1//===- MCExpr.cpp - Assembly Level Expression Implementation --------------===// 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#include "llvm/MC/MCExpr.h" 11#include "llvm/ADT/Statistic.h" 12#include "llvm/ADT/StringSwitch.h" 13#include "llvm/MC/MCAsmInfo.h" 14#include "llvm/MC/MCAsmLayout.h" 15#include "llvm/MC/MCAssembler.h" 16#include "llvm/MC/MCContext.h" 17#include "llvm/MC/MCObjectWriter.h" 18#include "llvm/MC/MCSymbol.h" 19#include "llvm/MC/MCValue.h" 20#include "llvm/Support/Debug.h" 21#include "llvm/Support/ErrorHandling.h" 22#include "llvm/Support/raw_ostream.h" 23using namespace llvm; 24 25#define DEBUG_TYPE "mcexpr" 26 27namespace { 28namespace stats { 29STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations"); 30} 31} 32 33void MCExpr::print(raw_ostream &OS) const { 34 switch (getKind()) { 35 case MCExpr::Target: 36 return cast<MCTargetExpr>(this)->PrintImpl(OS); 37 case MCExpr::Constant: 38 OS << cast<MCConstantExpr>(*this).getValue(); 39 return; 40 41 case MCExpr::SymbolRef: { 42 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this); 43 const MCSymbol &Sym = SRE.getSymbol(); 44 // Parenthesize names that start with $ so that they don't look like 45 // absolute names. 46 bool UseParens = Sym.getName()[0] == '$'; 47 if (UseParens) 48 OS << '(' << Sym << ')'; 49 else 50 OS << Sym; 51 52 if (SRE.getKind() != MCSymbolRefExpr::VK_None) { 53 if (SRE.getMCAsmInfo().useParensForSymbolVariant()) 54 OS << '(' << MCSymbolRefExpr::getVariantKindName(SRE.getKind()) << ')'; 55 else 56 OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind()); 57 } 58 59 return; 60 } 61 62 case MCExpr::Unary: { 63 const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this); 64 switch (UE.getOpcode()) { 65 case MCUnaryExpr::LNot: OS << '!'; break; 66 case MCUnaryExpr::Minus: OS << '-'; break; 67 case MCUnaryExpr::Not: OS << '~'; break; 68 case MCUnaryExpr::Plus: OS << '+'; break; 69 } 70 OS << *UE.getSubExpr(); 71 return; 72 } 73 74 case MCExpr::Binary: { 75 const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this); 76 77 // Only print parens around the LHS if it is non-trivial. 78 if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) { 79 OS << *BE.getLHS(); 80 } else { 81 OS << '(' << *BE.getLHS() << ')'; 82 } 83 84 switch (BE.getOpcode()) { 85 case MCBinaryExpr::Add: 86 // Print "X-42" instead of "X+-42". 87 if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) { 88 if (RHSC->getValue() < 0) { 89 OS << RHSC->getValue(); 90 return; 91 } 92 } 93 94 OS << '+'; 95 break; 96 case MCBinaryExpr::And: OS << '&'; break; 97 case MCBinaryExpr::Div: OS << '/'; break; 98 case MCBinaryExpr::EQ: OS << "=="; break; 99 case MCBinaryExpr::GT: OS << '>'; break; 100 case MCBinaryExpr::GTE: OS << ">="; break; 101 case MCBinaryExpr::LAnd: OS << "&&"; break; 102 case MCBinaryExpr::LOr: OS << "||"; break; 103 case MCBinaryExpr::LT: OS << '<'; break; 104 case MCBinaryExpr::LTE: OS << "<="; break; 105 case MCBinaryExpr::Mod: OS << '%'; break; 106 case MCBinaryExpr::Mul: OS << '*'; break; 107 case MCBinaryExpr::NE: OS << "!="; break; 108 case MCBinaryExpr::Or: OS << '|'; break; 109 case MCBinaryExpr::Shl: OS << "<<"; break; 110 case MCBinaryExpr::Shr: OS << ">>"; break; 111 case MCBinaryExpr::Sub: OS << '-'; break; 112 case MCBinaryExpr::Xor: OS << '^'; break; 113 } 114 115 // Only print parens around the LHS if it is non-trivial. 116 if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) { 117 OS << *BE.getRHS(); 118 } else { 119 OS << '(' << *BE.getRHS() << ')'; 120 } 121 return; 122 } 123 } 124 125 llvm_unreachable("Invalid expression kind!"); 126} 127 128#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 129void MCExpr::dump() const { 130 print(dbgs()); 131 dbgs() << '\n'; 132} 133#endif 134 135/* *** */ 136 137const MCBinaryExpr *MCBinaryExpr::Create(Opcode Opc, const MCExpr *LHS, 138 const MCExpr *RHS, MCContext &Ctx) { 139 return new (Ctx) MCBinaryExpr(Opc, LHS, RHS); 140} 141 142const MCUnaryExpr *MCUnaryExpr::Create(Opcode Opc, const MCExpr *Expr, 143 MCContext &Ctx) { 144 return new (Ctx) MCUnaryExpr(Opc, Expr); 145} 146 147const MCConstantExpr *MCConstantExpr::Create(int64_t Value, MCContext &Ctx) { 148 return new (Ctx) MCConstantExpr(Value); 149} 150 151/* *** */ 152 153const MCSymbolRefExpr *MCSymbolRefExpr::Create(const MCSymbol *Sym, 154 VariantKind Kind, 155 MCContext &Ctx) { 156 return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo()); 157} 158 159const MCSymbolRefExpr *MCSymbolRefExpr::Create(StringRef Name, VariantKind Kind, 160 MCContext &Ctx) { 161 return Create(Ctx.GetOrCreateSymbol(Name), Kind, Ctx); 162} 163 164StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) { 165 switch (Kind) { 166 case VK_Invalid: return "<<invalid>>"; 167 case VK_None: return "<<none>>"; 168 169 case VK_GOT: return "GOT"; 170 case VK_GOTOFF: return "GOTOFF"; 171 case VK_GOTPCREL: return "GOTPCREL"; 172 case VK_GOTTPOFF: return "GOTTPOFF"; 173 case VK_INDNTPOFF: return "INDNTPOFF"; 174 case VK_NTPOFF: return "NTPOFF"; 175 case VK_GOTNTPOFF: return "GOTNTPOFF"; 176 case VK_PLT: return "PLT"; 177 case VK_TLSGD: return "TLSGD"; 178 case VK_TLSLD: return "TLSLD"; 179 case VK_TLSLDM: return "TLSLDM"; 180 case VK_TPOFF: return "TPOFF"; 181 case VK_DTPOFF: return "DTPOFF"; 182 case VK_TLVP: return "TLVP"; 183 case VK_TLVPPAGE: return "TLVPPAGE"; 184 case VK_TLVPPAGEOFF: return "TLVPPAGEOFF"; 185 case VK_PAGE: return "PAGE"; 186 case VK_PAGEOFF: return "PAGEOFF"; 187 case VK_GOTPAGE: return "GOTPAGE"; 188 case VK_GOTPAGEOFF: return "GOTPAGEOFF"; 189 case VK_SECREL: return "SECREL32"; 190 case VK_WEAKREF: return "WEAKREF"; 191 case VK_ARM_NONE: return "none"; 192 case VK_ARM_TARGET1: return "target1"; 193 case VK_ARM_TARGET2: return "target2"; 194 case VK_ARM_PREL31: return "prel31"; 195 case VK_ARM_TLSLDO: return "tlsldo"; 196 case VK_ARM_TLSCALL: return "tlscall"; 197 case VK_ARM_TLSDESC: return "tlsdesc"; 198 case VK_ARM_TLSDESCSEQ: return "tlsdescseq"; 199 case VK_PPC_LO: return "l"; 200 case VK_PPC_HI: return "h"; 201 case VK_PPC_HA: return "ha"; 202 case VK_PPC_HIGHER: return "higher"; 203 case VK_PPC_HIGHERA: return "highera"; 204 case VK_PPC_HIGHEST: return "highest"; 205 case VK_PPC_HIGHESTA: return "highesta"; 206 case VK_PPC_GOT_LO: return "got@l"; 207 case VK_PPC_GOT_HI: return "got@h"; 208 case VK_PPC_GOT_HA: return "got@ha"; 209 case VK_PPC_TOCBASE: return "tocbase"; 210 case VK_PPC_TOC: return "toc"; 211 case VK_PPC_TOC_LO: return "toc@l"; 212 case VK_PPC_TOC_HI: return "toc@h"; 213 case VK_PPC_TOC_HA: return "toc@ha"; 214 case VK_PPC_DTPMOD: return "dtpmod"; 215 case VK_PPC_TPREL: return "tprel"; 216 case VK_PPC_TPREL_LO: return "tprel@l"; 217 case VK_PPC_TPREL_HI: return "tprel@h"; 218 case VK_PPC_TPREL_HA: return "tprel@ha"; 219 case VK_PPC_TPREL_HIGHER: return "tprel@higher"; 220 case VK_PPC_TPREL_HIGHERA: return "tprel@highera"; 221 case VK_PPC_TPREL_HIGHEST: return "tprel@highest"; 222 case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta"; 223 case VK_PPC_DTPREL: return "dtprel"; 224 case VK_PPC_DTPREL_LO: return "dtprel@l"; 225 case VK_PPC_DTPREL_HI: return "dtprel@h"; 226 case VK_PPC_DTPREL_HA: return "dtprel@ha"; 227 case VK_PPC_DTPREL_HIGHER: return "dtprel@higher"; 228 case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera"; 229 case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest"; 230 case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta"; 231 case VK_PPC_GOT_TPREL: return "got@tprel"; 232 case VK_PPC_GOT_TPREL_LO: return "got@tprel@l"; 233 case VK_PPC_GOT_TPREL_HI: return "got@tprel@h"; 234 case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha"; 235 case VK_PPC_GOT_DTPREL: return "got@dtprel"; 236 case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l"; 237 case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h"; 238 case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha"; 239 case VK_PPC_TLS: return "tls"; 240 case VK_PPC_GOT_TLSGD: return "got@tlsgd"; 241 case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l"; 242 case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h"; 243 case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha"; 244 case VK_PPC_TLSGD: return "tlsgd"; 245 case VK_PPC_GOT_TLSLD: return "got@tlsld"; 246 case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l"; 247 case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h"; 248 case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha"; 249 case VK_PPC_TLSLD: return "tlsld"; 250 case VK_Mips_GPREL: return "GPREL"; 251 case VK_Mips_GOT_CALL: return "GOT_CALL"; 252 case VK_Mips_GOT16: return "GOT16"; 253 case VK_Mips_GOT: return "GOT"; 254 case VK_Mips_ABS_HI: return "ABS_HI"; 255 case VK_Mips_ABS_LO: return "ABS_LO"; 256 case VK_Mips_TLSGD: return "TLSGD"; 257 case VK_Mips_TLSLDM: return "TLSLDM"; 258 case VK_Mips_DTPREL_HI: return "DTPREL_HI"; 259 case VK_Mips_DTPREL_LO: return "DTPREL_LO"; 260 case VK_Mips_GOTTPREL: return "GOTTPREL"; 261 case VK_Mips_TPREL_HI: return "TPREL_HI"; 262 case VK_Mips_TPREL_LO: return "TPREL_LO"; 263 case VK_Mips_GPOFF_HI: return "GPOFF_HI"; 264 case VK_Mips_GPOFF_LO: return "GPOFF_LO"; 265 case VK_Mips_GOT_DISP: return "GOT_DISP"; 266 case VK_Mips_GOT_PAGE: return "GOT_PAGE"; 267 case VK_Mips_GOT_OFST: return "GOT_OFST"; 268 case VK_Mips_HIGHER: return "HIGHER"; 269 case VK_Mips_HIGHEST: return "HIGHEST"; 270 case VK_Mips_GOT_HI16: return "GOT_HI16"; 271 case VK_Mips_GOT_LO16: return "GOT_LO16"; 272 case VK_Mips_CALL_HI16: return "CALL_HI16"; 273 case VK_Mips_CALL_LO16: return "CALL_LO16"; 274 case VK_Mips_PCREL_HI16: return "PCREL_HI16"; 275 case VK_Mips_PCREL_LO16: return "PCREL_LO16"; 276 case VK_COFF_IMGREL32: return "IMGREL32"; 277 } 278 llvm_unreachable("Invalid variant kind"); 279} 280 281MCSymbolRefExpr::VariantKind 282MCSymbolRefExpr::getVariantKindForName(StringRef Name) { 283 return StringSwitch<VariantKind>(Name) 284 .Case("GOT", VK_GOT) 285 .Case("got", VK_GOT) 286 .Case("GOTOFF", VK_GOTOFF) 287 .Case("gotoff", VK_GOTOFF) 288 .Case("GOTPCREL", VK_GOTPCREL) 289 .Case("gotpcrel", VK_GOTPCREL) 290 .Case("GOT_PREL", VK_GOTPCREL) 291 .Case("got_prel", VK_GOTPCREL) 292 .Case("GOTTPOFF", VK_GOTTPOFF) 293 .Case("gottpoff", VK_GOTTPOFF) 294 .Case("INDNTPOFF", VK_INDNTPOFF) 295 .Case("indntpoff", VK_INDNTPOFF) 296 .Case("NTPOFF", VK_NTPOFF) 297 .Case("ntpoff", VK_NTPOFF) 298 .Case("GOTNTPOFF", VK_GOTNTPOFF) 299 .Case("gotntpoff", VK_GOTNTPOFF) 300 .Case("PLT", VK_PLT) 301 .Case("plt", VK_PLT) 302 .Case("TLSGD", VK_TLSGD) 303 .Case("tlsgd", VK_TLSGD) 304 .Case("TLSLD", VK_TLSLD) 305 .Case("tlsld", VK_TLSLD) 306 .Case("TLSLDM", VK_TLSLDM) 307 .Case("tlsldm", VK_TLSLDM) 308 .Case("TPOFF", VK_TPOFF) 309 .Case("tpoff", VK_TPOFF) 310 .Case("DTPOFF", VK_DTPOFF) 311 .Case("dtpoff", VK_DTPOFF) 312 .Case("TLVP", VK_TLVP) 313 .Case("tlvp", VK_TLVP) 314 .Case("TLVPPAGE", VK_TLVPPAGE) 315 .Case("tlvppage", VK_TLVPPAGE) 316 .Case("TLVPPAGEOFF", VK_TLVPPAGEOFF) 317 .Case("tlvppageoff", VK_TLVPPAGEOFF) 318 .Case("PAGE", VK_PAGE) 319 .Case("page", VK_PAGE) 320 .Case("PAGEOFF", VK_PAGEOFF) 321 .Case("pageoff", VK_PAGEOFF) 322 .Case("GOTPAGE", VK_GOTPAGE) 323 .Case("gotpage", VK_GOTPAGE) 324 .Case("GOTPAGEOFF", VK_GOTPAGEOFF) 325 .Case("gotpageoff", VK_GOTPAGEOFF) 326 .Case("IMGREL", VK_COFF_IMGREL32) 327 .Case("imgrel", VK_COFF_IMGREL32) 328 .Case("SECREL32", VK_SECREL) 329 .Case("secrel32", VK_SECREL) 330 .Case("L", VK_PPC_LO) 331 .Case("l", VK_PPC_LO) 332 .Case("H", VK_PPC_HI) 333 .Case("h", VK_PPC_HI) 334 .Case("HA", VK_PPC_HA) 335 .Case("ha", VK_PPC_HA) 336 .Case("HIGHER", VK_PPC_HIGHER) 337 .Case("higher", VK_PPC_HIGHER) 338 .Case("HIGHERA", VK_PPC_HIGHERA) 339 .Case("highera", VK_PPC_HIGHERA) 340 .Case("HIGHEST", VK_PPC_HIGHEST) 341 .Case("highest", VK_PPC_HIGHEST) 342 .Case("HIGHESTA", VK_PPC_HIGHESTA) 343 .Case("highesta", VK_PPC_HIGHESTA) 344 .Case("GOT@L", VK_PPC_GOT_LO) 345 .Case("got@l", VK_PPC_GOT_LO) 346 .Case("GOT@H", VK_PPC_GOT_HI) 347 .Case("got@h", VK_PPC_GOT_HI) 348 .Case("GOT@HA", VK_PPC_GOT_HA) 349 .Case("got@ha", VK_PPC_GOT_HA) 350 .Case("TOCBASE", VK_PPC_TOCBASE) 351 .Case("tocbase", VK_PPC_TOCBASE) 352 .Case("TOC", VK_PPC_TOC) 353 .Case("toc", VK_PPC_TOC) 354 .Case("TOC@L", VK_PPC_TOC_LO) 355 .Case("toc@l", VK_PPC_TOC_LO) 356 .Case("TOC@H", VK_PPC_TOC_HI) 357 .Case("toc@h", VK_PPC_TOC_HI) 358 .Case("TOC@HA", VK_PPC_TOC_HA) 359 .Case("toc@ha", VK_PPC_TOC_HA) 360 .Case("TLS", VK_PPC_TLS) 361 .Case("tls", VK_PPC_TLS) 362 .Case("DTPMOD", VK_PPC_DTPMOD) 363 .Case("dtpmod", VK_PPC_DTPMOD) 364 .Case("TPREL", VK_PPC_TPREL) 365 .Case("tprel", VK_PPC_TPREL) 366 .Case("TPREL@L", VK_PPC_TPREL_LO) 367 .Case("tprel@l", VK_PPC_TPREL_LO) 368 .Case("TPREL@H", VK_PPC_TPREL_HI) 369 .Case("tprel@h", VK_PPC_TPREL_HI) 370 .Case("TPREL@HA", VK_PPC_TPREL_HA) 371 .Case("tprel@ha", VK_PPC_TPREL_HA) 372 .Case("TPREL@HIGHER", VK_PPC_TPREL_HIGHER) 373 .Case("tprel@higher", VK_PPC_TPREL_HIGHER) 374 .Case("TPREL@HIGHERA", VK_PPC_TPREL_HIGHERA) 375 .Case("tprel@highera", VK_PPC_TPREL_HIGHERA) 376 .Case("TPREL@HIGHEST", VK_PPC_TPREL_HIGHEST) 377 .Case("tprel@highest", VK_PPC_TPREL_HIGHEST) 378 .Case("TPREL@HIGHESTA", VK_PPC_TPREL_HIGHESTA) 379 .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA) 380 .Case("DTPREL", VK_PPC_DTPREL) 381 .Case("dtprel", VK_PPC_DTPREL) 382 .Case("DTPREL@L", VK_PPC_DTPREL_LO) 383 .Case("dtprel@l", VK_PPC_DTPREL_LO) 384 .Case("DTPREL@H", VK_PPC_DTPREL_HI) 385 .Case("dtprel@h", VK_PPC_DTPREL_HI) 386 .Case("DTPREL@HA", VK_PPC_DTPREL_HA) 387 .Case("dtprel@ha", VK_PPC_DTPREL_HA) 388 .Case("DTPREL@HIGHER", VK_PPC_DTPREL_HIGHER) 389 .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER) 390 .Case("DTPREL@HIGHERA", VK_PPC_DTPREL_HIGHERA) 391 .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA) 392 .Case("DTPREL@HIGHEST", VK_PPC_DTPREL_HIGHEST) 393 .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST) 394 .Case("DTPREL@HIGHESTA", VK_PPC_DTPREL_HIGHESTA) 395 .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA) 396 .Case("GOT@TPREL", VK_PPC_GOT_TPREL) 397 .Case("got@tprel", VK_PPC_GOT_TPREL) 398 .Case("GOT@TPREL@L", VK_PPC_GOT_TPREL_LO) 399 .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO) 400 .Case("GOT@TPREL@H", VK_PPC_GOT_TPREL_HI) 401 .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI) 402 .Case("GOT@TPREL@HA", VK_PPC_GOT_TPREL_HA) 403 .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA) 404 .Case("GOT@DTPREL", VK_PPC_GOT_DTPREL) 405 .Case("got@dtprel", VK_PPC_GOT_DTPREL) 406 .Case("GOT@DTPREL@L", VK_PPC_GOT_DTPREL_LO) 407 .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO) 408 .Case("GOT@DTPREL@H", VK_PPC_GOT_DTPREL_HI) 409 .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI) 410 .Case("GOT@DTPREL@HA", VK_PPC_GOT_DTPREL_HA) 411 .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA) 412 .Case("GOT@TLSGD", VK_PPC_GOT_TLSGD) 413 .Case("got@tlsgd", VK_PPC_GOT_TLSGD) 414 .Case("GOT@TLSGD@L", VK_PPC_GOT_TLSGD_LO) 415 .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO) 416 .Case("GOT@TLSGD@H", VK_PPC_GOT_TLSGD_HI) 417 .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI) 418 .Case("GOT@TLSGD@HA", VK_PPC_GOT_TLSGD_HA) 419 .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA) 420 .Case("GOT@TLSLD", VK_PPC_GOT_TLSLD) 421 .Case("got@tlsld", VK_PPC_GOT_TLSLD) 422 .Case("GOT@TLSLD@L", VK_PPC_GOT_TLSLD_LO) 423 .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO) 424 .Case("GOT@TLSLD@H", VK_PPC_GOT_TLSLD_HI) 425 .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI) 426 .Case("GOT@TLSLD@HA", VK_PPC_GOT_TLSLD_HA) 427 .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA) 428 .Case("NONE", VK_ARM_NONE) 429 .Case("none", VK_ARM_NONE) 430 .Case("TARGET1", VK_ARM_TARGET1) 431 .Case("target1", VK_ARM_TARGET1) 432 .Case("TARGET2", VK_ARM_TARGET2) 433 .Case("target2", VK_ARM_TARGET2) 434 .Case("PREL31", VK_ARM_PREL31) 435 .Case("prel31", VK_ARM_PREL31) 436 .Case("TLSLDO", VK_ARM_TLSLDO) 437 .Case("tlsldo", VK_ARM_TLSLDO) 438 .Case("TLSCALL", VK_ARM_TLSCALL) 439 .Case("tlscall", VK_ARM_TLSCALL) 440 .Case("TLSDESC", VK_ARM_TLSDESC) 441 .Case("tlsdesc", VK_ARM_TLSDESC) 442 .Default(VK_Invalid); 443} 444 445/* *** */ 446 447void MCTargetExpr::anchor() {} 448 449/* *** */ 450 451bool MCExpr::EvaluateAsAbsolute(int64_t &Res) const { 452 return EvaluateAsAbsolute(Res, nullptr, nullptr, nullptr); 453} 454 455bool MCExpr::EvaluateAsAbsolute(int64_t &Res, 456 const MCAsmLayout &Layout) const { 457 return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr); 458} 459 460bool MCExpr::EvaluateAsAbsolute(int64_t &Res, 461 const MCAsmLayout &Layout, 462 const SectionAddrMap &Addrs) const { 463 return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs); 464} 465 466bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const { 467 return EvaluateAsAbsolute(Res, &Asm, nullptr, nullptr); 468} 469 470bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm, 471 const MCAsmLayout *Layout, 472 const SectionAddrMap *Addrs) const { 473 MCValue Value; 474 475 // Fast path constants. 476 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) { 477 Res = CE->getValue(); 478 return true; 479 } 480 481 // FIXME: The use if InSet = Addrs is a hack. Setting InSet causes us 482 // absolutize differences across sections and that is what the MachO writer 483 // uses Addrs for. 484 bool IsRelocatable = 485 EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, /*InSet*/ Addrs, 486 /*ForceVarExpansion*/ false); 487 488 // Record the current value. 489 Res = Value.getConstant(); 490 491 return IsRelocatable && Value.isAbsolute(); 492} 493 494/// \brief Helper method for \see EvaluateSymbolAdd(). 495static void AttemptToFoldSymbolOffsetDifference(const MCAssembler *Asm, 496 const MCAsmLayout *Layout, 497 const SectionAddrMap *Addrs, 498 bool InSet, 499 const MCSymbolRefExpr *&A, 500 const MCSymbolRefExpr *&B, 501 int64_t &Addend) { 502 if (!A || !B) 503 return; 504 505 const MCSymbol &SA = A->getSymbol(); 506 const MCSymbol &SB = B->getSymbol(); 507 508 if (SA.isUndefined() || SB.isUndefined()) 509 return; 510 511 if (!Asm->getWriter().IsSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet)) 512 return; 513 514 const MCSymbolData &AD = Asm->getSymbolData(SA); 515 const MCSymbolData &BD = Asm->getSymbolData(SB); 516 517 if (AD.getFragment() == BD.getFragment()) { 518 Addend += (AD.getOffset() - BD.getOffset()); 519 520 // Pointers to Thumb symbols need to have their low-bit set to allow 521 // for interworking. 522 if (Asm->isThumbFunc(&SA)) 523 Addend |= 1; 524 525 // Clear the symbol expr pointers to indicate we have folded these 526 // operands. 527 A = B = nullptr; 528 return; 529 } 530 531 if (!Layout) 532 return; 533 534 const MCSectionData &SecA = *AD.getFragment()->getParent(); 535 const MCSectionData &SecB = *BD.getFragment()->getParent(); 536 537 if ((&SecA != &SecB) && !Addrs) 538 return; 539 540 // Eagerly evaluate. 541 Addend += (Layout->getSymbolOffset(&Asm->getSymbolData(A->getSymbol())) - 542 Layout->getSymbolOffset(&Asm->getSymbolData(B->getSymbol()))); 543 if (Addrs && (&SecA != &SecB)) 544 Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB)); 545 546 // Pointers to Thumb symbols need to have their low-bit set to allow 547 // for interworking. 548 if (Asm->isThumbFunc(&SA)) 549 Addend |= 1; 550 551 // Clear the symbol expr pointers to indicate we have folded these 552 // operands. 553 A = B = nullptr; 554} 555 556/// \brief Evaluate the result of an add between (conceptually) two MCValues. 557/// 558/// This routine conceptually attempts to construct an MCValue: 559/// Result = (Result_A - Result_B + Result_Cst) 560/// from two MCValue's LHS and RHS where 561/// Result = LHS + RHS 562/// and 563/// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst). 564/// 565/// This routine attempts to aggresively fold the operands such that the result 566/// is representable in an MCValue, but may not always succeed. 567/// 568/// \returns True on success, false if the result is not representable in an 569/// MCValue. 570 571/// NOTE: It is really important to have both the Asm and Layout arguments. 572/// They might look redundant, but this function can be used before layout 573/// is done (see the object streamer for example) and having the Asm argument 574/// lets us avoid relaxations early. 575static bool EvaluateSymbolicAdd(const MCAssembler *Asm, 576 const MCAsmLayout *Layout, 577 const SectionAddrMap *Addrs, 578 bool InSet, 579 const MCValue &LHS,const MCSymbolRefExpr *RHS_A, 580 const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst, 581 MCValue &Res) { 582 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy 583 // about dealing with modifiers. This will ultimately bite us, one day. 584 const MCSymbolRefExpr *LHS_A = LHS.getSymA(); 585 const MCSymbolRefExpr *LHS_B = LHS.getSymB(); 586 int64_t LHS_Cst = LHS.getConstant(); 587 588 // Fold the result constant immediately. 589 int64_t Result_Cst = LHS_Cst + RHS_Cst; 590 591 assert((!Layout || Asm) && 592 "Must have an assembler object if layout is given!"); 593 594 // If we have a layout, we can fold resolved differences. 595 if (Asm) { 596 // First, fold out any differences which are fully resolved. By 597 // reassociating terms in 598 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst). 599 // we have the four possible differences: 600 // (LHS_A - LHS_B), 601 // (LHS_A - RHS_B), 602 // (RHS_A - LHS_B), 603 // (RHS_A - RHS_B). 604 // Since we are attempting to be as aggressive as possible about folding, we 605 // attempt to evaluate each possible alternative. 606 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B, 607 Result_Cst); 608 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B, 609 Result_Cst); 610 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B, 611 Result_Cst); 612 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B, 613 Result_Cst); 614 } 615 616 // We can't represent the addition or subtraction of two symbols. 617 if ((LHS_A && RHS_A) || (LHS_B && RHS_B)) 618 return false; 619 620 // At this point, we have at most one additive symbol and one subtractive 621 // symbol -- find them. 622 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A; 623 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B; 624 625 // If we have a negated symbol, then we must have also have a non-negated 626 // symbol in order to encode the expression. 627 if (B && !A) 628 return false; 629 630 Res = MCValue::get(A, B, Result_Cst); 631 return true; 632} 633 634bool MCExpr::EvaluateAsRelocatable(MCValue &Res, 635 const MCAsmLayout *Layout) const { 636 MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr; 637 return EvaluateAsRelocatableImpl(Res, Assembler, Layout, nullptr, false, 638 /*ForceVarExpansion*/ false); 639} 640 641bool MCExpr::EvaluateAsValue(MCValue &Res, const MCAsmLayout *Layout) const { 642 MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr; 643 return EvaluateAsRelocatableImpl(Res, Assembler, Layout, nullptr, false, 644 /*ForceVarExpansion*/ true); 645} 646 647bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm, 648 const MCAsmLayout *Layout, 649 const SectionAddrMap *Addrs, bool InSet, 650 bool ForceVarExpansion) const { 651 ++stats::MCExprEvaluate; 652 653 switch (getKind()) { 654 case Target: 655 return cast<MCTargetExpr>(this)->EvaluateAsRelocatableImpl(Res, Layout); 656 657 case Constant: 658 Res = MCValue::get(cast<MCConstantExpr>(this)->getValue()); 659 return true; 660 661 case SymbolRef: { 662 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); 663 const MCSymbol &Sym = SRE->getSymbol(); 664 const MCAsmInfo &MCAsmInfo = SRE->getMCAsmInfo(); 665 666 // Evaluate recursively if this is a variable. 667 if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None) { 668 if (Sym.getVariableValue()->EvaluateAsRelocatableImpl( 669 Res, Asm, Layout, Addrs, true, ForceVarExpansion)) { 670 const MCSymbolRefExpr *A = Res.getSymA(); 671 const MCSymbolRefExpr *B = Res.getSymB(); 672 673 if (MCAsmInfo.hasSubsectionsViaSymbols()) { 674 // FIXME: This is small hack. Given 675 // a = b + 4 676 // .long a 677 // the OS X assembler will completely drop the 4. We should probably 678 // include it in the relocation or produce an error if that is not 679 // possible. 680 if (!A && !B) 681 return true; 682 } else { 683 if (ForceVarExpansion) 684 return true; 685 bool IsSymbol = A && A->getSymbol().isDefined(); 686 if (!IsSymbol) 687 return true; 688 } 689 } 690 } 691 692 Res = MCValue::get(SRE, nullptr, 0); 693 return true; 694 } 695 696 case Unary: { 697 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this); 698 MCValue Value; 699 700 if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, 701 InSet, ForceVarExpansion)) 702 return false; 703 704 switch (AUE->getOpcode()) { 705 case MCUnaryExpr::LNot: 706 if (!Value.isAbsolute()) 707 return false; 708 Res = MCValue::get(!Value.getConstant()); 709 break; 710 case MCUnaryExpr::Minus: 711 /// -(a - b + const) ==> (b - a - const) 712 if (Value.getSymA() && !Value.getSymB()) 713 return false; 714 Res = MCValue::get(Value.getSymB(), Value.getSymA(), 715 -Value.getConstant()); 716 break; 717 case MCUnaryExpr::Not: 718 if (!Value.isAbsolute()) 719 return false; 720 Res = MCValue::get(~Value.getConstant()); 721 break; 722 case MCUnaryExpr::Plus: 723 Res = Value; 724 break; 725 } 726 727 return true; 728 } 729 730 case Binary: { 731 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this); 732 MCValue LHSValue, RHSValue; 733 734 if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Asm, Layout, Addrs, 735 InSet, ForceVarExpansion) || 736 !ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Asm, Layout, Addrs, 737 InSet, ForceVarExpansion)) 738 return false; 739 740 // We only support a few operations on non-constant expressions, handle 741 // those first. 742 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) { 743 switch (ABE->getOpcode()) { 744 default: 745 return false; 746 case MCBinaryExpr::Sub: 747 // Negate RHS and add. 748 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, 749 RHSValue.getSymB(), RHSValue.getSymA(), 750 -RHSValue.getConstant(), 751 Res); 752 753 case MCBinaryExpr::Add: 754 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue, 755 RHSValue.getSymA(), RHSValue.getSymB(), 756 RHSValue.getConstant(), 757 Res); 758 } 759 } 760 761 // FIXME: We need target hooks for the evaluation. It may be limited in 762 // width, and gas defines the result of comparisons and right shifts 763 // differently from Apple as. 764 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant(); 765 int64_t Result = 0; 766 switch (ABE->getOpcode()) { 767 case MCBinaryExpr::Add: Result = LHS + RHS; break; 768 case MCBinaryExpr::And: Result = LHS & RHS; break; 769 case MCBinaryExpr::Div: Result = LHS / RHS; break; 770 case MCBinaryExpr::EQ: Result = LHS == RHS; break; 771 case MCBinaryExpr::GT: Result = LHS > RHS; break; 772 case MCBinaryExpr::GTE: Result = LHS >= RHS; break; 773 case MCBinaryExpr::LAnd: Result = LHS && RHS; break; 774 case MCBinaryExpr::LOr: Result = LHS || RHS; break; 775 case MCBinaryExpr::LT: Result = LHS < RHS; break; 776 case MCBinaryExpr::LTE: Result = LHS <= RHS; break; 777 case MCBinaryExpr::Mod: Result = LHS % RHS; break; 778 case MCBinaryExpr::Mul: Result = LHS * RHS; break; 779 case MCBinaryExpr::NE: Result = LHS != RHS; break; 780 case MCBinaryExpr::Or: Result = LHS | RHS; break; 781 case MCBinaryExpr::Shl: Result = LHS << RHS; break; 782 case MCBinaryExpr::Shr: Result = LHS >> RHS; break; 783 case MCBinaryExpr::Sub: Result = LHS - RHS; break; 784 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break; 785 } 786 787 Res = MCValue::get(Result); 788 return true; 789 } 790 } 791 792 llvm_unreachable("Invalid assembly expression kind!"); 793} 794 795const MCSection *MCExpr::FindAssociatedSection() const { 796 switch (getKind()) { 797 case Target: 798 // We never look through target specific expressions. 799 return cast<MCTargetExpr>(this)->FindAssociatedSection(); 800 801 case Constant: 802 return MCSymbol::AbsolutePseudoSection; 803 804 case SymbolRef: { 805 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); 806 const MCSymbol &Sym = SRE->getSymbol(); 807 808 if (Sym.isDefined()) 809 return &Sym.getSection(); 810 811 return nullptr; 812 } 813 814 case Unary: 815 return cast<MCUnaryExpr>(this)->getSubExpr()->FindAssociatedSection(); 816 817 case Binary: { 818 const MCBinaryExpr *BE = cast<MCBinaryExpr>(this); 819 const MCSection *LHS_S = BE->getLHS()->FindAssociatedSection(); 820 const MCSection *RHS_S = BE->getRHS()->FindAssociatedSection(); 821 822 // If either section is absolute, return the other. 823 if (LHS_S == MCSymbol::AbsolutePseudoSection) 824 return RHS_S; 825 if (RHS_S == MCSymbol::AbsolutePseudoSection) 826 return LHS_S; 827 828 // Otherwise, return the first non-null section. 829 return LHS_S ? LHS_S : RHS_S; 830 } 831 } 832 833 llvm_unreachable("Invalid assembly expression kind!"); 834} 835