lib/MC/MCObjectFileInfo.cpp

   1 //===-- MCObjectFileInfo.cpp - Object File Information --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/MC/MCObjectFileInfo.h"
  10 #include "llvm/ADT/StringExtras.h"
  11 #include "llvm/ADT/Triple.h"
  12 #include "llvm/BinaryFormat/COFF.h"
  13 #include "llvm/BinaryFormat/ELF.h"
  14 #include "llvm/MC/MCAsmInfo.h"
  15 #include "llvm/MC/MCContext.h"
  16 #include "llvm/MC/MCSection.h"
  17 #include "llvm/MC/MCSectionCOFF.h"
  18 #include "llvm/MC/MCSectionELF.h"
  19 #include "llvm/MC/MCSectionMachO.h"
  20 #include "llvm/MC/MCSectionWasm.h"
  21 #include "llvm/MC/MCSectionXCOFF.h"
  22
  23 using namespace llvm;
  24
  25 static bool useCompactUnwind(const Triple &T) {
  26   // Only on darwin.
  27   if (!T.isOSDarwin())
  28     return false;
  29
  30   // aarch64 always has it.
  31   if (T.getArch() == Triple::aarch64)
  32     return true;
  33
  34   // armv7k always has it.
  35   if (T.isWatchABI())
  36     return true;
  37
  38   // Use it on newer version of OS X.
  39   if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
  40     return true;
  41
  42   // And the iOS simulator.
  43   if (T.isiOS() &&
  44       (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
  45     return true;
  46
  47   return false;
  48 }
  49
  50 void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) {
  51   // MachO
  52   SupportsWeakOmittedEHFrame = false;
  53
  54   EHFrameSection = Ctx->getMachOSection(
  55       "__TEXT", "__eh_frame",
  56       MachO::S_COALESCED | MachO::S_ATTR_NO_TOC |
  57           MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT,
  58       SectionKind::getReadOnly());
  59
  60   if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
  61     SupportsCompactUnwindWithoutEHFrame = true;
  62
  63   if (T.isWatchABI())
  64     OmitDwarfIfHaveCompactUnwind = true;
  65
  66   FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  67
  68   // .comm doesn't support alignment before Leopard.
  69   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  70     CommDirectiveSupportsAlignment = false;
  71
  72   TextSection // .text
  73     = Ctx->getMachOSection("__TEXT", "__text",
  74                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  75                            SectionKind::getText());
  76   DataSection // .data
  77       = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData());
  78
  79   // BSSSection might not be expected initialized on msvc.
  80   BSSSection = nullptr;
  81
  82   TLSDataSection // .tdata
  83       = Ctx->getMachOSection("__DATA", "__thread_data",
  84                              MachO::S_THREAD_LOCAL_REGULAR,
  85                              SectionKind::getData());
  86   TLSBSSSection // .tbss
  87     = Ctx->getMachOSection("__DATA", "__thread_bss",
  88                            MachO::S_THREAD_LOCAL_ZEROFILL,
  89                            SectionKind::getThreadBSS());
  90
  91   // TODO: Verify datarel below.
  92   TLSTLVSection // .tlv
  93       = Ctx->getMachOSection("__DATA", "__thread_vars",
  94                              MachO::S_THREAD_LOCAL_VARIABLES,
  95                              SectionKind::getData());
  96
  97   TLSThreadInitSection = Ctx->getMachOSection(
  98       "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  99       SectionKind::getData());
 100
 101   CStringSection // .cstring
 102     = Ctx->getMachOSection("__TEXT", "__cstring",
 103                            MachO::S_CSTRING_LITERALS,
 104                            SectionKind::getMergeable1ByteCString());
 105   UStringSection
 106     = Ctx->getMachOSection("__TEXT","__ustring", 0,
 107                            SectionKind::getMergeable2ByteCString());
 108   FourByteConstantSection // .literal4
 109     = Ctx->getMachOSection("__TEXT", "__literal4",
 110                            MachO::S_4BYTE_LITERALS,
 111                            SectionKind::getMergeableConst4());
 112   EightByteConstantSection // .literal8
 113     = Ctx->getMachOSection("__TEXT", "__literal8",
 114                            MachO::S_8BYTE_LITERALS,
 115                            SectionKind::getMergeableConst8());
 116
 117   SixteenByteConstantSection // .literal16
 118       = Ctx->getMachOSection("__TEXT", "__literal16",
 119                              MachO::S_16BYTE_LITERALS,
 120                              SectionKind::getMergeableConst16());
 121
 122   ReadOnlySection  // .const
 123     = Ctx->getMachOSection("__TEXT", "__const", 0,
 124                            SectionKind::getReadOnly());
 125
 126   // If the target is not powerpc, map the coal sections to the non-coal
 127   // sections.
 128   //
 129   // "__TEXT/__textcoal_nt" => section "__TEXT/__text"
 130   // "__TEXT/__const_coal"  => section "__TEXT/__const"
 131   // "__DATA/__datacoal_nt" => section "__DATA/__data"
 132   Triple::ArchType ArchTy = T.getArch();
 133
 134   ConstDataSection  // .const_data
 135     = Ctx->getMachOSection("__DATA", "__const", 0,
 136                            SectionKind::getReadOnlyWithRel());
 137
 138   if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
 139     TextCoalSection
 140       = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
 141                              MachO::S_COALESCED |
 142                              MachO::S_ATTR_PURE_INSTRUCTIONS,
 143                              SectionKind::getText());
 144     ConstTextCoalSection
 145       = Ctx->getMachOSection("__TEXT", "__const_coal",
 146                              MachO::S_COALESCED,
 147                              SectionKind::getReadOnly());
 148     DataCoalSection = Ctx->getMachOSection(
 149         "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData());
 150     ConstDataCoalSection = DataCoalSection;
 151   } else {
 152     TextCoalSection = TextSection;
 153     ConstTextCoalSection = ReadOnlySection;
 154     DataCoalSection = DataSection;
 155     ConstDataCoalSection = ConstDataSection;
 156   }
 157
 158   DataCommonSection
 159     = Ctx->getMachOSection("__DATA","__common",
 160                            MachO::S_ZEROFILL,
 161                            SectionKind::getBSS());
 162   DataBSSSection
 163     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 164                            SectionKind::getBSS());
 165
 166
 167   LazySymbolPointerSection
 168     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 169                            MachO::S_LAZY_SYMBOL_POINTERS,
 170                            SectionKind::getMetadata());
 171   NonLazySymbolPointerSection
 172     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 173                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 174                            SectionKind::getMetadata());
 175
 176   ThreadLocalPointerSection
 177     = Ctx->getMachOSection("__DATA", "__thread_ptr",
 178                            MachO::S_THREAD_LOCAL_VARIABLE_POINTERS,
 179                            SectionKind::getMetadata());
 180
 181   // Exception Handling.
 182   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 183                                      SectionKind::getReadOnlyWithRel());
 184
 185   COFFDebugSymbolsSection = nullptr;
 186   COFFDebugTypesSection = nullptr;
 187   COFFGlobalTypeHashesSection = nullptr;
 188
 189   if (useCompactUnwind(T)) {
 190     CompactUnwindSection =
 191         Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
 192                              SectionKind::getReadOnly());
 193
 194     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 195       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_X86_64_MODE_DWARF
 196     else if (T.getArch() == Triple::aarch64)
 197       CompactUnwindDwarfEHFrameOnly = 0x03000000;  // UNWIND_ARM64_MODE_DWARF
 198     else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
 199       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_ARM_MODE_DWARF
 200   }
 201
 202   // Debug Information.
 203   DwarfDebugNamesSection =
 204       Ctx->getMachOSection("__DWARF", "__debug_names", MachO::S_ATTR_DEBUG,
 205                            SectionKind::getMetadata(), "debug_names_begin");
 206   DwarfAccelNamesSection =
 207       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
 208                            SectionKind::getMetadata(), "names_begin");
 209   DwarfAccelObjCSection =
 210       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
 211                            SectionKind::getMetadata(), "objc_begin");
 212   // 16 character section limit...
 213   DwarfAccelNamespaceSection =
 214       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
 215                            SectionKind::getMetadata(), "namespac_begin");
 216   DwarfAccelTypesSection =
 217       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
 218                            SectionKind::getMetadata(), "types_begin");
 219
 220   DwarfSwiftASTSection =
 221       Ctx->getMachOSection("__DWARF", "__swift_ast", MachO::S_ATTR_DEBUG,
 222                            SectionKind::getMetadata());
 223
 224   DwarfAbbrevSection =
 225       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
 226                            SectionKind::getMetadata(), "section_abbrev");
 227   DwarfInfoSection =
 228       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
 229                            SectionKind::getMetadata(), "section_info");
 230   DwarfLineSection =
 231       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
 232                            SectionKind::getMetadata(), "section_line");
 233   DwarfLineStrSection =
 234       Ctx->getMachOSection("__DWARF", "__debug_line_str", MachO::S_ATTR_DEBUG,
 235                            SectionKind::getMetadata(), "section_line_str");
 236   DwarfFrameSection =
 237       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
 238                            SectionKind::getMetadata());
 239   DwarfPubNamesSection =
 240       Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
 241                            SectionKind::getMetadata());
 242   DwarfPubTypesSection =
 243       Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
 244                            SectionKind::getMetadata());
 245   DwarfGnuPubNamesSection =
 246       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
 247                            SectionKind::getMetadata());
 248   DwarfGnuPubTypesSection =
 249       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
 250                            SectionKind::getMetadata());
 251   DwarfStrSection =
 252       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
 253                            SectionKind::getMetadata(), "info_string");
 254   DwarfStrOffSection =
 255       Ctx->getMachOSection("__DWARF", "__debug_str_offs", MachO::S_ATTR_DEBUG,
 256                            SectionKind::getMetadata(), "section_str_off");
 257   DwarfAddrSection =
 258       Ctx->getMachOSection("__DWARF", "__debug_addr", MachO::S_ATTR_DEBUG,
 259                            SectionKind::getMetadata(), "section_info");
 260   DwarfLocSection =
 261       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
 262                            SectionKind::getMetadata(), "section_debug_loc");
 263   DwarfLoclistsSection =
 264       Ctx->getMachOSection("__DWARF", "__debug_loclists", MachO::S_ATTR_DEBUG,
 265                            SectionKind::getMetadata(), "section_debug_loc");
 266
 267   DwarfARangesSection =
 268       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
 269                            SectionKind::getMetadata());
 270   DwarfRangesSection =
 271       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
 272                            SectionKind::getMetadata(), "debug_range");
 273   DwarfRnglistsSection =
 274       Ctx->getMachOSection("__DWARF", "__debug_rnglists", MachO::S_ATTR_DEBUG,
 275                            SectionKind::getMetadata(), "debug_range");
 276   DwarfMacinfoSection =
 277       Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG,
 278                            SectionKind::getMetadata(), "debug_macinfo");
 279   DwarfDebugInlineSection =
 280       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
 281                            SectionKind::getMetadata());
 282   DwarfCUIndexSection =
 283       Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
 284                            SectionKind::getMetadata());
 285   DwarfTUIndexSection =
 286       Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG,
 287                            SectionKind::getMetadata());
 288   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
 289                                          0, SectionKind::getMetadata());
 290
 291   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
 292                                          0, SectionKind::getMetadata());
 293
 294   RemarksSection = Ctx->getMachOSection(
 295       "__LLVM", "__remarks", MachO::S_ATTR_DEBUG, SectionKind::getMetadata());
 296
 297   TLSExtraDataSection = TLSTLVSection;
 298 }
 299
 300 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
 301   switch (T.getArch()) {
 302   case Triple::mips:
 303   case Triple::mipsel:
 304   case Triple::mips64:
 305   case Triple::mips64el:
 306     FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4
 307                          ? dwarf::DW_EH_PE_sdata4
 308                          : dwarf::DW_EH_PE_sdata8;
 309     break;
 310   case Triple::ppc64:
 311   case Triple::ppc64le:
 312   case Triple::x86_64:
 313     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
 314                      (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
 315     break;
 316   case Triple::bpfel:
 317   case Triple::bpfeb:
 318     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 319     break;
 320   case Triple::hexagon:
 321     FDECFIEncoding =
 322         PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr;
 323     break;
 324   default:
 325     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 326     break;
 327   }
 328
 329   unsigned EHSectionType = T.getArch() == Triple::x86_64
 330                                ? ELF::SHT_X86_64_UNWIND
 331                                : ELF::SHT_PROGBITS;
 332
 333   // Solaris requires different flags for .eh_frame to seemingly every other
 334   // platform.
 335   unsigned EHSectionFlags = ELF::SHF_ALLOC;
 336   if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
 337     EHSectionFlags |= ELF::SHF_WRITE;
 338
 339   // ELF
 340   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 341                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
 342
 343   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 344                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
 345
 346   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 347                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
 348
 349   ReadOnlySection =
 350       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 351
 352   TLSDataSection =
 353       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 354                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 355
 356   TLSBSSSection = Ctx->getELFSection(
 357       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 358
 359   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 360                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
 361
 362   MergeableConst4Section =
 363       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 364                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
 365
 366   MergeableConst8Section =
 367       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 368                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
 369
 370   MergeableConst16Section =
 371       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 372                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
 373
 374   MergeableConst32Section =
 375       Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
 376                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
 377
 378   // Exception Handling Sections.
 379
 380   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 381   // it contains relocatable pointers.  In PIC mode, this is probably a big
 382   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 383   // adjusted or this should be a data section.
 384   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 385                                    ELF::SHF_ALLOC);
 386
 387   COFFDebugSymbolsSection = nullptr;
 388   COFFDebugTypesSection = nullptr;
 389
 390   unsigned DebugSecType = ELF::SHT_PROGBITS;
 391
 392   // MIPS .debug_* sections should have SHT_MIPS_DWARF section type
 393   // to distinguish among sections contain DWARF and ECOFF debug formats.
 394   // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS.
 395   if (T.isMIPS())
 396     DebugSecType = ELF::SHT_MIPS_DWARF;
 397
 398   // Debug Info Sections.
 399   DwarfAbbrevSection =
 400       Ctx->getELFSection(".debug_abbrev", DebugSecType, 0);
 401   DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0);
 402   DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0);
 403   DwarfLineStrSection =
 404       Ctx->getELFSection(".debug_line_str", DebugSecType,
 405                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 406   DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0);
 407   DwarfPubNamesSection =
 408       Ctx->getELFSection(".debug_pubnames", DebugSecType, 0);
 409   DwarfPubTypesSection =
 410       Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0);
 411   DwarfGnuPubNamesSection =
 412       Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0);
 413   DwarfGnuPubTypesSection =
 414       Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0);
 415   DwarfStrSection =
 416       Ctx->getELFSection(".debug_str", DebugSecType,
 417                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 418   DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0);
 419   DwarfARangesSection =
 420       Ctx->getELFSection(".debug_aranges", DebugSecType, 0);
 421   DwarfRangesSection =
 422       Ctx->getELFSection(".debug_ranges", DebugSecType, 0);
 423   DwarfMacinfoSection =
 424       Ctx->getELFSection(".debug_macinfo", DebugSecType, 0);
 425
 426   // DWARF5 Experimental Debug Info
 427
 428   // Accelerator Tables
 429   DwarfDebugNamesSection =
 430       Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0);
 431   DwarfAccelNamesSection =
 432       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
 433   DwarfAccelObjCSection =
 434       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
 435   DwarfAccelNamespaceSection =
 436       Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
 437   DwarfAccelTypesSection =
 438       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
 439
 440   // String Offset and Address Sections
 441   DwarfStrOffSection =
 442       Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0);
 443   DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0);
 444   DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0);
 445   DwarfLoclistsSection = Ctx->getELFSection(".debug_loclists", DebugSecType, 0);
 446
 447   // Fission Sections
 448   DwarfInfoDWOSection =
 449       Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE);
 450   DwarfTypesDWOSection =
 451       Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE);
 452   DwarfAbbrevDWOSection =
 453       Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE);
 454   DwarfStrDWOSection = Ctx->getELFSection(
 455       ".debug_str.dwo", DebugSecType,
 456       ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, "");
 457   DwarfLineDWOSection =
 458       Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE);
 459   DwarfLocDWOSection =
 460       Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE);
 461   DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo",
 462                                              DebugSecType, ELF::SHF_EXCLUDE);
 463   DwarfRnglistsDWOSection =
 464       Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE);
 465
 466   // DWP Sections
 467   DwarfCUIndexSection =
 468       Ctx->getELFSection(".debug_cu_index", DebugSecType, 0);
 469   DwarfTUIndexSection =
 470       Ctx->getELFSection(".debug_tu_index", DebugSecType, 0);
 471
 472   StackMapSection =
 473       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 474
 475   FaultMapSection =
 476       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 477
 478   EHFrameSection =
 479       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 480
 481   StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0);
 482
 483   RemarksSection =
 484       Ctx->getELFSection(".remarks", ELF::SHT_PROGBITS, ELF::SHF_EXCLUDE);
 485 }
 486
 487 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
 488   EHFrameSection =
 489       Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 490                                            COFF::IMAGE_SCN_MEM_READ,
 491                           SectionKind::getData());
 492
 493   // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode.  This is
 494   // used to indicate to the linker that the text segment contains thumb instructions
 495   // and to set the ISA selection bit for calls accordingly.
 496   const bool IsThumb = T.getArch() == Triple::thumb;
 497
 498   CommDirectiveSupportsAlignment = true;
 499
 500   // COFF
 501   BSSSection = Ctx->getCOFFSection(
 502       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 503                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 504       SectionKind::getBSS());
 505   TextSection = Ctx->getCOFFSection(
 506       ".text",
 507       (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
 508           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
 509           COFF::IMAGE_SCN_MEM_READ,
 510       SectionKind::getText());
 511   DataSection = Ctx->getCOFFSection(
 512       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 513                    COFF::IMAGE_SCN_MEM_WRITE,
 514       SectionKind::getData());
 515   ReadOnlySection = Ctx->getCOFFSection(
 516       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 517       SectionKind::getReadOnly());
 518
 519   if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::aarch64) {
 520     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 521     LSDASection = nullptr;
 522   } else {
 523     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 524                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 525                                           COFF::IMAGE_SCN_MEM_READ,
 526                                       SectionKind::getReadOnly());
 527   }
 528
 529   // Debug info.
 530   COFFDebugSymbolsSection =
 531       Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
 532                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 533                                        COFF::IMAGE_SCN_MEM_READ),
 534                           SectionKind::getMetadata());
 535   COFFDebugTypesSection =
 536       Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
 537                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 538                                        COFF::IMAGE_SCN_MEM_READ),
 539                           SectionKind::getMetadata());
 540   COFFGlobalTypeHashesSection = Ctx->getCOFFSection(
 541       ".debug$H",
 542       (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 543        COFF::IMAGE_SCN_MEM_READ),
 544       SectionKind::getMetadata());
 545
 546   DwarfAbbrevSection = Ctx->getCOFFSection(
 547       ".debug_abbrev",
 548       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 549           COFF::IMAGE_SCN_MEM_READ,
 550       SectionKind::getMetadata(), "section_abbrev");
 551   DwarfInfoSection = Ctx->getCOFFSection(
 552       ".debug_info",
 553       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 554           COFF::IMAGE_SCN_MEM_READ,
 555       SectionKind::getMetadata(), "section_info");
 556   DwarfLineSection = Ctx->getCOFFSection(
 557       ".debug_line",
 558       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 559           COFF::IMAGE_SCN_MEM_READ,
 560       SectionKind::getMetadata(), "section_line");
 561   DwarfLineStrSection = Ctx->getCOFFSection(
 562       ".debug_line_str",
 563       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 564           COFF::IMAGE_SCN_MEM_READ,
 565       SectionKind::getMetadata(), "section_line_str");
 566   DwarfFrameSection = Ctx->getCOFFSection(
 567       ".debug_frame",
 568       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 569           COFF::IMAGE_SCN_MEM_READ,
 570       SectionKind::getMetadata());
 571   DwarfPubNamesSection = Ctx->getCOFFSection(
 572       ".debug_pubnames",
 573       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 574           COFF::IMAGE_SCN_MEM_READ,
 575       SectionKind::getMetadata());
 576   DwarfPubTypesSection = Ctx->getCOFFSection(
 577       ".debug_pubtypes",
 578       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 579           COFF::IMAGE_SCN_MEM_READ,
 580       SectionKind::getMetadata());
 581   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
 582       ".debug_gnu_pubnames",
 583       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 584           COFF::IMAGE_SCN_MEM_READ,
 585       SectionKind::getMetadata());
 586   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
 587       ".debug_gnu_pubtypes",
 588       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 589           COFF::IMAGE_SCN_MEM_READ,
 590       SectionKind::getMetadata());
 591   DwarfStrSection = Ctx->getCOFFSection(
 592       ".debug_str",
 593       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 594           COFF::IMAGE_SCN_MEM_READ,
 595       SectionKind::getMetadata(), "info_string");
 596   DwarfStrOffSection = Ctx->getCOFFSection(
 597       ".debug_str_offsets",
 598       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 599           COFF::IMAGE_SCN_MEM_READ,
 600       SectionKind::getMetadata(), "section_str_off");
 601   DwarfLocSection = Ctx->getCOFFSection(
 602       ".debug_loc",
 603       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 604           COFF::IMAGE_SCN_MEM_READ,
 605       SectionKind::getMetadata(), "section_debug_loc");
 606   DwarfARangesSection = Ctx->getCOFFSection(
 607       ".debug_aranges",
 608       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 609           COFF::IMAGE_SCN_MEM_READ,
 610       SectionKind::getMetadata());
 611   DwarfRangesSection = Ctx->getCOFFSection(
 612       ".debug_ranges",
 613       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 614           COFF::IMAGE_SCN_MEM_READ,
 615       SectionKind::getMetadata(), "debug_range");
 616   DwarfMacinfoSection = Ctx->getCOFFSection(
 617       ".debug_macinfo",
 618       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 619           COFF::IMAGE_SCN_MEM_READ,
 620       SectionKind::getMetadata(), "debug_macinfo");
 621   DwarfInfoDWOSection = Ctx->getCOFFSection(
 622       ".debug_info.dwo",
 623       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 624           COFF::IMAGE_SCN_MEM_READ,
 625       SectionKind::getMetadata(), "section_info_dwo");
 626   DwarfTypesDWOSection = Ctx->getCOFFSection(
 627       ".debug_types.dwo",
 628       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 629           COFF::IMAGE_SCN_MEM_READ,
 630       SectionKind::getMetadata(), "section_types_dwo");
 631   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
 632       ".debug_abbrev.dwo",
 633       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 634           COFF::IMAGE_SCN_MEM_READ,
 635       SectionKind::getMetadata(), "section_abbrev_dwo");
 636   DwarfStrDWOSection = Ctx->getCOFFSection(
 637       ".debug_str.dwo",
 638       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 639           COFF::IMAGE_SCN_MEM_READ,
 640       SectionKind::getMetadata(), "skel_string");
 641   DwarfLineDWOSection = Ctx->getCOFFSection(
 642       ".debug_line.dwo",
 643       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 644           COFF::IMAGE_SCN_MEM_READ,
 645       SectionKind::getMetadata());
 646   DwarfLocDWOSection = Ctx->getCOFFSection(
 647       ".debug_loc.dwo",
 648       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 649           COFF::IMAGE_SCN_MEM_READ,
 650       SectionKind::getMetadata(), "skel_loc");
 651   DwarfStrOffDWOSection = Ctx->getCOFFSection(
 652       ".debug_str_offsets.dwo",
 653       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 654           COFF::IMAGE_SCN_MEM_READ,
 655       SectionKind::getMetadata(), "section_str_off_dwo");
 656   DwarfAddrSection = Ctx->getCOFFSection(
 657       ".debug_addr",
 658       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 659           COFF::IMAGE_SCN_MEM_READ,
 660       SectionKind::getMetadata(), "addr_sec");
 661   DwarfCUIndexSection = Ctx->getCOFFSection(
 662       ".debug_cu_index",
 663       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 664           COFF::IMAGE_SCN_MEM_READ,
 665       SectionKind::getMetadata());
 666   DwarfTUIndexSection = Ctx->getCOFFSection(
 667       ".debug_tu_index",
 668       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 669           COFF::IMAGE_SCN_MEM_READ,
 670       SectionKind::getMetadata());
 671   DwarfDebugNamesSection = Ctx->getCOFFSection(
 672       ".debug_names",
 673       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 674           COFF::IMAGE_SCN_MEM_READ,
 675       SectionKind::getMetadata(), "debug_names_begin");
 676   DwarfAccelNamesSection = Ctx->getCOFFSection(
 677       ".apple_names",
 678       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 679           COFF::IMAGE_SCN_MEM_READ,
 680       SectionKind::getMetadata(), "names_begin");
 681   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
 682       ".apple_namespaces",
 683       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 684           COFF::IMAGE_SCN_MEM_READ,
 685       SectionKind::getMetadata(), "namespac_begin");
 686   DwarfAccelTypesSection = Ctx->getCOFFSection(
 687       ".apple_types",
 688       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 689           COFF::IMAGE_SCN_MEM_READ,
 690       SectionKind::getMetadata(), "types_begin");
 691   DwarfAccelObjCSection = Ctx->getCOFFSection(
 692       ".apple_objc",
 693       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 694           COFF::IMAGE_SCN_MEM_READ,
 695       SectionKind::getMetadata(), "objc_begin");
 696
 697   DrectveSection = Ctx->getCOFFSection(
 698       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 699       SectionKind::getMetadata());
 700
 701   PDataSection = Ctx->getCOFFSection(
 702       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 703       SectionKind::getData());
 704
 705   XDataSection = Ctx->getCOFFSection(
 706       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 707       SectionKind::getData());
 708
 709   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
 710                                       SectionKind::getMetadata());
 711
 712   GFIDsSection = Ctx->getCOFFSection(".gfids$y",
 713                                      COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 714                                          COFF::IMAGE_SCN_MEM_READ,
 715                                      SectionKind::getMetadata());
 716
 717   TLSDataSection = Ctx->getCOFFSection(
 718       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 719                    COFF::IMAGE_SCN_MEM_WRITE,
 720       SectionKind::getData());
 721
 722   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
 723                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 724                                             COFF::IMAGE_SCN_MEM_READ,
 725                                         SectionKind::getReadOnly());
 726 }
 727
 728 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) {
 729   TextSection = Ctx->getWasmSection(".text", SectionKind::getText());
 730   DataSection = Ctx->getWasmSection(".data", SectionKind::getData());
 731
 732   DwarfLineSection =
 733       Ctx->getWasmSection(".debug_line", SectionKind::getMetadata());
 734   DwarfLineStrSection =
 735       Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata());
 736   DwarfStrSection =
 737       Ctx->getWasmSection(".debug_str", SectionKind::getMetadata());
 738   DwarfLocSection =
 739       Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata());
 740   DwarfAbbrevSection =
 741       Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata());
 742   DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata());
 743   DwarfRangesSection =
 744       Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata());
 745   DwarfMacinfoSection =
 746       Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata());
 747   DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata());
 748   DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata());
 749   DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata());
 750   DwarfInfoSection =
 751       Ctx->getWasmSection(".debug_info", SectionKind::getMetadata());
 752   DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata());
 753   DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata());
 754   DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata());
 755
 756   // Wasm use data section for LSDA.
 757   // TODO Consider putting each function's exception table in a separate
 758   // section, as in -function-sections, to facilitate lld's --gc-section.
 759   LSDASection = Ctx->getWasmSection(".rodata.gcc_except_table",
 760                                     SectionKind::getReadOnlyWithRel());
 761
 762   // TODO: Define more sections.
 763 }
 764
 765 void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) {
 766   // The default csect for program code. Functions without a specified section
 767   // get placed into this csect. The choice of csect name is not a property of
 768   // the ABI or object file format. For example, the XL compiler uses an unnamed
 769   // csect for program code.
 770   TextSection = Ctx->getXCOFFSection(
 771       ".text", XCOFF::StorageMappingClass::XMC_PR, XCOFF::XTY_SD,
 772       XCOFF::C_HIDEXT, SectionKind::getText());
 773
 774   DataSection = Ctx->getXCOFFSection(
 775       ".data", XCOFF::StorageMappingClass::XMC_RW, XCOFF::XTY_SD,
 776       XCOFF::C_HIDEXT, SectionKind::getData());
 777 }
 778
 779 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
 780                                             MCContext &ctx,
 781                                             bool LargeCodeModel) {
 782   PositionIndependent = PIC;
 783   Ctx = &ctx;
 784
 785   // Common.
 786   CommDirectiveSupportsAlignment = true;
 787   SupportsWeakOmittedEHFrame = true;
 788   SupportsCompactUnwindWithoutEHFrame = false;
 789   OmitDwarfIfHaveCompactUnwind = false;
 790
 791   FDECFIEncoding = dwarf::DW_EH_PE_absptr;
 792
 793   CompactUnwindDwarfEHFrameOnly = 0;
 794
 795   EHFrameSection = nullptr;             // Created on demand.
 796   CompactUnwindSection = nullptr;       // Used only by selected targets.
 797   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 798   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 799   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 800   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 801
 802   TT = TheTriple;
 803
 804   switch (TT.getObjectFormat()) {
 805   case Triple::MachO:
 806     Env = IsMachO;
 807     initMachOMCObjectFileInfo(TT);
 808     break;
 809   case Triple::COFF:
 810     if (!TT.isOSWindows())
 811       report_fatal_error(
 812           "Cannot initialize MC for non-Windows COFF object files.");
 813
 814     Env = IsCOFF;
 815     initCOFFMCObjectFileInfo(TT);
 816     break;
 817   case Triple::ELF:
 818     Env = IsELF;
 819     initELFMCObjectFileInfo(TT, LargeCodeModel);
 820     break;
 821   case Triple::Wasm:
 822     Env = IsWasm;
 823     initWasmMCObjectFileInfo(TT);
 824     break;
 825   case Triple::XCOFF:
 826     Env = IsXCOFF;
 827     initXCOFFMCObjectFileInfo(TT);
 828     break;
 829   case Triple::UnknownObjectFormat:
 830     report_fatal_error("Cannot initialize MC for unknown object file format.");
 831     break;
 832   }
 833 }
 834
 835 MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name,
 836                                                    uint64_t Hash) const {
 837   switch (TT.getObjectFormat()) {
 838   case Triple::ELF:
 839     return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0,
 840                               utostr(Hash));
 841   case Triple::MachO:
 842   case Triple::COFF:
 843   case Triple::Wasm:
 844   case Triple::XCOFF:
 845   case Triple::UnknownObjectFormat:
 846     report_fatal_error("Cannot get DWARF comdat section for this object file "
 847                        "format: not implemented.");
 848     break;
 849   }
 850   llvm_unreachable("Unknown ObjectFormatType");
 851 }
 852
 853 MCSection *
 854 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const {
 855   if (Env != IsELF)
 856     return StackSizesSection;
 857
 858   const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec);
 859   unsigned Flags = ELF::SHF_LINK_ORDER;
 860   StringRef GroupName;
 861   if (const MCSymbol *Group = ElfSec.getGroup()) {
 862     GroupName = Group->getName();
 863     Flags |= ELF::SHF_GROUP;
 864   }
 865
 866   const MCSymbol *Link = TextSec.getBeginSymbol();
 867   auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()});
 868   unsigned UniqueID = It.first->second;
 869
 870   return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0,
 871                             GroupName, UniqueID, cast<MCSymbolELF>(Link));
 872 }