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   if (T.getArch() == Triple::mips ||
 249       T.getArch() == Triple::mipsel)
 250     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 251   else if (T.getArch() == Triple::mips64 ||
 252            T.getArch() == Triple::mips64el)
 253     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 254   else
 255     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 256
 257   if (T.getArch() == Triple::x86) {
 258     PersonalityEncoding = (RelocM == Reloc::PIC_)
 259      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 260      : dwarf::DW_EH_PE_absptr;
 261     LSDAEncoding = (RelocM == Reloc::PIC_)
 262       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 263       : dwarf::DW_EH_PE_absptr;
 264     FDEEncoding = (RelocM == Reloc::PIC_)
 265       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 266       : dwarf::DW_EH_PE_absptr;
 267     TTypeEncoding = (RelocM == Reloc::PIC_)
 268      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 269      : dwarf::DW_EH_PE_absptr;
 270   } else if (T.getArch() == Triple::x86_64) {
 271     if (RelocM == Reloc::PIC_) {
 272       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 273         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 274          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 275       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 276         (CMModel == CodeModel::Small
 277          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 278       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 279       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 280         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 281          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 282     } else {
 283       PersonalityEncoding =
 284         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 285         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 286       LSDAEncoding = (CMModel == CodeModel::Small)
 287         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 288       FDEEncoding = dwarf::DW_EH_PE_udata4;
 289       TTypeEncoding = (CMModel == CodeModel::Small)
 290         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 291     }
 292   } else if (T.getArch() == Triple::aarch64 ||
 293              T.getArch() == Triple::aarch64_be ||
 294              T.getArch() == Triple::arm64) {
 295     // The small model guarantees static code/data size < 4GB, but not where it
 296     // will be in memory. Most of these could end up >2GB away so even a signed
 297     // pc-relative 32-bit address is insufficient, theoretically.
 298     if (RelocM == Reloc::PIC_) {
 299       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 300         dwarf::DW_EH_PE_sdata8;
 301       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 302       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 303       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 304         dwarf::DW_EH_PE_sdata8;
 305     } else {
 306       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 307       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 308       FDEEncoding = dwarf::DW_EH_PE_udata4;
 309       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 310     }
 311   } else if (T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le) {
 312     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 313       dwarf::DW_EH_PE_udata8;
 314     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 315     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 316     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 317       dwarf::DW_EH_PE_udata8;
 318   } else if (T.getArch() == Triple::sparc) {
 319     if (RelocM == Reloc::PIC_) {
 320       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 321       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 322         dwarf::DW_EH_PE_sdata4;
 323       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 324       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 325         dwarf::DW_EH_PE_sdata4;
 326     } else {
 327       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 328       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 329       FDEEncoding = dwarf::DW_EH_PE_udata4;
 330       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 331     }
 332   } else if (T.getArch() == Triple::sparcv9) {
 333     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 334     if (RelocM == Reloc::PIC_) {
 335       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 336         dwarf::DW_EH_PE_sdata4;
 337       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 338       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 339         dwarf::DW_EH_PE_sdata4;
 340     } else {
 341       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 342       FDEEncoding = dwarf::DW_EH_PE_udata4;
 343       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 344     }
 345   } else if (T.getArch() == Triple::systemz) {
 346     // All currently-defined code models guarantee that 4-byte PC-relative
 347     // values will be in range.
 348     if (RelocM == Reloc::PIC_) {
 349       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 350         dwarf::DW_EH_PE_sdata4;
 351       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 352       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 353       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 354         dwarf::DW_EH_PE_sdata4;
 355     } else {
 356       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 357       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 358       FDEEncoding = dwarf::DW_EH_PE_absptr;
 359       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 360     }
 361   }
 362
 363   // Solaris requires different flags for .eh_frame to seemingly every other
 364   // platform.
 365   EHSectionType = ELF::SHT_PROGBITS;
 366   EHSectionFlags = ELF::SHF_ALLOC;
 367   if (T.getOS() == Triple::Solaris) {
 368     if (T.getArch() == Triple::x86_64)
 369       EHSectionType = ELF::SHT_X86_64_UNWIND;
 370     else
 371       EHSectionFlags |= ELF::SHF_WRITE;
 372   }
 373
 374
 375   // ELF
 376   BSSSection =
 377     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 378                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 379                        SectionKind::getBSS());
 380
 381   TextSection =
 382     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 383                        ELF::SHF_EXECINSTR |
 384                        ELF::SHF_ALLOC,
 385                        SectionKind::getText());
 386
 387   DataSection =
 388     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 389                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 390                        SectionKind::getDataRel());
 391
 392   ReadOnlySection =
 393     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 394                        ELF::SHF_ALLOC,
 395                        SectionKind::getReadOnly());
 396
 397   TLSDataSection =
 398     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 399                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 400                        ELF::SHF_WRITE,
 401                        SectionKind::getThreadData());
 402
 403   TLSBSSSection =
 404     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 405                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 406                        ELF::SHF_WRITE,
 407                        SectionKind::getThreadBSS());
 408
 409   DataRelSection =
 410     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 411                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 412                        SectionKind::getDataRel());
 413
 414   DataRelLocalSection =
 415     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 416                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 417                        SectionKind::getDataRelLocal());
 418
 419   DataRelROSection =
 420     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 421                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 422                        SectionKind::getReadOnlyWithRel());
 423
 424   DataRelROLocalSection =
 425     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 426                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 427                        SectionKind::getReadOnlyWithRelLocal());
 428
 429   MergeableConst4Section =
 430     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 431                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 432                        SectionKind::getMergeableConst4());
 433
 434   MergeableConst8Section =
 435     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 436                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 437                        SectionKind::getMergeableConst8());
 438
 439   MergeableConst16Section =
 440     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 441                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 442                        SectionKind::getMergeableConst16());
 443
 444   StaticCtorSection =
 445     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 446                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 447                        SectionKind::getDataRel());
 448
 449   StaticDtorSection =
 450     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 451                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 452                        SectionKind::getDataRel());
 453
 454   // Exception Handling Sections.
 455
 456   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 457   // it contains relocatable pointers.  In PIC mode, this is probably a big
 458   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 459   // adjusted or this should be a data section.
 460   LSDASection =
 461     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 462                        ELF::SHF_ALLOC,
 463                        SectionKind::getReadOnly());
 464
 465   COFFDebugSymbolsSection = nullptr;
 466
 467   // Debug Info Sections.
 468   DwarfAbbrevSection =
 469     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 470                        SectionKind::getMetadata());
 471   DwarfInfoSection =
 472     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 473                        SectionKind::getMetadata());
 474   DwarfLineSection =
 475     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 476                        SectionKind::getMetadata());
 477   DwarfFrameSection =
 478     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 479                        SectionKind::getMetadata());
 480   DwarfPubNamesSection =
 481     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 482                        SectionKind::getMetadata());
 483   DwarfPubTypesSection =
 484     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 485                        SectionKind::getMetadata());
 486   DwarfGnuPubNamesSection =
 487     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 488                        SectionKind::getMetadata());
 489   DwarfGnuPubTypesSection =
 490     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 491                        SectionKind::getMetadata());
 492   DwarfStrSection =
 493     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 494                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 495                        SectionKind::getMergeable1ByteCString());
 496   DwarfLocSection =
 497     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 498                        SectionKind::getMetadata());
 499   DwarfARangesSection =
 500     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 501                        SectionKind::getMetadata());
 502   DwarfRangesSection =
 503     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 504                        SectionKind::getMetadata());
 505   DwarfMacroInfoSection =
 506     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 507                        SectionKind::getMetadata());
 508
 509   // DWARF5 Experimental Debug Info
 510
 511   // Accelerator Tables
 512   DwarfAccelNamesSection =
 513     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 514                        SectionKind::getMetadata());
 515   DwarfAccelObjCSection =
 516     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 517                        SectionKind::getMetadata());
 518   DwarfAccelNamespaceSection =
 519     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 520                        SectionKind::getMetadata());
 521   DwarfAccelTypesSection =
 522     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 523                        SectionKind::getMetadata());
 524
 525   // Fission Sections
 526   DwarfInfoDWOSection =
 527     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 528                        SectionKind::getMetadata());
 529   DwarfAbbrevDWOSection =
 530     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 531                        SectionKind::getMetadata());
 532   DwarfStrDWOSection =
 533     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 534                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 535                        SectionKind::getMergeable1ByteCString());
 536   DwarfLineDWOSection =
 537     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 538                        SectionKind::getMetadata());
 539   DwarfLocDWOSection =
 540     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 541                        SectionKind::getMetadata());
 542   DwarfStrOffDWOSection =
 543     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 544                        SectionKind::getMetadata());
 545   DwarfAddrSection =
 546     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 547                        SectionKind::getMetadata());
 548 }
 549
 550
 551 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 552   // The object file format cannot represent common symbols with explicit
 553   // alignments.
 554   CommDirectiveSupportsAlignment = false;
 555
 556   // COFF
 557   BSSSection =
 558     Ctx->getCOFFSection(".bss",
 559                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 560                         COFF::IMAGE_SCN_MEM_READ |
 561                         COFF::IMAGE_SCN_MEM_WRITE,
 562                         SectionKind::getBSS());
 563   TextSection =
 564     Ctx->getCOFFSection(".text",
 565                         COFF::IMAGE_SCN_CNT_CODE |
 566                         COFF::IMAGE_SCN_MEM_EXECUTE |
 567                         COFF::IMAGE_SCN_MEM_READ,
 568                         SectionKind::getText());
 569   DataSection =
 570     Ctx->getCOFFSection(".data",
 571                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 572                         COFF::IMAGE_SCN_MEM_READ |
 573                         COFF::IMAGE_SCN_MEM_WRITE,
 574                         SectionKind::getDataRel());
 575   ReadOnlySection =
 576     Ctx->getCOFFSection(".rdata",
 577                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 578                         COFF::IMAGE_SCN_MEM_READ,
 579                         SectionKind::getReadOnly());
 580   if (T.isKnownWindowsMSVCEnvironment()) {
 581     StaticCtorSection =
 582       Ctx->getCOFFSection(".CRT$XCU",
 583                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 584                           COFF::IMAGE_SCN_MEM_READ,
 585                           SectionKind::getReadOnly());
 586   } else {
 587     StaticCtorSection =
 588       Ctx->getCOFFSection(".ctors",
 589                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 590                           COFF::IMAGE_SCN_MEM_READ |
 591                           COFF::IMAGE_SCN_MEM_WRITE,
 592                           SectionKind::getDataRel());
 593   }
 594
 595
 596   if (T.isKnownWindowsMSVCEnvironment()) {
 597     StaticDtorSection =
 598       Ctx->getCOFFSection(".CRT$XTX",
 599                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 600                           COFF::IMAGE_SCN_MEM_READ,
 601                           SectionKind::getReadOnly());
 602   } else {
 603     StaticDtorSection =
 604       Ctx->getCOFFSection(".dtors",
 605                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 606                           COFF::IMAGE_SCN_MEM_READ |
 607                           COFF::IMAGE_SCN_MEM_WRITE,
 608                           SectionKind::getDataRel());
 609   }
 610
 611   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 612   // though it contains relocatable pointers.  In PIC mode, this is probably a
 613   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 614   // adjusted or this should be a data section.
 615   LSDASection =
 616     Ctx->getCOFFSection(".gcc_except_table",
 617                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 618                         COFF::IMAGE_SCN_MEM_READ,
 619                         SectionKind::getReadOnly());
 620
 621   // Debug info.
 622   COFFDebugSymbolsSection =
 623     Ctx->getCOFFSection(".debug$S",
 624                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 625                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 626                         COFF::IMAGE_SCN_MEM_READ,
 627                         SectionKind::getMetadata());
 628
 629   DwarfAbbrevSection =
 630     Ctx->getCOFFSection(".debug_abbrev",
 631                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 632                         COFF::IMAGE_SCN_MEM_READ,
 633                         SectionKind::getMetadata());
 634   DwarfInfoSection =
 635     Ctx->getCOFFSection(".debug_info",
 636                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 637                         COFF::IMAGE_SCN_MEM_READ,
 638                         SectionKind::getMetadata());
 639   DwarfLineSection =
 640     Ctx->getCOFFSection(".debug_line",
 641                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 642                         COFF::IMAGE_SCN_MEM_READ,
 643                         SectionKind::getMetadata());
 644   DwarfFrameSection =
 645     Ctx->getCOFFSection(".debug_frame",
 646                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 647                         COFF::IMAGE_SCN_MEM_READ,
 648                         SectionKind::getMetadata());
 649   DwarfPubNamesSection =
 650     Ctx->getCOFFSection(".debug_pubnames",
 651                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 652                         COFF::IMAGE_SCN_MEM_READ,
 653                         SectionKind::getMetadata());
 654   DwarfPubTypesSection =
 655     Ctx->getCOFFSection(".debug_pubtypes",
 656                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 657                         COFF::IMAGE_SCN_MEM_READ,
 658                         SectionKind::getMetadata());
 659   DwarfGnuPubNamesSection =
 660     Ctx->getCOFFSection(".debug_gnu_pubnames",
 661                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 662                         COFF::IMAGE_SCN_MEM_READ,
 663                         SectionKind::getMetadata());
 664   DwarfGnuPubTypesSection =
 665     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 666                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 667                         COFF::IMAGE_SCN_MEM_READ,
 668                         SectionKind::getMetadata());
 669   DwarfStrSection =
 670     Ctx->getCOFFSection(".debug_str",
 671                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 672                         COFF::IMAGE_SCN_MEM_READ,
 673                         SectionKind::getMetadata());
 674   DwarfLocSection =
 675     Ctx->getCOFFSection(".debug_loc",
 676                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 677                         COFF::IMAGE_SCN_MEM_READ,
 678                         SectionKind::getMetadata());
 679   DwarfARangesSection =
 680     Ctx->getCOFFSection(".debug_aranges",
 681                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 682                         COFF::IMAGE_SCN_MEM_READ,
 683                         SectionKind::getMetadata());
 684   DwarfRangesSection =
 685     Ctx->getCOFFSection(".debug_ranges",
 686                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 687                         COFF::IMAGE_SCN_MEM_READ,
 688                         SectionKind::getMetadata());
 689   DwarfMacroInfoSection =
 690     Ctx->getCOFFSection(".debug_macinfo",
 691                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 692                         COFF::IMAGE_SCN_MEM_READ,
 693                         SectionKind::getMetadata());
 694   DwarfInfoDWOSection =
 695       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 696                                                 COFF::IMAGE_SCN_MEM_READ,
 697                           SectionKind::getMetadata());
 698   DwarfAbbrevDWOSection =
 699       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 700                                                   COFF::IMAGE_SCN_MEM_READ,
 701                           SectionKind::getMetadata());
 702   DwarfStrDWOSection =
 703       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 704                                                COFF::IMAGE_SCN_MEM_READ,
 705                           SectionKind::getMetadata());
 706   DwarfLineDWOSection =
 707       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 708                                                 COFF::IMAGE_SCN_MEM_READ,
 709                           SectionKind::getMetadata());
 710   DwarfLocDWOSection =
 711       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 712                                                COFF::IMAGE_SCN_MEM_READ,
 713                           SectionKind::getMetadata());
 714   DwarfStrOffDWOSection =
 715       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 716                                                   COFF::IMAGE_SCN_MEM_READ,
 717                           SectionKind::getMetadata());
 718   DwarfAddrSection = Ctx->getCOFFSection(
 719       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 720       SectionKind::getMetadata());
 721
 722   DrectveSection =
 723     Ctx->getCOFFSection(".drectve",
 724                         COFF::IMAGE_SCN_LNK_INFO,
 725                         SectionKind::getMetadata());
 726
 727   PDataSection =
 728     Ctx->getCOFFSection(".pdata",
 729                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 730                         COFF::IMAGE_SCN_MEM_READ,
 731                         SectionKind::getDataRel());
 732
 733   XDataSection =
 734     Ctx->getCOFFSection(".xdata",
 735                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 736                         COFF::IMAGE_SCN_MEM_READ,
 737                         SectionKind::getDataRel());
 738   TLSDataSection =
 739     Ctx->getCOFFSection(".tls$",
 740                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 741                         COFF::IMAGE_SCN_MEM_READ |
 742                         COFF::IMAGE_SCN_MEM_WRITE,
 743                         SectionKind::getDataRel());
 744 }
 745
 746 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 747                                             CodeModel::Model cm,
 748                                             MCContext &ctx) {
 749   RelocM = relocm;
 750   CMModel = cm;
 751   Ctx = &ctx;
 752
 753   // Common.
 754   CommDirectiveSupportsAlignment = true;
 755   SupportsWeakOmittedEHFrame = true;
 756   IsFunctionEHFrameSymbolPrivate = true;
 757   SupportsCompactUnwindWithoutEHFrame = false;
 758
 759   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
 760     TTypeEncoding = dwarf::DW_EH_PE_absptr;
 761
 762   CompactUnwindDwarfEHFrameOnly = 0;
 763
 764   EHFrameSection = nullptr;             // Created on demand.
 765   CompactUnwindSection = nullptr;       // Used only by selected targets.
 766   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 767   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 768   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 769   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 770
 771   Triple T(TT);
 772   Triple::ArchType Arch = T.getArch();
 773   // FIXME: Checking for Arch here to filter out bogus triples such as
 774   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 775   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 776        Arch == Triple::arm || Arch == Triple::thumb ||
 777        Arch == Triple::arm64 ||
 778        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 779        Arch == Triple::UnknownArch) &&
 780       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 781     Env = IsMachO;
 782     InitMachOMCObjectFileInfo(T);
 783   } else if (T.isOSWindows() && T.getObjectFormat() == Triple::COFF) {
 784     assert((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 785             Arch == Triple::arm || Arch == Triple::thumb) &&
 786            "unsupported Windows COFF architecture");
 787     Env = IsCOFF;
 788     InitCOFFMCObjectFileInfo(T);
 789   } else {
 790     Env = IsELF;
 791     InitELFMCObjectFileInfo(T);
 792   }
 793 }
 794
 795 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 796   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 797                             SectionKind::getMetadata(), 0, utostr(Hash));
 798 }
 799
 800 const MCSection *
 801 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 802   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 803                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 804                             utostr(Hash));
 805 }
 806
 807 void MCObjectFileInfo::InitEHFrameSection() {
 808   if (Env == IsMachO)
 809     EHFrameSection =
 810       Ctx->getMachOSection("__TEXT", "__eh_frame",
 811                            MachO::S_COALESCED |
 812                            MachO::S_ATTR_NO_TOC |
 813                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 814                            MachO::S_ATTR_LIVE_SUPPORT,
 815                            SectionKind::getReadOnly());
 816   else if (Env == IsELF)
 817     EHFrameSection =
 818       Ctx->getELFSection(".eh_frame", EHSectionType,
 819                          EHSectionFlags,
 820                          SectionKind::getDataRel());
 821   else
 822     EHFrameSection =
 823       Ctx->getCOFFSection(".eh_frame",
 824                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 825                           COFF::IMAGE_SCN_MEM_READ |
 826                           COFF::IMAGE_SCN_MEM_WRITE,
 827                           SectionKind::getDataRel());
 828 }