1 //===-- MipsELFObjectWriter.cpp - Mips ELF Writer -------------------------===// 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 "MCTargetDesc/MipsFixupKinds.h" 11 #include "MCTargetDesc/MipsMCTargetDesc.h" 12 #include "llvm/ADT/STLExtras.h" 13 #include "llvm/BinaryFormat/ELF.h" 14 #include "llvm/MC/MCELFObjectWriter.h" 15 #include "llvm/MC/MCFixup.h" 16 #include "llvm/MC/MCObjectWriter.h" 17 #include "llvm/MC/MCSymbolELF.h" 18 #include "llvm/Support/Casting.h" 19 #include "llvm/Support/Compiler.h" 20 #include "llvm/Support/Debug.h" 21 #include "llvm/Support/ErrorHandling.h" 22 #include "llvm/Support/MathExtras.h" 23 #include "llvm/Support/raw_ostream.h" 24 #include <algorithm> 25 #include <cassert> 26 #include <cstdint> 27 #include <iterator> 28 #include <list> 29 #include <utility> 30 31 #define DEBUG_TYPE "mips-elf-object-writer" 32 33 using namespace llvm; 34 35 namespace { 36 37 /// Holds additional information needed by the relocation ordering algorithm. 38 struct MipsRelocationEntry { 39 const ELFRelocationEntry R; ///< The relocation. 40 bool Matched = false; ///< Is this relocation part of a match. 41 42 MipsRelocationEntry(const ELFRelocationEntry &R) : R(R) {} 43 44 void print(raw_ostream &Out) const { 45 R.print(Out); 46 Out << ", Matched=" << Matched; 47 } 48 }; 49 50 #ifndef NDEBUG 51 raw_ostream &operator<<(raw_ostream &OS, const MipsRelocationEntry &RHS) { 52 RHS.print(OS); 53 return OS; 54 } 55 #endif 56 57 class MipsELFObjectWriter : public MCELFObjectTargetWriter { 58 public: 59 MipsELFObjectWriter(uint8_t OSABI, bool HasRelocationAddend, bool Is64, 60 bool IsLittleEndian); 61 62 ~MipsELFObjectWriter() override = default; 63 64 unsigned getRelocType(MCContext &Ctx, const MCValue &Target, 65 const MCFixup &Fixup, bool IsPCRel) const override; 66 bool needsRelocateWithSymbol(const MCSymbol &Sym, 67 unsigned Type) const override; 68 void sortRelocs(const MCAssembler &Asm, 69 std::vector<ELFRelocationEntry> &Relocs) override; 70 }; 71 72 /// The possible results of the Predicate function used by find_best. 73 enum FindBestPredicateResult { 74 FindBest_NoMatch = 0, ///< The current element is not a match. 75 FindBest_Match, ///< The current element is a match but better ones are 76 /// possible. 77 FindBest_PerfectMatch, ///< The current element is an unbeatable match. 78 }; 79 80 } // end anonymous namespace 81 82 /// Copy elements in the range [First, Last) to d1 when the predicate is true or 83 /// d2 when the predicate is false. This is essentially both std::copy_if and 84 /// std::remove_copy_if combined into a single pass. 85 template <class InputIt, class OutputIt1, class OutputIt2, class UnaryPredicate> 86 static std::pair<OutputIt1, OutputIt2> copy_if_else(InputIt First, InputIt Last, 87 OutputIt1 d1, OutputIt2 d2, 88 UnaryPredicate Predicate) { 89 for (InputIt I = First; I != Last; ++I) { 90 if (Predicate(*I)) { 91 *d1 = *I; 92 d1++; 93 } else { 94 *d2 = *I; 95 d2++; 96 } 97 } 98 99 return std::make_pair(d1, d2); 100 } 101 102 /// Find the best match in the range [First, Last). 103 /// 104 /// An element matches when Predicate(X) returns FindBest_Match or 105 /// FindBest_PerfectMatch. A value of FindBest_PerfectMatch also terminates 106 /// the search. BetterThan(A, B) is a comparator that returns true when A is a 107 /// better match than B. The return value is the position of the best match. 108 /// 109 /// This is similar to std::find_if but finds the best of multiple possible 110 /// matches. 111 template <class InputIt, class UnaryPredicate, class Comparator> 112 static InputIt find_best(InputIt First, InputIt Last, UnaryPredicate Predicate, 113 Comparator BetterThan) { 114 InputIt Best = Last; 115 116 for (InputIt I = First; I != Last; ++I) { 117 unsigned Matched = Predicate(*I); 118 if (Matched != FindBest_NoMatch) { 119 LLVM_DEBUG(dbgs() << std::distance(First, I) << " is a match ("; 120 I->print(dbgs()); dbgs() << ")\n"); 121 if (Best == Last || BetterThan(*I, *Best)) { 122 LLVM_DEBUG(dbgs() << ".. and it beats the last one\n"); 123 Best = I; 124 } 125 } 126 if (Matched == FindBest_PerfectMatch) { 127 LLVM_DEBUG(dbgs() << ".. and it is unbeatable\n"); 128 break; 129 } 130 } 131 132 return Best; 133 } 134 135 /// Determine the low relocation that matches the given relocation. 136 /// If the relocation does not need a low relocation then the return value 137 /// is ELF::R_MIPS_NONE. 138 /// 139 /// The relocations that need a matching low part are 140 /// R_(MIPS|MICROMIPS|MIPS16)_HI16 for all symbols and 141 /// R_(MIPS|MICROMIPS|MIPS16)_GOT16 for local symbols only. 142 static unsigned getMatchingLoType(const ELFRelocationEntry &Reloc) { 143 unsigned Type = Reloc.Type; 144 if (Type == ELF::R_MIPS_HI16) 145 return ELF::R_MIPS_LO16; 146 if (Type == ELF::R_MICROMIPS_HI16) 147 return ELF::R_MICROMIPS_LO16; 148 if (Type == ELF::R_MIPS16_HI16) 149 return ELF::R_MIPS16_LO16; 150 151 if (Reloc.OriginalSymbol->getBinding() != ELF::STB_LOCAL) 152 return ELF::R_MIPS_NONE; 153 154 if (Type == ELF::R_MIPS_GOT16) 155 return ELF::R_MIPS_LO16; 156 if (Type == ELF::R_MICROMIPS_GOT16) 157 return ELF::R_MICROMIPS_LO16; 158 if (Type == ELF::R_MIPS16_GOT16) 159 return ELF::R_MIPS16_LO16; 160 161 return ELF::R_MIPS_NONE; 162 } 163 164 /// Determine whether a relocation (X) matches the one given in R. 165 /// 166 /// A relocation matches if: 167 /// - It's type matches that of a corresponding low part. This is provided in 168 /// MatchingType for efficiency. 169 /// - It's based on the same symbol. 170 /// - It's offset of greater or equal to that of the one given in R. 171 /// It should be noted that this rule assumes the programmer does not use 172 /// offsets that exceed the alignment of the symbol. The carry-bit will be 173 /// incorrect if this is not true. 174 /// 175 /// A matching relocation is unbeatable if: 176 /// - It is not already involved in a match. 177 /// - It's offset is exactly that of the one given in R. 178 static FindBestPredicateResult isMatchingReloc(const MipsRelocationEntry &X, 179 const ELFRelocationEntry &R, 180 unsigned MatchingType) { 181 if (X.R.Type == MatchingType && X.R.OriginalSymbol == R.OriginalSymbol) { 182 if (!X.Matched && 183 X.R.OriginalAddend == R.OriginalAddend) 184 return FindBest_PerfectMatch; 185 else if (X.R.OriginalAddend >= R.OriginalAddend) 186 return FindBest_Match; 187 } 188 return FindBest_NoMatch; 189 } 190 191 /// Determine whether Candidate or PreviousBest is the better match. 192 /// The return value is true if Candidate is the better match. 193 /// 194 /// A matching relocation is a better match if: 195 /// - It has a smaller addend. 196 /// - It is not already involved in a match. 197 static bool compareMatchingRelocs(const MipsRelocationEntry &Candidate, 198 const MipsRelocationEntry &PreviousBest) { 199 if (Candidate.R.OriginalAddend != PreviousBest.R.OriginalAddend) 200 return Candidate.R.OriginalAddend < PreviousBest.R.OriginalAddend; 201 return PreviousBest.Matched && !Candidate.Matched; 202 } 203 204 #ifndef NDEBUG 205 /// Print all the relocations. 206 template <class Container> 207 static void dumpRelocs(const char *Prefix, const Container &Relocs) { 208 for (const auto &R : Relocs) 209 dbgs() << Prefix << R << "\n"; 210 } 211 #endif 212 213 MipsELFObjectWriter::MipsELFObjectWriter(uint8_t OSABI, 214 bool HasRelocationAddend, bool Is64, 215 bool IsLittleEndian) 216 : MCELFObjectTargetWriter(Is64, OSABI, ELF::EM_MIPS, HasRelocationAddend) {} 217 218 unsigned MipsELFObjectWriter::getRelocType(MCContext &Ctx, 219 const MCValue &Target, 220 const MCFixup &Fixup, 221 bool IsPCRel) const { 222 // Determine the type of the relocation. 223 unsigned Kind = (unsigned)Fixup.getKind(); 224 225 switch (Kind) { 226 case Mips::fixup_Mips_NONE: 227 return ELF::R_MIPS_NONE; 228 case FK_Data_1: 229 report_fatal_error("MIPS does not support one byte relocations"); 230 case Mips::fixup_Mips_16: 231 case FK_Data_2: 232 return IsPCRel ? ELF::R_MIPS_PC16 : ELF::R_MIPS_16; 233 case Mips::fixup_Mips_32: 234 case FK_Data_4: 235 return IsPCRel ? ELF::R_MIPS_PC32 : ELF::R_MIPS_32; 236 } 237 238 if (IsPCRel) { 239 switch (Kind) { 240 case Mips::fixup_Mips_Branch_PCRel: 241 case Mips::fixup_Mips_PC16: 242 return ELF::R_MIPS_PC16; 243 case Mips::fixup_MICROMIPS_PC7_S1: 244 return ELF::R_MICROMIPS_PC7_S1; 245 case Mips::fixup_MICROMIPS_PC10_S1: 246 return ELF::R_MICROMIPS_PC10_S1; 247 case Mips::fixup_MICROMIPS_PC16_S1: 248 return ELF::R_MICROMIPS_PC16_S1; 249 case Mips::fixup_MICROMIPS_PC26_S1: 250 return ELF::R_MICROMIPS_PC26_S1; 251 case Mips::fixup_MICROMIPS_PC19_S2: 252 return ELF::R_MICROMIPS_PC19_S2; 253 case Mips::fixup_MICROMIPS_PC18_S3: 254 return ELF::R_MICROMIPS_PC18_S3; 255 case Mips::fixup_MICROMIPS_PC21_S1: 256 return ELF::R_MICROMIPS_PC21_S1; 257 case Mips::fixup_MIPS_PC19_S2: 258 return ELF::R_MIPS_PC19_S2; 259 case Mips::fixup_MIPS_PC18_S3: 260 return ELF::R_MIPS_PC18_S3; 261 case Mips::fixup_MIPS_PC21_S2: 262 return ELF::R_MIPS_PC21_S2; 263 case Mips::fixup_MIPS_PC26_S2: 264 return ELF::R_MIPS_PC26_S2; 265 case Mips::fixup_MIPS_PCHI16: 266 return ELF::R_MIPS_PCHI16; 267 case Mips::fixup_MIPS_PCLO16: 268 return ELF::R_MIPS_PCLO16; 269 } 270 271 llvm_unreachable("invalid PC-relative fixup kind!"); 272 } 273 274 switch (Kind) { 275 case Mips::fixup_Mips_64: 276 case FK_Data_8: 277 return ELF::R_MIPS_64; 278 case FK_DTPRel_4: 279 return ELF::R_MIPS_TLS_DTPREL32; 280 case FK_DTPRel_8: 281 return ELF::R_MIPS_TLS_DTPREL64; 282 case FK_TPRel_4: 283 return ELF::R_MIPS_TLS_TPREL32; 284 case FK_TPRel_8: 285 return ELF::R_MIPS_TLS_TPREL64; 286 case FK_GPRel_4: 287 if (is64Bit()) { 288 unsigned Type = (unsigned)ELF::R_MIPS_NONE; 289 Type = setRType((unsigned)ELF::R_MIPS_GPREL32, Type); 290 Type = setRType2((unsigned)ELF::R_MIPS_64, Type); 291 Type = setRType3((unsigned)ELF::R_MIPS_NONE, Type); 292 return Type; 293 } 294 return ELF::R_MIPS_GPREL32; 295 case Mips::fixup_Mips_GPREL16: 296 return ELF::R_MIPS_GPREL16; 297 case Mips::fixup_Mips_26: 298 return ELF::R_MIPS_26; 299 case Mips::fixup_Mips_CALL16: 300 return ELF::R_MIPS_CALL16; 301 case Mips::fixup_Mips_GOT: 302 return ELF::R_MIPS_GOT16; 303 case Mips::fixup_Mips_HI16: 304 return ELF::R_MIPS_HI16; 305 case Mips::fixup_Mips_LO16: 306 return ELF::R_MIPS_LO16; 307 case Mips::fixup_Mips_TLSGD: 308 return ELF::R_MIPS_TLS_GD; 309 case Mips::fixup_Mips_GOTTPREL: 310 return ELF::R_MIPS_TLS_GOTTPREL; 311 case Mips::fixup_Mips_TPREL_HI: 312 return ELF::R_MIPS_TLS_TPREL_HI16; 313 case Mips::fixup_Mips_TPREL_LO: 314 return ELF::R_MIPS_TLS_TPREL_LO16; 315 case Mips::fixup_Mips_TLSLDM: 316 return ELF::R_MIPS_TLS_LDM; 317 case Mips::fixup_Mips_DTPREL_HI: 318 return ELF::R_MIPS_TLS_DTPREL_HI16; 319 case Mips::fixup_Mips_DTPREL_LO: 320 return ELF::R_MIPS_TLS_DTPREL_LO16; 321 case Mips::fixup_Mips_GOT_PAGE: 322 return ELF::R_MIPS_GOT_PAGE; 323 case Mips::fixup_Mips_GOT_OFST: 324 return ELF::R_MIPS_GOT_OFST; 325 case Mips::fixup_Mips_GOT_DISP: 326 return ELF::R_MIPS_GOT_DISP; 327 case Mips::fixup_Mips_GPOFF_HI: { 328 unsigned Type = (unsigned)ELF::R_MIPS_NONE; 329 Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type); 330 Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type); 331 Type = setRType3((unsigned)ELF::R_MIPS_HI16, Type); 332 return Type; 333 } 334 case Mips::fixup_Mips_GPOFF_LO: { 335 unsigned Type = (unsigned)ELF::R_MIPS_NONE; 336 Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type); 337 Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type); 338 Type = setRType3((unsigned)ELF::R_MIPS_LO16, Type); 339 return Type; 340 } 341 case Mips::fixup_Mips_HIGHER: 342 return ELF::R_MIPS_HIGHER; 343 case Mips::fixup_Mips_HIGHEST: 344 return ELF::R_MIPS_HIGHEST; 345 case Mips::fixup_Mips_SUB: 346 return ELF::R_MIPS_SUB; 347 case Mips::fixup_Mips_GOT_HI16: 348 return ELF::R_MIPS_GOT_HI16; 349 case Mips::fixup_Mips_GOT_LO16: 350 return ELF::R_MIPS_GOT_LO16; 351 case Mips::fixup_Mips_CALL_HI16: 352 return ELF::R_MIPS_CALL_HI16; 353 case Mips::fixup_Mips_CALL_LO16: 354 return ELF::R_MIPS_CALL_LO16; 355 case Mips::fixup_MICROMIPS_26_S1: 356 return ELF::R_MICROMIPS_26_S1; 357 case Mips::fixup_MICROMIPS_HI16: 358 return ELF::R_MICROMIPS_HI16; 359 case Mips::fixup_MICROMIPS_LO16: 360 return ELF::R_MICROMIPS_LO16; 361 case Mips::fixup_MICROMIPS_GOT16: 362 return ELF::R_MICROMIPS_GOT16; 363 case Mips::fixup_MICROMIPS_CALL16: 364 return ELF::R_MICROMIPS_CALL16; 365 case Mips::fixup_MICROMIPS_GOT_DISP: 366 return ELF::R_MICROMIPS_GOT_DISP; 367 case Mips::fixup_MICROMIPS_GOT_PAGE: 368 return ELF::R_MICROMIPS_GOT_PAGE; 369 case Mips::fixup_MICROMIPS_GOT_OFST: 370 return ELF::R_MICROMIPS_GOT_OFST; 371 case Mips::fixup_MICROMIPS_TLS_GD: 372 return ELF::R_MICROMIPS_TLS_GD; 373 case Mips::fixup_MICROMIPS_TLS_LDM: 374 return ELF::R_MICROMIPS_TLS_LDM; 375 case Mips::fixup_MICROMIPS_TLS_DTPREL_HI16: 376 return ELF::R_MICROMIPS_TLS_DTPREL_HI16; 377 case Mips::fixup_MICROMIPS_TLS_DTPREL_LO16: 378 return ELF::R_MICROMIPS_TLS_DTPREL_LO16; 379 case Mips::fixup_MICROMIPS_GOTTPREL: 380 return ELF::R_MICROMIPS_TLS_GOTTPREL; 381 case Mips::fixup_MICROMIPS_TLS_TPREL_HI16: 382 return ELF::R_MICROMIPS_TLS_TPREL_HI16; 383 case Mips::fixup_MICROMIPS_TLS_TPREL_LO16: 384 return ELF::R_MICROMIPS_TLS_TPREL_LO16; 385 case Mips::fixup_MICROMIPS_SUB: 386 return ELF::R_MICROMIPS_SUB; 387 } 388 389 llvm_unreachable("invalid fixup kind!"); 390 } 391 392 /// Sort relocation table entries by offset except where another order is 393 /// required by the MIPS ABI. 394 /// 395 /// MIPS has a few relocations that have an AHL component in the expression used 396 /// to evaluate them. This AHL component is an addend with the same number of 397 /// bits as a symbol value but not all of our ABI's are able to supply a 398 /// sufficiently sized addend in a single relocation. 399 /// 400 /// The O32 ABI for example, uses REL relocations which store the addend in the 401 /// section data. All the relocations with AHL components affect 16-bit fields 402 /// so the addend for a single relocation is limited to 16-bit. This ABI 403 /// resolves the limitation by linking relocations (e.g. R_MIPS_HI16 and 404 /// R_MIPS_LO16) and distributing the addend between the linked relocations. The 405 /// ABI mandates that such relocations must be next to each other in a 406 /// particular order (e.g. R_MIPS_HI16 must be immediately followed by a 407 /// matching R_MIPS_LO16) but the rule is less strict in practice. 408 /// 409 /// The de facto standard is lenient in the following ways: 410 /// - 'Immediately following' does not refer to the next relocation entry but 411 /// the next matching relocation. 412 /// - There may be multiple high parts relocations for one low part relocation. 413 /// - There may be multiple low part relocations for one high part relocation. 414 /// - The AHL addend in each part does not have to be exactly equal as long as 415 /// the difference does not affect the carry bit from bit 15 into 16. This is 416 /// to allow, for example, the use of %lo(foo) and %lo(foo+4) when loading 417 /// both halves of a long long. 418 /// 419 /// See getMatchingLoType() for a description of which high part relocations 420 /// match which low part relocations. One particular thing to note is that 421 /// R_MIPS_GOT16 and similar only have AHL addends if they refer to local 422 /// symbols. 423 /// 424 /// It should also be noted that this function is not affected by whether 425 /// the symbol was kept or rewritten into a section-relative equivalent. We 426 /// always match using the expressions from the source. 427 void MipsELFObjectWriter::sortRelocs(const MCAssembler &Asm, 428 std::vector<ELFRelocationEntry> &Relocs) { 429 // We do not need to sort the relocation table for RELA relocations which 430 // N32/N64 uses as the relocation addend contains the value we require, 431 // rather than it being split across a pair of relocations. 432 if (hasRelocationAddend()) 433 return; 434 435 if (Relocs.size() < 2) 436 return; 437 438 // Sort relocations by the address they are applied to. 439 llvm::sort(Relocs.begin(), Relocs.end(), 440 [](const ELFRelocationEntry &A, const ELFRelocationEntry &B) { 441 return A.Offset < B.Offset; 442 }); 443 444 std::list<MipsRelocationEntry> Sorted; 445 std::list<ELFRelocationEntry> Remainder; 446 447 LLVM_DEBUG(dumpRelocs("R: ", Relocs)); 448 449 // Separate the movable relocations (AHL relocations using the high bits) from 450 // the immobile relocations (everything else). This does not preserve high/low 451 // matches that already existed in the input. 452 copy_if_else(Relocs.begin(), Relocs.end(), std::back_inserter(Remainder), 453 std::back_inserter(Sorted), [](const ELFRelocationEntry &Reloc) { 454 return getMatchingLoType(Reloc) != ELF::R_MIPS_NONE; 455 }); 456 457 for (auto &R : Remainder) { 458 LLVM_DEBUG(dbgs() << "Matching: " << R << "\n"); 459 460 unsigned MatchingType = getMatchingLoType(R); 461 assert(MatchingType != ELF::R_MIPS_NONE && 462 "Wrong list for reloc that doesn't need a match"); 463 464 // Find the best matching relocation for the current high part. 465 // See isMatchingReloc for a description of a matching relocation and 466 // compareMatchingRelocs for a description of what 'best' means. 467 auto InsertionPoint = 468 find_best(Sorted.begin(), Sorted.end(), 469 [&R, &MatchingType](const MipsRelocationEntry &X) { 470 return isMatchingReloc(X, R, MatchingType); 471 }, 472 compareMatchingRelocs); 473 474 // If we matched then insert the high part in front of the match and mark 475 // both relocations as being involved in a match. We only mark the high 476 // part for cosmetic reasons in the debug output. 477 // 478 // If we failed to find a match then the high part is orphaned. This is not 479 // permitted since the relocation cannot be evaluated without knowing the 480 // carry-in. We can sometimes handle this using a matching low part that is 481 // already used in a match but we already cover that case in 482 // isMatchingReloc and compareMatchingRelocs. For the remaining cases we 483 // should insert the high part at the end of the list. This will cause the 484 // linker to fail but the alternative is to cause the linker to bind the 485 // high part to a semi-matching low part and silently calculate the wrong 486 // value. Unfortunately we have no means to warn the user that we did this 487 // so leave it up to the linker to complain about it. 488 if (InsertionPoint != Sorted.end()) 489 InsertionPoint->Matched = true; 490 Sorted.insert(InsertionPoint, R)->Matched = true; 491 } 492 493 LLVM_DEBUG(dumpRelocs("S: ", Sorted)); 494 495 assert(Relocs.size() == Sorted.size() && "Some relocs were not consumed"); 496 497 // Overwrite the original vector with the sorted elements. The caller expects 498 // them in reverse order. 499 unsigned CopyTo = 0; 500 for (const auto &R : reverse(Sorted)) 501 Relocs[CopyTo++] = R.R; 502 } 503 504 bool MipsELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym, 505 unsigned Type) const { 506 // If it's a compound relocation for N64 then we need the relocation if any 507 // sub-relocation needs it. 508 if (!isUInt<8>(Type)) 509 return needsRelocateWithSymbol(Sym, Type & 0xff) || 510 needsRelocateWithSymbol(Sym, (Type >> 8) & 0xff) || 511 needsRelocateWithSymbol(Sym, (Type >> 16) & 0xff); 512 513 switch (Type) { 514 default: 515 errs() << Type << "\n"; 516 llvm_unreachable("Unexpected relocation"); 517 return true; 518 519 // This relocation doesn't affect the section data. 520 case ELF::R_MIPS_NONE: 521 return false; 522 523 // On REL ABI's (e.g. O32), these relocations form pairs. The pairing is done 524 // by the static linker by matching the symbol and offset. 525 // We only see one relocation at a time but it's still safe to relocate with 526 // the section so long as both relocations make the same decision. 527 // 528 // Some older linkers may require the symbol for particular cases. Such cases 529 // are not supported yet but can be added as required. 530 case ELF::R_MIPS_GOT16: 531 case ELF::R_MIPS16_GOT16: 532 case ELF::R_MICROMIPS_GOT16: 533 case ELF::R_MIPS_HIGHER: 534 case ELF::R_MIPS_HIGHEST: 535 case ELF::R_MIPS_HI16: 536 case ELF::R_MIPS16_HI16: 537 case ELF::R_MICROMIPS_HI16: 538 case ELF::R_MIPS_LO16: 539 case ELF::R_MIPS16_LO16: 540 case ELF::R_MICROMIPS_LO16: 541 // FIXME: It should be safe to return false for the STO_MIPS_MICROMIPS but 542 // we neglect to handle the adjustment to the LSB of the addend that 543 // it causes in applyFixup() and similar. 544 if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS) 545 return true; 546 return false; 547 548 case ELF::R_MIPS_GOT_PAGE: 549 case ELF::R_MICROMIPS_GOT_PAGE: 550 case ELF::R_MIPS_GOT_OFST: 551 case ELF::R_MICROMIPS_GOT_OFST: 552 case ELF::R_MIPS_16: 553 case ELF::R_MIPS_32: 554 case ELF::R_MIPS_GPREL32: 555 if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS) 556 return true; 557 LLVM_FALLTHROUGH; 558 case ELF::R_MIPS_26: 559 case ELF::R_MIPS_64: 560 case ELF::R_MIPS_GPREL16: 561 case ELF::R_MIPS_PC16: 562 case ELF::R_MIPS_SUB: 563 return false; 564 565 // FIXME: Many of these relocations should probably return false but this 566 // hasn't been confirmed to be safe yet. 567 case ELF::R_MIPS_REL32: 568 case ELF::R_MIPS_LITERAL: 569 case ELF::R_MIPS_CALL16: 570 case ELF::R_MIPS_SHIFT5: 571 case ELF::R_MIPS_SHIFT6: 572 case ELF::R_MIPS_GOT_DISP: 573 case ELF::R_MIPS_GOT_HI16: 574 case ELF::R_MIPS_GOT_LO16: 575 case ELF::R_MIPS_INSERT_A: 576 case ELF::R_MIPS_INSERT_B: 577 case ELF::R_MIPS_DELETE: 578 case ELF::R_MIPS_CALL_HI16: 579 case ELF::R_MIPS_CALL_LO16: 580 case ELF::R_MIPS_SCN_DISP: 581 case ELF::R_MIPS_REL16: 582 case ELF::R_MIPS_ADD_IMMEDIATE: 583 case ELF::R_MIPS_PJUMP: 584 case ELF::R_MIPS_RELGOT: 585 case ELF::R_MIPS_JALR: 586 case ELF::R_MIPS_TLS_DTPMOD32: 587 case ELF::R_MIPS_TLS_DTPREL32: 588 case ELF::R_MIPS_TLS_DTPMOD64: 589 case ELF::R_MIPS_TLS_DTPREL64: 590 case ELF::R_MIPS_TLS_GD: 591 case ELF::R_MIPS_TLS_LDM: 592 case ELF::R_MIPS_TLS_DTPREL_HI16: 593 case ELF::R_MIPS_TLS_DTPREL_LO16: 594 case ELF::R_MIPS_TLS_GOTTPREL: 595 case ELF::R_MIPS_TLS_TPREL32: 596 case ELF::R_MIPS_TLS_TPREL64: 597 case ELF::R_MIPS_TLS_TPREL_HI16: 598 case ELF::R_MIPS_TLS_TPREL_LO16: 599 case ELF::R_MIPS_GLOB_DAT: 600 case ELF::R_MIPS_PC21_S2: 601 case ELF::R_MIPS_PC26_S2: 602 case ELF::R_MIPS_PC18_S3: 603 case ELF::R_MIPS_PC19_S2: 604 case ELF::R_MIPS_PCHI16: 605 case ELF::R_MIPS_PCLO16: 606 case ELF::R_MIPS_COPY: 607 case ELF::R_MIPS_JUMP_SLOT: 608 case ELF::R_MIPS_NUM: 609 case ELF::R_MIPS_PC32: 610 case ELF::R_MIPS_EH: 611 case ELF::R_MICROMIPS_26_S1: 612 case ELF::R_MICROMIPS_GPREL16: 613 case ELF::R_MICROMIPS_LITERAL: 614 case ELF::R_MICROMIPS_PC7_S1: 615 case ELF::R_MICROMIPS_PC10_S1: 616 case ELF::R_MICROMIPS_PC16_S1: 617 case ELF::R_MICROMIPS_CALL16: 618 case ELF::R_MICROMIPS_GOT_DISP: 619 case ELF::R_MICROMIPS_GOT_HI16: 620 case ELF::R_MICROMIPS_GOT_LO16: 621 case ELF::R_MICROMIPS_SUB: 622 case ELF::R_MICROMIPS_HIGHER: 623 case ELF::R_MICROMIPS_HIGHEST: 624 case ELF::R_MICROMIPS_CALL_HI16: 625 case ELF::R_MICROMIPS_CALL_LO16: 626 case ELF::R_MICROMIPS_SCN_DISP: 627 case ELF::R_MICROMIPS_JALR: 628 case ELF::R_MICROMIPS_HI0_LO16: 629 case ELF::R_MICROMIPS_TLS_GD: 630 case ELF::R_MICROMIPS_TLS_LDM: 631 case ELF::R_MICROMIPS_TLS_DTPREL_HI16: 632 case ELF::R_MICROMIPS_TLS_DTPREL_LO16: 633 case ELF::R_MICROMIPS_TLS_GOTTPREL: 634 case ELF::R_MICROMIPS_TLS_TPREL_HI16: 635 case ELF::R_MICROMIPS_TLS_TPREL_LO16: 636 case ELF::R_MICROMIPS_GPREL7_S2: 637 case ELF::R_MICROMIPS_PC23_S2: 638 case ELF::R_MICROMIPS_PC21_S1: 639 case ELF::R_MICROMIPS_PC26_S1: 640 case ELF::R_MICROMIPS_PC18_S3: 641 case ELF::R_MICROMIPS_PC19_S2: 642 return true; 643 644 // FIXME: Many of these should probably return false but MIPS16 isn't 645 // supported by the integrated assembler. 646 case ELF::R_MIPS16_26: 647 case ELF::R_MIPS16_GPREL: 648 case ELF::R_MIPS16_CALL16: 649 case ELF::R_MIPS16_TLS_GD: 650 case ELF::R_MIPS16_TLS_LDM: 651 case ELF::R_MIPS16_TLS_DTPREL_HI16: 652 case ELF::R_MIPS16_TLS_DTPREL_LO16: 653 case ELF::R_MIPS16_TLS_GOTTPREL: 654 case ELF::R_MIPS16_TLS_TPREL_HI16: 655 case ELF::R_MIPS16_TLS_TPREL_LO16: 656 llvm_unreachable("Unsupported MIPS16 relocation"); 657 return true; 658 } 659 } 660 661 std::unique_ptr<MCObjectWriter> 662 llvm::createMipsELFObjectWriter(raw_pwrite_stream &OS, const Triple &TT, 663 bool IsN32) { 664 uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS()); 665 bool IsN64 = TT.isArch64Bit() && !IsN32; 666 bool HasRelocationAddend = TT.isArch64Bit(); 667 auto MOTW = llvm::make_unique<MipsELFObjectWriter>( 668 OSABI, HasRelocationAddend, IsN64, TT.isLittleEndian()); 669 return createELFObjectWriter(std::move(MOTW), OS, TT.isLittleEndian()); 670 } 671