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 MCAsmInfo;
19class MCAsmLayout;
20class MCAssembler;
21class MCContext;
22class MCFixup;
23class MCFragment;
24class MCSection;
25class MCStreamer;
26class MCSymbol;
27class MCValue;
28class raw_ostream;
29class StringRef;
30typedef DenseMap<const MCSection *, uint64_t> SectionAddrMap;
31
32/// \brief Base class for the full range of assembler expressions which are
33/// needed for parsing.
34class MCExpr {
35public:
36  enum ExprKind {
37    Binary,    ///< Binary expressions.
38    Constant,  ///< Constant expressions.
39    SymbolRef, ///< References to labels and assigned expressions.
40    Unary,     ///< Unary expressions.
41    Target     ///< Target specific expression.
42  };
43
44private:
45  ExprKind Kind;
46
47  MCExpr(const MCExpr&) = delete;
48  void operator=(const MCExpr&) = delete;
49
50  bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
51                          const MCAsmLayout *Layout,
52                          const SectionAddrMap *Addrs) const;
53
54  bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
55                          const MCAsmLayout *Layout,
56                          const SectionAddrMap *Addrs, bool InSet) const;
57
58protected:
59  explicit MCExpr(ExprKind Kind) : Kind(Kind) {}
60
61  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
62                                 const MCAsmLayout *Layout,
63                                 const MCFixup *Fixup,
64                                 const SectionAddrMap *Addrs, bool InSet) const;
65
66public:
67  /// \name Accessors
68  /// @{
69
70  ExprKind getKind() const { return Kind; }
71
72  /// @}
73  /// \name Utility Methods
74  /// @{
75
76  void print(raw_ostream &OS, const MCAsmInfo *MAI) const;
77  void dump() const;
78
79  /// @}
80  /// \name Expression Evaluation
81  /// @{
82
83  /// \brief Try to evaluate the expression to an absolute value.
84  ///
85  /// \param Res - The absolute value, if evaluation succeeds.
86  /// \param Layout - The assembler layout object to use for evaluating symbol
87  /// values. If not given, then only non-symbolic expressions will be
88  /// evaluated.
89  /// \return - True on success.
90  bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
91                          const SectionAddrMap &Addrs) const;
92  bool evaluateAsAbsolute(int64_t &Res) const;
93  bool evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
94  bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
95
96  bool evaluateKnownAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
97
98  /// \brief Try to evaluate the expression to a relocatable value, i.e. an
99  /// expression of the fixed form (a - b + constant).
100  ///
101  /// \param Res - The relocatable value, if evaluation succeeds.
102  /// \param Layout - The assembler layout object to use for evaluating values.
103  /// \param Fixup - The Fixup object if available.
104  /// \return - True on success.
105  bool evaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout,
106                             const MCFixup *Fixup) const;
107
108  /// \brief Try to evaluate the expression to the form (a - b + constant) where
109  /// neither a nor b are variables.
110  ///
111  /// This is a more aggressive variant of evaluateAsRelocatable. The intended
112  /// use is for when relocations are not available, like the .size directive.
113  bool evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const;
114
115  /// \brief Find the "associated section" for this expression, which is
116  /// currently defined as the absolute section for constants, or
117  /// otherwise the section associated with the first defined symbol in the
118  /// expression.
119  MCFragment *findAssociatedFragment() const;
120
121  /// @}
122};
123
124inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
125  E.print(OS, nullptr);
126  return OS;
127}
128
129//// \brief  Represent a constant integer expression.
130class MCConstantExpr : public MCExpr {
131  int64_t Value;
132
133  explicit MCConstantExpr(int64_t Value)
134      : MCExpr(MCExpr::Constant), Value(Value) {}
135
136public:
137  /// \name Construction
138  /// @{
139
140  static const MCConstantExpr *create(int64_t Value, MCContext &Ctx);
141
142  /// @}
143  /// \name Accessors
144  /// @{
145
146  int64_t getValue() const { return Value; }
147
148  /// @}
149
150  static bool classof(const MCExpr *E) {
151    return E->getKind() == MCExpr::Constant;
152  }
153};
154
155/// \brief  Represent a reference to a symbol from inside an expression.
156///
157/// A symbol reference in an expression may be a use of a label, a use of an
158/// assembler variable (defined constant), or constitute an implicit definition
159/// of the symbol as external.
160class MCSymbolRefExpr : public MCExpr {
161public:
162  enum VariantKind : uint16_t {
163    VK_None,
164    VK_Invalid,
165
166    VK_GOT,
167    VK_GOTOFF,
168    VK_GOTPCREL,
169    VK_GOTTPOFF,
170    VK_INDNTPOFF,
171    VK_NTPOFF,
172    VK_GOTNTPOFF,
173    VK_PLT,
174    VK_TLSGD,
175    VK_TLSLD,
176    VK_TLSLDM,
177    VK_TPOFF,
178    VK_DTPOFF,
179    VK_TLVP,      // Mach-O thread local variable relocations
180    VK_TLVPPAGE,
181    VK_TLVPPAGEOFF,
182    VK_PAGE,
183    VK_PAGEOFF,
184    VK_GOTPAGE,
185    VK_GOTPAGEOFF,
186    VK_SECREL,
187    VK_SIZE,      // symbol@SIZE
188    VK_WEAKREF,   // The link between the symbols in .weakref foo, bar
189
190    VK_ARM_NONE,
191    VK_ARM_GOT_PREL,
192    VK_ARM_TARGET1,
193    VK_ARM_TARGET2,
194    VK_ARM_PREL31,
195    VK_ARM_SBREL,          // symbol(sbrel)
196    VK_ARM_TLSLDO,         // symbol(tlsldo)
197    VK_ARM_TLSCALL,        // symbol(tlscall)
198    VK_ARM_TLSDESC,        // symbol(tlsdesc)
199    VK_ARM_TLSDESCSEQ,
200
201    VK_PPC_LO,             // symbol@l
202    VK_PPC_HI,             // symbol@h
203    VK_PPC_HA,             // symbol@ha
204    VK_PPC_HIGHER,         // symbol@higher
205    VK_PPC_HIGHERA,        // symbol@highera
206    VK_PPC_HIGHEST,        // symbol@highest
207    VK_PPC_HIGHESTA,       // symbol@highesta
208    VK_PPC_GOT_LO,         // symbol@got@l
209    VK_PPC_GOT_HI,         // symbol@got@h
210    VK_PPC_GOT_HA,         // symbol@got@ha
211    VK_PPC_TOCBASE,        // symbol@tocbase
212    VK_PPC_TOC,            // symbol@toc
213    VK_PPC_TOC_LO,         // symbol@toc@l
214    VK_PPC_TOC_HI,         // symbol@toc@h
215    VK_PPC_TOC_HA,         // symbol@toc@ha
216    VK_PPC_DTPMOD,         // symbol@dtpmod
217    VK_PPC_TPREL,          // symbol@tprel
218    VK_PPC_TPREL_LO,       // symbol@tprel@l
219    VK_PPC_TPREL_HI,       // symbol@tprel@h
220    VK_PPC_TPREL_HA,       // symbol@tprel@ha
221    VK_PPC_TPREL_HIGHER,   // symbol@tprel@higher
222    VK_PPC_TPREL_HIGHERA,  // symbol@tprel@highera
223    VK_PPC_TPREL_HIGHEST,  // symbol@tprel@highest
224    VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
225    VK_PPC_DTPREL,         // symbol@dtprel
226    VK_PPC_DTPREL_LO,      // symbol@dtprel@l
227    VK_PPC_DTPREL_HI,      // symbol@dtprel@h
228    VK_PPC_DTPREL_HA,      // symbol@dtprel@ha
229    VK_PPC_DTPREL_HIGHER,  // symbol@dtprel@higher
230    VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
231    VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
232    VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
233    VK_PPC_GOT_TPREL,      // symbol@got@tprel
234    VK_PPC_GOT_TPREL_LO,   // symbol@got@tprel@l
235    VK_PPC_GOT_TPREL_HI,   // symbol@got@tprel@h
236    VK_PPC_GOT_TPREL_HA,   // symbol@got@tprel@ha
237    VK_PPC_GOT_DTPREL,     // symbol@got@dtprel
238    VK_PPC_GOT_DTPREL_LO,  // symbol@got@dtprel@l
239    VK_PPC_GOT_DTPREL_HI,  // symbol@got@dtprel@h
240    VK_PPC_GOT_DTPREL_HA,  // symbol@got@dtprel@ha
241    VK_PPC_TLS,            // symbol@tls
242    VK_PPC_GOT_TLSGD,      // symbol@got@tlsgd
243    VK_PPC_GOT_TLSGD_LO,   // symbol@got@tlsgd@l
244    VK_PPC_GOT_TLSGD_HI,   // symbol@got@tlsgd@h
245    VK_PPC_GOT_TLSGD_HA,   // symbol@got@tlsgd@ha
246    VK_PPC_TLSGD,          // symbol@tlsgd
247    VK_PPC_GOT_TLSLD,      // symbol@got@tlsld
248    VK_PPC_GOT_TLSLD_LO,   // symbol@got@tlsld@l
249    VK_PPC_GOT_TLSLD_HI,   // symbol@got@tlsld@h
250    VK_PPC_GOT_TLSLD_HA,   // symbol@got@tlsld@ha
251    VK_PPC_TLSLD,          // symbol@tlsld
252    VK_PPC_LOCAL,          // symbol@local
253
254    VK_Mips_GPREL,
255    VK_Mips_GOT_CALL,
256    VK_Mips_GOT16,
257    VK_Mips_GOT,
258    VK_Mips_ABS_HI,
259    VK_Mips_ABS_LO,
260    VK_Mips_TLSGD,
261    VK_Mips_TLSLDM,
262    VK_Mips_DTPREL_HI,
263    VK_Mips_DTPREL_LO,
264    VK_Mips_GOTTPREL,
265    VK_Mips_TPREL_HI,
266    VK_Mips_TPREL_LO,
267    VK_Mips_GPOFF_HI,
268    VK_Mips_GPOFF_LO,
269    VK_Mips_GOT_DISP,
270    VK_Mips_GOT_PAGE,
271    VK_Mips_GOT_OFST,
272    VK_Mips_HIGHER,
273    VK_Mips_HIGHEST,
274    VK_Mips_GOT_HI16,
275    VK_Mips_GOT_LO16,
276    VK_Mips_CALL_HI16,
277    VK_Mips_CALL_LO16,
278    VK_Mips_PCREL_HI16,
279    VK_Mips_PCREL_LO16,
280
281    VK_COFF_IMGREL32, // symbol@imgrel (image-relative)
282
283    VK_Hexagon_PCREL,
284    VK_Hexagon_LO16,
285    VK_Hexagon_HI16,
286    VK_Hexagon_GPREL,
287    VK_Hexagon_GD_GOT,
288    VK_Hexagon_LD_GOT,
289    VK_Hexagon_GD_PLT,
290    VK_Hexagon_LD_PLT,
291    VK_Hexagon_IE,
292    VK_Hexagon_IE_GOT,
293    VK_TPREL,
294    VK_DTPREL
295  };
296
297private:
298  /// The symbol reference modifier.
299  const VariantKind Kind;
300
301  /// Specifies how the variant kind should be printed.
302  const unsigned UseParensForSymbolVariant : 1;
303
304  // FIXME: Remove this bit.
305  const unsigned HasSubsectionsViaSymbols : 1;
306
307  /// The symbol being referenced.
308  const MCSymbol *Symbol;
309
310  explicit MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
311                           const MCAsmInfo *MAI);
312
313public:
314  /// \name Construction
315  /// @{
316
317  static const MCSymbolRefExpr *create(const MCSymbol *Symbol, MCContext &Ctx) {
318    return MCSymbolRefExpr::create(Symbol, VK_None, Ctx);
319  }
320
321  static const MCSymbolRefExpr *create(const MCSymbol *Symbol, VariantKind Kind,
322                                       MCContext &Ctx);
323  static const MCSymbolRefExpr *create(StringRef Name, VariantKind Kind,
324                                       MCContext &Ctx);
325
326  /// @}
327  /// \name Accessors
328  /// @{
329
330  const MCSymbol &getSymbol() const { return *Symbol; }
331
332  VariantKind getKind() const { return Kind; }
333
334  void printVariantKind(raw_ostream &OS) const;
335
336  bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
337
338  /// @}
339  /// \name Static Utility Functions
340  /// @{
341
342  static StringRef getVariantKindName(VariantKind Kind);
343
344  static VariantKind getVariantKindForName(StringRef Name);
345
346  /// @}
347
348  static bool classof(const MCExpr *E) {
349    return E->getKind() == MCExpr::SymbolRef;
350  }
351};
352
353/// \brief Unary assembler expressions.
354class MCUnaryExpr : public MCExpr {
355public:
356  enum Opcode {
357    LNot,  ///< Logical negation.
358    Minus, ///< Unary minus.
359    Not,   ///< Bitwise negation.
360    Plus   ///< Unary plus.
361  };
362
363private:
364  Opcode Op;
365  const MCExpr *Expr;
366
367  MCUnaryExpr(Opcode Op, const MCExpr *Expr)
368      : MCExpr(MCExpr::Unary), Op(Op), Expr(Expr) {}
369
370public:
371  /// \name Construction
372  /// @{
373
374  static const MCUnaryExpr *create(Opcode Op, const MCExpr *Expr,
375                                   MCContext &Ctx);
376  static const MCUnaryExpr *createLNot(const MCExpr *Expr, MCContext &Ctx) {
377    return create(LNot, Expr, Ctx);
378  }
379  static const MCUnaryExpr *createMinus(const MCExpr *Expr, MCContext &Ctx) {
380    return create(Minus, Expr, Ctx);
381  }
382  static const MCUnaryExpr *createNot(const MCExpr *Expr, MCContext &Ctx) {
383    return create(Not, Expr, Ctx);
384  }
385  static const MCUnaryExpr *createPlus(const MCExpr *Expr, MCContext &Ctx) {
386    return create(Plus, Expr, Ctx);
387  }
388
389  /// @}
390  /// \name Accessors
391  /// @{
392
393  /// \brief Get the kind of this unary expression.
394  Opcode getOpcode() const { return Op; }
395
396  /// \brief Get the child of this unary expression.
397  const MCExpr *getSubExpr() const { return Expr; }
398
399  /// @}
400
401  static bool classof(const MCExpr *E) {
402    return E->getKind() == MCExpr::Unary;
403  }
404};
405
406/// \brief Binary assembler expressions.
407class MCBinaryExpr : public MCExpr {
408public:
409  enum Opcode {
410    Add,  ///< Addition.
411    And,  ///< Bitwise and.
412    Div,  ///< Signed division.
413    EQ,   ///< Equality comparison.
414    GT,   ///< Signed greater than comparison (result is either 0 or some
415          ///< target-specific non-zero value)
416    GTE,  ///< Signed greater than or equal comparison (result is either 0 or
417          ///< some target-specific non-zero value).
418    LAnd, ///< Logical and.
419    LOr,  ///< Logical or.
420    LT,   ///< Signed less than comparison (result is either 0 or
421          ///< some target-specific non-zero value).
422    LTE,  ///< Signed less than or equal comparison (result is either 0 or
423          ///< some target-specific non-zero value).
424    Mod,  ///< Signed remainder.
425    Mul,  ///< Multiplication.
426    NE,   ///< Inequality comparison.
427    Or,   ///< Bitwise or.
428    Shl,  ///< Shift left.
429    AShr, ///< Arithmetic shift right.
430    LShr, ///< Logical shift right.
431    Sub,  ///< Subtraction.
432    Xor   ///< Bitwise exclusive or.
433  };
434
435private:
436  Opcode Op;
437  const MCExpr *LHS, *RHS;
438
439  MCBinaryExpr(Opcode Op, const MCExpr *LHS, const MCExpr *RHS)
440      : MCExpr(MCExpr::Binary), Op(Op), LHS(LHS), RHS(RHS) {}
441
442public:
443  /// \name Construction
444  /// @{
445
446  static const MCBinaryExpr *create(Opcode Op, const MCExpr *LHS,
447                                    const MCExpr *RHS, MCContext &Ctx);
448  static const MCBinaryExpr *createAdd(const MCExpr *LHS, const MCExpr *RHS,
449                                       MCContext &Ctx) {
450    return create(Add, LHS, RHS, Ctx);
451  }
452  static const MCBinaryExpr *createAnd(const MCExpr *LHS, const MCExpr *RHS,
453                                       MCContext &Ctx) {
454    return create(And, LHS, RHS, Ctx);
455  }
456  static const MCBinaryExpr *createDiv(const MCExpr *LHS, const MCExpr *RHS,
457                                       MCContext &Ctx) {
458    return create(Div, LHS, RHS, Ctx);
459  }
460  static const MCBinaryExpr *createEQ(const MCExpr *LHS, const MCExpr *RHS,
461                                      MCContext &Ctx) {
462    return create(EQ, LHS, RHS, Ctx);
463  }
464  static const MCBinaryExpr *createGT(const MCExpr *LHS, const MCExpr *RHS,
465                                      MCContext &Ctx) {
466    return create(GT, LHS, RHS, Ctx);
467  }
468  static const MCBinaryExpr *createGTE(const MCExpr *LHS, const MCExpr *RHS,
469                                       MCContext &Ctx) {
470    return create(GTE, LHS, RHS, Ctx);
471  }
472  static const MCBinaryExpr *createLAnd(const MCExpr *LHS, const MCExpr *RHS,
473                                        MCContext &Ctx) {
474    return create(LAnd, LHS, RHS, Ctx);
475  }
476  static const MCBinaryExpr *createLOr(const MCExpr *LHS, const MCExpr *RHS,
477                                       MCContext &Ctx) {
478    return create(LOr, LHS, RHS, Ctx);
479  }
480  static const MCBinaryExpr *createLT(const MCExpr *LHS, const MCExpr *RHS,
481                                      MCContext &Ctx) {
482    return create(LT, LHS, RHS, Ctx);
483  }
484  static const MCBinaryExpr *createLTE(const MCExpr *LHS, const MCExpr *RHS,
485                                       MCContext &Ctx) {
486    return create(LTE, LHS, RHS, Ctx);
487  }
488  static const MCBinaryExpr *createMod(const MCExpr *LHS, const MCExpr *RHS,
489                                       MCContext &Ctx) {
490    return create(Mod, LHS, RHS, Ctx);
491  }
492  static const MCBinaryExpr *createMul(const MCExpr *LHS, const MCExpr *RHS,
493                                       MCContext &Ctx) {
494    return create(Mul, LHS, RHS, Ctx);
495  }
496  static const MCBinaryExpr *createNE(const MCExpr *LHS, const MCExpr *RHS,
497                                      MCContext &Ctx) {
498    return create(NE, LHS, RHS, Ctx);
499  }
500  static const MCBinaryExpr *createOr(const MCExpr *LHS, const MCExpr *RHS,
501                                      MCContext &Ctx) {
502    return create(Or, LHS, RHS, Ctx);
503  }
504  static const MCBinaryExpr *createShl(const MCExpr *LHS, const MCExpr *RHS,
505                                       MCContext &Ctx) {
506    return create(Shl, LHS, RHS, Ctx);
507  }
508  static const MCBinaryExpr *createAShr(const MCExpr *LHS, const MCExpr *RHS,
509                                       MCContext &Ctx) {
510    return create(AShr, LHS, RHS, Ctx);
511  }
512  static const MCBinaryExpr *createLShr(const MCExpr *LHS, const MCExpr *RHS,
513                                       MCContext &Ctx) {
514    return create(LShr, LHS, RHS, Ctx);
515  }
516  static const MCBinaryExpr *createSub(const MCExpr *LHS, const MCExpr *RHS,
517                                       MCContext &Ctx) {
518    return create(Sub, LHS, RHS, Ctx);
519  }
520  static const MCBinaryExpr *createXor(const MCExpr *LHS, const MCExpr *RHS,
521                                       MCContext &Ctx) {
522    return create(Xor, LHS, RHS, Ctx);
523  }
524
525  /// @}
526  /// \name Accessors
527  /// @{
528
529  /// \brief Get the kind of this binary expression.
530  Opcode getOpcode() const { return Op; }
531
532  /// \brief Get the left-hand side expression of the binary operator.
533  const MCExpr *getLHS() const { return LHS; }
534
535  /// \brief Get the right-hand side expression of the binary operator.
536  const MCExpr *getRHS() const { return RHS; }
537
538  /// @}
539
540  static bool classof(const MCExpr *E) {
541    return E->getKind() == MCExpr::Binary;
542  }
543};
544
545/// \brief This is an extension point for target-specific MCExpr subclasses to
546/// implement.
547///
548/// NOTE: All subclasses are required to have trivial destructors because
549/// MCExprs are bump pointer allocated and not destructed.
550class MCTargetExpr : public MCExpr {
551  virtual void anchor();
552protected:
553  MCTargetExpr() : MCExpr(Target) {}
554  virtual ~MCTargetExpr() {}
555public:
556  virtual void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const = 0;
557  virtual bool evaluateAsRelocatableImpl(MCValue &Res,
558                                         const MCAsmLayout *Layout,
559                                         const MCFixup *Fixup) const = 0;
560  virtual void visitUsedExpr(MCStreamer& Streamer) const = 0;
561  virtual MCFragment *findAssociatedFragment() const = 0;
562
563  virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
564
565  static bool classof(const MCExpr *E) {
566    return E->getKind() == MCExpr::Target;
567  }
568};
569
570} // end namespace llvm
571
572#endif
573