1 //===-- MCObjectFileInfo.cpp - Object File Information --------------------===// 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/MCObjectFileInfo.h" 11 #include "llvm/ADT/StringExtras.h" 12 #include "llvm/ADT/Triple.h" 13 #include "llvm/MC/MCAsmInfo.h" 14 #include "llvm/MC/MCContext.h" 15 #include "llvm/MC/MCSection.h" 16 #include "llvm/MC/MCSectionCOFF.h" 17 #include "llvm/MC/MCSectionELF.h" 18 #include "llvm/MC/MCSectionMachO.h" 19 #include "llvm/MC/MCSectionWasm.h" 20 #include "llvm/Support/COFF.h" 21 #include "llvm/Support/ELF.h" 22 23 using namespace llvm; 24 25 static bool useCompactUnwind(const Triple &T) { 26 // Only on darwin. 27 if (!T.isOSDarwin()) 28 return false; 29 30 // aarch64 always has it. 31 if (T.getArch() == Triple::aarch64) 32 return true; 33 34 // armv7k always has it. 35 if (T.isWatchABI()) 36 return true; 37 38 // Use it on newer version of OS X. 39 if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) 40 return true; 41 42 // And the iOS simulator. 43 if (T.isiOS() && 44 (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)) 45 return true; 46 47 return false; 48 } 49 50 void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) { 51 // MachO 52 SupportsWeakOmittedEHFrame = false; 53 54 EHFrameSection = Ctx->getMachOSection( 55 "__TEXT", "__eh_frame", 56 MachO::S_COALESCED | MachO::S_ATTR_NO_TOC | 57 MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT, 58 SectionKind::getReadOnly()); 59 60 if (T.isOSDarwin() && T.getArch() == Triple::aarch64) 61 SupportsCompactUnwindWithoutEHFrame = true; 62 63 if (T.isWatchABI()) 64 OmitDwarfIfHaveCompactUnwind = true; 65 66 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel 67 | dwarf::DW_EH_PE_sdata4; 68 LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel; 69 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 70 dwarf::DW_EH_PE_sdata4; 71 72 // .comm doesn't support alignment before Leopard. 73 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5)) 74 CommDirectiveSupportsAlignment = false; 75 76 TextSection // .text 77 = Ctx->getMachOSection("__TEXT", "__text", 78 MachO::S_ATTR_PURE_INSTRUCTIONS, 79 SectionKind::getText()); 80 DataSection // .data 81 = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData()); 82 83 // BSSSection might not be expected initialized on msvc. 84 BSSSection = nullptr; 85 86 TLSDataSection // .tdata 87 = Ctx->getMachOSection("__DATA", "__thread_data", 88 MachO::S_THREAD_LOCAL_REGULAR, 89 SectionKind::getData()); 90 TLSBSSSection // .tbss 91 = Ctx->getMachOSection("__DATA", "__thread_bss", 92 MachO::S_THREAD_LOCAL_ZEROFILL, 93 SectionKind::getThreadBSS()); 94 95 // TODO: Verify datarel below. 96 TLSTLVSection // .tlv 97 = Ctx->getMachOSection("__DATA", "__thread_vars", 98 MachO::S_THREAD_LOCAL_VARIABLES, 99 SectionKind::getData()); 100 101 TLSThreadInitSection = Ctx->getMachOSection( 102 "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 103 SectionKind::getData()); 104 105 CStringSection // .cstring 106 = Ctx->getMachOSection("__TEXT", "__cstring", 107 MachO::S_CSTRING_LITERALS, 108 SectionKind::getMergeable1ByteCString()); 109 UStringSection 110 = Ctx->getMachOSection("__TEXT","__ustring", 0, 111 SectionKind::getMergeable2ByteCString()); 112 FourByteConstantSection // .literal4 113 = Ctx->getMachOSection("__TEXT", "__literal4", 114 MachO::S_4BYTE_LITERALS, 115 SectionKind::getMergeableConst4()); 116 EightByteConstantSection // .literal8 117 = Ctx->getMachOSection("__TEXT", "__literal8", 118 MachO::S_8BYTE_LITERALS, 119 SectionKind::getMergeableConst8()); 120 121 SixteenByteConstantSection // .literal16 122 = Ctx->getMachOSection("__TEXT", "__literal16", 123 MachO::S_16BYTE_LITERALS, 124 SectionKind::getMergeableConst16()); 125 126 ReadOnlySection // .const 127 = Ctx->getMachOSection("__TEXT", "__const", 0, 128 SectionKind::getReadOnly()); 129 130 // If the target is not powerpc, map the coal sections to the non-coal 131 // sections. 132 // 133 // "__TEXT/__textcoal_nt" => section "__TEXT/__text" 134 // "__TEXT/__const_coal" => section "__TEXT/__const" 135 // "__DATA/__datacoal_nt" => section "__DATA/__data" 136 Triple::ArchType ArchTy = T.getArch(); 137 138 if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) { 139 TextCoalSection 140 = Ctx->getMachOSection("__TEXT", "__textcoal_nt", 141 MachO::S_COALESCED | 142 MachO::S_ATTR_PURE_INSTRUCTIONS, 143 SectionKind::getText()); 144 ConstTextCoalSection 145 = Ctx->getMachOSection("__TEXT", "__const_coal", 146 MachO::S_COALESCED, 147 SectionKind::getReadOnly()); 148 DataCoalSection = Ctx->getMachOSection( 149 "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData()); 150 } else { 151 TextCoalSection = TextSection; 152 ConstTextCoalSection = ReadOnlySection; 153 DataCoalSection = DataSection; 154 } 155 156 ConstDataSection // .const_data 157 = Ctx->getMachOSection("__DATA", "__const", 0, 158 SectionKind::getReadOnlyWithRel()); 159 DataCommonSection 160 = Ctx->getMachOSection("__DATA","__common", 161 MachO::S_ZEROFILL, 162 SectionKind::getBSS()); 163 DataBSSSection 164 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL, 165 SectionKind::getBSS()); 166 167 168 LazySymbolPointerSection 169 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr", 170 MachO::S_LAZY_SYMBOL_POINTERS, 171 SectionKind::getMetadata()); 172 NonLazySymbolPointerSection 173 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr", 174 MachO::S_NON_LAZY_SYMBOL_POINTERS, 175 SectionKind::getMetadata()); 176 177 ThreadLocalPointerSection 178 = Ctx->getMachOSection("__DATA", "__thread_ptr", 179 MachO::S_THREAD_LOCAL_VARIABLE_POINTERS, 180 SectionKind::getMetadata()); 181 182 // Exception Handling. 183 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 184 SectionKind::getReadOnlyWithRel()); 185 186 COFFDebugSymbolsSection = nullptr; 187 COFFDebugTypesSection = nullptr; 188 189 if (useCompactUnwind(T)) { 190 CompactUnwindSection = 191 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 192 SectionKind::getReadOnly()); 193 194 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 195 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 196 else if (T.getArch() == Triple::aarch64) 197 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 198 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 199 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 200 } 201 202 // Debug Information. 203 DwarfAccelNamesSection = 204 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 205 SectionKind::getMetadata(), "names_begin"); 206 DwarfAccelObjCSection = 207 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 208 SectionKind::getMetadata(), "objc_begin"); 209 // 16 character section limit... 210 DwarfAccelNamespaceSection = 211 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 212 SectionKind::getMetadata(), "namespac_begin"); 213 DwarfAccelTypesSection = 214 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 215 SectionKind::getMetadata(), "types_begin"); 216 217 DwarfAbbrevSection = 218 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 219 SectionKind::getMetadata(), "section_abbrev"); 220 DwarfInfoSection = 221 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 222 SectionKind::getMetadata(), "section_info"); 223 DwarfLineSection = 224 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 225 SectionKind::getMetadata(), "section_line"); 226 DwarfFrameSection = 227 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 228 SectionKind::getMetadata()); 229 DwarfPubNamesSection = 230 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 231 SectionKind::getMetadata()); 232 DwarfPubTypesSection = 233 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 234 SectionKind::getMetadata()); 235 DwarfGnuPubNamesSection = 236 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 237 SectionKind::getMetadata()); 238 DwarfGnuPubTypesSection = 239 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 240 SectionKind::getMetadata()); 241 DwarfStrSection = 242 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 243 SectionKind::getMetadata(), "info_string"); 244 DwarfLocSection = 245 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 246 SectionKind::getMetadata(), "section_debug_loc"); 247 DwarfARangesSection = 248 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 249 SectionKind::getMetadata()); 250 DwarfRangesSection = 251 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 252 SectionKind::getMetadata(), "debug_range"); 253 DwarfMacinfoSection = 254 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 255 SectionKind::getMetadata(), "debug_macinfo"); 256 DwarfDebugInlineSection = 257 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 258 SectionKind::getMetadata()); 259 DwarfCUIndexSection = 260 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 261 SectionKind::getMetadata()); 262 DwarfTUIndexSection = 263 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 264 SectionKind::getMetadata()); 265 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 266 0, SectionKind::getMetadata()); 267 268 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 269 0, SectionKind::getMetadata()); 270 271 TLSExtraDataSection = TLSTLVSection; 272 } 273 274 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T) { 275 switch (T.getArch()) { 276 case Triple::mips: 277 case Triple::mipsel: 278 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 279 break; 280 case Triple::mips64: 281 case Triple::mips64el: 282 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 283 break; 284 case Triple::x86_64: 285 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 286 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 287 : dwarf::DW_EH_PE_sdata4); 288 break; 289 default: 290 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 291 break; 292 } 293 294 switch (T.getArch()) { 295 case Triple::arm: 296 case Triple::armeb: 297 case Triple::thumb: 298 case Triple::thumbeb: 299 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 300 break; 301 // Fallthrough if not using EHABI 302 LLVM_FALLTHROUGH; 303 case Triple::ppc: 304 case Triple::x86: 305 PersonalityEncoding = PositionIndependent 306 ? dwarf::DW_EH_PE_indirect | 307 dwarf::DW_EH_PE_pcrel | 308 dwarf::DW_EH_PE_sdata4 309 : dwarf::DW_EH_PE_absptr; 310 LSDAEncoding = PositionIndependent 311 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 312 : dwarf::DW_EH_PE_absptr; 313 TTypeEncoding = PositionIndependent 314 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 315 dwarf::DW_EH_PE_sdata4 316 : dwarf::DW_EH_PE_absptr; 317 break; 318 case Triple::x86_64: 319 if (PositionIndependent) { 320 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 321 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 322 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 323 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 324 (CMModel == CodeModel::Small 325 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 326 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 327 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 328 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 329 } else { 330 PersonalityEncoding = 331 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 332 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 333 LSDAEncoding = (CMModel == CodeModel::Small) 334 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 335 TTypeEncoding = (CMModel == CodeModel::Small) 336 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 337 } 338 break; 339 case Triple::hexagon: 340 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 341 LSDAEncoding = dwarf::DW_EH_PE_absptr; 342 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 343 TTypeEncoding = dwarf::DW_EH_PE_absptr; 344 if (PositionIndependent) { 345 PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 346 LSDAEncoding |= dwarf::DW_EH_PE_pcrel; 347 FDECFIEncoding |= dwarf::DW_EH_PE_pcrel; 348 TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 349 } 350 break; 351 case Triple::aarch64: 352 case Triple::aarch64_be: 353 // The small model guarantees static code/data size < 4GB, but not where it 354 // will be in memory. Most of these could end up >2GB away so even a signed 355 // pc-relative 32-bit address is insufficient, theoretically. 356 if (PositionIndependent) { 357 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 358 dwarf::DW_EH_PE_sdata8; 359 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 360 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 361 dwarf::DW_EH_PE_sdata8; 362 } else { 363 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 364 LSDAEncoding = dwarf::DW_EH_PE_absptr; 365 TTypeEncoding = dwarf::DW_EH_PE_absptr; 366 } 367 break; 368 case Triple::lanai: 369 LSDAEncoding = dwarf::DW_EH_PE_absptr; 370 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 371 TTypeEncoding = dwarf::DW_EH_PE_absptr; 372 break; 373 case Triple::mips: 374 case Triple::mipsel: 375 case Triple::mips64: 376 case Triple::mips64el: 377 // MIPS uses indirect pointer to refer personality functions and types, so 378 // that the eh_frame section can be read-only. DW.ref.personality will be 379 // generated for relocation. 380 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 381 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 382 // identify N64 from just a triple. 383 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 384 dwarf::DW_EH_PE_sdata4; 385 // We don't support PC-relative LSDA references in GAS so we use the default 386 // DW_EH_PE_absptr for those. 387 388 // FreeBSD must be explicit about the data size and using pcrel since it's 389 // assembler/linker won't do the automatic conversion that the Linux tools 390 // do. 391 if (T.isOSFreeBSD()) { 392 PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 393 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 394 } 395 break; 396 case Triple::ppc64: 397 case Triple::ppc64le: 398 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 399 dwarf::DW_EH_PE_udata8; 400 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8; 401 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 402 dwarf::DW_EH_PE_udata8; 403 break; 404 case Triple::sparcel: 405 case Triple::sparc: 406 if (PositionIndependent) { 407 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 408 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 409 dwarf::DW_EH_PE_sdata4; 410 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 411 dwarf::DW_EH_PE_sdata4; 412 } else { 413 LSDAEncoding = dwarf::DW_EH_PE_absptr; 414 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 415 TTypeEncoding = dwarf::DW_EH_PE_absptr; 416 } 417 break; 418 case Triple::sparcv9: 419 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 420 if (PositionIndependent) { 421 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 422 dwarf::DW_EH_PE_sdata4; 423 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 424 dwarf::DW_EH_PE_sdata4; 425 } else { 426 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 427 TTypeEncoding = dwarf::DW_EH_PE_absptr; 428 } 429 break; 430 case Triple::systemz: 431 // All currently-defined code models guarantee that 4-byte PC-relative 432 // values will be in range. 433 if (PositionIndependent) { 434 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 435 dwarf::DW_EH_PE_sdata4; 436 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 437 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 438 dwarf::DW_EH_PE_sdata4; 439 } else { 440 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 441 LSDAEncoding = dwarf::DW_EH_PE_absptr; 442 TTypeEncoding = dwarf::DW_EH_PE_absptr; 443 } 444 break; 445 default: 446 break; 447 } 448 449 unsigned EHSectionType = T.getArch() == Triple::x86_64 450 ? ELF::SHT_X86_64_UNWIND 451 : ELF::SHT_PROGBITS; 452 453 // Solaris requires different flags for .eh_frame to seemingly every other 454 // platform. 455 unsigned EHSectionFlags = ELF::SHF_ALLOC; 456 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 457 EHSectionFlags |= ELF::SHF_WRITE; 458 459 // ELF 460 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 461 ELF::SHF_WRITE | ELF::SHF_ALLOC); 462 463 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 464 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 465 466 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 467 ELF::SHF_WRITE | ELF::SHF_ALLOC); 468 469 ReadOnlySection = 470 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 471 472 TLSDataSection = 473 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 474 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 475 476 TLSBSSSection = Ctx->getELFSection( 477 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 478 479 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 480 ELF::SHF_ALLOC | ELF::SHF_WRITE); 481 482 MergeableConst4Section = 483 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 484 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 485 486 MergeableConst8Section = 487 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 488 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 489 490 MergeableConst16Section = 491 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 492 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 493 494 MergeableConst32Section = 495 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 496 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 497 498 // Exception Handling Sections. 499 500 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 501 // it contains relocatable pointers. In PIC mode, this is probably a big 502 // runtime hit for C++ apps. Either the contents of the LSDA need to be 503 // adjusted or this should be a data section. 504 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 505 ELF::SHF_ALLOC); 506 507 COFFDebugSymbolsSection = nullptr; 508 COFFDebugTypesSection = nullptr; 509 510 unsigned DebugSecType = ELF::SHT_PROGBITS; 511 512 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type 513 // to distinguish among sections contain DWARF and ECOFF debug formats. 514 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS. 515 if (T.getArch() == Triple::mips || T.getArch() == Triple::mipsel || 516 T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el) 517 DebugSecType = ELF::SHT_MIPS_DWARF; 518 519 // Debug Info Sections. 520 DwarfAbbrevSection = 521 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0); 522 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0); 523 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0); 524 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0); 525 DwarfPubNamesSection = 526 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0); 527 DwarfPubTypesSection = 528 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0); 529 DwarfGnuPubNamesSection = 530 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0); 531 DwarfGnuPubTypesSection = 532 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0); 533 DwarfStrSection = 534 Ctx->getELFSection(".debug_str", DebugSecType, 535 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 536 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0); 537 DwarfARangesSection = 538 Ctx->getELFSection(".debug_aranges", DebugSecType, 0); 539 DwarfRangesSection = 540 Ctx->getELFSection(".debug_ranges", DebugSecType, 0); 541 DwarfMacinfoSection = 542 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0); 543 544 // DWARF5 Experimental Debug Info 545 546 // Accelerator Tables 547 DwarfAccelNamesSection = 548 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 549 DwarfAccelObjCSection = 550 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 551 DwarfAccelNamespaceSection = 552 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 553 DwarfAccelTypesSection = 554 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 555 556 // Fission Sections 557 DwarfInfoDWOSection = 558 Ctx->getELFSection(".debug_info.dwo", DebugSecType, 0); 559 DwarfTypesDWOSection = 560 Ctx->getELFSection(".debug_types.dwo", DebugSecType, 0); 561 DwarfAbbrevDWOSection = 562 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, 0); 563 DwarfStrDWOSection = 564 Ctx->getELFSection(".debug_str.dwo", DebugSecType, 565 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 566 DwarfLineDWOSection = 567 Ctx->getELFSection(".debug_line.dwo", DebugSecType, 0); 568 DwarfLocDWOSection = 569 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, 0); 570 DwarfStrOffDWOSection = 571 Ctx->getELFSection(".debug_str_offsets.dwo", DebugSecType, 0); 572 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0); 573 574 // DWP Sections 575 DwarfCUIndexSection = 576 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0); 577 DwarfTUIndexSection = 578 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0); 579 580 StackMapSection = 581 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 582 583 FaultMapSection = 584 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 585 586 EHFrameSection = 587 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 588 } 589 590 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 591 EHFrameSection = Ctx->getCOFFSection( 592 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 593 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 594 SectionKind::getData()); 595 596 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 597 // used to indicate to the linker that the text segment contains thumb instructions 598 // and to set the ISA selection bit for calls accordingly. 599 const bool IsThumb = T.getArch() == Triple::thumb; 600 601 CommDirectiveSupportsAlignment = true; 602 603 // COFF 604 BSSSection = Ctx->getCOFFSection( 605 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 606 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 607 SectionKind::getBSS()); 608 TextSection = Ctx->getCOFFSection( 609 ".text", 610 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 611 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 612 COFF::IMAGE_SCN_MEM_READ, 613 SectionKind::getText()); 614 DataSection = Ctx->getCOFFSection( 615 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 616 COFF::IMAGE_SCN_MEM_WRITE, 617 SectionKind::getData()); 618 ReadOnlySection = Ctx->getCOFFSection( 619 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 620 SectionKind::getReadOnly()); 621 622 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 623 // though it contains relocatable pointers. In PIC mode, this is probably a 624 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 625 // adjusted or this should be a data section. 626 if (T.getArch() == Triple::x86_64) { 627 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 628 LSDASection = nullptr; 629 } else { 630 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 631 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 632 COFF::IMAGE_SCN_MEM_READ, 633 SectionKind::getReadOnly()); 634 } 635 636 // Debug info. 637 COFFDebugSymbolsSection = 638 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 639 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 640 COFF::IMAGE_SCN_MEM_READ), 641 SectionKind::getMetadata()); 642 COFFDebugTypesSection = 643 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 644 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 645 COFF::IMAGE_SCN_MEM_READ), 646 SectionKind::getMetadata()); 647 648 DwarfAbbrevSection = Ctx->getCOFFSection( 649 ".debug_abbrev", 650 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 651 COFF::IMAGE_SCN_MEM_READ, 652 SectionKind::getMetadata(), "section_abbrev"); 653 DwarfInfoSection = Ctx->getCOFFSection( 654 ".debug_info", 655 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 656 COFF::IMAGE_SCN_MEM_READ, 657 SectionKind::getMetadata(), "section_info"); 658 DwarfLineSection = Ctx->getCOFFSection( 659 ".debug_line", 660 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 661 COFF::IMAGE_SCN_MEM_READ, 662 SectionKind::getMetadata(), "section_line"); 663 664 DwarfFrameSection = Ctx->getCOFFSection( 665 ".debug_frame", 666 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 667 COFF::IMAGE_SCN_MEM_READ, 668 SectionKind::getMetadata()); 669 DwarfPubNamesSection = Ctx->getCOFFSection( 670 ".debug_pubnames", 671 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 672 COFF::IMAGE_SCN_MEM_READ, 673 SectionKind::getMetadata()); 674 DwarfPubTypesSection = Ctx->getCOFFSection( 675 ".debug_pubtypes", 676 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 677 COFF::IMAGE_SCN_MEM_READ, 678 SectionKind::getMetadata()); 679 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 680 ".debug_gnu_pubnames", 681 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 682 COFF::IMAGE_SCN_MEM_READ, 683 SectionKind::getMetadata()); 684 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 685 ".debug_gnu_pubtypes", 686 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 687 COFF::IMAGE_SCN_MEM_READ, 688 SectionKind::getMetadata()); 689 DwarfStrSection = Ctx->getCOFFSection( 690 ".debug_str", 691 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 692 COFF::IMAGE_SCN_MEM_READ, 693 SectionKind::getMetadata(), "info_string"); 694 DwarfLocSection = Ctx->getCOFFSection( 695 ".debug_loc", 696 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 697 COFF::IMAGE_SCN_MEM_READ, 698 SectionKind::getMetadata(), "section_debug_loc"); 699 DwarfARangesSection = Ctx->getCOFFSection( 700 ".debug_aranges", 701 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 702 COFF::IMAGE_SCN_MEM_READ, 703 SectionKind::getMetadata()); 704 DwarfRangesSection = Ctx->getCOFFSection( 705 ".debug_ranges", 706 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 707 COFF::IMAGE_SCN_MEM_READ, 708 SectionKind::getMetadata(), "debug_range"); 709 DwarfMacinfoSection = Ctx->getCOFFSection( 710 ".debug_macinfo", 711 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 712 COFF::IMAGE_SCN_MEM_READ, 713 SectionKind::getMetadata(), "debug_macinfo"); 714 DwarfInfoDWOSection = Ctx->getCOFFSection( 715 ".debug_info.dwo", 716 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 717 COFF::IMAGE_SCN_MEM_READ, 718 SectionKind::getMetadata(), "section_info_dwo"); 719 DwarfTypesDWOSection = Ctx->getCOFFSection( 720 ".debug_types.dwo", 721 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 722 COFF::IMAGE_SCN_MEM_READ, 723 SectionKind::getMetadata(), "section_types_dwo"); 724 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 725 ".debug_abbrev.dwo", 726 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 727 COFF::IMAGE_SCN_MEM_READ, 728 SectionKind::getMetadata(), "section_abbrev_dwo"); 729 DwarfStrDWOSection = Ctx->getCOFFSection( 730 ".debug_str.dwo", 731 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 732 COFF::IMAGE_SCN_MEM_READ, 733 SectionKind::getMetadata(), "skel_string"); 734 DwarfLineDWOSection = Ctx->getCOFFSection( 735 ".debug_line.dwo", 736 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 737 COFF::IMAGE_SCN_MEM_READ, 738 SectionKind::getMetadata()); 739 DwarfLocDWOSection = Ctx->getCOFFSection( 740 ".debug_loc.dwo", 741 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 742 COFF::IMAGE_SCN_MEM_READ, 743 SectionKind::getMetadata(), "skel_loc"); 744 DwarfStrOffDWOSection = Ctx->getCOFFSection( 745 ".debug_str_offsets.dwo", 746 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 747 COFF::IMAGE_SCN_MEM_READ, 748 SectionKind::getMetadata()); 749 DwarfAddrSection = Ctx->getCOFFSection( 750 ".debug_addr", 751 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 752 COFF::IMAGE_SCN_MEM_READ, 753 SectionKind::getMetadata(), "addr_sec"); 754 DwarfCUIndexSection = Ctx->getCOFFSection( 755 ".debug_cu_index", 756 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 757 COFF::IMAGE_SCN_MEM_READ, 758 SectionKind::getMetadata()); 759 DwarfTUIndexSection = Ctx->getCOFFSection( 760 ".debug_tu_index", 761 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 762 COFF::IMAGE_SCN_MEM_READ, 763 SectionKind::getMetadata()); 764 DwarfAccelNamesSection = Ctx->getCOFFSection( 765 ".apple_names", 766 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 767 COFF::IMAGE_SCN_MEM_READ, 768 SectionKind::getMetadata(), "names_begin"); 769 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 770 ".apple_namespaces", 771 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 772 COFF::IMAGE_SCN_MEM_READ, 773 SectionKind::getMetadata(), "namespac_begin"); 774 DwarfAccelTypesSection = Ctx->getCOFFSection( 775 ".apple_types", 776 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 777 COFF::IMAGE_SCN_MEM_READ, 778 SectionKind::getMetadata(), "types_begin"); 779 DwarfAccelObjCSection = Ctx->getCOFFSection( 780 ".apple_objc", 781 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 782 COFF::IMAGE_SCN_MEM_READ, 783 SectionKind::getMetadata(), "objc_begin"); 784 785 DrectveSection = Ctx->getCOFFSection( 786 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 787 SectionKind::getMetadata()); 788 789 PDataSection = Ctx->getCOFFSection( 790 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 791 SectionKind::getData()); 792 793 XDataSection = Ctx->getCOFFSection( 794 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 795 SectionKind::getData()); 796 797 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 798 SectionKind::getMetadata()); 799 800 TLSDataSection = Ctx->getCOFFSection( 801 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 802 COFF::IMAGE_SCN_MEM_WRITE, 803 SectionKind::getData()); 804 805 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 806 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 807 COFF::IMAGE_SCN_MEM_READ, 808 SectionKind::getReadOnly()); 809 } 810 811 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) { 812 // TODO: Set the section types and flags. 813 TextSection = Ctx->getWasmSection(".text", 0, 0); 814 DataSection = Ctx->getWasmSection(".data", 0, 0); 815 816 // TODO: Set the section types and flags. 817 DwarfLineSection = Ctx->getWasmSection(".debug_line", 0, 0); 818 DwarfStrSection = Ctx->getWasmSection(".debug_str", 0, 0); 819 DwarfLocSection = Ctx->getWasmSection(".debug_loc", 0, 0); 820 DwarfAbbrevSection = Ctx->getWasmSection(".debug_abbrev", 0, 0, "section_abbrev"); 821 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", 0, 0); 822 DwarfRangesSection = Ctx->getWasmSection(".debug_ranges", 0, 0, "debug_range"); 823 DwarfMacinfoSection = Ctx->getWasmSection(".debug_macinfo", 0, 0, "debug_macinfo"); 824 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", 0, 0); 825 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", 0, 0); 826 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", 0, 0); 827 DwarfInfoSection = Ctx->getWasmSection(".debug_info", 0, 0, "section_info"); 828 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", 0, 0); 829 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", 0, 0); 830 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", 0, 0); 831 832 // TODO: Define more sections. 833 } 834 835 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 836 CodeModel::Model cm, 837 MCContext &ctx) { 838 PositionIndependent = PIC; 839 CMModel = cm; 840 Ctx = &ctx; 841 842 // Common. 843 CommDirectiveSupportsAlignment = true; 844 SupportsWeakOmittedEHFrame = true; 845 SupportsCompactUnwindWithoutEHFrame = false; 846 OmitDwarfIfHaveCompactUnwind = false; 847 848 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 849 dwarf::DW_EH_PE_absptr; 850 851 CompactUnwindDwarfEHFrameOnly = 0; 852 853 EHFrameSection = nullptr; // Created on demand. 854 CompactUnwindSection = nullptr; // Used only by selected targets. 855 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 856 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 857 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 858 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 859 860 TT = TheTriple; 861 862 switch (TT.getObjectFormat()) { 863 case Triple::MachO: 864 Env = IsMachO; 865 initMachOMCObjectFileInfo(TT); 866 break; 867 case Triple::COFF: 868 if (!TT.isOSWindows()) 869 report_fatal_error( 870 "Cannot initialize MC for non-Windows COFF object files."); 871 872 Env = IsCOFF; 873 initCOFFMCObjectFileInfo(TT); 874 break; 875 case Triple::ELF: 876 Env = IsELF; 877 initELFMCObjectFileInfo(TT); 878 break; 879 case Triple::Wasm: 880 Env = IsWasm; 881 initWasmMCObjectFileInfo(TT); 882 break; 883 case Triple::UnknownObjectFormat: 884 report_fatal_error("Cannot initialize MC for unknown object file format."); 885 break; 886 } 887 } 888 889 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 890 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 891 0, utostr(Hash)); 892 } 893