xref: /freebsd/contrib/llvm-project/llvm/lib/MC/MCObjectFileInfo.cpp (revision 9e5787d2284e187abb5b654d924394a65772e004)
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 || T.getArch() == Triple::aarch64_32)
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() && T.isX86())
44     return true;
45 
46   return false;
47 }
48 
49 void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) {
50   // MachO
51   SupportsWeakOmittedEHFrame = false;
52 
53   EHFrameSection = Ctx->getMachOSection(
54       "__TEXT", "__eh_frame",
55       MachO::S_COALESCED | MachO::S_ATTR_NO_TOC |
56           MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT,
57       SectionKind::getReadOnly());
58 
59   if (T.isOSDarwin() &&
60       (T.getArch() == Triple::aarch64 || T.getArch() == Triple::aarch64_32))
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.isX86())
195       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_X86_64_MODE_DWARF
196     else if (T.getArch() == Triple::aarch64 || T.getArch() == Triple::aarch64_32)
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   DwarfMacroSection =
280       Ctx->getMachOSection("__DWARF", "__debug_macro", MachO::S_ATTR_DEBUG,
281                            SectionKind::getMetadata(), "debug_macro");
282   DwarfDebugInlineSection =
283       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
284                            SectionKind::getMetadata());
285   DwarfCUIndexSection =
286       Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
287                            SectionKind::getMetadata());
288   DwarfTUIndexSection =
289       Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG,
290                            SectionKind::getMetadata());
291   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
292                                          0, SectionKind::getMetadata());
293 
294   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
295                                          0, SectionKind::getMetadata());
296 
297   RemarksSection = Ctx->getMachOSection(
298       "__LLVM", "__remarks", MachO::S_ATTR_DEBUG, SectionKind::getMetadata());
299 
300   TLSExtraDataSection = TLSTLVSection;
301 }
302 
303 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
304   switch (T.getArch()) {
305   case Triple::mips:
306   case Triple::mipsel:
307   case Triple::mips64:
308   case Triple::mips64el:
309     // We cannot use DW_EH_PE_sdata8 for the large PositionIndependent case
310     // since there is no R_MIPS_PC64 relocation (only a 32-bit version).
311     if (PositionIndependent && !Large)
312       FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
313     else
314       FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4
315                            ? dwarf::DW_EH_PE_sdata4
316                            : dwarf::DW_EH_PE_sdata8;
317     break;
318   case Triple::ppc64:
319   case Triple::ppc64le:
320   case Triple::x86_64:
321     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
322                      (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
323     break;
324   case Triple::bpfel:
325   case Triple::bpfeb:
326     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
327     break;
328   case Triple::hexagon:
329     FDECFIEncoding =
330         PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr;
331     break;
332   default:
333     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
334     break;
335   }
336 
337   unsigned EHSectionType = T.getArch() == Triple::x86_64
338                                ? ELF::SHT_X86_64_UNWIND
339                                : ELF::SHT_PROGBITS;
340 
341   // Solaris requires different flags for .eh_frame to seemingly every other
342   // platform.
343   unsigned EHSectionFlags = ELF::SHF_ALLOC;
344   if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
345     EHSectionFlags |= ELF::SHF_WRITE;
346 
347   // ELF
348   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
349                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
350 
351   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
352                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
353 
354   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
355                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
356 
357   ReadOnlySection =
358       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
359 
360   TLSDataSection =
361       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
362                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
363 
364   TLSBSSSection = Ctx->getELFSection(
365       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
366 
367   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
368                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
369 
370   MergeableConst4Section =
371       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
372                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
373 
374   MergeableConst8Section =
375       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
376                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
377 
378   MergeableConst16Section =
379       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
380                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
381 
382   MergeableConst32Section =
383       Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
384                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
385 
386   // Exception Handling Sections.
387 
388   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
389   // it contains relocatable pointers.  In PIC mode, this is probably a big
390   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
391   // adjusted or this should be a data section.
392   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
393                                    ELF::SHF_ALLOC);
394 
395   COFFDebugSymbolsSection = nullptr;
396   COFFDebugTypesSection = nullptr;
397 
398   unsigned DebugSecType = ELF::SHT_PROGBITS;
399 
400   // MIPS .debug_* sections should have SHT_MIPS_DWARF section type
401   // to distinguish among sections contain DWARF and ECOFF debug formats.
402   // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS.
403   if (T.isMIPS())
404     DebugSecType = ELF::SHT_MIPS_DWARF;
405 
406   // Debug Info Sections.
407   DwarfAbbrevSection =
408       Ctx->getELFSection(".debug_abbrev", DebugSecType, 0);
409   DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0);
410   DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0);
411   DwarfLineStrSection =
412       Ctx->getELFSection(".debug_line_str", DebugSecType,
413                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
414   DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0);
415   DwarfPubNamesSection =
416       Ctx->getELFSection(".debug_pubnames", DebugSecType, 0);
417   DwarfPubTypesSection =
418       Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0);
419   DwarfGnuPubNamesSection =
420       Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0);
421   DwarfGnuPubTypesSection =
422       Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0);
423   DwarfStrSection =
424       Ctx->getELFSection(".debug_str", DebugSecType,
425                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
426   DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0);
427   DwarfARangesSection =
428       Ctx->getELFSection(".debug_aranges", DebugSecType, 0);
429   DwarfRangesSection =
430       Ctx->getELFSection(".debug_ranges", DebugSecType, 0);
431   DwarfMacinfoSection =
432       Ctx->getELFSection(".debug_macinfo", DebugSecType, 0);
433   DwarfMacroSection = Ctx->getELFSection(".debug_macro", DebugSecType, 0);
434 
435   // DWARF5 Experimental Debug Info
436 
437   // Accelerator Tables
438   DwarfDebugNamesSection =
439       Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0);
440   DwarfAccelNamesSection =
441       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
442   DwarfAccelObjCSection =
443       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
444   DwarfAccelNamespaceSection =
445       Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
446   DwarfAccelTypesSection =
447       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
448 
449   // String Offset and Address Sections
450   DwarfStrOffSection =
451       Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0);
452   DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0);
453   DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0);
454   DwarfLoclistsSection = Ctx->getELFSection(".debug_loclists", DebugSecType, 0);
455 
456   // Fission Sections
457   DwarfInfoDWOSection =
458       Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE);
459   DwarfTypesDWOSection =
460       Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE);
461   DwarfAbbrevDWOSection =
462       Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE);
463   DwarfStrDWOSection = Ctx->getELFSection(
464       ".debug_str.dwo", DebugSecType,
465       ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, "");
466   DwarfLineDWOSection =
467       Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE);
468   DwarfLocDWOSection =
469       Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE);
470   DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo",
471                                              DebugSecType, ELF::SHF_EXCLUDE);
472   DwarfRnglistsDWOSection =
473       Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE);
474   DwarfMacinfoDWOSection =
475       Ctx->getELFSection(".debug_macinfo.dwo", DebugSecType, ELF::SHF_EXCLUDE);
476   DwarfMacroDWOSection =
477       Ctx->getELFSection(".debug_macro.dwo", DebugSecType, ELF::SHF_EXCLUDE);
478 
479   DwarfLoclistsDWOSection =
480       Ctx->getELFSection(".debug_loclists.dwo", DebugSecType, ELF::SHF_EXCLUDE);
481 
482   // DWP Sections
483   DwarfCUIndexSection =
484       Ctx->getELFSection(".debug_cu_index", DebugSecType, 0);
485   DwarfTUIndexSection =
486       Ctx->getELFSection(".debug_tu_index", DebugSecType, 0);
487 
488   StackMapSection =
489       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
490 
491   FaultMapSection =
492       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
493 
494   EHFrameSection =
495       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
496 
497   StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0);
498 }
499 
500 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
501   EHFrameSection =
502       Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
503                                            COFF::IMAGE_SCN_MEM_READ,
504                           SectionKind::getData());
505 
506   // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode.  This is
507   // used to indicate to the linker that the text segment contains thumb instructions
508   // and to set the ISA selection bit for calls accordingly.
509   const bool IsThumb = T.getArch() == Triple::thumb;
510 
511   CommDirectiveSupportsAlignment = true;
512 
513   // COFF
514   BSSSection = Ctx->getCOFFSection(
515       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
516                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
517       SectionKind::getBSS());
518   TextSection = Ctx->getCOFFSection(
519       ".text",
520       (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
521           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
522           COFF::IMAGE_SCN_MEM_READ,
523       SectionKind::getText());
524   DataSection = Ctx->getCOFFSection(
525       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
526                    COFF::IMAGE_SCN_MEM_WRITE,
527       SectionKind::getData());
528   ReadOnlySection = Ctx->getCOFFSection(
529       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
530       SectionKind::getReadOnly());
531 
532   if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::aarch64) {
533     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
534     LSDASection = nullptr;
535   } else {
536     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
537                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
538                                           COFF::IMAGE_SCN_MEM_READ,
539                                       SectionKind::getReadOnly());
540   }
541 
542   // Debug info.
543   COFFDebugSymbolsSection =
544       Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
545                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
546                                        COFF::IMAGE_SCN_MEM_READ),
547                           SectionKind::getMetadata());
548   COFFDebugTypesSection =
549       Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
550                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
551                                        COFF::IMAGE_SCN_MEM_READ),
552                           SectionKind::getMetadata());
553   COFFGlobalTypeHashesSection = Ctx->getCOFFSection(
554       ".debug$H",
555       (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
556        COFF::IMAGE_SCN_MEM_READ),
557       SectionKind::getMetadata());
558 
559   DwarfAbbrevSection = Ctx->getCOFFSection(
560       ".debug_abbrev",
561       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
562           COFF::IMAGE_SCN_MEM_READ,
563       SectionKind::getMetadata(), "section_abbrev");
564   DwarfInfoSection = Ctx->getCOFFSection(
565       ".debug_info",
566       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
567           COFF::IMAGE_SCN_MEM_READ,
568       SectionKind::getMetadata(), "section_info");
569   DwarfLineSection = Ctx->getCOFFSection(
570       ".debug_line",
571       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
572           COFF::IMAGE_SCN_MEM_READ,
573       SectionKind::getMetadata(), "section_line");
574   DwarfLineStrSection = Ctx->getCOFFSection(
575       ".debug_line_str",
576       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
577           COFF::IMAGE_SCN_MEM_READ,
578       SectionKind::getMetadata(), "section_line_str");
579   DwarfFrameSection = Ctx->getCOFFSection(
580       ".debug_frame",
581       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
582           COFF::IMAGE_SCN_MEM_READ,
583       SectionKind::getMetadata());
584   DwarfPubNamesSection = Ctx->getCOFFSection(
585       ".debug_pubnames",
586       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
587           COFF::IMAGE_SCN_MEM_READ,
588       SectionKind::getMetadata());
589   DwarfPubTypesSection = Ctx->getCOFFSection(
590       ".debug_pubtypes",
591       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
592           COFF::IMAGE_SCN_MEM_READ,
593       SectionKind::getMetadata());
594   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
595       ".debug_gnu_pubnames",
596       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
597           COFF::IMAGE_SCN_MEM_READ,
598       SectionKind::getMetadata());
599   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
600       ".debug_gnu_pubtypes",
601       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
602           COFF::IMAGE_SCN_MEM_READ,
603       SectionKind::getMetadata());
604   DwarfStrSection = Ctx->getCOFFSection(
605       ".debug_str",
606       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
607           COFF::IMAGE_SCN_MEM_READ,
608       SectionKind::getMetadata(), "info_string");
609   DwarfStrOffSection = Ctx->getCOFFSection(
610       ".debug_str_offsets",
611       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
612           COFF::IMAGE_SCN_MEM_READ,
613       SectionKind::getMetadata(), "section_str_off");
614   DwarfLocSection = Ctx->getCOFFSection(
615       ".debug_loc",
616       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
617           COFF::IMAGE_SCN_MEM_READ,
618       SectionKind::getMetadata(), "section_debug_loc");
619   DwarfLoclistsSection = Ctx->getCOFFSection(
620       ".debug_loclists",
621       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
622           COFF::IMAGE_SCN_MEM_READ,
623       SectionKind::getMetadata(), "section_debug_loclists");
624   DwarfARangesSection = Ctx->getCOFFSection(
625       ".debug_aranges",
626       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
627           COFF::IMAGE_SCN_MEM_READ,
628       SectionKind::getMetadata());
629   DwarfRangesSection = Ctx->getCOFFSection(
630       ".debug_ranges",
631       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
632           COFF::IMAGE_SCN_MEM_READ,
633       SectionKind::getMetadata(), "debug_range");
634   DwarfRnglistsSection = Ctx->getCOFFSection(
635       ".debug_rnglists",
636       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
637           COFF::IMAGE_SCN_MEM_READ,
638       SectionKind::getMetadata(), "debug_rnglists");
639   DwarfMacinfoSection = Ctx->getCOFFSection(
640       ".debug_macinfo",
641       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
642           COFF::IMAGE_SCN_MEM_READ,
643       SectionKind::getMetadata(), "debug_macinfo");
644   DwarfMacroSection = Ctx->getCOFFSection(
645       ".debug_macro",
646       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
647           COFF::IMAGE_SCN_MEM_READ,
648       SectionKind::getMetadata(), "debug_macro");
649   DwarfMacinfoDWOSection = Ctx->getCOFFSection(
650       ".debug_macinfo.dwo",
651       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
652           COFF::IMAGE_SCN_MEM_READ,
653       SectionKind::getMetadata(), "debug_macinfo.dwo");
654   DwarfMacroDWOSection = Ctx->getCOFFSection(
655       ".debug_macro.dwo",
656       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
657           COFF::IMAGE_SCN_MEM_READ,
658       SectionKind::getMetadata(), "debug_macro.dwo");
659   DwarfInfoDWOSection = Ctx->getCOFFSection(
660       ".debug_info.dwo",
661       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
662           COFF::IMAGE_SCN_MEM_READ,
663       SectionKind::getMetadata(), "section_info_dwo");
664   DwarfTypesDWOSection = Ctx->getCOFFSection(
665       ".debug_types.dwo",
666       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
667           COFF::IMAGE_SCN_MEM_READ,
668       SectionKind::getMetadata(), "section_types_dwo");
669   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
670       ".debug_abbrev.dwo",
671       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
672           COFF::IMAGE_SCN_MEM_READ,
673       SectionKind::getMetadata(), "section_abbrev_dwo");
674   DwarfStrDWOSection = Ctx->getCOFFSection(
675       ".debug_str.dwo",
676       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
677           COFF::IMAGE_SCN_MEM_READ,
678       SectionKind::getMetadata(), "skel_string");
679   DwarfLineDWOSection = Ctx->getCOFFSection(
680       ".debug_line.dwo",
681       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
682           COFF::IMAGE_SCN_MEM_READ,
683       SectionKind::getMetadata());
684   DwarfLocDWOSection = Ctx->getCOFFSection(
685       ".debug_loc.dwo",
686       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
687           COFF::IMAGE_SCN_MEM_READ,
688       SectionKind::getMetadata(), "skel_loc");
689   DwarfStrOffDWOSection = Ctx->getCOFFSection(
690       ".debug_str_offsets.dwo",
691       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
692           COFF::IMAGE_SCN_MEM_READ,
693       SectionKind::getMetadata(), "section_str_off_dwo");
694   DwarfAddrSection = Ctx->getCOFFSection(
695       ".debug_addr",
696       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
697           COFF::IMAGE_SCN_MEM_READ,
698       SectionKind::getMetadata(), "addr_sec");
699   DwarfCUIndexSection = Ctx->getCOFFSection(
700       ".debug_cu_index",
701       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
702           COFF::IMAGE_SCN_MEM_READ,
703       SectionKind::getMetadata());
704   DwarfTUIndexSection = Ctx->getCOFFSection(
705       ".debug_tu_index",
706       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
707           COFF::IMAGE_SCN_MEM_READ,
708       SectionKind::getMetadata());
709   DwarfDebugNamesSection = Ctx->getCOFFSection(
710       ".debug_names",
711       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
712           COFF::IMAGE_SCN_MEM_READ,
713       SectionKind::getMetadata(), "debug_names_begin");
714   DwarfAccelNamesSection = Ctx->getCOFFSection(
715       ".apple_names",
716       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
717           COFF::IMAGE_SCN_MEM_READ,
718       SectionKind::getMetadata(), "names_begin");
719   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
720       ".apple_namespaces",
721       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
722           COFF::IMAGE_SCN_MEM_READ,
723       SectionKind::getMetadata(), "namespac_begin");
724   DwarfAccelTypesSection = Ctx->getCOFFSection(
725       ".apple_types",
726       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
727           COFF::IMAGE_SCN_MEM_READ,
728       SectionKind::getMetadata(), "types_begin");
729   DwarfAccelObjCSection = Ctx->getCOFFSection(
730       ".apple_objc",
731       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
732           COFF::IMAGE_SCN_MEM_READ,
733       SectionKind::getMetadata(), "objc_begin");
734 
735   DrectveSection = Ctx->getCOFFSection(
736       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
737       SectionKind::getMetadata());
738 
739   PDataSection = Ctx->getCOFFSection(
740       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
741       SectionKind::getData());
742 
743   XDataSection = Ctx->getCOFFSection(
744       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
745       SectionKind::getData());
746 
747   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
748                                       SectionKind::getMetadata());
749 
750   GFIDsSection = Ctx->getCOFFSection(".gfids$y",
751                                      COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
752                                          COFF::IMAGE_SCN_MEM_READ,
753                                      SectionKind::getMetadata());
754 
755   GLJMPSection = Ctx->getCOFFSection(".gljmp$y",
756                                      COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
757                                          COFF::IMAGE_SCN_MEM_READ,
758                                      SectionKind::getMetadata());
759 
760   TLSDataSection = Ctx->getCOFFSection(
761       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
762                    COFF::IMAGE_SCN_MEM_WRITE,
763       SectionKind::getData());
764 
765   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
766                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
767                                             COFF::IMAGE_SCN_MEM_READ,
768                                         SectionKind::getReadOnly());
769 }
770 
771 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) {
772   TextSection = Ctx->getWasmSection(".text", SectionKind::getText());
773   DataSection = Ctx->getWasmSection(".data", SectionKind::getData());
774 
775   DwarfLineSection =
776       Ctx->getWasmSection(".debug_line", SectionKind::getMetadata());
777   DwarfLineStrSection =
778       Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata());
779   DwarfStrSection =
780       Ctx->getWasmSection(".debug_str", SectionKind::getMetadata());
781   DwarfLocSection =
782       Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata());
783   DwarfAbbrevSection =
784       Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata());
785   DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata());
786   DwarfRangesSection =
787       Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata());
788   DwarfMacinfoSection =
789       Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata());
790   DwarfMacroSection =
791       Ctx->getWasmSection(".debug_macro", SectionKind::getMetadata());
792   DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata());
793   DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata());
794   DwarfInfoSection =
795       Ctx->getWasmSection(".debug_info", SectionKind::getMetadata());
796   DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata());
797   DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata());
798   DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata());
799 
800   DwarfDebugNamesSection =
801       Ctx->getWasmSection(".debug_names", SectionKind::getMetadata());
802   DwarfStrOffSection =
803       Ctx->getWasmSection(".debug_str_offsets", SectionKind::getMetadata());
804   DwarfAddrSection =
805       Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata());
806   DwarfRnglistsSection =
807       Ctx->getWasmSection(".debug_rnglists", SectionKind::getMetadata());
808   DwarfLoclistsSection =
809       Ctx->getWasmSection(".debug_loclists", SectionKind::getMetadata());
810 
811   // Wasm use data section for LSDA.
812   // TODO Consider putting each function's exception table in a separate
813   // section, as in -function-sections, to facilitate lld's --gc-section.
814   LSDASection = Ctx->getWasmSection(".rodata.gcc_except_table",
815                                     SectionKind::getReadOnlyWithRel());
816 
817   // TODO: Define more sections.
818 }
819 
820 void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) {
821   // The default csect for program code. Functions without a specified section
822   // get placed into this csect. The choice of csect name is not a property of
823   // the ABI or object file format. For example, the XL compiler uses an unnamed
824   // csect for program code.
825   TextSection = Ctx->getXCOFFSection(
826       ".text", XCOFF::StorageMappingClass::XMC_PR, XCOFF::XTY_SD,
827       XCOFF::C_HIDEXT, SectionKind::getText());
828 
829   DataSection = Ctx->getXCOFFSection(
830       ".data", XCOFF::StorageMappingClass::XMC_RW, XCOFF::XTY_SD,
831       XCOFF::C_HIDEXT, SectionKind::getData());
832 
833   ReadOnlySection = Ctx->getXCOFFSection(
834       ".rodata", XCOFF::StorageMappingClass::XMC_RO, XCOFF::XTY_SD,
835       XCOFF::C_HIDEXT, SectionKind::getReadOnly());
836 
837   TOCBaseSection = Ctx->getXCOFFSection(
838       "TOC", XCOFF::StorageMappingClass::XMC_TC0, XCOFF::XTY_SD,
839       XCOFF::C_HIDEXT, SectionKind::getData());
840 
841   // The TOC-base always has 0 size, but 4 byte alignment.
842   TOCBaseSection->setAlignment(Align(4));
843 
844   // DWARF sections for XCOFF are not csects. They are special STYP_DWARF
845   // sections, and the individual DWARF sections are distinguished by their
846   // section subtype.
847   // TODO: Populate the DWARF sections appropriately.
848   DwarfAbbrevSection = nullptr;   // SSUBTYP_DWABREV
849   DwarfInfoSection = nullptr;     // SSUBTYP_DWINFO
850   DwarfLineSection = nullptr;     // SSUBTYP_DWLINE
851   DwarfFrameSection = nullptr;    // SSUBTYP_DWFRAME
852   DwarfPubNamesSection = nullptr; // SSUBTYP_DWPBNMS
853   DwarfPubTypesSection = nullptr; // SSUBTYP_DWPBTYP
854   DwarfStrSection = nullptr;      // SSUBTYP_DWSTR
855   DwarfLocSection = nullptr;      // SSUBTYP_DWLOC
856   DwarfARangesSection = nullptr;  // SSUBTYP_DWARNGE
857   DwarfRangesSection = nullptr;   // SSUBTYP_DWRNGES
858   DwarfMacinfoSection = nullptr;  // SSUBTYP_DWMAC
859 }
860 
861 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
862                                             MCContext &ctx,
863                                             bool LargeCodeModel) {
864   PositionIndependent = PIC;
865   Ctx = &ctx;
866 
867   // Common.
868   CommDirectiveSupportsAlignment = true;
869   SupportsWeakOmittedEHFrame = true;
870   SupportsCompactUnwindWithoutEHFrame = false;
871   OmitDwarfIfHaveCompactUnwind = false;
872 
873   FDECFIEncoding = dwarf::DW_EH_PE_absptr;
874 
875   CompactUnwindDwarfEHFrameOnly = 0;
876 
877   EHFrameSection = nullptr;             // Created on demand.
878   CompactUnwindSection = nullptr;       // Used only by selected targets.
879   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
880   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
881   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
882   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
883 
884   TT = TheTriple;
885 
886   switch (TT.getObjectFormat()) {
887   case Triple::MachO:
888     Env = IsMachO;
889     initMachOMCObjectFileInfo(TT);
890     break;
891   case Triple::COFF:
892     if (!TT.isOSWindows())
893       report_fatal_error(
894           "Cannot initialize MC for non-Windows COFF object files.");
895 
896     Env = IsCOFF;
897     initCOFFMCObjectFileInfo(TT);
898     break;
899   case Triple::ELF:
900     Env = IsELF;
901     initELFMCObjectFileInfo(TT, LargeCodeModel);
902     break;
903   case Triple::Wasm:
904     Env = IsWasm;
905     initWasmMCObjectFileInfo(TT);
906     break;
907   case Triple::XCOFF:
908     Env = IsXCOFF;
909     initXCOFFMCObjectFileInfo(TT);
910     break;
911   case Triple::UnknownObjectFormat:
912     report_fatal_error("Cannot initialize MC for unknown object file format.");
913     break;
914   }
915 }
916 
917 MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name,
918                                                    uint64_t Hash) const {
919   switch (TT.getObjectFormat()) {
920   case Triple::ELF:
921     return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0,
922                               utostr(Hash));
923   case Triple::MachO:
924   case Triple::COFF:
925   case Triple::Wasm:
926   case Triple::XCOFF:
927   case Triple::UnknownObjectFormat:
928     report_fatal_error("Cannot get DWARF comdat section for this object file "
929                        "format: not implemented.");
930     break;
931   }
932   llvm_unreachable("Unknown ObjectFormatType");
933 }
934 
935 MCSection *
936 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const {
937   if (Env != IsELF)
938     return StackSizesSection;
939 
940   const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec);
941   unsigned Flags = ELF::SHF_LINK_ORDER;
942   StringRef GroupName;
943   if (const MCSymbol *Group = ElfSec.getGroup()) {
944     GroupName = Group->getName();
945     Flags |= ELF::SHF_GROUP;
946   }
947 
948   return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0,
949                             GroupName, MCSection::NonUniqueID,
950                             cast<MCSymbolELF>(TextSec.getBeginSymbol()));
951 }
952