MCExpr.h revision 684c593d05db0bd277268fc9d8c05bce138c745a 
1//===- MCExpr.h - Assembly Level Expressions --------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LLVM_MC_MCEXPR_H
11#define LLVM_MC_MCEXPR_H
12
13#include "llvm/Support/Casting.h"
14#include "llvm/Support/DataTypes.h"
15
16namespace llvm {
17class MCAsmInfo;
18class MCContext;
19class MCSymbol;
20class MCValue;
21class raw_ostream;
22
23/// MCExpr - Base class for the full range of assembler expressions which are
24/// needed for parsing.
25class MCExpr {
26public:
27  enum ExprKind {
28    Binary,    ///< Binary expressions.
29    Constant,  ///< Constant expressions.
30    SymbolRef, ///< References to labels and assigned expressions.
31    Unary      ///< Unary expressions.
32  };
33
34private:
35  ExprKind Kind;
36
37  MCExpr(const MCExpr&); // DO NOT IMPLEMENT
38  void operator=(const MCExpr&); // DO NOT IMPLEMENT
39
40protected:
41  MCExpr(ExprKind _Kind) : Kind(_Kind) {}
42
43public:
44  /// @name Accessors
45  /// @{
46
47  ExprKind getKind() const { return Kind; }
48
49  /// @}
50  /// @name Utility Methods
51  /// @{
52
53  void print(raw_ostream &OS, const MCAsmInfo *MAI) const;
54  void dump() const;
55
56  /// @}
57  /// @name Expression Evaluation
58  /// @{
59
60  /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
61  ///
62  /// @param Res - The absolute value, if evaluation succeeds.
63  /// @result - True on success.
64  bool EvaluateAsAbsolute(MCContext &Ctx, int64_t &Res) const;
65
66  /// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
67  /// value, i.e. an expression of the fixed form (a - b + constant).
68  ///
69  /// @param Res - The relocatable value, if evaluation succeeds.
70  /// @result - True on success.
71  bool EvaluateAsRelocatable(MCContext &Ctx, MCValue &Res) const;
72
73  /// @}
74
75  static bool classof(const MCExpr *) { return true; }
76};
77
78//// MCConstantExpr - Represent a constant integer expression.
79class MCConstantExpr : public MCExpr {
80  int64_t Value;
81
82  MCConstantExpr(int64_t _Value)
83    : MCExpr(MCExpr::Constant), Value(_Value) {}
84
85public:
86  /// @name Construction
87  /// @{
88
89  static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
90
91  /// @}
92  /// @name Accessors
93  /// @{
94
95  int64_t getValue() const { return Value; }
96
97  /// @}
98
99  static bool classof(const MCExpr *E) {
100    return E->getKind() == MCExpr::Constant;
101  }
102  static bool classof(const MCConstantExpr *) { return true; }
103};
104
105/// MCSymbolRefExpr - Represent a reference to a symbol from inside an
106/// expression.
107///
108/// A symbol reference in an expression may be a use of a label, a use of an
109/// assembler variable (defined constant), or constitute an implicit definition
110/// of the symbol as external.
111class MCSymbolRefExpr : public MCExpr {
112  const MCSymbol *Symbol;
113
114  MCSymbolRefExpr(const MCSymbol *_Symbol)
115    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol) {}
116
117public:
118  /// @name Construction
119  /// @{
120
121  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx);
122
123  /// @}
124  /// @name Accessors
125  /// @{
126
127  const MCSymbol &getSymbol() const { return *Symbol; }
128
129  /// @}
130
131  static bool classof(const MCExpr *E) {
132    return E->getKind() == MCExpr::SymbolRef;
133  }
134  static bool classof(const MCSymbolRefExpr *) { return true; }
135};
136
137/// MCUnaryExpr - Unary assembler expressions.
138class MCUnaryExpr : public MCExpr {
139public:
140  enum Opcode {
141    LNot,  ///< Logical negation.
142    Minus, ///< Unary minus.
143    Not,   ///< Bitwise negation.
144    Plus   ///< Unary plus.
145  };
146
147private:
148  Opcode Op;
149  const MCExpr *Expr;
150
151  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
152    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
153
154public:
155  /// @name Construction
156  /// @{
157
158  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
159                                   MCContext &Ctx);
160  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
161    return Create(LNot, Expr, Ctx);
162  }
163  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
164    return Create(Minus, Expr, Ctx);
165  }
166  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
167    return Create(Not, Expr, Ctx);
168  }
169  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
170    return Create(Plus, Expr, Ctx);
171  }
172
173  /// @}
174  /// @name Accessors
175  /// @{
176
177  /// getOpcode - Get the kind of this unary expression.
178  Opcode getOpcode() const { return Op; }
179
180  /// getSubExpr - Get the child of this unary expression.
181  const MCExpr *getSubExpr() const { return Expr; }
182
183  /// @}
184
185  static bool classof(const MCExpr *E) {
186    return E->getKind() == MCExpr::Unary;
187  }
188  static bool classof(const MCUnaryExpr *) { return true; }
189};
190
191/// MCBinaryExpr - Binary assembler expressions.
192class MCBinaryExpr : public MCExpr {
193public:
194  enum Opcode {
195    Add,  ///< Addition.
196    And,  ///< Bitwise and.
197    Div,  ///< Division.
198    EQ,   ///< Equality comparison.
199    GT,   ///< Greater than comparison.
200    GTE,  ///< Greater than or equal comparison.
201    LAnd, ///< Logical and.
202    LOr,  ///< Logical or.
203    LT,   ///< Less than comparison.
204    LTE,  ///< Less than or equal comparison.
205    Mod,  ///< Modulus.
206    Mul,  ///< Multiplication.
207    NE,   ///< Inequality comparison.
208    Or,   ///< Bitwise or.
209    Shl,  ///< Bitwise shift left.
210    Shr,  ///< Bitwise shift right.
211    Sub,  ///< Subtraction.
212    Xor   ///< Bitwise exclusive or.
213  };
214
215private:
216  Opcode Op;
217  const MCExpr *LHS, *RHS;
218
219  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
220    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
221
222public:
223  /// @name Construction
224  /// @{
225
226  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
227                                    const MCExpr *RHS, MCContext &Ctx);
228  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
229                                       MCContext &Ctx) {
230    return Create(Add, LHS, RHS, Ctx);
231  }
232  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
233                                       MCContext &Ctx) {
234    return Create(And, LHS, RHS, Ctx);
235  }
236  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
237                                       MCContext &Ctx) {
238    return Create(Div, LHS, RHS, Ctx);
239  }
240  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
241                                      MCContext &Ctx) {
242    return Create(EQ, LHS, RHS, Ctx);
243  }
244  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
245                                      MCContext &Ctx) {
246    return Create(GT, LHS, RHS, Ctx);
247  }
248  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
249                                       MCContext &Ctx) {
250    return Create(GTE, LHS, RHS, Ctx);
251  }
252  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
253                                        MCContext &Ctx) {
254    return Create(LAnd, LHS, RHS, Ctx);
255  }
256  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
257                                       MCContext &Ctx) {
258    return Create(LOr, LHS, RHS, Ctx);
259  }
260  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
261                                      MCContext &Ctx) {
262    return Create(LT, LHS, RHS, Ctx);
263  }
264  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
265                                       MCContext &Ctx) {
266    return Create(LTE, LHS, RHS, Ctx);
267  }
268  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
269                                       MCContext &Ctx) {
270    return Create(Mod, LHS, RHS, Ctx);
271  }
272  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
273                                       MCContext &Ctx) {
274    return Create(Mul, LHS, RHS, Ctx);
275  }
276  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
277                                      MCContext &Ctx) {
278    return Create(NE, LHS, RHS, Ctx);
279  }
280  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
281                                      MCContext &Ctx) {
282    return Create(Or, LHS, RHS, Ctx);
283  }
284  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
285                                       MCContext &Ctx) {
286    return Create(Shl, LHS, RHS, Ctx);
287  }
288  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
289                                       MCContext &Ctx) {
290    return Create(Shr, LHS, RHS, Ctx);
291  }
292  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
293                                       MCContext &Ctx) {
294    return Create(Sub, LHS, RHS, Ctx);
295  }
296  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
297                                       MCContext &Ctx) {
298    return Create(Xor, LHS, RHS, Ctx);
299  }
300
301  /// @}
302  /// @name Accessors
303  /// @{
304
305  /// getOpcode - Get the kind of this binary expression.
306  Opcode getOpcode() const { return Op; }
307
308  /// getLHS - Get the left-hand side expression of the binary operator.
309  const MCExpr *getLHS() const { return LHS; }
310
311  /// getRHS - Get the right-hand side expression of the binary operator.
312  const MCExpr *getRHS() const { return RHS; }
313
314  /// @}
315
316  static bool classof(const MCExpr *E) {
317    return E->getKind() == MCExpr::Binary;
318  }
319  static bool classof(const MCBinaryExpr *) { return true; }
320};
321
322} // end namespace llvm
323
324#endif
325