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/MapVector.h" 15 #include "llvm/ADT/SetVector.h" 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/ADT/StringSet.h" 18 #include "llvm/BinaryFormat/ELF.h" 19 #include "llvm/Support/CachePruning.h" 20 #include "llvm/Support/CodeGen.h" 21 #include "llvm/Support/Endian.h" 22 #include "llvm/Support/GlobPattern.h" 23 #include "llvm/Support/PrettyStackTrace.h" 24 #include <atomic> 25 #include <vector> 26 27 namespace lld { 28 namespace elf { 29 30 class InputFile; 31 class InputSectionBase; 32 33 enum ELFKind { 34 ELFNoneKind, 35 ELF32LEKind, 36 ELF32BEKind, 37 ELF64LEKind, 38 ELF64BEKind 39 }; 40 41 // For -Bno-symbolic, -Bsymbolic-non-weak-functions, -Bsymbolic-functions, 42 // -Bsymbolic. 43 enum class BsymbolicKind { None, NonWeakFunctions, Functions, All }; 44 45 // For --build-id. 46 enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid }; 47 48 // For --discard-{all,locals,none}. 49 enum class DiscardPolicy { Default, All, Locals, None }; 50 51 // For --icf={none,safe,all}. 52 enum class ICFLevel { None, Safe, All }; 53 54 // For --strip-{all,debug}. 55 enum class StripPolicy { None, All, Debug }; 56 57 // For --unresolved-symbols. 58 enum class UnresolvedPolicy { ReportError, Warn, Ignore }; 59 60 // For --orphan-handling. 61 enum class OrphanHandlingPolicy { Place, Warn, Error }; 62 63 // For --sort-section and linkerscript sorting rules. 64 enum class SortSectionPolicy { Default, None, Alignment, Name, Priority }; 65 66 // For --target2 67 enum class Target2Policy { Abs, Rel, GotRel }; 68 69 // For tracking ARM Float Argument PCS 70 enum class ARMVFPArgKind { Default, Base, VFP, ToolChain }; 71 72 // For -z noseparate-code, -z separate-code and -z separate-loadable-segments. 73 enum class SeparateSegmentKind { None, Code, Loadable }; 74 75 // For -z *stack 76 enum class GnuStackKind { None, Exec, NoExec }; 77 78 struct SymbolVersion { 79 llvm::StringRef name; 80 bool isExternCpp; 81 bool hasWildcard; 82 }; 83 84 // This struct contains symbols version definition that 85 // can be found in version script if it is used for link. 86 struct VersionDefinition { 87 llvm::StringRef name; 88 uint16_t id; 89 std::vector<SymbolVersion> nonLocalPatterns; 90 std::vector<SymbolVersion> localPatterns; 91 }; 92 93 // This struct contains the global configuration for the linker. 94 // Most fields are direct mapping from the command line options 95 // and such fields have the same name as the corresponding options. 96 // Most fields are initialized by the driver. 97 struct Configuration { 98 uint8_t osabi = 0; 99 uint32_t andFeatures = 0; 100 llvm::CachePruningPolicy thinLTOCachePolicy; 101 llvm::SetVector<llvm::CachedHashString> dependencyFiles; // for --dependency-file 102 llvm::StringMap<uint64_t> sectionStartMap; 103 llvm::StringRef bfdname; 104 llvm::StringRef chroot; 105 llvm::StringRef dependencyFile; 106 llvm::StringRef dwoDir; 107 llvm::StringRef dynamicLinker; 108 llvm::StringRef entry; 109 llvm::StringRef emulation; 110 llvm::StringRef fini; 111 llvm::StringRef init; 112 llvm::StringRef ltoAAPipeline; 113 llvm::StringRef ltoCSProfileFile; 114 llvm::StringRef ltoNewPmPasses; 115 llvm::StringRef ltoObjPath; 116 llvm::StringRef ltoSampleProfile; 117 llvm::StringRef mapFile; 118 llvm::StringRef outputFile; 119 llvm::StringRef optRemarksFilename; 120 llvm::Optional<uint64_t> optRemarksHotnessThreshold = 0; 121 llvm::StringRef optRemarksPasses; 122 llvm::StringRef optRemarksFormat; 123 llvm::StringRef progName; 124 llvm::StringRef printArchiveStats; 125 llvm::StringRef printSymbolOrder; 126 llvm::StringRef soName; 127 llvm::StringRef sysroot; 128 llvm::StringRef thinLTOCacheDir; 129 llvm::StringRef thinLTOIndexOnlyArg; 130 llvm::StringRef ltoBasicBlockSections; 131 std::pair<llvm::StringRef, llvm::StringRef> thinLTOObjectSuffixReplace; 132 std::pair<llvm::StringRef, llvm::StringRef> thinLTOPrefixReplace; 133 std::string rpath; 134 std::vector<VersionDefinition> versionDefinitions; 135 std::vector<llvm::StringRef> auxiliaryList; 136 std::vector<llvm::StringRef> filterList; 137 std::vector<llvm::StringRef> searchPaths; 138 std::vector<llvm::StringRef> symbolOrderingFile; 139 std::vector<llvm::StringRef> thinLTOModulesToCompile; 140 std::vector<llvm::StringRef> undefined; 141 std::vector<SymbolVersion> dynamicList; 142 std::vector<uint8_t> buildIdVector; 143 llvm::MapVector<std::pair<const InputSectionBase *, const InputSectionBase *>, 144 uint64_t> 145 callGraphProfile; 146 bool allowMultipleDefinition; 147 bool androidPackDynRelocs; 148 bool armHasBlx = false; 149 bool armHasMovtMovw = false; 150 bool armJ1J2BranchEncoding = false; 151 bool asNeeded = false; 152 BsymbolicKind bsymbolic = BsymbolicKind::None; 153 bool callGraphProfileSort; 154 bool checkSections; 155 bool checkDynamicRelocs; 156 bool compressDebugSections; 157 bool cref; 158 std::vector<std::pair<llvm::GlobPattern, uint64_t>> deadRelocInNonAlloc; 159 bool defineCommon; 160 bool demangle = true; 161 bool dependentLibraries; 162 bool disableVerify; 163 bool ehFrameHdr; 164 bool emitLLVM; 165 bool emitRelocs; 166 bool enableNewDtags; 167 bool executeOnly; 168 bool exportDynamic; 169 bool fixCortexA53Errata843419; 170 bool fixCortexA8; 171 bool formatBinary = false; 172 bool fortranCommon; 173 bool gcSections; 174 bool gdbIndex; 175 bool gnuHash = false; 176 bool gnuUnique; 177 bool hasDynSymTab; 178 bool ignoreDataAddressEquality; 179 bool ignoreFunctionAddressEquality; 180 bool ltoCSProfileGenerate; 181 bool ltoDebugPassManager; 182 bool ltoEmitAsm; 183 bool ltoNewPassManager; 184 bool ltoPseudoProbeForProfiling; 185 bool ltoUniqueBasicBlockSectionNames; 186 bool ltoWholeProgramVisibility; 187 bool mergeArmExidx; 188 bool mipsN32Abi = false; 189 bool mmapOutputFile; 190 bool nmagic; 191 bool noDynamicLinker = false; 192 bool noinhibitExec; 193 bool nostdlib; 194 bool oFormatBinary; 195 bool omagic; 196 bool optEB = false; 197 bool optEL = false; 198 bool optimizeBBJumps; 199 bool optRemarksWithHotness; 200 bool picThunk; 201 bool pie; 202 bool printGcSections; 203 bool printIcfSections; 204 bool relocatable; 205 bool relrPackDynRelocs; 206 bool saveTemps; 207 std::vector<std::pair<llvm::GlobPattern, uint32_t>> shuffleSections; 208 bool singleRoRx; 209 bool shared; 210 bool symbolic; 211 bool isStatic = false; 212 bool sysvHash = false; 213 bool target1Rel; 214 bool trace; 215 bool thinLTOEmitImportsFiles; 216 bool thinLTOIndexOnly; 217 bool timeTraceEnabled; 218 bool tocOptimize; 219 bool pcRelOptimize; 220 bool undefinedVersion; 221 bool unique; 222 bool useAndroidRelrTags = false; 223 bool warnBackrefs; 224 std::vector<llvm::GlobPattern> warnBackrefsExclude; 225 bool warnCommon; 226 bool warnMissingEntry; 227 bool warnSymbolOrdering; 228 bool writeAddends; 229 bool zCombreloc; 230 bool zCopyreloc; 231 bool zForceBti; 232 bool zForceIbt; 233 bool zGlobal; 234 bool zHazardplt; 235 bool zIfuncNoplt; 236 bool zInitfirst; 237 bool zInterpose; 238 bool zKeepTextSectionPrefix; 239 bool zNodefaultlib; 240 bool zNodelete; 241 bool zNodlopen; 242 bool zNow; 243 bool zOrigin; 244 bool zPacPlt; 245 bool zRelro; 246 bool zRodynamic; 247 bool zShstk; 248 bool zStartStopGC; 249 uint8_t zStartStopVisibility; 250 bool zText; 251 bool zRetpolineplt; 252 bool zWxneeded; 253 DiscardPolicy discard; 254 GnuStackKind zGnustack; 255 ICFLevel icf; 256 OrphanHandlingPolicy orphanHandling; 257 SortSectionPolicy sortSection; 258 StripPolicy strip; 259 UnresolvedPolicy unresolvedSymbols; 260 UnresolvedPolicy unresolvedSymbolsInShlib; 261 Target2Policy target2; 262 bool Power10Stub; 263 ARMVFPArgKind armVFPArgs = ARMVFPArgKind::Default; 264 BuildIdKind buildId = BuildIdKind::None; 265 SeparateSegmentKind zSeparate; 266 ELFKind ekind = ELFNoneKind; 267 uint16_t emachine = llvm::ELF::EM_NONE; 268 llvm::Optional<uint64_t> imageBase; 269 uint64_t commonPageSize; 270 uint64_t maxPageSize; 271 uint64_t mipsGotSize; 272 uint64_t zStackSize; 273 unsigned ltoPartitions; 274 unsigned ltoo; 275 unsigned optimize; 276 StringRef thinLTOJobs; 277 unsigned timeTraceGranularity; 278 int32_t splitStackAdjustSize; 279 280 // The following config options do not directly correspond to any 281 // particular command line options. 282 283 // True if we need to pass through relocations in input files to the 284 // output file. Usually false because we consume relocations. 285 bool copyRelocs; 286 287 // True if the target is ELF64. False if ELF32. 288 bool is64; 289 290 // True if the target is little-endian. False if big-endian. 291 bool isLE; 292 293 // endianness::little if isLE is true. endianness::big otherwise. 294 llvm::support::endianness endianness; 295 296 // True if the target is the little-endian MIPS64. 297 // 298 // The reason why we have this variable only for the MIPS is because 299 // we use this often. Some ELF headers for MIPS64EL are in a 300 // mixed-endian (which is horrible and I'd say that's a serious spec 301 // bug), and we need to know whether we are reading MIPS ELF files or 302 // not in various places. 303 // 304 // (Note that MIPS64EL is not a typo for MIPS64LE. This is the official 305 // name whatever that means. A fun hypothesis is that "EL" is short for 306 // little-endian written in the little-endian order, but I don't know 307 // if that's true.) 308 bool isMips64EL; 309 310 // True if we need to set the DF_STATIC_TLS flag to an output file, 311 // which works as a hint to the dynamic loader that the file contains 312 // code compiled with the static TLS model. The thread-local variable 313 // compiled with the static TLS model is faster but less flexible, and 314 // it may not be loaded using dlopen(). 315 // 316 // We set this flag to true when we see a relocation for the static TLS 317 // model. Once this becomes true, it will never become false. 318 // 319 // Since the flag is updated by multi-threaded code, we use std::atomic. 320 // (Writing to a variable is not considered thread-safe even if the 321 // variable is boolean and we always set the same value from all threads.) 322 std::atomic<bool> hasStaticTlsModel{false}; 323 324 // Holds set of ELF header flags for the target. 325 uint32_t eflags = 0; 326 327 // The ELF spec defines two types of relocation table entries, RELA and 328 // REL. RELA is a triplet of (offset, info, addend) while REL is a 329 // tuple of (offset, info). Addends for REL are implicit and read from 330 // the location where the relocations are applied. So, REL is more 331 // compact than RELA but requires a bit of more work to process. 332 // 333 // (From the linker writer's view, this distinction is not necessary. 334 // If the ELF had chosen whichever and sticked with it, it would have 335 // been easier to write code to process relocations, but it's too late 336 // to change the spec.) 337 // 338 // Each ABI defines its relocation type. IsRela is true if target 339 // uses RELA. As far as we know, all 64-bit ABIs are using RELA. A 340 // few 32-bit ABIs are using RELA too. 341 bool isRela; 342 343 // True if we are creating position-independent code. 344 bool isPic; 345 346 // 4 for ELF32, 8 for ELF64. 347 int wordsize; 348 }; 349 350 // The only instance of Configuration struct. 351 extern Configuration *config; 352 353 // The first two elements of versionDefinitions represent VER_NDX_LOCAL and 354 // VER_NDX_GLOBAL. This helper returns other elements. 355 static inline ArrayRef<VersionDefinition> namedVersionDefs() { 356 return llvm::makeArrayRef(config->versionDefinitions).slice(2); 357 } 358 359 static inline void errorOrWarn(const Twine &msg) { 360 if (!config->noinhibitExec) 361 error(msg); 362 else 363 warn(msg); 364 } 365 366 static inline void internalLinkerError(StringRef loc, const Twine &msg) { 367 errorOrWarn(loc + "internal linker error: " + msg + "\n" + 368 llvm::getBugReportMsg()); 369 } 370 371 } // namespace elf 372 } // namespace lld 373 374 #endif 375