MCExpr.h revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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,
57                                 bool InSet) const;
58public:
59  /// @name Accessors
60  /// @{
61
62  ExprKind getKind() const { return Kind; }
63
64  /// @}
65  /// @name Utility Methods
66  /// @{
67
68  void print(raw_ostream &OS) const;
69  void dump() const;
70
71  /// @}
72  /// @name Expression Evaluation
73  /// @{
74
75  /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
76  ///
77  /// @param Res - The absolute value, if evaluation succeeds.
78  /// @param Layout - The assembler layout object to use for evaluating symbol
79  /// values. If not given, then only non-symbolic expressions will be
80  /// evaluated.
81  /// @result - True on success.
82  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
83                          const SectionAddrMap &Addrs) const;
84  bool EvaluateAsAbsolute(int64_t &Res) const;
85  bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
86  bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
87
88  /// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
89  /// value, i.e. an expression of the fixed form (a - b + constant).
90  ///
91  /// @param Res - The relocatable value, if evaluation succeeds.
92  /// @param Layout - The assembler layout object to use for evaluating values.
93  /// @result - True on success.
94  bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout) const;
95
96  /// FindAssociatedSection - Find the "associated section" for this expression,
97  /// which is currently defined as the absolute section for constants, or
98  /// otherwise the section associated with the first defined symbol in the
99  /// expression.
100  const MCSection *FindAssociatedSection() const;
101
102  /// @}
103};
104
105inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
106  E.print(OS);
107  return OS;
108}
109
110//// MCConstantExpr - Represent a constant integer expression.
111class MCConstantExpr : public MCExpr {
112  int64_t Value;
113
114  explicit MCConstantExpr(int64_t _Value)
115    : MCExpr(MCExpr::Constant), Value(_Value) {}
116
117public:
118  /// @name Construction
119  /// @{
120
121  static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
122
123  /// @}
124  /// @name Accessors
125  /// @{
126
127  int64_t getValue() const { return Value; }
128
129  /// @}
130
131  static bool classof(const MCExpr *E) {
132    return E->getKind() == MCExpr::Constant;
133  }
134};
135
136/// MCSymbolRefExpr - Represent a reference to a symbol from inside an
137/// expression.
138///
139/// A symbol reference in an expression may be a use of a label, a use of an
140/// assembler variable (defined constant), or constitute an implicit definition
141/// of the symbol as external.
142class MCSymbolRefExpr : public MCExpr {
143public:
144  enum VariantKind {
145    VK_None,
146    VK_Invalid,
147
148    VK_GOT,
149    VK_GOTOFF,
150    VK_GOTPCREL,
151    VK_GOTTPOFF,
152    VK_INDNTPOFF,
153    VK_NTPOFF,
154    VK_GOTNTPOFF,
155    VK_PLT,
156    VK_TLSGD,
157    VK_TLSLD,
158    VK_TLSLDM,
159    VK_TPOFF,
160    VK_DTPOFF,
161    VK_TLVP,      // Mach-O thread local variable relocations
162    VK_TLVPPAGE,
163    VK_TLVPPAGEOFF,
164    VK_PAGE,
165    VK_PAGEOFF,
166    VK_GOTPAGE,
167    VK_GOTPAGEOFF,
168    VK_SECREL,
169    VK_WEAKREF,   // The link between the symbols in .weakref foo, bar
170
171    VK_ARM_NONE,
172    VK_ARM_TARGET1,
173    VK_ARM_TARGET2,
174    VK_ARM_PREL31,
175    VK_ARM_TLSLDO,         // symbol(tlsldo)
176    VK_ARM_TLSCALL,        // symbol(tlscall)
177    VK_ARM_TLSDESC,        // symbol(tlsdesc)
178    VK_ARM_TLSDESCSEQ,
179
180    VK_PPC_LO,             // symbol@l
181    VK_PPC_HI,             // symbol@h
182    VK_PPC_HA,             // symbol@ha
183    VK_PPC_HIGHER,         // symbol@higher
184    VK_PPC_HIGHERA,        // symbol@highera
185    VK_PPC_HIGHEST,        // symbol@highest
186    VK_PPC_HIGHESTA,       // symbol@highesta
187    VK_PPC_GOT_LO,         // symbol@got@l
188    VK_PPC_GOT_HI,         // symbol@got@h
189    VK_PPC_GOT_HA,         // symbol@got@ha
190    VK_PPC_TOCBASE,        // symbol@tocbase
191    VK_PPC_TOC,            // symbol@toc
192    VK_PPC_TOC_LO,         // symbol@toc@l
193    VK_PPC_TOC_HI,         // symbol@toc@h
194    VK_PPC_TOC_HA,         // symbol@toc@ha
195    VK_PPC_DTPMOD,         // symbol@dtpmod
196    VK_PPC_TPREL,          // symbol@tprel
197    VK_PPC_TPREL_LO,       // symbol@tprel@l
198    VK_PPC_TPREL_HI,       // symbol@tprel@h
199    VK_PPC_TPREL_HA,       // symbol@tprel@ha
200    VK_PPC_TPREL_HIGHER,   // symbol@tprel@higher
201    VK_PPC_TPREL_HIGHERA,  // symbol@tprel@highera
202    VK_PPC_TPREL_HIGHEST,  // symbol@tprel@highest
203    VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
204    VK_PPC_DTPREL,         // symbol@dtprel
205    VK_PPC_DTPREL_LO,      // symbol@dtprel@l
206    VK_PPC_DTPREL_HI,      // symbol@dtprel@h
207    VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
208    VK_PPC_DTPREL_HIGHER,  // symbol@dtprel@higher
209    VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
210    VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
211    VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
212    VK_PPC_GOT_TPREL,      // symbol@got@tprel
213    VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
214    VK_PPC_GOT_TPREL_HI,   // symbol@got@tprel@h
215    VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
216    VK_PPC_GOT_DTPREL,     // symbol@got@dtprel
217    VK_PPC_GOT_DTPREL_LO,  // symbol@got@dtprel@l
218    VK_PPC_GOT_DTPREL_HI,  // symbol@got@dtprel@h
219    VK_PPC_GOT_DTPREL_HA,  // symbol@got@dtprel@ha
220    VK_PPC_TLS,            // symbol@tls
221    VK_PPC_GOT_TLSGD,      // symbol@got@tlsgd
222    VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
223    VK_PPC_GOT_TLSGD_HI,   // symbol@got@tlsgd@h
224    VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
225    VK_PPC_TLSGD,          // symbol@tlsgd
226    VK_PPC_GOT_TLSLD,      // symbol@got@tlsld
227    VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
228    VK_PPC_GOT_TLSLD_HI,   // symbol@got@tlsld@h
229    VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
230    VK_PPC_TLSLD,          // symbol@tlsld
231
232    VK_Mips_GPREL,
233    VK_Mips_GOT_CALL,
234    VK_Mips_GOT16,
235    VK_Mips_GOT,
236    VK_Mips_ABS_HI,
237    VK_Mips_ABS_LO,
238    VK_Mips_TLSGD,
239    VK_Mips_TLSLDM,
240    VK_Mips_DTPREL_HI,
241    VK_Mips_DTPREL_LO,
242    VK_Mips_GOTTPREL,
243    VK_Mips_TPREL_HI,
244    VK_Mips_TPREL_LO,
245    VK_Mips_GPOFF_HI,
246    VK_Mips_GPOFF_LO,
247    VK_Mips_GOT_DISP,
248    VK_Mips_GOT_PAGE,
249    VK_Mips_GOT_OFST,
250    VK_Mips_HIGHER,
251    VK_Mips_HIGHEST,
252    VK_Mips_GOT_HI16,
253    VK_Mips_GOT_LO16,
254    VK_Mips_CALL_HI16,
255    VK_Mips_CALL_LO16,
256
257    VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
258  };
259
260private:
261  /// The symbol being referenced.
262  const MCSymbol *Symbol;
263
264  /// The symbol reference modifier.
265  const VariantKind Kind;
266
267  /// MCAsmInfo that is used to print symbol variants correctly.
268  const MCAsmInfo *MAI;
269
270  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind,
271                           const MCAsmInfo *_MAI)
272    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind), MAI(_MAI) {
273    assert(Symbol);
274    assert(MAI);
275  }
276
277public:
278  /// @name Construction
279  /// @{
280
281  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
282    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
283  }
284
285  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
286                                       MCContext &Ctx);
287  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
288                                       MCContext &Ctx);
289
290  /// @}
291  /// @name Accessors
292  /// @{
293
294  const MCSymbol &getSymbol() const { return *Symbol; }
295  const MCAsmInfo &getMCAsmInfo() const { return *MAI; }
296
297  VariantKind getKind() const { return Kind; }
298
299  /// @}
300  /// @name Static Utility Functions
301  /// @{
302
303  static StringRef getVariantKindName(VariantKind Kind);
304
305  static VariantKind getVariantKindForName(StringRef Name);
306
307  /// @}
308
309  static bool classof(const MCExpr *E) {
310    return E->getKind() == MCExpr::SymbolRef;
311  }
312};
313
314/// MCUnaryExpr - Unary assembler expressions.
315class MCUnaryExpr : public MCExpr {
316public:
317  enum Opcode {
318    LNot,  ///< Logical negation.
319    Minus, ///< Unary minus.
320    Not,   ///< Bitwise negation.
321    Plus   ///< Unary plus.
322  };
323
324private:
325  Opcode Op;
326  const MCExpr *Expr;
327
328  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
329    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
330
331public:
332  /// @name Construction
333  /// @{
334
335  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
336                                   MCContext &Ctx);
337  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
338    return Create(LNot, Expr, Ctx);
339  }
340  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
341    return Create(Minus, Expr, Ctx);
342  }
343  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
344    return Create(Not, Expr, Ctx);
345  }
346  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
347    return Create(Plus, Expr, Ctx);
348  }
349
350  /// @}
351  /// @name Accessors
352  /// @{
353
354  /// getOpcode - Get the kind of this unary expression.
355  Opcode getOpcode() const { return Op; }
356
357  /// getSubExpr - Get the child of this unary expression.
358  const MCExpr *getSubExpr() const { return Expr; }
359
360  /// @}
361
362  static bool classof(const MCExpr *E) {
363    return E->getKind() == MCExpr::Unary;
364  }
365};
366
367/// MCBinaryExpr - Binary assembler expressions.
368class MCBinaryExpr : public MCExpr {
369public:
370  enum Opcode {
371    Add,  ///< Addition.
372    And,  ///< Bitwise and.
373    Div,  ///< Signed division.
374    EQ,   ///< Equality comparison.
375    GT,   ///< Signed greater than comparison (result is either 0 or some
376          ///< target-specific non-zero value)
377    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
378          ///< some target-specific non-zero value).
379    LAnd, ///< Logical and.
380    LOr,  ///< Logical or.
381    LT,   ///< Signed less than comparison (result is either 0 or
382          ///< some target-specific non-zero value).
383    LTE,  ///< Signed less than or equal comparison (result is either 0 or
384          ///< some target-specific non-zero value).
385    Mod,  ///< Signed remainder.
386    Mul,  ///< Multiplication.
387    NE,   ///< Inequality comparison.
388    Or,   ///< Bitwise or.
389    Shl,  ///< Shift left.
390    Shr,  ///< Shift right (arithmetic or logical, depending on target)
391    Sub,  ///< Subtraction.
392    Xor   ///< Bitwise exclusive or.
393  };
394
395private:
396  Opcode Op;
397  const MCExpr *LHS, *RHS;
398
399  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
400    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
401
402public:
403  /// @name Construction
404  /// @{
405
406  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
407                                    const MCExpr *RHS, MCContext &Ctx);
408  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
409                                       MCContext &Ctx) {
410    return Create(Add, LHS, RHS, Ctx);
411  }
412  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
413                                       MCContext &Ctx) {
414    return Create(And, LHS, RHS, Ctx);
415  }
416  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
417                                       MCContext &Ctx) {
418    return Create(Div, LHS, RHS, Ctx);
419  }
420  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
421                                      MCContext &Ctx) {
422    return Create(EQ, LHS, RHS, Ctx);
423  }
424  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
425                                      MCContext &Ctx) {
426    return Create(GT, LHS, RHS, Ctx);
427  }
428  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
429                                       MCContext &Ctx) {
430    return Create(GTE, LHS, RHS, Ctx);
431  }
432  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
433                                        MCContext &Ctx) {
434    return Create(LAnd, LHS, RHS, Ctx);
435  }
436  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
437                                       MCContext &Ctx) {
438    return Create(LOr, LHS, RHS, Ctx);
439  }
440  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
441                                      MCContext &Ctx) {
442    return Create(LT, LHS, RHS, Ctx);
443  }
444  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
445                                       MCContext &Ctx) {
446    return Create(LTE, LHS, RHS, Ctx);
447  }
448  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
449                                       MCContext &Ctx) {
450    return Create(Mod, LHS, RHS, Ctx);
451  }
452  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
453                                       MCContext &Ctx) {
454    return Create(Mul, LHS, RHS, Ctx);
455  }
456  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
457                                      MCContext &Ctx) {
458    return Create(NE, LHS, RHS, Ctx);
459  }
460  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
461                                      MCContext &Ctx) {
462    return Create(Or, LHS, RHS, Ctx);
463  }
464  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
465                                       MCContext &Ctx) {
466    return Create(Shl, LHS, RHS, Ctx);
467  }
468  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
469                                       MCContext &Ctx) {
470    return Create(Shr, LHS, RHS, Ctx);
471  }
472  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
473                                       MCContext &Ctx) {
474    return Create(Sub, LHS, RHS, Ctx);
475  }
476  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
477                                       MCContext &Ctx) {
478    return Create(Xor, LHS, RHS, Ctx);
479  }
480
481  /// @}
482  /// @name Accessors
483  /// @{
484
485  /// getOpcode - Get the kind of this binary expression.
486  Opcode getOpcode() const { return Op; }
487
488  /// getLHS - Get the left-hand side expression of the binary operator.
489  const MCExpr *getLHS() const { return LHS; }
490
491  /// getRHS - Get the right-hand side expression of the binary operator.
492  const MCExpr *getRHS() const { return RHS; }
493
494  /// @}
495
496  static bool classof(const MCExpr *E) {
497    return E->getKind() == MCExpr::Binary;
498  }
499};
500
501/// MCTargetExpr - This is an extension point for target-specific MCExpr
502/// subclasses to implement.
503///
504/// NOTE: All subclasses are required to have trivial destructors because
505/// MCExprs are bump pointer allocated and not destructed.
506class MCTargetExpr : public MCExpr {
507  virtual void anchor();
508protected:
509  MCTargetExpr() : MCExpr(Target) {}
510  virtual ~MCTargetExpr() {}
511public:
512
513  virtual void PrintImpl(raw_ostream &OS) const = 0;
514  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
515                                         const MCAsmLayout *Layout) const = 0;
516  virtual void AddValueSymbols(MCAssembler *) const = 0;
517  virtual const MCSection *FindAssociatedSection() const = 0;
518
519  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
520
521  static bool classof(const MCExpr *E) {
522    return E->getKind() == MCExpr::Target;
523  }
524};
525
526} // end namespace llvm
527
528#endif
529