MCExpr.h revision 12cfa119600418d31ceb748d077b3e6f7057a22a 
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/ADT/DenseMap.h"
14#include "llvm/Support/Casting.h"
15#include "llvm/Support/DataTypes.h"
16
17namespace llvm {
18class MCAsmLayout;
19class MCAssembler;
20class MCContext;
21class MCSection;
22class MCSectionData;
23class MCSymbol;
24class MCValue;
25class raw_ostream;
26class StringRef;
27typedef DenseMap<const MCSectionData*, uint64_t> SectionAddrMap;
28
29/// MCExpr - Base class for the full range of assembler expressions which are
30/// needed for parsing.
31class MCExpr {
32public:
33  enum ExprKind {
34    Binary,    ///< Binary expressions.
35    Constant,  ///< Constant expressions.
36    SymbolRef, ///< References to labels and assigned expressions.
37    Unary,     ///< Unary expressions.
38    Target     ///< Target specific expression.
39  };
40
41private:
42  ExprKind Kind;
43
44  MCExpr(const MCExpr&) LLVM_DELETED_FUNCTION;
45  void operator=(const MCExpr&) LLVM_DELETED_FUNCTION;
46
47  bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
48                          const MCAsmLayout *Layout,
49                          const SectionAddrMap *Addrs) const;
50protected:
51  explicit MCExpr(ExprKind _Kind) : Kind(_Kind) {}
52
53  bool EvaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
54                                 const MCAsmLayout *Layout,
55                                 const SectionAddrMap *Addrs,
56                                 bool InSet) const;
57public:
58  /// @name Accessors
59  /// @{
60
61  ExprKind getKind() const { return Kind; }
62
63  /// @}
64  /// @name Utility Methods
65  /// @{
66
67  void print(raw_ostream &OS) const;
68  void dump() const;
69
70  /// @}
71  /// @name Expression Evaluation
72  /// @{
73
74  /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
75  ///
76  /// @param Res - The absolute value, if evaluation succeeds.
77  /// @param Layout - The assembler layout object to use for evaluating symbol
78  /// values. If not given, then only non-symbolic expressions will be
79  /// evaluated.
80  /// @result - True on success.
81  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
82                          const SectionAddrMap &Addrs) const;
83  bool EvaluateAsAbsolute(int64_t &Res) const;
84  bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
85  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
86
87  /// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
88  /// value, i.e. an expression of the fixed form (a - b + constant).
89  ///
90  /// @param Res - The relocatable value, if evaluation succeeds.
91  /// @param Layout - The assembler layout object to use for evaluating values.
92  /// @result - True on success.
93  bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout &Layout) const;
94
95  /// FindAssociatedSection - Find the "associated section" for this expression,
96  /// which is currently defined as the absolute section for constants, or
97  /// otherwise the section associated with the first defined symbol in the
98  /// expression.
99  const MCSection *FindAssociatedSection() const;
100
101  /// @}
102};
103
104inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
105  E.print(OS);
106  return OS;
107}
108
109//// MCConstantExpr - Represent a constant integer expression.
110class MCConstantExpr : public MCExpr {
111  int64_t Value;
112
113  explicit MCConstantExpr(int64_t _Value)
114    : MCExpr(MCExpr::Constant), Value(_Value) {}
115
116public:
117  /// @name Construction
118  /// @{
119
120  static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
121
122  /// @}
123  /// @name Accessors
124  /// @{
125
126  int64_t getValue() const { return Value; }
127
128  /// @}
129
130  static bool classof(const MCExpr *E) {
131    return E->getKind() == MCExpr::Constant;
132  }
133};
134
135/// MCSymbolRefExpr - Represent a reference to a symbol from inside an
136/// expression.
137///
138/// A symbol reference in an expression may be a use of a label, a use of an
139/// assembler variable (defined constant), or constitute an implicit definition
140/// of the symbol as external.
141class MCSymbolRefExpr : public MCExpr {
142public:
143  enum VariantKind {
144    VK_None,
145    VK_Invalid,
146
147    VK_GOT,
148    VK_GOTOFF,
149    VK_GOTPCREL,
150    VK_GOTTPOFF,
151    VK_INDNTPOFF,
152    VK_NTPOFF,
153    VK_GOTNTPOFF,
154    VK_PLT,
155    VK_TLSGD,
156    VK_TLSLD,
157    VK_TLSLDM,
158    VK_TPOFF,
159    VK_DTPOFF,
160    VK_TLVP,      // Mach-O thread local variable relocation
161    VK_SECREL,
162    // FIXME: We'd really like to use the generic Kinds listed above for these.
163    VK_ARM_PLT,   // ARM-style PLT references. i.e., (PLT) instead of @PLT
164    VK_ARM_TLSGD, //   ditto for TLSGD, GOT, GOTOFF, TPOFF and GOTTPOFF
165    VK_ARM_GOT,
166    VK_ARM_GOTOFF,
167    VK_ARM_TPOFF,
168    VK_ARM_GOTTPOFF,
169    VK_ARM_TARGET1,
170    VK_ARM_TARGET2,
171
172    VK_PPC_TOC,          // TOC base
173    VK_PPC_TOC_ENTRY,    // TOC entry
174    VK_PPC_DARWIN_HA16,  // ha16(symbol)
175    VK_PPC_DARWIN_LO16,  // lo16(symbol)
176    VK_PPC_GAS_HA16,     // symbol@ha
177    VK_PPC_GAS_LO16,      // symbol@l
178    VK_PPC_TPREL16_HA,   // symbol@tprel@ha
179    VK_PPC_TPREL16_LO,   // symbol@tprel@l
180
181    VK_Mips_GPREL,
182    VK_Mips_GOT_CALL,
183    VK_Mips_GOT16,
184    VK_Mips_GOT,
185    VK_Mips_ABS_HI,
186    VK_Mips_ABS_LO,
187    VK_Mips_TLSGD,
188    VK_Mips_TLSLDM,
189    VK_Mips_DTPREL_HI,
190    VK_Mips_DTPREL_LO,
191    VK_Mips_GOTTPREL,
192    VK_Mips_TPREL_HI,
193    VK_Mips_TPREL_LO,
194    VK_Mips_GPOFF_HI,
195    VK_Mips_GPOFF_LO,
196    VK_Mips_GOT_DISP,
197    VK_Mips_GOT_PAGE,
198    VK_Mips_GOT_OFST,
199    VK_Mips_HIGHER,
200    VK_Mips_HIGHEST
201  };
202
203private:
204  /// The symbol being referenced.
205  const MCSymbol *Symbol;
206
207  /// The symbol reference modifier.
208  const VariantKind Kind;
209
210  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
211    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
212    assert(Symbol);
213  }
214
215public:
216  /// @name Construction
217  /// @{
218
219  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
220    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
221  }
222
223  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
224                                       MCContext &Ctx);
225  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
226                                       MCContext &Ctx);
227
228  /// @}
229  /// @name Accessors
230  /// @{
231
232  const MCSymbol &getSymbol() const { return *Symbol; }
233
234  VariantKind getKind() const { return Kind; }
235
236  /// @}
237  /// @name Static Utility Functions
238  /// @{
239
240  static StringRef getVariantKindName(VariantKind Kind);
241
242  static VariantKind getVariantKindForName(StringRef Name);
243
244  /// @}
245
246  static bool classof(const MCExpr *E) {
247    return E->getKind() == MCExpr::SymbolRef;
248  }
249};
250
251/// MCUnaryExpr - Unary assembler expressions.
252class MCUnaryExpr : public MCExpr {
253public:
254  enum Opcode {
255    LNot,  ///< Logical negation.
256    Minus, ///< Unary minus.
257    Not,   ///< Bitwise negation.
258    Plus   ///< Unary plus.
259  };
260
261private:
262  Opcode Op;
263  const MCExpr *Expr;
264
265  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
266    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
267
268public:
269  /// @name Construction
270  /// @{
271
272  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
273                                   MCContext &Ctx);
274  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
275    return Create(LNot, Expr, Ctx);
276  }
277  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
278    return Create(Minus, Expr, Ctx);
279  }
280  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
281    return Create(Not, Expr, Ctx);
282  }
283  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
284    return Create(Plus, Expr, Ctx);
285  }
286
287  /// @}
288  /// @name Accessors
289  /// @{
290
291  /// getOpcode - Get the kind of this unary expression.
292  Opcode getOpcode() const { return Op; }
293
294  /// getSubExpr - Get the child of this unary expression.
295  const MCExpr *getSubExpr() const { return Expr; }
296
297  /// @}
298
299  static bool classof(const MCExpr *E) {
300    return E->getKind() == MCExpr::Unary;
301  }
302};
303
304/// MCBinaryExpr - Binary assembler expressions.
305class MCBinaryExpr : public MCExpr {
306public:
307  enum Opcode {
308    Add,  ///< Addition.
309    And,  ///< Bitwise and.
310    Div,  ///< Signed division.
311    EQ,   ///< Equality comparison.
312    GT,   ///< Signed greater than comparison (result is either 0 or some
313          ///< target-specific non-zero value)
314    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
315          ///< some target-specific non-zero value).
316    LAnd, ///< Logical and.
317    LOr,  ///< Logical or.
318    LT,   ///< Signed less than comparison (result is either 0 or
319          ///< some target-specific non-zero value).
320    LTE,  ///< Signed less than or equal comparison (result is either 0 or
321          ///< some target-specific non-zero value).
322    Mod,  ///< Signed remainder.
323    Mul,  ///< Multiplication.
324    NE,   ///< Inequality comparison.
325    Or,   ///< Bitwise or.
326    Shl,  ///< Shift left.
327    Shr,  ///< Shift right (arithmetic or logical, depending on target)
328    Sub,  ///< Subtraction.
329    Xor   ///< Bitwise exclusive or.
330  };
331
332private:
333  Opcode Op;
334  const MCExpr *LHS, *RHS;
335
336  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
337    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
338
339public:
340  /// @name Construction
341  /// @{
342
343  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
344                                    const MCExpr *RHS, MCContext &Ctx);
345  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
346                                       MCContext &Ctx) {
347    return Create(Add, LHS, RHS, Ctx);
348  }
349  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
350                                       MCContext &Ctx) {
351    return Create(And, LHS, RHS, Ctx);
352  }
353  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
354                                       MCContext &Ctx) {
355    return Create(Div, LHS, RHS, Ctx);
356  }
357  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
358                                      MCContext &Ctx) {
359    return Create(EQ, LHS, RHS, Ctx);
360  }
361  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
362                                      MCContext &Ctx) {
363    return Create(GT, LHS, RHS, Ctx);
364  }
365  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
366                                       MCContext &Ctx) {
367    return Create(GTE, LHS, RHS, Ctx);
368  }
369  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
370                                        MCContext &Ctx) {
371    return Create(LAnd, LHS, RHS, Ctx);
372  }
373  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
374                                       MCContext &Ctx) {
375    return Create(LOr, LHS, RHS, Ctx);
376  }
377  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
378                                      MCContext &Ctx) {
379    return Create(LT, LHS, RHS, Ctx);
380  }
381  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
382                                       MCContext &Ctx) {
383    return Create(LTE, LHS, RHS, Ctx);
384  }
385  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
386                                       MCContext &Ctx) {
387    return Create(Mod, LHS, RHS, Ctx);
388  }
389  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
390                                       MCContext &Ctx) {
391    return Create(Mul, LHS, RHS, Ctx);
392  }
393  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
394                                      MCContext &Ctx) {
395    return Create(NE, LHS, RHS, Ctx);
396  }
397  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
398                                      MCContext &Ctx) {
399    return Create(Or, LHS, RHS, Ctx);
400  }
401  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
402                                       MCContext &Ctx) {
403    return Create(Shl, LHS, RHS, Ctx);
404  }
405  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
406                                       MCContext &Ctx) {
407    return Create(Shr, LHS, RHS, Ctx);
408  }
409  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
410                                       MCContext &Ctx) {
411    return Create(Sub, LHS, RHS, Ctx);
412  }
413  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
414                                       MCContext &Ctx) {
415    return Create(Xor, LHS, RHS, Ctx);
416  }
417
418  /// @}
419  /// @name Accessors
420  /// @{
421
422  /// getOpcode - Get the kind of this binary expression.
423  Opcode getOpcode() const { return Op; }
424
425  /// getLHS - Get the left-hand side expression of the binary operator.
426  const MCExpr *getLHS() const { return LHS; }
427
428  /// getRHS - Get the right-hand side expression of the binary operator.
429  const MCExpr *getRHS() const { return RHS; }
430
431  /// @}
432
433  static bool classof(const MCExpr *E) {
434    return E->getKind() == MCExpr::Binary;
435  }
436};
437
438/// MCTargetExpr - This is an extension point for target-specific MCExpr
439/// subclasses to implement.
440///
441/// NOTE: All subclasses are required to have trivial destructors because
442/// MCExprs are bump pointer allocated and not destructed.
443class MCTargetExpr : public MCExpr {
444  virtual void anchor();
445protected:
446  MCTargetExpr() : MCExpr(Target) {}
447  virtual ~MCTargetExpr() {}
448public:
449
450  virtual void PrintImpl(raw_ostream &OS) const = 0;
451  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
452                                         const MCAsmLayout *Layout) const = 0;
453  virtual void AddValueSymbols(MCAssembler *) const = 0;
454  virtual const MCSection *FindAssociatedSection() const = 0;
455
456  static bool classof(const MCExpr *E) {
457    return E->getKind() == MCExpr::Target;
458  }
459};
460
461} // end namespace llvm
462
463#endif
464