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(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 if (RelocM == Reloc::Static) { 181 StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0, 182 SectionKind::getData()); 183 StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0, 184 SectionKind::getData()); 185 } else { 186 StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func", 187 MachO::S_MOD_INIT_FUNC_POINTERS, 188 SectionKind::getData()); 189 StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func", 190 MachO::S_MOD_TERM_FUNC_POINTERS, 191 SectionKind::getData()); 192 } 193 194 // Exception Handling. 195 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 196 SectionKind::getReadOnlyWithRel()); 197 198 COFFDebugSymbolsSection = nullptr; 199 COFFDebugTypesSection = nullptr; 200 201 if (useCompactUnwind(T)) { 202 CompactUnwindSection = 203 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 204 SectionKind::getReadOnly()); 205 206 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 207 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 208 else if (T.getArch() == Triple::aarch64) 209 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 210 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 211 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 212 } 213 214 // Debug Information. 215 DwarfAccelNamesSection = 216 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 217 SectionKind::getMetadata(), "names_begin"); 218 DwarfAccelObjCSection = 219 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 220 SectionKind::getMetadata(), "objc_begin"); 221 // 16 character section limit... 222 DwarfAccelNamespaceSection = 223 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 224 SectionKind::getMetadata(), "namespac_begin"); 225 DwarfAccelTypesSection = 226 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 227 SectionKind::getMetadata(), "types_begin"); 228 229 DwarfAbbrevSection = 230 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 231 SectionKind::getMetadata(), "section_abbrev"); 232 DwarfInfoSection = 233 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 234 SectionKind::getMetadata(), "section_info"); 235 DwarfLineSection = 236 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 237 SectionKind::getMetadata(), "section_line"); 238 DwarfFrameSection = 239 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 240 SectionKind::getMetadata()); 241 DwarfPubNamesSection = 242 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 243 SectionKind::getMetadata()); 244 DwarfPubTypesSection = 245 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 246 SectionKind::getMetadata()); 247 DwarfGnuPubNamesSection = 248 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 249 SectionKind::getMetadata()); 250 DwarfGnuPubTypesSection = 251 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 252 SectionKind::getMetadata()); 253 DwarfStrSection = 254 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 255 SectionKind::getMetadata(), "info_string"); 256 DwarfLocSection = 257 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 258 SectionKind::getMetadata(), "section_debug_loc"); 259 DwarfARangesSection = 260 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 261 SectionKind::getMetadata()); 262 DwarfRangesSection = 263 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 264 SectionKind::getMetadata(), "debug_range"); 265 DwarfMacinfoSection = 266 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 267 SectionKind::getMetadata(), "debug_macinfo"); 268 DwarfDebugInlineSection = 269 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 270 SectionKind::getMetadata()); 271 DwarfCUIndexSection = 272 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 273 SectionKind::getMetadata()); 274 DwarfTUIndexSection = 275 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 276 SectionKind::getMetadata()); 277 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 278 0, SectionKind::getMetadata()); 279 280 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 281 0, SectionKind::getMetadata()); 282 283 TLSExtraDataSection = TLSTLVSection; 284 } 285 286 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) { 287 switch (T.getArch()) { 288 case Triple::mips: 289 case Triple::mipsel: 290 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 291 break; 292 case Triple::mips64: 293 case Triple::mips64el: 294 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 295 break; 296 case Triple::x86_64: 297 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 298 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 299 : dwarf::DW_EH_PE_sdata4); 300 break; 301 default: 302 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 303 break; 304 } 305 306 switch (T.getArch()) { 307 case Triple::arm: 308 case Triple::armeb: 309 case Triple::thumb: 310 case Triple::thumbeb: 311 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 312 break; 313 // Fallthrough if not using EHABI 314 case Triple::ppc: 315 case Triple::x86: 316 PersonalityEncoding = (RelocM == Reloc::PIC_) 317 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 318 : dwarf::DW_EH_PE_absptr; 319 LSDAEncoding = (RelocM == Reloc::PIC_) 320 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 321 : dwarf::DW_EH_PE_absptr; 322 TTypeEncoding = (RelocM == Reloc::PIC_) 323 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 324 : dwarf::DW_EH_PE_absptr; 325 break; 326 case Triple::x86_64: 327 if (RelocM == Reloc::PIC_) { 328 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 329 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 330 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 331 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 332 (CMModel == CodeModel::Small 333 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 334 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 335 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 336 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 337 } else { 338 PersonalityEncoding = 339 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 340 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 341 LSDAEncoding = (CMModel == CodeModel::Small) 342 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 343 TTypeEncoding = (CMModel == CodeModel::Small) 344 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 345 } 346 break; 347 case Triple::hexagon: 348 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 349 LSDAEncoding = dwarf::DW_EH_PE_absptr; 350 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 351 TTypeEncoding = dwarf::DW_EH_PE_absptr; 352 if (RelocM == Reloc::PIC_){ 353 PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 354 LSDAEncoding |= dwarf::DW_EH_PE_pcrel; 355 FDECFIEncoding |= dwarf::DW_EH_PE_pcrel; 356 TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 357 } 358 break; 359 case Triple::aarch64: 360 case Triple::aarch64_be: 361 // The small model guarantees static code/data size < 4GB, but not where it 362 // will be in memory. Most of these could end up >2GB away so even a signed 363 // pc-relative 32-bit address is insufficient, theoretically. 364 if (RelocM == Reloc::PIC_) { 365 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 366 dwarf::DW_EH_PE_sdata8; 367 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 368 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 369 dwarf::DW_EH_PE_sdata8; 370 } else { 371 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 372 LSDAEncoding = dwarf::DW_EH_PE_absptr; 373 TTypeEncoding = dwarf::DW_EH_PE_absptr; 374 } 375 break; 376 case Triple::lanai: 377 LSDAEncoding = dwarf::DW_EH_PE_absptr; 378 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 379 TTypeEncoding = dwarf::DW_EH_PE_absptr; 380 break; 381 case Triple::mips: 382 case Triple::mipsel: 383 case Triple::mips64: 384 case Triple::mips64el: 385 // MIPS uses indirect pointer to refer personality functions and types, so 386 // that the eh_frame section can be read-only. DW.ref.personality will be 387 // generated for relocation. 388 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 389 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 390 // identify N64 from just a triple. 391 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 392 dwarf::DW_EH_PE_sdata4; 393 // We don't support PC-relative LSDA references in GAS so we use the default 394 // DW_EH_PE_absptr for those. 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 (RelocM == Reloc::PIC_) { 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 (RelocM == Reloc::PIC_) { 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 (RelocM == Reloc::PIC_) { 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 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS, 499 ELF::SHF_ALLOC | ELF::SHF_WRITE); 500 501 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS, 502 ELF::SHF_ALLOC | ELF::SHF_WRITE); 503 504 // Exception Handling Sections. 505 506 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 507 // it contains relocatable pointers. In PIC mode, this is probably a big 508 // runtime hit for C++ apps. Either the contents of the LSDA need to be 509 // adjusted or this should be a data section. 510 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 511 ELF::SHF_ALLOC); 512 513 COFFDebugSymbolsSection = nullptr; 514 COFFDebugTypesSection = nullptr; 515 516 // Debug Info Sections. 517 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, 518 "section_abbrev"); 519 DwarfInfoSection = 520 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info"); 521 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0); 522 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0); 523 DwarfPubNamesSection = 524 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0); 525 DwarfPubTypesSection = 526 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0); 527 DwarfGnuPubNamesSection = 528 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0); 529 DwarfGnuPubTypesSection = 530 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0); 531 DwarfStrSection = 532 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 533 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 534 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0); 535 DwarfARangesSection = 536 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0); 537 DwarfRangesSection = 538 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range"); 539 DwarfMacinfoSection = Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 540 0, "debug_macinfo"); 541 542 // DWARF5 Experimental Debug Info 543 544 // Accelerator Tables 545 DwarfAccelNamesSection = 546 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin"); 547 DwarfAccelObjCSection = 548 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin"); 549 DwarfAccelNamespaceSection = Ctx->getELFSection( 550 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin"); 551 DwarfAccelTypesSection = 552 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin"); 553 554 // Fission Sections 555 DwarfInfoDWOSection = 556 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0); 557 DwarfTypesDWOSection = 558 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0); 559 DwarfAbbrevDWOSection = 560 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0); 561 DwarfStrDWOSection = 562 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS, 563 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 564 DwarfLineDWOSection = 565 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0); 566 DwarfLocDWOSection = 567 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc"); 568 DwarfStrOffDWOSection = 569 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0); 570 DwarfAddrSection = 571 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec"); 572 573 // DWP Sections 574 DwarfCUIndexSection = 575 Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0); 576 DwarfTUIndexSection = 577 Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0); 578 579 StackMapSection = 580 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 581 582 FaultMapSection = 583 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 584 585 EHFrameSection = 586 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 587 } 588 589 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) { 590 EHFrameSection = Ctx->getCOFFSection( 591 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 592 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 593 SectionKind::getData()); 594 595 bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb; 596 597 CommDirectiveSupportsAlignment = true; 598 599 // COFF 600 BSSSection = Ctx->getCOFFSection( 601 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 602 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 603 SectionKind::getBSS()); 604 TextSection = Ctx->getCOFFSection( 605 ".text", 606 (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 607 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 608 COFF::IMAGE_SCN_MEM_READ, 609 SectionKind::getText()); 610 DataSection = Ctx->getCOFFSection( 611 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 612 COFF::IMAGE_SCN_MEM_WRITE, 613 SectionKind::getData()); 614 ReadOnlySection = Ctx->getCOFFSection( 615 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 616 SectionKind::getReadOnly()); 617 618 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) { 619 StaticCtorSection = 620 Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 621 COFF::IMAGE_SCN_MEM_READ, 622 SectionKind::getReadOnly()); 623 StaticDtorSection = 624 Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 625 COFF::IMAGE_SCN_MEM_READ, 626 SectionKind::getReadOnly()); 627 } else { 628 StaticCtorSection = Ctx->getCOFFSection( 629 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 630 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 631 SectionKind::getData()); 632 StaticDtorSection = Ctx->getCOFFSection( 633 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 634 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 635 SectionKind::getData()); 636 } 637 638 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 639 // though it contains relocatable pointers. In PIC mode, this is probably a 640 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 641 // adjusted or this should be a data section. 642 if (T.getArch() == Triple::x86_64) { 643 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 644 LSDASection = nullptr; 645 } else { 646 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 647 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 648 COFF::IMAGE_SCN_MEM_READ, 649 SectionKind::getReadOnly()); 650 } 651 652 // Debug info. 653 COFFDebugSymbolsSection = 654 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 655 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 656 COFF::IMAGE_SCN_MEM_READ), 657 SectionKind::getMetadata()); 658 COFFDebugTypesSection = 659 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 660 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 661 COFF::IMAGE_SCN_MEM_READ), 662 SectionKind::getMetadata()); 663 664 DwarfAbbrevSection = Ctx->getCOFFSection( 665 ".debug_abbrev", 666 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 667 COFF::IMAGE_SCN_MEM_READ, 668 SectionKind::getMetadata(), "section_abbrev"); 669 DwarfInfoSection = Ctx->getCOFFSection( 670 ".debug_info", 671 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 672 COFF::IMAGE_SCN_MEM_READ, 673 SectionKind::getMetadata(), "section_info"); 674 DwarfLineSection = Ctx->getCOFFSection( 675 ".debug_line", 676 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 677 COFF::IMAGE_SCN_MEM_READ, 678 SectionKind::getMetadata(), "section_line"); 679 680 DwarfFrameSection = Ctx->getCOFFSection( 681 ".debug_frame", 682 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 683 COFF::IMAGE_SCN_MEM_READ, 684 SectionKind::getMetadata()); 685 DwarfPubNamesSection = Ctx->getCOFFSection( 686 ".debug_pubnames", 687 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 688 COFF::IMAGE_SCN_MEM_READ, 689 SectionKind::getMetadata()); 690 DwarfPubTypesSection = Ctx->getCOFFSection( 691 ".debug_pubtypes", 692 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 693 COFF::IMAGE_SCN_MEM_READ, 694 SectionKind::getMetadata()); 695 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 696 ".debug_gnu_pubnames", 697 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 698 COFF::IMAGE_SCN_MEM_READ, 699 SectionKind::getMetadata()); 700 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 701 ".debug_gnu_pubtypes", 702 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 703 COFF::IMAGE_SCN_MEM_READ, 704 SectionKind::getMetadata()); 705 DwarfStrSection = Ctx->getCOFFSection( 706 ".debug_str", 707 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 708 COFF::IMAGE_SCN_MEM_READ, 709 SectionKind::getMetadata(), "info_string"); 710 DwarfLocSection = Ctx->getCOFFSection( 711 ".debug_loc", 712 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 713 COFF::IMAGE_SCN_MEM_READ, 714 SectionKind::getMetadata(), "section_debug_loc"); 715 DwarfARangesSection = Ctx->getCOFFSection( 716 ".debug_aranges", 717 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 718 COFF::IMAGE_SCN_MEM_READ, 719 SectionKind::getMetadata()); 720 DwarfRangesSection = Ctx->getCOFFSection( 721 ".debug_ranges", 722 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 723 COFF::IMAGE_SCN_MEM_READ, 724 SectionKind::getMetadata(), "debug_range"); 725 DwarfMacinfoSection = Ctx->getCOFFSection( 726 ".debug_macinfo", 727 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 728 COFF::IMAGE_SCN_MEM_READ, 729 SectionKind::getMetadata(), "debug_macinfo"); 730 DwarfInfoDWOSection = Ctx->getCOFFSection( 731 ".debug_info.dwo", 732 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 733 COFF::IMAGE_SCN_MEM_READ, 734 SectionKind::getMetadata(), "section_info_dwo"); 735 DwarfTypesDWOSection = Ctx->getCOFFSection( 736 ".debug_types.dwo", 737 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 738 COFF::IMAGE_SCN_MEM_READ, 739 SectionKind::getMetadata(), "section_types_dwo"); 740 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 741 ".debug_abbrev.dwo", 742 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 743 COFF::IMAGE_SCN_MEM_READ, 744 SectionKind::getMetadata(), "section_abbrev_dwo"); 745 DwarfStrDWOSection = Ctx->getCOFFSection( 746 ".debug_str.dwo", 747 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 748 COFF::IMAGE_SCN_MEM_READ, 749 SectionKind::getMetadata(), "skel_string"); 750 DwarfLineDWOSection = Ctx->getCOFFSection( 751 ".debug_line.dwo", 752 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 753 COFF::IMAGE_SCN_MEM_READ, 754 SectionKind::getMetadata()); 755 DwarfLocDWOSection = Ctx->getCOFFSection( 756 ".debug_loc.dwo", 757 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 758 COFF::IMAGE_SCN_MEM_READ, 759 SectionKind::getMetadata(), "skel_loc"); 760 DwarfStrOffDWOSection = Ctx->getCOFFSection( 761 ".debug_str_offsets.dwo", 762 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 763 COFF::IMAGE_SCN_MEM_READ, 764 SectionKind::getMetadata()); 765 DwarfAddrSection = Ctx->getCOFFSection( 766 ".debug_addr", 767 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 768 COFF::IMAGE_SCN_MEM_READ, 769 SectionKind::getMetadata(), "addr_sec"); 770 DwarfCUIndexSection = Ctx->getCOFFSection( 771 ".debug_cu_index", 772 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 773 COFF::IMAGE_SCN_MEM_READ, 774 SectionKind::getMetadata()); 775 DwarfTUIndexSection = Ctx->getCOFFSection( 776 ".debug_tu_index", 777 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 778 COFF::IMAGE_SCN_MEM_READ, 779 SectionKind::getMetadata()); 780 DwarfAccelNamesSection = Ctx->getCOFFSection( 781 ".apple_names", 782 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 783 COFF::IMAGE_SCN_MEM_READ, 784 SectionKind::getMetadata(), "names_begin"); 785 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 786 ".apple_namespaces", 787 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 788 COFF::IMAGE_SCN_MEM_READ, 789 SectionKind::getMetadata(), "namespac_begin"); 790 DwarfAccelTypesSection = Ctx->getCOFFSection( 791 ".apple_types", 792 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 793 COFF::IMAGE_SCN_MEM_READ, 794 SectionKind::getMetadata(), "types_begin"); 795 DwarfAccelObjCSection = Ctx->getCOFFSection( 796 ".apple_objc", 797 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 798 COFF::IMAGE_SCN_MEM_READ, 799 SectionKind::getMetadata(), "objc_begin"); 800 801 DrectveSection = Ctx->getCOFFSection( 802 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 803 SectionKind::getMetadata()); 804 805 PDataSection = Ctx->getCOFFSection( 806 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 807 SectionKind::getData()); 808 809 XDataSection = Ctx->getCOFFSection( 810 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 811 SectionKind::getData()); 812 813 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 814 SectionKind::getMetadata()); 815 816 TLSDataSection = Ctx->getCOFFSection( 817 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 818 COFF::IMAGE_SCN_MEM_WRITE, 819 SectionKind::getData()); 820 821 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 822 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 823 COFF::IMAGE_SCN_MEM_READ, 824 SectionKind::getReadOnly()); 825 } 826 827 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, 828 Reloc::Model relocm, 829 CodeModel::Model cm, 830 MCContext &ctx) { 831 RelocM = relocm; 832 CMModel = cm; 833 Ctx = &ctx; 834 835 // Common. 836 CommDirectiveSupportsAlignment = true; 837 SupportsWeakOmittedEHFrame = true; 838 SupportsCompactUnwindWithoutEHFrame = false; 839 OmitDwarfIfHaveCompactUnwind = false; 840 841 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 842 dwarf::DW_EH_PE_absptr; 843 844 CompactUnwindDwarfEHFrameOnly = 0; 845 846 EHFrameSection = nullptr; // Created on demand. 847 CompactUnwindSection = nullptr; // Used only by selected targets. 848 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 849 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 850 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 851 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 852 853 TT = TheTriple; 854 855 switch (TT.getObjectFormat()) { 856 case Triple::MachO: 857 Env = IsMachO; 858 initMachOMCObjectFileInfo(TT); 859 break; 860 case Triple::COFF: 861 if (!TT.isOSWindows()) 862 report_fatal_error( 863 "Cannot initialize MC for non-Windows COFF object files."); 864 865 Env = IsCOFF; 866 initCOFFMCObjectFileInfo(TT); 867 break; 868 case Triple::ELF: 869 Env = IsELF; 870 initELFMCObjectFileInfo(TT); 871 break; 872 case Triple::UnknownObjectFormat: 873 report_fatal_error("Cannot initialize MC for unknown object file format."); 874 break; 875 } 876 } 877 878 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM, 879 CodeModel::Model CM, 880 MCContext &ctx) { 881 InitMCObjectFileInfo(Triple(TT), RM, CM, ctx); 882 } 883 884 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 885 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 886 0, utostr(Hash)); 887 } 888