llvm-6502/include/llvm/MC/MCObjectStreamer.h
2015-06-11 23:04:56 +00:00

147 lines
5.6 KiB
C++

//===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCOBJECTSTREAMER_H
#define LLVM_MC_MCOBJECTSTREAMER_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;
/// \brief 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 {
MCAssembler *Assembler;
MCSection::iterator CurInsertionPoint;
bool EmitEHFrame;
bool EmitDebugFrame;
SmallVector<MCSymbol *, 2> PendingLabels;
virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0;
void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
protected:
MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS,
MCCodeEmitter *Emitter);
~MCObjectStreamer() override;
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;
protected:
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.
MCDataFragment *getOrCreateDataFragment();
bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection);
/// If any labels have been emitted but not assigned fragments, ensure that
/// they get assigned, either to F if possible or to a new data fragment.
/// Optionally, it is also possible to provide an offset \p FOffset, which
/// will be used as a symbol offset within the fragment.
void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0);
public:
void visitUsedSymbol(const MCSymbol &Sym) override;
MCAssembler &getAssembler() { return *Assembler; }
/// \name MCStreamer Interface
/// @{
void EmitLabel(MCSymbol *Symbol) override;
void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
void EmitValueImpl(const MCExpr *Value, unsigned Size,
const 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;
/// \brief 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;
bool EmitValueToOffset(const MCExpr *Offset, unsigned char Value) 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);
void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
const MCSymbol *Label);
void EmitGPRel32Value(const MCExpr *Value) override;
void EmitGPRel64Value(const MCExpr *Value) override;
void EmitFill(uint64_t NumBytes, uint8_t FillValue) override;
void EmitZeros(uint64_t NumBytes) 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. 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;
bool mayHaveInstructions(MCSection &Sec) const override;
};
} // end namespace llvm
#endif