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