llvm-6502/include/llvm/MC/MCObjectStreamer.h

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//===- 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/MC/MCStreamer.h"
namespace llvm {
class MCAssembler;
class MCCodeEmitter;
class MCSectionData;
class MCExpr;
class MCFragment;
class MCDataFragment;
class MCAsmBackend;
class raw_ostream;
/// \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;
MCSectionData *CurSectionData;
virtual void EmitInstToData(const MCInst &Inst) = 0;
virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame);
virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame);
protected:
MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
raw_ostream &_OS, MCCodeEmitter *_Emitter);
MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
raw_ostream &_OS, MCCodeEmitter *_Emitter,
MCAssembler *_Assembler);
~MCObjectStreamer();
public:
/// state management
virtual void reset();
protected:
MCSectionData *getCurrentSectionData() const {
return CurSectionData;
}
MCFragment *getCurrentFragment() const;
/// Get a data fragment to write into, creating a new one if the current
/// fragment is not a data fragment.
MCDataFragment *getOrCreateDataFragment() const;
const MCExpr *AddValueSymbols(const MCExpr *Value);
public:
MCAssembler &getAssembler() { return *Assembler; }
/// @name MCStreamer Interface
/// @{
virtual void EmitLabel(MCSymbol *Symbol);
This patch is needed to make c++ exceptions work for mips16. Mips16 is really a processor decoding mode (ala thumb 1) and in the same program, mips16 and mips32 functions can exist and can call each other. If a jal type instruction encounters an address with the lower bit set, then the processor switches to mips16 mode (if it is not already in it). If the lower bit is not set, then it switches to mips32 mode. The linker knows which functions are mips16 and which are mips32. When relocation is performed on code labels, this lower order bit is set if the code label is a mips16 code label. In general this works just fine, however when creating exception handling tables and dwarf, there are cases where you don't want this lower order bit added in. This has been traditionally distinguished in gas assembly source by using a different syntax for the label. lab1: ; this will cause the lower order bit to be added lab2=. ; this will not cause the lower order bit to be added In some cases, it does not matter because in dwarf and debug tables the difference of two labels is used and in that case the lower order bits subtract each other out. To fix this, I have added to mcstreamer the notion of a debuglabel. The default is for label and debug label to be the same. So calling EmitLabel and EmitDebugLabel produce the same result. For various reasons, there is only one set of labels that needs to be modified for the mips exceptions to work. These are the "$eh_func_beginXXX" labels. Mips overrides the debug label suffix from ":" to "=." . This initial patch fixes exceptions. More changes most likely will be needed to DwarfCFException to make all of this work for actual debugging. These changes will be to emit debug labels in some places where a simple label is emitted now. Some historical discussion on this from gcc can be found at: http://gcc.gnu.org/ml/gcc-patches/2008-08/msg00623.html http://gcc.gnu.org/ml/gcc-patches/2008-11/msg01273.html git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170279 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-16 04:00:45 +00:00
virtual void EmitDebugLabel(MCSymbol *Symbol);
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
unsigned AddrSpace);
virtual void EmitULEB128Value(const MCExpr *Value);
virtual void EmitSLEB128Value(const MCExpr *Value);
virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
virtual void ChangeSection(const MCSection *Section);
virtual void EmitInstruction(const MCInst &Inst);
/// \brief Emit an instruction to a special fragment, because this instruction
/// can change its size during relaxation.
virtual void EmitInstToFragment(const MCInst &Inst);
virtual void EmitBundleAlignMode(unsigned AlignPow2);
virtual void EmitBundleLock(bool AlignToEnd);
virtual void EmitBundleUnlock();
virtual void EmitBytes(StringRef Data, unsigned AddrSpace = 0);
virtual void EmitValueToAlignment(unsigned ByteAlignment,
int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0);
virtual void EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit = 0);
virtual bool EmitValueToOffset(const MCExpr *Offset, unsigned char Value);
virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
const MCSymbol *LastLabel,
const MCSymbol *Label,
unsigned PointerSize);
virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
const MCSymbol *Label);
virtual void EmitGPRel32Value(const MCExpr *Value);
virtual void EmitGPRel64Value(const MCExpr *Value);
virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
unsigned AddrSpace = 0);
virtual void FinishImpl();
/// @}
};
} // end namespace llvm
#endif