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 17 namespace llvm { 18 class MCAsmInfo; 19 class MCAsmLayout; 20 class MCAssembler; 21 class MCContext; 22 class MCFixup; 23 class MCFragment; 24 class MCSection; 25 class MCStreamer; 26 class MCSymbol; 27 class MCValue; 28 class raw_ostream; 29 class StringRef; 30 typedef DenseMap<const MCSection *, uint64_t> SectionAddrMap; 31 32 /// \brief Base class for the full range of assembler expressions which are 33 /// needed for parsing. 34 class MCExpr { 35 public: 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 44 private: 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 58 protected: 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 66 public: 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 }; 123 124 inline 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. 130 class MCConstantExpr : public MCExpr { 131 int64_t Value; 132 133 explicit MCConstantExpr(int64_t Value) 134 : MCExpr(MCExpr::Constant), Value(Value) {} 135 136 public: 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. 160 class MCSymbolRefExpr : public MCExpr { 161 public: 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 }; 296 297 private: 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); 312 313 public: 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. 354 class MCUnaryExpr : public MCExpr { 355 public: 356 enum Opcode { 357 LNot, ///< Logical negation. 358 Minus, ///< Unary minus. 359 Not, ///< Bitwise negation. 360 Plus ///< Unary plus. 361 }; 362 363 private: 364 Opcode Op; 365 const MCExpr *Expr; 366 367 MCUnaryExpr(Opcode Op, const MCExpr *Expr) 368 : MCExpr(MCExpr::Unary), Op(Op), Expr(Expr) {} 369 370 public: 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. 407 class MCBinaryExpr : public MCExpr { 408 public: 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 }; 434 435 private: 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) {} 441 442 public: 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. 550 class MCTargetExpr : public MCExpr { 551 virtual void anchor(); 552 protected: 553 MCTargetExpr() : MCExpr(Target) {} 554 virtual ~MCTargetExpr() {} 555 public: 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
