lib/MC/MCObjectFileInfo.cpp

   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 using namespace llvm;
  20
  21 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
  22   // MachO
  23   IsFunctionEHFrameSymbolPrivate = false;
  24   SupportsWeakOmittedEHFrame = false;
  25
  26   if (T.isOSDarwin() &&
  27       (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))
  28     SupportsCompactUnwindWithoutEHFrame = true;
  29
  30   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  31     | dwarf::DW_EH_PE_sdata4;
  32   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  33   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  34     dwarf::DW_EH_PE_sdata4;
  35
  36   // .comm doesn't support alignment before Leopard.
  37   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  38     CommDirectiveSupportsAlignment = false;
  39
  40   TextSection // .text
  41     = Ctx->getMachOSection("__TEXT", "__text",
  42                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  43                            SectionKind::getText());
  44   DataSection // .data
  45     = Ctx->getMachOSection("__DATA", "__data", 0,
  46                            SectionKind::getDataRel());
  47
  48   // BSSSection might not be expected initialized on msvc.
  49   BSSSection = nullptr;
  50
  51   TLSDataSection // .tdata
  52     = Ctx->getMachOSection("__DATA", "__thread_data",
  53                            MachO::S_THREAD_LOCAL_REGULAR,
  54                            SectionKind::getDataRel());
  55   TLSBSSSection // .tbss
  56     = Ctx->getMachOSection("__DATA", "__thread_bss",
  57                            MachO::S_THREAD_LOCAL_ZEROFILL,
  58                            SectionKind::getThreadBSS());
  59
  60   // TODO: Verify datarel below.
  61   TLSTLVSection // .tlv
  62     = Ctx->getMachOSection("__DATA", "__thread_vars",
  63                            MachO::S_THREAD_LOCAL_VARIABLES,
  64                            SectionKind::getDataRel());
  65
  66   TLSThreadInitSection
  67     = Ctx->getMachOSection("__DATA", "__thread_init",
  68                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  69                           SectionKind::getDataRel());
  70
  71   CStringSection // .cstring
  72     = Ctx->getMachOSection("__TEXT", "__cstring",
  73                            MachO::S_CSTRING_LITERALS,
  74                            SectionKind::getMergeable1ByteCString());
  75   UStringSection
  76     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  77                            SectionKind::getMergeable2ByteCString());
  78   FourByteConstantSection // .literal4
  79     = Ctx->getMachOSection("__TEXT", "__literal4",
  80                            MachO::S_4BYTE_LITERALS,
  81                            SectionKind::getMergeableConst4());
  82   EightByteConstantSection // .literal8
  83     = Ctx->getMachOSection("__TEXT", "__literal8",
  84                            MachO::S_8BYTE_LITERALS,
  85                            SectionKind::getMergeableConst8());
  86
  87   SixteenByteConstantSection // .literal16
  88       = Ctx->getMachOSection("__TEXT", "__literal16",
  89                              MachO::S_16BYTE_LITERALS,
  90                              SectionKind::getMergeableConst16());
  91
  92   ReadOnlySection  // .const
  93     = Ctx->getMachOSection("__TEXT", "__const", 0,
  94                            SectionKind::getReadOnly());
  95
  96   TextCoalSection
  97     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
  98                            MachO::S_COALESCED |
  99                            MachO::S_ATTR_PURE_INSTRUCTIONS,
 100                            SectionKind::getText());
 101   ConstTextCoalSection
 102     = Ctx->getMachOSection("__TEXT", "__const_coal",
 103                            MachO::S_COALESCED,
 104                            SectionKind::getReadOnly());
 105   ConstDataSection  // .const_data
 106     = Ctx->getMachOSection("__DATA", "__const", 0,
 107                            SectionKind::getReadOnlyWithRel());
 108   DataCoalSection
 109     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 110                            MachO::S_COALESCED,
 111                            SectionKind::getDataRel());
 112   DataCommonSection
 113     = Ctx->getMachOSection("__DATA","__common",
 114                            MachO::S_ZEROFILL,
 115                            SectionKind::getBSS());
 116   DataBSSSection
 117     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 118                            SectionKind::getBSS());
 119
 120
 121   LazySymbolPointerSection
 122     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 123                            MachO::S_LAZY_SYMBOL_POINTERS,
 124                            SectionKind::getMetadata());
 125   NonLazySymbolPointerSection
 126     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 127                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 128                            SectionKind::getMetadata());
 129
 130   if (RelocM == Reloc::Static) {
 131     StaticCtorSection
 132       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 133                              SectionKind::getDataRel());
 134     StaticDtorSection
 135       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 136                              SectionKind::getDataRel());
 137   } else {
 138     StaticCtorSection
 139       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 140                              MachO::S_MOD_INIT_FUNC_POINTERS,
 141                              SectionKind::getDataRel());
 142     StaticDtorSection
 143       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 144                              MachO::S_MOD_TERM_FUNC_POINTERS,
 145                              SectionKind::getDataRel());
 146   }
 147
 148   // Exception Handling.
 149   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 150                                      SectionKind::getReadOnlyWithRel());
 151
 152   COFFDebugSymbolsSection = nullptr;
 153
 154   if ((T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) ||
 155       (T.isOSDarwin() &&
 156        (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))) {
 157     CompactUnwindSection =
 158       Ctx->getMachOSection("__LD", "__compact_unwind",
 159                            MachO::S_ATTR_DEBUG,
 160                            SectionKind::getReadOnly());
 161
 162     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 163       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 164     else if (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64)
 165       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 166   }
 167
 168   // Debug Information.
 169   DwarfAccelNamesSection =
 170     Ctx->getMachOSection("__DWARF", "__apple_names",
 171                          MachO::S_ATTR_DEBUG,
 172                          SectionKind::getMetadata());
 173   DwarfAccelObjCSection =
 174     Ctx->getMachOSection("__DWARF", "__apple_objc",
 175                          MachO::S_ATTR_DEBUG,
 176                          SectionKind::getMetadata());
 177   // 16 character section limit...
 178   DwarfAccelNamespaceSection =
 179     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 180                          MachO::S_ATTR_DEBUG,
 181                          SectionKind::getMetadata());
 182   DwarfAccelTypesSection =
 183     Ctx->getMachOSection("__DWARF", "__apple_types",
 184                          MachO::S_ATTR_DEBUG,
 185                          SectionKind::getMetadata());
 186
 187   DwarfAbbrevSection =
 188     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 189                          MachO::S_ATTR_DEBUG,
 190                          SectionKind::getMetadata());
 191   DwarfInfoSection =
 192     Ctx->getMachOSection("__DWARF", "__debug_info",
 193                          MachO::S_ATTR_DEBUG,
 194                          SectionKind::getMetadata());
 195   DwarfLineSection =
 196     Ctx->getMachOSection("__DWARF", "__debug_line",
 197                          MachO::S_ATTR_DEBUG,
 198                          SectionKind::getMetadata());
 199   DwarfFrameSection =
 200     Ctx->getMachOSection("__DWARF", "__debug_frame",
 201                          MachO::S_ATTR_DEBUG,
 202                          SectionKind::getMetadata());
 203   DwarfPubNamesSection =
 204     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 205                          MachO::S_ATTR_DEBUG,
 206                          SectionKind::getMetadata());
 207   DwarfPubTypesSection =
 208     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 209                          MachO::S_ATTR_DEBUG,
 210                          SectionKind::getMetadata());
 211   DwarfGnuPubNamesSection =
 212     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 213                          MachO::S_ATTR_DEBUG,
 214                          SectionKind::getMetadata());
 215   DwarfGnuPubTypesSection =
 216     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 217                          MachO::S_ATTR_DEBUG,
 218                          SectionKind::getMetadata());
 219   DwarfStrSection =
 220     Ctx->getMachOSection("__DWARF", "__debug_str",
 221                          MachO::S_ATTR_DEBUG,
 222                          SectionKind::getMetadata());
 223   DwarfLocSection =
 224     Ctx->getMachOSection("__DWARF", "__debug_loc",
 225                          MachO::S_ATTR_DEBUG,
 226                          SectionKind::getMetadata());
 227   DwarfARangesSection =
 228     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 229                          MachO::S_ATTR_DEBUG,
 230                          SectionKind::getMetadata());
 231   DwarfRangesSection =
 232     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 233                          MachO::S_ATTR_DEBUG,
 234                          SectionKind::getMetadata());
 235   DwarfMacroInfoSection =
 236     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 237                          MachO::S_ATTR_DEBUG,
 238                          SectionKind::getMetadata());
 239   DwarfDebugInlineSection =
 240     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 241                          MachO::S_ATTR_DEBUG,
 242                          SectionKind::getMetadata());
 243   StackMapSection =
 244     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 245                          SectionKind::getMetadata());
 246
 247   TLSExtraDataSection = TLSTLVSection;
 248 }
 249
 250 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 251   switch (T.getArch()) {
 252   case Triple::mips:
 253   case Triple::mipsel:
 254     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 255     break;
 256   case Triple::mips64:
 257   case Triple::mips64el:
 258     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 259     break;
 260   default:
 261     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 262     break;
 263   }
 264
 265   switch (T.getArch()) {
 266   case Triple::arm:
 267   case Triple::armeb:
 268   case Triple::thumb:
 269   case Triple::thumbeb:
 270     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 271       break;
 272     // Fallthrough if not using EHABI
 273   case Triple::x86:
 274     PersonalityEncoding = (RelocM == Reloc::PIC_)
 275      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 276      : dwarf::DW_EH_PE_absptr;
 277     LSDAEncoding = (RelocM == Reloc::PIC_)
 278       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 279       : dwarf::DW_EH_PE_absptr;
 280     TTypeEncoding = (RelocM == Reloc::PIC_)
 281      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 282      : dwarf::DW_EH_PE_absptr;
 283     break;
 284   case Triple::x86_64:
 285     if (RelocM == Reloc::PIC_) {
 286       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 287         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 288          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 289       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 290         (CMModel == CodeModel::Small
 291          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 292       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 293         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 294          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 295     } else {
 296       PersonalityEncoding =
 297         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 298         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 299       LSDAEncoding = (CMModel == CodeModel::Small)
 300         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 301       TTypeEncoding = (CMModel == CodeModel::Small)
 302         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 303     }
 304     break;
 305   case Triple::aarch64:
 306   case Triple::aarch64_be:
 307   case Triple::arm64:
 308   case Triple::arm64_be:
 309     // The small model guarantees static code/data size < 4GB, but not where it
 310     // will be in memory. Most of these could end up >2GB away so even a signed
 311     // pc-relative 32-bit address is insufficient, theoretically.
 312     if (RelocM == Reloc::PIC_) {
 313       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 314         dwarf::DW_EH_PE_sdata8;
 315       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 316       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 317         dwarf::DW_EH_PE_sdata8;
 318     } else {
 319       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 320       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 321       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 322     }
 323     break;
 324   case Triple::mips:
 325   case Triple::mipsel:
 326     // MIPS uses indirect pointer to refer personality functions, so that the
 327     // eh_frame section can be read-only.  DW.ref.personality will be generated
 328     // for relocation.
 329     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 330     break;
 331   case Triple::ppc64:
 332   case Triple::ppc64le:
 333     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 334       dwarf::DW_EH_PE_udata8;
 335     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 336     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 337       dwarf::DW_EH_PE_udata8;
 338     break;
 339   case Triple::sparc:
 340     if (RelocM == Reloc::PIC_) {
 341       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 342       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 343         dwarf::DW_EH_PE_sdata4;
 344       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 345         dwarf::DW_EH_PE_sdata4;
 346     } else {
 347       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 348       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 349       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 350     }
 351     break;
 352   case Triple::sparcv9:
 353     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 354     if (RelocM == Reloc::PIC_) {
 355       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 356         dwarf::DW_EH_PE_sdata4;
 357       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 358         dwarf::DW_EH_PE_sdata4;
 359     } else {
 360       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 361       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 362     }
 363     break;
 364   case Triple::systemz:
 365     // All currently-defined code models guarantee that 4-byte PC-relative
 366     // values will be in range.
 367     if (RelocM == Reloc::PIC_) {
 368       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 369         dwarf::DW_EH_PE_sdata4;
 370       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 371       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 372         dwarf::DW_EH_PE_sdata4;
 373     } else {
 374       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 375       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 376       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 377     }
 378     break;
 379   default:
 380     break;
 381   }
 382
 383   // Solaris requires different flags for .eh_frame to seemingly every other
 384   // platform.
 385   EHSectionType = ELF::SHT_PROGBITS;
 386   EHSectionFlags = ELF::SHF_ALLOC;
 387   if (T.getOS() == Triple::Solaris) {
 388     if (T.getArch() == Triple::x86_64)
 389       EHSectionType = ELF::SHT_X86_64_UNWIND;
 390     else
 391       EHSectionFlags |= ELF::SHF_WRITE;
 392   }
 393
 394
 395   // ELF
 396   BSSSection =
 397     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 398                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 399                        SectionKind::getBSS());
 400
 401   TextSection =
 402     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 403                        ELF::SHF_EXECINSTR |
 404                        ELF::SHF_ALLOC,
 405                        SectionKind::getText());
 406
 407   DataSection =
 408     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 409                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 410                        SectionKind::getDataRel());
 411
 412   ReadOnlySection =
 413     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 414                        ELF::SHF_ALLOC,
 415                        SectionKind::getReadOnly());
 416
 417   TLSDataSection =
 418     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 419                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 420                        ELF::SHF_WRITE,
 421                        SectionKind::getThreadData());
 422
 423   TLSBSSSection =
 424     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 425                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 426                        ELF::SHF_WRITE,
 427                        SectionKind::getThreadBSS());
 428
 429   DataRelSection =
 430     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 431                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 432                        SectionKind::getDataRel());
 433
 434   DataRelLocalSection =
 435     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 436                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 437                        SectionKind::getDataRelLocal());
 438
 439   DataRelROSection =
 440     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 441                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 442                        SectionKind::getReadOnlyWithRel());
 443
 444   DataRelROLocalSection =
 445     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 446                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 447                        SectionKind::getReadOnlyWithRelLocal());
 448
 449   MergeableConst4Section =
 450     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 451                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 452                        SectionKind::getMergeableConst4());
 453
 454   MergeableConst8Section =
 455     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 456                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 457                        SectionKind::getMergeableConst8());
 458
 459   MergeableConst16Section =
 460     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 461                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 462                        SectionKind::getMergeableConst16());
 463
 464   StaticCtorSection =
 465     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 466                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 467                        SectionKind::getDataRel());
 468
 469   StaticDtorSection =
 470     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 471                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 472                        SectionKind::getDataRel());
 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 =
 481     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 482                        ELF::SHF_ALLOC,
 483                        SectionKind::getReadOnly());
 484
 485   COFFDebugSymbolsSection = nullptr;
 486
 487   // Debug Info Sections.
 488   DwarfAbbrevSection =
 489     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 490                        SectionKind::getMetadata());
 491   DwarfInfoSection =
 492     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 493                        SectionKind::getMetadata());
 494   DwarfLineSection =
 495     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 496                        SectionKind::getMetadata());
 497   DwarfFrameSection =
 498     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 499                        SectionKind::getMetadata());
 500   DwarfPubNamesSection =
 501     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 502                        SectionKind::getMetadata());
 503   DwarfPubTypesSection =
 504     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 505                        SectionKind::getMetadata());
 506   DwarfGnuPubNamesSection =
 507     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 508                        SectionKind::getMetadata());
 509   DwarfGnuPubTypesSection =
 510     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 511                        SectionKind::getMetadata());
 512   DwarfStrSection =
 513     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 514                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 515                        SectionKind::getMergeable1ByteCString());
 516   DwarfLocSection =
 517     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 518                        SectionKind::getMetadata());
 519   DwarfARangesSection =
 520     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 521                        SectionKind::getMetadata());
 522   DwarfRangesSection =
 523     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 524                        SectionKind::getMetadata());
 525   DwarfMacroInfoSection =
 526     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 527                        SectionKind::getMetadata());
 528
 529   // DWARF5 Experimental Debug Info
 530
 531   // Accelerator Tables
 532   DwarfAccelNamesSection =
 533     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 534                        SectionKind::getMetadata());
 535   DwarfAccelObjCSection =
 536     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 537                        SectionKind::getMetadata());
 538   DwarfAccelNamespaceSection =
 539     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 540                        SectionKind::getMetadata());
 541   DwarfAccelTypesSection =
 542     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 543                        SectionKind::getMetadata());
 544
 545   // Fission Sections
 546   DwarfInfoDWOSection =
 547     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 548                        SectionKind::getMetadata());
 549   DwarfAbbrevDWOSection =
 550     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 551                        SectionKind::getMetadata());
 552   DwarfStrDWOSection =
 553     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 554                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 555                        SectionKind::getMergeable1ByteCString());
 556   DwarfLineDWOSection =
 557     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 558                        SectionKind::getMetadata());
 559   DwarfLocDWOSection =
 560     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 561                        SectionKind::getMetadata());
 562   DwarfStrOffDWOSection =
 563     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 564                        SectionKind::getMetadata());
 565   DwarfAddrSection =
 566     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 567                        SectionKind::getMetadata());
 568 }
 569
 570
 571 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 572   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 573
 574   // The object file format cannot represent common symbols with explicit
 575   // alignments.
 576   CommDirectiveSupportsAlignment = false;
 577
 578   // COFF
 579   BSSSection =
 580     Ctx->getCOFFSection(".bss",
 581                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 582                         COFF::IMAGE_SCN_MEM_READ |
 583                         COFF::IMAGE_SCN_MEM_WRITE,
 584                         SectionKind::getBSS());
 585   TextSection =
 586     Ctx->getCOFFSection(".text",
 587                         (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : 0) |
 588                         COFF::IMAGE_SCN_CNT_CODE |
 589                         COFF::IMAGE_SCN_MEM_EXECUTE |
 590                         COFF::IMAGE_SCN_MEM_READ,
 591                         SectionKind::getText());
 592   DataSection =
 593     Ctx->getCOFFSection(".data",
 594                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 595                         COFF::IMAGE_SCN_MEM_READ |
 596                         COFF::IMAGE_SCN_MEM_WRITE,
 597                         SectionKind::getDataRel());
 598   ReadOnlySection =
 599     Ctx->getCOFFSection(".rdata",
 600                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 601                         COFF::IMAGE_SCN_MEM_READ,
 602                         SectionKind::getReadOnly());
 603
 604   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 605     StaticCtorSection =
 606       Ctx->getCOFFSection(".CRT$XCU",
 607                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 608                           COFF::IMAGE_SCN_MEM_READ,
 609                           SectionKind::getReadOnly());
 610     StaticDtorSection =
 611       Ctx->getCOFFSection(".CRT$XTX",
 612                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 613                           COFF::IMAGE_SCN_MEM_READ,
 614                           SectionKind::getReadOnly());
 615   } else {
 616     StaticCtorSection =
 617       Ctx->getCOFFSection(".ctors",
 618                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 619                           COFF::IMAGE_SCN_MEM_READ |
 620                           COFF::IMAGE_SCN_MEM_WRITE,
 621                           SectionKind::getDataRel());
 622     StaticDtorSection =
 623       Ctx->getCOFFSection(".dtors",
 624                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 625                           COFF::IMAGE_SCN_MEM_READ |
 626                           COFF::IMAGE_SCN_MEM_WRITE,
 627                           SectionKind::getDataRel());
 628   }
 629
 630   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 631   // though it contains relocatable pointers.  In PIC mode, this is probably a
 632   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 633   // adjusted or this should be a data section.
 634   LSDASection =
 635     Ctx->getCOFFSection(".gcc_except_table",
 636                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 637                         COFF::IMAGE_SCN_MEM_READ,
 638                         SectionKind::getReadOnly());
 639
 640   // Debug info.
 641   COFFDebugSymbolsSection =
 642     Ctx->getCOFFSection(".debug$S",
 643                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 644                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 645                         COFF::IMAGE_SCN_MEM_READ,
 646                         SectionKind::getMetadata());
 647
 648   DwarfAbbrevSection =
 649     Ctx->getCOFFSection(".debug_abbrev",
 650                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 651                         COFF::IMAGE_SCN_MEM_READ,
 652                         SectionKind::getMetadata());
 653   DwarfInfoSection =
 654     Ctx->getCOFFSection(".debug_info",
 655                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 656                         COFF::IMAGE_SCN_MEM_READ,
 657                         SectionKind::getMetadata());
 658   DwarfLineSection =
 659     Ctx->getCOFFSection(".debug_line",
 660                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 661                         COFF::IMAGE_SCN_MEM_READ,
 662                         SectionKind::getMetadata());
 663   DwarfFrameSection =
 664     Ctx->getCOFFSection(".debug_frame",
 665                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 666                         COFF::IMAGE_SCN_MEM_READ,
 667                         SectionKind::getMetadata());
 668   DwarfPubNamesSection =
 669     Ctx->getCOFFSection(".debug_pubnames",
 670                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 671                         COFF::IMAGE_SCN_MEM_READ,
 672                         SectionKind::getMetadata());
 673   DwarfPubTypesSection =
 674     Ctx->getCOFFSection(".debug_pubtypes",
 675                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 676                         COFF::IMAGE_SCN_MEM_READ,
 677                         SectionKind::getMetadata());
 678   DwarfGnuPubNamesSection =
 679     Ctx->getCOFFSection(".debug_gnu_pubnames",
 680                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 681                         COFF::IMAGE_SCN_MEM_READ,
 682                         SectionKind::getMetadata());
 683   DwarfGnuPubTypesSection =
 684     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 685                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 686                         COFF::IMAGE_SCN_MEM_READ,
 687                         SectionKind::getMetadata());
 688   DwarfStrSection =
 689     Ctx->getCOFFSection(".debug_str",
 690                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 691                         COFF::IMAGE_SCN_MEM_READ,
 692                         SectionKind::getMetadata());
 693   DwarfLocSection =
 694     Ctx->getCOFFSection(".debug_loc",
 695                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 696                         COFF::IMAGE_SCN_MEM_READ,
 697                         SectionKind::getMetadata());
 698   DwarfARangesSection =
 699     Ctx->getCOFFSection(".debug_aranges",
 700                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 701                         COFF::IMAGE_SCN_MEM_READ,
 702                         SectionKind::getMetadata());
 703   DwarfRangesSection =
 704     Ctx->getCOFFSection(".debug_ranges",
 705                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 706                         COFF::IMAGE_SCN_MEM_READ,
 707                         SectionKind::getMetadata());
 708   DwarfMacroInfoSection =
 709     Ctx->getCOFFSection(".debug_macinfo",
 710                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 711                         COFF::IMAGE_SCN_MEM_READ,
 712                         SectionKind::getMetadata());
 713   DwarfInfoDWOSection =
 714       Ctx->getCOFFSection(".debug_info.dwo",
 715                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 716                           COFF::IMAGE_SCN_MEM_READ,
 717                           SectionKind::getMetadata());
 718   DwarfAbbrevDWOSection =
 719       Ctx->getCOFFSection(".debug_abbrev.dwo",
 720                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 721                           COFF::IMAGE_SCN_MEM_READ,
 722                           SectionKind::getMetadata());
 723   DwarfStrDWOSection =
 724       Ctx->getCOFFSection(".debug_str.dwo",
 725                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 726                           COFF::IMAGE_SCN_MEM_READ,
 727                           SectionKind::getMetadata());
 728   DwarfLineDWOSection =
 729       Ctx->getCOFFSection(".debug_line.dwo",
 730                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 731                           COFF::IMAGE_SCN_MEM_READ,
 732                           SectionKind::getMetadata());
 733   DwarfLocDWOSection =
 734       Ctx->getCOFFSection(".debug_loc.dwo",
 735                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 736                           COFF::IMAGE_SCN_MEM_READ,
 737                           SectionKind::getMetadata());
 738   DwarfStrOffDWOSection =
 739       Ctx->getCOFFSection(".debug_str_offsets.dwo",
 740                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 741                           COFF::IMAGE_SCN_MEM_READ,
 742                           SectionKind::getMetadata());
 743
 744   DwarfAddrSection =
 745     Ctx->getCOFFSection(".debug_addr",
 746                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 747                         COFF::IMAGE_SCN_MEM_READ,
 748                         SectionKind::getMetadata());
 749
 750   DrectveSection =
 751     Ctx->getCOFFSection(".drectve",
 752                         COFF::IMAGE_SCN_LNK_INFO |
 753                         COFF::IMAGE_SCN_LNK_REMOVE,
 754                         SectionKind::getMetadata());
 755
 756   PDataSection =
 757     Ctx->getCOFFSection(".pdata",
 758                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 759                         COFF::IMAGE_SCN_MEM_READ,
 760                         SectionKind::getDataRel());
 761
 762   XDataSection =
 763     Ctx->getCOFFSection(".xdata",
 764                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 765                         COFF::IMAGE_SCN_MEM_READ,
 766                         SectionKind::getDataRel());
 767
 768   TLSDataSection =
 769     Ctx->getCOFFSection(".tls$",
 770                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 771                         COFF::IMAGE_SCN_MEM_READ |
 772                         COFF::IMAGE_SCN_MEM_WRITE,
 773                         SectionKind::getDataRel());
 774 }
 775
 776 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 777                                             CodeModel::Model cm,
 778                                             MCContext &ctx) {
 779   RelocM = relocm;
 780   CMModel = cm;
 781   Ctx = &ctx;
 782
 783   // Common.
 784   CommDirectiveSupportsAlignment = true;
 785   SupportsWeakOmittedEHFrame = true;
 786   IsFunctionEHFrameSymbolPrivate = true;
 787   SupportsCompactUnwindWithoutEHFrame = false;
 788
 789   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 790       dwarf::DW_EH_PE_absptr;
 791
 792   CompactUnwindDwarfEHFrameOnly = 0;
 793
 794   EHFrameSection = nullptr;             // Created on demand.
 795   CompactUnwindSection = nullptr;       // Used only by selected targets.
 796   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 797   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 798   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 799   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 800
 801   Triple T(TT);
 802   Triple::ArchType Arch = T.getArch();
 803   // FIXME: Checking for Arch here to filter out bogus triples such as
 804   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 805   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 806        Arch == Triple::arm || Arch == Triple::thumb ||
 807        Arch == Triple::arm64 || Arch == Triple::aarch64 ||
 808        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 809        Arch == Triple::UnknownArch) &&
 810       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 811     Env = IsMachO;
 812     InitMachOMCObjectFileInfo(T);
 813   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 814               Arch == Triple::arm || Arch == Triple::thumb) &&
 815              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 816     Env = IsCOFF;
 817     InitCOFFMCObjectFileInfo(T);
 818   } else {
 819     Env = IsELF;
 820     InitELFMCObjectFileInfo(T);
 821   }
 822 }
 823
 824 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 825   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 826                             SectionKind::getMetadata(), 0, utostr(Hash));
 827 }
 828
 829 const MCSection *
 830 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 831   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 832                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 833                             utostr(Hash));
 834 }
 835
 836 void MCObjectFileInfo::InitEHFrameSection() {
 837   if (Env == IsMachO)
 838     EHFrameSection =
 839       Ctx->getMachOSection("__TEXT", "__eh_frame",
 840                            MachO::S_COALESCED |
 841                            MachO::S_ATTR_NO_TOC |
 842                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 843                            MachO::S_ATTR_LIVE_SUPPORT,
 844                            SectionKind::getReadOnly());
 845   else if (Env == IsELF)
 846     EHFrameSection =
 847       Ctx->getELFSection(".eh_frame", EHSectionType,
 848                          EHSectionFlags,
 849                          SectionKind::getDataRel());
 850   else
 851     EHFrameSection =
 852       Ctx->getCOFFSection(".eh_frame",
 853                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 854                           COFF::IMAGE_SCN_MEM_READ |
 855                           COFF::IMAGE_SCN_MEM_WRITE,
 856                           SectionKind::getDataRel());
 857 }