MCExpr.h revision 37c7461fc3f1983a81bfe934855d707fd6572e78 
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_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    VK_PPC_TOC16_HA,     // symbol@toc@ha
183    VK_PPC_TOC16_LO,     // symbol@toc@l
184    VK_PPC_GOT_TPREL16_DS, // symbol@got@tprel
185    VK_PPC_TLS,            // symbol@tls
186    VK_PPC_GOT_TLSGD16_HA, // symbol@got@tlsgd@ha
187    VK_PPC_GOT_TLSGD16_LO, // symbol@got@tlsgd@l
188    VK_PPC_TLSGD,          // symbol@tlsgd
189
190    VK_Mips_GPREL,
191    VK_Mips_GOT_CALL,
192    VK_Mips_GOT16,
193    VK_Mips_GOT,
194    VK_Mips_ABS_HI,
195    VK_Mips_ABS_LO,
196    VK_Mips_TLSGD,
197    VK_Mips_TLSLDM,
198    VK_Mips_DTPREL_HI,
199    VK_Mips_DTPREL_LO,
200    VK_Mips_GOTTPREL,
201    VK_Mips_TPREL_HI,
202    VK_Mips_TPREL_LO,
203    VK_Mips_GPOFF_HI,
204    VK_Mips_GPOFF_LO,
205    VK_Mips_GOT_DISP,
206    VK_Mips_GOT_PAGE,
207    VK_Mips_GOT_OFST,
208    VK_Mips_HIGHER,
209    VK_Mips_HIGHEST,
210    VK_Mips_GOT_HI16,
211    VK_Mips_GOT_LO16,
212    VK_Mips_CALL_HI16,
213    VK_Mips_CALL_LO16
214  };
215
216private:
217  /// The symbol being referenced.
218  const MCSymbol *Symbol;
219
220  /// The symbol reference modifier.
221  const VariantKind Kind;
222
223  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
224    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
225    assert(Symbol);
226  }
227
228public:
229  /// @name Construction
230  /// @{
231
232  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
233    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
234  }
235
236  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
237                                       MCContext &Ctx);
238  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
239                                       MCContext &Ctx);
240
241  /// @}
242  /// @name Accessors
243  /// @{
244
245  const MCSymbol &getSymbol() const { return *Symbol; }
246
247  VariantKind getKind() const { return Kind; }
248
249  /// @}
250  /// @name Static Utility Functions
251  /// @{
252
253  static StringRef getVariantKindName(VariantKind Kind);
254
255  static VariantKind getVariantKindForName(StringRef Name);
256
257  /// @}
258
259  static bool classof(const MCExpr *E) {
260    return E->getKind() == MCExpr::SymbolRef;
261  }
262};
263
264/// MCUnaryExpr - Unary assembler expressions.
265class MCUnaryExpr : public MCExpr {
266public:
267  enum Opcode {
268    LNot,  ///< Logical negation.
269    Minus, ///< Unary minus.
270    Not,   ///< Bitwise negation.
271    Plus   ///< Unary plus.
272  };
273
274private:
275  Opcode Op;
276  const MCExpr *Expr;
277
278  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
279    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
280
281public:
282  /// @name Construction
283  /// @{
284
285  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
286                                   MCContext &Ctx);
287  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
288    return Create(LNot, Expr, Ctx);
289  }
290  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
291    return Create(Minus, Expr, Ctx);
292  }
293  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
294    return Create(Not, Expr, Ctx);
295  }
296  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
297    return Create(Plus, Expr, Ctx);
298  }
299
300  /// @}
301  /// @name Accessors
302  /// @{
303
304  /// getOpcode - Get the kind of this unary expression.
305  Opcode getOpcode() const { return Op; }
306
307  /// getSubExpr - Get the child of this unary expression.
308  const MCExpr *getSubExpr() const { return Expr; }
309
310  /// @}
311
312  static bool classof(const MCExpr *E) {
313    return E->getKind() == MCExpr::Unary;
314  }
315};
316
317/// MCBinaryExpr - Binary assembler expressions.
318class MCBinaryExpr : public MCExpr {
319public:
320  enum Opcode {
321    Add,  ///< Addition.
322    And,  ///< Bitwise and.
323    Div,  ///< Signed division.
324    EQ,   ///< Equality comparison.
325    GT,   ///< Signed greater than comparison (result is either 0 or some
326          ///< target-specific non-zero value)
327    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
328          ///< some target-specific non-zero value).
329    LAnd, ///< Logical and.
330    LOr,  ///< Logical or.
331    LT,   ///< Signed less than comparison (result is either 0 or
332          ///< some target-specific non-zero value).
333    LTE,  ///< Signed less than or equal comparison (result is either 0 or
334          ///< some target-specific non-zero value).
335    Mod,  ///< Signed remainder.
336    Mul,  ///< Multiplication.
337    NE,   ///< Inequality comparison.
338    Or,   ///< Bitwise or.
339    Shl,  ///< Shift left.
340    Shr,  ///< Shift right (arithmetic or logical, depending on target)
341    Sub,  ///< Subtraction.
342    Xor   ///< Bitwise exclusive or.
343  };
344
345private:
346  Opcode Op;
347  const MCExpr *LHS, *RHS;
348
349  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
350    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
351
352public:
353  /// @name Construction
354  /// @{
355
356  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
357                                    const MCExpr *RHS, MCContext &Ctx);
358  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
359                                       MCContext &Ctx) {
360    return Create(Add, LHS, RHS, Ctx);
361  }
362  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
363                                       MCContext &Ctx) {
364    return Create(And, LHS, RHS, Ctx);
365  }
366  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
367                                       MCContext &Ctx) {
368    return Create(Div, LHS, RHS, Ctx);
369  }
370  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
371                                      MCContext &Ctx) {
372    return Create(EQ, LHS, RHS, Ctx);
373  }
374  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
375                                      MCContext &Ctx) {
376    return Create(GT, LHS, RHS, Ctx);
377  }
378  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
379                                       MCContext &Ctx) {
380    return Create(GTE, LHS, RHS, Ctx);
381  }
382  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
383                                        MCContext &Ctx) {
384    return Create(LAnd, LHS, RHS, Ctx);
385  }
386  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
387                                       MCContext &Ctx) {
388    return Create(LOr, LHS, RHS, Ctx);
389  }
390  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
391                                      MCContext &Ctx) {
392    return Create(LT, LHS, RHS, Ctx);
393  }
394  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
395                                       MCContext &Ctx) {
396    return Create(LTE, LHS, RHS, Ctx);
397  }
398  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
399                                       MCContext &Ctx) {
400    return Create(Mod, LHS, RHS, Ctx);
401  }
402  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
403                                       MCContext &Ctx) {
404    return Create(Mul, LHS, RHS, Ctx);
405  }
406  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
407                                      MCContext &Ctx) {
408    return Create(NE, LHS, RHS, Ctx);
409  }
410  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
411                                      MCContext &Ctx) {
412    return Create(Or, LHS, RHS, Ctx);
413  }
414  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
415                                       MCContext &Ctx) {
416    return Create(Shl, LHS, RHS, Ctx);
417  }
418  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
419                                       MCContext &Ctx) {
420    return Create(Shr, LHS, RHS, Ctx);
421  }
422  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
423                                       MCContext &Ctx) {
424    return Create(Sub, LHS, RHS, Ctx);
425  }
426  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
427                                       MCContext &Ctx) {
428    return Create(Xor, LHS, RHS, Ctx);
429  }
430
431  /// @}
432  /// @name Accessors
433  /// @{
434
435  /// getOpcode - Get the kind of this binary expression.
436  Opcode getOpcode() const { return Op; }
437
438  /// getLHS - Get the left-hand side expression of the binary operator.
439  const MCExpr *getLHS() const { return LHS; }
440
441  /// getRHS - Get the right-hand side expression of the binary operator.
442  const MCExpr *getRHS() const { return RHS; }
443
444  /// @}
445
446  static bool classof(const MCExpr *E) {
447    return E->getKind() == MCExpr::Binary;
448  }
449};
450
451/// MCTargetExpr - This is an extension point for target-specific MCExpr
452/// subclasses to implement.
453///
454/// NOTE: All subclasses are required to have trivial destructors because
455/// MCExprs are bump pointer allocated and not destructed.
456class MCTargetExpr : public MCExpr {
457  virtual void anchor();
458protected:
459  MCTargetExpr() : MCExpr(Target) {}
460  virtual ~MCTargetExpr() {}
461public:
462
463  virtual void PrintImpl(raw_ostream &OS) const = 0;
464  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
465                                         const MCAsmLayout *Layout) const = 0;
466  virtual void AddValueSymbols(MCAssembler *) const = 0;
467  virtual const MCSection *FindAssociatedSection() const = 0;
468
469  static bool classof(const MCExpr *E) {
470    return E->getKind() == MCExpr::Target;
471  }
472};
473
474} // end namespace llvm
475
476#endif
477