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

86 lines
3.4 KiB
C++

//===-- llvm/MC/MCSymbolizer.h - MCSymbolizer class -------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the MCSymbolizer class, which is used
// to symbolize instructions decoded from an object, that is, transform their
// immediate operands to MCExprs.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCSYMBOLIZER_H
#define LLVM_MC_MCSYMBOLIZER_H
#include "llvm/MC/MCRelocationInfo.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/DataTypes.h"
#include <cassert>
#include <memory>
namespace llvm {
class MCContext;
class MCInst;
class raw_ostream;
/// \brief Symbolize and annotate disassembled instructions.
///
/// For now this mimics the old symbolization logic (from both ARM and x86), that
/// relied on user-provided (C API) callbacks to do the actual symbol lookup in
/// the object file. This was moved to MCExternalSymbolizer.
/// A better API would not rely on actually calling the two methods here from
/// inside each disassembler, but would use the instr info to determine what
/// operands are actually symbolizable, and in what way. I don't think this
/// information exists right now.
class MCSymbolizer {
MCSymbolizer(const MCSymbolizer &) = delete;
void operator=(const MCSymbolizer &) = delete;
protected:
MCContext &Ctx;
std::unique_ptr<MCRelocationInfo> RelInfo;
public:
/// \brief Construct an MCSymbolizer, taking ownership of \p RelInfo.
MCSymbolizer(MCContext &Ctx, std::unique_ptr<MCRelocationInfo> RelInfo)
: Ctx(Ctx), RelInfo(std::move(RelInfo)) {
}
virtual ~MCSymbolizer();
/// \brief Try to add a symbolic operand instead of \p Value to the MCInst.
///
/// Instead of having a difficult to read immediate, a symbolic operand would
/// represent this immediate in a more understandable way, for instance as a
/// symbol or an offset from a symbol. Relocations can also be used to enrich
/// the symbolic expression.
/// @param Inst - The MCInst where to insert the symbolic operand.
/// @param cStream - Stream to print comments and annotations on.
/// @param Value - Operand value, pc-adjusted by the caller if necessary.
/// @param Address - Load address of the instruction.
/// @param IsBranch - Is the instruction a branch?
/// @param Offset - Byte offset of the operand inside the inst.
/// @param InstSize - Size of the instruction in bytes.
/// @return Whether a symbolic operand was added.
virtual bool tryAddingSymbolicOperand(MCInst &Inst, raw_ostream &cStream,
int64_t Value, uint64_t Address,
bool IsBranch, uint64_t Offset,
uint64_t InstSize) = 0;
/// \brief Try to add a comment on the PC-relative load.
/// For instance, in Mach-O, this is used to add annotations to instructions
/// that use C string literals, as found in __cstring.
virtual void tryAddingPcLoadReferenceComment(raw_ostream &cStream,
int64_t Value,
uint64_t Address) = 0;
};
}
#endif