1 //===-- MObjectFileInfo.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.isWatchOS()) 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.isWatchOS()) 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 if (RelocM == Reloc::Static) { 176 StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0, 177 SectionKind::getData()); 178 StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0, 179 SectionKind::getData()); 180 } else { 181 StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func", 182 MachO::S_MOD_INIT_FUNC_POINTERS, 183 SectionKind::getData()); 184 StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func", 185 MachO::S_MOD_TERM_FUNC_POINTERS, 186 SectionKind::getData()); 187 } 188 189 // Exception Handling. 190 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 191 SectionKind::getReadOnlyWithRel()); 192 193 COFFDebugSymbolsSection = nullptr; 194 195 if (useCompactUnwind(T)) { 196 CompactUnwindSection = 197 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 198 SectionKind::getReadOnly()); 199 200 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 201 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 202 else if (T.getArch() == Triple::aarch64) 203 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 204 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 205 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 206 } 207 208 // Debug Information. 209 DwarfAccelNamesSection = 210 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 211 SectionKind::getMetadata(), "names_begin"); 212 DwarfAccelObjCSection = 213 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 214 SectionKind::getMetadata(), "objc_begin"); 215 // 16 character section limit... 216 DwarfAccelNamespaceSection = 217 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 218 SectionKind::getMetadata(), "namespac_begin"); 219 DwarfAccelTypesSection = 220 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 221 SectionKind::getMetadata(), "types_begin"); 222 223 DwarfAbbrevSection = 224 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 225 SectionKind::getMetadata(), "section_abbrev"); 226 DwarfInfoSection = 227 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 228 SectionKind::getMetadata(), "section_info"); 229 DwarfLineSection = 230 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 231 SectionKind::getMetadata(), "section_line"); 232 DwarfFrameSection = 233 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 234 SectionKind::getMetadata()); 235 DwarfPubNamesSection = 236 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 237 SectionKind::getMetadata()); 238 DwarfPubTypesSection = 239 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 240 SectionKind::getMetadata()); 241 DwarfGnuPubNamesSection = 242 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 243 SectionKind::getMetadata()); 244 DwarfGnuPubTypesSection = 245 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 246 SectionKind::getMetadata()); 247 DwarfStrSection = 248 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 249 SectionKind::getMetadata(), "info_string"); 250 DwarfLocSection = 251 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 252 SectionKind::getMetadata(), "section_debug_loc"); 253 DwarfARangesSection = 254 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 255 SectionKind::getMetadata()); 256 DwarfRangesSection = 257 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 258 SectionKind::getMetadata(), "debug_range"); 259 DwarfDebugInlineSection = 260 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 261 SectionKind::getMetadata()); 262 DwarfCUIndexSection = 263 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 264 SectionKind::getMetadata()); 265 DwarfTUIndexSection = 266 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 267 SectionKind::getMetadata()); 268 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 269 0, SectionKind::getMetadata()); 270 271 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 272 0, SectionKind::getMetadata()); 273 274 TLSExtraDataSection = TLSTLVSection; 275 } 276 277 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) { 278 switch (T.getArch()) { 279 case Triple::mips: 280 case Triple::mipsel: 281 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 282 break; 283 case Triple::mips64: 284 case Triple::mips64el: 285 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 286 break; 287 case Triple::x86_64: 288 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 289 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 290 : dwarf::DW_EH_PE_sdata4); 291 break; 292 default: 293 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 294 break; 295 } 296 297 switch (T.getArch()) { 298 case Triple::arm: 299 case Triple::armeb: 300 case Triple::thumb: 301 case Triple::thumbeb: 302 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 303 break; 304 // Fallthrough if not using EHABI 305 case Triple::ppc: 306 case Triple::x86: 307 PersonalityEncoding = (RelocM == Reloc::PIC_) 308 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 309 : dwarf::DW_EH_PE_absptr; 310 LSDAEncoding = (RelocM == Reloc::PIC_) 311 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 312 : dwarf::DW_EH_PE_absptr; 313 TTypeEncoding = (RelocM == Reloc::PIC_) 314 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 315 : dwarf::DW_EH_PE_absptr; 316 break; 317 case Triple::x86_64: 318 if (RelocM == Reloc::PIC_) { 319 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 320 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 321 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 322 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 323 (CMModel == CodeModel::Small 324 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 325 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 326 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 327 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 328 } else { 329 PersonalityEncoding = 330 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 331 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 332 LSDAEncoding = (CMModel == CodeModel::Small) 333 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 334 TTypeEncoding = (CMModel == CodeModel::Small) 335 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 336 } 337 break; 338 case Triple::aarch64: 339 case Triple::aarch64_be: 340 // The small model guarantees static code/data size < 4GB, but not where it 341 // will be in memory. Most of these could end up >2GB away so even a signed 342 // pc-relative 32-bit address is insufficient, theoretically. 343 if (RelocM == Reloc::PIC_) { 344 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 345 dwarf::DW_EH_PE_sdata8; 346 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 347 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 348 dwarf::DW_EH_PE_sdata8; 349 } else { 350 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 351 LSDAEncoding = dwarf::DW_EH_PE_absptr; 352 TTypeEncoding = dwarf::DW_EH_PE_absptr; 353 } 354 break; 355 case Triple::mips: 356 case Triple::mipsel: 357 case Triple::mips64: 358 case Triple::mips64el: 359 // MIPS uses indirect pointer to refer personality functions and types, so 360 // that the eh_frame section can be read-only. DW.ref.personality will be 361 // generated for relocation. 362 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 363 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 364 // identify N64 from just a triple. 365 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 366 dwarf::DW_EH_PE_sdata4; 367 // We don't support PC-relative LSDA references in GAS so we use the default 368 // DW_EH_PE_absptr for those. 369 break; 370 case Triple::ppc64: 371 case Triple::ppc64le: 372 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 373 dwarf::DW_EH_PE_udata8; 374 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8; 375 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 376 dwarf::DW_EH_PE_udata8; 377 break; 378 case Triple::sparcel: 379 case Triple::sparc: 380 if (RelocM == Reloc::PIC_) { 381 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 382 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 383 dwarf::DW_EH_PE_sdata4; 384 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 385 dwarf::DW_EH_PE_sdata4; 386 } else { 387 LSDAEncoding = dwarf::DW_EH_PE_absptr; 388 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 389 TTypeEncoding = dwarf::DW_EH_PE_absptr; 390 } 391 break; 392 case Triple::sparcv9: 393 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 394 if (RelocM == Reloc::PIC_) { 395 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 396 dwarf::DW_EH_PE_sdata4; 397 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 398 dwarf::DW_EH_PE_sdata4; 399 } else { 400 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 401 TTypeEncoding = dwarf::DW_EH_PE_absptr; 402 } 403 break; 404 case Triple::systemz: 405 // All currently-defined code models guarantee that 4-byte PC-relative 406 // values will be in range. 407 if (RelocM == Reloc::PIC_) { 408 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 409 dwarf::DW_EH_PE_sdata4; 410 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 411 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 412 dwarf::DW_EH_PE_sdata4; 413 } else { 414 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 415 LSDAEncoding = dwarf::DW_EH_PE_absptr; 416 TTypeEncoding = dwarf::DW_EH_PE_absptr; 417 } 418 break; 419 default: 420 break; 421 } 422 423 unsigned EHSectionType = T.getArch() == Triple::x86_64 424 ? ELF::SHT_X86_64_UNWIND 425 : ELF::SHT_PROGBITS; 426 427 // Solaris requires different flags for .eh_frame to seemingly every other 428 // platform. 429 unsigned EHSectionFlags = ELF::SHF_ALLOC; 430 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 431 EHSectionFlags |= ELF::SHF_WRITE; 432 433 // ELF 434 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 435 ELF::SHF_WRITE | ELF::SHF_ALLOC); 436 437 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 438 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 439 440 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 441 ELF::SHF_WRITE | ELF::SHF_ALLOC); 442 443 ReadOnlySection = 444 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 445 446 TLSDataSection = 447 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 448 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 449 450 TLSBSSSection = Ctx->getELFSection( 451 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 452 453 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 454 ELF::SHF_ALLOC | ELF::SHF_WRITE); 455 456 MergeableConst4Section = 457 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 458 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 459 460 MergeableConst8Section = 461 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 462 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 463 464 MergeableConst16Section = 465 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 466 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 467 468 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS, 469 ELF::SHF_ALLOC | ELF::SHF_WRITE); 470 471 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS, 472 ELF::SHF_ALLOC | ELF::SHF_WRITE); 473 474 // Exception Handling Sections. 475 476 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 477 // it contains relocatable pointers. In PIC mode, this is probably a big 478 // runtime hit for C++ apps. Either the contents of the LSDA need to be 479 // adjusted or this should be a data section. 480 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 481 ELF::SHF_ALLOC); 482 483 COFFDebugSymbolsSection = nullptr; 484 485 // Debug Info Sections. 486 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, 487 "section_abbrev"); 488 DwarfInfoSection = 489 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info"); 490 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0); 491 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0); 492 DwarfPubNamesSection = 493 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0); 494 DwarfPubTypesSection = 495 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0); 496 DwarfGnuPubNamesSection = 497 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0); 498 DwarfGnuPubTypesSection = 499 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0); 500 DwarfStrSection = 501 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 502 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 503 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0); 504 DwarfARangesSection = 505 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0); 506 DwarfRangesSection = 507 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range"); 508 509 // DWARF5 Experimental Debug Info 510 511 // Accelerator Tables 512 DwarfAccelNamesSection = 513 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin"); 514 DwarfAccelObjCSection = 515 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin"); 516 DwarfAccelNamespaceSection = Ctx->getELFSection( 517 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin"); 518 DwarfAccelTypesSection = 519 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin"); 520 521 // Fission Sections 522 DwarfInfoDWOSection = 523 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0); 524 DwarfTypesDWOSection = 525 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0); 526 DwarfAbbrevDWOSection = 527 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0); 528 DwarfStrDWOSection = 529 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS, 530 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 531 DwarfLineDWOSection = 532 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0); 533 DwarfLocDWOSection = 534 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc"); 535 DwarfStrOffDWOSection = 536 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0); 537 DwarfAddrSection = 538 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec"); 539 540 // DWP Sections 541 DwarfCUIndexSection = 542 Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0); 543 DwarfTUIndexSection = 544 Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0); 545 546 StackMapSection = 547 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 548 549 FaultMapSection = 550 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 551 552 EHFrameSection = 553 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 554 } 555 556 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) { 557 EHFrameSection = Ctx->getCOFFSection( 558 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 559 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 560 SectionKind::getData()); 561 562 bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb; 563 564 CommDirectiveSupportsAlignment = true; 565 566 // COFF 567 BSSSection = Ctx->getCOFFSection( 568 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 569 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 570 SectionKind::getBSS()); 571 TextSection = Ctx->getCOFFSection( 572 ".text", 573 (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 574 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 575 COFF::IMAGE_SCN_MEM_READ, 576 SectionKind::getText()); 577 DataSection = Ctx->getCOFFSection( 578 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 579 COFF::IMAGE_SCN_MEM_WRITE, 580 SectionKind::getData()); 581 ReadOnlySection = Ctx->getCOFFSection( 582 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 583 SectionKind::getReadOnly()); 584 585 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) { 586 StaticCtorSection = 587 Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 588 COFF::IMAGE_SCN_MEM_READ, 589 SectionKind::getReadOnly()); 590 StaticDtorSection = 591 Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 592 COFF::IMAGE_SCN_MEM_READ, 593 SectionKind::getReadOnly()); 594 } else { 595 StaticCtorSection = Ctx->getCOFFSection( 596 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 597 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 598 SectionKind::getData()); 599 StaticDtorSection = Ctx->getCOFFSection( 600 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 601 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 602 SectionKind::getData()); 603 } 604 605 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 606 // though it contains relocatable pointers. In PIC mode, this is probably a 607 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 608 // adjusted or this should be a data section. 609 if (T.getArch() == Triple::x86_64) { 610 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 611 LSDASection = nullptr; 612 } else { 613 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 614 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 615 COFF::IMAGE_SCN_MEM_READ, 616 SectionKind::getReadOnly()); 617 } 618 619 // Debug info. 620 COFFDebugSymbolsSection = 621 Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE | 622 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 623 COFF::IMAGE_SCN_MEM_READ, 624 SectionKind::getMetadata()); 625 626 DwarfAbbrevSection = Ctx->getCOFFSection( 627 ".debug_abbrev", 628 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 629 COFF::IMAGE_SCN_MEM_READ, 630 SectionKind::getMetadata(), "section_abbrev"); 631 DwarfInfoSection = Ctx->getCOFFSection( 632 ".debug_info", 633 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 634 COFF::IMAGE_SCN_MEM_READ, 635 SectionKind::getMetadata(), "section_info"); 636 DwarfLineSection = Ctx->getCOFFSection( 637 ".debug_line", 638 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 639 COFF::IMAGE_SCN_MEM_READ, 640 SectionKind::getMetadata(), "section_line"); 641 642 DwarfFrameSection = Ctx->getCOFFSection( 643 ".debug_frame", 644 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 645 COFF::IMAGE_SCN_MEM_READ, 646 SectionKind::getMetadata()); 647 DwarfPubNamesSection = Ctx->getCOFFSection( 648 ".debug_pubnames", 649 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 650 COFF::IMAGE_SCN_MEM_READ, 651 SectionKind::getMetadata()); 652 DwarfPubTypesSection = Ctx->getCOFFSection( 653 ".debug_pubtypes", 654 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 655 COFF::IMAGE_SCN_MEM_READ, 656 SectionKind::getMetadata()); 657 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 658 ".debug_gnu_pubnames", 659 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 660 COFF::IMAGE_SCN_MEM_READ, 661 SectionKind::getMetadata()); 662 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 663 ".debug_gnu_pubtypes", 664 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 665 COFF::IMAGE_SCN_MEM_READ, 666 SectionKind::getMetadata()); 667 DwarfStrSection = Ctx->getCOFFSection( 668 ".debug_str", 669 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 670 COFF::IMAGE_SCN_MEM_READ, 671 SectionKind::getMetadata(), "info_string"); 672 DwarfLocSection = Ctx->getCOFFSection( 673 ".debug_loc", 674 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 675 COFF::IMAGE_SCN_MEM_READ, 676 SectionKind::getMetadata(), "section_debug_loc"); 677 DwarfARangesSection = Ctx->getCOFFSection( 678 ".debug_aranges", 679 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 680 COFF::IMAGE_SCN_MEM_READ, 681 SectionKind::getMetadata()); 682 DwarfRangesSection = Ctx->getCOFFSection( 683 ".debug_ranges", 684 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 685 COFF::IMAGE_SCN_MEM_READ, 686 SectionKind::getMetadata(), "debug_range"); 687 DwarfInfoDWOSection = Ctx->getCOFFSection( 688 ".debug_info.dwo", 689 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 690 COFF::IMAGE_SCN_MEM_READ, 691 SectionKind::getMetadata(), "section_info_dwo"); 692 DwarfTypesDWOSection = Ctx->getCOFFSection( 693 ".debug_types.dwo", 694 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 695 COFF::IMAGE_SCN_MEM_READ, 696 SectionKind::getMetadata(), "section_types_dwo"); 697 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 698 ".debug_abbrev.dwo", 699 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 700 COFF::IMAGE_SCN_MEM_READ, 701 SectionKind::getMetadata(), "section_abbrev_dwo"); 702 DwarfStrDWOSection = Ctx->getCOFFSection( 703 ".debug_str.dwo", 704 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 705 COFF::IMAGE_SCN_MEM_READ, 706 SectionKind::getMetadata(), "skel_string"); 707 DwarfLineDWOSection = Ctx->getCOFFSection( 708 ".debug_line.dwo", 709 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 710 COFF::IMAGE_SCN_MEM_READ, 711 SectionKind::getMetadata()); 712 DwarfLocDWOSection = Ctx->getCOFFSection( 713 ".debug_loc.dwo", 714 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 715 COFF::IMAGE_SCN_MEM_READ, 716 SectionKind::getMetadata(), "skel_loc"); 717 DwarfStrOffDWOSection = Ctx->getCOFFSection( 718 ".debug_str_offsets.dwo", 719 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 720 COFF::IMAGE_SCN_MEM_READ, 721 SectionKind::getMetadata()); 722 DwarfAddrSection = Ctx->getCOFFSection( 723 ".debug_addr", 724 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 725 COFF::IMAGE_SCN_MEM_READ, 726 SectionKind::getMetadata(), "addr_sec"); 727 DwarfCUIndexSection = Ctx->getCOFFSection( 728 ".debug_cu_index", 729 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 730 COFF::IMAGE_SCN_MEM_READ, 731 SectionKind::getMetadata()); 732 DwarfTUIndexSection = Ctx->getCOFFSection( 733 ".debug_tu_index", 734 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 735 COFF::IMAGE_SCN_MEM_READ, 736 SectionKind::getMetadata()); 737 DwarfAccelNamesSection = Ctx->getCOFFSection( 738 ".apple_names", 739 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 740 COFF::IMAGE_SCN_MEM_READ, 741 SectionKind::getMetadata(), "names_begin"); 742 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 743 ".apple_namespaces", 744 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 745 COFF::IMAGE_SCN_MEM_READ, 746 SectionKind::getMetadata(), "namespac_begin"); 747 DwarfAccelTypesSection = Ctx->getCOFFSection( 748 ".apple_types", 749 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 750 COFF::IMAGE_SCN_MEM_READ, 751 SectionKind::getMetadata(), "types_begin"); 752 DwarfAccelObjCSection = Ctx->getCOFFSection( 753 ".apple_objc", 754 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 755 COFF::IMAGE_SCN_MEM_READ, 756 SectionKind::getMetadata(), "objc_begin"); 757 758 DrectveSection = Ctx->getCOFFSection( 759 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 760 SectionKind::getMetadata()); 761 762 PDataSection = Ctx->getCOFFSection( 763 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 764 SectionKind::getData()); 765 766 XDataSection = Ctx->getCOFFSection( 767 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 768 SectionKind::getData()); 769 770 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 771 SectionKind::getMetadata()); 772 773 TLSDataSection = Ctx->getCOFFSection( 774 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 775 COFF::IMAGE_SCN_MEM_WRITE, 776 SectionKind::getData()); 777 778 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 779 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 780 COFF::IMAGE_SCN_MEM_READ, 781 SectionKind::getReadOnly()); 782 } 783 784 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, 785 Reloc::Model relocm, 786 CodeModel::Model cm, 787 MCContext &ctx) { 788 RelocM = relocm; 789 CMModel = cm; 790 Ctx = &ctx; 791 792 // Common. 793 CommDirectiveSupportsAlignment = true; 794 SupportsWeakOmittedEHFrame = true; 795 SupportsCompactUnwindWithoutEHFrame = false; 796 OmitDwarfIfHaveCompactUnwind = false; 797 798 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 799 dwarf::DW_EH_PE_absptr; 800 801 CompactUnwindDwarfEHFrameOnly = 0; 802 803 EHFrameSection = nullptr; // Created on demand. 804 CompactUnwindSection = nullptr; // Used only by selected targets. 805 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 806 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 807 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 808 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 809 810 TT = TheTriple; 811 812 switch (TT.getObjectFormat()) { 813 case Triple::MachO: 814 Env = IsMachO; 815 initMachOMCObjectFileInfo(TT); 816 break; 817 case Triple::COFF: 818 if (!TT.isOSWindows()) 819 report_fatal_error( 820 "Cannot initialize MC for non-Windows COFF object files."); 821 822 Env = IsCOFF; 823 initCOFFMCObjectFileInfo(TT); 824 break; 825 case Triple::ELF: 826 Env = IsELF; 827 initELFMCObjectFileInfo(TT); 828 break; 829 case Triple::UnknownObjectFormat: 830 report_fatal_error("Cannot initialize MC for unknown object file format."); 831 break; 832 } 833 } 834 835 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM, 836 CodeModel::Model CM, 837 MCContext &ctx) { 838 InitMCObjectFileInfo(Triple(TT), RM, CM, ctx); 839 } 840 841 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 842 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 843 0, utostr(Hash)); 844 } 845
