lib/MC/MCObjectFileInfo.cpp

   1 //===-- MObjectFileInfo.cpp - Object File Information ---------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/MC/MCObjectFileInfo.h"
  11 #include "llvm/ADT/StringExtras.h"
  12 #include "llvm/ADT/Triple.h"
  13 #include "llvm/MC/MCAsmInfo.h"
  14 #include "llvm/MC/MCContext.h"
  15 #include "llvm/MC/MCSection.h"
  16 #include "llvm/MC/MCSectionCOFF.h"
  17 #include "llvm/MC/MCSectionELF.h"
  18 #include "llvm/MC/MCSectionMachO.h"
  19 using namespace llvm;
  20
  21 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
  22   // MachO
  23   IsFunctionEHFrameSymbolPrivate = false;
  24   SupportsWeakOmittedEHFrame = false;
  25
  26   if (T.isOSDarwin() && T.getArch() == Triple::arm64)
  27     SupportsCompactUnwindWithoutEHFrame = true;
  28
  29   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  30     | dwarf::DW_EH_PE_sdata4;
  31   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  32   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  33     dwarf::DW_EH_PE_sdata4;
  34
  35   // .comm doesn't support alignment before Leopard.
  36   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  37     CommDirectiveSupportsAlignment = false;
  38
  39   TextSection // .text
  40     = Ctx->getMachOSection("__TEXT", "__text",
  41                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  42                            SectionKind::getText());
  43   DataSection // .data
  44     = Ctx->getMachOSection("__DATA", "__data", 0,
  45                            SectionKind::getDataRel());
  46
  47   // BSSSection might not be expected initialized on msvc.
  48   BSSSection = nullptr;
  49
  50   TLSDataSection // .tdata
  51     = Ctx->getMachOSection("__DATA", "__thread_data",
  52                            MachO::S_THREAD_LOCAL_REGULAR,
  53                            SectionKind::getDataRel());
  54   TLSBSSSection // .tbss
  55     = Ctx->getMachOSection("__DATA", "__thread_bss",
  56                            MachO::S_THREAD_LOCAL_ZEROFILL,
  57                            SectionKind::getThreadBSS());
  58
  59   // TODO: Verify datarel below.
  60   TLSTLVSection // .tlv
  61     = Ctx->getMachOSection("__DATA", "__thread_vars",
  62                            MachO::S_THREAD_LOCAL_VARIABLES,
  63                            SectionKind::getDataRel());
  64
  65   TLSThreadInitSection
  66     = Ctx->getMachOSection("__DATA", "__thread_init",
  67                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  68                           SectionKind::getDataRel());
  69
  70   CStringSection // .cstring
  71     = Ctx->getMachOSection("__TEXT", "__cstring",
  72                            MachO::S_CSTRING_LITERALS,
  73                            SectionKind::getMergeable1ByteCString());
  74   UStringSection
  75     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  76                            SectionKind::getMergeable2ByteCString());
  77   FourByteConstantSection // .literal4
  78     = Ctx->getMachOSection("__TEXT", "__literal4",
  79                            MachO::S_4BYTE_LITERALS,
  80                            SectionKind::getMergeableConst4());
  81   EightByteConstantSection // .literal8
  82     = Ctx->getMachOSection("__TEXT", "__literal8",
  83                            MachO::S_8BYTE_LITERALS,
  84                            SectionKind::getMergeableConst8());
  85
  86   SixteenByteConstantSection // .literal16
  87       = Ctx->getMachOSection("__TEXT", "__literal16",
  88                              MachO::S_16BYTE_LITERALS,
  89                              SectionKind::getMergeableConst16());
  90
  91   ReadOnlySection  // .const
  92     = Ctx->getMachOSection("__TEXT", "__const", 0,
  93                            SectionKind::getReadOnly());
  94
  95   TextCoalSection
  96     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
  97                            MachO::S_COALESCED |
  98                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  99                            SectionKind::getText());
 100   ConstTextCoalSection
 101     = Ctx->getMachOSection("__TEXT", "__const_coal",
 102                            MachO::S_COALESCED,
 103                            SectionKind::getReadOnly());
 104   ConstDataSection  // .const_data
 105     = Ctx->getMachOSection("__DATA", "__const", 0,
 106                            SectionKind::getReadOnlyWithRel());
 107   DataCoalSection
 108     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 109                            MachO::S_COALESCED,
 110                            SectionKind::getDataRel());
 111   DataCommonSection
 112     = Ctx->getMachOSection("__DATA","__common",
 113                            MachO::S_ZEROFILL,
 114                            SectionKind::getBSS());
 115   DataBSSSection
 116     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 117                            SectionKind::getBSS());
 118
 119
 120   LazySymbolPointerSection
 121     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 122                            MachO::S_LAZY_SYMBOL_POINTERS,
 123                            SectionKind::getMetadata());
 124   NonLazySymbolPointerSection
 125     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 126                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 127                            SectionKind::getMetadata());
 128
 129   if (RelocM == Reloc::Static) {
 130     StaticCtorSection
 131       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 132                              SectionKind::getDataRel());
 133     StaticDtorSection
 134       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 135                              SectionKind::getDataRel());
 136   } else {
 137     StaticCtorSection
 138       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 139                              MachO::S_MOD_INIT_FUNC_POINTERS,
 140                              SectionKind::getDataRel());
 141     StaticDtorSection
 142       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 143                              MachO::S_MOD_TERM_FUNC_POINTERS,
 144                              SectionKind::getDataRel());
 145   }
 146
 147   // Exception Handling.
 148   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 149                                      SectionKind::getReadOnlyWithRel());
 150
 151   COFFDebugSymbolsSection = nullptr;
 152
 153   if ((T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) ||
 154       (T.isOSDarwin() && T.getArch() == Triple::arm64)) {
 155     CompactUnwindSection =
 156       Ctx->getMachOSection("__LD", "__compact_unwind",
 157                            MachO::S_ATTR_DEBUG,
 158                            SectionKind::getReadOnly());
 159
 160     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 161       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 162     else if (T.getArch() == Triple::arm64)
 163       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 164   }
 165
 166   // Debug Information.
 167   DwarfAccelNamesSection =
 168     Ctx->getMachOSection("__DWARF", "__apple_names",
 169                          MachO::S_ATTR_DEBUG,
 170                          SectionKind::getMetadata());
 171   DwarfAccelObjCSection =
 172     Ctx->getMachOSection("__DWARF", "__apple_objc",
 173                          MachO::S_ATTR_DEBUG,
 174                          SectionKind::getMetadata());
 175   // 16 character section limit...
 176   DwarfAccelNamespaceSection =
 177     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 178                          MachO::S_ATTR_DEBUG,
 179                          SectionKind::getMetadata());
 180   DwarfAccelTypesSection =
 181     Ctx->getMachOSection("__DWARF", "__apple_types",
 182                          MachO::S_ATTR_DEBUG,
 183                          SectionKind::getMetadata());
 184
 185   DwarfAbbrevSection =
 186     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 187                          MachO::S_ATTR_DEBUG,
 188                          SectionKind::getMetadata());
 189   DwarfInfoSection =
 190     Ctx->getMachOSection("__DWARF", "__debug_info",
 191                          MachO::S_ATTR_DEBUG,
 192                          SectionKind::getMetadata());
 193   DwarfLineSection =
 194     Ctx->getMachOSection("__DWARF", "__debug_line",
 195                          MachO::S_ATTR_DEBUG,
 196                          SectionKind::getMetadata());
 197   DwarfFrameSection =
 198     Ctx->getMachOSection("__DWARF", "__debug_frame",
 199                          MachO::S_ATTR_DEBUG,
 200                          SectionKind::getMetadata());
 201   DwarfPubNamesSection =
 202     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 203                          MachO::S_ATTR_DEBUG,
 204                          SectionKind::getMetadata());
 205   DwarfPubTypesSection =
 206     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 207                          MachO::S_ATTR_DEBUG,
 208                          SectionKind::getMetadata());
 209   DwarfGnuPubNamesSection =
 210     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 211                          MachO::S_ATTR_DEBUG,
 212                          SectionKind::getMetadata());
 213   DwarfGnuPubTypesSection =
 214     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 215                          MachO::S_ATTR_DEBUG,
 216                          SectionKind::getMetadata());
 217   DwarfStrSection =
 218     Ctx->getMachOSection("__DWARF", "__debug_str",
 219                          MachO::S_ATTR_DEBUG,
 220                          SectionKind::getMetadata());
 221   DwarfLocSection =
 222     Ctx->getMachOSection("__DWARF", "__debug_loc",
 223                          MachO::S_ATTR_DEBUG,
 224                          SectionKind::getMetadata());
 225   DwarfARangesSection =
 226     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 227                          MachO::S_ATTR_DEBUG,
 228                          SectionKind::getMetadata());
 229   DwarfRangesSection =
 230     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 231                          MachO::S_ATTR_DEBUG,
 232                          SectionKind::getMetadata());
 233   DwarfMacroInfoSection =
 234     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 235                          MachO::S_ATTR_DEBUG,
 236                          SectionKind::getMetadata());
 237   DwarfDebugInlineSection =
 238     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 239                          MachO::S_ATTR_DEBUG,
 240                          SectionKind::getMetadata());
 241   StackMapSection =
 242     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 243                          SectionKind::getMetadata());
 244
 245   TLSExtraDataSection = TLSTLVSection;
 246 }
 247
 248 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 249   switch (T.getArch()) {
 250   case Triple::mips:
 251   case Triple::mipsel:
 252     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 253     break;
 254   case Triple::mips64:
 255   case Triple::mips64el:
 256     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 257     break;
 258   default:
 259     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 260     break;
 261   }
 262
 263   switch (T.getArch()) {
 264   case Triple::arm:
 265   case Triple::armeb:
 266   case Triple::thumb:
 267   case Triple::thumbeb:
 268     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 269       break;
 270     // Fallthrough if not using EHABI
 271   case Triple::x86:
 272     PersonalityEncoding = (RelocM == Reloc::PIC_)
 273      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 274      : dwarf::DW_EH_PE_absptr;
 275     LSDAEncoding = (RelocM == Reloc::PIC_)
 276       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 277       : dwarf::DW_EH_PE_absptr;
 278     TTypeEncoding = (RelocM == Reloc::PIC_)
 279      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 280      : dwarf::DW_EH_PE_absptr;
 281     break;
 282   case Triple::x86_64:
 283     if (RelocM == Reloc::PIC_) {
 284       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 285         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 286          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 287       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 288         (CMModel == CodeModel::Small
 289          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 290       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 291         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 292          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 293     } else {
 294       PersonalityEncoding =
 295         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 296         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 297       LSDAEncoding = (CMModel == CodeModel::Small)
 298         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 299       TTypeEncoding = (CMModel == CodeModel::Small)
 300         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 301     }
 302     break;
 303   case Triple::aarch64:
 304   case Triple::aarch64_be:
 305   case Triple::arm64:
 306   case Triple::arm64_be:
 307     // The small model guarantees static code/data size < 4GB, but not where it
 308     // will be in memory. Most of these could end up >2GB away so even a signed
 309     // pc-relative 32-bit address is insufficient, theoretically.
 310     if (RelocM == Reloc::PIC_) {
 311       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 312         dwarf::DW_EH_PE_sdata8;
 313       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 314       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 315         dwarf::DW_EH_PE_sdata8;
 316     } else {
 317       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 318       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 319       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 320     }
 321     break;
 322   case Triple::ppc64:
 323   case Triple::ppc64le:
 324     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 325       dwarf::DW_EH_PE_udata8;
 326     LSDAEncoding = 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       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 336         dwarf::DW_EH_PE_sdata4;
 337     } else {
 338       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 339       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 340       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 341     }
 342     break;
 343   case Triple::sparcv9:
 344     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 345     if (RelocM == Reloc::PIC_) {
 346       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 347         dwarf::DW_EH_PE_sdata4;
 348       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 349         dwarf::DW_EH_PE_sdata4;
 350     } else {
 351       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 352       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 353     }
 354     break;
 355   case Triple::systemz:
 356     // All currently-defined code models guarantee that 4-byte PC-relative
 357     // values will be in range.
 358     if (RelocM == Reloc::PIC_) {
 359       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 360         dwarf::DW_EH_PE_sdata4;
 361       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 362       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 363         dwarf::DW_EH_PE_sdata4;
 364     } else {
 365       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 366       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 367       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 368     }
 369     break;
 370   default:
 371     break;
 372   }
 373
 374   // Solaris requires different flags for .eh_frame to seemingly every other
 375   // platform.
 376   EHSectionType = ELF::SHT_PROGBITS;
 377   EHSectionFlags = ELF::SHF_ALLOC;
 378   if (T.getOS() == Triple::Solaris) {
 379     if (T.getArch() == Triple::x86_64)
 380       EHSectionType = ELF::SHT_X86_64_UNWIND;
 381     else
 382       EHSectionFlags |= ELF::SHF_WRITE;
 383   }
 384
 385
 386   // ELF
 387   BSSSection =
 388     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 389                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 390                        SectionKind::getBSS());
 391
 392   TextSection =
 393     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 394                        ELF::SHF_EXECINSTR |
 395                        ELF::SHF_ALLOC,
 396                        SectionKind::getText());
 397
 398   DataSection =
 399     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 400                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 401                        SectionKind::getDataRel());
 402
 403   ReadOnlySection =
 404     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 405                        ELF::SHF_ALLOC,
 406                        SectionKind::getReadOnly());
 407
 408   TLSDataSection =
 409     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 410                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 411                        ELF::SHF_WRITE,
 412                        SectionKind::getThreadData());
 413
 414   TLSBSSSection =
 415     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 416                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 417                        ELF::SHF_WRITE,
 418                        SectionKind::getThreadBSS());
 419
 420   DataRelSection =
 421     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 422                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 423                        SectionKind::getDataRel());
 424
 425   DataRelLocalSection =
 426     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 427                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 428                        SectionKind::getDataRelLocal());
 429
 430   DataRelROSection =
 431     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 432                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 433                        SectionKind::getReadOnlyWithRel());
 434
 435   DataRelROLocalSection =
 436     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 437                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 438                        SectionKind::getReadOnlyWithRelLocal());
 439
 440   MergeableConst4Section =
 441     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 442                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 443                        SectionKind::getMergeableConst4());
 444
 445   MergeableConst8Section =
 446     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 447                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 448                        SectionKind::getMergeableConst8());
 449
 450   MergeableConst16Section =
 451     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 452                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 453                        SectionKind::getMergeableConst16());
 454
 455   StaticCtorSection =
 456     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 457                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 458                        SectionKind::getDataRel());
 459
 460   StaticDtorSection =
 461     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 462                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 463                        SectionKind::getDataRel());
 464
 465   // Exception Handling Sections.
 466
 467   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 468   // it contains relocatable pointers.  In PIC mode, this is probably a big
 469   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 470   // adjusted or this should be a data section.
 471   LSDASection =
 472     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 473                        ELF::SHF_ALLOC,
 474                        SectionKind::getReadOnly());
 475
 476   COFFDebugSymbolsSection = nullptr;
 477
 478   // Debug Info Sections.
 479   DwarfAbbrevSection =
 480     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 481                        SectionKind::getMetadata());
 482   DwarfInfoSection =
 483     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 484                        SectionKind::getMetadata());
 485   DwarfLineSection =
 486     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 487                        SectionKind::getMetadata());
 488   DwarfFrameSection =
 489     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 490                        SectionKind::getMetadata());
 491   DwarfPubNamesSection =
 492     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 493                        SectionKind::getMetadata());
 494   DwarfPubTypesSection =
 495     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 496                        SectionKind::getMetadata());
 497   DwarfGnuPubNamesSection =
 498     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 499                        SectionKind::getMetadata());
 500   DwarfGnuPubTypesSection =
 501     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 502                        SectionKind::getMetadata());
 503   DwarfStrSection =
 504     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 505                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 506                        SectionKind::getMergeable1ByteCString());
 507   DwarfLocSection =
 508     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 509                        SectionKind::getMetadata());
 510   DwarfARangesSection =
 511     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 512                        SectionKind::getMetadata());
 513   DwarfRangesSection =
 514     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 515                        SectionKind::getMetadata());
 516   DwarfMacroInfoSection =
 517     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 518                        SectionKind::getMetadata());
 519
 520   // DWARF5 Experimental Debug Info
 521
 522   // Accelerator Tables
 523   DwarfAccelNamesSection =
 524     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 525                        SectionKind::getMetadata());
 526   DwarfAccelObjCSection =
 527     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 528                        SectionKind::getMetadata());
 529   DwarfAccelNamespaceSection =
 530     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 531                        SectionKind::getMetadata());
 532   DwarfAccelTypesSection =
 533     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 534                        SectionKind::getMetadata());
 535
 536   // Fission Sections
 537   DwarfInfoDWOSection =
 538     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 539                        SectionKind::getMetadata());
 540   DwarfAbbrevDWOSection =
 541     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 542                        SectionKind::getMetadata());
 543   DwarfStrDWOSection =
 544     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 545                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 546                        SectionKind::getMergeable1ByteCString());
 547   DwarfLineDWOSection =
 548     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 549                        SectionKind::getMetadata());
 550   DwarfLocDWOSection =
 551     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 552                        SectionKind::getMetadata());
 553   DwarfStrOffDWOSection =
 554     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 555                        SectionKind::getMetadata());
 556   DwarfAddrSection =
 557     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 558                        SectionKind::getMetadata());
 559 }
 560
 561
 562 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 563   // The object file format cannot represent common symbols with explicit
 564   // alignments.
 565   CommDirectiveSupportsAlignment = false;
 566
 567   // COFF
 568   BSSSection =
 569     Ctx->getCOFFSection(".bss",
 570                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 571                         COFF::IMAGE_SCN_MEM_READ |
 572                         COFF::IMAGE_SCN_MEM_WRITE,
 573                         SectionKind::getBSS());
 574   TextSection =
 575     Ctx->getCOFFSection(".text",
 576                         COFF::IMAGE_SCN_CNT_CODE |
 577                         COFF::IMAGE_SCN_MEM_EXECUTE |
 578                         COFF::IMAGE_SCN_MEM_READ,
 579                         SectionKind::getText());
 580   DataSection =
 581     Ctx->getCOFFSection(".data",
 582                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 583                         COFF::IMAGE_SCN_MEM_READ |
 584                         COFF::IMAGE_SCN_MEM_WRITE,
 585                         SectionKind::getDataRel());
 586   ReadOnlySection =
 587     Ctx->getCOFFSection(".rdata",
 588                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 589                         COFF::IMAGE_SCN_MEM_READ,
 590                         SectionKind::getReadOnly());
 591   if (T.isKnownWindowsMSVCEnvironment()) {
 592     StaticCtorSection =
 593       Ctx->getCOFFSection(".CRT$XCU",
 594                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 595                           COFF::IMAGE_SCN_MEM_READ,
 596                           SectionKind::getReadOnly());
 597   } else {
 598     StaticCtorSection =
 599       Ctx->getCOFFSection(".ctors",
 600                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 601                           COFF::IMAGE_SCN_MEM_READ |
 602                           COFF::IMAGE_SCN_MEM_WRITE,
 603                           SectionKind::getDataRel());
 604   }
 605
 606
 607   if (T.isKnownWindowsMSVCEnvironment()) {
 608     StaticDtorSection =
 609       Ctx->getCOFFSection(".CRT$XTX",
 610                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 611                           COFF::IMAGE_SCN_MEM_READ,
 612                           SectionKind::getReadOnly());
 613   } else {
 614     StaticDtorSection =
 615       Ctx->getCOFFSection(".dtors",
 616                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 617                           COFF::IMAGE_SCN_MEM_READ |
 618                           COFF::IMAGE_SCN_MEM_WRITE,
 619                           SectionKind::getDataRel());
 620   }
 621
 622   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 623   // though it contains relocatable pointers.  In PIC mode, this is probably a
 624   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 625   // adjusted or this should be a data section.
 626   LSDASection =
 627     Ctx->getCOFFSection(".gcc_except_table",
 628                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 629                         COFF::IMAGE_SCN_MEM_READ,
 630                         SectionKind::getReadOnly());
 631
 632   // Debug info.
 633   COFFDebugSymbolsSection =
 634     Ctx->getCOFFSection(".debug$S",
 635                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 636                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 637                         COFF::IMAGE_SCN_MEM_READ,
 638                         SectionKind::getMetadata());
 639
 640   DwarfAbbrevSection =
 641     Ctx->getCOFFSection(".debug_abbrev",
 642                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 643                         COFF::IMAGE_SCN_MEM_READ,
 644                         SectionKind::getMetadata());
 645   DwarfInfoSection =
 646     Ctx->getCOFFSection(".debug_info",
 647                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 648                         COFF::IMAGE_SCN_MEM_READ,
 649                         SectionKind::getMetadata());
 650   DwarfLineSection =
 651     Ctx->getCOFFSection(".debug_line",
 652                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 653                         COFF::IMAGE_SCN_MEM_READ,
 654                         SectionKind::getMetadata());
 655   DwarfFrameSection =
 656     Ctx->getCOFFSection(".debug_frame",
 657                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 658                         COFF::IMAGE_SCN_MEM_READ,
 659                         SectionKind::getMetadata());
 660   DwarfPubNamesSection =
 661     Ctx->getCOFFSection(".debug_pubnames",
 662                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 663                         COFF::IMAGE_SCN_MEM_READ,
 664                         SectionKind::getMetadata());
 665   DwarfPubTypesSection =
 666     Ctx->getCOFFSection(".debug_pubtypes",
 667                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 668                         COFF::IMAGE_SCN_MEM_READ,
 669                         SectionKind::getMetadata());
 670   DwarfGnuPubNamesSection =
 671     Ctx->getCOFFSection(".debug_gnu_pubnames",
 672                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 673                         COFF::IMAGE_SCN_MEM_READ,
 674                         SectionKind::getMetadata());
 675   DwarfGnuPubTypesSection =
 676     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 677                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 678                         COFF::IMAGE_SCN_MEM_READ,
 679                         SectionKind::getMetadata());
 680   DwarfStrSection =
 681     Ctx->getCOFFSection(".debug_str",
 682                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 683                         COFF::IMAGE_SCN_MEM_READ,
 684                         SectionKind::getMetadata());
 685   DwarfLocSection =
 686     Ctx->getCOFFSection(".debug_loc",
 687                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 688                         COFF::IMAGE_SCN_MEM_READ,
 689                         SectionKind::getMetadata());
 690   DwarfARangesSection =
 691     Ctx->getCOFFSection(".debug_aranges",
 692                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 693                         COFF::IMAGE_SCN_MEM_READ,
 694                         SectionKind::getMetadata());
 695   DwarfRangesSection =
 696     Ctx->getCOFFSection(".debug_ranges",
 697                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 698                         COFF::IMAGE_SCN_MEM_READ,
 699                         SectionKind::getMetadata());
 700   DwarfMacroInfoSection =
 701     Ctx->getCOFFSection(".debug_macinfo",
 702                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 703                         COFF::IMAGE_SCN_MEM_READ,
 704                         SectionKind::getMetadata());
 705   DwarfInfoDWOSection =
 706       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 707                                                 COFF::IMAGE_SCN_MEM_READ,
 708                           SectionKind::getMetadata());
 709   DwarfAbbrevDWOSection =
 710       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 711                                                   COFF::IMAGE_SCN_MEM_READ,
 712                           SectionKind::getMetadata());
 713   DwarfStrDWOSection =
 714       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 715                                                COFF::IMAGE_SCN_MEM_READ,
 716                           SectionKind::getMetadata());
 717   DwarfLineDWOSection =
 718       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 719                                                 COFF::IMAGE_SCN_MEM_READ,
 720                           SectionKind::getMetadata());
 721   DwarfLocDWOSection =
 722       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 723                                                COFF::IMAGE_SCN_MEM_READ,
 724                           SectionKind::getMetadata());
 725   DwarfStrOffDWOSection =
 726       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 727                                                   COFF::IMAGE_SCN_MEM_READ,
 728                           SectionKind::getMetadata());
 729   DwarfAddrSection = Ctx->getCOFFSection(
 730       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 731       SectionKind::getMetadata());
 732
 733   DrectveSection =
 734     Ctx->getCOFFSection(".drectve",
 735                         COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 736                         SectionKind::getMetadata());
 737
 738   PDataSection =
 739     Ctx->getCOFFSection(".pdata",
 740                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 741                         COFF::IMAGE_SCN_MEM_READ,
 742                         SectionKind::getDataRel());
 743
 744   XDataSection =
 745     Ctx->getCOFFSection(".xdata",
 746                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 747                         COFF::IMAGE_SCN_MEM_READ,
 748                         SectionKind::getDataRel());
 749   TLSDataSection =
 750     Ctx->getCOFFSection(".tls$",
 751                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 752                         COFF::IMAGE_SCN_MEM_READ |
 753                         COFF::IMAGE_SCN_MEM_WRITE,
 754                         SectionKind::getDataRel());
 755 }
 756
 757 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 758                                             CodeModel::Model cm,
 759                                             MCContext &ctx) {
 760   RelocM = relocm;
 761   CMModel = cm;
 762   Ctx = &ctx;
 763
 764   // Common.
 765   CommDirectiveSupportsAlignment = true;
 766   SupportsWeakOmittedEHFrame = true;
 767   IsFunctionEHFrameSymbolPrivate = true;
 768   SupportsCompactUnwindWithoutEHFrame = false;
 769
 770   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 771       dwarf::DW_EH_PE_absptr;
 772
 773   CompactUnwindDwarfEHFrameOnly = 0;
 774
 775   EHFrameSection = nullptr;             // Created on demand.
 776   CompactUnwindSection = nullptr;       // Used only by selected targets.
 777   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 778   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 779   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 780   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 781
 782   Triple T(TT);
 783   Triple::ArchType Arch = T.getArch();
 784   // FIXME: Checking for Arch here to filter out bogus triples such as
 785   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 786   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 787        Arch == Triple::arm || Arch == Triple::thumb ||
 788        Arch == Triple::arm64 ||
 789        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 790        Arch == Triple::UnknownArch) &&
 791       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 792     Env = IsMachO;
 793     InitMachOMCObjectFileInfo(T);
 794   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 795               Arch == Triple::arm || Arch == Triple::thumb) &&
 796              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 797     Env = IsCOFF;
 798     InitCOFFMCObjectFileInfo(T);
 799   } else {
 800     Env = IsELF;
 801     InitELFMCObjectFileInfo(T);
 802   }
 803 }
 804
 805 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 806   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 807                             SectionKind::getMetadata(), 0, utostr(Hash));
 808 }
 809
 810 const MCSection *
 811 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 812   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 813                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 814                             utostr(Hash));
 815 }
 816
 817 void MCObjectFileInfo::InitEHFrameSection() {
 818   if (Env == IsMachO)
 819     EHFrameSection =
 820       Ctx->getMachOSection("__TEXT", "__eh_frame",
 821                            MachO::S_COALESCED |
 822                            MachO::S_ATTR_NO_TOC |
 823                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 824                            MachO::S_ATTR_LIVE_SUPPORT,
 825                            SectionKind::getReadOnly());
 826   else if (Env == IsELF)
 827     EHFrameSection =
 828       Ctx->getELFSection(".eh_frame", EHSectionType,
 829                          EHSectionFlags,
 830                          SectionKind::getDataRel());
 831   else
 832     EHFrameSection =
 833       Ctx->getCOFFSection(".eh_frame",
 834                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 835                           COFF::IMAGE_SCN_MEM_READ |
 836                           COFF::IMAGE_SCN_MEM_WRITE,
 837                           SectionKind::getDataRel());
 838 }