MCExpr.h revision 92cfa61c50d01307d658753f8d47f4e8555a6fa9 
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_HA,             // symbol@ha
176    VK_PPC_TOCBASE,        // symbol@tocbase
177    VK_PPC_TOC,            // symbol@toc
178    VK_PPC_TOC_LO,         // symbol@toc@l
179    VK_PPC_TOC_HA,         // symbol@toc@ha
180    VK_PPC_TPREL_LO,       // symbol@tprel@l
181    VK_PPC_TPREL_HA,       // symbol@tprel@ha
182    VK_PPC_DTPREL_LO,      // symbol@dtprel@l
183    VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
184    VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
185    VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
186    VK_PPC_TLS,            // symbol@tls
187    VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
188    VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
189    VK_PPC_TLSGD,          // symbol@tlsgd
190    VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
191    VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
192    VK_PPC_TLSLD,          // symbol@tlsld
193
194    VK_Mips_GPREL,
195    VK_Mips_GOT_CALL,
196    VK_Mips_GOT16,
197    VK_Mips_GOT,
198    VK_Mips_ABS_HI,
199    VK_Mips_ABS_LO,
200    VK_Mips_TLSGD,
201    VK_Mips_TLSLDM,
202    VK_Mips_DTPREL_HI,
203    VK_Mips_DTPREL_LO,
204    VK_Mips_GOTTPREL,
205    VK_Mips_TPREL_HI,
206    VK_Mips_TPREL_LO,
207    VK_Mips_GPOFF_HI,
208    VK_Mips_GPOFF_LO,
209    VK_Mips_GOT_DISP,
210    VK_Mips_GOT_PAGE,
211    VK_Mips_GOT_OFST,
212    VK_Mips_HIGHER,
213    VK_Mips_HIGHEST,
214    VK_Mips_GOT_HI16,
215    VK_Mips_GOT_LO16,
216    VK_Mips_CALL_HI16,
217    VK_Mips_CALL_LO16,
218
219    VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
220  };
221
222private:
223  /// The symbol being referenced.
224  const MCSymbol *Symbol;
225
226  /// The symbol reference modifier.
227  const VariantKind Kind;
228
229  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
230    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
231    assert(Symbol);
232  }
233
234public:
235  /// @name Construction
236  /// @{
237
238  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
239    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
240  }
241
242  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
243                                       MCContext &Ctx);
244  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
245                                       MCContext &Ctx);
246
247  /// @}
248  /// @name Accessors
249  /// @{
250
251  const MCSymbol &getSymbol() const { return *Symbol; }
252
253  VariantKind getKind() const { return Kind; }
254
255  /// @}
256  /// @name Static Utility Functions
257  /// @{
258
259  static StringRef getVariantKindName(VariantKind Kind);
260
261  static VariantKind getVariantKindForName(StringRef Name);
262
263  /// @}
264
265  static bool classof(const MCExpr *E) {
266    return E->getKind() == MCExpr::SymbolRef;
267  }
268};
269
270/// MCUnaryExpr - Unary assembler expressions.
271class MCUnaryExpr : public MCExpr {
272public:
273  enum Opcode {
274    LNot,  ///< Logical negation.
275    Minus, ///< Unary minus.
276    Not,   ///< Bitwise negation.
277    Plus   ///< Unary plus.
278  };
279
280private:
281  Opcode Op;
282  const MCExpr *Expr;
283
284  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
285    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
286
287public:
288  /// @name Construction
289  /// @{
290
291  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
292                                   MCContext &Ctx);
293  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
294    return Create(LNot, Expr, Ctx);
295  }
296  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
297    return Create(Minus, Expr, Ctx);
298  }
299  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
300    return Create(Not, Expr, Ctx);
301  }
302  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
303    return Create(Plus, Expr, Ctx);
304  }
305
306  /// @}
307  /// @name Accessors
308  /// @{
309
310  /// getOpcode - Get the kind of this unary expression.
311  Opcode getOpcode() const { return Op; }
312
313  /// getSubExpr - Get the child of this unary expression.
314  const MCExpr *getSubExpr() const { return Expr; }
315
316  /// @}
317
318  static bool classof(const MCExpr *E) {
319    return E->getKind() == MCExpr::Unary;
320  }
321};
322
323/// MCBinaryExpr - Binary assembler expressions.
324class MCBinaryExpr : public MCExpr {
325public:
326  enum Opcode {
327    Add,  ///< Addition.
328    And,  ///< Bitwise and.
329    Div,  ///< Signed division.
330    EQ,   ///< Equality comparison.
331    GT,   ///< Signed greater than comparison (result is either 0 or some
332          ///< target-specific non-zero value)
333    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
334          ///< some target-specific non-zero value).
335    LAnd, ///< Logical and.
336    LOr,  ///< Logical or.
337    LT,   ///< Signed less than comparison (result is either 0 or
338          ///< some target-specific non-zero value).
339    LTE,  ///< Signed less than or equal comparison (result is either 0 or
340          ///< some target-specific non-zero value).
341    Mod,  ///< Signed remainder.
342    Mul,  ///< Multiplication.
343    NE,   ///< Inequality comparison.
344    Or,   ///< Bitwise or.
345    Shl,  ///< Shift left.
346    Shr,  ///< Shift right (arithmetic or logical, depending on target)
347    Sub,  ///< Subtraction.
348    Xor   ///< Bitwise exclusive or.
349  };
350
351private:
352  Opcode Op;
353  const MCExpr *LHS, *RHS;
354
355  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
356    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
357
358public:
359  /// @name Construction
360  /// @{
361
362  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
363                                    const MCExpr *RHS, MCContext &Ctx);
364  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
365                                       MCContext &Ctx) {
366    return Create(Add, LHS, RHS, Ctx);
367  }
368  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
369                                       MCContext &Ctx) {
370    return Create(And, LHS, RHS, Ctx);
371  }
372  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
373                                       MCContext &Ctx) {
374    return Create(Div, LHS, RHS, Ctx);
375  }
376  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
377                                      MCContext &Ctx) {
378    return Create(EQ, LHS, RHS, Ctx);
379  }
380  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
381                                      MCContext &Ctx) {
382    return Create(GT, LHS, RHS, Ctx);
383  }
384  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
385                                       MCContext &Ctx) {
386    return Create(GTE, LHS, RHS, Ctx);
387  }
388  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
389                                        MCContext &Ctx) {
390    return Create(LAnd, LHS, RHS, Ctx);
391  }
392  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
393                                       MCContext &Ctx) {
394    return Create(LOr, LHS, RHS, Ctx);
395  }
396  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
397                                      MCContext &Ctx) {
398    return Create(LT, LHS, RHS, Ctx);
399  }
400  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
401                                       MCContext &Ctx) {
402    return Create(LTE, LHS, RHS, Ctx);
403  }
404  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
405                                       MCContext &Ctx) {
406    return Create(Mod, LHS, RHS, Ctx);
407  }
408  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
409                                       MCContext &Ctx) {
410    return Create(Mul, LHS, RHS, Ctx);
411  }
412  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
413                                      MCContext &Ctx) {
414    return Create(NE, LHS, RHS, Ctx);
415  }
416  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
417                                      MCContext &Ctx) {
418    return Create(Or, LHS, RHS, Ctx);
419  }
420  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
421                                       MCContext &Ctx) {
422    return Create(Shl, LHS, RHS, Ctx);
423  }
424  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
425                                       MCContext &Ctx) {
426    return Create(Shr, LHS, RHS, Ctx);
427  }
428  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
429                                       MCContext &Ctx) {
430    return Create(Sub, LHS, RHS, Ctx);
431  }
432  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
433                                       MCContext &Ctx) {
434    return Create(Xor, LHS, RHS, Ctx);
435  }
436
437  /// @}
438  /// @name Accessors
439  /// @{
440
441  /// getOpcode - Get the kind of this binary expression.
442  Opcode getOpcode() const { return Op; }
443
444  /// getLHS - Get the left-hand side expression of the binary operator.
445  const MCExpr *getLHS() const { return LHS; }
446
447  /// getRHS - Get the right-hand side expression of the binary operator.
448  const MCExpr *getRHS() const { return RHS; }
449
450  /// @}
451
452  static bool classof(const MCExpr *E) {
453    return E->getKind() == MCExpr::Binary;
454  }
455};
456
457/// MCTargetExpr - This is an extension point for target-specific MCExpr
458/// subclasses to implement.
459///
460/// NOTE: All subclasses are required to have trivial destructors because
461/// MCExprs are bump pointer allocated and not destructed.
462class MCTargetExpr : public MCExpr {
463  virtual void anchor();
464protected:
465  MCTargetExpr() : MCExpr(Target) {}
466  virtual ~MCTargetExpr() {}
467public:
468
469  virtual void PrintImpl(raw_ostream &OS) const = 0;
470  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
471                                         const MCAsmLayout *Layout) const = 0;
472  virtual void AddValueSymbols(MCAssembler *) const = 0;
473  virtual const MCSection *FindAssociatedSection() const = 0;
474
475  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
476
477  static bool classof(const MCExpr *E) {
478    return E->getKind() == MCExpr::Target;
479  }
480};
481
482} // end namespace llvm
483
484#endif
485