llvm-6502/include/llvm/MC/MCCodeEmitter.h
2010-03-19 10:43:23 +00:00

81 lines
2.3 KiB
C++

//===-- llvm/MC/MCCodeEmitter.h - Instruction Encoding ----------*- 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_MCCODEEMITTER_H
#define LLVM_MC_MCCODEEMITTER_H
#include "llvm/MC/MCFixup.h"
#include <cassert>
namespace llvm {
class MCExpr;
class MCInst;
class raw_ostream;
template<typename T> class SmallVectorImpl;
/// MCFixupKindInfo - Target independent information on a fixup kind.
struct MCFixupKindInfo {
enum FixupKindFlags {
/// Is this fixup kind PCrelative. This is used by the assembler backend to
/// evaluate fixup values in a target independent manner when possible.
FKF_IsPCRel = (1 << 0)
};
/// A target specific name for the fixup kind. The names will be unique for
/// distinct kinds on any given target.
const char *Name;
/// The bit offset to write the relocation into.
//
// FIXME: These two fields are under-specified and not general enough, but it
// is covers many things, and is enough to let the AsmStreamer pretty-print
// the encoding.
unsigned TargetOffset;
/// The number of bits written by this fixup. The bits are assumed to be
/// contiguous.
unsigned TargetSize;
/// Flags describing additional information on this fixup kind.
unsigned Flags;
};
/// MCCodeEmitter - Generic instruction encoding interface.
class MCCodeEmitter {
private:
MCCodeEmitter(const MCCodeEmitter &); // DO NOT IMPLEMENT
void operator=(const MCCodeEmitter &); // DO NOT IMPLEMENT
protected: // Can only create subclasses.
MCCodeEmitter();
public:
virtual ~MCCodeEmitter();
/// @name Target Independent Fixup Information
/// @{
/// getNumFixupKinds - Get the number of target specific fixup kinds.
virtual unsigned getNumFixupKinds() const = 0;
/// getFixupKindInfo - Get information on a fixup kind.
virtual const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const;
/// @}
/// EncodeInstruction - Encode the given \arg Inst to bytes on the output
/// stream \arg OS.
virtual void EncodeInstruction(const MCInst &Inst, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const = 0;
};
} // End llvm namespace
#endif