llvm-6502/tools/llvm-mc/AsmExpr.h
Daniel Dunbar 1aa14aac41 llvm-mc: Add some more doxyments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74607 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-01 15:14:50 +00:00

180 lines
4.7 KiB
C++

//===- AsmExpr.h - Assembly file expressions --------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef ASMEXPR_H
#define ASMEXPR_H
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
class MCContext;
class MCSymbol;
class MCValue;
/// AsmExpr - Base class for the full range of assembler expressions which are
/// needed for parsing.
class AsmExpr {
public:
enum AsmExprKind {
Binary, ///< Binary expressions.
Constant, ///< Constant expressions.
SymbolRef, ///< References to labels and assigned expressions.
Unary ///< Unary expressions.
};
private:
AsmExprKind Kind;
protected:
AsmExpr(AsmExprKind _Kind) : Kind(_Kind) {}
public:
virtual ~AsmExpr();
AsmExprKind getKind() const { return Kind; }
/// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
///
/// @param Res - The absolute value, if evaluation succeeds.
/// @result - True on success.
bool EvaluateAsAbsolute(MCContext &Ctx, int64_t &Res) const;
/// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
/// value, i.e. an expression of the fixed form (a - b + constant).
///
/// @param Res - The relocatable value, if evaluation succeeds.
/// @result - True on success.
bool EvaluateAsRelocatable(MCContext &Ctx, MCValue &Res) const;
static bool classof(const AsmExpr *) { return true; }
};
//// AsmConstantExpr - Represent a constant integer expression.
class AsmConstantExpr : public AsmExpr {
int64_t Value;
public:
AsmConstantExpr(int64_t _Value)
: AsmExpr(AsmExpr::Constant), Value(_Value) {}
int64_t getValue() const { return Value; }
static bool classof(const AsmExpr *E) {
return E->getKind() == AsmExpr::Constant;
}
static bool classof(const AsmConstantExpr *) { return true; }
};
/// AsmSymbolRefExpr - Represent a reference to a symbol from inside an
/// expression.
///
/// A symbol reference in an expression may be a use of a label, a use of an
/// assembler variable (defined constant), or constitute an implicit definition
/// of the symbol as external.
class AsmSymbolRefExpr : public AsmExpr {
MCSymbol *Symbol;
public:
AsmSymbolRefExpr(MCSymbol *_Symbol)
: AsmExpr(AsmExpr::SymbolRef), Symbol(_Symbol) {}
MCSymbol *getSymbol() const { return Symbol; }
static bool classof(const AsmExpr *E) {
return E->getKind() == AsmExpr::SymbolRef;
}
static bool classof(const AsmSymbolRefExpr *) { return true; }
};
/// AsmUnaryExpr - Unary assembler expressions.
class AsmUnaryExpr : public AsmExpr {
public:
enum Opcode {
LNot, ///< Logical negation.
Minus, ///< Unary minus.
Not, ///< Bitwise negation.
Plus ///< Unary plus.
};
private:
Opcode Op;
AsmExpr *Expr;
public:
AsmUnaryExpr(Opcode _Op, AsmExpr *_Expr)
: AsmExpr(AsmExpr::Unary), Op(_Op), Expr(_Expr) {}
~AsmUnaryExpr() {
delete Expr;
}
Opcode getOpcode() const { return Op; }
AsmExpr *getSubExpr() const { return Expr; }
static bool classof(const AsmExpr *E) {
return E->getKind() == AsmExpr::Unary;
}
static bool classof(const AsmUnaryExpr *) { return true; }
};
/// AsmBinaryExpr - Binary assembler expressions.
class AsmBinaryExpr : public AsmExpr {
public:
enum Opcode {
Add, ///< Addition.
And, ///< Bitwise and.
Div, ///< Division.
EQ, ///< Equality comparison.
GT, ///< Greater than comparison.
GTE, ///< Greater than or equal comparison.
LAnd, ///< Logical and.
LOr, ///< Logical or.
LT, ///< Less than comparison.
LTE, ///< Less than or equal comparison.
Mod, ///< Modulus.
Mul, ///< Multiplication.
NE, ///< Inequality comparison.
Or, ///< Bitwise or.
Shl, ///< Bitwise shift left.
Shr, ///< Bitwise shift right.
Sub, ///< Subtraction.
Xor ///< Bitwise exclusive or.
};
private:
Opcode Op;
AsmExpr *LHS, *RHS;
public:
AsmBinaryExpr(Opcode _Op, AsmExpr *_LHS, AsmExpr *_RHS)
: AsmExpr(AsmExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
~AsmBinaryExpr() {
delete LHS;
delete RHS;
}
Opcode getOpcode() const { return Op; }
/// getLHS - Get the left-hand side expression of the binary operator.
AsmExpr *getLHS() const { return LHS; }
/// getRHS - Get the right-hand side expression of the binary operator.
AsmExpr *getRHS() const { return RHS; }
static bool classof(const AsmExpr *E) {
return E->getKind() == AsmExpr::Binary;
}
static bool classof(const AsmBinaryExpr *) { return true; }
};
} // end namespace llvm
#endif