MCExpr.h revision d2849572463da994c685b3bd7a60d5a7566c01e3 
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_TOCBASE,        // symbol@tocbase
178    VK_PPC_TOC,            // symbol@toc
179    VK_PPC_TOC_LO,         // symbol@toc@l
180    VK_PPC_TOC_HA,         // symbol@toc@ha
181    VK_PPC_TPREL_LO,       // symbol@tprel@l
182    VK_PPC_TPREL_HA,       // symbol@tprel@ha
183    VK_PPC_DTPREL_LO,      // symbol@dtprel@l
184    VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
185    VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
186    VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
187    VK_PPC_TLS,            // symbol@tls
188    VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
189    VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
190    VK_PPC_TLSGD,          // symbol@tlsgd
191    VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
192    VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
193    VK_PPC_TLSLD,          // symbol@tlsld
194
195    VK_Mips_GPREL,
196    VK_Mips_GOT_CALL,
197    VK_Mips_GOT16,
198    VK_Mips_GOT,
199    VK_Mips_ABS_HI,
200    VK_Mips_ABS_LO,
201    VK_Mips_TLSGD,
202    VK_Mips_TLSLDM,
203    VK_Mips_DTPREL_HI,
204    VK_Mips_DTPREL_LO,
205    VK_Mips_GOTTPREL,
206    VK_Mips_TPREL_HI,
207    VK_Mips_TPREL_LO,
208    VK_Mips_GPOFF_HI,
209    VK_Mips_GPOFF_LO,
210    VK_Mips_GOT_DISP,
211    VK_Mips_GOT_PAGE,
212    VK_Mips_GOT_OFST,
213    VK_Mips_HIGHER,
214    VK_Mips_HIGHEST,
215    VK_Mips_GOT_HI16,
216    VK_Mips_GOT_LO16,
217    VK_Mips_CALL_HI16,
218    VK_Mips_CALL_LO16,
219
220    VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
221  };
222
223private:
224  /// The symbol being referenced.
225  const MCSymbol *Symbol;
226
227  /// The symbol reference modifier.
228  const VariantKind Kind;
229
230  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
231    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
232    assert(Symbol);
233  }
234
235public:
236  /// @name Construction
237  /// @{
238
239  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
240    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
241  }
242
243  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
244                                       MCContext &Ctx);
245  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
246                                       MCContext &Ctx);
247
248  /// @}
249  /// @name Accessors
250  /// @{
251
252  const MCSymbol &getSymbol() const { return *Symbol; }
253
254  VariantKind getKind() const { return Kind; }
255
256  /// @}
257  /// @name Static Utility Functions
258  /// @{
259
260  static StringRef getVariantKindName(VariantKind Kind);
261
262  static VariantKind getVariantKindForName(StringRef Name);
263
264  /// @}
265
266  static bool classof(const MCExpr *E) {
267    return E->getKind() == MCExpr::SymbolRef;
268  }
269};
270
271/// MCUnaryExpr - Unary assembler expressions.
272class MCUnaryExpr : public MCExpr {
273public:
274  enum Opcode {
275    LNot,  ///< Logical negation.
276    Minus, ///< Unary minus.
277    Not,   ///< Bitwise negation.
278    Plus   ///< Unary plus.
279  };
280
281private:
282  Opcode Op;
283  const MCExpr *Expr;
284
285  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
286    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
287
288public:
289  /// @name Construction
290  /// @{
291
292  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
293                                   MCContext &Ctx);
294  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
295    return Create(LNot, Expr, Ctx);
296  }
297  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
298    return Create(Minus, Expr, Ctx);
299  }
300  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
301    return Create(Not, Expr, Ctx);
302  }
303  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
304    return Create(Plus, Expr, Ctx);
305  }
306
307  /// @}
308  /// @name Accessors
309  /// @{
310
311  /// getOpcode - Get the kind of this unary expression.
312  Opcode getOpcode() const { return Op; }
313
314  /// getSubExpr - Get the child of this unary expression.
315  const MCExpr *getSubExpr() const { return Expr; }
316
317  /// @}
318
319  static bool classof(const MCExpr *E) {
320    return E->getKind() == MCExpr::Unary;
321  }
322};
323
324/// MCBinaryExpr - Binary assembler expressions.
325class MCBinaryExpr : public MCExpr {
326public:
327  enum Opcode {
328    Add,  ///< Addition.
329    And,  ///< Bitwise and.
330    Div,  ///< Signed division.
331    EQ,   ///< Equality comparison.
332    GT,   ///< Signed greater than comparison (result is either 0 or some
333          ///< target-specific non-zero value)
334    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
335          ///< some target-specific non-zero value).
336    LAnd, ///< Logical and.
337    LOr,  ///< Logical or.
338    LT,   ///< Signed less than comparison (result is either 0 or
339          ///< some target-specific non-zero value).
340    LTE,  ///< Signed less than or equal comparison (result is either 0 or
341          ///< some target-specific non-zero value).
342    Mod,  ///< Signed remainder.
343    Mul,  ///< Multiplication.
344    NE,   ///< Inequality comparison.
345    Or,   ///< Bitwise or.
346    Shl,  ///< Shift left.
347    Shr,  ///< Shift right (arithmetic or logical, depending on target)
348    Sub,  ///< Subtraction.
349    Xor   ///< Bitwise exclusive or.
350  };
351
352private:
353  Opcode Op;
354  const MCExpr *LHS, *RHS;
355
356  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
357    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
358
359public:
360  /// @name Construction
361  /// @{
362
363  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
364                                    const MCExpr *RHS, MCContext &Ctx);
365  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
366                                       MCContext &Ctx) {
367    return Create(Add, LHS, RHS, Ctx);
368  }
369  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
370                                       MCContext &Ctx) {
371    return Create(And, LHS, RHS, Ctx);
372  }
373  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
374                                       MCContext &Ctx) {
375    return Create(Div, LHS, RHS, Ctx);
376  }
377  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
378                                      MCContext &Ctx) {
379    return Create(EQ, LHS, RHS, Ctx);
380  }
381  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
382                                      MCContext &Ctx) {
383    return Create(GT, LHS, RHS, Ctx);
384  }
385  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
386                                       MCContext &Ctx) {
387    return Create(GTE, LHS, RHS, Ctx);
388  }
389  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
390                                        MCContext &Ctx) {
391    return Create(LAnd, LHS, RHS, Ctx);
392  }
393  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
394                                       MCContext &Ctx) {
395    return Create(LOr, LHS, RHS, Ctx);
396  }
397  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
398                                      MCContext &Ctx) {
399    return Create(LT, LHS, RHS, Ctx);
400  }
401  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
402                                       MCContext &Ctx) {
403    return Create(LTE, LHS, RHS, Ctx);
404  }
405  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
406                                       MCContext &Ctx) {
407    return Create(Mod, LHS, RHS, Ctx);
408  }
409  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
410                                       MCContext &Ctx) {
411    return Create(Mul, LHS, RHS, Ctx);
412  }
413  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
414                                      MCContext &Ctx) {
415    return Create(NE, LHS, RHS, Ctx);
416  }
417  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
418                                      MCContext &Ctx) {
419    return Create(Or, LHS, RHS, Ctx);
420  }
421  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
422                                       MCContext &Ctx) {
423    return Create(Shl, LHS, RHS, Ctx);
424  }
425  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
426                                       MCContext &Ctx) {
427    return Create(Shr, LHS, RHS, Ctx);
428  }
429  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
430                                       MCContext &Ctx) {
431    return Create(Sub, LHS, RHS, Ctx);
432  }
433  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
434                                       MCContext &Ctx) {
435    return Create(Xor, LHS, RHS, Ctx);
436  }
437
438  /// @}
439  /// @name Accessors
440  /// @{
441
442  /// getOpcode - Get the kind of this binary expression.
443  Opcode getOpcode() const { return Op; }
444
445  /// getLHS - Get the left-hand side expression of the binary operator.
446  const MCExpr *getLHS() const { return LHS; }
447
448  /// getRHS - Get the right-hand side expression of the binary operator.
449  const MCExpr *getRHS() const { return RHS; }
450
451  /// @}
452
453  static bool classof(const MCExpr *E) {
454    return E->getKind() == MCExpr::Binary;
455  }
456};
457
458/// MCTargetExpr - This is an extension point for target-specific MCExpr
459/// subclasses to implement.
460///
461/// NOTE: All subclasses are required to have trivial destructors because
462/// MCExprs are bump pointer allocated and not destructed.
463class MCTargetExpr : public MCExpr {
464  virtual void anchor();
465protected:
466  MCTargetExpr() : MCExpr(Target) {}
467  virtual ~MCTargetExpr() {}
468public:
469
470  virtual void PrintImpl(raw_ostream &OS) const = 0;
471  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
472                                         const MCAsmLayout *Layout) const = 0;
473  virtual void AddValueSymbols(MCAssembler *) const = 0;
474  virtual const MCSection *FindAssociatedSection() const = 0;
475
476  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
477
478  static bool classof(const MCExpr *E) {
479    return E->getKind() == MCExpr::Target;
480  }
481};
482
483} // end namespace llvm
484
485#endif
486