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/SMLoc.h" 15 #include <cstdint> 16 17 namespace llvm { 18 19 class MCAsmInfo; 20 class MCAsmLayout; 21 class MCAssembler; 22 class MCContext; 23 class MCFixup; 24 class MCFragment; 25 class MCSection; 26 class MCStreamer; 27 class MCSymbol; 28 class MCValue; 29 class raw_ostream; 30 class StringRef; 31 32 using SectionAddrMap = DenseMap<const MCSection *, uint64_t>; 33 34 /// Base class for the full range of assembler expressions which are 35 /// needed for parsing. 36 class MCExpr { 37 public: 38 enum ExprKind { 39 Binary, ///< Binary expressions. 40 Constant, ///< Constant expressions. 41 SymbolRef, ///< References to labels and assigned expressions. 42 Unary, ///< Unary expressions. 43 Target ///< Target specific expression. 44 }; 45 46 private: 47 ExprKind Kind; 48 SMLoc Loc; 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 58 protected: MCExpr(ExprKind Kind,SMLoc Loc)59 explicit MCExpr(ExprKind Kind, SMLoc Loc) : Kind(Kind), Loc(Loc) {} 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 66 public: 67 MCExpr(const MCExpr &) = delete; 68 MCExpr &operator=(const MCExpr &) = delete; 69 70 /// \name Accessors 71 /// @{ 72 getKind()73 ExprKind getKind() const { return Kind; } getLoc()74 SMLoc getLoc() const { return Loc; } 75 76 /// @} 77 /// \name Utility Methods 78 /// @{ 79 80 void print(raw_ostream &OS, const MCAsmInfo *MAI, 81 bool InParens = false) const; 82 void dump() const; 83 84 /// @} 85 /// \name Expression Evaluation 86 /// @{ 87 88 /// Try to evaluate the expression to an absolute value. 89 /// 90 /// \param Res - The absolute value, if evaluation succeeds. 91 /// \param Layout - The assembler layout object to use for evaluating symbol 92 /// values. If not given, then only non-symbolic expressions will be 93 /// evaluated. 94 /// \return - True on success. 95 bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout, 96 const SectionAddrMap &Addrs) const; 97 bool evaluateAsAbsolute(int64_t &Res) const; 98 bool evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const; 99 bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const; 100 bool evaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const; 101 102 bool evaluateKnownAbsolute(int64_t &Res, const MCAsmLayout &Layout) const; 103 104 /// Try to evaluate the expression to a relocatable value, i.e. an 105 /// expression of the fixed form (a - b + constant). 106 /// 107 /// \param Res - The relocatable value, if evaluation succeeds. 108 /// \param Layout - The assembler layout object to use for evaluating values. 109 /// \param Fixup - The Fixup object if available. 110 /// \return - True on success. 111 bool evaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout, 112 const MCFixup *Fixup) const; 113 114 /// Try to evaluate the expression to the form (a - b + constant) where 115 /// neither a nor b are variables. 116 /// 117 /// This is a more aggressive variant of evaluateAsRelocatable. The intended 118 /// use is for when relocations are not available, like the .size directive. 119 bool evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const; 120 121 /// Find the "associated section" for this expression, which is 122 /// currently defined as the absolute section for constants, or 123 /// otherwise the section associated with the first defined symbol in the 124 /// expression. 125 MCFragment *findAssociatedFragment() const; 126 127 /// @} 128 }; 129 130 inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) { 131 E.print(OS, nullptr); 132 return OS; 133 } 134 135 //// Represent a constant integer expression. 136 class MCConstantExpr : public MCExpr { 137 int64_t Value; 138 MCConstantExpr(int64_t Value)139 explicit MCConstantExpr(int64_t Value) 140 : MCExpr(MCExpr::Constant, SMLoc()), Value(Value) {} 141 142 public: 143 /// \name Construction 144 /// @{ 145 146 static const MCConstantExpr *create(int64_t Value, MCContext &Ctx); 147 148 /// @} 149 /// \name Accessors 150 /// @{ 151 getValue()152 int64_t getValue() const { return Value; } 153 154 /// @} 155 classof(const MCExpr * E)156 static bool classof(const MCExpr *E) { 157 return E->getKind() == MCExpr::Constant; 158 } 159 }; 160 161 /// Represent a reference to a symbol from inside an expression. 162 /// 163 /// A symbol reference in an expression may be a use of a label, a use of an 164 /// assembler variable (defined constant), or constitute an implicit definition 165 /// of the symbol as external. 166 class MCSymbolRefExpr : public MCExpr { 167 public: 168 enum VariantKind : uint16_t { 169 VK_None, 170 VK_Invalid, 171 172 VK_GOT, 173 VK_GOTOFF, 174 VK_GOTREL, 175 VK_GOTPCREL, 176 VK_GOTTPOFF, 177 VK_INDNTPOFF, 178 VK_NTPOFF, 179 VK_GOTNTPOFF, 180 VK_PLT, 181 VK_TLSGD, 182 VK_TLSLD, 183 VK_TLSLDM, 184 VK_TPOFF, 185 VK_DTPOFF, 186 VK_TLSCALL, // symbol(tlscall) 187 VK_TLSDESC, // symbol(tlsdesc) 188 VK_TLVP, // Mach-O thread local variable relocations 189 VK_TLVPPAGE, 190 VK_TLVPPAGEOFF, 191 VK_PAGE, 192 VK_PAGEOFF, 193 VK_GOTPAGE, 194 VK_GOTPAGEOFF, 195 VK_SECREL, 196 VK_SIZE, // symbol@SIZE 197 VK_WEAKREF, // The link between the symbols in .weakref foo, bar 198 199 VK_X86_ABS8, 200 201 VK_ARM_NONE, 202 VK_ARM_GOT_PREL, 203 VK_ARM_TARGET1, 204 VK_ARM_TARGET2, 205 VK_ARM_PREL31, 206 VK_ARM_SBREL, // symbol(sbrel) 207 VK_ARM_TLSLDO, // symbol(tlsldo) 208 VK_ARM_TLSDESCSEQ, 209 210 VK_AVR_NONE, 211 VK_AVR_LO8, 212 VK_AVR_HI8, 213 VK_AVR_HLO8, 214 VK_AVR_DIFF8, 215 VK_AVR_DIFF16, 216 VK_AVR_DIFF32, 217 218 VK_PPC_LO, // symbol@l 219 VK_PPC_HI, // symbol@h 220 VK_PPC_HA, // symbol@ha 221 VK_PPC_HIGH, // symbol@high 222 VK_PPC_HIGHA, // symbol@higha 223 VK_PPC_HIGHER, // symbol@higher 224 VK_PPC_HIGHERA, // symbol@highera 225 VK_PPC_HIGHEST, // symbol@highest 226 VK_PPC_HIGHESTA, // symbol@highesta 227 VK_PPC_GOT_LO, // symbol@got@l 228 VK_PPC_GOT_HI, // symbol@got@h 229 VK_PPC_GOT_HA, // symbol@got@ha 230 VK_PPC_TOCBASE, // symbol@tocbase 231 VK_PPC_TOC, // symbol@toc 232 VK_PPC_TOC_LO, // symbol@toc@l 233 VK_PPC_TOC_HI, // symbol@toc@h 234 VK_PPC_TOC_HA, // symbol@toc@ha 235 VK_PPC_DTPMOD, // symbol@dtpmod 236 VK_PPC_TPREL_LO, // symbol@tprel@l 237 VK_PPC_TPREL_HI, // symbol@tprel@h 238 VK_PPC_TPREL_HA, // symbol@tprel@ha 239 VK_PPC_TPREL_HIGH, // symbol@tprel@high 240 VK_PPC_TPREL_HIGHA, // symbol@tprel@higha 241 VK_PPC_TPREL_HIGHER, // symbol@tprel@higher 242 VK_PPC_TPREL_HIGHERA, // symbol@tprel@highera 243 VK_PPC_TPREL_HIGHEST, // symbol@tprel@highest 244 VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta 245 VK_PPC_DTPREL_LO, // symbol@dtprel@l 246 VK_PPC_DTPREL_HI, // symbol@dtprel@h 247 VK_PPC_DTPREL_HA, // symbol@dtprel@ha 248 VK_PPC_DTPREL_HIGH, // symbol@dtprel@high 249 VK_PPC_DTPREL_HIGHA, // symbol@dtprel@higha 250 VK_PPC_DTPREL_HIGHER, // symbol@dtprel@higher 251 VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera 252 VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest 253 VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta 254 VK_PPC_GOT_TPREL, // symbol@got@tprel 255 VK_PPC_GOT_TPREL_LO, // symbol@got@tprel@l 256 VK_PPC_GOT_TPREL_HI, // symbol@got@tprel@h 257 VK_PPC_GOT_TPREL_HA, // symbol@got@tprel@ha 258 VK_PPC_GOT_DTPREL, // symbol@got@dtprel 259 VK_PPC_GOT_DTPREL_LO, // symbol@got@dtprel@l 260 VK_PPC_GOT_DTPREL_HI, // symbol@got@dtprel@h 261 VK_PPC_GOT_DTPREL_HA, // symbol@got@dtprel@ha 262 VK_PPC_TLS, // symbol@tls 263 VK_PPC_GOT_TLSGD, // symbol@got@tlsgd 264 VK_PPC_GOT_TLSGD_LO, // symbol@got@tlsgd@l 265 VK_PPC_GOT_TLSGD_HI, // symbol@got@tlsgd@h 266 VK_PPC_GOT_TLSGD_HA, // symbol@got@tlsgd@ha 267 VK_PPC_TLSGD, // symbol@tlsgd 268 VK_PPC_GOT_TLSLD, // symbol@got@tlsld 269 VK_PPC_GOT_TLSLD_LO, // symbol@got@tlsld@l 270 VK_PPC_GOT_TLSLD_HI, // symbol@got@tlsld@h 271 VK_PPC_GOT_TLSLD_HA, // symbol@got@tlsld@ha 272 VK_PPC_TLSLD, // symbol@tlsld 273 VK_PPC_LOCAL, // symbol@local 274 275 VK_COFF_IMGREL32, // symbol@imgrel (image-relative) 276 277 VK_Hexagon_PCREL, 278 VK_Hexagon_LO16, 279 VK_Hexagon_HI16, 280 VK_Hexagon_GPREL, 281 VK_Hexagon_GD_GOT, 282 VK_Hexagon_LD_GOT, 283 VK_Hexagon_GD_PLT, 284 VK_Hexagon_LD_PLT, 285 VK_Hexagon_IE, 286 VK_Hexagon_IE_GOT, 287 288 VK_WebAssembly_FUNCTION, // Function table index, rather than virtual addr 289 VK_WebAssembly_TYPEINDEX,// Type table index 290 291 VK_AMDGPU_GOTPCREL32_LO, // symbol@gotpcrel32@lo 292 VK_AMDGPU_GOTPCREL32_HI, // symbol@gotpcrel32@hi 293 VK_AMDGPU_REL32_LO, // symbol@rel32@lo 294 VK_AMDGPU_REL32_HI, // symbol@rel32@hi 295 VK_AMDGPU_REL64, // symbol@rel64 296 297 VK_TPREL, 298 VK_DTPREL 299 }; 300 301 private: 302 /// The symbol reference modifier. 303 const VariantKind Kind; 304 305 /// Specifies how the variant kind should be printed. 306 const unsigned UseParensForSymbolVariant : 1; 307 308 // FIXME: Remove this bit. 309 const unsigned HasSubsectionsViaSymbols : 1; 310 311 /// The symbol being referenced. 312 const MCSymbol *Symbol; 313 314 explicit MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind, 315 const MCAsmInfo *MAI, SMLoc Loc = SMLoc()); 316 317 public: 318 /// \name Construction 319 /// @{ 320 create(const MCSymbol * Symbol,MCContext & Ctx)321 static const MCSymbolRefExpr *create(const MCSymbol *Symbol, MCContext &Ctx) { 322 return MCSymbolRefExpr::create(Symbol, VK_None, Ctx); 323 } 324 325 static const MCSymbolRefExpr *create(const MCSymbol *Symbol, VariantKind Kind, 326 MCContext &Ctx, SMLoc Loc = SMLoc()); 327 static const MCSymbolRefExpr *create(StringRef Name, VariantKind Kind, 328 MCContext &Ctx); 329 330 /// @} 331 /// \name Accessors 332 /// @{ 333 getSymbol()334 const MCSymbol &getSymbol() const { return *Symbol; } 335 getKind()336 VariantKind getKind() const { return Kind; } 337 338 void printVariantKind(raw_ostream &OS) const; 339 hasSubsectionsViaSymbols()340 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; } 341 342 /// @} 343 /// \name Static Utility Functions 344 /// @{ 345 346 static StringRef getVariantKindName(VariantKind Kind); 347 348 static VariantKind getVariantKindForName(StringRef Name); 349 350 /// @} 351 classof(const MCExpr * E)352 static bool classof(const MCExpr *E) { 353 return E->getKind() == MCExpr::SymbolRef; 354 } 355 }; 356 357 /// Unary assembler expressions. 358 class MCUnaryExpr : public MCExpr { 359 public: 360 enum Opcode { 361 LNot, ///< Logical negation. 362 Minus, ///< Unary minus. 363 Not, ///< Bitwise negation. 364 Plus ///< Unary plus. 365 }; 366 367 private: 368 Opcode Op; 369 const MCExpr *Expr; 370 MCUnaryExpr(Opcode Op,const MCExpr * Expr,SMLoc Loc)371 MCUnaryExpr(Opcode Op, const MCExpr *Expr, SMLoc Loc) 372 : MCExpr(MCExpr::Unary, Loc), Op(Op), Expr(Expr) {} 373 374 public: 375 /// \name Construction 376 /// @{ 377 378 static const MCUnaryExpr *create(Opcode Op, const MCExpr *Expr, 379 MCContext &Ctx, SMLoc Loc = SMLoc()); 380 381 static const MCUnaryExpr *createLNot(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) { 382 return create(LNot, Expr, Ctx, Loc); 383 } 384 385 static const MCUnaryExpr *createMinus(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) { 386 return create(Minus, Expr, Ctx, Loc); 387 } 388 389 static const MCUnaryExpr *createNot(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) { 390 return create(Not, Expr, Ctx, Loc); 391 } 392 393 static const MCUnaryExpr *createPlus(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) { 394 return create(Plus, Expr, Ctx, Loc); 395 } 396 397 /// @} 398 /// \name Accessors 399 /// @{ 400 401 /// Get the kind of this unary expression. getOpcode()402 Opcode getOpcode() const { return Op; } 403 404 /// Get the child of this unary expression. getSubExpr()405 const MCExpr *getSubExpr() const { return Expr; } 406 407 /// @} 408 classof(const MCExpr * E)409 static bool classof(const MCExpr *E) { 410 return E->getKind() == MCExpr::Unary; 411 } 412 }; 413 414 /// Binary assembler expressions. 415 class MCBinaryExpr : public MCExpr { 416 public: 417 enum Opcode { 418 Add, ///< Addition. 419 And, ///< Bitwise and. 420 Div, ///< Signed division. 421 EQ, ///< Equality comparison. 422 GT, ///< Signed greater than comparison (result is either 0 or some 423 ///< target-specific non-zero value) 424 GTE, ///< Signed greater than or equal comparison (result is either 0 or 425 ///< some target-specific non-zero value). 426 LAnd, ///< Logical and. 427 LOr, ///< Logical or. 428 LT, ///< Signed less than comparison (result is either 0 or 429 ///< some target-specific non-zero value). 430 LTE, ///< Signed less than or equal comparison (result is either 0 or 431 ///< some target-specific non-zero value). 432 Mod, ///< Signed remainder. 433 Mul, ///< Multiplication. 434 NE, ///< Inequality comparison. 435 Or, ///< Bitwise or. 436 Shl, ///< Shift left. 437 AShr, ///< Arithmetic shift right. 438 LShr, ///< Logical shift right. 439 Sub, ///< Subtraction. 440 Xor ///< Bitwise exclusive or. 441 }; 442 443 private: 444 Opcode Op; 445 const MCExpr *LHS, *RHS; 446 447 MCBinaryExpr(Opcode Op, const MCExpr *LHS, const MCExpr *RHS, 448 SMLoc Loc = SMLoc()) MCExpr(MCExpr::Binary,Loc)449 : MCExpr(MCExpr::Binary, Loc), Op(Op), LHS(LHS), RHS(RHS) {} 450 451 public: 452 /// \name Construction 453 /// @{ 454 455 static const MCBinaryExpr *create(Opcode Op, const MCExpr *LHS, 456 const MCExpr *RHS, MCContext &Ctx, 457 SMLoc Loc = SMLoc()); 458 createAdd(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)459 static const MCBinaryExpr *createAdd(const MCExpr *LHS, const MCExpr *RHS, 460 MCContext &Ctx) { 461 return create(Add, LHS, RHS, Ctx); 462 } 463 createAnd(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)464 static const MCBinaryExpr *createAnd(const MCExpr *LHS, const MCExpr *RHS, 465 MCContext &Ctx) { 466 return create(And, LHS, RHS, Ctx); 467 } 468 createDiv(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)469 static const MCBinaryExpr *createDiv(const MCExpr *LHS, const MCExpr *RHS, 470 MCContext &Ctx) { 471 return create(Div, LHS, RHS, Ctx); 472 } 473 createEQ(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)474 static const MCBinaryExpr *createEQ(const MCExpr *LHS, const MCExpr *RHS, 475 MCContext &Ctx) { 476 return create(EQ, LHS, RHS, Ctx); 477 } 478 createGT(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)479 static const MCBinaryExpr *createGT(const MCExpr *LHS, const MCExpr *RHS, 480 MCContext &Ctx) { 481 return create(GT, LHS, RHS, Ctx); 482 } 483 createGTE(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)484 static const MCBinaryExpr *createGTE(const MCExpr *LHS, const MCExpr *RHS, 485 MCContext &Ctx) { 486 return create(GTE, LHS, RHS, Ctx); 487 } 488 createLAnd(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)489 static const MCBinaryExpr *createLAnd(const MCExpr *LHS, const MCExpr *RHS, 490 MCContext &Ctx) { 491 return create(LAnd, LHS, RHS, Ctx); 492 } 493 createLOr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)494 static const MCBinaryExpr *createLOr(const MCExpr *LHS, const MCExpr *RHS, 495 MCContext &Ctx) { 496 return create(LOr, LHS, RHS, Ctx); 497 } 498 createLT(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)499 static const MCBinaryExpr *createLT(const MCExpr *LHS, const MCExpr *RHS, 500 MCContext &Ctx) { 501 return create(LT, LHS, RHS, Ctx); 502 } 503 createLTE(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)504 static const MCBinaryExpr *createLTE(const MCExpr *LHS, const MCExpr *RHS, 505 MCContext &Ctx) { 506 return create(LTE, LHS, RHS, Ctx); 507 } 508 createMod(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)509 static const MCBinaryExpr *createMod(const MCExpr *LHS, const MCExpr *RHS, 510 MCContext &Ctx) { 511 return create(Mod, LHS, RHS, Ctx); 512 } 513 createMul(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)514 static const MCBinaryExpr *createMul(const MCExpr *LHS, const MCExpr *RHS, 515 MCContext &Ctx) { 516 return create(Mul, LHS, RHS, Ctx); 517 } 518 createNE(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)519 static const MCBinaryExpr *createNE(const MCExpr *LHS, const MCExpr *RHS, 520 MCContext &Ctx) { 521 return create(NE, LHS, RHS, Ctx); 522 } 523 createOr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)524 static const MCBinaryExpr *createOr(const MCExpr *LHS, const MCExpr *RHS, 525 MCContext &Ctx) { 526 return create(Or, LHS, RHS, Ctx); 527 } 528 createShl(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)529 static const MCBinaryExpr *createShl(const MCExpr *LHS, const MCExpr *RHS, 530 MCContext &Ctx) { 531 return create(Shl, LHS, RHS, Ctx); 532 } 533 createAShr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)534 static const MCBinaryExpr *createAShr(const MCExpr *LHS, const MCExpr *RHS, 535 MCContext &Ctx) { 536 return create(AShr, LHS, RHS, Ctx); 537 } 538 createLShr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)539 static const MCBinaryExpr *createLShr(const MCExpr *LHS, const MCExpr *RHS, 540 MCContext &Ctx) { 541 return create(LShr, LHS, RHS, Ctx); 542 } 543 createSub(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)544 static const MCBinaryExpr *createSub(const MCExpr *LHS, const MCExpr *RHS, 545 MCContext &Ctx) { 546 return create(Sub, LHS, RHS, Ctx); 547 } 548 createXor(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)549 static const MCBinaryExpr *createXor(const MCExpr *LHS, const MCExpr *RHS, 550 MCContext &Ctx) { 551 return create(Xor, LHS, RHS, Ctx); 552 } 553 554 /// @} 555 /// \name Accessors 556 /// @{ 557 558 /// Get the kind of this binary expression. getOpcode()559 Opcode getOpcode() const { return Op; } 560 561 /// Get the left-hand side expression of the binary operator. getLHS()562 const MCExpr *getLHS() const { return LHS; } 563 564 /// Get the right-hand side expression of the binary operator. getRHS()565 const MCExpr *getRHS() const { return RHS; } 566 567 /// @} 568 classof(const MCExpr * E)569 static bool classof(const MCExpr *E) { 570 return E->getKind() == MCExpr::Binary; 571 } 572 }; 573 574 /// This is an extension point for target-specific MCExpr subclasses to 575 /// implement. 576 /// 577 /// NOTE: All subclasses are required to have trivial destructors because 578 /// MCExprs are bump pointer allocated and not destructed. 579 class MCTargetExpr : public MCExpr { 580 virtual void anchor(); 581 582 protected: MCTargetExpr()583 MCTargetExpr() : MCExpr(Target, SMLoc()) {} 584 virtual ~MCTargetExpr() = default; 585 586 public: 587 virtual void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const = 0; 588 virtual bool evaluateAsRelocatableImpl(MCValue &Res, 589 const MCAsmLayout *Layout, 590 const MCFixup *Fixup) const = 0; 591 // allow Target Expressions to be checked for equality isEqualTo(const MCExpr * x)592 virtual bool isEqualTo(const MCExpr *x) const { return false; } 593 // This should be set when assigned expressions are not valid ".set" 594 // expressions, e.g. registers, and must be inlined. inlineAssignedExpr()595 virtual bool inlineAssignedExpr() const { return false; } 596 virtual void visitUsedExpr(MCStreamer& Streamer) const = 0; 597 virtual MCFragment *findAssociatedFragment() const = 0; 598 599 virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0; 600 classof(const MCExpr * E)601 static bool classof(const MCExpr *E) { 602 return E->getKind() == MCExpr::Target; 603 } 604 }; 605 606 } // end namespace llvm 607 608 #endif // LLVM_MC_MCEXPR_H 609