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 MCAsmLayout; 19 class MCAssembler; 20 class MCContext; 21 class MCSection; 22 class MCSectionData; 23 class MCSymbol; 24 class MCValue; 25 class raw_ostream; 26 class StringRef; 27 typedef DenseMap<const MCSectionData*, uint64_t> SectionAddrMap; 28 29 /// MCExpr - Base class for the full range of assembler expressions which are 30 /// needed for parsing. 31 class MCExpr { 32 public: 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 41 private: 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; 50 protected: MCExpr(ExprKind _Kind)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; 57 public: 58 /// @name Accessors 59 /// @{ 60 getKind()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 }; 103 104 inline 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. 110 class MCConstantExpr : public MCExpr { 111 int64_t Value; 112 MCConstantExpr(int64_t _Value)113 explicit MCConstantExpr(int64_t _Value) 114 : MCExpr(MCExpr::Constant), Value(_Value) {} 115 116 public: 117 /// @name Construction 118 /// @{ 119 120 static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx); 121 122 /// @} 123 /// @name Accessors 124 /// @{ 125 getValue()126 int64_t getValue() const { return Value; } 127 128 /// @} 129 classof(const MCExpr * E)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. 141 class MCSymbolRefExpr : public MCExpr { 142 public: 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 }; 221 222 private: 223 /// The symbol being referenced. 224 const MCSymbol *Symbol; 225 226 /// The symbol reference modifier. 227 const VariantKind Kind; 228 MCSymbolRefExpr(const MCSymbol * _Symbol,VariantKind _Kind)229 explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind) 230 : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) { 231 assert(Symbol); 232 } 233 234 public: 235 /// @name Construction 236 /// @{ 237 Create(const MCSymbol * Symbol,MCContext & Ctx)238 static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) { 239 return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx); 240 } 241 242 static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind, 243 MCContext &Ctx); 244 static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind, 245 MCContext &Ctx); 246 247 /// @} 248 /// @name Accessors 249 /// @{ 250 getSymbol()251 const MCSymbol &getSymbol() const { return *Symbol; } 252 getKind()253 VariantKind getKind() const { return Kind; } 254 255 /// @} 256 /// @name Static Utility Functions 257 /// @{ 258 259 static StringRef getVariantKindName(VariantKind Kind); 260 261 static VariantKind getVariantKindForName(StringRef Name); 262 263 /// @} 264 classof(const MCExpr * E)265 static bool classof(const MCExpr *E) { 266 return E->getKind() == MCExpr::SymbolRef; 267 } 268 }; 269 270 /// MCUnaryExpr - Unary assembler expressions. 271 class MCUnaryExpr : public MCExpr { 272 public: 273 enum Opcode { 274 LNot, ///< Logical negation. 275 Minus, ///< Unary minus. 276 Not, ///< Bitwise negation. 277 Plus ///< Unary plus. 278 }; 279 280 private: 281 Opcode Op; 282 const MCExpr *Expr; 283 MCUnaryExpr(Opcode _Op,const MCExpr * _Expr)284 MCUnaryExpr(Opcode _Op, const MCExpr *_Expr) 285 : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {} 286 287 public: 288 /// @name Construction 289 /// @{ 290 291 static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr, 292 MCContext &Ctx); CreateLNot(const MCExpr * Expr,MCContext & Ctx)293 static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) { 294 return Create(LNot, Expr, Ctx); 295 } CreateMinus(const MCExpr * Expr,MCContext & Ctx)296 static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) { 297 return Create(Minus, Expr, Ctx); 298 } CreateNot(const MCExpr * Expr,MCContext & Ctx)299 static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) { 300 return Create(Not, Expr, Ctx); 301 } CreatePlus(const MCExpr * Expr,MCContext & Ctx)302 static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) { 303 return Create(Plus, Expr, Ctx); 304 } 305 306 /// @} 307 /// @name Accessors 308 /// @{ 309 310 /// getOpcode - Get the kind of this unary expression. getOpcode()311 Opcode getOpcode() const { return Op; } 312 313 /// getSubExpr - Get the child of this unary expression. getSubExpr()314 const MCExpr *getSubExpr() const { return Expr; } 315 316 /// @} 317 classof(const MCExpr * E)318 static bool classof(const MCExpr *E) { 319 return E->getKind() == MCExpr::Unary; 320 } 321 }; 322 323 /// MCBinaryExpr - Binary assembler expressions. 324 class MCBinaryExpr : public MCExpr { 325 public: 326 enum Opcode { 327 Add, ///< Addition. 328 And, ///< Bitwise and. 329 Div, ///< Signed division. 330 EQ, ///< Equality comparison. 331 GT, ///< Signed greater than comparison (result is either 0 or some 332 ///< target-specific non-zero value) 333 GTE, ///< Signed greater than or equal comparison (result is either 0 or 334 ///< some target-specific non-zero value). 335 LAnd, ///< Logical and. 336 LOr, ///< Logical or. 337 LT, ///< Signed less than comparison (result is either 0 or 338 ///< some target-specific non-zero value). 339 LTE, ///< Signed less than or equal comparison (result is either 0 or 340 ///< some target-specific non-zero value). 341 Mod, ///< Signed remainder. 342 Mul, ///< Multiplication. 343 NE, ///< Inequality comparison. 344 Or, ///< Bitwise or. 345 Shl, ///< Shift left. 346 Shr, ///< Shift right (arithmetic or logical, depending on target) 347 Sub, ///< Subtraction. 348 Xor ///< Bitwise exclusive or. 349 }; 350 351 private: 352 Opcode Op; 353 const MCExpr *LHS, *RHS; 354 MCBinaryExpr(Opcode _Op,const MCExpr * _LHS,const MCExpr * _RHS)355 MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS) 356 : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {} 357 358 public: 359 /// @name Construction 360 /// @{ 361 362 static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS, 363 const MCExpr *RHS, MCContext &Ctx); CreateAdd(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)364 static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS, 365 MCContext &Ctx) { 366 return Create(Add, LHS, RHS, Ctx); 367 } CreateAnd(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)368 static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS, 369 MCContext &Ctx) { 370 return Create(And, LHS, RHS, Ctx); 371 } CreateDiv(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)372 static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS, 373 MCContext &Ctx) { 374 return Create(Div, LHS, RHS, Ctx); 375 } CreateEQ(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)376 static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS, 377 MCContext &Ctx) { 378 return Create(EQ, LHS, RHS, Ctx); 379 } CreateGT(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)380 static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS, 381 MCContext &Ctx) { 382 return Create(GT, LHS, RHS, Ctx); 383 } CreateGTE(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)384 static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS, 385 MCContext &Ctx) { 386 return Create(GTE, LHS, RHS, Ctx); 387 } CreateLAnd(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)388 static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS, 389 MCContext &Ctx) { 390 return Create(LAnd, LHS, RHS, Ctx); 391 } CreateLOr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)392 static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS, 393 MCContext &Ctx) { 394 return Create(LOr, LHS, RHS, Ctx); 395 } CreateLT(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)396 static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS, 397 MCContext &Ctx) { 398 return Create(LT, LHS, RHS, Ctx); 399 } CreateLTE(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)400 static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS, 401 MCContext &Ctx) { 402 return Create(LTE, LHS, RHS, Ctx); 403 } CreateMod(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)404 static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS, 405 MCContext &Ctx) { 406 return Create(Mod, LHS, RHS, Ctx); 407 } CreateMul(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)408 static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS, 409 MCContext &Ctx) { 410 return Create(Mul, LHS, RHS, Ctx); 411 } CreateNE(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)412 static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS, 413 MCContext &Ctx) { 414 return Create(NE, LHS, RHS, Ctx); 415 } CreateOr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)416 static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS, 417 MCContext &Ctx) { 418 return Create(Or, LHS, RHS, Ctx); 419 } CreateShl(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)420 static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS, 421 MCContext &Ctx) { 422 return Create(Shl, LHS, RHS, Ctx); 423 } CreateShr(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)424 static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS, 425 MCContext &Ctx) { 426 return Create(Shr, LHS, RHS, Ctx); 427 } CreateSub(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)428 static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS, 429 MCContext &Ctx) { 430 return Create(Sub, LHS, RHS, Ctx); 431 } CreateXor(const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx)432 static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS, 433 MCContext &Ctx) { 434 return Create(Xor, LHS, RHS, Ctx); 435 } 436 437 /// @} 438 /// @name Accessors 439 /// @{ 440 441 /// getOpcode - Get the kind of this binary expression. getOpcode()442 Opcode getOpcode() const { return Op; } 443 444 /// getLHS - Get the left-hand side expression of the binary operator. getLHS()445 const MCExpr *getLHS() const { return LHS; } 446 447 /// getRHS - Get the right-hand side expression of the binary operator. getRHS()448 const MCExpr *getRHS() const { return RHS; } 449 450 /// @} 451 classof(const MCExpr * E)452 static bool classof(const MCExpr *E) { 453 return E->getKind() == MCExpr::Binary; 454 } 455 }; 456 457 /// MCTargetExpr - This is an extension point for target-specific MCExpr 458 /// subclasses to implement. 459 /// 460 /// NOTE: All subclasses are required to have trivial destructors because 461 /// MCExprs are bump pointer allocated and not destructed. 462 class MCTargetExpr : public MCExpr { 463 virtual void anchor(); 464 protected: MCTargetExpr()465 MCTargetExpr() : MCExpr(Target) {} ~MCTargetExpr()466 virtual ~MCTargetExpr() {} 467 public: 468 469 virtual void PrintImpl(raw_ostream &OS) const = 0; 470 virtual bool EvaluateAsRelocatableImpl(MCValue &Res, 471 const MCAsmLayout *Layout) const = 0; 472 virtual void AddValueSymbols(MCAssembler *) const = 0; 473 virtual const MCSection *FindAssociatedSection() const = 0; 474 475 virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0; 476 classof(const MCExpr * E)477 static bool classof(const MCExpr *E) { 478 return E->getKind() == MCExpr::Target; 479 } 480 }; 481 482 } // end namespace llvm 483 484 #endif 485