diff options
Diffstat (limited to 'lib/MC/MCAssembler.cpp')
| -rw-r--r-- | lib/MC/MCAssembler.cpp | 794 |
1 files changed, 329 insertions, 465 deletions
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp index f0e1d7fbc21c..999264604224 100644 --- a/lib/MC/MCAssembler.cpp +++ b/lib/MC/MCAssembler.cpp @@ -11,10 +11,13 @@ #include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCAsmLayout.h" #include "llvm/MC/MCCodeEmitter.h" +#include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCObjectWriter.h" +#include "llvm/MC/MCSection.h" #include "llvm/MC/MCSymbol.h" #include "llvm/MC/MCValue.h" +#include "llvm/MC/MCDwarf.h" #include "llvm/ADT/OwningPtr.h" #include "llvm/ADT/Statistic.h" #include "llvm/ADT/StringExtras.h" @@ -36,7 +39,6 @@ STATISTIC(FragmentLayouts, "Number of fragment layouts"); STATISTIC(ObjectBytes, "Number of emitted object file bytes"); STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps"); STATISTIC(RelaxedInstructions, "Number of relaxed instructions"); -STATISTIC(SectionLayouts, "Number of section layouts"); } } @@ -48,131 +50,78 @@ STATISTIC(SectionLayouts, "Number of section layouts"); /* *** */ MCAsmLayout::MCAsmLayout(MCAssembler &Asm) - : Assembler(Asm), LastValidFragment(0) + : 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 (!Asm.getBackend().isVirtualSection(it->getSection())) + if (!it->getSection().isVirtualSection()) SectionOrder.push_back(&*it); for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) - if (Asm.getBackend().isVirtualSection(it->getSection())) + if (it->getSection().isVirtualSection()) SectionOrder.push_back(&*it); } -bool MCAsmLayout::isSectionUpToDate(const MCSectionData *SD) const { - // The first section is always up-to-date. - unsigned Index = SD->getLayoutOrder(); - if (!Index) - return true; - - // Otherwise, sections are always implicitly computed when the preceeding - // fragment is layed out. - const MCSectionData *Prev = getSectionOrder()[Index - 1]; - return isFragmentUpToDate(&(Prev->getFragmentList().back())); -} - bool MCAsmLayout::isFragmentUpToDate(const MCFragment *F) const { - return (LastValidFragment && - F->getLayoutOrder() <= LastValidFragment->getLayoutOrder()); + const MCSectionData &SD = *F->getParent(); + const MCFragment *LastValid = LastValidFragment.lookup(&SD); + if (!LastValid) + return false; + assert(LastValid->getParent() == F->getParent()); + return F->getLayoutOrder() <= LastValid->getLayoutOrder(); } -void MCAsmLayout::UpdateForSlide(MCFragment *F, int SlideAmount) { +void MCAsmLayout::Invalidate(MCFragment *F) { // If this fragment wasn't already up-to-date, we don't need to do anything. if (!isFragmentUpToDate(F)) return; - // Otherwise, reset the last valid fragment to the predecessor of the - // invalidated fragment. - LastValidFragment = F->getPrevNode(); - if (!LastValidFragment) { - unsigned Index = F->getParent()->getLayoutOrder(); - if (Index != 0) { - MCSectionData *Prev = getSectionOrder()[Index - 1]; - LastValidFragment = &(Prev->getFragmentList().back()); - } - } + // Otherwise, reset the last valid fragment to this fragment. + const MCSectionData &SD = *F->getParent(); + LastValidFragment[&SD] = F; } void MCAsmLayout::EnsureValid(const MCFragment *F) const { + MCSectionData &SD = *F->getParent(); + + MCFragment *Cur = LastValidFragment[&SD]; + if (!Cur) + Cur = &*SD.begin(); + else + Cur = Cur->getNextNode(); + // Advance the layout position until the fragment is up-to-date. while (!isFragmentUpToDate(F)) { - // Advance to the next fragment. - MCFragment *Cur = LastValidFragment; - if (Cur) - Cur = Cur->getNextNode(); - if (!Cur) { - unsigned NextIndex = 0; - if (LastValidFragment) - NextIndex = LastValidFragment->getParent()->getLayoutOrder() + 1; - Cur = SectionOrder[NextIndex]->begin(); - } - const_cast<MCAsmLayout*>(this)->LayoutFragment(Cur); + Cur = Cur->getNextNode(); } } -void MCAsmLayout::FragmentReplaced(MCFragment *Src, MCFragment *Dst) { - if (LastValidFragment == Src) - LastValidFragment = Dst; - - Dst->Offset = Src->Offset; - Dst->EffectiveSize = Src->EffectiveSize; -} - -uint64_t MCAsmLayout::getFragmentAddress(const MCFragment *F) const { - assert(F->getParent() && "Missing section()!"); - return getSectionAddress(F->getParent()) + getFragmentOffset(F); -} - -uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const { - EnsureValid(F); - assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!"); - return F->EffectiveSize; -} - uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const { EnsureValid(F); assert(F->Offset != ~UINT64_C(0) && "Address not set!"); return F->Offset; } -uint64_t MCAsmLayout::getSymbolAddress(const MCSymbolData *SD) const { - assert(SD->getFragment() && "Invalid getAddress() on undefined symbol!"); - return getFragmentAddress(SD->getFragment()) + SD->getOffset(); -} - -uint64_t MCAsmLayout::getSectionAddress(const MCSectionData *SD) const { - EnsureValid(SD->begin()); - assert(SD->Address != ~UINT64_C(0) && "Address not set!"); - return SD->Address; +uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const { + assert(SD->getFragment() && "Invalid getOffset() on undefined symbol!"); + return getFragmentOffset(SD->getFragment()) + SD->getOffset(); } uint64_t MCAsmLayout::getSectionAddressSize(const MCSectionData *SD) const { // The size is the last fragment's end offset. const MCFragment &F = SD->getFragmentList().back(); - return getFragmentOffset(&F) + getFragmentEffectiveSize(&F); + return getFragmentOffset(&F) + getAssembler().ComputeFragmentSize(*this, F); } uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const { // Virtual sections have no file size. - if (getAssembler().getBackend().isVirtualSection(SD->getSection())) + if (SD->getSection().isVirtualSection()) return 0; // Otherwise, the file size is the same as the address space size. return getSectionAddressSize(SD); } -uint64_t MCAsmLayout::getSectionSize(const MCSectionData *SD) const { - // The logical size is the address space size minus any tail padding. - uint64_t Size = getSectionAddressSize(SD); - const MCAlignFragment *AF = - dyn_cast<MCAlignFragment>(&(SD->getFragmentList().back())); - if (AF && AF->hasOnlyAlignAddress()) - Size -= getFragmentEffectiveSize(AF); - - return Size; -} - /* *** */ MCFragment::MCFragment() : Kind(FragmentType(~0)) { @@ -182,8 +131,7 @@ MCFragment::~MCFragment() { } MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent) - : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)), - EffectiveSize(~UINT64_C(0)) + : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)) { if (Parent) Parent->getFragmentList().push_back(this); @@ -195,8 +143,8 @@ MCSectionData::MCSectionData() : Section(0) {} MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A) : Section(&_Section), + Ordinal(~UINT32_C(0)), Alignment(1), - Address(~UINT64_C(0)), HasInstructions(false) { if (A) @@ -220,99 +168,17 @@ MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, /* *** */ -MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend, - MCCodeEmitter &_Emitter, raw_ostream &_OS) - : Context(_Context), Backend(_Backend), Emitter(_Emitter), - OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false) +MCAssembler::MCAssembler(MCContext &Context_, TargetAsmBackend &Backend_, + MCCodeEmitter &Emitter_, MCObjectWriter &Writer_, + raw_ostream &OS_) + : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_), + OS(OS_), RelaxAll(false), NoExecStack(false), SubsectionsViaSymbols(false) { } MCAssembler::~MCAssembler() { } -static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm, - const MCFixup &Fixup, - const MCValue Target, - const MCSection *BaseSection) { - // The effective fixup address is - // addr(atom(A)) + offset(A) - // - addr(atom(B)) - offset(B) - // - addr(<base symbol>) + <fixup offset from base symbol> - // and the offsets are not relocatable, so the fixup is fully resolved when - // addr(atom(A)) - addr(atom(B)) - addr(<base symbol>)) == 0. - // - // The simple (Darwin, except on x86_64) way of dealing with this was to - // assume that any reference to a temporary symbol *must* be a temporary - // symbol in the same atom, unless the sections differ. Therefore, any PCrel - // relocation to a temporary symbol (in the same section) is fully - // resolved. This also works in conjunction with absolutized .set, which - // requires the compiler to use .set to absolutize the differences between - // symbols which the compiler knows to be assembly time constants, so we don't - // need to worry about considering symbol differences fully resolved. - - // Non-relative fixups are only resolved if constant. - if (!BaseSection) - return Target.isAbsolute(); - - // Otherwise, relative fixups are only resolved if not a difference and the - // target is a temporary in the same section. - if (Target.isAbsolute() || Target.getSymB()) - return false; - - const MCSymbol *A = &Target.getSymA()->getSymbol(); - if (!A->isTemporary() || !A->isInSection() || - &A->getSection() != BaseSection) - return false; - - return true; -} - -static bool isScatteredFixupFullyResolved(const MCAssembler &Asm, - const MCAsmLayout &Layout, - const MCFixup &Fixup, - const MCValue Target, - const MCSymbolData *BaseSymbol) { - // The effective fixup address is - // addr(atom(A)) + offset(A) - // - addr(atom(B)) - offset(B) - // - addr(BaseSymbol) + <fixup offset from base symbol> - // and the offsets are not relocatable, so the fixup is fully resolved when - // addr(atom(A)) - addr(atom(B)) - addr(BaseSymbol) == 0. - // - // Note that "false" is almost always conservatively correct (it means we emit - // a relocation which is unnecessary), except when it would force us to emit a - // relocation which the target cannot encode. - - const MCSymbolData *A_Base = 0, *B_Base = 0; - if (const MCSymbolRefExpr *A = Target.getSymA()) { - // Modified symbol references cannot be resolved. - if (A->getKind() != MCSymbolRefExpr::VK_None) - return false; - - A_Base = Asm.getAtom(Layout, &Asm.getSymbolData(A->getSymbol())); - if (!A_Base) - return false; - } - - if (const MCSymbolRefExpr *B = Target.getSymB()) { - // Modified symbol references cannot be resolved. - if (B->getKind() != MCSymbolRefExpr::VK_None) - return false; - - B_Base = Asm.getAtom(Layout, &Asm.getSymbolData(B->getSymbol())); - if (!B_Base) - return false; - } - - // If there is no base, A and B have to be the same atom for this fixup to be - // fully resolved. - if (!BaseSymbol) - return A_Base == B_Base; - - // Otherwise, B must be missing and A must be the base. - return !B_Base && BaseSymbol == A_Base; -} - bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const { // Non-temporary labels should always be visible to the linker. if (!Symbol.isTemporary()) @@ -326,8 +192,7 @@ bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const { return getBackend().doesSectionRequireSymbols(Symbol.getSection()); } -const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout, - const MCSymbolData *SD) const { +const MCSymbolData *MCAssembler::getAtom(const MCSymbolData *SD) const { // Linker visible symbols define atoms. if (isSymbolLinkerVisible(SD->getSymbol())) return SD; @@ -351,67 +216,78 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, MCValue &Target, uint64_t &Value) const { ++stats::EvaluateFixup; - if (!Fixup.getValue()->EvaluateAsRelocatable(Target, &Layout)) + if (!Fixup.getValue()->EvaluateAsRelocatable(Target, Layout)) report_fatal_error("expected relocatable expression"); - // FIXME: How do non-scattered symbols work in ELF? I presume the linker - // doesn't support small relocations, but then under what criteria does the - // assembler allow symbol differences? + bool IsPCRel = Backend.getFixupKindInfo( + Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel; + + bool IsResolved; + if (IsPCRel) { + if (Target.getSymB()) { + IsResolved = false; + } else if (!Target.getSymA()) { + IsResolved = false; + } else { + const MCSymbolRefExpr *A = Target.getSymA(); + const MCSymbol &SA = A->getSymbol(); + if (A->getKind() != MCSymbolRefExpr::VK_None || + SA.AliasedSymbol().isUndefined()) { + IsResolved = false; + } else { + const MCSymbolData &DataA = getSymbolData(SA); + IsResolved = + getWriter().IsSymbolRefDifferenceFullyResolvedImpl(*this, DataA, + *DF, false, true); + } + } + } else { + IsResolved = Target.isAbsolute(); + } Value = Target.getConstant(); - bool IsPCRel = Emitter.getFixupKindInfo( - Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel; - bool IsResolved = true; + bool IsThumb = false; if (const MCSymbolRefExpr *A = Target.getSymA()) { - if (A->getSymbol().isDefined()) - Value += Layout.getSymbolAddress(&getSymbolData(A->getSymbol())); - else - IsResolved = false; + const MCSymbol &Sym = A->getSymbol().AliasedSymbol(); + if (Sym.isDefined()) + Value += Layout.getSymbolOffset(&getSymbolData(Sym)); + if (isThumbFunc(&Sym)) + IsThumb = true; } if (const MCSymbolRefExpr *B = Target.getSymB()) { - if (B->getSymbol().isDefined()) - Value -= Layout.getSymbolAddress(&getSymbolData(B->getSymbol())); - else - IsResolved = false; + const MCSymbol &Sym = B->getSymbol().AliasedSymbol(); + if (Sym.isDefined()) + Value -= Layout.getSymbolOffset(&getSymbolData(Sym)); } - // If we are using scattered symbols, determine whether this value is actually - // resolved; scattering may cause atoms to move. - if (IsResolved && getBackend().hasScatteredSymbols()) { - if (getBackend().hasReliableSymbolDifference()) { - // If this is a PCrel relocation, find the base atom (identified by its - // symbol) that the fixup value is relative to. - const MCSymbolData *BaseSymbol = 0; - if (IsPCRel) { - BaseSymbol = DF->getAtom(); - if (!BaseSymbol) - IsResolved = false; - } - if (IsResolved) - IsResolved = isScatteredFixupFullyResolved(*this, Layout, Fixup, Target, - BaseSymbol); - } else { - const MCSection *BaseSection = 0; - if (IsPCRel) - BaseSection = &DF->getParent()->getSection(); + bool ShouldAlignPC = Backend.getFixupKindInfo(Fixup.getKind()).Flags & + MCFixupKindInfo::FKF_IsAlignedDownTo32Bits; + assert((ShouldAlignPC ? IsPCRel : true) && + "FKF_IsAlignedDownTo32Bits is only allowed on PC-relative fixups!"); - IsResolved = isScatteredFixupFullyResolvedSimple(*this, Fixup, Target, - BaseSection); - } + if (IsPCRel) { + uint32_t Offset = Layout.getFragmentOffset(DF) + Fixup.getOffset(); + + // A number of ARM fixups in Thumb mode require that the effective PC + // address be determined as the 32-bit aligned version of the actual offset. + if (ShouldAlignPC) Offset &= ~0x3; + Value -= Offset; } - if (IsPCRel) - Value -= Layout.getFragmentAddress(DF) + Fixup.getOffset(); + // ARM fixups based from a thumb function address need to have the low + // bit set. The actual value is always at least 16-bit aligned, so the + // low bit is normally clear and available for use as an ISA flag for + // interworking. + if (IsThumb) + Value |= 1; return IsResolved; } -uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout, - const MCFragment &F, - uint64_t SectionAddress, - uint64_t FragmentOffset) const { +uint64_t MCAssembler::ComputeFragmentSize(const MCAsmLayout &Layout, + const MCFragment &F) const { switch (F.getKind()) { case MCFragment::FT_Data: return cast<MCDataFragment>(F).getContents().size(); @@ -420,62 +296,48 @@ uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout, case MCFragment::FT_Inst: return cast<MCInstFragment>(F).getInstSize(); + case MCFragment::FT_LEB: + return cast<MCLEBFragment>(F).getContents().size(); + case MCFragment::FT_Align: { const MCAlignFragment &AF = cast<MCAlignFragment>(F); - - assert((!AF.hasOnlyAlignAddress() || !AF.getNextNode()) && - "Invalid OnlyAlignAddress bit, not the last fragment!"); - - uint64_t Size = OffsetToAlignment(SectionAddress + FragmentOffset, - AF.getAlignment()); - - // Honor MaxBytesToEmit. + unsigned Offset = Layout.getFragmentOffset(&AF); + unsigned Size = OffsetToAlignment(Offset, AF.getAlignment()); if (Size > AF.getMaxBytesToEmit()) return 0; - return Size; } case MCFragment::FT_Org: { - const MCOrgFragment &OF = cast<MCOrgFragment>(F); - - // FIXME: We should compute this sooner, we don't want to recurse here, and - // we would like to be more functional. + MCOrgFragment &OF = cast<MCOrgFragment>(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. - int64_t Offset = TargetLocation - FragmentOffset; - if (Offset < 0) + uint64_t FragmentOffset = Layout.getFragmentOffset(&OF); + int64_t Size = TargetLocation - FragmentOffset; + if (Size < 0 || Size >= 0x40000000) report_fatal_error("invalid .org offset '" + Twine(TargetLocation) + - "' (at offset '" + Twine(FragmentOffset) + "'"); - - return Offset; + "' (at offset '" + Twine(FragmentOffset) + "')"); + return Size; } + + case MCFragment::FT_Dwarf: + return cast<MCDwarfLineAddrFragment>(F).getContents().size(); + case MCFragment::FT_DwarfFrame: + return cast<MCDwarfCallFrameFragment>(F).getContents().size(); } assert(0 && "invalid fragment kind"); return 0; } -void MCAsmLayout::LayoutFile() { - // Initialize the first section and set the valid fragment layout point. All - // actual layout computations are done lazily. - LastValidFragment = 0; - if (!getSectionOrder().empty()) - getSectionOrder().front()->Address = 0; -} - void MCAsmLayout::LayoutFragment(MCFragment *F) { MCFragment *Prev = F->getPrevNode(); // We should never try to recompute something which is up-to-date. assert(!isFragmentUpToDate(F) && "Attempt to recompute up-to-date fragment!"); - // We should never try to compute the fragment layout if the section isn't - // up-to-date. - assert(isSectionUpToDate(F->getParent()) && - "Attempt to compute fragment before it's section!"); // We should never try to compute the fragment layout if it's predecessor // isn't up-to-date. assert((!Prev || isFragmentUpToDate(Prev)) && @@ -483,55 +345,26 @@ void MCAsmLayout::LayoutFragment(MCFragment *F) { ++stats::FragmentLayouts; - // Compute the fragment start address. - uint64_t StartAddress = F->getParent()->Address; - uint64_t Address = StartAddress; - if (Prev) - Address += Prev->Offset + Prev->EffectiveSize; - // Compute fragment offset and size. - F->Offset = Address - StartAddress; - F->EffectiveSize = getAssembler().ComputeFragmentSize(*this, *F, StartAddress, - F->Offset); - LastValidFragment = F; - - // If this is the last fragment in a section, update the next section address. - if (!F->getNextNode()) { - unsigned NextIndex = F->getParent()->getLayoutOrder() + 1; - if (NextIndex != getSectionOrder().size()) - LayoutSection(getSectionOrder()[NextIndex]); - } -} - -void MCAsmLayout::LayoutSection(MCSectionData *SD) { - unsigned SectionOrderIndex = SD->getLayoutOrder(); - - ++stats::SectionLayouts; - - // Compute the section start address. - uint64_t StartAddress = 0; - if (SectionOrderIndex) { - MCSectionData *Prev = getSectionOrder()[SectionOrderIndex - 1]; - StartAddress = getSectionAddress(Prev) + getSectionAddressSize(Prev); - } - - // Honor the section alignment requirements. - StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment()); + uint64_t Offset = 0; + if (Prev) + Offset += Prev->Offset + getAssembler().ComputeFragmentSize(*this, *Prev); - // Set the section address. - SD->Address = StartAddress; + F->Offset = Offset; + LastValidFragment[F->getParent()] = F; } /// WriteFragmentData - Write the \arg F data to the output file. static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCFragment &F, MCObjectWriter *OW) { + const MCFragment &F) { + MCObjectWriter *OW = &Asm.getWriter(); uint64_t Start = OW->getStream().tell(); (void) Start; ++stats::EmittedFragments; // FIXME: Embed in fragments instead? - uint64_t FragmentSize = Layout.getFragmentEffectiveSize(&F); + uint64_t FragmentSize = Asm.ComputeFragmentSize(Layout, F); switch (F.getKind()) { case MCFragment::FT_Align: { MCAlignFragment &AF = cast<MCAlignFragment>(F); @@ -598,9 +431,17 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, break; } - case MCFragment::FT_Inst: - llvm_unreachable("unexpected inst fragment after lowering"); + case MCFragment::FT_Inst: { + MCInstFragment &IF = cast<MCInstFragment>(F); + OW->WriteBytes(StringRef(IF.getCode().begin(), IF.getCode().size())); + break; + } + + case MCFragment::FT_LEB: { + MCLEBFragment &LF = cast<MCLEBFragment>(F); + OW->WriteBytes(LF.getContents().str()); break; + } case MCFragment::FT_Org: { MCOrgFragment &OF = cast<MCOrgFragment>(F); @@ -610,16 +451,26 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, break; } + + case MCFragment::FT_Dwarf: { + const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F); + OW->WriteBytes(OF.getContents().str()); + break; + } + case MCFragment::FT_DwarfFrame: { + const MCDwarfCallFrameFragment &CF = cast<MCDwarfCallFrameFragment>(F); + OW->WriteBytes(CF.getContents().str()); + break; + } } assert(OW->getStream().tell() - Start == FragmentSize); } void MCAssembler::WriteSectionData(const MCSectionData *SD, - const MCAsmLayout &Layout, - MCObjectWriter *OW) const { + const MCAsmLayout &Layout) const { // Ignore virtual sections. - if (getBackend().isVirtualSection(SD->getSection())) { + if (SD->getSection().isVirtualSection()) { assert(Layout.getSectionFileSize(SD) == 0 && "Invalid size for section!"); // Check that contents are only things legal inside a virtual section. @@ -657,51 +508,34 @@ void MCAssembler::WriteSectionData(const MCSectionData *SD, return; } - uint64_t Start = OW->getStream().tell(); + uint64_t Start = getWriter().getStream().tell(); (void) Start; for (MCSectionData::const_iterator it = SD->begin(), ie = SD->end(); it != ie; ++it) - WriteFragmentData(*this, Layout, *it, OW); + WriteFragmentData(*this, Layout, *it); - assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(SD)); + assert(getWriter().getStream().tell() - Start == + Layout.getSectionAddressSize(SD)); } -void MCAssembler::AddSectionToTheEnd(MCSectionData &SD, MCAsmLayout &Layout) { - // Create dummy fragments and assign section ordinals. - unsigned SectionIndex = 0; - for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) - SectionIndex++; - - SD.setOrdinal(SectionIndex); - - // Assign layout order indices to sections and fragments. - unsigned FragmentIndex = 0; - unsigned i = 0; - for (unsigned e = Layout.getSectionOrder().size(); i != e; ++i) { - MCSectionData *SD = Layout.getSectionOrder()[i]; - for (MCSectionData::iterator it2 = SD->begin(), - ie2 = SD->end(); it2 != ie2; ++it2) - FragmentIndex++; - } +uint64_t MCAssembler::HandleFixup(const MCAsmLayout &Layout, + MCFragment &F, + const MCFixup &Fixup) { + // Evaluate the fixup. + MCValue Target; + uint64_t FixedValue; + 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); + } + return FixedValue; + } - SD.setLayoutOrder(i); - for (MCSectionData::iterator it2 = SD.begin(), - ie2 = SD.end(); it2 != ie2; ++it2) { - it2->setLayoutOrder(FragmentIndex++); - } - Layout.getSectionOrder().push_back(&SD); - - Layout.LayoutSection(&SD); - - // Layout until everything fits. - while (LayoutOnce(Layout)) - continue; - -} - -void MCAssembler::Finish(MCObjectWriter *Writer) { +void MCAssembler::Finish() { DEBUG_WITH_TYPE("mc-dump", { llvm::errs() << "assembler backend - pre-layout\n--\n"; dump(); }); @@ -709,47 +543,23 @@ void MCAssembler::Finish(MCObjectWriter *Writer) { // Create the layout object. MCAsmLayout Layout(*this); - // Insert additional align fragments for concrete sections to explicitly pad - // the previous section to match their alignment requirements. This is for - // 'gas' compatibility, it shouldn't strictly be necessary. - // - // FIXME: This may be Mach-O specific. - for (unsigned i = 1, e = Layout.getSectionOrder().size(); i < e; ++i) { - MCSectionData *SD = Layout.getSectionOrder()[i]; - - // Ignore sections without alignment requirements. - unsigned Align = SD->getAlignment(); - if (Align <= 1) - continue; - - // Ignore virtual sections, they don't cause file size modifications. - if (getBackend().isVirtualSection(SD->getSection())) - continue; - - // Otherwise, create a new align fragment at the end of the previous - // section. - MCAlignFragment *AF = new MCAlignFragment(Align, 0, 1, Align, - Layout.getSectionOrder()[i - 1]); - AF->setOnlyAlignAddress(true); - } - // Create dummy fragments and assign section ordinals. unsigned SectionIndex = 0; for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) { // Create dummy fragments to eliminate any empty sections, this simplifies // layout. if (it->getFragmentList().empty()) - new MCFillFragment(0, 1, 0, it); + new MCDataFragment(it); it->setOrdinal(SectionIndex++); } // Assign layout order indices to sections and fragments. - unsigned FragmentIndex = 0; for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) { MCSectionData *SD = Layout.getSectionOrder()[i]; SD->setLayoutOrder(i); + unsigned FragmentIndex = 0; for (MCSectionData::iterator it2 = SD->begin(), ie2 = SD->end(); it2 != ie2; ++it2) it2->setLayoutOrder(FragmentIndex++); @@ -772,48 +582,39 @@ void MCAssembler::Finish(MCObjectWriter *Writer) { uint64_t StartOffset = OS.tell(); - llvm::OwningPtr<MCObjectWriter> OwnWriter(0); - if (Writer == 0) { - //no custom Writer_ : create the default one life-managed by OwningPtr - OwnWriter.reset(getBackend().createObjectWriter(OS)); - Writer = OwnWriter.get(); - if (!Writer) - report_fatal_error("unable to create object writer!"); - } - // Allow the object writer a chance to perform post-layout binding (for // example, to set the index fields in the symbol data). - Writer->ExecutePostLayoutBinding(*this); + 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) { MCDataFragment *DF = dyn_cast<MCDataFragment>(it2); - if (!DF) - continue; - - for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(), - ie3 = DF->fixup_end(); it3 != ie3; ++it3) { - MCFixup &Fixup = *it3; - - // Evaluate the fixup. - MCValue Target; - uint64_t FixedValue; - if (!EvaluateFixup(Layout, Fixup, DF, 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. - Writer->RecordRelocation(*this, Layout, DF, Fixup, Target,FixedValue); + if (DF) { + for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(), + ie3 = DF->fixup_end(); it3 != ie3; ++it3) { + MCFixup &Fixup = *it3; + uint64_t FixedValue = HandleFixup(Layout, *DF, Fixup); + getBackend().ApplyFixup(Fixup, DF->getContents().data(), + DF->getContents().size(), FixedValue); + } + } + MCInstFragment *IF = dyn_cast<MCInstFragment>(it2); + if (IF) { + for (MCInstFragment::fixup_iterator it3 = IF->fixup_begin(), + ie3 = IF->fixup_end(); it3 != ie3; ++it3) { + MCFixup &Fixup = *it3; + uint64_t FixedValue = HandleFixup(Layout, *IF, Fixup); + getBackend().ApplyFixup(Fixup, IF->getCode().data(), + IF->getCode().size(), FixedValue); } - - getBackend().ApplyFixup(Fixup, *DF, FixedValue); } } } // Write the object file. - Writer->WriteObject(*this, Layout); + getWriter().WriteObject(*this, Layout); stats::ObjectBytes += OS.tell() - StartOffset; } @@ -852,100 +653,144 @@ bool MCAssembler::FragmentNeedsRelaxation(const MCInstFragment *IF, return false; } -bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { - ++stats::RelaxationSteps; +bool MCAssembler::RelaxInstruction(MCAsmLayout &Layout, + MCInstFragment &IF) { + if (!FragmentNeedsRelaxation(&IF, Layout)) + return false; - // Layout the sections in order. - Layout.LayoutFile(); + ++stats::RelaxedInstructions; + // FIXME-PERF: We could immediately lower out instructions if we can tell + // they are fully resolved, to avoid retesting on later passes. + + // Relax the fragment. + + MCInst Relaxed; + getBackend().RelaxInstruction(IF.getInst(), Relaxed); + + // Encode the new instruction. + // + // FIXME-PERF: If it matters, we could let the target do this. It can + // probably do so more efficiently in many cases. + SmallVector<MCFixup, 4> Fixups; + SmallString<256> Code; + raw_svector_ostream VecOS(Code); + getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups); + VecOS.flush(); + + // Update the instruction fragment. + IF.setInst(Relaxed); + IF.getCode() = Code; + IF.getFixups().clear(); + // FIXME: Eliminate copy. + for (unsigned i = 0, e = Fixups.size(); i != e; ++i) + IF.getFixups().push_back(Fixups[i]); + + return true; +} + +bool MCAssembler::RelaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) { + int64_t Value = 0; + uint64_t OldSize = LF.getContents().size(); + LF.getValue().EvaluateAsAbsolute(Value, Layout); + SmallString<8> &Data = LF.getContents(); + Data.clear(); + raw_svector_ostream OSE(Data); + if (LF.isSigned()) + MCObjectWriter::EncodeSLEB128(Value, OSE); + else + MCObjectWriter::EncodeULEB128(Value, OSE); + OSE.flush(); + return OldSize != LF.getContents().size(); +} + +bool MCAssembler::RelaxDwarfLineAddr(MCAsmLayout &Layout, + MCDwarfLineAddrFragment &DF) { + int64_t AddrDelta = 0; + uint64_t OldSize = DF.getContents().size(); + bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout); + (void)IsAbs; + assert(IsAbs); + int64_t LineDelta; + LineDelta = DF.getLineDelta(); + SmallString<8> &Data = DF.getContents(); + Data.clear(); + raw_svector_ostream OSE(Data); + MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OSE); + OSE.flush(); + return OldSize != Data.size(); +} + +bool MCAssembler::RelaxDwarfCallFrameFragment(MCAsmLayout &Layout, + MCDwarfCallFrameFragment &DF) { + int64_t AddrDelta = 0; + uint64_t OldSize = DF.getContents().size(); + bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout); + (void)IsAbs; + assert(IsAbs); + SmallString<8> &Data = DF.getContents(); + Data.clear(); + raw_svector_ostream OSE(Data); + MCDwarfFrameEmitter::EncodeAdvanceLoc(AddrDelta, OSE); + OSE.flush(); + return OldSize != Data.size(); +} + +bool MCAssembler::LayoutSectionOnce(MCAsmLayout &Layout, + MCSectionData &SD) { + MCFragment *FirstInvalidFragment = NULL; // Scan for fragments that need relaxation. + for (MCSectionData::iterator it2 = SD.begin(), + ie2 = SD.end(); it2 != ie2; ++it2) { + // Check if this is an fragment that needs relaxation. + bool relaxedFrag = false; + switch(it2->getKind()) { + default: + break; + case MCFragment::FT_Inst: + relaxedFrag = RelaxInstruction(Layout, *cast<MCInstFragment>(it2)); + break; + case MCFragment::FT_Dwarf: + relaxedFrag = RelaxDwarfLineAddr(Layout, + *cast<MCDwarfLineAddrFragment>(it2)); + break; + case MCFragment::FT_DwarfFrame: + relaxedFrag = + RelaxDwarfCallFrameFragment(Layout, + *cast<MCDwarfCallFrameFragment>(it2)); + break; + case MCFragment::FT_LEB: + relaxedFrag = RelaxLEB(Layout, *cast<MCLEBFragment>(it2)); + break; + } + // Update the layout, and remember that we relaxed. + if (relaxedFrag && !FirstInvalidFragment) + FirstInvalidFragment = it2; + } + if (FirstInvalidFragment) { + Layout.Invalidate(FirstInvalidFragment); + return true; + } + return false; +} + +bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { + ++stats::RelaxationSteps; + bool WasRelaxed = false; for (iterator it = begin(), ie = end(); it != ie; ++it) { MCSectionData &SD = *it; - - for (MCSectionData::iterator it2 = SD.begin(), - ie2 = SD.end(); it2 != ie2; ++it2) { - // Check if this is an instruction fragment that needs relaxation. - MCInstFragment *IF = dyn_cast<MCInstFragment>(it2); - if (!IF || !FragmentNeedsRelaxation(IF, Layout)) - continue; - - ++stats::RelaxedInstructions; - - // FIXME-PERF: We could immediately lower out instructions if we can tell - // they are fully resolved, to avoid retesting on later passes. - - // Relax the fragment. - - MCInst Relaxed; - getBackend().RelaxInstruction(IF->getInst(), Relaxed); - - // Encode the new instruction. - // - // FIXME-PERF: If it matters, we could let the target do this. It can - // probably do so more efficiently in many cases. - SmallVector<MCFixup, 4> Fixups; - SmallString<256> Code; - raw_svector_ostream VecOS(Code); - getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups); - VecOS.flush(); - - // Update the instruction fragment. - int SlideAmount = Code.size() - IF->getInstSize(); - IF->setInst(Relaxed); - IF->getCode() = Code; - IF->getFixups().clear(); - // FIXME: Eliminate copy. - for (unsigned i = 0, e = Fixups.size(); i != e; ++i) - IF->getFixups().push_back(Fixups[i]); - - // Update the layout, and remember that we relaxed. - Layout.UpdateForSlide(IF, SlideAmount); + while(LayoutSectionOnce(Layout, SD)) WasRelaxed = true; - } } return WasRelaxed; } void MCAssembler::FinishLayout(MCAsmLayout &Layout) { - // Lower out any instruction fragments, to simplify the fixup application and - // output. - // - // FIXME-PERF: We don't have to do this, but the assumption is that it is - // cheap (we will mostly end up eliminating fragments and appending on to data - // fragments), so the extra complexity downstream isn't worth it. Evaluate - // this assumption. - for (iterator it = begin(), ie = end(); it != ie; ++it) { - MCSectionData &SD = *it; - - for (MCSectionData::iterator it2 = SD.begin(), - ie2 = SD.end(); it2 != ie2; ++it2) { - MCInstFragment *IF = dyn_cast<MCInstFragment>(it2); - if (!IF) - continue; - - // Create a new data fragment for the instruction. - // - // FIXME-PERF: Reuse previous data fragment if possible. - MCDataFragment *DF = new MCDataFragment(); - SD.getFragmentList().insert(it2, DF); - - // Update the data fragments layout data. - DF->setParent(IF->getParent()); - DF->setAtom(IF->getAtom()); - DF->setLayoutOrder(IF->getLayoutOrder()); - Layout.FragmentReplaced(IF, DF); - - // Copy in the data and the fixups. - DF->getContents().append(IF->getCode().begin(), IF->getCode().end()); - for (unsigned i = 0, e = IF->getFixups().size(); i != e; ++i) - DF->getFixups().push_back(IF->getFixups()[i]); - - // Delete the instruction fragment and update the iterator. - SD.getFragmentList().erase(IF); - it2 = DF; - } + // The layout is done. Mark every fragment as valid. + for (unsigned int i = 0, n = Layout.getSectionOrder().size(); i != n; ++i) { + Layout.getFragmentOffset(&*Layout.getSectionOrder()[i]->rbegin()); } } @@ -972,18 +817,19 @@ void MCFragment::dump() { case MCFragment::FT_Fill: OS << "MCFillFragment"; break; case MCFragment::FT_Inst: OS << "MCInstFragment"; break; case MCFragment::FT_Org: OS << "MCOrgFragment"; break; + case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break; + case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break; + case MCFragment::FT_LEB: OS << "MCLEBFragment"; break; } OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder - << " Offset:" << Offset << " EffectiveSize:" << EffectiveSize << ">"; + << " Offset:" << Offset << ">"; switch (getKind()) { case MCFragment::FT_Align: { const MCAlignFragment *AF = cast<MCAlignFragment>(this); if (AF->hasEmitNops()) OS << " (emit nops)"; - if (AF->hasOnlyAlignAddress()) - OS << " (only align section)"; OS << "\n "; OS << " Alignment:" << AF->getAlignment() << " Value:" << AF->getValue() << " ValueSize:" << AF->getValueSize() @@ -1032,6 +878,25 @@ void MCFragment::dump() { OS << " Offset:" << OF->getOffset() << " Value:" << OF->getValue(); break; } + case MCFragment::FT_Dwarf: { + const MCDwarfLineAddrFragment *OF = cast<MCDwarfLineAddrFragment>(this); + OS << "\n "; + OS << " AddrDelta:" << OF->getAddrDelta() + << " LineDelta:" << OF->getLineDelta(); + break; + } + case MCFragment::FT_DwarfFrame: { + const MCDwarfCallFrameFragment *CF = cast<MCDwarfCallFrameFragment>(this); + OS << "\n "; + OS << " AddrDelta:" << CF->getAddrDelta(); + break; + } + case MCFragment::FT_LEB: { + const MCLEBFragment *LF = cast<MCLEBFragment>(this); + OS << "\n "; + OS << " Value:" << LF->getValue() << " Signed:" << LF->isSigned(); + break; + } } OS << ">"; } @@ -1040,8 +905,7 @@ void MCSectionData::dump() { raw_ostream &OS = llvm::errs(); OS << "<MCSectionData"; - OS << " Alignment:" << getAlignment() << " Address:" << Address - << " Fragments:[\n "; + OS << " Alignment:" << getAlignment() << " Fragments:[\n "; for (iterator it = begin(), ie = end(); it != ie; ++it) { if (it != begin()) OS << ",\n "; it->dump(); |