//===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===// // // 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 // //===----------------------------------------------------------------------===// #ifndef LLVM_MC_MCOBJECTSTREAMER_H #define LLVM_MC_MCOBJECTSTREAMER_H #include "llvm/ADT/SetVector.h" #include "llvm/ADT/SmallVector.h" #include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCSection.h" #include "llvm/MC/MCStreamer.h" namespace llvm { class MCAssembler; class MCCodeEmitter; class MCSubtargetInfo; class MCExpr; class MCFragment; class MCDataFragment; class MCAsmBackend; class raw_ostream; class raw_pwrite_stream; /// Streaming object file generation interface. /// /// This class provides an implementation of the MCStreamer interface which is /// suitable for use with the assembler backend. Specific object file formats /// are expected to subclass this interface to implement directives specific /// to that file format or custom semantics expected by the object writer /// implementation. class MCObjectStreamer : public MCStreamer { std::unique_ptr Assembler; MCSection::iterator CurInsertionPoint; bool EmitEHFrame; bool EmitDebugFrame; SmallVector PendingLabels; SmallSetVector PendingLabelSections; unsigned CurSubsectionIdx; struct PendingMCFixup { const MCSymbol *Sym; MCFixup Fixup; MCDataFragment *DF; PendingMCFixup(const MCSymbol *McSym, MCDataFragment *F, MCFixup McFixup) : Sym(McSym), Fixup(McFixup), DF(F) {} }; SmallVector PendingFixups; virtual void emitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0; void emitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override; void emitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override; MCSymbol *emitCFILabel() override; void emitInstructionImpl(const MCInst &Inst, const MCSubtargetInfo &STI); void resolvePendingFixups(); protected: MCObjectStreamer(MCContext &Context, std::unique_ptr TAB, std::unique_ptr OW, std::unique_ptr Emitter); ~MCObjectStreamer(); public: /// state management void reset() override; /// Object streamers require the integrated assembler. bool isIntegratedAssemblerRequired() const override { return true; } void emitFrames(MCAsmBackend *MAB); void emitCFISections(bool EH, bool Debug) override; MCFragment *getCurrentFragment() const; void insert(MCFragment *F) { flushPendingLabels(F); MCSection *CurSection = getCurrentSectionOnly(); CurSection->getFragmentList().insert(CurInsertionPoint, F); F->setParent(CurSection); } /// Get a data fragment to write into, creating a new one if the current /// fragment is not a data fragment. /// Optionally a \p STI can be passed in so that a new fragment is created /// if the Subtarget differs from the current fragment. MCDataFragment *getOrCreateDataFragment(const MCSubtargetInfo* STI = nullptr); protected: bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection); /// Assign a label to the current Section and Subsection even though a /// fragment is not yet present. Use flushPendingLabels(F) to associate /// a fragment with this label. void addPendingLabel(MCSymbol* label); /// If any labels have been emitted but not assigned fragments in the current /// Section and Subsection, ensure that they get assigned, either to fragment /// F if possible or to a new data fragment. Optionally, one can provide an /// offset \p FOffset as a symbol offset within the fragment. void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0); public: void visitUsedSymbol(const MCSymbol &Sym) override; /// Create a data fragment for any pending labels across all Sections /// and Subsections. void flushPendingLabels(); MCAssembler &getAssembler() { return *Assembler; } MCAssembler *getAssemblerPtr() override; /// \name MCStreamer Interface /// @{ void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override; virtual void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F, uint64_t Offset); void emitAssignment(MCSymbol *Symbol, const MCExpr *Value) override; void emitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc = SMLoc()) override; void emitULEB128Value(const MCExpr *Value) override; void emitSLEB128Value(const MCExpr *Value) override; void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override; void changeSection(MCSection *Section, const MCExpr *Subsection) override; void emitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override; /// Emit an instruction to a special fragment, because this instruction /// can change its size during relaxation. virtual void emitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &); void emitBundleAlignMode(unsigned AlignPow2) override; void emitBundleLock(bool AlignToEnd) override; void emitBundleUnlock() override; void emitBytes(StringRef Data) override; void emitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, unsigned ValueSize = 1, unsigned MaxBytesToEmit = 0) override; void emitCodeAlignment(unsigned ByteAlignment, unsigned MaxBytesToEmit = 0) override; void emitValueToOffset(const MCExpr *Offset, unsigned char Value, SMLoc Loc) override; void emitDwarfLocDirective(unsigned FileNo, unsigned Line, unsigned Column, unsigned Flags, unsigned Isa, unsigned Discriminator, StringRef FileName) override; void emitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, const MCSymbol *Label, unsigned PointerSize) override; void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel) override; void emitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, const MCSymbol *Label); void emitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line, unsigned Column, bool PrologueEnd, bool IsStmt, StringRef FileName, SMLoc Loc) override; void emitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin, const MCSymbol *End) override; void emitCVInlineLinetableDirective(unsigned PrimaryFunctionId, unsigned SourceFileId, unsigned SourceLineNum, const MCSymbol *FnStartSym, const MCSymbol *FnEndSym) override; void emitCVDefRangeDirective( ArrayRef> Ranges, StringRef FixedSizePortion) override; void emitCVStringTableDirective() override; void emitCVFileChecksumsDirective() override; void emitCVFileChecksumOffsetDirective(unsigned FileNo) override; void emitDTPRel32Value(const MCExpr *Value) override; void emitDTPRel64Value(const MCExpr *Value) override; void emitTPRel32Value(const MCExpr *Value) override; void emitTPRel64Value(const MCExpr *Value) override; void emitGPRel32Value(const MCExpr *Value) override; void emitGPRel64Value(const MCExpr *Value) override; Optional> emitRelocDirective(const MCExpr &Offset, StringRef Name, const MCExpr *Expr, SMLoc Loc, const MCSubtargetInfo &STI) override; using MCStreamer::emitFill; void emitFill(const MCExpr &NumBytes, uint64_t FillValue, SMLoc Loc = SMLoc()) override; void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr, SMLoc Loc = SMLoc()) override; void emitNops(int64_t NumBytes, int64_t ControlledNopLength, SMLoc Loc) override; void emitFileDirective(StringRef Filename) override; void emitAddrsig() override; void emitAddrsigSym(const MCSymbol *Sym) override; void finishImpl() override; /// Emit the absolute difference between two symbols if possible. /// /// Emit the absolute difference between \c Hi and \c Lo, as long as we can /// compute it. Currently, that requires that both symbols are in the same /// data fragment and that the target has not specified that diff expressions /// require relocations to be emitted. Otherwise, do nothing and return /// \c false. /// /// \pre Offset of \c Hi is greater than the offset \c Lo. void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo, unsigned Size) override; void emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi, const MCSymbol *Lo) override; bool mayHaveInstructions(MCSection &Sec) const override; }; } // end namespace llvm #endif