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::arm:
 264   case Triple::armeb:
 265   case Triple::thumb:
 266   case Triple::thumbeb:
 267   case Triple::x86:
 268     PersonalityEncoding = (RelocM == Reloc::PIC_)
 269      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 270      : dwarf::DW_EH_PE_absptr;
 271     LSDAEncoding = (RelocM == Reloc::PIC_)
 272       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 273       : dwarf::DW_EH_PE_absptr;
 274     FDEEncoding = (RelocM == Reloc::PIC_)
 275       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 276       : dwarf::DW_EH_PE_absptr;
 277     TTypeEncoding = (RelocM == Reloc::PIC_)
 278      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 279      : dwarf::DW_EH_PE_absptr;
 280     break;
 281   case Triple::x86_64:
 282     if (RelocM == Reloc::PIC_) {
 283       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 284         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 285          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 286       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 287         (CMModel == CodeModel::Small
 288          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 289       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 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       FDEEncoding = dwarf::DW_EH_PE_udata4;
 300       TTypeEncoding = (CMModel == CodeModel::Small)
 301         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 302     }
 303     break;
 304   case Triple::aarch64:
 305   case Triple::aarch64_be:
 306   case Triple::arm64:
 307   case Triple::arm64_be:
 308     // The small model guarantees static code/data size < 4GB, but not where it
 309     // will be in memory. Most of these could end up >2GB away so even a signed
 310     // pc-relative 32-bit address is insufficient, theoretically.
 311     if (RelocM == Reloc::PIC_) {
 312       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 313         dwarf::DW_EH_PE_sdata8;
 314       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 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_sdata8;
 318     } else {
 319       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 320       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 321       FDEEncoding = dwarf::DW_EH_PE_udata4;
 322       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 323     }
 324     break;
 325   case Triple::ppc64:
 326   case Triple::ppc64le:
 327     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 328       dwarf::DW_EH_PE_udata8;
 329     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 330     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 331     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 332       dwarf::DW_EH_PE_udata8;
 333     break;
 334   case Triple::sparc:
 335     if (RelocM == Reloc::PIC_) {
 336       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 337       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 338         dwarf::DW_EH_PE_sdata4;
 339       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 340       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 341         dwarf::DW_EH_PE_sdata4;
 342     } else {
 343       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 344       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 345       FDEEncoding = dwarf::DW_EH_PE_udata4;
 346       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 347     }
 348     break;
 349   case Triple::sparcv9:
 350     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 351     if (RelocM == Reloc::PIC_) {
 352       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 353         dwarf::DW_EH_PE_sdata4;
 354       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 355       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 356         dwarf::DW_EH_PE_sdata4;
 357     } else {
 358       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 359       FDEEncoding = dwarf::DW_EH_PE_udata4;
 360       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 361     }
 362     break;
 363   case Triple::systemz:
 364     // All currently-defined code models guarantee that 4-byte PC-relative
 365     // values will be in range.
 366     if (RelocM == Reloc::PIC_) {
 367       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 368         dwarf::DW_EH_PE_sdata4;
 369       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 370       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 371       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 372         dwarf::DW_EH_PE_sdata4;
 373     } else {
 374       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 375       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 376       FDEEncoding = dwarf::DW_EH_PE_absptr;
 377       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 378     }
 379     break;
 380   default:
 381     break;
 382   }
 383
 384   // Solaris requires different flags for .eh_frame to seemingly every other
 385   // platform.
 386   EHSectionType = ELF::SHT_PROGBITS;
 387   EHSectionFlags = ELF::SHF_ALLOC;
 388   if (T.getOS() == Triple::Solaris) {
 389     if (T.getArch() == Triple::x86_64)
 390       EHSectionType = ELF::SHT_X86_64_UNWIND;
 391     else
 392       EHSectionFlags |= ELF::SHF_WRITE;
 393   }
 394
 395
 396   // ELF
 397   BSSSection =
 398     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 399                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 400                        SectionKind::getBSS());
 401
 402   TextSection =
 403     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 404                        ELF::SHF_EXECINSTR |
 405                        ELF::SHF_ALLOC,
 406                        SectionKind::getText());
 407
 408   DataSection =
 409     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 410                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 411                        SectionKind::getDataRel());
 412
 413   ReadOnlySection =
 414     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 415                        ELF::SHF_ALLOC,
 416                        SectionKind::getReadOnly());
 417
 418   TLSDataSection =
 419     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 420                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 421                        ELF::SHF_WRITE,
 422                        SectionKind::getThreadData());
 423
 424   TLSBSSSection =
 425     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 426                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 427                        ELF::SHF_WRITE,
 428                        SectionKind::getThreadBSS());
 429
 430   DataRelSection =
 431     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 432                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 433                        SectionKind::getDataRel());
 434
 435   DataRelLocalSection =
 436     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 437                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 438                        SectionKind::getDataRelLocal());
 439
 440   DataRelROSection =
 441     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 442                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 443                        SectionKind::getReadOnlyWithRel());
 444
 445   DataRelROLocalSection =
 446     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 447                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 448                        SectionKind::getReadOnlyWithRelLocal());
 449
 450   MergeableConst4Section =
 451     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 452                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 453                        SectionKind::getMergeableConst4());
 454
 455   MergeableConst8Section =
 456     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 457                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 458                        SectionKind::getMergeableConst8());
 459
 460   MergeableConst16Section =
 461     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 462                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 463                        SectionKind::getMergeableConst16());
 464
 465   StaticCtorSection =
 466     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 467                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 468                        SectionKind::getDataRel());
 469
 470   StaticDtorSection =
 471     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 472                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 473                        SectionKind::getDataRel());
 474
 475   // Exception Handling Sections.
 476
 477   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 478   // it contains relocatable pointers.  In PIC mode, this is probably a big
 479   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 480   // adjusted or this should be a data section.
 481   LSDASection =
 482     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 483                        ELF::SHF_ALLOC,
 484                        SectionKind::getReadOnly());
 485
 486   COFFDebugSymbolsSection = nullptr;
 487
 488   // Debug Info Sections.
 489   DwarfAbbrevSection =
 490     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 491                        SectionKind::getMetadata());
 492   DwarfInfoSection =
 493     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 494                        SectionKind::getMetadata());
 495   DwarfLineSection =
 496     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 497                        SectionKind::getMetadata());
 498   DwarfFrameSection =
 499     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 500                        SectionKind::getMetadata());
 501   DwarfPubNamesSection =
 502     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 503                        SectionKind::getMetadata());
 504   DwarfPubTypesSection =
 505     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 506                        SectionKind::getMetadata());
 507   DwarfGnuPubNamesSection =
 508     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 509                        SectionKind::getMetadata());
 510   DwarfGnuPubTypesSection =
 511     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 512                        SectionKind::getMetadata());
 513   DwarfStrSection =
 514     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 515                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 516                        SectionKind::getMergeable1ByteCString());
 517   DwarfLocSection =
 518     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 519                        SectionKind::getMetadata());
 520   DwarfARangesSection =
 521     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 522                        SectionKind::getMetadata());
 523   DwarfRangesSection =
 524     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 525                        SectionKind::getMetadata());
 526   DwarfMacroInfoSection =
 527     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 528                        SectionKind::getMetadata());
 529
 530   // DWARF5 Experimental Debug Info
 531
 532   // Accelerator Tables
 533   DwarfAccelNamesSection =
 534     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 535                        SectionKind::getMetadata());
 536   DwarfAccelObjCSection =
 537     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 538                        SectionKind::getMetadata());
 539   DwarfAccelNamespaceSection =
 540     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 541                        SectionKind::getMetadata());
 542   DwarfAccelTypesSection =
 543     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 544                        SectionKind::getMetadata());
 545
 546   // Fission Sections
 547   DwarfInfoDWOSection =
 548     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 549                        SectionKind::getMetadata());
 550   DwarfAbbrevDWOSection =
 551     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 552                        SectionKind::getMetadata());
 553   DwarfStrDWOSection =
 554     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 555                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 556                        SectionKind::getMergeable1ByteCString());
 557   DwarfLineDWOSection =
 558     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 559                        SectionKind::getMetadata());
 560   DwarfLocDWOSection =
 561     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 562                        SectionKind::getMetadata());
 563   DwarfStrOffDWOSection =
 564     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 565                        SectionKind::getMetadata());
 566   DwarfAddrSection =
 567     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 568                        SectionKind::getMetadata());
 569 }
 570
 571
 572 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 573   // The object file format cannot represent common symbols with explicit
 574   // alignments.
 575   CommDirectiveSupportsAlignment = false;
 576
 577   // COFF
 578   BSSSection =
 579     Ctx->getCOFFSection(".bss",
 580                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 581                         COFF::IMAGE_SCN_MEM_READ |
 582                         COFF::IMAGE_SCN_MEM_WRITE,
 583                         SectionKind::getBSS());
 584   TextSection =
 585     Ctx->getCOFFSection(".text",
 586                         COFF::IMAGE_SCN_CNT_CODE |
 587                         COFF::IMAGE_SCN_MEM_EXECUTE |
 588                         COFF::IMAGE_SCN_MEM_READ,
 589                         SectionKind::getText());
 590   DataSection =
 591     Ctx->getCOFFSection(".data",
 592                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 593                         COFF::IMAGE_SCN_MEM_READ |
 594                         COFF::IMAGE_SCN_MEM_WRITE,
 595                         SectionKind::getDataRel());
 596   ReadOnlySection =
 597     Ctx->getCOFFSection(".rdata",
 598                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 599                         COFF::IMAGE_SCN_MEM_READ,
 600                         SectionKind::getReadOnly());
 601   if (T.isKnownWindowsMSVCEnvironment()) {
 602     StaticCtorSection =
 603       Ctx->getCOFFSection(".CRT$XCU",
 604                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 605                           COFF::IMAGE_SCN_MEM_READ,
 606                           SectionKind::getReadOnly());
 607   } else {
 608     StaticCtorSection =
 609       Ctx->getCOFFSection(".ctors",
 610                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 611                           COFF::IMAGE_SCN_MEM_READ |
 612                           COFF::IMAGE_SCN_MEM_WRITE,
 613                           SectionKind::getDataRel());
 614   }
 615
 616
 617   if (T.isKnownWindowsMSVCEnvironment()) {
 618     StaticDtorSection =
 619       Ctx->getCOFFSection(".CRT$XTX",
 620                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 621                           COFF::IMAGE_SCN_MEM_READ,
 622                           SectionKind::getReadOnly());
 623   } else {
 624     StaticDtorSection =
 625       Ctx->getCOFFSection(".dtors",
 626                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 627                           COFF::IMAGE_SCN_MEM_READ |
 628                           COFF::IMAGE_SCN_MEM_WRITE,
 629                           SectionKind::getDataRel());
 630   }
 631
 632   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 633   // though it contains relocatable pointers.  In PIC mode, this is probably a
 634   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 635   // adjusted or this should be a data section.
 636   LSDASection =
 637     Ctx->getCOFFSection(".gcc_except_table",
 638                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 639                         COFF::IMAGE_SCN_MEM_READ,
 640                         SectionKind::getReadOnly());
 641
 642   // Debug info.
 643   COFFDebugSymbolsSection =
 644     Ctx->getCOFFSection(".debug$S",
 645                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 646                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 647                         COFF::IMAGE_SCN_MEM_READ,
 648                         SectionKind::getMetadata());
 649
 650   DwarfAbbrevSection =
 651     Ctx->getCOFFSection(".debug_abbrev",
 652                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 653                         COFF::IMAGE_SCN_MEM_READ,
 654                         SectionKind::getMetadata());
 655   DwarfInfoSection =
 656     Ctx->getCOFFSection(".debug_info",
 657                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 658                         COFF::IMAGE_SCN_MEM_READ,
 659                         SectionKind::getMetadata());
 660   DwarfLineSection =
 661     Ctx->getCOFFSection(".debug_line",
 662                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 663                         COFF::IMAGE_SCN_MEM_READ,
 664                         SectionKind::getMetadata());
 665   DwarfFrameSection =
 666     Ctx->getCOFFSection(".debug_frame",
 667                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 668                         COFF::IMAGE_SCN_MEM_READ,
 669                         SectionKind::getMetadata());
 670   DwarfPubNamesSection =
 671     Ctx->getCOFFSection(".debug_pubnames",
 672                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 673                         COFF::IMAGE_SCN_MEM_READ,
 674                         SectionKind::getMetadata());
 675   DwarfPubTypesSection =
 676     Ctx->getCOFFSection(".debug_pubtypes",
 677                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 678                         COFF::IMAGE_SCN_MEM_READ,
 679                         SectionKind::getMetadata());
 680   DwarfGnuPubNamesSection =
 681     Ctx->getCOFFSection(".debug_gnu_pubnames",
 682                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 683                         COFF::IMAGE_SCN_MEM_READ,
 684                         SectionKind::getMetadata());
 685   DwarfGnuPubTypesSection =
 686     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 687                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 688                         COFF::IMAGE_SCN_MEM_READ,
 689                         SectionKind::getMetadata());
 690   DwarfStrSection =
 691     Ctx->getCOFFSection(".debug_str",
 692                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 693                         COFF::IMAGE_SCN_MEM_READ,
 694                         SectionKind::getMetadata());
 695   DwarfLocSection =
 696     Ctx->getCOFFSection(".debug_loc",
 697                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 698                         COFF::IMAGE_SCN_MEM_READ,
 699                         SectionKind::getMetadata());
 700   DwarfARangesSection =
 701     Ctx->getCOFFSection(".debug_aranges",
 702                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 703                         COFF::IMAGE_SCN_MEM_READ,
 704                         SectionKind::getMetadata());
 705   DwarfRangesSection =
 706     Ctx->getCOFFSection(".debug_ranges",
 707                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 708                         COFF::IMAGE_SCN_MEM_READ,
 709                         SectionKind::getMetadata());
 710   DwarfMacroInfoSection =
 711     Ctx->getCOFFSection(".debug_macinfo",
 712                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 713                         COFF::IMAGE_SCN_MEM_READ,
 714                         SectionKind::getMetadata());
 715   DwarfInfoDWOSection =
 716       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 717                                                 COFF::IMAGE_SCN_MEM_READ,
 718                           SectionKind::getMetadata());
 719   DwarfAbbrevDWOSection =
 720       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 721                                                   COFF::IMAGE_SCN_MEM_READ,
 722                           SectionKind::getMetadata());
 723   DwarfStrDWOSection =
 724       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 725                                                COFF::IMAGE_SCN_MEM_READ,
 726                           SectionKind::getMetadata());
 727   DwarfLineDWOSection =
 728       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 729                                                 COFF::IMAGE_SCN_MEM_READ,
 730                           SectionKind::getMetadata());
 731   DwarfLocDWOSection =
 732       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 733                                                COFF::IMAGE_SCN_MEM_READ,
 734                           SectionKind::getMetadata());
 735   DwarfStrOffDWOSection =
 736       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 737                                                   COFF::IMAGE_SCN_MEM_READ,
 738                           SectionKind::getMetadata());
 739   DwarfAddrSection = Ctx->getCOFFSection(
 740       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 741       SectionKind::getMetadata());
 742
 743   DrectveSection =
 744     Ctx->getCOFFSection(".drectve",
 745                         COFF::IMAGE_SCN_LNK_INFO,
 746                         SectionKind::getMetadata());
 747
 748   PDataSection =
 749     Ctx->getCOFFSection(".pdata",
 750                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 751                         COFF::IMAGE_SCN_MEM_READ,
 752                         SectionKind::getDataRel());
 753
 754   XDataSection =
 755     Ctx->getCOFFSection(".xdata",
 756                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 757                         COFF::IMAGE_SCN_MEM_READ,
 758                         SectionKind::getDataRel());
 759   TLSDataSection =
 760     Ctx->getCOFFSection(".tls$",
 761                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 762                         COFF::IMAGE_SCN_MEM_READ |
 763                         COFF::IMAGE_SCN_MEM_WRITE,
 764                         SectionKind::getDataRel());
 765 }
 766
 767 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 768                                             CodeModel::Model cm,
 769                                             MCContext &ctx) {
 770   RelocM = relocm;
 771   CMModel = cm;
 772   Ctx = &ctx;
 773
 774   // Common.
 775   CommDirectiveSupportsAlignment = true;
 776   SupportsWeakOmittedEHFrame = true;
 777   IsFunctionEHFrameSymbolPrivate = true;
 778   SupportsCompactUnwindWithoutEHFrame = false;
 779
 780   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
 781     TTypeEncoding = dwarf::DW_EH_PE_absptr;
 782
 783   CompactUnwindDwarfEHFrameOnly = 0;
 784
 785   EHFrameSection = nullptr;             // Created on demand.
 786   CompactUnwindSection = nullptr;       // Used only by selected targets.
 787   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 788   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 789   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 790   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 791
 792   Triple T(TT);
 793   Triple::ArchType Arch = T.getArch();
 794   // FIXME: Checking for Arch here to filter out bogus triples such as
 795   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 796   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 797        Arch == Triple::arm || Arch == Triple::thumb ||
 798        Arch == Triple::arm64 ||
 799        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 800        Arch == Triple::UnknownArch) &&
 801       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 802     Env = IsMachO;
 803     InitMachOMCObjectFileInfo(T);
 804   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 805               Arch == Triple::arm || Arch == Triple::thumb) &&
 806              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 807     Env = IsCOFF;
 808     InitCOFFMCObjectFileInfo(T);
 809   } else {
 810     Env = IsELF;
 811     InitELFMCObjectFileInfo(T);
 812   }
 813 }
 814
 815 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 816   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 817                             SectionKind::getMetadata(), 0, utostr(Hash));
 818 }
 819
 820 const MCSection *
 821 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 822   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 823                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 824                             utostr(Hash));
 825 }
 826
 827 void MCObjectFileInfo::InitEHFrameSection() {
 828   if (Env == IsMachO)
 829     EHFrameSection =
 830       Ctx->getMachOSection("__TEXT", "__eh_frame",
 831                            MachO::S_COALESCED |
 832                            MachO::S_ATTR_NO_TOC |
 833                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 834                            MachO::S_ATTR_LIVE_SUPPORT,
 835                            SectionKind::getReadOnly());
 836   else if (Env == IsELF)
 837     EHFrameSection =
 838       Ctx->getELFSection(".eh_frame", EHSectionType,
 839                          EHSectionFlags,
 840                          SectionKind::getDataRel());
 841   else
 842     EHFrameSection =
 843       Ctx->getCOFFSection(".eh_frame",
 844                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 845                           COFF::IMAGE_SCN_MEM_READ |
 846                           COFF::IMAGE_SCN_MEM_WRITE,
 847                           SectionKind::getDataRel());
 848 }