freebsd-dev/include/llvm/MC/MCValue.h
2009-10-14 17:57:32 +00:00

86 lines
2.5 KiB
C++

//===-- llvm/MC/MCValue.h - MCValue 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 MCValue class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCVALUE_H
#define LLVM_MC_MCVALUE_H
#include "llvm/Support/DataTypes.h"
#include "llvm/MC/MCSymbol.h"
#include <cassert>
namespace llvm {
class MCSymbol;
class raw_ostream;
/// MCValue - This represents an "assembler immediate". In its most general
/// form, this can hold "SymbolA - SymbolB + imm64". Not all targets supports
/// relocations of this general form, but we need to represent this anyway.
///
/// In the general form, SymbolB can only be defined if SymbolA is, and both
/// must be in the same (non-external) section. The latter constraint is not
/// enforced, since a symbol's section may not be known at construction.
///
/// Note that this class must remain a simple POD value class, because we need
/// it to live in unions etc.
class MCValue {
const MCSymbol *SymA, *SymB;
int64_t Cst;
public:
int64_t getConstant() const { return Cst; }
const MCSymbol *getSymA() const { return SymA; }
const MCSymbol *getSymB() const { return SymB; }
/// isAbsolute - Is this an absolute (as opposed to relocatable) value.
bool isAbsolute() const { return !SymA && !SymB; }
/// getAssociatedSection - For relocatable values, return the section the
/// value is associated with.
///
/// @result - The value's associated section, or null for external or constant
/// values.
//
// FIXME: Switch to a tagged section, so this can return the tagged section
// value.
const MCSection *getAssociatedSection() const;
/// print - Print the value to the stream \arg OS.
void print(raw_ostream &OS, const MCAsmInfo *MAI) const;
/// dump - Print the value to stderr.
void dump() const;
static MCValue get(const MCSymbol *SymA, const MCSymbol *SymB = 0,
int64_t Val = 0) {
MCValue R;
assert((!SymB || SymA) && "Invalid relocatable MCValue!");
R.Cst = Val;
R.SymA = SymA;
R.SymB = SymB;
return R;
}
static MCValue get(int64_t Val) {
MCValue R;
R.Cst = Val;
R.SymA = 0;
R.SymB = 0;
return R;
}
};
} // end namespace llvm
#endif