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Diffstat (limited to 'contrib/llvm/lib/MC/MCObjectStreamer.cpp')
| -rw-r--r-- | contrib/llvm/lib/MC/MCObjectStreamer.cpp | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/MCObjectStreamer.cpp b/contrib/llvm/lib/MC/MCObjectStreamer.cpp new file mode 100644 index 0000000..a721b59 --- /dev/null +++ b/contrib/llvm/lib/MC/MCObjectStreamer.cpp @@ -0,0 +1,383 @@ +//===- lib/MC/MCObjectStreamer.cpp - Object File MCStreamer Interface -----===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/MC/MCObjectStreamer.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/MC/MCAsmBackend.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCCodeEmitter.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCDwarf.h" +#include "llvm/MC/MCExpr.h" +#include "llvm/MC/MCObjectWriter.h" +#include "llvm/MC/MCSection.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Support/ErrorHandling.h" +using namespace llvm; + +MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, + raw_ostream &OS, MCCodeEmitter *Emitter_) + : MCStreamer(Context), + Assembler(new MCAssembler(Context, TAB, *Emitter_, + *TAB.createObjectWriter(OS), OS)), + CurSectionData(nullptr), EmitEHFrame(true), EmitDebugFrame(false) {} + +MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, + raw_ostream &OS, MCCodeEmitter *Emitter_, + MCAssembler *_Assembler) + : MCStreamer(Context), Assembler(_Assembler), CurSectionData(nullptr), + EmitEHFrame(true), EmitDebugFrame(false) {} + +MCObjectStreamer::~MCObjectStreamer() { + delete &Assembler->getBackend(); + delete &Assembler->getEmitter(); + delete &Assembler->getWriter(); + delete Assembler; +} + +void MCObjectStreamer::reset() { + if (Assembler) + Assembler->reset(); + CurSectionData = nullptr; + CurInsertionPoint = MCSectionData::iterator(); + EmitEHFrame = true; + EmitDebugFrame = false; + MCStreamer::reset(); +} + +void MCObjectStreamer::EmitFrames(MCAsmBackend *MAB) { + if (!getNumFrameInfos()) + return; + + if (EmitEHFrame) + MCDwarfFrameEmitter::Emit(*this, MAB, true); + + if (EmitDebugFrame) + MCDwarfFrameEmitter::Emit(*this, MAB, false); +} + +MCFragment *MCObjectStreamer::getCurrentFragment() const { + assert(getCurrentSectionData() && "No current section!"); + + if (CurInsertionPoint != getCurrentSectionData()->getFragmentList().begin()) + return std::prev(CurInsertionPoint); + + return nullptr; +} + +MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() const { + MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment()); + // When bundling is enabled, we don't want to add data to a fragment that + // already has instructions (see MCELFStreamer::EmitInstToData for details) + if (!F || (Assembler->isBundlingEnabled() && F->hasInstructions())) { + F = new MCDataFragment(); + insert(F); + } + return F; +} + +void MCObjectStreamer::visitUsedSymbol(const MCSymbol &Sym) { + Assembler->getOrCreateSymbolData(Sym); +} + +void MCObjectStreamer::EmitCFISections(bool EH, bool Debug) { + MCStreamer::EmitCFISections(EH, Debug); + EmitEHFrame = EH; + EmitDebugFrame = Debug; +} + +void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size, + const SMLoc &Loc) { + MCStreamer::EmitValueImpl(Value, Size, Loc); + MCDataFragment *DF = getOrCreateDataFragment(); + + MCLineEntry::Make(this, getCurrentSection().first); + + // Avoid fixups when possible. + int64_t AbsValue; + if (Value->EvaluateAsAbsolute(AbsValue, getAssembler())) { + EmitIntValue(AbsValue, Size); + return; + } + DF->getFixups().push_back( + MCFixup::Create(DF->getContents().size(), Value, + MCFixup::getKindForSize(Size, false), Loc)); + DF->getContents().resize(DF->getContents().size() + Size, 0); +} + +void MCObjectStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) { + // We need to create a local symbol to avoid relocations. + Frame.Begin = getContext().CreateTempSymbol(); + EmitLabel(Frame.Begin); +} + +void MCObjectStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) { + Frame.End = getContext().CreateTempSymbol(); + EmitLabel(Frame.End); +} + +void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) { + MCStreamer::EmitLabel(Symbol); + + MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); + + // FIXME: This is wasteful, we don't necessarily need to create a data + // fragment. Instead, we should mark the symbol as pointing into the data + // fragment if it exists, otherwise we should just queue the label and set its + // fragment pointer when we emit the next fragment. + MCDataFragment *F = getOrCreateDataFragment(); + assert(!SD.getFragment() && "Unexpected fragment on symbol data!"); + SD.setFragment(F); + SD.setOffset(F->getContents().size()); +} + +void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value) { + int64_t IntValue; + if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) { + EmitULEB128IntValue(IntValue); + return; + } + Value = ForceExpAbs(Value); + insert(new MCLEBFragment(*Value, false)); +} + +void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value) { + int64_t IntValue; + if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) { + EmitSLEB128IntValue(IntValue); + return; + } + Value = ForceExpAbs(Value); + insert(new MCLEBFragment(*Value, true)); +} + +void MCObjectStreamer::EmitWeakReference(MCSymbol *Alias, + const MCSymbol *Symbol) { + report_fatal_error("This file format doesn't support weak aliases."); +} + +void MCObjectStreamer::ChangeSection(const MCSection *Section, + const MCExpr *Subsection) { + assert(Section && "Cannot switch to a null section!"); + + CurSectionData = &getAssembler().getOrCreateSectionData(*Section); + + int64_t IntSubsection = 0; + if (Subsection && + !Subsection->EvaluateAsAbsolute(IntSubsection, getAssembler())) + report_fatal_error("Cannot evaluate subsection number"); + if (IntSubsection < 0 || IntSubsection > 8192) + report_fatal_error("Subsection number out of range"); + CurInsertionPoint = + CurSectionData->getSubsectionInsertionPoint(unsigned(IntSubsection)); +} + +void MCObjectStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) { + getAssembler().getOrCreateSymbolData(*Symbol); + MCStreamer::EmitAssignment(Symbol, Value); +} + +void MCObjectStreamer::EmitInstruction(const MCInst &Inst, + const MCSubtargetInfo &STI) { + MCStreamer::EmitInstruction(Inst, STI); + + MCSectionData *SD = getCurrentSectionData(); + SD->setHasInstructions(true); + + // Now that a machine instruction has been assembled into this section, make + // a line entry for any .loc directive that has been seen. + MCLineEntry::Make(this, getCurrentSection().first); + + // If this instruction doesn't need relaxation, just emit it as data. + MCAssembler &Assembler = getAssembler(); + if (!Assembler.getBackend().mayNeedRelaxation(Inst)) { + EmitInstToData(Inst, STI); + return; + } + + // Otherwise, relax and emit it as data if either: + // - The RelaxAll flag was passed + // - Bundling is enabled and this instruction is inside a bundle-locked + // group. We want to emit all such instructions into the same data + // fragment. + if (Assembler.getRelaxAll() || + (Assembler.isBundlingEnabled() && SD->isBundleLocked())) { + MCInst Relaxed; + getAssembler().getBackend().relaxInstruction(Inst, Relaxed); + while (getAssembler().getBackend().mayNeedRelaxation(Relaxed)) + getAssembler().getBackend().relaxInstruction(Relaxed, Relaxed); + EmitInstToData(Relaxed, STI); + return; + } + + // Otherwise emit to a separate fragment. + EmitInstToFragment(Inst, STI); +} + +void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst, + const MCSubtargetInfo &STI) { + // Always create a new, separate fragment here, because its size can change + // during relaxation. + MCRelaxableFragment *IF = new MCRelaxableFragment(Inst, STI); + insert(IF); + + SmallString<128> Code; + raw_svector_ostream VecOS(Code); + getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, IF->getFixups(), + STI); + VecOS.flush(); + IF->getContents().append(Code.begin(), Code.end()); +} + +#ifndef NDEBUG +static const char *const BundlingNotImplementedMsg = + "Aligned bundling is not implemented for this object format"; +#endif + +void MCObjectStreamer::EmitBundleAlignMode(unsigned AlignPow2) { + llvm_unreachable(BundlingNotImplementedMsg); +} + +void MCObjectStreamer::EmitBundleLock(bool AlignToEnd) { + llvm_unreachable(BundlingNotImplementedMsg); +} + +void MCObjectStreamer::EmitBundleUnlock() { + llvm_unreachable(BundlingNotImplementedMsg); +} + +void MCObjectStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line, + unsigned Column, unsigned Flags, + unsigned Isa, + unsigned Discriminator, + StringRef FileName) { + // In case we see two .loc directives in a row, make sure the + // first one gets a line entry. + MCLineEntry::Make(this, getCurrentSection().first); + + this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags, + Isa, Discriminator, FileName); +} + +void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta, + const MCSymbol *LastLabel, + const MCSymbol *Label, + unsigned PointerSize) { + if (!LastLabel) { + EmitDwarfSetLineAddr(LineDelta, Label, PointerSize); + return; + } + const MCExpr *AddrDelta = BuildSymbolDiff(getContext(), Label, LastLabel); + int64_t Res; + if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) { + MCDwarfLineAddr::Emit(this, LineDelta, Res); + return; + } + AddrDelta = ForceExpAbs(AddrDelta); + insert(new MCDwarfLineAddrFragment(LineDelta, *AddrDelta)); +} + +void MCObjectStreamer::EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, + const MCSymbol *Label) { + const MCExpr *AddrDelta = BuildSymbolDiff(getContext(), Label, LastLabel); + int64_t Res; + if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) { + MCDwarfFrameEmitter::EmitAdvanceLoc(*this, Res); + return; + } + AddrDelta = ForceExpAbs(AddrDelta); + insert(new MCDwarfCallFrameFragment(*AddrDelta)); +} + +void MCObjectStreamer::EmitBytes(StringRef Data) { + MCLineEntry::Make(this, getCurrentSection().first); + getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end()); +} + +void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment, + int64_t Value, + unsigned ValueSize, + unsigned MaxBytesToEmit) { + if (MaxBytesToEmit == 0) + MaxBytesToEmit = ByteAlignment; + insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit)); + + // Update the maximum alignment on the current section if necessary. + if (ByteAlignment > getCurrentSectionData()->getAlignment()) + getCurrentSectionData()->setAlignment(ByteAlignment); +} + +void MCObjectStreamer::EmitCodeAlignment(unsigned ByteAlignment, + unsigned MaxBytesToEmit) { + EmitValueToAlignment(ByteAlignment, 0, 1, MaxBytesToEmit); + cast<MCAlignFragment>(getCurrentFragment())->setEmitNops(true); +} + +bool MCObjectStreamer::EmitValueToOffset(const MCExpr *Offset, + unsigned char Value) { + int64_t Res; + if (Offset->EvaluateAsAbsolute(Res, getAssembler())) { + insert(new MCOrgFragment(*Offset, Value)); + return false; + } + + MCSymbol *CurrentPos = getContext().CreateTempSymbol(); + EmitLabel(CurrentPos); + MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None; + const MCExpr *Ref = + MCSymbolRefExpr::Create(CurrentPos, Variant, getContext()); + const MCExpr *Delta = + MCBinaryExpr::Create(MCBinaryExpr::Sub, Offset, Ref, getContext()); + + if (!Delta->EvaluateAsAbsolute(Res, getAssembler())) + return true; + EmitFill(Res, Value); + return false; +} + +// Associate GPRel32 fixup with data and resize data area +void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) { + MCDataFragment *DF = getOrCreateDataFragment(); + + DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(), + Value, FK_GPRel_4)); + DF->getContents().resize(DF->getContents().size() + 4, 0); +} + +// Associate GPRel32 fixup with data and resize data area +void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) { + MCDataFragment *DF = getOrCreateDataFragment(); + + DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(), + Value, FK_GPRel_4)); + DF->getContents().resize(DF->getContents().size() + 8, 0); +} + +void MCObjectStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) { + // FIXME: A MCFillFragment would be more memory efficient but MCExpr has + // problems evaluating expressions across multiple fragments. + getOrCreateDataFragment()->getContents().append(NumBytes, FillValue); +} + +void MCObjectStreamer::EmitZeros(uint64_t NumBytes) { + unsigned ItemSize = getCurrentSection().first->isVirtualSection() ? 0 : 1; + insert(new MCFillFragment(0, ItemSize, NumBytes)); +} + +void MCObjectStreamer::FinishImpl() { + // If we are generating dwarf for assembly source files dump out the sections. + if (getContext().getGenDwarfForAssembly()) + MCGenDwarfInfo::Emit(this); + + // Dump out the dwarf file & directory tables and line tables. + MCDwarfLineTable::Emit(this); + + getAssembler().Finish(); +} |
