().isSymbolRefDifferenceFullyResolvedImpl( + *this, SA, *DF, false, true); } } } else { @@ -389,14 +465,14 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout, Value = Target.getConstant(); if (const MCSymbolRefExpr *A = Target.getSymA()) { - const MCSymbol &Sym = A->getSymbol().AliasedSymbol(); + const MCSymbol &Sym = A->getSymbol(); if (Sym.isDefined()) - Value += Layout.getSymbolOffset(&getSymbolData(Sym)); + Value += Layout.getSymbolOffset(Sym); } if (const MCSymbolRefExpr *B = Target.getSymB()) { - const MCSymbol &Sym = B->getSymbol().AliasedSymbol(); + const MCSymbol &Sym = B->getSymbol(); if (Sym.isDefined()) - Value -= Layout.getSymbolOffset(&getSymbolData(Sym)); + Value -= Layout.getSymbolOffset(Sym); } @@ -426,15 +502,20 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout, const MCFragment &F) const { switch (F.getKind()) { case MCFragment::FT_Data: + return cast(F).getContents().size(); case MCFragment::FT_Relaxable: + return cast(F).getContents().size(); case MCFragment::FT_CompactEncodedInst: - return cast(F).getContents().size(); + return cast(F).getContents().size(); case MCFragment::FT_Fill: return cast(F).getSize(); case MCFragment::FT_LEB: return cast(F).getContents().size(); + case MCFragment::FT_SafeSEH: + return 4; + case MCFragment::FT_Align: { const MCAlignFragment &AF = cast(F); unsigned Offset = Layout.getFragmentOffset(&AF); @@ -453,7 +534,7 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout, case MCFragment::FT_Org: { const MCOrgFragment &OF = cast(F); int64_t TargetLocation; - if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, Layout)) + if (!OF.getOffset().evaluateAsAbsolute(TargetLocation, Layout)) report_fatal_error("expected assembly-time absolute expression"); // FIXME: We need a way to communicate this error. @@ -469,6 +550,8 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout, return cast(F).getContents().size(); case MCFragment::FT_DwarfFrame: return cast(F).getContents().size(); + case MCFragment::FT_Dummy: + llvm_unreachable("Should not have been added"); } llvm_unreachable("invalid fragment kind"); @@ -509,15 +592,27 @@ void MCAsmLayout::layoutFragment(MCFragment *F) { // The fragment's offset will point to after the padding, and its computed // size won't include the padding. // + // When the -mc-relax-all flag is used, we optimize bundling by writting the + // padding directly into fragments when the instructions are emitted inside + // the streamer. When the fragment is larger than the bundle size, we need to + // ensure that it's bundle aligned. This means that if we end up with + // multiple fragments, we must emit bundle padding between fragments. + // + // ".align N" is an example of a directive that introduces multiple + // fragments. We could add a special case to handle ".align N" by emitting + // within-fragment padding (which would produce less padding when N is less + // than the bundle size), but for now we don't. + // if (Assembler.isBundlingEnabled() && F->hasInstructions()) { assert(isa(F) && "Only MCEncodedFragment implementations have instructions"); uint64_t FSize = Assembler.computeFragmentSize(*this, *F); - if (FSize > Assembler.getBundleAlignSize()) + if (!Assembler.getRelaxAll() && FSize > Assembler.getBundleAlignSize()) report_fatal_error("Fragment can't be larger than a bundle size"); - uint64_t RequiredBundlePadding = computeBundlePadding(F, F->Offset, FSize); + uint64_t RequiredBundlePadding = computeBundlePadding(Assembler, F, + F->Offset, FSize); if (RequiredBundlePadding > UINT8_MAX) report_fatal_error("Padding cannot exceed 255 bytes"); F->setBundlePadding(static_cast(RequiredBundlePadding)); @@ -525,31 +620,28 @@ void MCAsmLayout::layoutFragment(MCFragment *F) { } } -/// \brief Write the contents of a fragment to the given object writer. Expects -/// a MCEncodedFragment. -static void writeFragmentContents(const MCFragment &F, MCObjectWriter *OW) { - const MCEncodedFragment &EF = cast(F); - OW->WriteBytes(EF.getContents()); +void MCAssembler::registerSymbol(const MCSymbol &Symbol, bool *Created) { + bool New = !Symbol.isRegistered(); + if (Created) + *Created = New; + if (New) { + Symbol.setIsRegistered(true); + Symbols.push_back(&Symbol); + } } -/// \brief Write the fragment \p F to the output file. -static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCFragment &F) { - MCObjectWriter *OW = &Asm.getWriter(); - - // FIXME: Embed in fragments instead? - uint64_t FragmentSize = Asm.computeFragmentSize(Layout, F); - +void MCAssembler::writeFragmentPadding(const MCFragment &F, uint64_t FSize, + MCObjectWriter *OW) const { // Should NOP padding be written out before this fragment? unsigned BundlePadding = F.getBundlePadding(); if (BundlePadding > 0) { - assert(Asm.isBundlingEnabled() && + assert(isBundlingEnabled() && "Writing bundle padding with disabled bundling"); assert(F.hasInstructions() && "Writing bundle padding for a fragment without instructions"); - unsigned TotalLength = BundlePadding + static_cast(FragmentSize); - if (F.alignToBundleEnd() && TotalLength > Asm.getBundleAlignSize()) { + unsigned TotalLength = BundlePadding + static_cast(FSize); + if (F.alignToBundleEnd() && TotalLength > getBundleAlignSize()) { // If the padding itself crosses a bundle boundary, it must be emitted // in 2 pieces, since even nop instructions must not cross boundaries. // v--------------v <- BundleAlignSize @@ -558,16 +650,27 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, // | Prev |####|####| F | // ---------------------------- // ^-------------------^ <- TotalLength - unsigned DistanceToBoundary = TotalLength - Asm.getBundleAlignSize(); - if (!Asm.getBackend().writeNopData(DistanceToBoundary, OW)) + unsigned DistanceToBoundary = TotalLength - getBundleAlignSize(); + if (!getBackend().writeNopData(DistanceToBoundary, OW)) report_fatal_error("unable to write NOP sequence of " + Twine(DistanceToBoundary) + " bytes"); BundlePadding -= DistanceToBoundary; } - if (!Asm.getBackend().writeNopData(BundlePadding, OW)) + if (!getBackend().writeNopData(BundlePadding, OW)) report_fatal_error("unable to write NOP sequence of " + Twine(BundlePadding) + " bytes"); } +} + +/// \brief Write the fragment \p F to the output file. +static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFragment &F) { + MCObjectWriter *OW = &Asm.getWriter(); + + // FIXME: Embed in fragments instead? + uint64_t FragmentSize = Asm.computeFragmentSize(Layout, F); + + Asm.writeFragmentPadding(F, FragmentSize, OW); // This variable (and its dummy usage) is to participate in the assert at // the end of the function. @@ -608,10 +711,10 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, for (uint64_t i = 0; i != Count; ++i) { switch (AF.getValueSize()) { default: llvm_unreachable("Invalid size!"); - case 1: OW->Write8 (uint8_t (AF.getValue())); break; - case 2: OW->Write16(uint16_t(AF.getValue())); break; - case 4: OW->Write32(uint32_t(AF.getValue())); break; - case 8: OW->Write64(uint64_t(AF.getValue())); break; + case 1: OW->write8 (uint8_t (AF.getValue())); break; + case 2: OW->write16(uint16_t(AF.getValue())); break; + case 4: OW->write32(uint32_t(AF.getValue())); break; + case 8: OW->write64(uint64_t(AF.getValue())); break; } } break; @@ -619,17 +722,17 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, case MCFragment::FT_Data: ++stats::EmittedDataFragments; - writeFragmentContents(F, OW); + OW->writeBytes(cast(F).getContents()); break; case MCFragment::FT_Relaxable: ++stats::EmittedRelaxableFragments; - writeFragmentContents(F, OW); + OW->writeBytes(cast(F).getContents()); break; case MCFragment::FT_CompactEncodedInst: ++stats::EmittedCompactEncodedInstFragments; - writeFragmentContents(F, OW); + OW->writeBytes(cast(F).getContents()); break; case MCFragment::FT_Fill: { @@ -641,10 +744,10 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) { switch (FF.getValueSize()) { default: llvm_unreachable("Invalid size!"); - case 1: OW->Write8 (uint8_t (FF.getValue())); break; - case 2: OW->Write16(uint16_t(FF.getValue())); break; - case 4: OW->Write32(uint32_t(FF.getValue())); break; - case 8: OW->Write64(uint64_t(FF.getValue())); break; + case 1: OW->write8 (uint8_t (FF.getValue())); break; + case 2: OW->write16(uint16_t(FF.getValue())); break; + case 4: OW->write32(uint32_t(FF.getValue())); break; + case 8: OW->write64(uint64_t(FF.getValue())); break; } } break; @@ -652,7 +755,13 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, case MCFragment::FT_LEB: { const MCLEBFragment &LF = cast(F); - OW->WriteBytes(LF.getContents().str()); + OW->writeBytes(LF.getContents()); + break; + } + + case MCFragment::FT_SafeSEH: { + const MCSafeSEHFragment &SF = cast(F); + OW->write32(SF.getSymbol()->getIndex()); break; } @@ -661,60 +770,66 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout, const MCOrgFragment &OF = cast(F); for (uint64_t i = 0, e = FragmentSize; i != e; ++i) - OW->Write8(uint8_t(OF.getValue())); + OW->write8(uint8_t(OF.getValue())); break; } case MCFragment::FT_Dwarf: { const MCDwarfLineAddrFragment &OF = cast(F); - OW->WriteBytes(OF.getContents().str()); + OW->writeBytes(OF.getContents()); break; } case MCFragment::FT_DwarfFrame: { const MCDwarfCallFrameFragment &CF = cast(F); - OW->WriteBytes(CF.getContents().str()); + OW->writeBytes(CF.getContents()); break; } + case MCFragment::FT_Dummy: + llvm_unreachable("Should not have been added"); } assert(OW->getStream().tell() - Start == FragmentSize && "The stream should advance by fragment size"); } -void MCAssembler::writeSectionData(const MCSectionData *SD, +void MCAssembler::writeSectionData(const MCSection *Sec, const MCAsmLayout &Layout) const { // Ignore virtual sections. - if (SD->getSection().isVirtualSection()) { - assert(Layout.getSectionFileSize(SD) == 0 && "Invalid size for section!"); + if (Sec->isVirtualSection()) { + assert(Layout.getSectionFileSize(Sec) == 0 && "Invalid size for section!"); // Check that contents are only things legal inside a virtual section. - for (MCSectionData::const_iterator it = SD->begin(), - ie = SD->end(); it != ie; ++it) { - switch (it->getKind()) { + for (const MCFragment &F : *Sec) { + switch (F.getKind()) { default: llvm_unreachable("Invalid fragment in virtual section!"); case MCFragment::FT_Data: { // Check that we aren't trying to write a non-zero contents (or fixups) // into a virtual section. This is to support clients which use standard // directives to fill the contents of virtual sections. - const MCDataFragment &DF = cast(*it); + const MCDataFragment &DF = cast(F); assert(DF.fixup_begin() == DF.fixup_end() && "Cannot have fixups in virtual section!"); for (unsigned i = 0, e = DF.getContents().size(); i != e; ++i) - assert(DF.getContents()[i] == 0 && - "Invalid data value for virtual section!"); + if (DF.getContents()[i]) { + if (auto *ELFSec = dyn_cast(Sec)) + report_fatal_error("non-zero initializer found in section '" + + ELFSec->getSectionName() + "'"); + else + report_fatal_error("non-zero initializer found in virtual section"); + } break; } case MCFragment::FT_Align: // Check that we aren't trying to write a non-zero value into a virtual // section. - assert((cast(it)->getValueSize() == 0 || - cast(it)->getValue() == 0) && + assert((cast(F).getValueSize() == 0 || + cast(F).getValue() == 0) && "Invalid align in virtual section!"); break; case MCFragment::FT_Fill: - assert((cast(it)->getValueSize() == 0 || - cast(it)->getValue() == 0) && + assert((cast(F).getValueSize() == 0 || + cast(F).getValue() == 0) && "Invalid fill in virtual section!"); break; } @@ -726,58 +841,55 @@ void MCAssembler::writeSectionData(const MCSectionData *SD, uint64_t Start = getWriter().getStream().tell(); (void)Start; - for (MCSectionData::const_iterator it = SD->begin(), ie = SD->end(); - it != ie; ++it) - writeFragment(*this, Layout, *it); + for (const MCFragment &F : *Sec) + writeFragment(*this, Layout, F); assert(getWriter().getStream().tell() - Start == - Layout.getSectionAddressSize(SD)); + Layout.getSectionAddressSize(Sec)); } - -uint64_t MCAssembler::handleFixup(const MCAsmLayout &Layout, - MCFragment &F, - const MCFixup &Fixup) { +std::pair MCAssembler::handleFixup(const MCAsmLayout &Layout, + MCFragment &F, + const MCFixup &Fixup) { // Evaluate the fixup. MCValue Target; uint64_t FixedValue; + bool IsPCRel = Backend.getFixupKindInfo(Fixup.getKind()).Flags & + MCFixupKindInfo::FKF_IsPCRel; if (!evaluateFixup(Layout, Fixup, &F, Target, FixedValue)) { // The fixup was unresolved, we need a relocation. Inform the object // writer of the relocation, and give it an opportunity to adjust the // fixup value if need be. - getWriter().RecordRelocation(*this, Layout, &F, Fixup, Target, FixedValue); + getWriter().recordRelocation(*this, Layout, &F, Fixup, Target, IsPCRel, + FixedValue); } - return FixedValue; + return std::make_pair(FixedValue, IsPCRel); } -void MCAssembler::Finish() { +void MCAssembler::layout(MCAsmLayout &Layout) { DEBUG_WITH_TYPE("mc-dump", { llvm::errs() << "assembler backend - pre-layout\n--\n"; dump(); }); - // Create the layout object. - MCAsmLayout Layout(*this); - // Create dummy fragments and assign section ordinals. unsigned SectionIndex = 0; - for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) { + for (MCSection &Sec : *this) { // Create dummy fragments to eliminate any empty sections, this simplifies // layout. - if (it->getFragmentList().empty()) - new MCDataFragment(it); + if (Sec.getFragmentList().empty()) + new MCDataFragment(&Sec); - it->setOrdinal(SectionIndex++); + Sec.setOrdinal(SectionIndex++); } // Assign layout order indices to sections and fragments. for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) { - MCSectionData *SD = Layout.getSectionOrder()[i]; - SD->setLayoutOrder(i); + MCSection *Sec = Layout.getSectionOrder()[i]; + Sec->setLayoutOrder(i); unsigned FragmentIndex = 0; - for (MCSectionData::iterator iFrag = SD->begin(), iFragEnd = SD->end(); - iFrag != iFragEnd; ++iFrag) - iFrag->setLayoutOrder(FragmentIndex++); + for (MCFragment &Frag : *Sec) + Frag.setLayoutOrder(FragmentIndex++); } // Layout until everything fits. @@ -795,32 +907,51 @@ void MCAssembler::Finish() { llvm::errs() << "assembler backend - final-layout\n--\n"; dump(); }); - uint64_t StartOffset = OS.tell(); - // Allow the object writer a chance to perform post-layout binding (for // example, to set the index fields in the symbol data). - getWriter().ExecutePostLayoutBinding(*this, Layout); + getWriter().executePostLayoutBinding(*this, Layout); // Evaluate and apply the fixups, generating relocation entries as necessary. - for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) { - for (MCSectionData::iterator it2 = it->begin(), - ie2 = it->end(); it2 != ie2; ++it2) { - MCEncodedFragmentWithFixups *F = - dyn_cast(it2); - if (F) { - for (MCEncodedFragmentWithFixups::fixup_iterator it3 = F->fixup_begin(), - ie3 = F->fixup_end(); it3 != ie3; ++it3) { - MCFixup &Fixup = *it3; - uint64_t FixedValue = handleFixup(Layout, *F, Fixup); - getBackend().applyFixup(Fixup, F->getContents().data(), - F->getContents().size(), FixedValue); - } + for (MCSection &Sec : *this) { + for (MCFragment &Frag : Sec) { + MCEncodedFragment *F = dyn_cast(&Frag); + // Data and relaxable fragments both have fixups. So only process + // those here. + // FIXME: Is there a better way to do this? MCEncodedFragmentWithFixups + // being templated makes this tricky. + if (!F || isa(F)) + continue; + ArrayRef Fixups; + MutableArrayRef Contents; + if (auto *FragWithFixups = dyn_cast(F)) { + Fixups = FragWithFixups->getFixups(); + Contents = FragWithFixups->getContents(); + } else if (auto *FragWithFixups = dyn_cast(F)) { + Fixups = FragWithFixups->getFixups(); + Contents = FragWithFixups->getContents(); + } else + llvm_unreachable("Unknown fragment with fixups!"); + for (const MCFixup &Fixup : Fixups) { + uint64_t FixedValue; + bool IsPCRel; + std::tie(FixedValue, IsPCRel) = handleFixup(Layout, *F, Fixup); + getBackend().applyFixup(Fixup, Contents.data(), + Contents.size(), FixedValue, IsPCRel); } } } +} + +void MCAssembler::Finish() { + // Create the layout object. + MCAsmLayout Layout(*this); + layout(Layout); + + raw_ostream &OS = getWriter().getStream(); + uint64_t StartOffset = OS.tell(); // Write the object file. - getWriter().WriteObject(*this, Layout); + getWriter().writeObject(*this, Layout); stats::ObjectBytes += OS.tell() - StartOffset; } @@ -828,13 +959,11 @@ void MCAssembler::Finish() { bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup, const MCRelaxableFragment *DF, const MCAsmLayout &Layout) const { - // If we cannot resolve the fixup value, it requires relaxation. MCValue Target; uint64_t Value; - if (!evaluateFixup(Layout, Fixup, DF, Target, Value)) - return true; - - return getBackend().fixupNeedsRelaxation(Fixup, Value, DF, Layout); + bool Resolved = evaluateFixup(Layout, Fixup, DF, Target, Value); + return getBackend().fixupNeedsRelaxationAdvanced(Fixup, Resolved, Value, DF, + Layout); } bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F, @@ -845,9 +974,8 @@ bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F, if (!getBackend().mayNeedRelaxation(F->getInst())) return false; - for (MCRelaxableFragment::const_fixup_iterator it = F->fixup_begin(), - ie = F->fixup_end(); it != ie; ++it) - if (fixupNeedsRelaxation(*it, F, Layout)) + for (const MCFixup &Fixup : F->getFixups()) + if (fixupNeedsRelaxation(Fixup, F, Layout)) return true; return false; @@ -875,8 +1003,7 @@ bool MCAssembler::relaxInstruction(MCAsmLayout &Layout, SmallVector Fixups; SmallString<256> Code; raw_svector_ostream VecOS(Code); - getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups, F.getSubtargetInfo()); - VecOS.flush(); + getEmitter().encodeInstruction(Relaxed, VecOS, Fixups, F.getSubtargetInfo()); // Update the fragment. F.setInst(Relaxed); @@ -887,11 +1014,11 @@ bool MCAssembler::relaxInstruction(MCAsmLayout &Layout, } bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) { - int64_t Value = 0; uint64_t OldSize = LF.getContents().size(); - bool IsAbs = LF.getValue().EvaluateAsAbsolute(Value, Layout); - (void)IsAbs; - assert(IsAbs); + int64_t Value; + bool Abs = LF.getValue().evaluateKnownAbsolute(Value, Layout); + if (!Abs) + report_fatal_error("sleb128 and uleb128 expressions must be absolute"); SmallString<8> &Data = LF.getContents(); Data.clear(); raw_svector_ostream OSE(Data); @@ -899,53 +1026,51 @@ bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) { encodeSLEB128(Value, OSE); else encodeULEB128(Value, OSE); - OSE.flush(); return OldSize != LF.getContents().size(); } bool MCAssembler::relaxDwarfLineAddr(MCAsmLayout &Layout, MCDwarfLineAddrFragment &DF) { MCContext &Context = Layout.getAssembler().getContext(); - int64_t AddrDelta = 0; uint64_t OldSize = DF.getContents().size(); - bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout); - (void)IsAbs; - assert(IsAbs); + int64_t AddrDelta; + bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout); + assert(Abs && "We created a line delta with an invalid expression"); + (void) Abs; int64_t LineDelta; LineDelta = DF.getLineDelta(); SmallString<8> &Data = DF.getContents(); Data.clear(); raw_svector_ostream OSE(Data); - MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OSE); - OSE.flush(); + MCDwarfLineAddr::Encode(Context, getDWARFLinetableParams(), LineDelta, + AddrDelta, OSE); return OldSize != Data.size(); } bool MCAssembler::relaxDwarfCallFrameFragment(MCAsmLayout &Layout, MCDwarfCallFrameFragment &DF) { MCContext &Context = Layout.getAssembler().getContext(); - int64_t AddrDelta = 0; uint64_t OldSize = DF.getContents().size(); - bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout); - (void)IsAbs; - assert(IsAbs); + int64_t AddrDelta; + bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout); + assert(Abs && "We created call frame with an invalid expression"); + (void) Abs; SmallString<8> &Data = DF.getContents(); Data.clear(); raw_svector_ostream OSE(Data); MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OSE); - OSE.flush(); return OldSize != Data.size(); } -bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSectionData &SD) { +bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSection &Sec) { // Holds the first fragment which needed relaxing during this layout. It will // remain NULL if none were relaxed. // When a fragment is relaxed, all the fragments following it should get // invalidated because their offset is going to change. - MCFragment *FirstRelaxedFragment = NULL; + MCFragment *FirstRelaxedFragment = nullptr; // Attempt to relax all the fragments in the section. - for (MCSectionData::iterator I = SD.begin(), IE = SD.end(); I != IE; ++I) { + for (MCSection::iterator I = Sec.begin(), IE = Sec.end(); I != IE; ++I) { // Check if this is a fragment that needs relaxation. bool RelaxedFrag = false; switch(I->getKind()) { @@ -984,8 +1109,8 @@ bool MCAssembler::layoutOnce(MCAsmLayout &Layout) { bool WasRelaxed = false; for (iterator it = begin(), ie = end(); it != ie; ++it) { - MCSectionData &SD = *it; - while (layoutSectionOnce(Layout, SD)) + MCSection &Sec = *it; + while (layoutSectionOnce(Layout, Sec)) WasRelaxed = true; } @@ -1028,6 +1153,10 @@ void MCFragment::dump() { case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break; case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break; case MCFragment::FT_LEB: OS << "MCLEBFragment"; break; + case MCFragment::FT_SafeSEH: OS << "MCSafeSEHFragment"; break; + case MCFragment::FT_Dummy: + OS << "MCDummyFragment"; + break; } OS << "getValue() << " Signed:" << LF->isSigned(); break; } + case MCFragment::FT_SafeSEH: { + const MCSafeSEHFragment *F = cast(this); + OS << "\n "; + OS << " Sym:" << F->getSymbol(); + break; } - OS << ">"; -} - -void MCSectionData::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "dump(); + case MCFragment::FT_Dummy: + break; } - OS << "]>"; -} - -void MCSymbolData::dump() { - raw_ostream &OS = llvm::errs(); - - OS << ""; } @@ -1167,21 +1275,11 @@ void MCAssembler::dump() { for (symbol_iterator it = symbol_begin(), ie = symbol_end(); it != ie; ++it) { if (it != symbol_begin()) OS << ",\n "; + OS << "("; it->dump(); + OS << ", Index:" << it->getIndex() << ", "; + OS << ")"; } OS << "]>\n"; } #endif - -// anchors for MC*Fragment vtables -void MCEncodedFragment::anchor() { } -void MCEncodedFragmentWithFixups::anchor() { } -void MCDataFragment::anchor() { } -void MCCompactEncodedInstFragment::anchor() { } -void MCRelaxableFragment::anchor() { } -void MCAlignFragment::anchor() { } -void MCFillFragment::anchor() { } -void MCOrgFragment::anchor() { } -void MCLEBFragment::anchor() { } -void MCDwarfLineAddrFragment::anchor() { } -void MCDwarfCallFrameFragment::anchor() { }