MCExpr.h revision 1f7210e808373fa92be3a2d4fa653a6f79d5088b 
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  static bool classof(const MCExpr *) { return true; }
104};
105
106inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
107  E.print(OS);
108  return OS;
109}
110
111//// MCConstantExpr - Represent a constant integer expression.
112class MCConstantExpr : public MCExpr {
113  int64_t Value;
114
115  explicit MCConstantExpr(int64_t _Value)
116    : MCExpr(MCExpr::Constant), Value(_Value) {}
117
118public:
119  /// @name Construction
120  /// @{
121
122  static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
123
124  /// @}
125  /// @name Accessors
126  /// @{
127
128  int64_t getValue() const { return Value; }
129
130  /// @}
131
132  static bool classof(const MCExpr *E) {
133    return E->getKind() == MCExpr::Constant;
134  }
135  static bool classof(const MCConstantExpr *) { return true; }
136};
137
138/// MCSymbolRefExpr - Represent a reference to a symbol from inside an
139/// expression.
140///
141/// A symbol reference in an expression may be a use of a label, a use of an
142/// assembler variable (defined constant), or constitute an implicit definition
143/// of the symbol as external.
144class MCSymbolRefExpr : public MCExpr {
145public:
146  enum VariantKind {
147    VK_None,
148    VK_Invalid,
149
150    VK_GOT,
151    VK_GOTOFF,
152    VK_GOTPCREL,
153    VK_GOTTPOFF,
154    VK_INDNTPOFF,
155    VK_NTPOFF,
156    VK_GOTNTPOFF,
157    VK_PLT,
158    VK_TLSGD,
159    VK_TLSLD,
160    VK_TLSLDM,
161    VK_TPOFF,
162    VK_DTPOFF,
163    VK_TLVP,      // Mach-O thread local variable relocation
164    VK_SECREL,
165    // FIXME: We'd really like to use the generic Kinds listed above for these.
166    VK_ARM_PLT,   // ARM-style PLT references. i.e., (PLT) instead of @PLT
167    VK_ARM_TLSGD, //   ditto for TLSGD, GOT, GOTOFF, TPOFF and GOTTPOFF
168    VK_ARM_GOT,
169    VK_ARM_GOTOFF,
170    VK_ARM_TPOFF,
171    VK_ARM_GOTTPOFF,
172    VK_ARM_TARGET1,
173
174    VK_PPC_TOC,          // TOC base
175    VK_PPC_TOC_ENTRY,    // TOC entry
176    VK_PPC_DARWIN_HA16,  // ha16(symbol)
177    VK_PPC_DARWIN_LO16,  // lo16(symbol)
178    VK_PPC_GAS_HA16,     // symbol@ha
179    VK_PPC_GAS_LO16,      // symbol@l
180    VK_PPC_TPREL16_HA,   // symbol@tprel@ha
181    VK_PPC_TPREL16_LO,   // symbol@tprel@l
182
183    VK_Mips_GPREL,
184    VK_Mips_GOT_CALL,
185    VK_Mips_GOT16,
186    VK_Mips_GOT,
187    VK_Mips_ABS_HI,
188    VK_Mips_ABS_LO,
189    VK_Mips_TLSGD,
190    VK_Mips_TLSLDM,
191    VK_Mips_DTPREL_HI,
192    VK_Mips_DTPREL_LO,
193    VK_Mips_GOTTPREL,
194    VK_Mips_TPREL_HI,
195    VK_Mips_TPREL_LO,
196    VK_Mips_GPOFF_HI,
197    VK_Mips_GPOFF_LO,
198    VK_Mips_GOT_DISP,
199    VK_Mips_GOT_PAGE,
200    VK_Mips_GOT_OFST,
201    VK_Mips_HIGHER,
202    VK_Mips_HIGHEST
203  };
204
205private:
206  /// The symbol being referenced.
207  const MCSymbol *Symbol;
208
209  /// The symbol reference modifier.
210  const VariantKind Kind;
211
212  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
213    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
214    assert(Symbol);
215  }
216
217public:
218  /// @name Construction
219  /// @{
220
221  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
222    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
223  }
224
225  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
226                                       MCContext &Ctx);
227  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
228                                       MCContext &Ctx);
229
230  /// @}
231  /// @name Accessors
232  /// @{
233
234  const MCSymbol &getSymbol() const { return *Symbol; }
235
236  VariantKind getKind() const { return Kind; }
237
238  /// @}
239  /// @name Static Utility Functions
240  /// @{
241
242  static StringRef getVariantKindName(VariantKind Kind);
243
244  static VariantKind getVariantKindForName(StringRef Name);
245
246  /// @}
247
248  static bool classof(const MCExpr *E) {
249    return E->getKind() == MCExpr::SymbolRef;
250  }
251  static bool classof(const MCSymbolRefExpr *) { return true; }
252};
253
254/// MCUnaryExpr - Unary assembler expressions.
255class MCUnaryExpr : public MCExpr {
256public:
257  enum Opcode {
258    LNot,  ///< Logical negation.
259    Minus, ///< Unary minus.
260    Not,   ///< Bitwise negation.
261    Plus   ///< Unary plus.
262  };
263
264private:
265  Opcode Op;
266  const MCExpr *Expr;
267
268  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
269    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
270
271public:
272  /// @name Construction
273  /// @{
274
275  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
276                                   MCContext &Ctx);
277  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
278    return Create(LNot, Expr, Ctx);
279  }
280  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
281    return Create(Minus, Expr, Ctx);
282  }
283  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
284    return Create(Not, Expr, Ctx);
285  }
286  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
287    return Create(Plus, Expr, Ctx);
288  }
289
290  /// @}
291  /// @name Accessors
292  /// @{
293
294  /// getOpcode - Get the kind of this unary expression.
295  Opcode getOpcode() const { return Op; }
296
297  /// getSubExpr - Get the child of this unary expression.
298  const MCExpr *getSubExpr() const { return Expr; }
299
300  /// @}
301
302  static bool classof(const MCExpr *E) {
303    return E->getKind() == MCExpr::Unary;
304  }
305  static bool classof(const MCUnaryExpr *) { return true; }
306};
307
308/// MCBinaryExpr - Binary assembler expressions.
309class MCBinaryExpr : public MCExpr {
310public:
311  enum Opcode {
312    Add,  ///< Addition.
313    And,  ///< Bitwise and.
314    Div,  ///< Signed division.
315    EQ,   ///< Equality comparison.
316    GT,   ///< Signed greater than comparison (result is either 0 or some
317          ///< target-specific non-zero value)
318    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
319          ///< some target-specific non-zero value).
320    LAnd, ///< Logical and.
321    LOr,  ///< Logical or.
322    LT,   ///< Signed less than comparison (result is either 0 or
323          ///< some target-specific non-zero value).
324    LTE,  ///< Signed less than or equal comparison (result is either 0 or
325          ///< some target-specific non-zero value).
326    Mod,  ///< Signed remainder.
327    Mul,  ///< Multiplication.
328    NE,   ///< Inequality comparison.
329    Or,   ///< Bitwise or.
330    Shl,  ///< Shift left.
331    Shr,  ///< Shift right (arithmetic or logical, depending on target)
332    Sub,  ///< Subtraction.
333    Xor   ///< Bitwise exclusive or.
334  };
335
336private:
337  Opcode Op;
338  const MCExpr *LHS, *RHS;
339
340  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
341    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
342
343public:
344  /// @name Construction
345  /// @{
346
347  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
348                                    const MCExpr *RHS, MCContext &Ctx);
349  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
350                                       MCContext &Ctx) {
351    return Create(Add, LHS, RHS, Ctx);
352  }
353  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
354                                       MCContext &Ctx) {
355    return Create(And, LHS, RHS, Ctx);
356  }
357  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
358                                       MCContext &Ctx) {
359    return Create(Div, LHS, RHS, Ctx);
360  }
361  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
362                                      MCContext &Ctx) {
363    return Create(EQ, LHS, RHS, Ctx);
364  }
365  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
366                                      MCContext &Ctx) {
367    return Create(GT, LHS, RHS, Ctx);
368  }
369  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
370                                       MCContext &Ctx) {
371    return Create(GTE, LHS, RHS, Ctx);
372  }
373  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
374                                        MCContext &Ctx) {
375    return Create(LAnd, LHS, RHS, Ctx);
376  }
377  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
378                                       MCContext &Ctx) {
379    return Create(LOr, LHS, RHS, Ctx);
380  }
381  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
382                                      MCContext &Ctx) {
383    return Create(LT, LHS, RHS, Ctx);
384  }
385  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
386                                       MCContext &Ctx) {
387    return Create(LTE, LHS, RHS, Ctx);
388  }
389  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
390                                       MCContext &Ctx) {
391    return Create(Mod, LHS, RHS, Ctx);
392  }
393  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
394                                       MCContext &Ctx) {
395    return Create(Mul, LHS, RHS, Ctx);
396  }
397  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
398                                      MCContext &Ctx) {
399    return Create(NE, LHS, RHS, Ctx);
400  }
401  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
402                                      MCContext &Ctx) {
403    return Create(Or, LHS, RHS, Ctx);
404  }
405  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
406                                       MCContext &Ctx) {
407    return Create(Shl, LHS, RHS, Ctx);
408  }
409  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
410                                       MCContext &Ctx) {
411    return Create(Shr, LHS, RHS, Ctx);
412  }
413  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
414                                       MCContext &Ctx) {
415    return Create(Sub, LHS, RHS, Ctx);
416  }
417  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
418                                       MCContext &Ctx) {
419    return Create(Xor, LHS, RHS, Ctx);
420  }
421
422  /// @}
423  /// @name Accessors
424  /// @{
425
426  /// getOpcode - Get the kind of this binary expression.
427  Opcode getOpcode() const { return Op; }
428
429  /// getLHS - Get the left-hand side expression of the binary operator.
430  const MCExpr *getLHS() const { return LHS; }
431
432  /// getRHS - Get the right-hand side expression of the binary operator.
433  const MCExpr *getRHS() const { return RHS; }
434
435  /// @}
436
437  static bool classof(const MCExpr *E) {
438    return E->getKind() == MCExpr::Binary;
439  }
440  static bool classof(const MCBinaryExpr *) { return true; }
441};
442
443/// MCTargetExpr - This is an extension point for target-specific MCExpr
444/// subclasses to implement.
445///
446/// NOTE: All subclasses are required to have trivial destructors because
447/// MCExprs are bump pointer allocated and not destructed.
448class MCTargetExpr : public MCExpr {
449  virtual void Anchor();
450protected:
451  MCTargetExpr() : MCExpr(Target) {}
452  virtual ~MCTargetExpr() {}
453public:
454
455  virtual void PrintImpl(raw_ostream &OS) const = 0;
456  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
457                                         const MCAsmLayout *Layout) const = 0;
458  virtual void AddValueSymbols(MCAssembler *) const = 0;
459  virtual const MCSection *FindAssociatedSection() const = 0;
460
461  static bool classof(const MCExpr *E) {
462    return E->getKind() == MCExpr::Target;
463  }
464  static bool classof(const MCTargetExpr *) { return true; }
465};
466
467} // end namespace llvm
468
469#endif
470