MCExpr.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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 MCAsmInfo;
19class MCAsmLayout;
20class MCAssembler;
21class MCContext;
22class MCSection;
23class MCSectionData;
24class MCSymbol;
25class MCValue;
26class raw_ostream;
27class StringRef;
28typedef DenseMap<const MCSectionData*, uint64_t> SectionAddrMap;
29
30/// MCExpr - Base class for the full range of assembler expressions which are
31/// needed for parsing.
32class MCExpr {
33public:
34  enum ExprKind {
35    Binary,    ///< Binary expressions.
36    Constant,  ///< Constant expressions.
37    SymbolRef, ///< References to labels and assigned expressions.
38    Unary,     ///< Unary expressions.
39    Target     ///< Target specific expression.
40  };
41
42private:
43  ExprKind Kind;
44
45  MCExpr(const MCExpr&) LLVM_DELETED_FUNCTION;
46  void operator=(const MCExpr&) LLVM_DELETED_FUNCTION;
47
48  bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
49                          const MCAsmLayout *Layout,
50                          const SectionAddrMap *Addrs) const;
51protected:
52  explicit MCExpr(ExprKind _Kind) : Kind(_Kind) {}
53
54  bool EvaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
55                                 const MCAsmLayout *Layout,
56                                 const SectionAddrMap *Addrs, bool InSet,
57                                 bool ForceVarExpansion) const;
58
59public:
60  /// @name Accessors
61  /// @{
62
63  ExprKind getKind() const { return Kind; }
64
65  /// @}
66  /// @name Utility Methods
67  /// @{
68
69  void print(raw_ostream &OS) const;
70  void dump() const;
71
72  /// @}
73  /// @name Expression Evaluation
74  /// @{
75
76  /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
77  ///
78  /// @param Res - The absolute value, if evaluation succeeds.
79  /// @param Layout - The assembler layout object to use for evaluating symbol
80  /// values. If not given, then only non-symbolic expressions will be
81  /// evaluated.
82  /// @result - True on success.
83  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
84                          const SectionAddrMap &Addrs) const;
85  bool EvaluateAsAbsolute(int64_t &Res) const;
86  bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
87  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
88
89  /// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
90  /// value, i.e. an expression of the fixed form (a - b + constant).
91  ///
92  /// @param Res - The relocatable value, if evaluation succeeds.
93  /// @param Layout - The assembler layout object to use for evaluating values.
94  /// @result - True on success.
95  bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout) const;
96
97  /// \brief Try to evaluate the expression to the form (a - b + constant) where
98  /// neither a nor b are variables.
99  ///
100  /// This is a more aggressive variant of EvaluateAsRelocatable. The intended
101  /// use is for when relocations are not available, like the symbol value in
102  /// the symbol table.
103  bool EvaluateAsValue(MCValue &Res, const MCAsmLayout *Layout) const;
104
105  /// FindAssociatedSection - Find the "associated section" for this expression,
106  /// which is currently defined as the absolute section for constants, or
107  /// otherwise the section associated with the first defined symbol in the
108  /// expression.
109  const MCSection *FindAssociatedSection() const;
110
111  /// @}
112};
113
114inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
115  E.print(OS);
116  return OS;
117}
118
119//// MCConstantExpr - Represent a constant integer expression.
120class MCConstantExpr : public MCExpr {
121  int64_t Value;
122
123  explicit MCConstantExpr(int64_t _Value)
124    : MCExpr(MCExpr::Constant), Value(_Value) {}
125
126public:
127  /// @name Construction
128  /// @{
129
130  static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
131
132  /// @}
133  /// @name Accessors
134  /// @{
135
136  int64_t getValue() const { return Value; }
137
138  /// @}
139
140  static bool classof(const MCExpr *E) {
141    return E->getKind() == MCExpr::Constant;
142  }
143};
144
145/// MCSymbolRefExpr - Represent a reference to a symbol from inside an
146/// expression.
147///
148/// A symbol reference in an expression may be a use of a label, a use of an
149/// assembler variable (defined constant), or constitute an implicit definition
150/// of the symbol as external.
151class MCSymbolRefExpr : public MCExpr {
152public:
153  enum VariantKind {
154    VK_None,
155    VK_Invalid,
156
157    VK_GOT,
158    VK_GOTOFF,
159    VK_GOTPCREL,
160    VK_GOTTPOFF,
161    VK_INDNTPOFF,
162    VK_NTPOFF,
163    VK_GOTNTPOFF,
164    VK_PLT,
165    VK_TLSGD,
166    VK_TLSLD,
167    VK_TLSLDM,
168    VK_TPOFF,
169    VK_DTPOFF,
170    VK_TLVP,      // Mach-O thread local variable relocations
171    VK_TLVPPAGE,
172    VK_TLVPPAGEOFF,
173    VK_PAGE,
174    VK_PAGEOFF,
175    VK_GOTPAGE,
176    VK_GOTPAGEOFF,
177    VK_SECREL,
178    VK_WEAKREF,   // The link between the symbols in .weakref foo, bar
179
180    VK_ARM_NONE,
181    VK_ARM_TARGET1,
182    VK_ARM_TARGET2,
183    VK_ARM_PREL31,
184    VK_ARM_TLSLDO,         // symbol(tlsldo)
185    VK_ARM_TLSCALL,        // symbol(tlscall)
186    VK_ARM_TLSDESC,        // symbol(tlsdesc)
187    VK_ARM_TLSDESCSEQ,
188
189    VK_PPC_LO,             // symbol@l
190    VK_PPC_HI,             // symbol@h
191    VK_PPC_HA,             // symbol@ha
192    VK_PPC_HIGHER,         // symbol@higher
193    VK_PPC_HIGHERA,        // symbol@highera
194    VK_PPC_HIGHEST,        // symbol@highest
195    VK_PPC_HIGHESTA,       // symbol@highesta
196    VK_PPC_GOT_LO,         // symbol@got@l
197    VK_PPC_GOT_HI,         // symbol@got@h
198    VK_PPC_GOT_HA,         // symbol@got@ha
199    VK_PPC_TOCBASE,        // symbol@tocbase
200    VK_PPC_TOC,            // symbol@toc
201    VK_PPC_TOC_LO,         // symbol@toc@l
202    VK_PPC_TOC_HI,         // symbol@toc@h
203    VK_PPC_TOC_HA,         // symbol@toc@ha
204    VK_PPC_DTPMOD,         // symbol@dtpmod
205    VK_PPC_TPREL,          // symbol@tprel
206    VK_PPC_TPREL_LO,       // symbol@tprel@l
207    VK_PPC_TPREL_HI,       // symbol@tprel@h
208    VK_PPC_TPREL_HA,       // symbol@tprel@ha
209    VK_PPC_TPREL_HIGHER,   // symbol@tprel@higher
210    VK_PPC_TPREL_HIGHERA,  // symbol@tprel@highera
211    VK_PPC_TPREL_HIGHEST,  // symbol@tprel@highest
212    VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
213    VK_PPC_DTPREL,         // symbol@dtprel
214    VK_PPC_DTPREL_LO,      // symbol@dtprel@l
215    VK_PPC_DTPREL_HI,      // symbol@dtprel@h
216    VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
217    VK_PPC_DTPREL_HIGHER,  // symbol@dtprel@higher
218    VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
219    VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
220    VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
221    VK_PPC_GOT_TPREL,      // symbol@got@tprel
222    VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
223    VK_PPC_GOT_TPREL_HI,   // symbol@got@tprel@h
224    VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
225    VK_PPC_GOT_DTPREL,     // symbol@got@dtprel
226    VK_PPC_GOT_DTPREL_LO,  // symbol@got@dtprel@l
227    VK_PPC_GOT_DTPREL_HI,  // symbol@got@dtprel@h
228    VK_PPC_GOT_DTPREL_HA,  // symbol@got@dtprel@ha
229    VK_PPC_TLS,            // symbol@tls
230    VK_PPC_GOT_TLSGD,      // symbol@got@tlsgd
231    VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
232    VK_PPC_GOT_TLSGD_HI,   // symbol@got@tlsgd@h
233    VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
234    VK_PPC_TLSGD,          // symbol@tlsgd
235    VK_PPC_GOT_TLSLD,      // symbol@got@tlsld
236    VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
237    VK_PPC_GOT_TLSLD_HI,   // symbol@got@tlsld@h
238    VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
239    VK_PPC_TLSLD,          // symbol@tlsld
240
241    VK_Mips_GPREL,
242    VK_Mips_GOT_CALL,
243    VK_Mips_GOT16,
244    VK_Mips_GOT,
245    VK_Mips_ABS_HI,
246    VK_Mips_ABS_LO,
247    VK_Mips_TLSGD,
248    VK_Mips_TLSLDM,
249    VK_Mips_DTPREL_HI,
250    VK_Mips_DTPREL_LO,
251    VK_Mips_GOTTPREL,
252    VK_Mips_TPREL_HI,
253    VK_Mips_TPREL_LO,
254    VK_Mips_GPOFF_HI,
255    VK_Mips_GPOFF_LO,
256    VK_Mips_GOT_DISP,
257    VK_Mips_GOT_PAGE,
258    VK_Mips_GOT_OFST,
259    VK_Mips_HIGHER,
260    VK_Mips_HIGHEST,
261    VK_Mips_GOT_HI16,
262    VK_Mips_GOT_LO16,
263    VK_Mips_CALL_HI16,
264    VK_Mips_CALL_LO16,
265    VK_Mips_PCREL_HI16,
266    VK_Mips_PCREL_LO16,
267
268    VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
269  };
270
271private:
272  /// The symbol being referenced.
273  const MCSymbol *Symbol;
274
275  /// The symbol reference modifier.
276  const VariantKind Kind;
277
278  /// MCAsmInfo that is used to print symbol variants correctly.
279  const MCAsmInfo *MAI;
280
281  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind,
282                           const MCAsmInfo *_MAI)
283    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind), MAI(_MAI) {
284    assert(Symbol);
285    assert(MAI);
286  }
287
288public:
289  /// @name Construction
290  /// @{
291
292  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
293    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
294  }
295
296  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
297                                       MCContext &Ctx);
298  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
299                                       MCContext &Ctx);
300
301  /// @}
302  /// @name Accessors
303  /// @{
304
305  const MCSymbol &getSymbol() const { return *Symbol; }
306  const MCAsmInfo &getMCAsmInfo() const { return *MAI; }
307
308  VariantKind getKind() const { return Kind; }
309
310  /// @}
311  /// @name Static Utility Functions
312  /// @{
313
314  static StringRef getVariantKindName(VariantKind Kind);
315
316  static VariantKind getVariantKindForName(StringRef Name);
317
318  /// @}
319
320  static bool classof(const MCExpr *E) {
321    return E->getKind() == MCExpr::SymbolRef;
322  }
323};
324
325/// MCUnaryExpr - Unary assembler expressions.
326class MCUnaryExpr : public MCExpr {
327public:
328  enum Opcode {
329    LNot,  ///< Logical negation.
330    Minus, ///< Unary minus.
331    Not,   ///< Bitwise negation.
332    Plus   ///< Unary plus.
333  };
334
335private:
336  Opcode Op;
337  const MCExpr *Expr;
338
339  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
340    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
341
342public:
343  /// @name Construction
344  /// @{
345
346  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
347                                   MCContext &Ctx);
348  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
349    return Create(LNot, Expr, Ctx);
350  }
351  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
352    return Create(Minus, Expr, Ctx);
353  }
354  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
355    return Create(Not, Expr, Ctx);
356  }
357  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
358    return Create(Plus, Expr, Ctx);
359  }
360
361  /// @}
362  /// @name Accessors
363  /// @{
364
365  /// getOpcode - Get the kind of this unary expression.
366  Opcode getOpcode() const { return Op; }
367
368  /// getSubExpr - Get the child of this unary expression.
369  const MCExpr *getSubExpr() const { return Expr; }
370
371  /// @}
372
373  static bool classof(const MCExpr *E) {
374    return E->getKind() == MCExpr::Unary;
375  }
376};
377
378/// MCBinaryExpr - Binary assembler expressions.
379class MCBinaryExpr : public MCExpr {
380public:
381  enum Opcode {
382    Add,  ///< Addition.
383    And,  ///< Bitwise and.
384    Div,  ///< Signed division.
385    EQ,   ///< Equality comparison.
386    GT,   ///< Signed greater than comparison (result is either 0 or some
387          ///< target-specific non-zero value)
388    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
389          ///< some target-specific non-zero value).
390    LAnd, ///< Logical and.
391    LOr,  ///< Logical or.
392    LT,   ///< Signed less than comparison (result is either 0 or
393          ///< some target-specific non-zero value).
394    LTE,  ///< Signed less than or equal comparison (result is either 0 or
395          ///< some target-specific non-zero value).
396    Mod,  ///< Signed remainder.
397    Mul,  ///< Multiplication.
398    NE,   ///< Inequality comparison.
399    Or,   ///< Bitwise or.
400    Shl,  ///< Shift left.
401    Shr,  ///< Shift right (arithmetic or logical, depending on target)
402    Sub,  ///< Subtraction.
403    Xor   ///< Bitwise exclusive or.
404  };
405
406private:
407  Opcode Op;
408  const MCExpr *LHS, *RHS;
409
410  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
411    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
412
413public:
414  /// @name Construction
415  /// @{
416
417  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
418                                    const MCExpr *RHS, MCContext &Ctx);
419  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
420                                       MCContext &Ctx) {
421    return Create(Add, LHS, RHS, Ctx);
422  }
423  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
424                                       MCContext &Ctx) {
425    return Create(And, LHS, RHS, Ctx);
426  }
427  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
428                                       MCContext &Ctx) {
429    return Create(Div, LHS, RHS, Ctx);
430  }
431  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
432                                      MCContext &Ctx) {
433    return Create(EQ, LHS, RHS, Ctx);
434  }
435  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
436                                      MCContext &Ctx) {
437    return Create(GT, LHS, RHS, Ctx);
438  }
439  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
440                                       MCContext &Ctx) {
441    return Create(GTE, LHS, RHS, Ctx);
442  }
443  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
444                                        MCContext &Ctx) {
445    return Create(LAnd, LHS, RHS, Ctx);
446  }
447  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
448                                       MCContext &Ctx) {
449    return Create(LOr, LHS, RHS, Ctx);
450  }
451  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
452                                      MCContext &Ctx) {
453    return Create(LT, LHS, RHS, Ctx);
454  }
455  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
456                                       MCContext &Ctx) {
457    return Create(LTE, LHS, RHS, Ctx);
458  }
459  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
460                                       MCContext &Ctx) {
461    return Create(Mod, LHS, RHS, Ctx);
462  }
463  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
464                                       MCContext &Ctx) {
465    return Create(Mul, LHS, RHS, Ctx);
466  }
467  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
468                                      MCContext &Ctx) {
469    return Create(NE, LHS, RHS, Ctx);
470  }
471  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
472                                      MCContext &Ctx) {
473    return Create(Or, LHS, RHS, Ctx);
474  }
475  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
476                                       MCContext &Ctx) {
477    return Create(Shl, LHS, RHS, Ctx);
478  }
479  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
480                                       MCContext &Ctx) {
481    return Create(Shr, LHS, RHS, Ctx);
482  }
483  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
484                                       MCContext &Ctx) {
485    return Create(Sub, LHS, RHS, Ctx);
486  }
487  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
488                                       MCContext &Ctx) {
489    return Create(Xor, LHS, RHS, Ctx);
490  }
491
492  /// @}
493  /// @name Accessors
494  /// @{
495
496  /// getOpcode - Get the kind of this binary expression.
497  Opcode getOpcode() const { return Op; }
498
499  /// getLHS - Get the left-hand side expression of the binary operator.
500  const MCExpr *getLHS() const { return LHS; }
501
502  /// getRHS - Get the right-hand side expression of the binary operator.
503  const MCExpr *getRHS() const { return RHS; }
504
505  /// @}
506
507  static bool classof(const MCExpr *E) {
508    return E->getKind() == MCExpr::Binary;
509  }
510};
511
512/// MCTargetExpr - This is an extension point for target-specific MCExpr
513/// subclasses to implement.
514///
515/// NOTE: All subclasses are required to have trivial destructors because
516/// MCExprs are bump pointer allocated and not destructed.
517class MCTargetExpr : public MCExpr {
518  virtual void anchor();
519protected:
520  MCTargetExpr() : MCExpr(Target) {}
521  virtual ~MCTargetExpr() {}
522public:
523
524  virtual void PrintImpl(raw_ostream &OS) const = 0;
525  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
526                                         const MCAsmLayout *Layout) const = 0;
527  virtual void AddValueSymbols(MCAssembler *) const = 0;
528  virtual const MCSection *FindAssociatedSection() const = 0;
529
530  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
531
532  static bool classof(const MCExpr *E) {
533    return E->getKind() == MCExpr::Target;
534  }
535};
536
537} // end namespace llvm
538
539#endif
540