MCExpr.h revision 18d49acdab79d6f0966b47182b6c3a2ba3d9f80f 
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_DTPREL16_HA,  // symbol@dtprel@ha
183    VK_PPC_DTPREL16_LO,  // symbol@dtprel@l
184    VK_PPC_TOC16_HA,     // symbol@toc@ha
185    VK_PPC_TOC16_LO,     // symbol@toc@l
186    VK_PPC_GOT_TPREL16_HA, // symbol@got@tprel@ha
187    VK_PPC_GOT_TPREL16_LO, // symbol@got@tprel@l
188    VK_PPC_TLS,            // symbol@tls
189    VK_PPC_GOT_TLSGD16_HA, // symbol@got@tlsgd@ha
190    VK_PPC_GOT_TLSGD16_LO, // symbol@got@tlsgd@l
191    VK_PPC_TLSGD,          // symbol@tlsgd
192    VK_PPC_GOT_TLSLD16_HA, // symbol@got@tlsld@ha
193    VK_PPC_GOT_TLSLD16_LO, // symbol@got@tlsld@l
194    VK_PPC_TLSLD,          // symbol@tlsld
195
196    VK_Mips_GPREL,
197    VK_Mips_GOT_CALL,
198    VK_Mips_GOT16,
199    VK_Mips_GOT,
200    VK_Mips_ABS_HI,
201    VK_Mips_ABS_LO,
202    VK_Mips_TLSGD,
203    VK_Mips_TLSLDM,
204    VK_Mips_DTPREL_HI,
205    VK_Mips_DTPREL_LO,
206    VK_Mips_GOTTPREL,
207    VK_Mips_TPREL_HI,
208    VK_Mips_TPREL_LO,
209    VK_Mips_GPOFF_HI,
210    VK_Mips_GPOFF_LO,
211    VK_Mips_GOT_DISP,
212    VK_Mips_GOT_PAGE,
213    VK_Mips_GOT_OFST,
214    VK_Mips_HIGHER,
215    VK_Mips_HIGHEST,
216    VK_Mips_GOT_HI16,
217    VK_Mips_GOT_LO16,
218    VK_Mips_CALL_HI16,
219    VK_Mips_CALL_LO16,
220
221    VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
222  };
223
224private:
225  /// The symbol being referenced.
226  const MCSymbol *Symbol;
227
228  /// The symbol reference modifier.
229  const VariantKind Kind;
230
231  explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
232    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {
233    assert(Symbol);
234  }
235
236public:
237  /// @name Construction
238  /// @{
239
240  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
241    return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
242  }
243
244  static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
245                                       MCContext &Ctx);
246  static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
247                                       MCContext &Ctx);
248
249  /// @}
250  /// @name Accessors
251  /// @{
252
253  const MCSymbol &getSymbol() const { return *Symbol; }
254
255  VariantKind getKind() const { return Kind; }
256
257  /// @}
258  /// @name Static Utility Functions
259  /// @{
260
261  static StringRef getVariantKindName(VariantKind Kind);
262
263  static VariantKind getVariantKindForName(StringRef Name);
264
265  /// @}
266
267  static bool classof(const MCExpr *E) {
268    return E->getKind() == MCExpr::SymbolRef;
269  }
270};
271
272/// MCUnaryExpr - Unary assembler expressions.
273class MCUnaryExpr : public MCExpr {
274public:
275  enum Opcode {
276    LNot,  ///< Logical negation.
277    Minus, ///< Unary minus.
278    Not,   ///< Bitwise negation.
279    Plus   ///< Unary plus.
280  };
281
282private:
283  Opcode Op;
284  const MCExpr *Expr;
285
286  MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
287    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
288
289public:
290  /// @name Construction
291  /// @{
292
293  static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
294                                   MCContext &Ctx);
295  static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
296    return Create(LNot, Expr, Ctx);
297  }
298  static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
299    return Create(Minus, Expr, Ctx);
300  }
301  static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
302    return Create(Not, Expr, Ctx);
303  }
304  static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
305    return Create(Plus, Expr, Ctx);
306  }
307
308  /// @}
309  /// @name Accessors
310  /// @{
311
312  /// getOpcode - Get the kind of this unary expression.
313  Opcode getOpcode() const { return Op; }
314
315  /// getSubExpr - Get the child of this unary expression.
316  const MCExpr *getSubExpr() const { return Expr; }
317
318  /// @}
319
320  static bool classof(const MCExpr *E) {
321    return E->getKind() == MCExpr::Unary;
322  }
323};
324
325/// MCBinaryExpr - Binary assembler expressions.
326class MCBinaryExpr : public MCExpr {
327public:
328  enum Opcode {
329    Add,  ///< Addition.
330    And,  ///< Bitwise and.
331    Div,  ///< Signed division.
332    EQ,   ///< Equality comparison.
333    GT,   ///< Signed greater than comparison (result is either 0 or some
334          ///< target-specific non-zero value)
335    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
336          ///< some target-specific non-zero value).
337    LAnd, ///< Logical and.
338    LOr,  ///< Logical or.
339    LT,   ///< Signed less than comparison (result is either 0 or
340          ///< some target-specific non-zero value).
341    LTE,  ///< Signed less than or equal comparison (result is either 0 or
342          ///< some target-specific non-zero value).
343    Mod,  ///< Signed remainder.
344    Mul,  ///< Multiplication.
345    NE,   ///< Inequality comparison.
346    Or,   ///< Bitwise or.
347    Shl,  ///< Shift left.
348    Shr,  ///< Shift right (arithmetic or logical, depending on target)
349    Sub,  ///< Subtraction.
350    Xor   ///< Bitwise exclusive or.
351  };
352
353private:
354  Opcode Op;
355  const MCExpr *LHS, *RHS;
356
357  MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
358    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
359
360public:
361  /// @name Construction
362  /// @{
363
364  static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
365                                    const MCExpr *RHS, MCContext &Ctx);
366  static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
367                                       MCContext &Ctx) {
368    return Create(Add, LHS, RHS, Ctx);
369  }
370  static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
371                                       MCContext &Ctx) {
372    return Create(And, LHS, RHS, Ctx);
373  }
374  static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
375                                       MCContext &Ctx) {
376    return Create(Div, LHS, RHS, Ctx);
377  }
378  static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
379                                      MCContext &Ctx) {
380    return Create(EQ, LHS, RHS, Ctx);
381  }
382  static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
383                                      MCContext &Ctx) {
384    return Create(GT, LHS, RHS, Ctx);
385  }
386  static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
387                                       MCContext &Ctx) {
388    return Create(GTE, LHS, RHS, Ctx);
389  }
390  static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
391                                        MCContext &Ctx) {
392    return Create(LAnd, LHS, RHS, Ctx);
393  }
394  static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
395                                       MCContext &Ctx) {
396    return Create(LOr, LHS, RHS, Ctx);
397  }
398  static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
399                                      MCContext &Ctx) {
400    return Create(LT, LHS, RHS, Ctx);
401  }
402  static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
403                                       MCContext &Ctx) {
404    return Create(LTE, LHS, RHS, Ctx);
405  }
406  static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
407                                       MCContext &Ctx) {
408    return Create(Mod, LHS, RHS, Ctx);
409  }
410  static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
411                                       MCContext &Ctx) {
412    return Create(Mul, LHS, RHS, Ctx);
413  }
414  static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
415                                      MCContext &Ctx) {
416    return Create(NE, LHS, RHS, Ctx);
417  }
418  static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
419                                      MCContext &Ctx) {
420    return Create(Or, LHS, RHS, Ctx);
421  }
422  static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
423                                       MCContext &Ctx) {
424    return Create(Shl, LHS, RHS, Ctx);
425  }
426  static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
427                                       MCContext &Ctx) {
428    return Create(Shr, LHS, RHS, Ctx);
429  }
430  static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
431                                       MCContext &Ctx) {
432    return Create(Sub, LHS, RHS, Ctx);
433  }
434  static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
435                                       MCContext &Ctx) {
436    return Create(Xor, LHS, RHS, Ctx);
437  }
438
439  /// @}
440  /// @name Accessors
441  /// @{
442
443  /// getOpcode - Get the kind of this binary expression.
444  Opcode getOpcode() const { return Op; }
445
446  /// getLHS - Get the left-hand side expression of the binary operator.
447  const MCExpr *getLHS() const { return LHS; }
448
449  /// getRHS - Get the right-hand side expression of the binary operator.
450  const MCExpr *getRHS() const { return RHS; }
451
452  /// @}
453
454  static bool classof(const MCExpr *E) {
455    return E->getKind() == MCExpr::Binary;
456  }
457};
458
459/// MCTargetExpr - This is an extension point for target-specific MCExpr
460/// subclasses to implement.
461///
462/// NOTE: All subclasses are required to have trivial destructors because
463/// MCExprs are bump pointer allocated and not destructed.
464class MCTargetExpr : public MCExpr {
465  virtual void anchor();
466protected:
467  MCTargetExpr() : MCExpr(Target) {}
468  virtual ~MCTargetExpr() {}
469public:
470
471  virtual void PrintImpl(raw_ostream &OS) const = 0;
472  virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
473                                         const MCAsmLayout *Layout) const = 0;
474  virtual void AddValueSymbols(MCAssembler *) const = 0;
475  virtual const MCSection *FindAssociatedSection() const = 0;
476
477  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
478
479  static bool classof(const MCExpr *E) {
480    return E->getKind() == MCExpr::Target;
481  }
482};
483
484} // end namespace llvm
485
486#endif
487