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/MCContext.h"
  14 #include "llvm/MC/MCSection.h"
  15 #include "llvm/MC/MCSectionCOFF.h"
  16 #include "llvm/MC/MCSectionELF.h"
  17 #include "llvm/MC/MCSectionMachO.h"
  18 using namespace llvm;
  19
  20 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
  21   // MachO
  22   IsFunctionEHFrameSymbolPrivate = false;
  23   SupportsWeakOmittedEHFrame = false;
  24
  25   if (T.isOSDarwin() && T.getArch() == Triple::arm64)
  26     SupportsCompactUnwindWithoutEHFrame = true;
  27
  28   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  29     | dwarf::DW_EH_PE_sdata4;
  30   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  31   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  32     dwarf::DW_EH_PE_sdata4;
  33
  34   // .comm doesn't support alignment before Leopard.
  35   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  36     CommDirectiveSupportsAlignment = false;
  37
  38   TextSection // .text
  39     = Ctx->getMachOSection("__TEXT", "__text",
  40                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  41                            SectionKind::getText());
  42   DataSection // .data
  43     = Ctx->getMachOSection("__DATA", "__data", 0,
  44                            SectionKind::getDataRel());
  45
  46   // BSSSection might not be expected initialized on msvc.
  47   BSSSection = nullptr;
  48
  49   TLSDataSection // .tdata
  50     = Ctx->getMachOSection("__DATA", "__thread_data",
  51                            MachO::S_THREAD_LOCAL_REGULAR,
  52                            SectionKind::getDataRel());
  53   TLSBSSSection // .tbss
  54     = Ctx->getMachOSection("__DATA", "__thread_bss",
  55                            MachO::S_THREAD_LOCAL_ZEROFILL,
  56                            SectionKind::getThreadBSS());
  57
  58   // TODO: Verify datarel below.
  59   TLSTLVSection // .tlv
  60     = Ctx->getMachOSection("__DATA", "__thread_vars",
  61                            MachO::S_THREAD_LOCAL_VARIABLES,
  62                            SectionKind::getDataRel());
  63
  64   TLSThreadInitSection
  65     = Ctx->getMachOSection("__DATA", "__thread_init",
  66                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  67                           SectionKind::getDataRel());
  68
  69   CStringSection // .cstring
  70     = Ctx->getMachOSection("__TEXT", "__cstring",
  71                            MachO::S_CSTRING_LITERALS,
  72                            SectionKind::getMergeable1ByteCString());
  73   UStringSection
  74     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  75                            SectionKind::getMergeable2ByteCString());
  76   FourByteConstantSection // .literal4
  77     = Ctx->getMachOSection("__TEXT", "__literal4",
  78                            MachO::S_4BYTE_LITERALS,
  79                            SectionKind::getMergeableConst4());
  80   EightByteConstantSection // .literal8
  81     = Ctx->getMachOSection("__TEXT", "__literal8",
  82                            MachO::S_8BYTE_LITERALS,
  83                            SectionKind::getMergeableConst8());
  84
  85   SixteenByteConstantSection // .literal16
  86       = Ctx->getMachOSection("__TEXT", "__literal16",
  87                              MachO::S_16BYTE_LITERALS,
  88                              SectionKind::getMergeableConst16());
  89
  90   ReadOnlySection  // .const
  91     = Ctx->getMachOSection("__TEXT", "__const", 0,
  92                            SectionKind::getReadOnly());
  93
  94   TextCoalSection
  95     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
  96                            MachO::S_COALESCED |
  97                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  98                            SectionKind::getText());
  99   ConstTextCoalSection
 100     = Ctx->getMachOSection("__TEXT", "__const_coal",
 101                            MachO::S_COALESCED,
 102                            SectionKind::getReadOnly());
 103   ConstDataSection  // .const_data
 104     = Ctx->getMachOSection("__DATA", "__const", 0,
 105                            SectionKind::getReadOnlyWithRel());
 106   DataCoalSection
 107     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 108                            MachO::S_COALESCED,
 109                            SectionKind::getDataRel());
 110   DataCommonSection
 111     = Ctx->getMachOSection("__DATA","__common",
 112                            MachO::S_ZEROFILL,
 113                            SectionKind::getBSS());
 114   DataBSSSection
 115     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 116                            SectionKind::getBSS());
 117
 118
 119   LazySymbolPointerSection
 120     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 121                            MachO::S_LAZY_SYMBOL_POINTERS,
 122                            SectionKind::getMetadata());
 123   NonLazySymbolPointerSection
 124     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 125                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 126                            SectionKind::getMetadata());
 127
 128   if (RelocM == Reloc::Static) {
 129     StaticCtorSection
 130       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 131                              SectionKind::getDataRel());
 132     StaticDtorSection
 133       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 134                              SectionKind::getDataRel());
 135   } else {
 136     StaticCtorSection
 137       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 138                              MachO::S_MOD_INIT_FUNC_POINTERS,
 139                              SectionKind::getDataRel());
 140     StaticDtorSection
 141       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 142                              MachO::S_MOD_TERM_FUNC_POINTERS,
 143                              SectionKind::getDataRel());
 144   }
 145
 146   // Exception Handling.
 147   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 148                                      SectionKind::getReadOnlyWithRel());
 149
 150   COFFDebugSymbolsSection = nullptr;
 151
 152   if ((T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) ||
 153       (T.isOSDarwin() && T.getArch() == Triple::arm64)) {
 154     CompactUnwindSection =
 155       Ctx->getMachOSection("__LD", "__compact_unwind",
 156                            MachO::S_ATTR_DEBUG,
 157                            SectionKind::getReadOnly());
 158
 159     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 160       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 161     else if (T.getArch() == Triple::arm64)
 162       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 163   }
 164
 165   // Debug Information.
 166   DwarfAccelNamesSection =
 167     Ctx->getMachOSection("__DWARF", "__apple_names",
 168                          MachO::S_ATTR_DEBUG,
 169                          SectionKind::getMetadata());
 170   DwarfAccelObjCSection =
 171     Ctx->getMachOSection("__DWARF", "__apple_objc",
 172                          MachO::S_ATTR_DEBUG,
 173                          SectionKind::getMetadata());
 174   // 16 character section limit...
 175   DwarfAccelNamespaceSection =
 176     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 177                          MachO::S_ATTR_DEBUG,
 178                          SectionKind::getMetadata());
 179   DwarfAccelTypesSection =
 180     Ctx->getMachOSection("__DWARF", "__apple_types",
 181                          MachO::S_ATTR_DEBUG,
 182                          SectionKind::getMetadata());
 183
 184   DwarfAbbrevSection =
 185     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 186                          MachO::S_ATTR_DEBUG,
 187                          SectionKind::getMetadata());
 188   DwarfInfoSection =
 189     Ctx->getMachOSection("__DWARF", "__debug_info",
 190                          MachO::S_ATTR_DEBUG,
 191                          SectionKind::getMetadata());
 192   DwarfLineSection =
 193     Ctx->getMachOSection("__DWARF", "__debug_line",
 194                          MachO::S_ATTR_DEBUG,
 195                          SectionKind::getMetadata());
 196   DwarfFrameSection =
 197     Ctx->getMachOSection("__DWARF", "__debug_frame",
 198                          MachO::S_ATTR_DEBUG,
 199                          SectionKind::getMetadata());
 200   DwarfPubNamesSection =
 201     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 202                          MachO::S_ATTR_DEBUG,
 203                          SectionKind::getMetadata());
 204   DwarfPubTypesSection =
 205     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 206                          MachO::S_ATTR_DEBUG,
 207                          SectionKind::getMetadata());
 208   DwarfGnuPubNamesSection =
 209     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 210                          MachO::S_ATTR_DEBUG,
 211                          SectionKind::getMetadata());
 212   DwarfGnuPubTypesSection =
 213     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 214                          MachO::S_ATTR_DEBUG,
 215                          SectionKind::getMetadata());
 216   DwarfStrSection =
 217     Ctx->getMachOSection("__DWARF", "__debug_str",
 218                          MachO::S_ATTR_DEBUG,
 219                          SectionKind::getMetadata());
 220   DwarfLocSection =
 221     Ctx->getMachOSection("__DWARF", "__debug_loc",
 222                          MachO::S_ATTR_DEBUG,
 223                          SectionKind::getMetadata());
 224   DwarfARangesSection =
 225     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 226                          MachO::S_ATTR_DEBUG,
 227                          SectionKind::getMetadata());
 228   DwarfRangesSection =
 229     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 230                          MachO::S_ATTR_DEBUG,
 231                          SectionKind::getMetadata());
 232   DwarfMacroInfoSection =
 233     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 234                          MachO::S_ATTR_DEBUG,
 235                          SectionKind::getMetadata());
 236   DwarfDebugInlineSection =
 237     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 238                          MachO::S_ATTR_DEBUG,
 239                          SectionKind::getMetadata());
 240   StackMapSection =
 241     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 242                          SectionKind::getMetadata());
 243
 244   TLSExtraDataSection = TLSTLVSection;
 245 }
 246
 247 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 248   switch (T.getArch()) {
 249   case Triple::mips:
 250   case Triple::mipsel:
 251     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 252     break;
 253   case Triple::mips64:
 254   case Triple::mips64el:
 255     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 256     break;
 257   default:
 258     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 259     break;
 260   }
 261
 262   switch (T.getArch()) {
 263   case Triple::arm:
 264   case Triple::armeb:
 265   case Triple::thumb:
 266   case Triple::thumbeb:
 267   case Triple::x86:
 268     PersonalityEncoding = (RelocM == Reloc::PIC_)
 269      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 270      : dwarf::DW_EH_PE_absptr;
 271     LSDAEncoding = (RelocM == Reloc::PIC_)
 272       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 273       : dwarf::DW_EH_PE_absptr;
 274     TTypeEncoding = (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     break;
 278   case Triple::x86_64:
 279     if (RelocM == Reloc::PIC_) {
 280       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 281         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 282          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 283       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 284         (CMModel == CodeModel::Small
 285          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 286       TTypeEncoding = 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     } else {
 290       PersonalityEncoding =
 291         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 292         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 293       LSDAEncoding = (CMModel == CodeModel::Small)
 294         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 295       TTypeEncoding = (CMModel == CodeModel::Small)
 296         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 297     }
 298     break;
 299   case Triple::aarch64:
 300   case Triple::aarch64_be:
 301   case Triple::arm64:
 302   case Triple::arm64_be:
 303     // The small model guarantees static code/data size < 4GB, but not where it
 304     // will be in memory. Most of these could end up >2GB away so even a signed
 305     // pc-relative 32-bit address is insufficient, theoretically.
 306     if (RelocM == Reloc::PIC_) {
 307       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 308         dwarf::DW_EH_PE_sdata8;
 309       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 310       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 311         dwarf::DW_EH_PE_sdata8;
 312     } else {
 313       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 314       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 315       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 316     }
 317     break;
 318   case Triple::ppc64:
 319   case Triple::ppc64le:
 320     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 321       dwarf::DW_EH_PE_udata8;
 322     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 323     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 324       dwarf::DW_EH_PE_udata8;
 325     break;
 326   case Triple::sparc:
 327     if (RelocM == Reloc::PIC_) {
 328       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 329       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 330         dwarf::DW_EH_PE_sdata4;
 331       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 332         dwarf::DW_EH_PE_sdata4;
 333     } else {
 334       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 335       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 336       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 337     }
 338     break;
 339   case Triple::sparcv9:
 340     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 341     if (RelocM == Reloc::PIC_) {
 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       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 348       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 349     }
 350     break;
 351   case Triple::systemz:
 352     // All currently-defined code models guarantee that 4-byte PC-relative
 353     // values will be in range.
 354     if (RelocM == Reloc::PIC_) {
 355       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 356         dwarf::DW_EH_PE_sdata4;
 357       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 358       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 359         dwarf::DW_EH_PE_sdata4;
 360     } else {
 361       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 362       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 363       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 364     }
 365     break;
 366   default:
 367     break;
 368   }
 369
 370   // Solaris requires different flags for .eh_frame to seemingly every other
 371   // platform.
 372   EHSectionType = ELF::SHT_PROGBITS;
 373   EHSectionFlags = ELF::SHF_ALLOC;
 374   if (T.getOS() == Triple::Solaris) {
 375     if (T.getArch() == Triple::x86_64)
 376       EHSectionType = ELF::SHT_X86_64_UNWIND;
 377     else
 378       EHSectionFlags |= ELF::SHF_WRITE;
 379   }
 380
 381
 382   // ELF
 383   BSSSection =
 384     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 385                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 386                        SectionKind::getBSS());
 387
 388   TextSection =
 389     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 390                        ELF::SHF_EXECINSTR |
 391                        ELF::SHF_ALLOC,
 392                        SectionKind::getText());
 393
 394   DataSection =
 395     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 396                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 397                        SectionKind::getDataRel());
 398
 399   ReadOnlySection =
 400     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 401                        ELF::SHF_ALLOC,
 402                        SectionKind::getReadOnly());
 403
 404   TLSDataSection =
 405     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 406                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 407                        ELF::SHF_WRITE,
 408                        SectionKind::getThreadData());
 409
 410   TLSBSSSection =
 411     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 412                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 413                        ELF::SHF_WRITE,
 414                        SectionKind::getThreadBSS());
 415
 416   DataRelSection =
 417     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 418                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 419                        SectionKind::getDataRel());
 420
 421   DataRelLocalSection =
 422     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 423                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 424                        SectionKind::getDataRelLocal());
 425
 426   DataRelROSection =
 427     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 428                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 429                        SectionKind::getReadOnlyWithRel());
 430
 431   DataRelROLocalSection =
 432     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 433                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 434                        SectionKind::getReadOnlyWithRelLocal());
 435
 436   MergeableConst4Section =
 437     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 438                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 439                        SectionKind::getMergeableConst4());
 440
 441   MergeableConst8Section =
 442     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 443                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 444                        SectionKind::getMergeableConst8());
 445
 446   MergeableConst16Section =
 447     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 448                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 449                        SectionKind::getMergeableConst16());
 450
 451   StaticCtorSection =
 452     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 453                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 454                        SectionKind::getDataRel());
 455
 456   StaticDtorSection =
 457     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 458                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 459                        SectionKind::getDataRel());
 460
 461   // Exception Handling Sections.
 462
 463   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 464   // it contains relocatable pointers.  In PIC mode, this is probably a big
 465   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 466   // adjusted or this should be a data section.
 467   LSDASection =
 468     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 469                        ELF::SHF_ALLOC,
 470                        SectionKind::getReadOnly());
 471
 472   COFFDebugSymbolsSection = nullptr;
 473
 474   // Debug Info Sections.
 475   DwarfAbbrevSection =
 476     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 477                        SectionKind::getMetadata());
 478   DwarfInfoSection =
 479     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 480                        SectionKind::getMetadata());
 481   DwarfLineSection =
 482     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 483                        SectionKind::getMetadata());
 484   DwarfFrameSection =
 485     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 486                        SectionKind::getMetadata());
 487   DwarfPubNamesSection =
 488     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 489                        SectionKind::getMetadata());
 490   DwarfPubTypesSection =
 491     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 492                        SectionKind::getMetadata());
 493   DwarfGnuPubNamesSection =
 494     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 495                        SectionKind::getMetadata());
 496   DwarfGnuPubTypesSection =
 497     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 498                        SectionKind::getMetadata());
 499   DwarfStrSection =
 500     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 501                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 502                        SectionKind::getMergeable1ByteCString());
 503   DwarfLocSection =
 504     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 505                        SectionKind::getMetadata());
 506   DwarfARangesSection =
 507     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 508                        SectionKind::getMetadata());
 509   DwarfRangesSection =
 510     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 511                        SectionKind::getMetadata());
 512   DwarfMacroInfoSection =
 513     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 514                        SectionKind::getMetadata());
 515
 516   // DWARF5 Experimental Debug Info
 517
 518   // Accelerator Tables
 519   DwarfAccelNamesSection =
 520     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 521                        SectionKind::getMetadata());
 522   DwarfAccelObjCSection =
 523     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 524                        SectionKind::getMetadata());
 525   DwarfAccelNamespaceSection =
 526     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 527                        SectionKind::getMetadata());
 528   DwarfAccelTypesSection =
 529     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 530                        SectionKind::getMetadata());
 531
 532   // Fission Sections
 533   DwarfInfoDWOSection =
 534     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 535                        SectionKind::getMetadata());
 536   DwarfAbbrevDWOSection =
 537     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 538                        SectionKind::getMetadata());
 539   DwarfStrDWOSection =
 540     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 541                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 542                        SectionKind::getMergeable1ByteCString());
 543   DwarfLineDWOSection =
 544     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 545                        SectionKind::getMetadata());
 546   DwarfLocDWOSection =
 547     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 548                        SectionKind::getMetadata());
 549   DwarfStrOffDWOSection =
 550     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 551                        SectionKind::getMetadata());
 552   DwarfAddrSection =
 553     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 554                        SectionKind::getMetadata());
 555 }
 556
 557
 558 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 559   // The object file format cannot represent common symbols with explicit
 560   // alignments.
 561   CommDirectiveSupportsAlignment = false;
 562
 563   // COFF
 564   BSSSection =
 565     Ctx->getCOFFSection(".bss",
 566                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 567                         COFF::IMAGE_SCN_MEM_READ |
 568                         COFF::IMAGE_SCN_MEM_WRITE,
 569                         SectionKind::getBSS());
 570   TextSection =
 571     Ctx->getCOFFSection(".text",
 572                         COFF::IMAGE_SCN_CNT_CODE |
 573                         COFF::IMAGE_SCN_MEM_EXECUTE |
 574                         COFF::IMAGE_SCN_MEM_READ,
 575                         SectionKind::getText());
 576   DataSection =
 577     Ctx->getCOFFSection(".data",
 578                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 579                         COFF::IMAGE_SCN_MEM_READ |
 580                         COFF::IMAGE_SCN_MEM_WRITE,
 581                         SectionKind::getDataRel());
 582   ReadOnlySection =
 583     Ctx->getCOFFSection(".rdata",
 584                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 585                         COFF::IMAGE_SCN_MEM_READ,
 586                         SectionKind::getReadOnly());
 587   if (T.isKnownWindowsMSVCEnvironment()) {
 588     StaticCtorSection =
 589       Ctx->getCOFFSection(".CRT$XCU",
 590                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 591                           COFF::IMAGE_SCN_MEM_READ,
 592                           SectionKind::getReadOnly());
 593   } else {
 594     StaticCtorSection =
 595       Ctx->getCOFFSection(".ctors",
 596                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 597                           COFF::IMAGE_SCN_MEM_READ |
 598                           COFF::IMAGE_SCN_MEM_WRITE,
 599                           SectionKind::getDataRel());
 600   }
 601
 602
 603   if (T.isKnownWindowsMSVCEnvironment()) {
 604     StaticDtorSection =
 605       Ctx->getCOFFSection(".CRT$XTX",
 606                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 607                           COFF::IMAGE_SCN_MEM_READ,
 608                           SectionKind::getReadOnly());
 609   } else {
 610     StaticDtorSection =
 611       Ctx->getCOFFSection(".dtors",
 612                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 613                           COFF::IMAGE_SCN_MEM_READ |
 614                           COFF::IMAGE_SCN_MEM_WRITE,
 615                           SectionKind::getDataRel());
 616   }
 617
 618   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 619   // though it contains relocatable pointers.  In PIC mode, this is probably a
 620   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 621   // adjusted or this should be a data section.
 622   LSDASection =
 623     Ctx->getCOFFSection(".gcc_except_table",
 624                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 625                         COFF::IMAGE_SCN_MEM_READ,
 626                         SectionKind::getReadOnly());
 627
 628   // Debug info.
 629   COFFDebugSymbolsSection =
 630     Ctx->getCOFFSection(".debug$S",
 631                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 632                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 633                         COFF::IMAGE_SCN_MEM_READ,
 634                         SectionKind::getMetadata());
 635
 636   DwarfAbbrevSection =
 637     Ctx->getCOFFSection(".debug_abbrev",
 638                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 639                         COFF::IMAGE_SCN_MEM_READ,
 640                         SectionKind::getMetadata());
 641   DwarfInfoSection =
 642     Ctx->getCOFFSection(".debug_info",
 643                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 644                         COFF::IMAGE_SCN_MEM_READ,
 645                         SectionKind::getMetadata());
 646   DwarfLineSection =
 647     Ctx->getCOFFSection(".debug_line",
 648                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 649                         COFF::IMAGE_SCN_MEM_READ,
 650                         SectionKind::getMetadata());
 651   DwarfFrameSection =
 652     Ctx->getCOFFSection(".debug_frame",
 653                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 654                         COFF::IMAGE_SCN_MEM_READ,
 655                         SectionKind::getMetadata());
 656   DwarfPubNamesSection =
 657     Ctx->getCOFFSection(".debug_pubnames",
 658                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 659                         COFF::IMAGE_SCN_MEM_READ,
 660                         SectionKind::getMetadata());
 661   DwarfPubTypesSection =
 662     Ctx->getCOFFSection(".debug_pubtypes",
 663                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 664                         COFF::IMAGE_SCN_MEM_READ,
 665                         SectionKind::getMetadata());
 666   DwarfGnuPubNamesSection =
 667     Ctx->getCOFFSection(".debug_gnu_pubnames",
 668                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 669                         COFF::IMAGE_SCN_MEM_READ,
 670                         SectionKind::getMetadata());
 671   DwarfGnuPubTypesSection =
 672     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 673                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 674                         COFF::IMAGE_SCN_MEM_READ,
 675                         SectionKind::getMetadata());
 676   DwarfStrSection =
 677     Ctx->getCOFFSection(".debug_str",
 678                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 679                         COFF::IMAGE_SCN_MEM_READ,
 680                         SectionKind::getMetadata());
 681   DwarfLocSection =
 682     Ctx->getCOFFSection(".debug_loc",
 683                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 684                         COFF::IMAGE_SCN_MEM_READ,
 685                         SectionKind::getMetadata());
 686   DwarfARangesSection =
 687     Ctx->getCOFFSection(".debug_aranges",
 688                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 689                         COFF::IMAGE_SCN_MEM_READ,
 690                         SectionKind::getMetadata());
 691   DwarfRangesSection =
 692     Ctx->getCOFFSection(".debug_ranges",
 693                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 694                         COFF::IMAGE_SCN_MEM_READ,
 695                         SectionKind::getMetadata());
 696   DwarfMacroInfoSection =
 697     Ctx->getCOFFSection(".debug_macinfo",
 698                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 699                         COFF::IMAGE_SCN_MEM_READ,
 700                         SectionKind::getMetadata());
 701   DwarfInfoDWOSection =
 702       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 703                                                 COFF::IMAGE_SCN_MEM_READ,
 704                           SectionKind::getMetadata());
 705   DwarfAbbrevDWOSection =
 706       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 707                                                   COFF::IMAGE_SCN_MEM_READ,
 708                           SectionKind::getMetadata());
 709   DwarfStrDWOSection =
 710       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 711                                                COFF::IMAGE_SCN_MEM_READ,
 712                           SectionKind::getMetadata());
 713   DwarfLineDWOSection =
 714       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 715                                                 COFF::IMAGE_SCN_MEM_READ,
 716                           SectionKind::getMetadata());
 717   DwarfLocDWOSection =
 718       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 719                                                COFF::IMAGE_SCN_MEM_READ,
 720                           SectionKind::getMetadata());
 721   DwarfStrOffDWOSection =
 722       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 723                                                   COFF::IMAGE_SCN_MEM_READ,
 724                           SectionKind::getMetadata());
 725   DwarfAddrSection = Ctx->getCOFFSection(
 726       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 727       SectionKind::getMetadata());
 728
 729   DrectveSection =
 730     Ctx->getCOFFSection(".drectve",
 731                         COFF::IMAGE_SCN_LNK_INFO,
 732                         SectionKind::getMetadata());
 733
 734   PDataSection =
 735     Ctx->getCOFFSection(".pdata",
 736                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 737                         COFF::IMAGE_SCN_MEM_READ,
 738                         SectionKind::getDataRel());
 739
 740   XDataSection =
 741     Ctx->getCOFFSection(".xdata",
 742                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 743                         COFF::IMAGE_SCN_MEM_READ,
 744                         SectionKind::getDataRel());
 745   TLSDataSection =
 746     Ctx->getCOFFSection(".tls$",
 747                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 748                         COFF::IMAGE_SCN_MEM_READ |
 749                         COFF::IMAGE_SCN_MEM_WRITE,
 750                         SectionKind::getDataRel());
 751 }
 752
 753 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 754                                             CodeModel::Model cm,
 755                                             MCContext &ctx) {
 756   RelocM = relocm;
 757   CMModel = cm;
 758   Ctx = &ctx;
 759
 760   // Common.
 761   CommDirectiveSupportsAlignment = true;
 762   SupportsWeakOmittedEHFrame = true;
 763   IsFunctionEHFrameSymbolPrivate = true;
 764   SupportsCompactUnwindWithoutEHFrame = false;
 765
 766   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 767       dwarf::DW_EH_PE_absptr;
 768
 769   CompactUnwindDwarfEHFrameOnly = 0;
 770
 771   EHFrameSection = nullptr;             // Created on demand.
 772   CompactUnwindSection = nullptr;       // Used only by selected targets.
 773   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 774   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 775   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 776   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 777
 778   Triple T(TT);
 779   Triple::ArchType Arch = T.getArch();
 780   // FIXME: Checking for Arch here to filter out bogus triples such as
 781   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 782   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 783        Arch == Triple::arm || Arch == Triple::thumb ||
 784        Arch == Triple::arm64 ||
 785        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 786        Arch == Triple::UnknownArch) &&
 787       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 788     Env = IsMachO;
 789     InitMachOMCObjectFileInfo(T);
 790   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 791               Arch == Triple::arm || Arch == Triple::thumb) &&
 792              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 793     Env = IsCOFF;
 794     InitCOFFMCObjectFileInfo(T);
 795   } else {
 796     Env = IsELF;
 797     InitELFMCObjectFileInfo(T);
 798   }
 799 }
 800
 801 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 802   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 803                             SectionKind::getMetadata(), 0, utostr(Hash));
 804 }
 805
 806 const MCSection *
 807 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 808   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 809                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 810                             utostr(Hash));
 811 }
 812
 813 void MCObjectFileInfo::InitEHFrameSection() {
 814   if (Env == IsMachO)
 815     EHFrameSection =
 816       Ctx->getMachOSection("__TEXT", "__eh_frame",
 817                            MachO::S_COALESCED |
 818                            MachO::S_ATTR_NO_TOC |
 819                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 820                            MachO::S_ATTR_LIVE_SUPPORT,
 821                            SectionKind::getReadOnly());
 822   else if (Env == IsELF)
 823     EHFrameSection =
 824       Ctx->getELFSection(".eh_frame", EHSectionType,
 825                          EHSectionFlags,
 826                          SectionKind::getDataRel());
 827   else
 828     EHFrameSection =
 829       Ctx->getCOFFSection(".eh_frame",
 830                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 831                           COFF::IMAGE_SCN_MEM_READ |
 832                           COFF::IMAGE_SCN_MEM_WRITE,
 833                           SectionKind::getDataRel());
 834 }