MCExpr.h revision 263508 
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_NONE,
164    VK_ARM_PLT,   // ARM-style PLT references. i.e., (PLT) instead of @PLT
165    VK_ARM_TLSGD, //   ditto for TLSGD, GOT, GOTOFF, TPOFF and GOTTPOFF
166    VK_ARM_GOT,
167    VK_ARM_GOTOFF,
168    VK_ARM_TPOFF,
169    VK_ARM_GOTTPOFF,
170    VK_ARM_TARGET1,
171    VK_ARM_TARGET2,
172    VK_ARM_PREL31,
173
174    VK_PPC_LO,             // symbol@l
175    VK_PPC_HI,             // symbol@h
176    VK_PPC_HA,             // symbol@ha
177    VK_PPC_HIGHER,         // symbol@higher
178    VK_PPC_HIGHERA,        // symbol@highera
179    VK_PPC_HIGHEST,        // symbol@highest
180    VK_PPC_HIGHESTA,       // symbol@highesta
181    VK_PPC_GOT_LO,         // symbol@got@l
182    VK_PPC_GOT_HI,         // symbol@got@h
183    VK_PPC_GOT_HA,         // symbol@got@ha
184    VK_PPC_TOCBASE,        // symbol@tocbase
185    VK_PPC_TOC,            // symbol@toc
186    VK_PPC_TOC_LO,         // symbol@toc@l
187    VK_PPC_TOC_HI,         // symbol@toc@h
188    VK_PPC_TOC_HA,         // symbol@toc@ha
189    VK_PPC_DTPMOD,         // symbol@dtpmod
190    VK_PPC_TPREL,          // symbol@tprel
191    VK_PPC_TPREL_LO,       // symbol@tprel@l
192    VK_PPC_TPREL_HI,       // symbol@tprel@h
193    VK_PPC_TPREL_HA,       // symbol@tprel@ha
194    VK_PPC_TPREL_HIGHER,   // symbol@tprel@higher
195    VK_PPC_TPREL_HIGHERA,  // symbol@tprel@highera
196    VK_PPC_TPREL_HIGHEST,  // symbol@tprel@highest
197    VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
198    VK_PPC_DTPREL,         // symbol@dtprel
199    VK_PPC_DTPREL_LO,      // symbol@dtprel@l
200    VK_PPC_DTPREL_HI,      // symbol@dtprel@h
201    VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
202    VK_PPC_DTPREL_HIGHER,  // symbol@dtprel@higher
203    VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
204    VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
205    VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
206    VK_PPC_GOT_TPREL,      // symbol@got@tprel
207    VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
208    VK_PPC_GOT_TPREL_HI,   // symbol@got@tprel@h
209    VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
210    VK_PPC_GOT_DTPREL,     // symbol@got@dtprel
211    VK_PPC_GOT_DTPREL_LO,  // symbol@got@dtprel@l
212    VK_PPC_GOT_DTPREL_HI,  // symbol@got@dtprel@h
213    VK_PPC_GOT_DTPREL_HA,  // symbol@got@dtprel@ha
214    VK_PPC_TLS,            // symbol@tls
215    VK_PPC_GOT_TLSGD,      // symbol@got@tlsgd
216    VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
217    VK_PPC_GOT_TLSGD_HI,   // symbol@got@tlsgd@h
218    VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
219    VK_PPC_TLSGD,          // symbol@tlsgd
220    VK_PPC_GOT_TLSLD,      // symbol@got@tlsld
221    VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
222    VK_PPC_GOT_TLSLD_HI,   // symbol@got@tlsld@h
223    VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
224    VK_PPC_TLSLD,          // symbol@tlsld
225
226    VK_Mips_GPREL,
227    VK_Mips_GOT_CALL,
228    VK_Mips_GOT16,
229    VK_Mips_GOT,
230    VK_Mips_ABS_HI,
231    VK_Mips_ABS_LO,
232    VK_Mips_TLSGD,
233    VK_Mips_TLSLDM,
234    VK_Mips_DTPREL_HI,
235    VK_Mips_DTPREL_LO,
236    VK_Mips_GOTTPREL,
237    VK_Mips_TPREL_HI,
238    VK_Mips_TPREL_LO,
239    VK_Mips_GPOFF_HI,
240    VK_Mips_GPOFF_LO,
241    VK_Mips_GOT_DISP,
242    VK_Mips_GOT_PAGE,
243    VK_Mips_GOT_OFST,
244    VK_Mips_HIGHER,
245    VK_Mips_HIGHEST,
246    VK_Mips_GOT_HI16,
247    VK_Mips_GOT_LO16,
248    VK_Mips_CALL_HI16,
249    VK_Mips_CALL_LO16,
250
251    VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
252  };
253
254private:
255  /// The symbol being referenced.
256  const MCSymbol *Symbol;
257
258  /// The symbol reference modifier.
259  const VariantKind Kind;
260
261  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
262    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
263    assert(Symbol);
264  }
265
266public:
267  /// @name Construction
268  /// @{
269
270  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
271    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
272  }
273
274  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
275                                       MCContext &Ctx);
276  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
277                                       MCContext &Ctx);
278
279  /// @}
280  /// @name Accessors
281  /// @{
282
283  const MCSymbol &getSymbol() const { return *Symbol; }
284
285  VariantKind getKind() const { return Kind; }
286
287  /// @}
288  /// @name Static Utility Functions
289  /// @{
290
291  static StringRef getVariantKindName(VariantKind Kind);
292
293  static VariantKind getVariantKindForName(StringRef Name);
294
295  /// @}
296
297  static bool classof(const MCExpr *E) {
298    return E->getKind() == MCExpr::SymbolRef;
299  }
300};
301
302/// MCUnaryExpr - Unary assembler expressions.
303class MCUnaryExpr : public MCExpr {
304public:
305  enum Opcode {
306    LNot,  ///< Logical negation.
307    Minus, ///< Unary minus.
308    Not,   ///< Bitwise negation.
309    Plus   ///< Unary plus.
310  };
311
312private:
313  Opcode Op;
314  const MCExpr *Expr;
315
316  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
317    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
318
319public:
320  /// @name Construction
321  /// @{
322
323  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
324                                   MCContext &Ctx);
325  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
326    return Create(LNot, Expr, Ctx);
327  }
328  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
329    return Create(Minus, Expr, Ctx);
330  }
331  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
332    return Create(Not, Expr, Ctx);
333  }
334  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
335    return Create(Plus, Expr, Ctx);
336  }
337
338  /// @}
339  /// @name Accessors
340  /// @{
341
342  /// getOpcode - Get the kind of this unary expression.
343  Opcode getOpcode() const { return Op; }
344
345  /// getSubExpr - Get the child of this unary expression.
346  const MCExpr *getSubExpr() const { return Expr; }
347
348  /// @}
349
350  static bool classof(const MCExpr *E) {
351    return E->getKind() == MCExpr::Unary;
352  }
353};
354
355/// MCBinaryExpr - Binary assembler expressions.
356class MCBinaryExpr : public MCExpr {
357public:
358  enum Opcode {
359    Add,  ///< Addition.
360    And,  ///< Bitwise and.
361    Div,  ///< Signed division.
362    EQ,   ///< Equality comparison.
363    GT,   ///< Signed greater than comparison (result is either 0 or some
364          ///< target-specific non-zero value)
365    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
366          ///< some target-specific non-zero value).
367    LAnd, ///< Logical and.
368    LOr,  ///< Logical or.
369    LT,   ///< Signed less than comparison (result is either 0 or
370          ///< some target-specific non-zero value).
371    LTE,  ///< Signed less than or equal comparison (result is either 0 or
372          ///< some target-specific non-zero value).
373    Mod,  ///< Signed remainder.
374    Mul,  ///< Multiplication.
375    NE,   ///< Inequality comparison.
376    Or,   ///< Bitwise or.
377    Shl,  ///< Shift left.
378    Shr,  ///< Shift right (arithmetic or logical, depending on target)
379    Sub,  ///< Subtraction.
380    Xor   ///< Bitwise exclusive or.
381  };
382
383private:
384  Opcode Op;
385  const MCExpr *LHS, *RHS;
386
387  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
388    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
389
390public:
391  /// @name Construction
392  /// @{
393
394  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
395                                    const MCExpr *RHS, MCContext &Ctx);
396  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
397                                       MCContext &Ctx) {
398    return Create(Add, LHS, RHS, Ctx);
399  }
400  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
401                                       MCContext &Ctx) {
402    return Create(And, LHS, RHS, Ctx);
403  }
404  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
405                                       MCContext &Ctx) {
406    return Create(Div, LHS, RHS, Ctx);
407  }
408  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
409                                      MCContext &Ctx) {
410    return Create(EQ, LHS, RHS, Ctx);
411  }
412  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
413                                      MCContext &Ctx) {
414    return Create(GT, LHS, RHS, Ctx);
415  }
416  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
417                                       MCContext &Ctx) {
418    return Create(GTE, LHS, RHS, Ctx);
419  }
420  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
421                                        MCContext &Ctx) {
422    return Create(LAnd, LHS, RHS, Ctx);
423  }
424  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
425                                       MCContext &Ctx) {
426    return Create(LOr, LHS, RHS, Ctx);
427  }
428  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
429                                      MCContext &Ctx) {
430    return Create(LT, LHS, RHS, Ctx);
431  }
432  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
433                                       MCContext &Ctx) {
434    return Create(LTE, LHS, RHS, Ctx);
435  }
436  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
437                                       MCContext &Ctx) {
438    return Create(Mod, LHS, RHS, Ctx);
439  }
440  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
441                                       MCContext &Ctx) {
442    return Create(Mul, LHS, RHS, Ctx);
443  }
444  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
445                                      MCContext &Ctx) {
446    return Create(NE, LHS, RHS, Ctx);
447  }
448  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
449                                      MCContext &Ctx) {
450    return Create(Or, LHS, RHS, Ctx);
451  }
452  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
453                                       MCContext &Ctx) {
454    return Create(Shl, LHS, RHS, Ctx);
455  }
456  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
457                                       MCContext &Ctx) {
458    return Create(Shr, LHS, RHS, Ctx);
459  }
460  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
461                                       MCContext &Ctx) {
462    return Create(Sub, LHS, RHS, Ctx);
463  }
464  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
465                                       MCContext &Ctx) {
466    return Create(Xor, LHS, RHS, Ctx);
467  }
468
469  /// @}
470  /// @name Accessors
471  /// @{
472
473  /// getOpcode - Get the kind of this binary expression.
474  Opcode getOpcode() const { return Op; }
475
476  /// getLHS - Get the left-hand side expression of the binary operator.
477  const MCExpr *getLHS() const { return LHS; }
478
479  /// getRHS - Get the right-hand side expression of the binary operator.
480  const MCExpr *getRHS() const { return RHS; }
481
482  /// @}
483
484  static bool classof(const MCExpr *E) {
485    return E->getKind() == MCExpr::Binary;
486  }
487};
488
489/// MCTargetExpr - This is an extension point for target-specific MCExpr
490/// subclasses to implement.
491///
492/// NOTE: All subclasses are required to have trivial destructors because
493/// MCExprs are bump pointer allocated and not destructed.
494class MCTargetExpr : public MCExpr {
495  virtual void anchor();
496protected:
497  MCTargetExpr() : MCExpr(Target) {}
498  virtual ~MCTargetExpr() {}
499public:
500
501  virtual void PrintImpl(raw_ostream &OS) const = 0;
502  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
503                                         const MCAsmLayout *Layout) const = 0;
504  virtual void AddValueSymbols(MCAssembler *) const = 0;
505  virtual const MCSection *FindAssociatedSection() const = 0;
506
507  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
508
509  static bool classof(const MCExpr *E) {
510    return E->getKind() == MCExpr::Target;
511  }
512};
513
514} // end namespace llvm
515
516#endif
517