X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCAssembler.cpp;h=143d284897f3d93494db12fa2cac5dfd7a0f05ae;hb=0eba49c22e81ffb6aa9290684f383e7352f00574;hp=459488bfe15bedde043e18541447e34ae77cfbac;hpb=937e781f4942494ca379736978945c7b6c3d4dea;p=oota-llvm.git diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp index 459488bfe15..143d284897f 100644 --- a/lib/MC/MCAssembler.cpp +++ b/lib/MC/MCAssembler.cpp @@ -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" @@ -28,7 +29,6 @@ #include "llvm/Support/LEB128.h" #include "llvm/Support/TargetRegistry.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/MC/MCSectionELF.h" #include using namespace llvm; @@ -68,20 +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(); } @@ -92,16 +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(); @@ -120,41 +118,35 @@ uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const { } // Simple getSymbolOffset helper for the non-varibale case. -static bool getLabelOffset(const MCAsmLayout &Layout, const MCSymbolData &SD, +static bool getLabelOffset(const MCAsmLayout &Layout, const MCSymbol &S, bool ReportError, uint64_t &Val) { - if (!SD.getFragment()) { + if (!S.getFragment()) { if (ReportError) report_fatal_error("unable to evaluate offset to undefined symbol '" + - SD.getSymbol().getName() + "'"); + S.getName() + "'"); return false; } - Val = Layout.getFragmentOffset(SD.getFragment()) + SD.getOffset(); + Val = Layout.getFragmentOffset(S.getFragment()) + S.getOffset(); return true; } -static bool getSymbolOffsetImpl(const MCAsmLayout &Layout, - const MCSymbolData *SD, bool ReportError, - uint64_t &Val) { - const MCSymbol &S = SD->getSymbol(); - +static bool getSymbolOffsetImpl(const MCAsmLayout &Layout, const MCSymbol &S, + bool ReportError, uint64_t &Val) { if (!S.isVariable()) - return getLabelOffset(Layout, *SD, ReportError, Val); + return getLabelOffset(Layout, S, ReportError, Val); // If SD is a variable, evaluate it. MCValue Target; - if (!S.getVariableValue()->EvaluateAsValue(Target, &Layout, nullptr)) + if (!S.getVariableValue()->evaluateAsValue(Target, Layout)) report_fatal_error("unable to evaluate offset for variable '" + S.getName() + "'"); uint64_t Offset = Target.getConstant(); - const MCAssembler &Asm = Layout.getAssembler(); - const MCSymbolRefExpr *A = Target.getSymA(); if (A) { uint64_t ValA; - if (!getLabelOffset(Layout, Asm.getSymbolData(A->getSymbol()), ReportError, - ValA)) + if (!getLabelOffset(Layout, A->getSymbol(), ReportError, ValA)) return false; Offset += ValA; } @@ -162,8 +154,7 @@ static bool getSymbolOffsetImpl(const MCAsmLayout &Layout, const MCSymbolRefExpr *B = Target.getSymB(); if (B) { uint64_t ValB; - if (!getLabelOffset(Layout, Asm.getSymbolData(B->getSymbol()), ReportError, - ValB)) + if (!getLabelOffset(Layout, B->getSymbol(), ReportError, ValB)) return false; Offset -= ValB; } @@ -172,13 +163,13 @@ static bool getSymbolOffsetImpl(const MCAsmLayout &Layout, return true; } -bool MCAsmLayout::getSymbolOffset(const MCSymbolData *SD, uint64_t &Val) const { - return getSymbolOffsetImpl(*this, SD, false, Val); +bool MCAsmLayout::getSymbolOffset(const MCSymbol &S, uint64_t &Val) const { + return getSymbolOffsetImpl(*this, S, false, Val); } -uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const { +uint64_t MCAsmLayout::getSymbolOffset(const MCSymbol &S) const { uint64_t Val; - getSymbolOffsetImpl(*this, SD, true, Val); + getSymbolOffsetImpl(*this, S, true, Val); return Val; } @@ -188,12 +179,12 @@ const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const { const MCExpr *Expr = Symbol.getVariableValue(); MCValue Value; - if (!Expr->EvaluateAsValue(Value, this, nullptr)) + if (!Expr->evaluateAsValue(Value, *this)) llvm_unreachable("Invalid Expression"); const MCSymbolRefExpr *RefB = Value.getSymB(); if (RefB) - Assembler.getContext().FatalError( + Assembler.getContext().reportFatalError( SMLoc(), Twine("symbol '") + RefB->getSymbol().getName() + "' could not be evaluated in a subtraction expression"); @@ -201,26 +192,36 @@ const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const { if (!A) return nullptr; - return &A->getSymbol(); + 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"); + } + + 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"); @@ -253,7 +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; @@ -261,115 +262,76 @@ uint64_t MCAsmLayout::computeBundlePadding(const MCFragment *F, /* *** */ -MCFragment::MCFragment() : Kind(FragmentType(~0)) { +void ilist_node_traits::deleteNode(MCFragment *V) { + V->destroy(); } -MCFragment::~MCFragment() { +MCFragment::MCFragment() : Kind(FragmentType(~0)), HasInstructions(false), + AlignToBundleEnd(false), BundlePadding(0) { } -MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent) - : Kind(_Kind), Parent(_Parent), Atom(nullptr), Offset(~UINT64_C(0)) -{ - if (Parent) - Parent->getFragmentList().push_back(this); -} - -/* *** */ - -MCEncodedFragment::~MCEncodedFragment() { -} +MCFragment::~MCFragment() { } -/* *** */ - -MCEncodedFragmentWithFixups::~MCEncodedFragmentWithFixups() { -} - -/* *** */ - -MCSectionData::MCSectionData() : Section(nullptr) {} - -MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A) - : Section(&_Section), - Ordinal(~UINT32_C(0)), - Alignment(1), - BundleLockState(NotBundleLocked), - BundleLockNestingDepth(0), - BundleGroupBeforeFirstInst(false), - HasInstructions(false) -{ - if (A) - A->getSectionList().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 *)nullptr)); - 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); - } - return IP; +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); } -void MCSectionData::setBundleLockState(BundleLockStateType NewState) { - if (NewState == NotBundleLocked) { - if (BundleLockNestingDepth == 0) { - report_fatal_error("Mismatched bundle_lock/unlock directives"); - } - if (--BundleLockNestingDepth == 0) { - BundleLockState = NotBundleLocked; - } +void MCFragment::destroy() { + // First check if we are the sentinal. + if (Kind == FragmentType(~0)) { + delete this; return; } - // If any of the directives is an align_to_end directive, the whole nested - // group is align_to_end. So don't downgrade from align_to_end to just locked. - if (BundleLockState != BundleLockedAlignToEnd) { - BundleLockState = NewState; + 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; } - ++BundleLockNestingDepth; -} - -/* *** */ - -MCSymbolData::MCSymbolData() : Symbol(nullptr) {} - -MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, - uint64_t _Offset, MCAssembler *A) - : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset), - SymbolSize(nullptr), CommonAlign(-1U), Flags(0), Index(0) { - if (A) - A->getSymbolList().push_back(this); } /* *** */ MCAssembler::MCAssembler(MCContext &Context_, MCAsmBackend &Backend_, - MCCodeEmitter &Emitter_, MCObjectWriter &Writer_, - raw_ostream &OS_) + MCCodeEmitter &Emitter_, MCObjectWriter &Writer_) : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_), - OS(OS_), BundleAlignSize(0), RelaxAll(false), - SubsectionsViaSymbols(false), ELFHeaderEFlags(0) { + BundleAlignSize(0), RelaxAll(false), SubsectionsViaSymbols(false), + ELFHeaderEFlags(0) { VersionMinInfo.Major = 0; // Major version == 0 for "none specified" } @@ -379,8 +341,6 @@ MCAssembler::~MCAssembler() { void MCAssembler::reset() { Sections.clear(); Symbols.clear(); - SectionMap.clear(); - SymbolMap.clear(); IndirectSymbols.clear(); DataRegions.clear(); LinkerOptions.clear(); @@ -400,6 +360,14 @@ void MCAssembler::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; @@ -434,39 +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()) + if (!S.isInSection()) return nullptr; // Non-linker visible symbols in sections which can't be atomized have no // defining atom. if (!getContext().getAsmInfo()->isSectionAtomizableBySymbols( - SD->getFragment()->getParent()->getSection())) + *S.getFragment()->getParent())) return nullptr; // Otherwise, return the atom for the containing fragment. - return SD->getFragment()->getAtom(); -} - -// Try to fully compute Expr to an absolute value and if that fails produce -// a relocatable expr. -// FIXME: Should this be the behavior of EvaluateAsRelocatable itself? -static bool evaluate(const MCExpr &Expr, const MCAsmLayout &Layout, - const MCFixup &Fixup, MCValue &Target) { - if (Expr.EvaluateAsValue(Target, &Layout, &Fixup)) { - if (Target.isAbsolute()) - return true; - } - return Expr.EvaluateAsRelocatable(Target, &Layout, &Fixup); + return S.getFragment()->getAtom(); } bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout, @@ -474,12 +432,12 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout, MCValue &Target, uint64_t &Value) const { ++stats::evaluateFixup; - // FIXME: This code has some duplication with RecordRelocation. We should + // 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 (!evaluate(*Expr, Layout, Fixup, Target)) - getContext().FatalError(Fixup.getLoc(), "expected relocatable expression"); + if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup)) + getContext().reportFatalError(Fixup.getLoc(), "expected relocatable expression"); bool IsPCRel = Backend.getFixupKindInfo( Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel; @@ -493,14 +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 { @@ -510,14 +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); } @@ -547,15 +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); @@ -574,7 +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. @@ -590,6 +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"); @@ -630,15 +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)); @@ -646,31 +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 @@ -679,16 +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. @@ -729,10 +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; @@ -740,17 +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: { @@ -762,10 +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; @@ -773,7 +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; } @@ -782,48 +770,49 @@ 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) if (DF.getContents()[i]) { - if (auto *ELFSec = dyn_cast(&SD->getSection())) + if (auto *ELFSec = dyn_cast(Sec)) report_fatal_error("non-zero initializer found in section '" + ELFSec->getSectionName() + "'"); else @@ -834,13 +823,13 @@ void MCAssembler::writeSectionData(const MCSectionData *SD, 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; } @@ -852,12 +841,11 @@ 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)); } std::pair MCAssembler::handleFixup(const MCAsmLayout &Layout, @@ -872,40 +860,36 @@ std::pair MCAssembler::handleFixup(const MCAsmLayout &Layout, // 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, IsPCRel, + getWriter().recordRelocation(*this, Layout, &F, Fixup, Target, IsPCRel, 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. @@ -923,34 +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; - bool IsPCRel; - std::tie(FixedValue, IsPCRel) = handleFixup(Layout, *F, Fixup); - getBackend().applyFixup(Fixup, F->getContents().data(), - F->getContents().size(), FixedValue, IsPCRel); - } + 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; } @@ -958,13 +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, @@ -975,9 +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; @@ -1005,8 +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); @@ -1018,7 +1015,10 @@ bool MCAssembler::relaxInstruction(MCAsmLayout &Layout, bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) { uint64_t OldSize = LF.getContents().size(); - int64_t Value = LF.getValue().evaluateKnownAbsolute(Layout); + 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); @@ -1026,7 +1026,6 @@ bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) { encodeSLEB128(Value, OSE); else encodeULEB128(Value, OSE); - OSE.flush(); return OldSize != LF.getContents().size(); } @@ -1034,14 +1033,17 @@ bool MCAssembler::relaxDwarfLineAddr(MCAsmLayout &Layout, MCDwarfLineAddrFragment &DF) { MCContext &Context = Layout.getAssembler().getContext(); uint64_t OldSize = DF.getContents().size(); - int64_t AddrDelta = DF.getAddrDelta().evaluateKnownAbsolute(Layout); + 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(); } @@ -1049,16 +1051,18 @@ bool MCAssembler::relaxDwarfCallFrameFragment(MCAsmLayout &Layout, MCDwarfCallFrameFragment &DF) { MCContext &Context = Layout.getAssembler().getContext(); uint64_t OldSize = DF.getContents().size(); - int64_t AddrDelta = DF.getAddrDelta().evaluateKnownAbsolute(Layout); + 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 @@ -1066,7 +1070,7 @@ bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSectionData &SD) { 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()) { @@ -1105,8 +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; } @@ -1149,6 +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() const { - raw_ostream &OS = llvm::errs(); - - OS << ""; } @@ -1290,21 +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() { }