1 //===- Config.h -------------------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLD_ELF_CONFIG_H 10 #define LLD_ELF_CONFIG_H 11 12 #include "lld/Common/ErrorHandler.h" 13 #include "llvm/ADT/CachedHashString.h" 14 #include "llvm/ADT/DenseSet.h" 15 #include "llvm/ADT/MapVector.h" 16 #include "llvm/ADT/SetVector.h" 17 #include "llvm/ADT/StringRef.h" 18 #include "llvm/ADT/StringSet.h" 19 #include "llvm/BinaryFormat/ELF.h" 20 #include "llvm/Support/CachePruning.h" 21 #include "llvm/Support/CodeGen.h" 22 #include "llvm/Support/Endian.h" 23 #include "llvm/Support/GlobPattern.h" 24 #include "llvm/Support/PrettyStackTrace.h" 25 #include <atomic> 26 #include <memory> 27 #include <vector> 28 29 namespace lld { 30 namespace elf { 31 32 class InputFile; 33 class BinaryFile; 34 class BitcodeFile; 35 class ELFFileBase; 36 class SharedFile; 37 class InputSectionBase; 38 class Symbol; 39 40 enum ELFKind : uint8_t { 41 ELFNoneKind, 42 ELF32LEKind, 43 ELF32BEKind, 44 ELF64LEKind, 45 ELF64BEKind 46 }; 47 48 // For -Bno-symbolic, -Bsymbolic-non-weak-functions, -Bsymbolic-functions, 49 // -Bsymbolic. 50 enum class BsymbolicKind { None, NonWeakFunctions, Functions, All }; 51 52 // For --build-id. 53 enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid }; 54 55 // For --discard-{all,locals,none}. 56 enum class DiscardPolicy { Default, All, Locals, None }; 57 58 // For --icf={none,safe,all}. 59 enum class ICFLevel { None, Safe, All }; 60 61 // For --strip-{all,debug}. 62 enum class StripPolicy { None, All, Debug }; 63 64 // For --unresolved-symbols. 65 enum class UnresolvedPolicy { ReportError, Warn, Ignore }; 66 67 // For --orphan-handling. 68 enum class OrphanHandlingPolicy { Place, Warn, Error }; 69 70 // For --sort-section and linkerscript sorting rules. 71 enum class SortSectionPolicy { Default, None, Alignment, Name, Priority }; 72 73 // For --target2 74 enum class Target2Policy { Abs, Rel, GotRel }; 75 76 // For tracking ARM Float Argument PCS 77 enum class ARMVFPArgKind { Default, Base, VFP, ToolChain }; 78 79 // For -z noseparate-code, -z separate-code and -z separate-loadable-segments. 80 enum class SeparateSegmentKind { None, Code, Loadable }; 81 82 // For -z *stack 83 enum class GnuStackKind { None, Exec, NoExec }; 84 85 struct SymbolVersion { 86 llvm::StringRef name; 87 bool isExternCpp; 88 bool hasWildcard; 89 }; 90 91 // This struct contains symbols version definition that 92 // can be found in version script if it is used for link. 93 struct VersionDefinition { 94 llvm::StringRef name; 95 uint16_t id; 96 SmallVector<SymbolVersion, 0> nonLocalPatterns; 97 SmallVector<SymbolVersion, 0> localPatterns; 98 }; 99 100 // This struct contains the global configuration for the linker. 101 // Most fields are direct mapping from the command line options 102 // and such fields have the same name as the corresponding options. 103 // Most fields are initialized by the driver. 104 struct Configuration { 105 uint8_t osabi = 0; 106 uint32_t andFeatures = 0; 107 llvm::CachePruningPolicy thinLTOCachePolicy; 108 llvm::SetVector<llvm::CachedHashString> dependencyFiles; // for --dependency-file 109 llvm::StringMap<uint64_t> sectionStartMap; 110 llvm::StringRef bfdname; 111 llvm::StringRef chroot; 112 llvm::StringRef dependencyFile; 113 llvm::StringRef dwoDir; 114 llvm::StringRef dynamicLinker; 115 llvm::StringRef entry; 116 llvm::StringRef emulation; 117 llvm::StringRef fini; 118 llvm::StringRef init; 119 llvm::StringRef ltoAAPipeline; 120 llvm::StringRef ltoCSProfileFile; 121 llvm::StringRef ltoNewPmPasses; 122 llvm::StringRef ltoObjPath; 123 llvm::StringRef ltoSampleProfile; 124 llvm::StringRef mapFile; 125 llvm::StringRef outputFile; 126 llvm::StringRef optRemarksFilename; 127 llvm::Optional<uint64_t> optRemarksHotnessThreshold = 0; 128 llvm::StringRef optRemarksPasses; 129 llvm::StringRef optRemarksFormat; 130 llvm::StringRef optStatsFilename; 131 llvm::StringRef progName; 132 llvm::StringRef printArchiveStats; 133 llvm::StringRef printSymbolOrder; 134 llvm::StringRef soName; 135 llvm::StringRef sysroot; 136 llvm::StringRef thinLTOCacheDir; 137 llvm::StringRef thinLTOIndexOnlyArg; 138 llvm::StringRef whyExtract; 139 StringRef zBtiReport = "none"; 140 StringRef zCetReport = "none"; 141 llvm::StringRef ltoBasicBlockSections; 142 std::pair<llvm::StringRef, llvm::StringRef> thinLTOObjectSuffixReplace; 143 std::pair<llvm::StringRef, llvm::StringRef> thinLTOPrefixReplace; 144 std::string rpath; 145 std::vector<VersionDefinition> versionDefinitions; 146 std::vector<llvm::StringRef> auxiliaryList; 147 std::vector<llvm::StringRef> filterList; 148 std::vector<llvm::StringRef> passPlugins; 149 std::vector<llvm::StringRef> searchPaths; 150 std::vector<llvm::StringRef> symbolOrderingFile; 151 std::vector<llvm::StringRef> thinLTOModulesToCompile; 152 std::vector<llvm::StringRef> undefined; 153 std::vector<SymbolVersion> dynamicList; 154 std::vector<uint8_t> buildIdVector; 155 llvm::MapVector<std::pair<const InputSectionBase *, const InputSectionBase *>, 156 uint64_t> 157 callGraphProfile; 158 bool allowMultipleDefinition; 159 bool androidPackDynRelocs = false; 160 bool armHasBlx = false; 161 bool armHasMovtMovw = false; 162 bool armJ1J2BranchEncoding = false; 163 bool asNeeded = false; 164 BsymbolicKind bsymbolic = BsymbolicKind::None; 165 bool callGraphProfileSort; 166 bool checkSections; 167 bool checkDynamicRelocs; 168 bool compressDebugSections; 169 bool cref; 170 std::vector<std::pair<llvm::GlobPattern, uint64_t>> deadRelocInNonAlloc; 171 bool demangle = true; 172 bool dependentLibraries; 173 bool disableVerify; 174 bool ehFrameHdr; 175 bool emitLLVM; 176 bool emitRelocs; 177 bool enableNewDtags; 178 bool executeOnly; 179 bool exportDynamic; 180 bool fixCortexA53Errata843419; 181 bool fixCortexA8; 182 bool formatBinary = false; 183 bool fortranCommon; 184 bool gcSections; 185 bool gdbIndex; 186 bool gnuHash = false; 187 bool gnuUnique; 188 bool hasDynSymTab; 189 bool ignoreDataAddressEquality; 190 bool ignoreFunctionAddressEquality; 191 bool ltoCSProfileGenerate; 192 bool ltoPGOWarnMismatch; 193 bool ltoDebugPassManager; 194 bool ltoEmitAsm; 195 bool ltoUniqueBasicBlockSectionNames; 196 bool ltoWholeProgramVisibility; 197 bool mergeArmExidx; 198 bool mipsN32Abi = false; 199 bool mmapOutputFile; 200 bool nmagic; 201 bool noDynamicLinker = false; 202 bool noinhibitExec; 203 bool nostdlib; 204 bool oFormatBinary; 205 bool omagic; 206 bool opaquePointers; 207 bool optEB = false; 208 bool optEL = false; 209 bool optimizeBBJumps; 210 bool optRemarksWithHotness; 211 bool picThunk; 212 bool pie; 213 bool printGcSections; 214 bool printIcfSections; 215 bool relax; 216 bool relocatable; 217 bool relrGlibc = false; 218 bool relrPackDynRelocs = false; 219 llvm::DenseSet<llvm::StringRef> saveTempsArgs; 220 std::vector<std::pair<llvm::GlobPattern, uint32_t>> shuffleSections; 221 bool singleRoRx; 222 bool shared; 223 bool symbolic; 224 bool isStatic = false; 225 bool sysvHash = false; 226 bool target1Rel; 227 bool trace; 228 bool thinLTOEmitImportsFiles; 229 bool thinLTOEmitIndexFiles; 230 bool thinLTOIndexOnly; 231 bool timeTraceEnabled; 232 bool tocOptimize; 233 bool pcRelOptimize; 234 bool undefinedVersion; 235 bool unique; 236 bool useAndroidRelrTags = false; 237 bool warnBackrefs; 238 std::vector<llvm::GlobPattern> warnBackrefsExclude; 239 bool warnCommon; 240 bool warnMissingEntry; 241 bool warnSymbolOrdering; 242 bool writeAddends; 243 bool zCombreloc; 244 bool zCopyreloc; 245 bool zForceBti; 246 bool zForceIbt; 247 bool zGlobal; 248 bool zHazardplt; 249 bool zIfuncNoplt; 250 bool zInitfirst; 251 bool zInterpose; 252 bool zKeepTextSectionPrefix; 253 bool zNodefaultlib; 254 bool zNodelete; 255 bool zNodlopen; 256 bool zNow; 257 bool zOrigin; 258 bool zPacPlt; 259 bool zRelro; 260 bool zRodynamic; 261 bool zShstk; 262 bool zStartStopGC; 263 uint8_t zStartStopVisibility; 264 bool zText; 265 bool zRetpolineplt; 266 bool zWxneeded; 267 DiscardPolicy discard; 268 GnuStackKind zGnustack; 269 ICFLevel icf; 270 OrphanHandlingPolicy orphanHandling; 271 SortSectionPolicy sortSection; 272 StripPolicy strip; 273 UnresolvedPolicy unresolvedSymbols; 274 UnresolvedPolicy unresolvedSymbolsInShlib; 275 Target2Policy target2; 276 bool power10Stubs; 277 ARMVFPArgKind armVFPArgs = ARMVFPArgKind::Default; 278 BuildIdKind buildId = BuildIdKind::None; 279 SeparateSegmentKind zSeparate; 280 ELFKind ekind = ELFNoneKind; 281 uint16_t emachine = llvm::ELF::EM_NONE; 282 llvm::Optional<uint64_t> imageBase; 283 uint64_t commonPageSize; 284 uint64_t maxPageSize; 285 uint64_t mipsGotSize; 286 uint64_t zStackSize; 287 unsigned ltoPartitions; 288 unsigned ltoo; 289 unsigned optimize; 290 StringRef thinLTOJobs; 291 unsigned timeTraceGranularity; 292 int32_t splitStackAdjustSize; 293 StringRef packageMetadata; 294 295 // The following config options do not directly correspond to any 296 // particular command line options. 297 298 // True if we need to pass through relocations in input files to the 299 // output file. Usually false because we consume relocations. 300 bool copyRelocs; 301 302 // True if the target is ELF64. False if ELF32. 303 bool is64; 304 305 // True if the target is little-endian. False if big-endian. 306 bool isLE; 307 308 // endianness::little if isLE is true. endianness::big otherwise. 309 llvm::support::endianness endianness; 310 311 // True if the target is the little-endian MIPS64. 312 // 313 // The reason why we have this variable only for the MIPS is because 314 // we use this often. Some ELF headers for MIPS64EL are in a 315 // mixed-endian (which is horrible and I'd say that's a serious spec 316 // bug), and we need to know whether we are reading MIPS ELF files or 317 // not in various places. 318 // 319 // (Note that MIPS64EL is not a typo for MIPS64LE. This is the official 320 // name whatever that means. A fun hypothesis is that "EL" is short for 321 // little-endian written in the little-endian order, but I don't know 322 // if that's true.) 323 bool isMips64EL; 324 325 // True if we need to reserve two .got entries for local-dynamic TLS model. 326 bool needsTlsLd = false; 327 328 // True if we need to set the DF_STATIC_TLS flag to an output file, which 329 // works as a hint to the dynamic loader that the shared object contains code 330 // compiled with the initial-exec TLS model. 331 bool hasTlsIe = false; 332 333 // Holds set of ELF header flags for the target. 334 uint32_t eflags = 0; 335 336 // The ELF spec defines two types of relocation table entries, RELA and 337 // REL. RELA is a triplet of (offset, info, addend) while REL is a 338 // tuple of (offset, info). Addends for REL are implicit and read from 339 // the location where the relocations are applied. So, REL is more 340 // compact than RELA but requires a bit of more work to process. 341 // 342 // (From the linker writer's view, this distinction is not necessary. 343 // If the ELF had chosen whichever and sticked with it, it would have 344 // been easier to write code to process relocations, but it's too late 345 // to change the spec.) 346 // 347 // Each ABI defines its relocation type. IsRela is true if target 348 // uses RELA. As far as we know, all 64-bit ABIs are using RELA. A 349 // few 32-bit ABIs are using RELA too. 350 bool isRela; 351 352 // True if we are creating position-independent code. 353 bool isPic; 354 355 // 4 for ELF32, 8 for ELF64. 356 int wordsize; 357 358 // Mode of MTE to write to the ELF note. Should be one of NT_MEMTAG_ASYNC (for 359 // async), NT_MEMTAG_SYNC (for sync), or NT_MEMTAG_LEVEL_NONE (for none). If 360 // async or sync is enabled, write the ELF note specifying the default MTE 361 // mode. 362 int androidMemtagMode; 363 // Signal to the dynamic loader to enable heap MTE. 364 bool androidMemtagHeap; 365 // Signal to the dynamic loader that this binary expects stack MTE. Generally, 366 // this means to map the primary and thread stacks as PROT_MTE. Note: This is 367 // not supported on Android 11 & 12. 368 bool androidMemtagStack; 369 }; 370 371 // The only instance of Configuration struct. 372 extern std::unique_ptr<Configuration> config; 373 374 struct DuplicateSymbol { 375 const Symbol *sym; 376 const InputFile *file; 377 InputSectionBase *section; 378 uint64_t value; 379 }; 380 381 struct Ctx { 382 SmallVector<std::unique_ptr<MemoryBuffer>> memoryBuffers; 383 SmallVector<ELFFileBase *, 0> objectFiles; 384 SmallVector<SharedFile *, 0> sharedFiles; 385 SmallVector<BinaryFile *, 0> binaryFiles; 386 SmallVector<BitcodeFile *, 0> bitcodeFiles; 387 SmallVector<BitcodeFile *, 0> lazyBitcodeFiles; 388 // Duplicate symbol candidates. 389 SmallVector<DuplicateSymbol, 0> duplicates; 390 // Symbols in a non-prevailing COMDAT group which should be changed to an 391 // Undefined. 392 SmallVector<std::pair<Symbol *, unsigned>, 0> nonPrevailingSyms; 393 // True if SHT_LLVM_SYMPART is used. 394 std::atomic<bool> hasSympart{false}; 395 // A tuple of (reference, extractedFile, sym). Used by --why-extract=. 396 SmallVector<std::tuple<std::string, const InputFile *, const Symbol &>, 0> 397 whyExtractRecords; 398 // A mapping from a symbol to an InputFile referencing it backward. Used by 399 // --warn-backrefs. 400 llvm::DenseMap<const Symbol *, 401 std::pair<const InputFile *, const InputFile *>> 402 backwardReferences; 403 }; 404 405 // The only instance of Ctx struct. 406 extern std::unique_ptr<Ctx> ctx; 407 408 // The first two elements of versionDefinitions represent VER_NDX_LOCAL and 409 // VER_NDX_GLOBAL. This helper returns other elements. 410 static inline ArrayRef<VersionDefinition> namedVersionDefs() { 411 return llvm::makeArrayRef(config->versionDefinitions).slice(2); 412 } 413 414 void errorOrWarn(const Twine &msg); 415 416 static inline void internalLinkerError(StringRef loc, const Twine &msg) { 417 errorOrWarn(loc + "internal linker error: " + msg + "\n" + 418 llvm::getBugReportMsg()); 419 } 420 421 } // namespace elf 422 } // namespace lld 423 424 #endif 425