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   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  26     | dwarf::DW_EH_PE_sdata4;
  27   LSDAEncoding = FDEEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  28   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  29     dwarf::DW_EH_PE_sdata4;
  30
  31   // .comm doesn't support alignment before Leopard.
  32   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  33     CommDirectiveSupportsAlignment = false;
  34
  35   TextSection // .text
  36     = Ctx->getMachOSection("__TEXT", "__text",
  37                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  38                            SectionKind::getText());
  39   DataSection // .data
  40     = Ctx->getMachOSection("__DATA", "__data", 0,
  41                            SectionKind::getDataRel());
  42
  43   // BSSSection might not be expected initialized on msvc.
  44   BSSSection = 0;
  45
  46   TLSDataSection // .tdata
  47     = Ctx->getMachOSection("__DATA", "__thread_data",
  48                            MachO::S_THREAD_LOCAL_REGULAR,
  49                            SectionKind::getDataRel());
  50   TLSBSSSection // .tbss
  51     = Ctx->getMachOSection("__DATA", "__thread_bss",
  52                            MachO::S_THREAD_LOCAL_ZEROFILL,
  53                            SectionKind::getThreadBSS());
  54
  55   // TODO: Verify datarel below.
  56   TLSTLVSection // .tlv
  57     = Ctx->getMachOSection("__DATA", "__thread_vars",
  58                            MachO::S_THREAD_LOCAL_VARIABLES,
  59                            SectionKind::getDataRel());
  60
  61   TLSThreadInitSection
  62     = Ctx->getMachOSection("__DATA", "__thread_init",
  63                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  64                           SectionKind::getDataRel());
  65
  66   CStringSection // .cstring
  67     = Ctx->getMachOSection("__TEXT", "__cstring",
  68                            MachO::S_CSTRING_LITERALS,
  69                            SectionKind::getMergeable1ByteCString());
  70   UStringSection
  71     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  72                            SectionKind::getMergeable2ByteCString());
  73   FourByteConstantSection // .literal4
  74     = Ctx->getMachOSection("__TEXT", "__literal4",
  75                            MachO::S_4BYTE_LITERALS,
  76                            SectionKind::getMergeableConst4());
  77   EightByteConstantSection // .literal8
  78     = Ctx->getMachOSection("__TEXT", "__literal8",
  79                            MachO::S_8BYTE_LITERALS,
  80                            SectionKind::getMergeableConst8());
  81
  82   SixteenByteConstantSection // .literal16
  83       = Ctx->getMachOSection("__TEXT", "__literal16",
  84                              MachO::S_16BYTE_LITERALS,
  85                              SectionKind::getMergeableConst16());
  86
  87   ReadOnlySection  // .const
  88     = Ctx->getMachOSection("__TEXT", "__const", 0,
  89                            SectionKind::getReadOnly());
  90
  91   TextCoalSection
  92     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
  93                            MachO::S_COALESCED |
  94                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  95                            SectionKind::getText());
  96   ConstTextCoalSection
  97     = Ctx->getMachOSection("__TEXT", "__const_coal",
  98                            MachO::S_COALESCED,
  99                            SectionKind::getReadOnly());
 100   ConstDataSection  // .const_data
 101     = Ctx->getMachOSection("__DATA", "__const", 0,
 102                            SectionKind::getReadOnlyWithRel());
 103   DataCoalSection
 104     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 105                            MachO::S_COALESCED,
 106                            SectionKind::getDataRel());
 107   DataCommonSection
 108     = Ctx->getMachOSection("__DATA","__common",
 109                            MachO::S_ZEROFILL,
 110                            SectionKind::getBSS());
 111   DataBSSSection
 112     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 113                            SectionKind::getBSS());
 114
 115
 116   LazySymbolPointerSection
 117     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 118                            MachO::S_LAZY_SYMBOL_POINTERS,
 119                            SectionKind::getMetadata());
 120   NonLazySymbolPointerSection
 121     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 122                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 123                            SectionKind::getMetadata());
 124
 125   if (RelocM == Reloc::Static) {
 126     StaticCtorSection
 127       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 128                              SectionKind::getDataRel());
 129     StaticDtorSection
 130       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 131                              SectionKind::getDataRel());
 132   } else {
 133     StaticCtorSection
 134       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 135                              MachO::S_MOD_INIT_FUNC_POINTERS,
 136                              SectionKind::getDataRel());
 137     StaticDtorSection
 138       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 139                              MachO::S_MOD_TERM_FUNC_POINTERS,
 140                              SectionKind::getDataRel());
 141   }
 142
 143   // Exception Handling.
 144   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 145                                      SectionKind::getReadOnlyWithRel());
 146
 147   COFFDebugSymbolsSection = 0;
 148
 149   if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) {
 150     CompactUnwindSection =
 151       Ctx->getMachOSection("__LD", "__compact_unwind",
 152                            MachO::S_ATTR_DEBUG,
 153                            SectionKind::getReadOnly());
 154
 155     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 156       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 157   }
 158
 159   // Debug Information.
 160   DwarfAccelNamesSection =
 161     Ctx->getMachOSection("__DWARF", "__apple_names",
 162                          MachO::S_ATTR_DEBUG,
 163                          SectionKind::getMetadata());
 164   DwarfAccelObjCSection =
 165     Ctx->getMachOSection("__DWARF", "__apple_objc",
 166                          MachO::S_ATTR_DEBUG,
 167                          SectionKind::getMetadata());
 168   // 16 character section limit...
 169   DwarfAccelNamespaceSection =
 170     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 171                          MachO::S_ATTR_DEBUG,
 172                          SectionKind::getMetadata());
 173   DwarfAccelTypesSection =
 174     Ctx->getMachOSection("__DWARF", "__apple_types",
 175                          MachO::S_ATTR_DEBUG,
 176                          SectionKind::getMetadata());
 177
 178   DwarfAbbrevSection =
 179     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 180                          MachO::S_ATTR_DEBUG,
 181                          SectionKind::getMetadata());
 182   DwarfInfoSection =
 183     Ctx->getMachOSection("__DWARF", "__debug_info",
 184                          MachO::S_ATTR_DEBUG,
 185                          SectionKind::getMetadata());
 186   DwarfLineSection =
 187     Ctx->getMachOSection("__DWARF", "__debug_line",
 188                          MachO::S_ATTR_DEBUG,
 189                          SectionKind::getMetadata());
 190   DwarfFrameSection =
 191     Ctx->getMachOSection("__DWARF", "__debug_frame",
 192                          MachO::S_ATTR_DEBUG,
 193                          SectionKind::getMetadata());
 194   DwarfPubNamesSection =
 195     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 196                          MachO::S_ATTR_DEBUG,
 197                          SectionKind::getMetadata());
 198   DwarfPubTypesSection =
 199     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 200                          MachO::S_ATTR_DEBUG,
 201                          SectionKind::getMetadata());
 202   DwarfGnuPubNamesSection =
 203     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 204                          MachO::S_ATTR_DEBUG,
 205                          SectionKind::getMetadata());
 206   DwarfGnuPubTypesSection =
 207     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 208                          MachO::S_ATTR_DEBUG,
 209                          SectionKind::getMetadata());
 210   DwarfStrSection =
 211     Ctx->getMachOSection("__DWARF", "__debug_str",
 212                          MachO::S_ATTR_DEBUG,
 213                          SectionKind::getMetadata());
 214   DwarfLocSection =
 215     Ctx->getMachOSection("__DWARF", "__debug_loc",
 216                          MachO::S_ATTR_DEBUG,
 217                          SectionKind::getMetadata());
 218   DwarfARangesSection =
 219     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 220                          MachO::S_ATTR_DEBUG,
 221                          SectionKind::getMetadata());
 222   DwarfRangesSection =
 223     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 224                          MachO::S_ATTR_DEBUG,
 225                          SectionKind::getMetadata());
 226   DwarfMacroInfoSection =
 227     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 228                          MachO::S_ATTR_DEBUG,
 229                          SectionKind::getMetadata());
 230   DwarfDebugInlineSection =
 231     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 232                          MachO::S_ATTR_DEBUG,
 233                          SectionKind::getMetadata());
 234   StackMapSection =
 235     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 236                          SectionKind::getMetadata());
 237
 238   TLSExtraDataSection = TLSTLVSection;
 239 }
 240
 241 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 242   if (T.getArch() == Triple::mips ||
 243       T.getArch() == Triple::mipsel)
 244     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 245   else if (T.getArch() == Triple::mips64 ||
 246            T.getArch() == Triple::mips64el)
 247     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 248   else
 249     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 250
 251   if (T.getArch() == Triple::x86) {
 252     PersonalityEncoding = (RelocM == Reloc::PIC_)
 253      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 254      : dwarf::DW_EH_PE_absptr;
 255     LSDAEncoding = (RelocM == Reloc::PIC_)
 256       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 257       : dwarf::DW_EH_PE_absptr;
 258     FDEEncoding = (RelocM == Reloc::PIC_)
 259       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 260       : dwarf::DW_EH_PE_absptr;
 261     TTypeEncoding = (RelocM == Reloc::PIC_)
 262      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 263      : dwarf::DW_EH_PE_absptr;
 264   } else if (T.getArch() == Triple::x86_64) {
 265     if (RelocM == Reloc::PIC_) {
 266       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 267         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 268          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 269       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 270         (CMModel == CodeModel::Small
 271          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 272       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 273       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 274         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 275          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 276     } else {
 277       PersonalityEncoding =
 278         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 279         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 280       LSDAEncoding = (CMModel == CodeModel::Small)
 281         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 282       FDEEncoding = dwarf::DW_EH_PE_udata4;
 283       TTypeEncoding = (CMModel == CodeModel::Small)
 284         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 285     }
 286   }  else if (T.getArch() ==  Triple::aarch64) {
 287     // The small model guarantees static code/data size < 4GB, but not where it
 288     // will be in memory. Most of these could end up >2GB away so even a signed
 289     // pc-relative 32-bit address is insufficient, theoretically.
 290     if (RelocM == Reloc::PIC_) {
 291       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 292         dwarf::DW_EH_PE_sdata8;
 293       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 294       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 295       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 296         dwarf::DW_EH_PE_sdata8;
 297     } else {
 298       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 299       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 300       FDEEncoding = dwarf::DW_EH_PE_udata4;
 301       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 302     }
 303   } else if (T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le) {
 304     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 305       dwarf::DW_EH_PE_udata8;
 306     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 307     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 308     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 309       dwarf::DW_EH_PE_udata8;
 310   } else if (T.getArch() == Triple::sparc) {
 311     if (RelocM == Reloc::PIC_) {
 312       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 313       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 314         dwarf::DW_EH_PE_sdata4;
 315       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 316       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 317         dwarf::DW_EH_PE_sdata4;
 318     } else {
 319       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 320       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 321       FDEEncoding = dwarf::DW_EH_PE_udata4;
 322       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 323     }
 324   } else if (T.getArch() == Triple::sparcv9) {
 325     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 326     if (RelocM == Reloc::PIC_) {
 327       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 328         dwarf::DW_EH_PE_sdata4;
 329       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 330       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 331         dwarf::DW_EH_PE_sdata4;
 332     } else {
 333       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 334       FDEEncoding = dwarf::DW_EH_PE_udata4;
 335       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 336     }
 337   } else if (T.getArch() == Triple::systemz) {
 338     // All currently-defined code models guarantee that 4-byte PC-relative
 339     // values will be in range.
 340     if (RelocM == Reloc::PIC_) {
 341       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 342         dwarf::DW_EH_PE_sdata4;
 343       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 344       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 345       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 346         dwarf::DW_EH_PE_sdata4;
 347     } else {
 348       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 349       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 350       FDEEncoding = dwarf::DW_EH_PE_absptr;
 351       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 352     }
 353   }
 354
 355   // Solaris requires different flags for .eh_frame to seemingly every other
 356   // platform.
 357   EHSectionType = ELF::SHT_PROGBITS;
 358   EHSectionFlags = ELF::SHF_ALLOC;
 359   if (T.getOS() == Triple::Solaris) {
 360     if (T.getArch() == Triple::x86_64)
 361       EHSectionType = ELF::SHT_X86_64_UNWIND;
 362     else
 363       EHSectionFlags |= ELF::SHF_WRITE;
 364   }
 365
 366
 367   // ELF
 368   BSSSection =
 369     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 370                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 371                        SectionKind::getBSS());
 372
 373   TextSection =
 374     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 375                        ELF::SHF_EXECINSTR |
 376                        ELF::SHF_ALLOC,
 377                        SectionKind::getText());
 378
 379   DataSection =
 380     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 381                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 382                        SectionKind::getDataRel());
 383
 384   ReadOnlySection =
 385     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 386                        ELF::SHF_ALLOC,
 387                        SectionKind::getReadOnly());
 388
 389   TLSDataSection =
 390     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 391                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 392                        ELF::SHF_WRITE,
 393                        SectionKind::getThreadData());
 394
 395   TLSBSSSection =
 396     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 397                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 398                        ELF::SHF_WRITE,
 399                        SectionKind::getThreadBSS());
 400
 401   DataRelSection =
 402     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 403                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 404                        SectionKind::getDataRel());
 405
 406   DataRelLocalSection =
 407     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 408                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 409                        SectionKind::getDataRelLocal());
 410
 411   DataRelROSection =
 412     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 413                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 414                        SectionKind::getReadOnlyWithRel());
 415
 416   DataRelROLocalSection =
 417     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 418                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 419                        SectionKind::getReadOnlyWithRelLocal());
 420
 421   MergeableConst4Section =
 422     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 423                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 424                        SectionKind::getMergeableConst4());
 425
 426   MergeableConst8Section =
 427     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 428                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 429                        SectionKind::getMergeableConst8());
 430
 431   MergeableConst16Section =
 432     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 433                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 434                        SectionKind::getMergeableConst16());
 435
 436   StaticCtorSection =
 437     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 438                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 439                        SectionKind::getDataRel());
 440
 441   StaticDtorSection =
 442     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 443                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 444                        SectionKind::getDataRel());
 445
 446   // Exception Handling Sections.
 447
 448   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 449   // it contains relocatable pointers.  In PIC mode, this is probably a big
 450   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 451   // adjusted or this should be a data section.
 452   LSDASection =
 453     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 454                        ELF::SHF_ALLOC,
 455                        SectionKind::getReadOnly());
 456
 457   COFFDebugSymbolsSection = 0;
 458
 459   // Debug Info Sections.
 460   DwarfAbbrevSection =
 461     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 462                        SectionKind::getMetadata());
 463   DwarfInfoSection =
 464     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 465                        SectionKind::getMetadata());
 466   DwarfLineSection =
 467     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 468                        SectionKind::getMetadata());
 469   DwarfFrameSection =
 470     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 471                        SectionKind::getMetadata());
 472   DwarfPubNamesSection =
 473     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 474                        SectionKind::getMetadata());
 475   DwarfPubTypesSection =
 476     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 477                        SectionKind::getMetadata());
 478   DwarfGnuPubNamesSection =
 479     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 480                        SectionKind::getMetadata());
 481   DwarfGnuPubTypesSection =
 482     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 483                        SectionKind::getMetadata());
 484   DwarfStrSection =
 485     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 486                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 487                        SectionKind::getMergeable1ByteCString());
 488   DwarfLocSection =
 489     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 490                        SectionKind::getMetadata());
 491   DwarfARangesSection =
 492     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 493                        SectionKind::getMetadata());
 494   DwarfRangesSection =
 495     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 496                        SectionKind::getMetadata());
 497   DwarfMacroInfoSection =
 498     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 499                        SectionKind::getMetadata());
 500
 501   // DWARF5 Experimental Debug Info
 502
 503   // Accelerator Tables
 504   DwarfAccelNamesSection =
 505     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 506                        SectionKind::getMetadata());
 507   DwarfAccelObjCSection =
 508     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 509                        SectionKind::getMetadata());
 510   DwarfAccelNamespaceSection =
 511     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 512                        SectionKind::getMetadata());
 513   DwarfAccelTypesSection =
 514     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 515                        SectionKind::getMetadata());
 516
 517   // Fission Sections
 518   DwarfInfoDWOSection =
 519     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 520                        SectionKind::getMetadata());
 521   DwarfAbbrevDWOSection =
 522     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 523                        SectionKind::getMetadata());
 524   DwarfStrDWOSection =
 525     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 526                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 527                        SectionKind::getMergeable1ByteCString());
 528   DwarfLineDWOSection =
 529     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 530                        SectionKind::getMetadata());
 531   DwarfLocDWOSection =
 532     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 533                        SectionKind::getMetadata());
 534   DwarfStrOffDWOSection =
 535     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 536                        SectionKind::getMetadata());
 537   DwarfAddrSection =
 538     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 539                        SectionKind::getMetadata());
 540 }
 541
 542
 543 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 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                         COFF::IMAGE_SCN_CNT_CODE |
 554                         COFF::IMAGE_SCN_MEM_EXECUTE |
 555                         COFF::IMAGE_SCN_MEM_READ,
 556                         SectionKind::getText());
 557   DataSection =
 558     Ctx->getCOFFSection(".data",
 559                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 560                         COFF::IMAGE_SCN_MEM_READ |
 561                         COFF::IMAGE_SCN_MEM_WRITE,
 562                         SectionKind::getDataRel());
 563   ReadOnlySection =
 564     Ctx->getCOFFSection(".rdata",
 565                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 566                         COFF::IMAGE_SCN_MEM_READ,
 567                         SectionKind::getReadOnly());
 568   if (T.getOS() == Triple::Win32) {
 569     StaticCtorSection =
 570       Ctx->getCOFFSection(".CRT$XCU",
 571                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 572                           COFF::IMAGE_SCN_MEM_READ,
 573                           SectionKind::getReadOnly());
 574   } else {
 575     StaticCtorSection =
 576       Ctx->getCOFFSection(".ctors",
 577                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 578                           COFF::IMAGE_SCN_MEM_READ |
 579                           COFF::IMAGE_SCN_MEM_WRITE,
 580                           SectionKind::getDataRel());
 581   }
 582
 583
 584   if (T.getOS() == Triple::Win32) {
 585     StaticDtorSection =
 586       Ctx->getCOFFSection(".CRT$XTX",
 587                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 588                           COFF::IMAGE_SCN_MEM_READ,
 589                           SectionKind::getReadOnly());
 590   } else {
 591     StaticDtorSection =
 592       Ctx->getCOFFSection(".dtors",
 593                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 594                           COFF::IMAGE_SCN_MEM_READ |
 595                           COFF::IMAGE_SCN_MEM_WRITE,
 596                           SectionKind::getDataRel());
 597   }
 598
 599   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 600   // though it contains relocatable pointers.  In PIC mode, this is probably a
 601   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 602   // adjusted or this should be a data section.
 603   LSDASection =
 604     Ctx->getCOFFSection(".gcc_except_table",
 605                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 606                         COFF::IMAGE_SCN_MEM_READ,
 607                         SectionKind::getReadOnly());
 608
 609   // Debug info.
 610   COFFDebugSymbolsSection =
 611     Ctx->getCOFFSection(".debug$S",
 612                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 613                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 614                         COFF::IMAGE_SCN_MEM_READ,
 615                         SectionKind::getMetadata());
 616
 617   DwarfAbbrevSection =
 618     Ctx->getCOFFSection(".debug_abbrev",
 619                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 620                         COFF::IMAGE_SCN_MEM_READ,
 621                         SectionKind::getMetadata());
 622   DwarfInfoSection =
 623     Ctx->getCOFFSection(".debug_info",
 624                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 625                         COFF::IMAGE_SCN_MEM_READ,
 626                         SectionKind::getMetadata());
 627   DwarfLineSection =
 628     Ctx->getCOFFSection(".debug_line",
 629                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 630                         COFF::IMAGE_SCN_MEM_READ,
 631                         SectionKind::getMetadata());
 632   DwarfFrameSection =
 633     Ctx->getCOFFSection(".debug_frame",
 634                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 635                         COFF::IMAGE_SCN_MEM_READ,
 636                         SectionKind::getMetadata());
 637   DwarfPubNamesSection =
 638     Ctx->getCOFFSection(".debug_pubnames",
 639                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 640                         COFF::IMAGE_SCN_MEM_READ,
 641                         SectionKind::getMetadata());
 642   DwarfPubTypesSection =
 643     Ctx->getCOFFSection(".debug_pubtypes",
 644                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 645                         COFF::IMAGE_SCN_MEM_READ,
 646                         SectionKind::getMetadata());
 647   DwarfGnuPubNamesSection =
 648     Ctx->getCOFFSection(".debug_gnu_pubnames",
 649                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 650                         COFF::IMAGE_SCN_MEM_READ,
 651                         SectionKind::getMetadata());
 652   DwarfGnuPubTypesSection =
 653     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 654                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 655                         COFF::IMAGE_SCN_MEM_READ,
 656                         SectionKind::getMetadata());
 657   DwarfStrSection =
 658     Ctx->getCOFFSection(".debug_str",
 659                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 660                         COFF::IMAGE_SCN_MEM_READ,
 661                         SectionKind::getMetadata());
 662   DwarfLocSection =
 663     Ctx->getCOFFSection(".debug_loc",
 664                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 665                         COFF::IMAGE_SCN_MEM_READ,
 666                         SectionKind::getMetadata());
 667   DwarfARangesSection =
 668     Ctx->getCOFFSection(".debug_aranges",
 669                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 670                         COFF::IMAGE_SCN_MEM_READ,
 671                         SectionKind::getMetadata());
 672   DwarfRangesSection =
 673     Ctx->getCOFFSection(".debug_ranges",
 674                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 675                         COFF::IMAGE_SCN_MEM_READ,
 676                         SectionKind::getMetadata());
 677   DwarfMacroInfoSection =
 678     Ctx->getCOFFSection(".debug_macinfo",
 679                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 680                         COFF::IMAGE_SCN_MEM_READ,
 681                         SectionKind::getMetadata());
 682   DwarfInfoDWOSection =
 683       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 684                                                 COFF::IMAGE_SCN_MEM_READ,
 685                           SectionKind::getMetadata());
 686   DwarfAbbrevDWOSection =
 687       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 688                                                   COFF::IMAGE_SCN_MEM_READ,
 689                           SectionKind::getMetadata());
 690   DwarfStrDWOSection =
 691       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 692                                                COFF::IMAGE_SCN_MEM_READ,
 693                           SectionKind::getMetadata());
 694   DwarfLineDWOSection =
 695       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 696                                                 COFF::IMAGE_SCN_MEM_READ,
 697                           SectionKind::getMetadata());
 698   DwarfLocDWOSection =
 699       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 700                                                COFF::IMAGE_SCN_MEM_READ,
 701                           SectionKind::getMetadata());
 702   DwarfStrOffDWOSection =
 703       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 704                                                   COFF::IMAGE_SCN_MEM_READ,
 705                           SectionKind::getMetadata());
 706   DwarfAddrSection = Ctx->getCOFFSection(
 707       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 708       SectionKind::getMetadata());
 709
 710   DrectveSection =
 711     Ctx->getCOFFSection(".drectve",
 712                         COFF::IMAGE_SCN_LNK_INFO,
 713                         SectionKind::getMetadata());
 714
 715   PDataSection =
 716     Ctx->getCOFFSection(".pdata",
 717                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 718                         COFF::IMAGE_SCN_MEM_READ,
 719                         SectionKind::getDataRel());
 720
 721   XDataSection =
 722     Ctx->getCOFFSection(".xdata",
 723                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 724                         COFF::IMAGE_SCN_MEM_READ,
 725                         SectionKind::getDataRel());
 726   TLSDataSection =
 727     Ctx->getCOFFSection(".tls$",
 728                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 729                         COFF::IMAGE_SCN_MEM_READ |
 730                         COFF::IMAGE_SCN_MEM_WRITE,
 731                         SectionKind::getDataRel());
 732 }
 733
 734 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 735                                             CodeModel::Model cm,
 736                                             MCContext &ctx) {
 737   RelocM = relocm;
 738   CMModel = cm;
 739   Ctx = &ctx;
 740
 741   // Common.
 742   CommDirectiveSupportsAlignment = true;
 743   SupportsWeakOmittedEHFrame = true;
 744   IsFunctionEHFrameSymbolPrivate = true;
 745
 746   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
 747     TTypeEncoding = dwarf::DW_EH_PE_absptr;
 748
 749   CompactUnwindDwarfEHFrameOnly = 0;
 750
 751   EHFrameSection = 0;             // Created on demand.
 752   CompactUnwindSection = 0;       // Used only by selected targets.
 753   DwarfAccelNamesSection = 0;     // Used only by selected targets.
 754   DwarfAccelObjCSection = 0;      // Used only by selected targets.
 755   DwarfAccelNamespaceSection = 0; // Used only by selected targets.
 756   DwarfAccelTypesSection = 0;     // Used only by selected targets.
 757
 758   Triple T(TT);
 759   Triple::ArchType Arch = T.getArch();
 760   // FIXME: Checking for Arch here to filter out bogus triples such as
 761   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 762   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 763        Arch == Triple::arm || Arch == Triple::thumb ||
 764        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 765        Arch == Triple::UnknownArch) &&
 766       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 767     Env = IsMachO;
 768     InitMachOMCObjectFileInfo(T);
 769   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
 770              T.getObjectFormat() != Triple::ELF && T.isOSWindows()) {
 771     Env = IsCOFF;
 772     InitCOFFMCObjectFileInfo(T);
 773   } else {
 774     Env = IsELF;
 775     InitELFMCObjectFileInfo(T);
 776   }
 777 }
 778
 779 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 780   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 781                             SectionKind::getMetadata(), 0, utostr(Hash));
 782 }
 783
 784 const MCSection *
 785 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 786   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 787                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 788                             utostr(Hash));
 789 }
 790
 791 void MCObjectFileInfo::InitEHFrameSection() {
 792   if (Env == IsMachO)
 793     EHFrameSection =
 794       Ctx->getMachOSection("__TEXT", "__eh_frame",
 795                            MachO::S_COALESCED |
 796                            MachO::S_ATTR_NO_TOC |
 797                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 798                            MachO::S_ATTR_LIVE_SUPPORT,
 799                            SectionKind::getReadOnly());
 800   else if (Env == IsELF)
 801     EHFrameSection =
 802       Ctx->getELFSection(".eh_frame", EHSectionType,
 803                          EHSectionFlags,
 804                          SectionKind::getDataRel());
 805   else
 806     EHFrameSection =
 807       Ctx->getCOFFSection(".eh_frame",
 808                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 809                           COFF::IMAGE_SCN_MEM_READ |
 810                           COFF::IMAGE_SCN_MEM_WRITE,
 811                           SectionKind::getDataRel());
 812 }