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 = FDEEncoding = 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::x86:
 264     PersonalityEncoding = (RelocM == Reloc::PIC_)
 265      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 266      : dwarf::DW_EH_PE_absptr;
 267     LSDAEncoding = (RelocM == Reloc::PIC_)
 268       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 269       : dwarf::DW_EH_PE_absptr;
 270     FDEEncoding = (RelocM == Reloc::PIC_)
 271       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 272       : dwarf::DW_EH_PE_absptr;
 273     TTypeEncoding = (RelocM == Reloc::PIC_)
 274      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 275      : dwarf::DW_EH_PE_absptr;
 276     break;
 277   case Triple::x86_64:
 278     if (RelocM == Reloc::PIC_) {
 279       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 280         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 281          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 282       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 283         (CMModel == CodeModel::Small
 284          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 285       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 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       FDEEncoding = dwarf::DW_EH_PE_udata4;
 296       TTypeEncoding = (CMModel == CodeModel::Small)
 297         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 298     }
 299     break;
 300   case Triple::aarch64:
 301   case Triple::aarch64_be:
 302   case Triple::arm64:
 303   case Triple::arm64_be:
 304     // The small model guarantees static code/data size < 4GB, but not where it
 305     // will be in memory. Most of these could end up >2GB away so even a signed
 306     // pc-relative 32-bit address is insufficient, theoretically.
 307     if (RelocM == Reloc::PIC_) {
 308       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 309         dwarf::DW_EH_PE_sdata8;
 310       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 311       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 312       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 313         dwarf::DW_EH_PE_sdata8;
 314     } else {
 315       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 316       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 317       FDEEncoding = dwarf::DW_EH_PE_udata4;
 318       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 319     }
 320     break;
 321   case Triple::ppc64:
 322   case Triple::ppc64le:
 323     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 324       dwarf::DW_EH_PE_udata8;
 325     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 326     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 327     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 328       dwarf::DW_EH_PE_udata8;
 329     break;
 330   case Triple::sparc:
 331     if (RelocM == Reloc::PIC_) {
 332       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 333       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 334         dwarf::DW_EH_PE_sdata4;
 335       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 336       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 337         dwarf::DW_EH_PE_sdata4;
 338     } else {
 339       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 340       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 341       FDEEncoding = dwarf::DW_EH_PE_udata4;
 342       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 343     }
 344   case Triple::sparcv9:
 345     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 346     if (RelocM == Reloc::PIC_) {
 347       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 348         dwarf::DW_EH_PE_sdata4;
 349       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 350       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 351         dwarf::DW_EH_PE_sdata4;
 352     } else {
 353       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 354       FDEEncoding = dwarf::DW_EH_PE_udata4;
 355       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 356     }
 357   case Triple::systemz:
 358     // All currently-defined code models guarantee that 4-byte PC-relative
 359     // values will be in range.
 360     if (RelocM == Reloc::PIC_) {
 361       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 362         dwarf::DW_EH_PE_sdata4;
 363       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 364       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 365       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 366         dwarf::DW_EH_PE_sdata4;
 367     } else {
 368       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 369       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 370       FDEEncoding = dwarf::DW_EH_PE_absptr;
 371       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 372     }
 373   default:
 374     break;
 375   }
 376
 377   // Solaris requires different flags for .eh_frame to seemingly every other
 378   // platform.
 379   EHSectionType = ELF::SHT_PROGBITS;
 380   EHSectionFlags = ELF::SHF_ALLOC;
 381   if (T.getOS() == Triple::Solaris) {
 382     if (T.getArch() == Triple::x86_64)
 383       EHSectionType = ELF::SHT_X86_64_UNWIND;
 384     else
 385       EHSectionFlags |= ELF::SHF_WRITE;
 386   }
 387
 388
 389   // ELF
 390   BSSSection =
 391     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 392                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 393                        SectionKind::getBSS());
 394
 395   TextSection =
 396     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 397                        ELF::SHF_EXECINSTR |
 398                        ELF::SHF_ALLOC,
 399                        SectionKind::getText());
 400
 401   DataSection =
 402     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 403                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 404                        SectionKind::getDataRel());
 405
 406   ReadOnlySection =
 407     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 408                        ELF::SHF_ALLOC,
 409                        SectionKind::getReadOnly());
 410
 411   TLSDataSection =
 412     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 413                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 414                        ELF::SHF_WRITE,
 415                        SectionKind::getThreadData());
 416
 417   TLSBSSSection =
 418     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 419                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 420                        ELF::SHF_WRITE,
 421                        SectionKind::getThreadBSS());
 422
 423   DataRelSection =
 424     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 425                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 426                        SectionKind::getDataRel());
 427
 428   DataRelLocalSection =
 429     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 430                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 431                        SectionKind::getDataRelLocal());
 432
 433   DataRelROSection =
 434     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 435                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 436                        SectionKind::getReadOnlyWithRel());
 437
 438   DataRelROLocalSection =
 439     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 440                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 441                        SectionKind::getReadOnlyWithRelLocal());
 442
 443   MergeableConst4Section =
 444     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 445                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 446                        SectionKind::getMergeableConst4());
 447
 448   MergeableConst8Section =
 449     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 450                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 451                        SectionKind::getMergeableConst8());
 452
 453   MergeableConst16Section =
 454     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 455                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 456                        SectionKind::getMergeableConst16());
 457
 458   StaticCtorSection =
 459     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 460                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 461                        SectionKind::getDataRel());
 462
 463   StaticDtorSection =
 464     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 465                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 466                        SectionKind::getDataRel());
 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 =
 475     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 476                        ELF::SHF_ALLOC,
 477                        SectionKind::getReadOnly());
 478
 479   COFFDebugSymbolsSection = nullptr;
 480
 481   // Debug Info Sections.
 482   DwarfAbbrevSection =
 483     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 484                        SectionKind::getMetadata());
 485   DwarfInfoSection =
 486     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 487                        SectionKind::getMetadata());
 488   DwarfLineSection =
 489     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 490                        SectionKind::getMetadata());
 491   DwarfFrameSection =
 492     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 493                        SectionKind::getMetadata());
 494   DwarfPubNamesSection =
 495     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 496                        SectionKind::getMetadata());
 497   DwarfPubTypesSection =
 498     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 499                        SectionKind::getMetadata());
 500   DwarfGnuPubNamesSection =
 501     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 502                        SectionKind::getMetadata());
 503   DwarfGnuPubTypesSection =
 504     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 505                        SectionKind::getMetadata());
 506   DwarfStrSection =
 507     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 508                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 509                        SectionKind::getMergeable1ByteCString());
 510   DwarfLocSection =
 511     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 512                        SectionKind::getMetadata());
 513   DwarfARangesSection =
 514     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 515                        SectionKind::getMetadata());
 516   DwarfRangesSection =
 517     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 518                        SectionKind::getMetadata());
 519   DwarfMacroInfoSection =
 520     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 521                        SectionKind::getMetadata());
 522
 523   // DWARF5 Experimental Debug Info
 524
 525   // Accelerator Tables
 526   DwarfAccelNamesSection =
 527     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 528                        SectionKind::getMetadata());
 529   DwarfAccelObjCSection =
 530     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 531                        SectionKind::getMetadata());
 532   DwarfAccelNamespaceSection =
 533     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 534                        SectionKind::getMetadata());
 535   DwarfAccelTypesSection =
 536     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 537                        SectionKind::getMetadata());
 538
 539   // Fission Sections
 540   DwarfInfoDWOSection =
 541     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 542                        SectionKind::getMetadata());
 543   DwarfAbbrevDWOSection =
 544     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 545                        SectionKind::getMetadata());
 546   DwarfStrDWOSection =
 547     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 548                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 549                        SectionKind::getMergeable1ByteCString());
 550   DwarfLineDWOSection =
 551     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 552                        SectionKind::getMetadata());
 553   DwarfLocDWOSection =
 554     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 555                        SectionKind::getMetadata());
 556   DwarfStrOffDWOSection =
 557     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 558                        SectionKind::getMetadata());
 559   DwarfAddrSection =
 560     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 561                        SectionKind::getMetadata());
 562 }
 563
 564
 565 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 566   // The object file format cannot represent common symbols with explicit
 567   // alignments.
 568   CommDirectiveSupportsAlignment = false;
 569
 570   // COFF
 571   BSSSection =
 572     Ctx->getCOFFSection(".bss",
 573                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 574                         COFF::IMAGE_SCN_MEM_READ |
 575                         COFF::IMAGE_SCN_MEM_WRITE,
 576                         SectionKind::getBSS());
 577   TextSection =
 578     Ctx->getCOFFSection(".text",
 579                         COFF::IMAGE_SCN_CNT_CODE |
 580                         COFF::IMAGE_SCN_MEM_EXECUTE |
 581                         COFF::IMAGE_SCN_MEM_READ,
 582                         SectionKind::getText());
 583   DataSection =
 584     Ctx->getCOFFSection(".data",
 585                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 586                         COFF::IMAGE_SCN_MEM_READ |
 587                         COFF::IMAGE_SCN_MEM_WRITE,
 588                         SectionKind::getDataRel());
 589   ReadOnlySection =
 590     Ctx->getCOFFSection(".rdata",
 591                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 592                         COFF::IMAGE_SCN_MEM_READ,
 593                         SectionKind::getReadOnly());
 594   if (T.isKnownWindowsMSVCEnvironment()) {
 595     StaticCtorSection =
 596       Ctx->getCOFFSection(".CRT$XCU",
 597                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 598                           COFF::IMAGE_SCN_MEM_READ,
 599                           SectionKind::getReadOnly());
 600   } else {
 601     StaticCtorSection =
 602       Ctx->getCOFFSection(".ctors",
 603                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 604                           COFF::IMAGE_SCN_MEM_READ |
 605                           COFF::IMAGE_SCN_MEM_WRITE,
 606                           SectionKind::getDataRel());
 607   }
 608
 609
 610   if (T.isKnownWindowsMSVCEnvironment()) {
 611     StaticDtorSection =
 612       Ctx->getCOFFSection(".CRT$XTX",
 613                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 614                           COFF::IMAGE_SCN_MEM_READ,
 615                           SectionKind::getReadOnly());
 616   } else {
 617     StaticDtorSection =
 618       Ctx->getCOFFSection(".dtors",
 619                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 620                           COFF::IMAGE_SCN_MEM_READ |
 621                           COFF::IMAGE_SCN_MEM_WRITE,
 622                           SectionKind::getDataRel());
 623   }
 624
 625   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 626   // though it contains relocatable pointers.  In PIC mode, this is probably a
 627   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 628   // adjusted or this should be a data section.
 629   LSDASection =
 630     Ctx->getCOFFSection(".gcc_except_table",
 631                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 632                         COFF::IMAGE_SCN_MEM_READ,
 633                         SectionKind::getReadOnly());
 634
 635   // Debug info.
 636   COFFDebugSymbolsSection =
 637     Ctx->getCOFFSection(".debug$S",
 638                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 639                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 640                         COFF::IMAGE_SCN_MEM_READ,
 641                         SectionKind::getMetadata());
 642
 643   DwarfAbbrevSection =
 644     Ctx->getCOFFSection(".debug_abbrev",
 645                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 646                         COFF::IMAGE_SCN_MEM_READ,
 647                         SectionKind::getMetadata());
 648   DwarfInfoSection =
 649     Ctx->getCOFFSection(".debug_info",
 650                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 651                         COFF::IMAGE_SCN_MEM_READ,
 652                         SectionKind::getMetadata());
 653   DwarfLineSection =
 654     Ctx->getCOFFSection(".debug_line",
 655                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 656                         COFF::IMAGE_SCN_MEM_READ,
 657                         SectionKind::getMetadata());
 658   DwarfFrameSection =
 659     Ctx->getCOFFSection(".debug_frame",
 660                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 661                         COFF::IMAGE_SCN_MEM_READ,
 662                         SectionKind::getMetadata());
 663   DwarfPubNamesSection =
 664     Ctx->getCOFFSection(".debug_pubnames",
 665                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 666                         COFF::IMAGE_SCN_MEM_READ,
 667                         SectionKind::getMetadata());
 668   DwarfPubTypesSection =
 669     Ctx->getCOFFSection(".debug_pubtypes",
 670                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 671                         COFF::IMAGE_SCN_MEM_READ,
 672                         SectionKind::getMetadata());
 673   DwarfGnuPubNamesSection =
 674     Ctx->getCOFFSection(".debug_gnu_pubnames",
 675                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 676                         COFF::IMAGE_SCN_MEM_READ,
 677                         SectionKind::getMetadata());
 678   DwarfGnuPubTypesSection =
 679     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 680                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 681                         COFF::IMAGE_SCN_MEM_READ,
 682                         SectionKind::getMetadata());
 683   DwarfStrSection =
 684     Ctx->getCOFFSection(".debug_str",
 685                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 686                         COFF::IMAGE_SCN_MEM_READ,
 687                         SectionKind::getMetadata());
 688   DwarfLocSection =
 689     Ctx->getCOFFSection(".debug_loc",
 690                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 691                         COFF::IMAGE_SCN_MEM_READ,
 692                         SectionKind::getMetadata());
 693   DwarfARangesSection =
 694     Ctx->getCOFFSection(".debug_aranges",
 695                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 696                         COFF::IMAGE_SCN_MEM_READ,
 697                         SectionKind::getMetadata());
 698   DwarfRangesSection =
 699     Ctx->getCOFFSection(".debug_ranges",
 700                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 701                         COFF::IMAGE_SCN_MEM_READ,
 702                         SectionKind::getMetadata());
 703   DwarfMacroInfoSection =
 704     Ctx->getCOFFSection(".debug_macinfo",
 705                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 706                         COFF::IMAGE_SCN_MEM_READ,
 707                         SectionKind::getMetadata());
 708   DwarfInfoDWOSection =
 709       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 710                                                 COFF::IMAGE_SCN_MEM_READ,
 711                           SectionKind::getMetadata());
 712   DwarfAbbrevDWOSection =
 713       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 714                                                   COFF::IMAGE_SCN_MEM_READ,
 715                           SectionKind::getMetadata());
 716   DwarfStrDWOSection =
 717       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 718                                                COFF::IMAGE_SCN_MEM_READ,
 719                           SectionKind::getMetadata());
 720   DwarfLineDWOSection =
 721       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 722                                                 COFF::IMAGE_SCN_MEM_READ,
 723                           SectionKind::getMetadata());
 724   DwarfLocDWOSection =
 725       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 726                                                COFF::IMAGE_SCN_MEM_READ,
 727                           SectionKind::getMetadata());
 728   DwarfStrOffDWOSection =
 729       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 730                                                   COFF::IMAGE_SCN_MEM_READ,
 731                           SectionKind::getMetadata());
 732   DwarfAddrSection = Ctx->getCOFFSection(
 733       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 734       SectionKind::getMetadata());
 735
 736   DrectveSection =
 737     Ctx->getCOFFSection(".drectve",
 738                         COFF::IMAGE_SCN_LNK_INFO,
 739                         SectionKind::getMetadata());
 740
 741   PDataSection =
 742     Ctx->getCOFFSection(".pdata",
 743                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 744                         COFF::IMAGE_SCN_MEM_READ,
 745                         SectionKind::getDataRel());
 746
 747   XDataSection =
 748     Ctx->getCOFFSection(".xdata",
 749                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 750                         COFF::IMAGE_SCN_MEM_READ,
 751                         SectionKind::getDataRel());
 752   TLSDataSection =
 753     Ctx->getCOFFSection(".tls$",
 754                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 755                         COFF::IMAGE_SCN_MEM_READ |
 756                         COFF::IMAGE_SCN_MEM_WRITE,
 757                         SectionKind::getDataRel());
 758 }
 759
 760 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 761                                             CodeModel::Model cm,
 762                                             MCContext &ctx) {
 763   RelocM = relocm;
 764   CMModel = cm;
 765   Ctx = &ctx;
 766
 767   // Common.
 768   CommDirectiveSupportsAlignment = true;
 769   SupportsWeakOmittedEHFrame = true;
 770   IsFunctionEHFrameSymbolPrivate = true;
 771   SupportsCompactUnwindWithoutEHFrame = false;
 772
 773   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
 774     TTypeEncoding = dwarf::DW_EH_PE_absptr;
 775
 776   CompactUnwindDwarfEHFrameOnly = 0;
 777
 778   EHFrameSection = nullptr;             // Created on demand.
 779   CompactUnwindSection = nullptr;       // Used only by selected targets.
 780   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 781   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 782   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 783   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 784
 785   Triple T(TT);
 786   Triple::ArchType Arch = T.getArch();
 787   // FIXME: Checking for Arch here to filter out bogus triples such as
 788   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 789   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 790        Arch == Triple::arm || Arch == Triple::thumb ||
 791        Arch == Triple::arm64 ||
 792        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 793        Arch == Triple::UnknownArch) &&
 794       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 795     Env = IsMachO;
 796     InitMachOMCObjectFileInfo(T);
 797   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 798               Arch == Triple::arm || Arch == Triple::thumb) &&
 799              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 800     Env = IsCOFF;
 801     InitCOFFMCObjectFileInfo(T);
 802   } else {
 803     Env = IsELF;
 804     InitELFMCObjectFileInfo(T);
 805   }
 806 }
 807
 808 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 809   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 810                             SectionKind::getMetadata(), 0, utostr(Hash));
 811 }
 812
 813 const MCSection *
 814 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 815   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 816                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 817                             utostr(Hash));
 818 }
 819
 820 void MCObjectFileInfo::InitEHFrameSection() {
 821   if (Env == IsMachO)
 822     EHFrameSection =
 823       Ctx->getMachOSection("__TEXT", "__eh_frame",
 824                            MachO::S_COALESCED |
 825                            MachO::S_ATTR_NO_TOC |
 826                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 827                            MachO::S_ATTR_LIVE_SUPPORT,
 828                            SectionKind::getReadOnly());
 829   else if (Env == IsELF)
 830     EHFrameSection =
 831       Ctx->getELFSection(".eh_frame", EHSectionType,
 832                          EHSectionFlags,
 833                          SectionKind::getDataRel());
 834   else
 835     EHFrameSection =
 836       Ctx->getCOFFSection(".eh_frame",
 837                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 838                           COFF::IMAGE_SCN_MEM_READ |
 839                           COFF::IMAGE_SCN_MEM_WRITE,
 840                           SectionKind::getDataRel());
 841 }