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/MapVector.h" 14 #include "llvm/ADT/StringRef.h" 15 #include "llvm/ADT/StringSet.h" 16 #include "llvm/BinaryFormat/ELF.h" 17 #include "llvm/Support/CachePruning.h" 18 #include "llvm/Support/CodeGen.h" 19 #include "llvm/Support/Endian.h" 20 #include <atomic> 21 #include <vector> 22 23 namespace lld { 24 namespace elf { 25 26 class InputFile; 27 class InputSectionBase; 28 29 enum ELFKind { 30 ELFNoneKind, 31 ELF32LEKind, 32 ELF32BEKind, 33 ELF64LEKind, 34 ELF64BEKind 35 }; 36 37 // For --build-id. 38 enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid }; 39 40 // For --discard-{all,locals,none}. 41 enum class DiscardPolicy { Default, All, Locals, None }; 42 43 // For --icf={none,safe,all}. 44 enum class ICFLevel { None, Safe, All }; 45 46 // For --strip-{all,debug}. 47 enum class StripPolicy { None, All, Debug }; 48 49 // For --unresolved-symbols. 50 enum class UnresolvedPolicy { ReportError, Warn, Ignore }; 51 52 // For --orphan-handling. 53 enum class OrphanHandlingPolicy { Place, Warn, Error }; 54 55 // For --sort-section and linkerscript sorting rules. 56 enum class SortSectionPolicy { Default, None, Alignment, Name, Priority }; 57 58 // For --target2 59 enum class Target2Policy { Abs, Rel, GotRel }; 60 61 // For tracking ARM Float Argument PCS 62 enum class ARMVFPArgKind { Default, Base, VFP, ToolChain }; 63 64 struct SymbolVersion { 65 llvm::StringRef name; 66 bool isExternCpp; 67 bool hasWildcard; 68 }; 69 70 // This struct contains symbols version definition that 71 // can be found in version script if it is used for link. 72 struct VersionDefinition { 73 llvm::StringRef name; 74 uint16_t id = 0; 75 std::vector<SymbolVersion> globals; 76 }; 77 78 // This struct contains the global configuration for the linker. 79 // Most fields are direct mapping from the command line options 80 // and such fields have the same name as the corresponding options. 81 // Most fields are initialized by the driver. 82 struct Configuration { 83 uint8_t osabi = 0; 84 uint32_t andFeatures = 0; 85 llvm::CachePruningPolicy thinLTOCachePolicy; 86 llvm::StringMap<uint64_t> sectionStartMap; 87 llvm::StringRef chroot; 88 llvm::StringRef dynamicLinker; 89 llvm::StringRef dwoDir; 90 llvm::StringRef entry; 91 llvm::StringRef emulation; 92 llvm::StringRef fini; 93 llvm::StringRef init; 94 llvm::StringRef ltoAAPipeline; 95 llvm::StringRef ltoCSProfileFile; 96 llvm::StringRef ltoNewPmPasses; 97 llvm::StringRef ltoObjPath; 98 llvm::StringRef ltoSampleProfile; 99 llvm::StringRef mapFile; 100 llvm::StringRef outputFile; 101 llvm::StringRef optRemarksFilename; 102 llvm::StringRef optRemarksPasses; 103 llvm::StringRef optRemarksFormat; 104 llvm::StringRef progName; 105 llvm::StringRef printSymbolOrder; 106 llvm::StringRef soName; 107 llvm::StringRef sysroot; 108 llvm::StringRef thinLTOCacheDir; 109 llvm::StringRef thinLTOIndexOnlyArg; 110 std::pair<llvm::StringRef, llvm::StringRef> thinLTOObjectSuffixReplace; 111 std::pair<llvm::StringRef, llvm::StringRef> thinLTOPrefixReplace; 112 std::string rpath; 113 std::vector<VersionDefinition> versionDefinitions; 114 std::vector<llvm::StringRef> auxiliaryList; 115 std::vector<llvm::StringRef> filterList; 116 std::vector<llvm::StringRef> searchPaths; 117 std::vector<llvm::StringRef> symbolOrderingFile; 118 std::vector<llvm::StringRef> undefined; 119 std::vector<SymbolVersion> dynamicList; 120 std::vector<SymbolVersion> versionScriptGlobals; 121 std::vector<SymbolVersion> versionScriptLocals; 122 std::vector<uint8_t> buildIdVector; 123 llvm::MapVector<std::pair<const InputSectionBase *, const InputSectionBase *>, 124 uint64_t> 125 callGraphProfile; 126 bool allowMultipleDefinition; 127 bool allowShlibUndefined; 128 bool androidPackDynRelocs; 129 bool armHasBlx = false; 130 bool armHasMovtMovw = false; 131 bool armJ1J2BranchEncoding = false; 132 bool asNeeded = false; 133 bool bsymbolic; 134 bool bsymbolicFunctions; 135 bool callGraphProfileSort; 136 bool checkSections; 137 bool compressDebugSections; 138 bool cref; 139 bool defineCommon; 140 bool demangle = true; 141 bool dependentLibraries; 142 bool disableVerify; 143 bool ehFrameHdr; 144 bool emitLLVM; 145 bool emitRelocs; 146 bool enableNewDtags; 147 bool executeOnly; 148 bool exportDynamic; 149 bool fixCortexA53Errata843419; 150 bool forceBTI; 151 bool formatBinary = false; 152 bool requireCET; 153 bool gcSections; 154 bool gdbIndex; 155 bool gnuHash = false; 156 bool gnuUnique; 157 bool hasDynamicList = false; 158 bool hasDynSymTab; 159 bool ignoreDataAddressEquality; 160 bool ignoreFunctionAddressEquality; 161 bool ltoCSProfileGenerate; 162 bool ltoDebugPassManager; 163 bool ltoNewPassManager; 164 bool mergeArmExidx; 165 bool mipsN32Abi = false; 166 bool nmagic; 167 bool noinhibitExec; 168 bool nostdlib; 169 bool oFormatBinary; 170 bool omagic; 171 bool optRemarksWithHotness; 172 bool pacPlt; 173 bool picThunk; 174 bool pie; 175 bool printGcSections; 176 bool printIcfSections; 177 bool relocatable; 178 bool relrPackDynRelocs; 179 bool saveTemps; 180 bool singleRoRx; 181 bool shared; 182 bool isStatic = false; 183 bool sysvHash = false; 184 bool target1Rel; 185 bool trace; 186 bool thinLTOEmitImportsFiles; 187 bool thinLTOIndexOnly; 188 bool tocOptimize; 189 bool undefinedVersion; 190 bool useAndroidRelrTags = false; 191 bool warnBackrefs; 192 bool warnCommon; 193 bool warnIfuncTextrel; 194 bool warnMissingEntry; 195 bool warnSymbolOrdering; 196 bool writeAddends; 197 bool zCombreloc; 198 bool zCopyreloc; 199 bool zExecstack; 200 bool zGlobal; 201 bool zHazardplt; 202 bool zIfuncNoplt; 203 bool zInitfirst; 204 bool zInterpose; 205 bool zKeepTextSectionPrefix; 206 bool zNodefaultlib; 207 bool zNodelete; 208 bool zNodlopen; 209 bool zNow; 210 bool zOrigin; 211 bool zRelro; 212 bool zRodynamic; 213 bool zText; 214 bool zRetpolineplt; 215 bool zWxneeded; 216 DiscardPolicy discard; 217 ICFLevel icf; 218 OrphanHandlingPolicy orphanHandling; 219 SortSectionPolicy sortSection; 220 StripPolicy strip; 221 UnresolvedPolicy unresolvedSymbols; 222 Target2Policy target2; 223 ARMVFPArgKind armVFPArgs = ARMVFPArgKind::Default; 224 BuildIdKind buildId = BuildIdKind::None; 225 ELFKind ekind = ELFNoneKind; 226 uint16_t defaultSymbolVersion = llvm::ELF::VER_NDX_GLOBAL; 227 uint16_t emachine = llvm::ELF::EM_NONE; 228 llvm::Optional<uint64_t> imageBase; 229 uint64_t commonPageSize; 230 uint64_t maxPageSize; 231 uint64_t mipsGotSize; 232 uint64_t zStackSize; 233 unsigned ltoPartitions; 234 unsigned ltoo; 235 unsigned optimize; 236 unsigned thinLTOJobs; 237 int32_t splitStackAdjustSize; 238 239 // The following config options do not directly correspond to any 240 // particualr command line options. 241 242 // True if we need to pass through relocations in input files to the 243 // output file. Usually false because we consume relocations. 244 bool copyRelocs; 245 246 // True if the target is ELF64. False if ELF32. 247 bool is64; 248 249 // True if the target is little-endian. False if big-endian. 250 bool isLE; 251 252 // endianness::little if isLE is true. endianness::big otherwise. 253 llvm::support::endianness endianness; 254 255 // True if the target is the little-endian MIPS64. 256 // 257 // The reason why we have this variable only for the MIPS is because 258 // we use this often. Some ELF headers for MIPS64EL are in a 259 // mixed-endian (which is horrible and I'd say that's a serious spec 260 // bug), and we need to know whether we are reading MIPS ELF files or 261 // not in various places. 262 // 263 // (Note that MIPS64EL is not a typo for MIPS64LE. This is the official 264 // name whatever that means. A fun hypothesis is that "EL" is short for 265 // little-endian written in the little-endian order, but I don't know 266 // if that's true.) 267 bool isMips64EL; 268 269 // True if we need to set the DF_STATIC_TLS flag to an output file, 270 // which works as a hint to the dynamic loader that the file contains 271 // code compiled with the static TLS model. The thread-local variable 272 // compiled with the static TLS model is faster but less flexible, and 273 // it may not be loaded using dlopen(). 274 // 275 // We set this flag to true when we see a relocation for the static TLS 276 // model. Once this becomes true, it will never become false. 277 // 278 // Since the flag is updated by multi-threaded code, we use std::atomic. 279 // (Writing to a variable is not considered thread-safe even if the 280 // variable is boolean and we always set the same value from all threads.) 281 std::atomic<bool> hasStaticTlsModel{false}; 282 283 // Holds set of ELF header flags for the target. 284 uint32_t eflags = 0; 285 286 // The ELF spec defines two types of relocation table entries, RELA and 287 // REL. RELA is a triplet of (offset, info, addend) while REL is a 288 // tuple of (offset, info). Addends for REL are implicit and read from 289 // the location where the relocations are applied. So, REL is more 290 // compact than RELA but requires a bit of more work to process. 291 // 292 // (From the linker writer's view, this distinction is not necessary. 293 // If the ELF had chosen whichever and sticked with it, it would have 294 // been easier to write code to process relocations, but it's too late 295 // to change the spec.) 296 // 297 // Each ABI defines its relocation type. IsRela is true if target 298 // uses RELA. As far as we know, all 64-bit ABIs are using RELA. A 299 // few 32-bit ABIs are using RELA too. 300 bool isRela; 301 302 // True if we are creating position-independent code. 303 bool isPic; 304 305 // 4 for ELF32, 8 for ELF64. 306 int wordsize; 307 }; 308 309 // The only instance of Configuration struct. 310 extern Configuration *config; 311 312 static inline void errorOrWarn(const Twine &msg) { 313 if (!config->noinhibitExec) 314 error(msg); 315 else 316 warn(msg); 317 } 318 } // namespace elf 319 } // namespace lld 320 321 #endif 322