| //===- lib/MC/MCObjectStreamer.cpp - Object File MCStreamer Interface -----===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/MC/MCObjectStreamer.h" |
| #include "llvm/MC/MCAsmBackend.h" |
| #include "llvm/MC/MCAsmInfo.h" |
| #include "llvm/MC/MCAssembler.h" |
| #include "llvm/MC/MCCodeEmitter.h" |
| #include "llvm/MC/MCCodeView.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCDwarf.h" |
| #include "llvm/MC/MCExpr.h" |
| #include "llvm/MC/MCObjectFileInfo.h" |
| #include "llvm/MC/MCObjectWriter.h" |
| #include "llvm/MC/MCSection.h" |
| #include "llvm/MC/MCSymbol.h" |
| #include "llvm/MC/MCValue.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/SourceMgr.h" |
| using namespace llvm; |
| |
| MCObjectStreamer::MCObjectStreamer(MCContext &Context, |
| std::unique_ptr<MCAsmBackend> TAB, |
| std::unique_ptr<MCObjectWriter> OW, |
| std::unique_ptr<MCCodeEmitter> Emitter) |
| : MCStreamer(Context), |
| Assembler(std::make_unique<MCAssembler>( |
| Context, std::move(TAB), std::move(Emitter), std::move(OW))), |
| EmitEHFrame(true), EmitDebugFrame(false) { |
| assert(Assembler->getBackendPtr() && Assembler->getEmitterPtr()); |
| setAllowAutoPadding(Assembler->getBackend().allowAutoPadding()); |
| if (Context.getTargetOptions() && Context.getTargetOptions()->MCRelaxAll) |
| Assembler->setRelaxAll(true); |
| } |
| |
| MCObjectStreamer::~MCObjectStreamer() = default; |
| |
| MCAssembler *MCObjectStreamer::getAssemblerPtr() { |
| if (getUseAssemblerInfoForParsing()) |
| return Assembler.get(); |
| return nullptr; |
| } |
| |
| // When fixup's offset is a forward declared label, e.g.: |
| // |
| // .reloc 1f, R_MIPS_JALR, foo |
| // 1: nop |
| // |
| // postpone adding it to Fixups vector until the label is defined and its offset |
| // is known. |
| void MCObjectStreamer::resolvePendingFixups() { |
| for (PendingMCFixup &PendingFixup : PendingFixups) { |
| if (!PendingFixup.Sym || PendingFixup.Sym->isUndefined ()) { |
| getContext().reportError(PendingFixup.Fixup.getLoc(), |
| "unresolved relocation offset"); |
| continue; |
| } |
| PendingFixup.Fixup.setOffset(PendingFixup.Sym->getOffset() + |
| PendingFixup.Fixup.getOffset()); |
| |
| // If the location symbol to relocate is in MCEncodedFragmentWithFixups, |
| // put the Fixup into location symbol's fragment. Otherwise |
| // put into PendingFixup.DF |
| MCFragment *SymFragment = PendingFixup.Sym->getFragment(); |
| switch (SymFragment->getKind()) { |
| case MCFragment::FT_Relaxable: |
| case MCFragment::FT_Dwarf: |
| case MCFragment::FT_PseudoProbe: |
| cast<MCEncodedFragmentWithFixups<8, 1>>(SymFragment) |
| ->getFixups() |
| .push_back(PendingFixup.Fixup); |
| break; |
| case MCFragment::FT_Data: |
| case MCFragment::FT_CVDefRange: |
| cast<MCEncodedFragmentWithFixups<32, 4>>(SymFragment) |
| ->getFixups() |
| .push_back(PendingFixup.Fixup); |
| break; |
| default: |
| PendingFixup.DF->getFixups().push_back(PendingFixup.Fixup); |
| break; |
| } |
| } |
| PendingFixups.clear(); |
| } |
| |
| // As a compile-time optimization, avoid allocating and evaluating an MCExpr |
| // tree for (Hi - Lo) when Hi and Lo are offsets into the same fragment. |
| static std::optional<uint64_t> absoluteSymbolDiff(const MCSymbol *Hi, |
| const MCSymbol *Lo) { |
| assert(Hi && Lo); |
| if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment() || |
| Hi->isVariable() || Lo->isVariable()) |
| return std::nullopt; |
| |
| return Hi->getOffset() - Lo->getOffset(); |
| } |
| |
| void MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi, |
| const MCSymbol *Lo, |
| unsigned Size) { |
| if (!getAssembler().getContext().getTargetTriple().isRISCV()) |
| if (std::optional<uint64_t> Diff = absoluteSymbolDiff(Hi, Lo)) |
| return emitIntValue(*Diff, Size); |
| MCStreamer::emitAbsoluteSymbolDiff(Hi, Lo, Size); |
| } |
| |
| void MCObjectStreamer::emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi, |
| const MCSymbol *Lo) { |
| if (!getAssembler().getContext().getTargetTriple().isRISCV()) |
| if (std::optional<uint64_t> Diff = absoluteSymbolDiff(Hi, Lo)) { |
| emitULEB128IntValue(*Diff); |
| return; |
| } |
| MCStreamer::emitAbsoluteSymbolDiffAsULEB128(Hi, Lo); |
| } |
| |
| void MCObjectStreamer::reset() { |
| if (Assembler) { |
| Assembler->reset(); |
| if (getContext().getTargetOptions()) |
| Assembler->setRelaxAll(getContext().getTargetOptions()->MCRelaxAll); |
| } |
| 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); |
| } |
| |
| static bool canReuseDataFragment(const MCDataFragment &F, |
| const MCAssembler &Assembler, |
| const MCSubtargetInfo *STI) { |
| if (!F.hasInstructions()) |
| return true; |
| // Do not add data after a linker-relaxable instruction. The difference |
| // between a new label and a label at or before the linker-relaxable |
| // instruction cannot be resolved at assemble-time. |
| if (F.isLinkerRelaxable()) |
| return false; |
| // When bundling is enabled, we don't want to add data to a fragment that |
| // already has instructions (see MCELFStreamer::emitInstToData for details) |
| if (Assembler.isBundlingEnabled()) |
| return false; |
| // If the subtarget is changed mid fragment we start a new fragment to record |
| // the new STI. |
| return !STI || F.getSubtargetInfo() == STI; |
| } |
| |
| MCDataFragment * |
| MCObjectStreamer::getOrCreateDataFragment(const MCSubtargetInfo *STI) { |
| auto *F = dyn_cast<MCDataFragment>(getCurrentFragment()); |
| if (!F || !canReuseDataFragment(*F, *Assembler, STI)) { |
| F = getContext().allocFragment<MCDataFragment>(); |
| insert(F); |
| } |
| return F; |
| } |
| |
| void MCObjectStreamer::visitUsedSymbol(const MCSymbol &Sym) { |
| Assembler->registerSymbol(Sym); |
| } |
| |
| void MCObjectStreamer::emitCFISections(bool EH, bool Debug) { |
| MCStreamer::emitCFISections(EH, Debug); |
| EmitEHFrame = EH; |
| EmitDebugFrame = Debug; |
| } |
| |
| void MCObjectStreamer::emitValueImpl(const MCExpr *Value, unsigned Size, |
| SMLoc Loc) { |
| MCStreamer::emitValueImpl(Value, Size, Loc); |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| |
| MCDwarfLineEntry::make(this, getCurrentSectionOnly()); |
| |
| // Avoid fixups when possible. |
| int64_t AbsValue; |
| if (Value->evaluateAsAbsolute(AbsValue, getAssemblerPtr())) { |
| if (!isUIntN(8 * Size, AbsValue) && !isIntN(8 * Size, AbsValue)) { |
| getContext().reportError( |
| Loc, "value evaluated as " + Twine(AbsValue) + " is out of range."); |
| return; |
| } |
| 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); |
| } |
| |
| MCSymbol *MCObjectStreamer::emitCFILabel() { |
| MCSymbol *Label = getContext().createTempSymbol("cfi"); |
| emitLabel(Label); |
| return Label; |
| } |
| |
| 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, SMLoc Loc) { |
| MCStreamer::emitLabel(Symbol, Loc); |
| |
| getAssembler().registerSymbol(*Symbol); |
| |
| // If there is a current fragment, mark the symbol as pointing into it. |
| // Otherwise queue the label and set its fragment pointer when we emit the |
| // next fragment. |
| MCDataFragment *F = getOrCreateDataFragment(); |
| Symbol->setFragment(F); |
| Symbol->setOffset(F->getContents().size()); |
| |
| emitPendingAssignments(Symbol); |
| } |
| |
| void MCObjectStreamer::emitPendingAssignments(MCSymbol *Symbol) { |
| auto Assignments = pendingAssignments.find(Symbol); |
| if (Assignments != pendingAssignments.end()) { |
| for (const PendingAssignment &A : Assignments->second) |
| emitAssignment(A.Symbol, A.Value); |
| |
| pendingAssignments.erase(Assignments); |
| } |
| } |
| |
| // Emit a label at a previously emitted fragment/offset position. This must be |
| // within the currently-active section. |
| void MCObjectStreamer::emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, |
| MCDataFragment &F, uint64_t Offset) { |
| assert(F.getParent() == getCurrentSectionOnly()); |
| MCStreamer::emitLabel(Symbol, Loc); |
| getAssembler().registerSymbol(*Symbol); |
| Symbol->setFragment(&F); |
| Symbol->setOffset(Offset); |
| } |
| |
| void MCObjectStreamer::emitULEB128Value(const MCExpr *Value) { |
| int64_t IntValue; |
| if (Value->evaluateAsAbsolute(IntValue, getAssemblerPtr())) { |
| emitULEB128IntValue(IntValue); |
| return; |
| } |
| insert(getContext().allocFragment<MCLEBFragment>(*Value, false)); |
| } |
| |
| void MCObjectStreamer::emitSLEB128Value(const MCExpr *Value) { |
| int64_t IntValue; |
| if (Value->evaluateAsAbsolute(IntValue, getAssemblerPtr())) { |
| emitSLEB128IntValue(IntValue); |
| return; |
| } |
| insert(getContext().allocFragment<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(MCSection *Section, uint32_t Subsection) { |
| changeSectionImpl(Section, Subsection); |
| } |
| |
| bool MCObjectStreamer::changeSectionImpl(MCSection *Section, |
| uint32_t Subsection) { |
| assert(Section && "Cannot switch to a null section!"); |
| getContext().clearDwarfLocSeen(); |
| |
| auto &Subsections = Section->Subsections; |
| size_t I = 0, E = Subsections.size(); |
| while (I != E && Subsections[I].first < Subsection) |
| ++I; |
| // If the subsection number is not in the sorted Subsections list, create a |
| // new fragment list. |
| if (I == E || Subsections[I].first != Subsection) { |
| auto *F = getContext().allocFragment<MCDataFragment>(); |
| F->setParent(Section); |
| Subsections.insert(Subsections.begin() + I, |
| {Subsection, MCSection::FragList{F, F}}); |
| } |
| Section->CurFragList = &Subsections[I].second; |
| CurFrag = Section->CurFragList->Tail; |
| |
| return getAssembler().registerSection(*Section); |
| } |
| |
| void MCObjectStreamer::switchSectionNoPrint(MCSection *Section) { |
| MCStreamer::switchSectionNoPrint(Section); |
| changeSection(Section, 0); |
| } |
| |
| void MCObjectStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) { |
| getAssembler().registerSymbol(*Symbol); |
| MCStreamer::emitAssignment(Symbol, Value); |
| emitPendingAssignments(Symbol); |
| } |
| |
| void MCObjectStreamer::emitConditionalAssignment(MCSymbol *Symbol, |
| const MCExpr *Value) { |
| const MCSymbol *Target = &cast<MCSymbolRefExpr>(*Value).getSymbol(); |
| |
| // If the symbol already exists, emit the assignment. Otherwise, emit it |
| // later only if the symbol is also emitted. |
| if (Target->isRegistered()) |
| emitAssignment(Symbol, Value); |
| else |
| pendingAssignments[Target].push_back({Symbol, Value}); |
| } |
| |
| bool MCObjectStreamer::mayHaveInstructions(MCSection &Sec) const { |
| return Sec.hasInstructions(); |
| } |
| |
| void MCObjectStreamer::emitInstruction(const MCInst &Inst, |
| const MCSubtargetInfo &STI) { |
| const MCSection &Sec = *getCurrentSectionOnly(); |
| if (Sec.isVirtualSection()) { |
| getContext().reportError(Inst.getLoc(), Twine(Sec.getVirtualSectionKind()) + |
| " section '" + Sec.getName() + |
| "' cannot have instructions"); |
| return; |
| } |
| emitInstructionImpl(Inst, STI); |
| } |
| |
| void MCObjectStreamer::emitInstructionImpl(const MCInst &Inst, |
| const MCSubtargetInfo &STI) { |
| MCStreamer::emitInstruction(Inst, STI); |
| |
| MCSection *Sec = getCurrentSectionOnly(); |
| Sec->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. |
| MCDwarfLineEntry::make(this, getCurrentSectionOnly()); |
| |
| // If this instruction doesn't need relaxation, just emit it as data. |
| MCAssembler &Assembler = getAssembler(); |
| MCAsmBackend &Backend = Assembler.getBackend(); |
| if (!(Backend.mayNeedRelaxation(Inst, STI) || |
| Backend.allowEnhancedRelaxation())) { |
| 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() && Sec->isBundleLocked())) { |
| MCInst Relaxed = Inst; |
| while (Backend.mayNeedRelaxation(Relaxed, STI)) |
| Backend.relaxInstruction(Relaxed, STI); |
| 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 = |
| getContext().allocFragment<MCRelaxableFragment>(Inst, STI); |
| insert(IF); |
| |
| getAssembler().getEmitter().encodeInstruction(Inst, IF->getContents(), |
| IF->getFixups(), STI); |
| } |
| |
| #ifndef NDEBUG |
| static const char *const BundlingNotImplementedMsg = |
| "Aligned bundling is not implemented for this object format"; |
| #endif |
| |
| void MCObjectStreamer::emitBundleAlignMode(Align Alignment) { |
| 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. |
| MCDwarfLineEntry::make(this, getCurrentSectionOnly()); |
| |
| this->MCStreamer::emitDwarfLocDirective(FileNo, Line, Column, Flags, Isa, |
| Discriminator, FileName); |
| } |
| |
| static const MCExpr *buildSymbolDiff(MCObjectStreamer &OS, const MCSymbol *A, |
| const MCSymbol *B, SMLoc Loc) { |
| MCContext &Context = OS.getContext(); |
| MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None; |
| const MCExpr *ARef = MCSymbolRefExpr::create(A, Variant, Context); |
| const MCExpr *BRef = MCSymbolRefExpr::create(B, Variant, Context); |
| const MCExpr *AddrDelta = |
| MCBinaryExpr::create(MCBinaryExpr::Sub, ARef, BRef, Context, Loc); |
| return AddrDelta; |
| } |
| |
| static void emitDwarfSetLineAddr(MCObjectStreamer &OS, |
| MCDwarfLineTableParams Params, |
| int64_t LineDelta, const MCSymbol *Label, |
| int PointerSize) { |
| // emit the sequence to set the address |
| OS.emitIntValue(dwarf::DW_LNS_extended_op, 1); |
| OS.emitULEB128IntValue(PointerSize + 1); |
| OS.emitIntValue(dwarf::DW_LNE_set_address, 1); |
| OS.emitSymbolValue(Label, PointerSize); |
| |
| // emit the sequence for the LineDelta (from 1) and a zero address delta. |
| MCDwarfLineAddr::Emit(&OS, Params, LineDelta, 0); |
| } |
| |
| void MCObjectStreamer::emitDwarfAdvanceLineAddr(int64_t LineDelta, |
| const MCSymbol *LastLabel, |
| const MCSymbol *Label, |
| unsigned PointerSize) { |
| if (!LastLabel) { |
| emitDwarfSetLineAddr(*this, Assembler->getDWARFLinetableParams(), LineDelta, |
| Label, PointerSize); |
| return; |
| } |
| const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel, SMLoc()); |
| insert(getContext().allocFragment<MCDwarfLineAddrFragment>(LineDelta, |
| *AddrDelta)); |
| } |
| |
| void MCObjectStreamer::emitDwarfLineEndEntry(MCSection *Section, |
| MCSymbol *LastLabel) { |
| // Emit a DW_LNE_end_sequence for the end of the section. |
| // Use the section end label to compute the address delta and use INT64_MAX |
| // as the line delta which is the signal that this is actually a |
| // DW_LNE_end_sequence. |
| MCSymbol *SectionEnd = endSection(Section); |
| |
| // Switch back the dwarf line section, in case endSection had to switch the |
| // section. |
| MCContext &Ctx = getContext(); |
| switchSection(Ctx.getObjectFileInfo()->getDwarfLineSection()); |
| |
| const MCAsmInfo *AsmInfo = Ctx.getAsmInfo(); |
| emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd, |
| AsmInfo->getCodePointerSize()); |
| } |
| |
| void MCObjectStreamer::emitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, |
| const MCSymbol *Label, |
| SMLoc Loc) { |
| const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel, Loc); |
| insert(getContext().allocFragment<MCDwarfCallFrameFragment>(*AddrDelta)); |
| } |
| |
| void MCObjectStreamer::emitCVLocDirective(unsigned FunctionId, unsigned FileNo, |
| unsigned Line, unsigned Column, |
| bool PrologueEnd, bool IsStmt, |
| StringRef FileName, SMLoc Loc) { |
| // Validate the directive. |
| if (!checkCVLocSection(FunctionId, FileNo, Loc)) |
| return; |
| |
| // Emit a label at the current position and record it in the CodeViewContext. |
| MCSymbol *LineSym = getContext().createTempSymbol(); |
| emitLabel(LineSym); |
| getContext().getCVContext().recordCVLoc(getContext(), LineSym, FunctionId, |
| FileNo, Line, Column, PrologueEnd, |
| IsStmt); |
| } |
| |
| void MCObjectStreamer::emitCVLinetableDirective(unsigned FunctionId, |
| const MCSymbol *Begin, |
| const MCSymbol *End) { |
| getContext().getCVContext().emitLineTableForFunction(*this, FunctionId, Begin, |
| End); |
| this->MCStreamer::emitCVLinetableDirective(FunctionId, Begin, End); |
| } |
| |
| void MCObjectStreamer::emitCVInlineLinetableDirective( |
| unsigned PrimaryFunctionId, unsigned SourceFileId, unsigned SourceLineNum, |
| const MCSymbol *FnStartSym, const MCSymbol *FnEndSym) { |
| getContext().getCVContext().emitInlineLineTableForFunction( |
| *this, PrimaryFunctionId, SourceFileId, SourceLineNum, FnStartSym, |
| FnEndSym); |
| this->MCStreamer::emitCVInlineLinetableDirective( |
| PrimaryFunctionId, SourceFileId, SourceLineNum, FnStartSym, FnEndSym); |
| } |
| |
| void MCObjectStreamer::emitCVDefRangeDirective( |
| ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges, |
| StringRef FixedSizePortion) { |
| getContext().getCVContext().emitDefRange(*this, Ranges, FixedSizePortion); |
| // Attach labels that were pending before we created the defrange fragment to |
| // the beginning of the new fragment. |
| this->MCStreamer::emitCVDefRangeDirective(Ranges, FixedSizePortion); |
| } |
| |
| void MCObjectStreamer::emitCVStringTableDirective() { |
| getContext().getCVContext().emitStringTable(*this); |
| } |
| void MCObjectStreamer::emitCVFileChecksumsDirective() { |
| getContext().getCVContext().emitFileChecksums(*this); |
| } |
| |
| void MCObjectStreamer::emitCVFileChecksumOffsetDirective(unsigned FileNo) { |
| getContext().getCVContext().emitFileChecksumOffset(*this, FileNo); |
| } |
| |
| void MCObjectStreamer::emitBytes(StringRef Data) { |
| MCDwarfLineEntry::make(this, getCurrentSectionOnly()); |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| DF->getContents().append(Data.begin(), Data.end()); |
| } |
| |
| void MCObjectStreamer::emitValueToAlignment(Align Alignment, int64_t Value, |
| unsigned ValueSize, |
| unsigned MaxBytesToEmit) { |
| if (MaxBytesToEmit == 0) |
| MaxBytesToEmit = Alignment.value(); |
| insert(getContext().allocFragment<MCAlignFragment>( |
| Alignment, Value, ValueSize, MaxBytesToEmit)); |
| |
| // Update the maximum alignment on the current section if necessary. |
| MCSection *CurSec = getCurrentSectionOnly(); |
| CurSec->ensureMinAlignment(Alignment); |
| } |
| |
| void MCObjectStreamer::emitCodeAlignment(Align Alignment, |
| const MCSubtargetInfo *STI, |
| unsigned MaxBytesToEmit) { |
| emitValueToAlignment(Alignment, 0, 1, MaxBytesToEmit); |
| cast<MCAlignFragment>(getCurrentFragment())->setEmitNops(true, STI); |
| } |
| |
| void MCObjectStreamer::emitValueToOffset(const MCExpr *Offset, |
| unsigned char Value, |
| SMLoc Loc) { |
| insert(getContext().allocFragment<MCOrgFragment>(*Offset, Value, Loc)); |
| } |
| |
| // Associate DTPRel32 fixup with data and resize data area |
| void MCObjectStreamer::emitDTPRel32Value(const MCExpr *Value) { |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| DF->getFixups().push_back(MCFixup::create(DF->getContents().size(), |
| Value, FK_DTPRel_4)); |
| DF->getContents().resize(DF->getContents().size() + 4, 0); |
| } |
| |
| // Associate DTPRel64 fixup with data and resize data area |
| void MCObjectStreamer::emitDTPRel64Value(const MCExpr *Value) { |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| DF->getFixups().push_back(MCFixup::create(DF->getContents().size(), |
| Value, FK_DTPRel_8)); |
| DF->getContents().resize(DF->getContents().size() + 8, 0); |
| } |
| |
| // Associate TPRel32 fixup with data and resize data area |
| void MCObjectStreamer::emitTPRel32Value(const MCExpr *Value) { |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| DF->getFixups().push_back(MCFixup::create(DF->getContents().size(), |
| Value, FK_TPRel_4)); |
| DF->getContents().resize(DF->getContents().size() + 4, 0); |
| } |
| |
| // Associate TPRel64 fixup with data and resize data area |
| void MCObjectStreamer::emitTPRel64Value(const MCExpr *Value) { |
| MCDataFragment *DF = getOrCreateDataFragment(); |
| DF->getFixups().push_back(MCFixup::create(DF->getContents().size(), |
| Value, FK_TPRel_8)); |
| DF->getContents().resize(DF->getContents().size() + 8, 0); |
| } |
| |
| // 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 GPRel64 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); |
| } |
| |
| static std::optional<std::pair<bool, std::string>> |
| getOffsetAndDataFragment(const MCSymbol &Symbol, uint32_t &RelocOffset, |
| MCDataFragment *&DF) { |
| if (Symbol.isVariable()) { |
| const MCExpr *SymbolExpr = Symbol.getVariableValue(); |
| MCValue OffsetVal; |
| if(!SymbolExpr->evaluateAsRelocatable(OffsetVal, nullptr, nullptr)) |
| return std::make_pair(false, |
| std::string("symbol in .reloc offset is not " |
| "relocatable")); |
| if (OffsetVal.isAbsolute()) { |
| RelocOffset = OffsetVal.getConstant(); |
| MCFragment *Fragment = Symbol.getFragment(); |
| // FIXME Support symbols with no DF. For example: |
| // .reloc .data, ENUM_VALUE, <some expr> |
| if (!Fragment || Fragment->getKind() != MCFragment::FT_Data) |
| return std::make_pair(false, |
| std::string("symbol in offset has no data " |
| "fragment")); |
| DF = cast<MCDataFragment>(Fragment); |
| return std::nullopt; |
| } |
| |
| if (OffsetVal.getSymB()) |
| return std::make_pair(false, |
| std::string(".reloc symbol offset is not " |
| "representable")); |
| |
| const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*OffsetVal.getSymA()); |
| if (!SRE.getSymbol().isDefined()) |
| return std::make_pair(false, |
| std::string("symbol used in the .reloc offset is " |
| "not defined")); |
| |
| if (SRE.getSymbol().isVariable()) |
| return std::make_pair(false, |
| std::string("symbol used in the .reloc offset is " |
| "variable")); |
| |
| MCFragment *Fragment = SRE.getSymbol().getFragment(); |
| // FIXME Support symbols with no DF. For example: |
| // .reloc .data, ENUM_VALUE, <some expr> |
| if (!Fragment || Fragment->getKind() != MCFragment::FT_Data) |
| return std::make_pair(false, |
| std::string("symbol in offset has no data " |
| "fragment")); |
| RelocOffset = SRE.getSymbol().getOffset() + OffsetVal.getConstant(); |
| DF = cast<MCDataFragment>(Fragment); |
| } else { |
| RelocOffset = Symbol.getOffset(); |
| MCFragment *Fragment = Symbol.getFragment(); |
| // FIXME Support symbols with no DF. For example: |
| // .reloc .data, ENUM_VALUE, <some expr> |
| if (!Fragment || Fragment->getKind() != MCFragment::FT_Data) |
| return std::make_pair(false, |
| std::string("symbol in offset has no data " |
| "fragment")); |
| DF = cast<MCDataFragment>(Fragment); |
| } |
| return std::nullopt; |
| } |
| |
| std::optional<std::pair<bool, std::string>> |
| MCObjectStreamer::emitRelocDirective(const MCExpr &Offset, StringRef Name, |
| const MCExpr *Expr, SMLoc Loc, |
| const MCSubtargetInfo &STI) { |
| std::optional<MCFixupKind> MaybeKind = |
| Assembler->getBackend().getFixupKind(Name); |
| if (!MaybeKind) |
| return std::make_pair(true, std::string("unknown relocation name")); |
| |
| MCFixupKind Kind = *MaybeKind; |
| if (Expr) |
| visitUsedExpr(*Expr); |
| else |
| Expr = |
| MCSymbolRefExpr::create(getContext().createTempSymbol(), getContext()); |
| |
| MCDataFragment *DF = getOrCreateDataFragment(&STI); |
| MCValue OffsetVal; |
| if (!Offset.evaluateAsRelocatable(OffsetVal, nullptr, nullptr)) |
| return std::make_pair(false, |
| std::string(".reloc offset is not relocatable")); |
| if (OffsetVal.isAbsolute()) { |
| if (OffsetVal.getConstant() < 0) |
| return std::make_pair(false, std::string(".reloc offset is negative")); |
| DF->getFixups().push_back( |
| MCFixup::create(OffsetVal.getConstant(), Expr, Kind, Loc)); |
| return std::nullopt; |
| } |
| if (OffsetVal.getSymB()) |
| return std::make_pair(false, |
| std::string(".reloc offset is not representable")); |
| |
| const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*OffsetVal.getSymA()); |
| const MCSymbol &Symbol = SRE.getSymbol(); |
| if (Symbol.isDefined()) { |
| uint32_t SymbolOffset = 0; |
| std::optional<std::pair<bool, std::string>> Error = |
| getOffsetAndDataFragment(Symbol, SymbolOffset, DF); |
| |
| if (Error != std::nullopt) |
| return Error; |
| |
| DF->getFixups().push_back( |
| MCFixup::create(SymbolOffset + OffsetVal.getConstant(), |
| Expr, Kind, Loc)); |
| return std::nullopt; |
| } |
| |
| PendingFixups.emplace_back( |
| &SRE.getSymbol(), DF, |
| MCFixup::create(OffsetVal.getConstant(), Expr, Kind, Loc)); |
| return std::nullopt; |
| } |
| |
| void MCObjectStreamer::emitFill(const MCExpr &NumBytes, uint64_t FillValue, |
| SMLoc Loc) { |
| assert(getCurrentSectionOnly() && "need a section"); |
| insert( |
| getContext().allocFragment<MCFillFragment>(FillValue, 1, NumBytes, Loc)); |
| } |
| |
| void MCObjectStreamer::emitFill(const MCExpr &NumValues, int64_t Size, |
| int64_t Expr, SMLoc Loc) { |
| int64_t IntNumValues; |
| // Do additional checking now if we can resolve the value. |
| if (NumValues.evaluateAsAbsolute(IntNumValues, getAssemblerPtr())) { |
| if (IntNumValues < 0) { |
| getContext().getSourceManager()->PrintMessage( |
| Loc, SourceMgr::DK_Warning, |
| "'.fill' directive with negative repeat count has no effect"); |
| return; |
| } |
| // Emit now if we can for better errors. |
| int64_t NonZeroSize = Size > 4 ? 4 : Size; |
| Expr &= ~0ULL >> (64 - NonZeroSize * 8); |
| for (uint64_t i = 0, e = IntNumValues; i != e; ++i) { |
| emitIntValue(Expr, NonZeroSize); |
| if (NonZeroSize < Size) |
| emitIntValue(0, Size - NonZeroSize); |
| } |
| return; |
| } |
| |
| // Otherwise emit as fragment. |
| assert(getCurrentSectionOnly() && "need a section"); |
| insert( |
| getContext().allocFragment<MCFillFragment>(Expr, Size, NumValues, Loc)); |
| } |
| |
| void MCObjectStreamer::emitNops(int64_t NumBytes, int64_t ControlledNopLength, |
| SMLoc Loc, const MCSubtargetInfo &STI) { |
| assert(getCurrentSectionOnly() && "need a section"); |
| insert(getContext().allocFragment<MCNopsFragment>( |
| NumBytes, ControlledNopLength, Loc, STI)); |
| } |
| |
| void MCObjectStreamer::emitFileDirective(StringRef Filename) { |
| MCAssembler &Asm = getAssembler(); |
| Asm.getWriter().addFileName(Asm, Filename); |
| } |
| |
| void MCObjectStreamer::emitFileDirective(StringRef Filename, |
| StringRef CompilerVersion, |
| StringRef TimeStamp, |
| StringRef Description) { |
| MCObjectWriter &W = getAssembler().getWriter(); |
| W.addFileName(getAssembler(), Filename); |
| if (CompilerVersion.size()) |
| W.setCompilerVersion(CompilerVersion); |
| // TODO: add TimeStamp and Description to .file symbol table entry |
| // with the integrated assembler. |
| } |
| |
| void MCObjectStreamer::emitAddrsig() { |
| getAssembler().getWriter().emitAddrsigSection(); |
| } |
| |
| void MCObjectStreamer::emitAddrsigSym(const MCSymbol *Sym) { |
| getAssembler().getWriter().addAddrsigSymbol(Sym); |
| } |
| |
| void MCObjectStreamer::finishImpl() { |
| getContext().RemapDebugPaths(); |
| |
| // 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().getDWARFLinetableParams()); |
| |
| // Emit pseudo probes for the current module. |
| MCPseudoProbeTable::emit(this); |
| |
| resolvePendingFixups(); |
| getAssembler().Finish(); |
| } |