llvm.org GIT mirror llvm / 637d89f include / llvm / MC / MCExpr.h
637d89f

Tree @637d89f (Download .tar.gz)

MCExpr.h @637d89fraw · history · blame

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
//===- MCExpr.h - Assembly Level Expressions --------------------*- 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_MCEXPR_H
#define LLVM_MC_MCEXPR_H

#include "llvm/Support/Casting.h"
#include "llvm/System/DataTypes.h"

namespace llvm {
class MCAsmInfo;
class MCAsmLayout;
class MCContext;
class MCSymbol;
class MCValue;
class raw_ostream;
class StringRef;

/// MCExpr - Base class for the full range of assembler expressions which are
/// needed for parsing.
class MCExpr {
public:
  enum ExprKind {
    Binary,    ///< Binary expressions.
    Constant,  ///< Constant expressions.
    SymbolRef, ///< References to labels and assigned expressions.
    Unary,     ///< Unary expressions.
    Target     ///< Target specific expression.
  };

private:
  ExprKind Kind;

  MCExpr(const MCExpr&); // DO NOT IMPLEMENT
  void operator=(const MCExpr&); // DO NOT IMPLEMENT

protected:
  explicit MCExpr(ExprKind _Kind) : Kind(_Kind) {}

public:
  /// @name Accessors
  /// @{

  ExprKind getKind() const { return Kind; }

  /// @}
  /// @name Utility Methods
  /// @{

  void print(raw_ostream &OS) const;
  void dump() const;

  /// @}
  /// @name Expression Evaluation
  /// @{

  /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
  ///
  /// @param Res - The absolute value, if evaluation succeeds.
  /// @param Layout - The assembler layout object to use for evaluating symbol
  /// values. If not given, then only non-symbolic expressions will be
  /// evaluated.
  /// @result - True on success.
  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout = 0) 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.
  /// @param Layout - The assembler layout object to use for evaluating values.
  /// @result - True on success.
  bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout = 0) const;

  /// @}

  static bool classof(const MCExpr *) { return true; }
};

inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
  E.print(OS);
  return OS;
}

//// MCConstantExpr - Represent a constant integer expression.
class MCConstantExpr : public MCExpr {
  int64_t Value;

  explicit MCConstantExpr(int64_t _Value)
    : MCExpr(MCExpr::Constant), Value(_Value) {}

public:
  /// @name Construction
  /// @{

  static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);

  /// @}
  /// @name Accessors
  /// @{

  int64_t getValue() const { return Value; }

  /// @}

  static bool classof(const MCExpr *E) {
    return E->getKind() == MCExpr::Constant;
  }
  static bool classof(const MCConstantExpr *) { return true; }
};

/// MCSymbolRefExpr - 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 MCSymbolRefExpr : public MCExpr {
public:
  enum VariantKind {
    VK_None,
    VK_Invalid,

    VK_GOT,
    VK_GOTOFF,
    VK_GOTPCREL,
    VK_GOTTPOFF,
    VK_INDNTPOFF,
    VK_NTPOFF,
    VK_PLT,
    VK_TLSGD,
    VK_TPOFF,
    VK_ARM_HI16, // The R_ARM_MOVT_ABS relocation (:upper16: in the asm file)
    VK_ARM_LO16, // The R_ARM_MOVW_ABS_NC relocation (:lower16: in the asm file)
    VK_ARM_PLT,  // ARM-style PLT symbol references. i.e., (PLT) instead of @PLT
    VK_TLVP // Mach-O thread local variable relocation
  };

private:
  /// The symbol being referenced.
  const MCSymbol *Symbol;

  /// The symbol reference modifier.
  const VariantKind Kind;

  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {}

public:
  /// @name Construction
  /// @{

  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
  }

  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
                                       MCContext &Ctx);
  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
                                       MCContext &Ctx);
  
  /// @}
  /// @name Accessors
  /// @{

  const MCSymbol &getSymbol() const { return *Symbol; }

  VariantKind getKind() const { return Kind; }

  /// @}
  /// @name Static Utility Functions
  /// @{

  static StringRef getVariantKindName(VariantKind Kind);

  static VariantKind getVariantKindForName(StringRef Name);

  /// @}

  static bool classof(const MCExpr *E) {
    return E->getKind() == MCExpr::SymbolRef;
  }
  static bool classof(const MCSymbolRefExpr *) { return true; }
};

/// MCUnaryExpr - Unary assembler expressions.
class MCUnaryExpr : public MCExpr {
public:
  enum Opcode {
    LNot,  ///< Logical negation.
    Minus, ///< Unary minus.
    Not,   ///< Bitwise negation.
    Plus   ///< Unary plus.
  };

private:
  Opcode Op;
  const MCExpr *Expr;

  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}

public:
  /// @name Construction
  /// @{

  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
                                   MCContext &Ctx);
  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
    return Create(LNot, Expr, Ctx);
  }
  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
    return Create(Minus, Expr, Ctx);
  }
  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
    return Create(Not, Expr, Ctx);
  }
  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
    return Create(Plus, Expr, Ctx);
  }

  /// @}
  /// @name Accessors
  /// @{

  /// getOpcode - Get the kind of this unary expression.
  Opcode getOpcode() const { return Op; }

  /// getSubExpr - Get the child of this unary expression.
  const MCExpr *getSubExpr() const { return Expr; }

  /// @}

  static bool classof(const MCExpr *E) {
    return E->getKind() == MCExpr::Unary;
  }
  static bool classof(const MCUnaryExpr *) { return true; }
};

/// MCBinaryExpr - Binary assembler expressions.
class MCBinaryExpr : public MCExpr {
public:
  enum Opcode {
    Add,  ///< Addition.
    And,  ///< Bitwise and.
    Div,  ///< Signed division.
    EQ,   ///< Equality comparison.
    GT,   ///< Signed greater than comparison (result is either 0 or some
          ///< target-specific non-zero value)
    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
          ///< some target-specific non-zero value).
    LAnd, ///< Logical and.
    LOr,  ///< Logical or.
    LT,   ///< Signed less than comparison (result is either 0 or
          ///< some target-specific non-zero value).
    LTE,  ///< Signed less than or equal comparison (result is either 0 or
          ///< some target-specific non-zero value).
    Mod,  ///< Signed remainder.
    Mul,  ///< Multiplication.
    NE,   ///< Inequality comparison.
    Or,   ///< Bitwise or.
    Shl,  ///< Shift left.
    Shr,  ///< Shift right (arithmetic or logical, depending on target)
    Sub,  ///< Subtraction.
    Xor   ///< Bitwise exclusive or.
  };

private:
  Opcode Op;
  const MCExpr *LHS, *RHS;

  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}

public:
  /// @name Construction
  /// @{

  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
                                    const MCExpr *RHS, MCContext &Ctx);
  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Add, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(And, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Div, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
                                      MCContext &Ctx) {
    return Create(EQ, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
                                      MCContext &Ctx) {
    return Create(GT, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(GTE, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
                                        MCContext &Ctx) {
    return Create(LAnd, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(LOr, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
                                      MCContext &Ctx) {
    return Create(LT, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(LTE, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Mod, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Mul, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
                                      MCContext &Ctx) {
    return Create(NE, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
                                      MCContext &Ctx) {
    return Create(Or, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Shl, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Shr, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Sub, LHS, RHS, Ctx);
  }
  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
                                       MCContext &Ctx) {
    return Create(Xor, LHS, RHS, Ctx);
  }

  /// @}
  /// @name Accessors
  /// @{

  /// getOpcode - Get the kind of this binary expression.
  Opcode getOpcode() const { return Op; }

  /// getLHS - Get the left-hand side expression of the binary operator.
  const MCExpr *getLHS() const { return LHS; }

  /// getRHS - Get the right-hand side expression of the binary operator.
  const MCExpr *getRHS() const { return RHS; }

  /// @}

  static bool classof(const MCExpr *E) {
    return E->getKind() == MCExpr::Binary;
  }
  static bool classof(const MCBinaryExpr *) { return true; }
};

/// MCTargetExpr - This is an extension point for target-specific MCExpr
/// subclasses to implement.
///
/// NOTE: All subclasses are required to have trivial destructors because
/// MCExprs are bump pointer allocated and not destructed.
class MCTargetExpr : public MCExpr {
  virtual void Anchor();
protected:
  MCTargetExpr() : MCExpr(Target) {}
  virtual ~MCTargetExpr() {}
public:

  virtual void PrintImpl(raw_ostream &OS) const = 0;
  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
                                         const MCAsmLayout *Layout) const = 0;


  static bool classof(const MCExpr *E) {
    return E->getKind() == MCExpr::Target;
  }
  static bool classof(const MCTargetExpr *) { return true; }
};

} // end namespace llvm

#endif