| //===- 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/MCAsmInfo.h" |
| #include "llvm/MC/MCObjectStreamer.h" |
| |
| #include "llvm/Support/ErrorHandling.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/MCSymbol.h" |
| #include "llvm/MC/MCAsmBackend.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(0) |
| { |
| } |
| |
| MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, |
| raw_ostream &OS, MCCodeEmitter *Emitter_, |
| MCAssembler *_Assembler) |
| : MCStreamer(Context), Assembler(_Assembler), CurSectionData(0) |
| { |
| } |
| |
| MCObjectStreamer::~MCObjectStreamer() { |
| delete &Assembler->getBackend(); |
| delete &Assembler->getEmitter(); |
| delete &Assembler->getWriter(); |
| delete Assembler; |
| } |
| |
| MCFragment *MCObjectStreamer::getCurrentFragment() const { |
| assert(getCurrentSectionData() && "No current section!"); |
| |
| if (!getCurrentSectionData()->empty()) |
| return &getCurrentSectionData()->getFragmentList().back(); |
| |
| return 0; |
| } |
| |
| MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() const { |
| MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment()); |
| if (!F) |
| F = new MCDataFragment(getCurrentSectionData()); |
| return F; |
| } |
| |
| const MCExpr *MCObjectStreamer::AddValueSymbols(const MCExpr *Value) { |
| switch (Value->getKind()) { |
| case MCExpr::Target: |
| cast<MCTargetExpr>(Value)->AddValueSymbols(Assembler); |
| break; |
| |
| case MCExpr::Constant: |
| break; |
| |
| case MCExpr::Binary: { |
| const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value); |
| AddValueSymbols(BE->getLHS()); |
| AddValueSymbols(BE->getRHS()); |
| break; |
| } |
| |
| case MCExpr::SymbolRef: |
| Assembler->getOrCreateSymbolData(cast<MCSymbolRefExpr>(Value)->getSymbol()); |
| break; |
| |
| case MCExpr::Unary: |
| AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr()); |
| break; |
| } |
| |
| return Value; |
| } |
| |
| void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size, |
| unsigned AddrSpace) { |
| assert(AddrSpace == 0 && "Address space must be 0!"); |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| |
| // Avoid fixups when possible. |
| int64_t AbsValue; |
| if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue, getAssembler())) { |
| EmitIntValue(AbsValue, Size, AddrSpace); |
| return; |
| } |
| DF->addFixup(MCFixup::Create(DF->getContents().size(), |
| Value, |
| MCFixup::getKindForSize(Size, false))); |
| DF->getContents().resize(DF->getContents().size() + Size, 0); |
| } |
| |
| 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); |
| new MCLEBFragment(*Value, false, getCurrentSectionData()); |
| } |
| |
| void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value) { |
| int64_t IntValue; |
| if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) { |
| EmitSLEB128IntValue(IntValue); |
| return; |
| } |
| Value = ForceExpAbs(Value); |
| new MCLEBFragment(*Value, true, getCurrentSectionData()); |
| } |
| |
| 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) { |
| assert(Section && "Cannot switch to a null section!"); |
| |
| CurSectionData = &getAssembler().getOrCreateSectionData(*Section); |
| } |
| |
| void MCObjectStreamer::EmitInstruction(const MCInst &Inst) { |
| // Scan for values. |
| for (unsigned i = Inst.getNumOperands(); i--; ) |
| if (Inst.getOperand(i).isExpr()) |
| AddValueSymbols(Inst.getOperand(i).getExpr()); |
| |
| getCurrentSectionData()->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()); |
| |
| // If this instruction doesn't need relaxation, just emit it as data. |
| if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) { |
| EmitInstToData(Inst); |
| return; |
| } |
| |
| // Otherwise, if we are relaxing everything, relax the instruction as much as |
| // possible and emit it as data. |
| if (getAssembler().getRelaxAll()) { |
| MCInst Relaxed; |
| getAssembler().getBackend().RelaxInstruction(Inst, Relaxed); |
| while (getAssembler().getBackend().MayNeedRelaxation(Relaxed)) |
| getAssembler().getBackend().RelaxInstruction(Relaxed, Relaxed); |
| EmitInstToData(Relaxed); |
| return; |
| } |
| |
| // Otherwise emit to a separate fragment. |
| EmitInstToFragment(Inst); |
| } |
| |
| void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst) { |
| MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData()); |
| |
| SmallString<128> Code; |
| raw_svector_ostream VecOS(Code); |
| getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, IF->getFixups()); |
| VecOS.flush(); |
| IF->getCode().append(Code.begin(), Code.end()); |
| } |
| |
| 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); |
| new MCDwarfLineAddrFragment(LineDelta, *AddrDelta, getCurrentSectionData()); |
| } |
| |
| 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); |
| new MCDwarfCallFrameFragment(*AddrDelta, getCurrentSectionData()); |
| } |
| |
| void MCObjectStreamer::EmitValueToOffset(const MCExpr *Offset, |
| unsigned char Value) { |
| int64_t Res; |
| if (Offset->EvaluateAsAbsolute(Res, getAssembler())) { |
| new MCOrgFragment(*Offset, Value, getCurrentSectionData()); |
| return; |
| } |
| |
| 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())) |
| report_fatal_error("expected assembly-time absolute expression"); |
| EmitFill(Res, Value, 0); |
| } |
| |
| void MCObjectStreamer::Finish() { |
| // Dump out the dwarf file & directory tables and line tables. |
| if (getContext().hasDwarfFiles()) |
| MCDwarfFileTable::Emit(this); |
| |
| getAssembler().Finish(); |
| } |