xref: /llvm-project/llvm/lib/MC/MCObjectFileInfo.cpp (revision ce95ac64908082abf27cbc23683c1cca0c6719f1)
1 //===-- MCObjectFileInfo.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/BinaryFormat/COFF.h"
14 #include "llvm/BinaryFormat/ELF.h"
15 #include "llvm/MC/MCAsmInfo.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCSection.h"
18 #include "llvm/MC/MCSectionCOFF.h"
19 #include "llvm/MC/MCSectionELF.h"
20 #include "llvm/MC/MCSectionMachO.h"
21 #include "llvm/MC/MCSectionWasm.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   DwarfLocSection =
258       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
259                            SectionKind::getMetadata(), "section_debug_loc");
260   DwarfARangesSection =
261       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
262                            SectionKind::getMetadata());
263   DwarfRangesSection =
264       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
265                            SectionKind::getMetadata(), "debug_range");
266   DwarfRnglistsSection =
267       Ctx->getMachOSection("__DWARF", "__debug_rnglists", MachO::S_ATTR_DEBUG,
268                            SectionKind::getMetadata(), "debug_range");
269   DwarfMacinfoSection =
270       Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG,
271                            SectionKind::getMetadata(), "debug_macinfo");
272   DwarfDebugInlineSection =
273       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
274                            SectionKind::getMetadata());
275   DwarfCUIndexSection =
276       Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
277                            SectionKind::getMetadata());
278   DwarfTUIndexSection =
279       Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG,
280                            SectionKind::getMetadata());
281   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
282                                          0, SectionKind::getMetadata());
283 
284   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
285                                          0, SectionKind::getMetadata());
286 
287   TLSExtraDataSection = TLSTLVSection;
288 }
289 
290 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
291   switch (T.getArch()) {
292   case Triple::mips:
293   case Triple::mipsel:
294     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
295     break;
296   case Triple::mips64:
297   case Triple::mips64el:
298     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
299     break;
300   case Triple::ppc64:
301   case Triple::ppc64le:
302   case Triple::x86_64:
303     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
304                      (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
305     break;
306   case Triple::bpfel:
307   case Triple::bpfeb:
308     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
309     break;
310   case Triple::hexagon:
311     FDECFIEncoding =
312         PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr;
313     break;
314   default:
315     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
316     break;
317   }
318 
319   unsigned EHSectionType = T.getArch() == Triple::x86_64
320                                ? ELF::SHT_X86_64_UNWIND
321                                : ELF::SHT_PROGBITS;
322 
323   // Solaris requires different flags for .eh_frame to seemingly every other
324   // platform.
325   unsigned EHSectionFlags = ELF::SHF_ALLOC;
326   if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
327     EHSectionFlags |= ELF::SHF_WRITE;
328 
329   // ELF
330   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
331                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
332 
333   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
334                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
335 
336   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
337                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
338 
339   ReadOnlySection =
340       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
341 
342   TLSDataSection =
343       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
344                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
345 
346   TLSBSSSection = Ctx->getELFSection(
347       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
348 
349   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
350                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
351 
352   MergeableConst4Section =
353       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
354                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
355 
356   MergeableConst8Section =
357       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
358                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
359 
360   MergeableConst16Section =
361       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
362                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
363 
364   MergeableConst32Section =
365       Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
366                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
367 
368   // Exception Handling Sections.
369 
370   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
371   // it contains relocatable pointers.  In PIC mode, this is probably a big
372   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
373   // adjusted or this should be a data section.
374   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
375                                    ELF::SHF_ALLOC);
376 
377   COFFDebugSymbolsSection = nullptr;
378   COFFDebugTypesSection = nullptr;
379 
380   unsigned DebugSecType = ELF::SHT_PROGBITS;
381 
382   // MIPS .debug_* sections should have SHT_MIPS_DWARF section type
383   // to distinguish among sections contain DWARF and ECOFF debug formats.
384   // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS.
385   if (T.isMIPS())
386     DebugSecType = ELF::SHT_MIPS_DWARF;
387 
388   // Debug Info Sections.
389   DwarfAbbrevSection =
390       Ctx->getELFSection(".debug_abbrev", DebugSecType, 0);
391   DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0);
392   DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0);
393   DwarfLineStrSection =
394       Ctx->getELFSection(".debug_line_str", DebugSecType,
395                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
396   DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0);
397   DwarfPubNamesSection =
398       Ctx->getELFSection(".debug_pubnames", DebugSecType, 0);
399   DwarfPubTypesSection =
400       Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0);
401   DwarfGnuPubNamesSection =
402       Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0);
403   DwarfGnuPubTypesSection =
404       Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0);
405   DwarfStrSection =
406       Ctx->getELFSection(".debug_str", DebugSecType,
407                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
408   DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0);
409   DwarfARangesSection =
410       Ctx->getELFSection(".debug_aranges", DebugSecType, 0);
411   DwarfRangesSection =
412       Ctx->getELFSection(".debug_ranges", DebugSecType, 0);
413   DwarfMacinfoSection =
414       Ctx->getELFSection(".debug_macinfo", DebugSecType, 0);
415 
416   // DWARF5 Experimental Debug Info
417 
418   // Accelerator Tables
419   DwarfDebugNamesSection =
420       Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0);
421   DwarfAccelNamesSection =
422       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
423   DwarfAccelObjCSection =
424       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
425   DwarfAccelNamespaceSection =
426       Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
427   DwarfAccelTypesSection =
428       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
429 
430   // String Offset and Address Sections
431   DwarfStrOffSection =
432       Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0);
433   DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0);
434   DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0);
435 
436   // Fission Sections
437   DwarfInfoDWOSection =
438       Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE);
439   DwarfTypesDWOSection =
440       Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE);
441   DwarfAbbrevDWOSection =
442       Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE);
443   DwarfStrDWOSection = Ctx->getELFSection(
444       ".debug_str.dwo", DebugSecType,
445       ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, "");
446   DwarfLineDWOSection =
447       Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE);
448   DwarfLocDWOSection =
449       Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE);
450   DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo",
451                                              DebugSecType, ELF::SHF_EXCLUDE);
452   DwarfRnglistsDWOSection =
453       Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE);
454 
455   // DWP Sections
456   DwarfCUIndexSection =
457       Ctx->getELFSection(".debug_cu_index", DebugSecType, 0);
458   DwarfTUIndexSection =
459       Ctx->getELFSection(".debug_tu_index", DebugSecType, 0);
460 
461   StackMapSection =
462       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
463 
464   FaultMapSection =
465       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
466 
467   EHFrameSection =
468       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
469 
470   StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0);
471 }
472 
473 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
474   EHFrameSection = Ctx->getCOFFSection(
475       ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
476                        COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
477       SectionKind::getData());
478 
479   // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode.  This is
480   // used to indicate to the linker that the text segment contains thumb instructions
481   // and to set the ISA selection bit for calls accordingly.
482   const bool IsThumb = T.getArch() == Triple::thumb;
483 
484   CommDirectiveSupportsAlignment = true;
485 
486   // COFF
487   BSSSection = Ctx->getCOFFSection(
488       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
489                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
490       SectionKind::getBSS());
491   TextSection = Ctx->getCOFFSection(
492       ".text",
493       (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
494           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
495           COFF::IMAGE_SCN_MEM_READ,
496       SectionKind::getText());
497   DataSection = Ctx->getCOFFSection(
498       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
499                    COFF::IMAGE_SCN_MEM_WRITE,
500       SectionKind::getData());
501   ReadOnlySection = Ctx->getCOFFSection(
502       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
503       SectionKind::getReadOnly());
504 
505   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
506   // though it contains relocatable pointers.  In PIC mode, this is probably a
507   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
508   // adjusted or this should be a data section.
509   if (T.getArch() == Triple::x86_64) {
510     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
511     LSDASection = nullptr;
512   } else {
513     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
514                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
515                                           COFF::IMAGE_SCN_MEM_READ,
516                                       SectionKind::getReadOnly());
517   }
518 
519   // Debug info.
520   COFFDebugSymbolsSection =
521       Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
522                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
523                                        COFF::IMAGE_SCN_MEM_READ),
524                           SectionKind::getMetadata());
525   COFFDebugTypesSection =
526       Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
527                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
528                                        COFF::IMAGE_SCN_MEM_READ),
529                           SectionKind::getMetadata());
530   COFFGlobalTypeHashesSection = Ctx->getCOFFSection(
531       ".debug$H",
532       (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
533        COFF::IMAGE_SCN_MEM_READ),
534       SectionKind::getMetadata());
535 
536   DwarfAbbrevSection = Ctx->getCOFFSection(
537       ".debug_abbrev",
538       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
539           COFF::IMAGE_SCN_MEM_READ,
540       SectionKind::getMetadata(), "section_abbrev");
541   DwarfInfoSection = Ctx->getCOFFSection(
542       ".debug_info",
543       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
544           COFF::IMAGE_SCN_MEM_READ,
545       SectionKind::getMetadata(), "section_info");
546   DwarfLineSection = Ctx->getCOFFSection(
547       ".debug_line",
548       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
549           COFF::IMAGE_SCN_MEM_READ,
550       SectionKind::getMetadata(), "section_line");
551   DwarfLineStrSection = Ctx->getCOFFSection(
552       ".debug_line_str",
553       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
554           COFF::IMAGE_SCN_MEM_READ,
555       SectionKind::getMetadata(), "section_line_str");
556   DwarfFrameSection = Ctx->getCOFFSection(
557       ".debug_frame",
558       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
559           COFF::IMAGE_SCN_MEM_READ,
560       SectionKind::getMetadata());
561   DwarfPubNamesSection = Ctx->getCOFFSection(
562       ".debug_pubnames",
563       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
564           COFF::IMAGE_SCN_MEM_READ,
565       SectionKind::getMetadata());
566   DwarfPubTypesSection = Ctx->getCOFFSection(
567       ".debug_pubtypes",
568       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
569           COFF::IMAGE_SCN_MEM_READ,
570       SectionKind::getMetadata());
571   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
572       ".debug_gnu_pubnames",
573       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
574           COFF::IMAGE_SCN_MEM_READ,
575       SectionKind::getMetadata());
576   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
577       ".debug_gnu_pubtypes",
578       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
579           COFF::IMAGE_SCN_MEM_READ,
580       SectionKind::getMetadata());
581   DwarfStrSection = Ctx->getCOFFSection(
582       ".debug_str",
583       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
584           COFF::IMAGE_SCN_MEM_READ,
585       SectionKind::getMetadata(), "info_string");
586   DwarfStrOffSection = Ctx->getCOFFSection(
587       ".debug_str_offsets",
588       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
589           COFF::IMAGE_SCN_MEM_READ,
590       SectionKind::getMetadata(), "section_str_off");
591   DwarfLocSection = Ctx->getCOFFSection(
592       ".debug_loc",
593       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
594           COFF::IMAGE_SCN_MEM_READ,
595       SectionKind::getMetadata(), "section_debug_loc");
596   DwarfARangesSection = Ctx->getCOFFSection(
597       ".debug_aranges",
598       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
599           COFF::IMAGE_SCN_MEM_READ,
600       SectionKind::getMetadata());
601   DwarfRangesSection = Ctx->getCOFFSection(
602       ".debug_ranges",
603       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
604           COFF::IMAGE_SCN_MEM_READ,
605       SectionKind::getMetadata(), "debug_range");
606   DwarfMacinfoSection = Ctx->getCOFFSection(
607       ".debug_macinfo",
608       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
609           COFF::IMAGE_SCN_MEM_READ,
610       SectionKind::getMetadata(), "debug_macinfo");
611   DwarfInfoDWOSection = Ctx->getCOFFSection(
612       ".debug_info.dwo",
613       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
614           COFF::IMAGE_SCN_MEM_READ,
615       SectionKind::getMetadata(), "section_info_dwo");
616   DwarfTypesDWOSection = Ctx->getCOFFSection(
617       ".debug_types.dwo",
618       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
619           COFF::IMAGE_SCN_MEM_READ,
620       SectionKind::getMetadata(), "section_types_dwo");
621   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
622       ".debug_abbrev.dwo",
623       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
624           COFF::IMAGE_SCN_MEM_READ,
625       SectionKind::getMetadata(), "section_abbrev_dwo");
626   DwarfStrDWOSection = Ctx->getCOFFSection(
627       ".debug_str.dwo",
628       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
629           COFF::IMAGE_SCN_MEM_READ,
630       SectionKind::getMetadata(), "skel_string");
631   DwarfLineDWOSection = Ctx->getCOFFSection(
632       ".debug_line.dwo",
633       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
634           COFF::IMAGE_SCN_MEM_READ,
635       SectionKind::getMetadata());
636   DwarfLocDWOSection = Ctx->getCOFFSection(
637       ".debug_loc.dwo",
638       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
639           COFF::IMAGE_SCN_MEM_READ,
640       SectionKind::getMetadata(), "skel_loc");
641   DwarfStrOffDWOSection = Ctx->getCOFFSection(
642       ".debug_str_offsets.dwo",
643       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
644           COFF::IMAGE_SCN_MEM_READ,
645       SectionKind::getMetadata(), "section_str_off_dwo");
646   DwarfAddrSection = Ctx->getCOFFSection(
647       ".debug_addr",
648       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
649           COFF::IMAGE_SCN_MEM_READ,
650       SectionKind::getMetadata(), "addr_sec");
651   DwarfCUIndexSection = Ctx->getCOFFSection(
652       ".debug_cu_index",
653       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
654           COFF::IMAGE_SCN_MEM_READ,
655       SectionKind::getMetadata());
656   DwarfTUIndexSection = Ctx->getCOFFSection(
657       ".debug_tu_index",
658       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
659           COFF::IMAGE_SCN_MEM_READ,
660       SectionKind::getMetadata());
661   DwarfDebugNamesSection = Ctx->getCOFFSection(
662       ".debug_names",
663       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
664           COFF::IMAGE_SCN_MEM_READ,
665       SectionKind::getMetadata(), "debug_names_begin");
666   DwarfAccelNamesSection = Ctx->getCOFFSection(
667       ".apple_names",
668       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
669           COFF::IMAGE_SCN_MEM_READ,
670       SectionKind::getMetadata(), "names_begin");
671   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
672       ".apple_namespaces",
673       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
674           COFF::IMAGE_SCN_MEM_READ,
675       SectionKind::getMetadata(), "namespac_begin");
676   DwarfAccelTypesSection = Ctx->getCOFFSection(
677       ".apple_types",
678       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
679           COFF::IMAGE_SCN_MEM_READ,
680       SectionKind::getMetadata(), "types_begin");
681   DwarfAccelObjCSection = Ctx->getCOFFSection(
682       ".apple_objc",
683       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
684           COFF::IMAGE_SCN_MEM_READ,
685       SectionKind::getMetadata(), "objc_begin");
686 
687   DrectveSection = Ctx->getCOFFSection(
688       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
689       SectionKind::getMetadata());
690 
691   PDataSection = Ctx->getCOFFSection(
692       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
693       SectionKind::getData());
694 
695   XDataSection = Ctx->getCOFFSection(
696       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
697       SectionKind::getData());
698 
699   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
700                                       SectionKind::getMetadata());
701 
702   GFIDsSection = Ctx->getCOFFSection(".gfids$y",
703                                      COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
704                                          COFF::IMAGE_SCN_MEM_READ,
705                                      SectionKind::getMetadata());
706 
707   TLSDataSection = Ctx->getCOFFSection(
708       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
709                    COFF::IMAGE_SCN_MEM_WRITE,
710       SectionKind::getData());
711 
712   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
713                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
714                                             COFF::IMAGE_SCN_MEM_READ,
715                                         SectionKind::getReadOnly());
716 }
717 
718 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) {
719   TextSection = Ctx->getWasmSection(".text", SectionKind::getText());
720   DataSection = Ctx->getWasmSection(".data", SectionKind::getData());
721 
722   DwarfLineSection =
723       Ctx->getWasmSection(".debug_line", SectionKind::getMetadata());
724   DwarfLineStrSection =
725       Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata());
726   DwarfStrSection =
727       Ctx->getWasmSection(".debug_str", SectionKind::getMetadata());
728   DwarfLocSection =
729       Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata());
730   DwarfAbbrevSection =
731       Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata());
732   DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata());
733   DwarfRangesSection =
734       Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata());
735   DwarfMacinfoSection =
736       Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata());
737   DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata());
738   DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata());
739   DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata());
740   DwarfInfoSection =
741       Ctx->getWasmSection(".debug_info", SectionKind::getMetadata());
742   DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata());
743   DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata());
744   DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata());
745 
746   // TODO: Define more sections.
747 }
748 
749 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
750                                             MCContext &ctx,
751                                             bool LargeCodeModel) {
752   PositionIndependent = PIC;
753   Ctx = &ctx;
754 
755   // Common.
756   CommDirectiveSupportsAlignment = true;
757   SupportsWeakOmittedEHFrame = true;
758   SupportsCompactUnwindWithoutEHFrame = false;
759   OmitDwarfIfHaveCompactUnwind = false;
760 
761   FDECFIEncoding = dwarf::DW_EH_PE_absptr;
762 
763   CompactUnwindDwarfEHFrameOnly = 0;
764 
765   EHFrameSection = nullptr;             // Created on demand.
766   CompactUnwindSection = nullptr;       // Used only by selected targets.
767   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
768   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
769   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
770   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
771 
772   TT = TheTriple;
773 
774   switch (TT.getObjectFormat()) {
775   case Triple::MachO:
776     Env = IsMachO;
777     initMachOMCObjectFileInfo(TT);
778     break;
779   case Triple::COFF:
780     if (!TT.isOSWindows())
781       report_fatal_error(
782           "Cannot initialize MC for non-Windows COFF object files.");
783 
784     Env = IsCOFF;
785     initCOFFMCObjectFileInfo(TT);
786     break;
787   case Triple::ELF:
788     Env = IsELF;
789     initELFMCObjectFileInfo(TT, LargeCodeModel);
790     break;
791   case Triple::Wasm:
792     Env = IsWasm;
793     initWasmMCObjectFileInfo(TT);
794     break;
795   case Triple::UnknownObjectFormat:
796     report_fatal_error("Cannot initialize MC for unknown object file format.");
797     break;
798   }
799 }
800 
801 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
802   switch (TT.getObjectFormat()) {
803   case Triple::ELF:
804     return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
805                               0, utostr(Hash));
806   case Triple::MachO:
807   case Triple::COFF:
808   case Triple::Wasm:
809   case Triple::UnknownObjectFormat:
810     report_fatal_error("Cannot get DWARF types section for this object file "
811                        "format: not implemented.");
812     break;
813   }
814   llvm_unreachable("Unknown ObjectFormatType");
815 }
816 
817 MCSection *
818 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const {
819   if (Env != IsELF)
820     return StackSizesSection;
821 
822   const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec);
823   unsigned Flags = ELF::SHF_LINK_ORDER;
824   StringRef GroupName;
825   if (const MCSymbol *Group = ElfSec.getGroup()) {
826     GroupName = Group->getName();
827     Flags |= ELF::SHF_GROUP;
828   }
829 
830   const MCSymbol *Link = TextSec.getBeginSymbol();
831   auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()});
832   unsigned UniqueID = It.first->second;
833 
834   return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0,
835                             GroupName, UniqueID, cast<MCSymbolELF>(Link));
836 }
837