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