X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCAssembler.cpp;h=f0e1d7fbc21c5ebc0a2a455c7a31d5dc1edb758f;hb=316abba6b7b744a2f6795087eab25943a1247a41;hp=fbda26b4ce8a0db2bbf2d45be7fa842dd0d5997b;hpb=e73d49eda2cb4fc30b52c4a241acf69c8af98302;p=oota-llvm.git diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp index fbda26b4ce8..f0e1d7fbc21 100644 --- a/lib/MC/MCAssembler.cpp +++ b/lib/MC/MCAssembler.cpp @@ -47,7 +47,9 @@ STATISTIC(SectionLayouts, "Number of section layouts"); /* *** */ -MCAsmLayout::MCAsmLayout(MCAssembler &Asm) : Assembler(Asm) { +MCAsmLayout::MCAsmLayout(MCAssembler &Asm) + : Assembler(Asm), LastValidFragment(0) + { // 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())) @@ -57,20 +59,64 @@ MCAsmLayout::MCAsmLayout(MCAssembler &Asm) : Assembler(Asm) { 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()); +} + void MCAsmLayout::UpdateForSlide(MCFragment *F, int SlideAmount) { - // We shouldn't have to do anything special to support negative slides, and it - // is a perfectly valid thing to do as long as other parts of the system can - // guarantee convergence. - assert(SlideAmount >= 0 && "Negative slides not yet supported"); + // If this fragment wasn't already up-to-date, we don't need to do anything. + if (!isFragmentUpToDate(F)) + return; - // Update the layout by simply recomputing the layout for the entire - // file. This is trivially correct, but very slow. - // - // FIXME-PERF: This is O(N^2), but will be eliminated once we get smarter. + // 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()); + } + } +} - // Layout the sections in order. - for (unsigned i = 0, e = getSectionOrder().size(); i != e; ++i) - getAssembler().LayoutSection(*this, i); +void MCAsmLayout::EnsureValid(const MCFragment *F) const { + // 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(this)->LayoutFragment(Cur); + } +} + +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 { @@ -79,51 +125,52 @@ uint64_t MCAsmLayout::getFragmentAddress(const MCFragment *F) const { } uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const { + EnsureValid(F); assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!"); return F->EffectiveSize; } -void MCAsmLayout::setFragmentEffectiveSize(MCFragment *F, uint64_t Value) { - F->EffectiveSize = Value; -} - uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const { + EnsureValid(F); assert(F->Offset != ~UINT64_C(0) && "Address not set!"); return F->Offset; } -void MCAsmLayout::setFragmentOffset(MCFragment *F, uint64_t Value) { - F->Offset = Value; -} - 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; } -void MCAsmLayout::setSectionAddress(MCSectionData *SD, uint64_t Value) { - SD->Address = Value; -} - -uint64_t MCAsmLayout::getSectionSize(const MCSectionData *SD) const { - assert(SD->Size != ~UINT64_C(0) && "File size not set!"); - return SD->Size; -} -void MCAsmLayout::setSectionSize(MCSectionData *SD, uint64_t Value) { - SD->Size = Value; +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); } uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const { - assert(SD->FileSize != ~UINT64_C(0) && "File size not set!"); - return SD->FileSize; + // Virtual sections have no file size. + if (getAssembler().getBackend().isVirtualSection(SD->getSection())) + return 0; + + // Otherwise, the file size is the same as the address space size. + return getSectionAddressSize(SD); } -void MCAsmLayout::setSectionFileSize(MCSectionData *SD, uint64_t Value) { - SD->FileSize = Value; + +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(&(SD->getFragmentList().back())); + if (AF && AF->hasOnlyAlignAddress()) + Size -= getFragmentEffectiveSize(AF); + + return Size; } /* *** */ @@ -131,16 +178,17 @@ void MCAsmLayout::setSectionFileSize(MCSectionData *SD, uint64_t Value) { MCFragment::MCFragment() : Kind(FragmentType(~0)) { } +MCFragment::~MCFragment() { +} + MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent) - : Kind(_Kind), Parent(_Parent), Atom(0), EffectiveSize(~UINT64_C(0)) + : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)), + EffectiveSize(~UINT64_C(0)) { if (Parent) Parent->getFragmentList().push_back(this); } -MCFragment::~MCFragment() { -} - /* *** */ MCSectionData::MCSectionData() : Section(0) {} @@ -149,8 +197,6 @@ MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A) : Section(&_Section), Alignment(1), Address(~UINT64_C(0)), - Size(~UINT64_C(0)), - FileSize(~UINT64_C(0)), HasInstructions(false) { if (A) @@ -165,7 +211,8 @@ MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, uint64_t _Offset, MCAssembler *A) : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset), IsExternal(false), IsPrivateExtern(false), - CommonSize(0), CommonAlign(0), Flags(0), Index(0) + CommonSize(0), SymbolSize(0), CommonAlign(0), + Flags(0), Index(0) { if (A) A->getSymbolList().push_back(this); @@ -184,7 +231,7 @@ MCAssembler::~MCAssembler() { } static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm, - const MCAsmFixup &Fixup, + const MCFixup &Fixup, const MCValue Target, const MCSection *BaseSection) { // The effective fixup address is @@ -222,7 +269,7 @@ static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm, static bool isScatteredFixupFullyResolved(const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCAsmFixup &Fixup, + const MCFixup &Fixup, const MCValue Target, const MCSymbolData *BaseSymbol) { // The effective fixup address is @@ -266,24 +313,23 @@ static bool isScatteredFixupFullyResolved(const MCAssembler &Asm, return !B_Base && BaseSymbol == A_Base; } -bool MCAssembler::isSymbolLinkerVisible(const MCSymbolData *SD) const { +bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const { // Non-temporary labels should always be visible to the linker. - if (!SD->getSymbol().isTemporary()) + if (!Symbol.isTemporary()) return true; // Absolute temporary labels are never visible. - if (!SD->getFragment()) + if (!Symbol.isInSection()) return false; // Otherwise, check if the section requires symbols even for temporary labels. - return getBackend().doesSectionRequireSymbols( - SD->getFragment()->getParent()->getSection()); + return getBackend().doesSectionRequireSymbols(Symbol.getSection()); } const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout, const MCSymbolData *SD) const { // Linker visible symbols define atoms. - if (isSymbolLinkerVisible(SD)) + if (isSymbolLinkerVisible(SD->getSymbol())) return SD; // Absolute and undefined symbols have no defining atom. @@ -301,11 +347,11 @@ const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout, } bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, - const MCAsmFixup &Fixup, const MCFragment *DF, + const MCFixup &Fixup, const MCFragment *DF, MCValue &Target, uint64_t &Value) const { ++stats::EvaluateFixup; - if (!Fixup.Value->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 @@ -314,8 +360,8 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, Value = Target.getConstant(); - bool IsPCRel = - Emitter.getFixupKindInfo(Fixup.Kind).Flags & MCFixupKindInfo::FKF_IsPCRel; + bool IsPCRel = Emitter.getFixupKindInfo( + Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel; bool IsResolved = true; if (const MCSymbolRefExpr *A = Target.getSymA()) { if (A->getSymbol().isDefined()) @@ -357,55 +403,44 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, } if (IsPCRel) - Value -= Layout.getFragmentAddress(DF) + Fixup.Offset; + Value -= Layout.getFragmentAddress(DF) + Fixup.getOffset(); return IsResolved; } -void MCAssembler::LayoutFragment(MCAsmLayout &Layout, MCFragment &F) { - uint64_t StartAddress = Layout.getSectionAddress(F.getParent()); - - // Get the fragment start address. - uint64_t Address = StartAddress; - MCSectionData::iterator it = &F; - if (MCFragment *Prev = F.getPrevNode()) - Address = (StartAddress + Layout.getFragmentOffset(Prev) + - Layout.getFragmentEffectiveSize(Prev)); - - ++stats::FragmentLayouts; - - uint64_t FragmentOffset = Address - StartAddress; - Layout.setFragmentOffset(&F, FragmentOffset); - - // Evaluate fragment size. - uint64_t EffectiveSize = 0; +uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout, + const MCFragment &F, + uint64_t SectionAddress, + uint64_t FragmentOffset) const { switch (F.getKind()) { + case MCFragment::FT_Data: + return cast(F).getContents().size(); + case MCFragment::FT_Fill: + return cast(F).getSize(); + case MCFragment::FT_Inst: + return cast(F).getInstSize(); + case MCFragment::FT_Align: { - MCAlignFragment &AF = cast(F); + const MCAlignFragment &AF = cast(F); - EffectiveSize = OffsetToAlignment(Address, AF.getAlignment()); - if (EffectiveSize > AF.getMaxBytesToEmit()) - EffectiveSize = 0; - break; - } + assert((!AF.hasOnlyAlignAddress() || !AF.getNextNode()) && + "Invalid OnlyAlignAddress bit, not the last fragment!"); - case MCFragment::FT_Data: - EffectiveSize = cast(F).getContents().size(); - break; + uint64_t Size = OffsetToAlignment(SectionAddress + FragmentOffset, + AF.getAlignment()); - case MCFragment::FT_Fill: { - MCFillFragment &FF = cast(F); - EffectiveSize = FF.getValueSize() * FF.getCount(); - break; - } + // Honor MaxBytesToEmit. + if (Size > AF.getMaxBytesToEmit()) + return 0; - case MCFragment::FT_Inst: - EffectiveSize = cast(F).getInstSize(); - break; + return Size; + } case MCFragment::FT_Org: { - MCOrgFragment &OF = cast(F); + const MCOrgFragment &OF = cast(F); + // FIXME: We should compute this sooner, we don't want to recurse here, and + // we would like to be more functional. int64_t TargetLocation; if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout)) report_fatal_error("expected assembly-time absolute expression"); @@ -416,62 +451,75 @@ void MCAssembler::LayoutFragment(MCAsmLayout &Layout, MCFragment &F) { report_fatal_error("invalid .org offset '" + Twine(TargetLocation) + "' (at offset '" + Twine(FragmentOffset) + "'"); - EffectiveSize = Offset; - break; - } - - case MCFragment::FT_ZeroFill: { - EffectiveSize = cast(F).getSize(); - break; + return Offset; } } - Layout.setFragmentEffectiveSize(&F, EffectiveSize); + assert(0 && "invalid fragment kind"); + return 0; } -void MCAssembler::LayoutSection(MCAsmLayout &Layout, - unsigned SectionOrderIndex) { - MCSectionData &SD = *Layout.getSectionOrder()[SectionOrderIndex]; - bool IsVirtual = getBackend().isVirtualSection(SD.getSection()); +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; +} - ++stats::SectionLayouts; +void MCAsmLayout::LayoutFragment(MCFragment *F) { + MCFragment *Prev = F->getPrevNode(); - // Get the section start address. - uint64_t StartAddress = 0; - if (SectionOrderIndex) { - MCSectionData *Prev = Layout.getSectionOrder()[SectionOrderIndex - 1]; - StartAddress = Layout.getSectionAddress(Prev) + Layout.getSectionSize(Prev); - } - - // Align this section if necessary by adding padding bytes to the previous - // section. It is safe to adjust this out-of-band, because no symbol or - // fragment is allowed to point past the end of the section at any time. - if (uint64_t Pad = OffsetToAlignment(StartAddress, SD.getAlignment())) { - // Unless this section is virtual (where we are allowed to adjust the offset - // freely), the padding goes in the previous section. - if (!IsVirtual) { - assert(SectionOrderIndex && "Invalid initial section address!"); - MCSectionData *Prev = Layout.getSectionOrder()[SectionOrderIndex - 1]; - Layout.setSectionFileSize(Prev, Layout.getSectionFileSize(Prev) + Pad); - } + // 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)) && + "Attempt to compute fragment before it's predecessor!"); + + ++stats::FragmentLayouts; - StartAddress += Pad; + // 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]); } +} - // Set the aligned section address. - Layout.setSectionAddress(&SD, StartAddress); +void MCAsmLayout::LayoutSection(MCSectionData *SD) { + unsigned SectionOrderIndex = SD->getLayoutOrder(); - for (MCSectionData::iterator it = SD.begin(), ie = SD.end(); it != ie; ++it) - LayoutFragment(Layout, *it); + ++stats::SectionLayouts; - // Set the section sizes. - uint64_t Size = 0; - if (!SD.getFragmentList().empty()) { - MCFragment *F = &SD.getFragmentList().back(); - Size = Layout.getFragmentOffset(F) + Layout.getFragmentEffectiveSize(F); + // Compute the section start address. + uint64_t StartAddress = 0; + if (SectionOrderIndex) { + MCSectionData *Prev = getSectionOrder()[SectionOrderIndex - 1]; + StartAddress = getSectionAddress(Prev) + getSectionAddressSize(Prev); } - Layout.setSectionSize(&SD, Size); - Layout.setSectionFileSize(&SD, IsVirtual ? 0 : Size); + + // Honor the section alignment requirements. + StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment()); + + // Set the section address. + SD->Address = StartAddress; } /// WriteFragmentData - Write the \arg F data to the output file. @@ -504,7 +552,7 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, // the Count bytes. Then if that did not fill any bytes or there are any // bytes left to fill use the the Value and ValueSize to fill the rest. // If we are aligning with nops, ask that target to emit the right data. - if (AF.getEmitNops()) { + if (AF.hasEmitNops()) { if (!Asm.getBackend().WriteNopData(Count, OW)) report_fatal_error("unable to write nop sequence of " + Twine(Count) + " bytes"); @@ -534,7 +582,10 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, case MCFragment::FT_Fill: { MCFillFragment &FF = cast(F); - for (uint64_t i = 0, e = FF.getCount(); i != e; ++i) { + + assert(FF.getValueSize() && "Invalid virtual align in concrete fragment!"); + + for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) { switch (FF.getValueSize()) { default: assert(0 && "Invalid size!"); @@ -559,11 +610,6 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, break; } - - case MCFragment::FT_ZeroFill: { - assert(0 && "Invalid zero fill fragment in concrete section!"); - break; - } } assert(OW->getStream().tell() - Start == FragmentSize); @@ -572,12 +618,42 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, void MCAssembler::WriteSectionData(const MCSectionData *SD, const MCAsmLayout &Layout, MCObjectWriter *OW) const { - uint64_t SectionSize = Layout.getSectionSize(SD); - uint64_t SectionFileSize = Layout.getSectionFileSize(SD); - // Ignore virtual sections. if (getBackend().isVirtualSection(SD->getSection())) { - assert(SectionFileSize == 0 && "Invalid size for section!"); + assert(Layout.getSectionFileSize(SD) == 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()) { + default: + assert(0 && "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. + MCDataFragment &DF = cast(*it); + 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!"); + 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() || + !cast(it)->getValue()) && + "Invalid align in virtual section!"); + break; + case MCFragment::FT_Fill: + assert(!cast(it)->getValueSize() && + "Invalid fill in virtual section!"); + break; + } + } + return; } @@ -588,32 +664,98 @@ void MCAssembler::WriteSectionData(const MCSectionData *SD, ie = SD->end(); it != ie; ++it) WriteFragmentData(*this, Layout, *it, OW); - // Add section padding. - assert(SectionFileSize >= SectionSize && "Invalid section sizes!"); - OW->WriteZeros(SectionFileSize - SectionSize); + assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(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++; + } + + 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; - assert(OW->getStream().tell() - Start == SectionFileSize); } -void MCAssembler::Finish() { +void MCAssembler::Finish(MCObjectWriter *Writer) { DEBUG_WITH_TYPE("mc-dump", { llvm::errs() << "assembler backend - pre-layout\n--\n"; dump(); }); - // Assign section and fragment ordinals, all subsequent backend code is - // responsible for updating these in place. + // 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; - unsigned FragmentIndex = 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); + it->setOrdinal(SectionIndex++); + } - for (MCSectionData::iterator it2 = it->begin(), - ie2 = it->end(); it2 != ie2; ++it2) - it2->setOrdinal(FragmentIndex++); + // 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); + + for (MCSectionData::iterator it2 = SD->begin(), + ie2 = SD->end(); it2 != ie2; ++it2) + it2->setLayoutOrder(FragmentIndex++); } // Layout until everything fits. - MCAsmLayout Layout(*this); while (LayoutOnce(Layout)) continue; @@ -629,9 +771,15 @@ void MCAssembler::Finish() { dump(); }); uint64_t StartOffset = OS.tell(); - llvm::OwningPtr Writer(getBackend().createObjectWriter(OS)); - if (!Writer) - report_fatal_error("unable to create object writer!"); + + llvm::OwningPtr 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). @@ -647,7 +795,7 @@ void MCAssembler::Finish() { for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(), ie3 = DF->fixup_end(); it3 != ie3; ++it3) { - MCAsmFixup &Fixup = *it3; + MCFixup &Fixup = *it3; // Evaluate the fixup. MCValue Target; @@ -666,12 +814,11 @@ void MCAssembler::Finish() { // Write the object file. Writer->WriteObject(*this, Layout); - OS.flush(); stats::ObjectBytes += OS.tell() - StartOffset; } -bool MCAssembler::FixupNeedsRelaxation(const MCAsmFixup &Fixup, +bool MCAssembler::FixupNeedsRelaxation(const MCFixup &Fixup, const MCFragment *DF, const MCAsmLayout &Layout) const { if (getRelaxAll()) @@ -694,7 +841,7 @@ bool MCAssembler::FragmentNeedsRelaxation(const MCInstFragment *IF, // If this inst doesn't ever need relaxation, ignore it. This occurs when we // are intentionally pushing out inst fragments, or because we relaxed a // previous instruction to one that doesn't need relaxation. - if (!getBackend().MayNeedRelaxation(IF->getInst(), IF->getFixups())) + if (!getBackend().MayNeedRelaxation(IF->getInst())) return false; for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(), @@ -709,8 +856,7 @@ bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { ++stats::RelaxationSteps; // Layout the sections in order. - for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) - LayoutSection(Layout, i); + Layout.LayoutFile(); // Scan for fragments that need relaxation. bool WasRelaxed = false; @@ -732,7 +878,7 @@ bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { // Relax the fragment. MCInst Relaxed; - getBackend().RelaxInstruction(IF, Relaxed); + getBackend().RelaxInstruction(IF->getInst(), Relaxed); // Encode the new instruction. // @@ -749,17 +895,12 @@ bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { IF->setInst(Relaxed); IF->getCode() = Code; IF->getFixups().clear(); - for (unsigned i = 0, e = Fixups.size(); i != e; ++i) { - MCFixup &F = Fixups[i]; - IF->getFixups().push_back(MCAsmFixup(F.getOffset(), *F.getValue(), - F.getKind())); - } + // 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. If we are relaxing - // everything, we can skip this step since nothing will depend on updating - // the values. - if (!getRelaxAll()) - Layout.UpdateForSlide(IF, SlideAmount); + // Update the layout, and remember that we relaxed. + Layout.UpdateForSlide(IF, SlideAmount); WasRelaxed = true; } } @@ -791,13 +932,10 @@ void MCAssembler::FinishLayout(MCAsmLayout &Layout) { SD.getFragmentList().insert(it2, DF); // Update the data fragments layout data. - // - // FIXME: Add MCAsmLayout utility for this. DF->setParent(IF->getParent()); DF->setAtom(IF->getAtom()); - DF->setOrdinal(IF->getOrdinal()); - Layout.setFragmentOffset(DF, Layout.getFragmentOffset(IF)); - Layout.setFragmentEffectiveSize(DF, Layout.getFragmentEffectiveSize(IF)); + DF->setLayoutOrder(IF->getLayoutOrder()); + Layout.FragmentReplaced(IF, DF); // Copy in the data and the fixups. DF->getContents().append(IF->getCode().begin(), IF->getCode().end()); @@ -815,9 +953,10 @@ void MCAssembler::FinishLayout(MCAsmLayout &Layout) { namespace llvm { -raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) { - OS << ""; +raw_ostream &operator<<(raw_ostream &OS, const MCFixup &AF) { + OS << ""; return OS; } @@ -826,94 +965,82 @@ raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) { void MCFragment::dump() { raw_ostream &OS = llvm::errs(); - OS << ""; -} - -void MCAlignFragment::dump() { - raw_ostream &OS = llvm::errs(); + OS << "<"; + switch (getKind()) { + case MCFragment::FT_Align: OS << "MCAlignFragment"; break; + case MCFragment::FT_Data: OS << "MCDataFragment"; break; + case MCFragment::FT_Fill: OS << "MCFillFragment"; break; + case MCFragment::FT_Inst: OS << "MCInstFragment"; break; + case MCFragment::FT_Org: OS << "MCOrgFragment"; break; + } - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Alignment:" << getAlignment() - << " Value:" << getValue() << " ValueSize:" << getValueSize() - << " MaxBytesToEmit:" << getMaxBytesToEmit() << ">"; -} + OS << ""; -void MCDataFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Contents:["; - for (unsigned i = 0, e = getContents().size(); i != e; ++i) { - if (i) OS << ","; - OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF); - } - OS << "] (" << getContents().size() << " bytes)"; - - if (!getFixups().empty()) { - OS << ",\n "; - OS << " Fixups:["; - for (fixup_iterator it = fixup_begin(), ie = fixup_end(); it != ie; ++it) { - if (it != fixup_begin()) OS << ",\n "; - OS << *it; + switch (getKind()) { + case MCFragment::FT_Align: { + const MCAlignFragment *AF = cast(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() + << " MaxBytesToEmit:" << AF->getMaxBytesToEmit() << ">"; + break; + } + case MCFragment::FT_Data: { + const MCDataFragment *DF = cast(this); + OS << "\n "; + OS << " Contents:["; + const SmallVectorImpl &Contents = DF->getContents(); + for (unsigned i = 0, e = Contents.size(); i != e; ++i) { + if (i) OS << ","; + OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF); } - OS << "]"; + OS << "] (" << Contents.size() << " bytes)"; + + if (!DF->getFixups().empty()) { + OS << ",\n "; + OS << " Fixups:["; + for (MCDataFragment::const_fixup_iterator it = DF->fixup_begin(), + ie = DF->fixup_end(); it != ie; ++it) { + if (it != DF->fixup_begin()) OS << ",\n "; + OS << *it; + } + OS << "]"; + } + break; + } + case MCFragment::FT_Fill: { + const MCFillFragment *FF = cast(this); + OS << " Value:" << FF->getValue() << " ValueSize:" << FF->getValueSize() + << " Size:" << FF->getSize(); + break; + } + case MCFragment::FT_Inst: { + const MCInstFragment *IF = cast(this); + OS << "\n "; + OS << " Inst:"; + IF->getInst().dump_pretty(OS); + break; + } + case MCFragment::FT_Org: { + const MCOrgFragment *OF = cast(this); + OS << "\n "; + OS << " Offset:" << OF->getOffset() << " Value:" << OF->getValue(); + break; + } } - - OS << ">"; -} - -void MCFillFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Value:" << getValue() << " ValueSize:" << getValueSize() - << " Count:" << getCount() << ">"; -} - -void MCInstFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Inst:"; - getInst().dump_pretty(OS); OS << ">"; } -void MCOrgFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Offset:" << getOffset() << " Value:" << getValue() << ">"; -} - -void MCZeroFillFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Size:" << getSize() << ">"; -} - void MCSectionData::dump() { raw_ostream &OS = llvm::errs(); OS << "