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