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
useCompactUnwind(const Triple & T)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
initMachOMCObjectFileInfo(const Triple & T)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 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
initELFMCObjectFileInfo(const Triple & T,bool Large)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 // We cannot use DW_EH_PE_sdata8 for the large PositionIndependent case
307 // since there is no R_MIPS_PC64 relocation (only a 32-bit version).
308 if (PositionIndependent && !Large)
309 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
310 else
311 FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4
312 ? dwarf::DW_EH_PE_sdata4
313 : dwarf::DW_EH_PE_sdata8;
314 break;
315 case Triple::ppc64:
316 case Triple::ppc64le:
317 case Triple::x86_64:
318 FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
319 (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
320 break;
321 case Triple::bpfel:
322 case Triple::bpfeb:
323 FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
324 break;
325 case Triple::hexagon:
326 FDECFIEncoding =
327 PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr;
328 break;
329 default:
330 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
331 break;
332 }
333
334 unsigned EHSectionType = T.getArch() == Triple::x86_64
335 ? ELF::SHT_X86_64_UNWIND
336 : ELF::SHT_PROGBITS;
337
338 // Solaris requires different flags for .eh_frame to seemingly every other
339 // platform.
340 unsigned EHSectionFlags = ELF::SHF_ALLOC;
341 if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
342 EHSectionFlags |= ELF::SHF_WRITE;
343
344 // ELF
345 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
346 ELF::SHF_WRITE | ELF::SHF_ALLOC);
347
348 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
349 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
350
351 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
352 ELF::SHF_WRITE | ELF::SHF_ALLOC);
353
354 ReadOnlySection =
355 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
356
357 TLSDataSection =
358 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
359 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
360
361 TLSBSSSection = Ctx->getELFSection(
362 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
363
364 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
365 ELF::SHF_ALLOC | ELF::SHF_WRITE);
366
367 MergeableConst4Section =
368 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
369 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
370
371 MergeableConst8Section =
372 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
373 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
374
375 MergeableConst16Section =
376 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
377 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
378
379 MergeableConst32Section =
380 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
381 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
382
383 // Exception Handling Sections.
384
385 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
386 // it contains relocatable pointers. In PIC mode, this is probably a big
387 // runtime hit for C++ apps. Either the contents of the LSDA need to be
388 // adjusted or this should be a data section.
389 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
390 ELF::SHF_ALLOC);
391
392 COFFDebugSymbolsSection = nullptr;
393 COFFDebugTypesSection = nullptr;
394
395 unsigned DebugSecType = ELF::SHT_PROGBITS;
396
397 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type
398 // to distinguish among sections contain DWARF and ECOFF debug formats.
399 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS.
400 if (T.isMIPS())
401 DebugSecType = ELF::SHT_MIPS_DWARF;
402
403 // Debug Info Sections.
404 DwarfAbbrevSection =
405 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0);
406 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0);
407 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0);
408 DwarfLineStrSection =
409 Ctx->getELFSection(".debug_line_str", DebugSecType,
410 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
411 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0);
412 DwarfPubNamesSection =
413 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0);
414 DwarfPubTypesSection =
415 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0);
416 DwarfGnuPubNamesSection =
417 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0);
418 DwarfGnuPubTypesSection =
419 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0);
420 DwarfStrSection =
421 Ctx->getELFSection(".debug_str", DebugSecType,
422 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
423 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0);
424 DwarfARangesSection =
425 Ctx->getELFSection(".debug_aranges", DebugSecType, 0);
426 DwarfRangesSection =
427 Ctx->getELFSection(".debug_ranges", DebugSecType, 0);
428 DwarfMacinfoSection =
429 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0);
430
431 // DWARF5 Experimental Debug Info
432
433 // Accelerator Tables
434 DwarfDebugNamesSection =
435 Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0);
436 DwarfAccelNamesSection =
437 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
438 DwarfAccelObjCSection =
439 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
440 DwarfAccelNamespaceSection =
441 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
442 DwarfAccelTypesSection =
443 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
444
445 // String Offset and Address Sections
446 DwarfStrOffSection =
447 Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0);
448 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0);
449 DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0);
450 DwarfLoclistsSection = Ctx->getELFSection(".debug_loclists", DebugSecType, 0);
451
452 // Fission Sections
453 DwarfInfoDWOSection =
454 Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE);
455 DwarfTypesDWOSection =
456 Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE);
457 DwarfAbbrevDWOSection =
458 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE);
459 DwarfStrDWOSection = Ctx->getELFSection(
460 ".debug_str.dwo", DebugSecType,
461 ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, "");
462 DwarfLineDWOSection =
463 Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE);
464 DwarfLocDWOSection =
465 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE);
466 DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo",
467 DebugSecType, ELF::SHF_EXCLUDE);
468 DwarfRnglistsDWOSection =
469 Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE);
470 DwarfMacinfoDWOSection =
471 Ctx->getELFSection(".debug_macinfo.dwo", DebugSecType, ELF::SHF_EXCLUDE);
472
473 DwarfLoclistsDWOSection =
474 Ctx->getELFSection(".debug_loclists.dwo", DebugSecType, ELF::SHF_EXCLUDE);
475
476 // DWP Sections
477 DwarfCUIndexSection =
478 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0);
479 DwarfTUIndexSection =
480 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0);
481
482 StackMapSection =
483 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
484
485 FaultMapSection =
486 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
487
488 EHFrameSection =
489 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
490
491 StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0);
492 }
493
initCOFFMCObjectFileInfo(const Triple & T)494 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
495 EHFrameSection =
496 Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
497 COFF::IMAGE_SCN_MEM_READ,
498 SectionKind::getData());
499
500 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is
501 // used to indicate to the linker that the text segment contains thumb instructions
502 // and to set the ISA selection bit for calls accordingly.
503 const bool IsThumb = T.getArch() == Triple::thumb;
504
505 CommDirectiveSupportsAlignment = true;
506
507 // COFF
508 BSSSection = Ctx->getCOFFSection(
509 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
510 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
511 SectionKind::getBSS());
512 TextSection = Ctx->getCOFFSection(
513 ".text",
514 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
515 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
516 COFF::IMAGE_SCN_MEM_READ,
517 SectionKind::getText());
518 DataSection = Ctx->getCOFFSection(
519 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
520 COFF::IMAGE_SCN_MEM_WRITE,
521 SectionKind::getData());
522 ReadOnlySection = Ctx->getCOFFSection(
523 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
524 SectionKind::getReadOnly());
525
526 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::aarch64) {
527 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
528 LSDASection = nullptr;
529 } else {
530 LSDASection = Ctx->getCOFFSection(".gcc_except_table",
531 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
532 COFF::IMAGE_SCN_MEM_READ,
533 SectionKind::getReadOnly());
534 }
535
536 // Debug info.
537 COFFDebugSymbolsSection =
538 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
539 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
540 COFF::IMAGE_SCN_MEM_READ),
541 SectionKind::getMetadata());
542 COFFDebugTypesSection =
543 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
544 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
545 COFF::IMAGE_SCN_MEM_READ),
546 SectionKind::getMetadata());
547 COFFGlobalTypeHashesSection = Ctx->getCOFFSection(
548 ".debug$H",
549 (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
550 COFF::IMAGE_SCN_MEM_READ),
551 SectionKind::getMetadata());
552
553 DwarfAbbrevSection = Ctx->getCOFFSection(
554 ".debug_abbrev",
555 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
556 COFF::IMAGE_SCN_MEM_READ,
557 SectionKind::getMetadata(), "section_abbrev");
558 DwarfInfoSection = Ctx->getCOFFSection(
559 ".debug_info",
560 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
561 COFF::IMAGE_SCN_MEM_READ,
562 SectionKind::getMetadata(), "section_info");
563 DwarfLineSection = Ctx->getCOFFSection(
564 ".debug_line",
565 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
566 COFF::IMAGE_SCN_MEM_READ,
567 SectionKind::getMetadata(), "section_line");
568 DwarfLineStrSection = Ctx->getCOFFSection(
569 ".debug_line_str",
570 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
571 COFF::IMAGE_SCN_MEM_READ,
572 SectionKind::getMetadata(), "section_line_str");
573 DwarfFrameSection = Ctx->getCOFFSection(
574 ".debug_frame",
575 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
576 COFF::IMAGE_SCN_MEM_READ,
577 SectionKind::getMetadata());
578 DwarfPubNamesSection = Ctx->getCOFFSection(
579 ".debug_pubnames",
580 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
581 COFF::IMAGE_SCN_MEM_READ,
582 SectionKind::getMetadata());
583 DwarfPubTypesSection = Ctx->getCOFFSection(
584 ".debug_pubtypes",
585 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
586 COFF::IMAGE_SCN_MEM_READ,
587 SectionKind::getMetadata());
588 DwarfGnuPubNamesSection = Ctx->getCOFFSection(
589 ".debug_gnu_pubnames",
590 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
591 COFF::IMAGE_SCN_MEM_READ,
592 SectionKind::getMetadata());
593 DwarfGnuPubTypesSection = Ctx->getCOFFSection(
594 ".debug_gnu_pubtypes",
595 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
596 COFF::IMAGE_SCN_MEM_READ,
597 SectionKind::getMetadata());
598 DwarfStrSection = Ctx->getCOFFSection(
599 ".debug_str",
600 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
601 COFF::IMAGE_SCN_MEM_READ,
602 SectionKind::getMetadata(), "info_string");
603 DwarfStrOffSection = Ctx->getCOFFSection(
604 ".debug_str_offsets",
605 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
606 COFF::IMAGE_SCN_MEM_READ,
607 SectionKind::getMetadata(), "section_str_off");
608 DwarfLocSection = Ctx->getCOFFSection(
609 ".debug_loc",
610 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
611 COFF::IMAGE_SCN_MEM_READ,
612 SectionKind::getMetadata(), "section_debug_loc");
613 DwarfARangesSection = Ctx->getCOFFSection(
614 ".debug_aranges",
615 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
616 COFF::IMAGE_SCN_MEM_READ,
617 SectionKind::getMetadata());
618 DwarfRangesSection = Ctx->getCOFFSection(
619 ".debug_ranges",
620 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
621 COFF::IMAGE_SCN_MEM_READ,
622 SectionKind::getMetadata(), "debug_range");
623 DwarfMacinfoSection = Ctx->getCOFFSection(
624 ".debug_macinfo",
625 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
626 COFF::IMAGE_SCN_MEM_READ,
627 SectionKind::getMetadata(), "debug_macinfo");
628 DwarfMacinfoDWOSection = Ctx->getCOFFSection(
629 ".debug_macinfo.dwo",
630 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
631 COFF::IMAGE_SCN_MEM_READ,
632 SectionKind::getMetadata(), "debug_macinfo.dwo");
633 DwarfInfoDWOSection = Ctx->getCOFFSection(
634 ".debug_info.dwo",
635 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
636 COFF::IMAGE_SCN_MEM_READ,
637 SectionKind::getMetadata(), "section_info_dwo");
638 DwarfTypesDWOSection = Ctx->getCOFFSection(
639 ".debug_types.dwo",
640 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
641 COFF::IMAGE_SCN_MEM_READ,
642 SectionKind::getMetadata(), "section_types_dwo");
643 DwarfAbbrevDWOSection = Ctx->getCOFFSection(
644 ".debug_abbrev.dwo",
645 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
646 COFF::IMAGE_SCN_MEM_READ,
647 SectionKind::getMetadata(), "section_abbrev_dwo");
648 DwarfStrDWOSection = Ctx->getCOFFSection(
649 ".debug_str.dwo",
650 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
651 COFF::IMAGE_SCN_MEM_READ,
652 SectionKind::getMetadata(), "skel_string");
653 DwarfLineDWOSection = Ctx->getCOFFSection(
654 ".debug_line.dwo",
655 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
656 COFF::IMAGE_SCN_MEM_READ,
657 SectionKind::getMetadata());
658 DwarfLocDWOSection = Ctx->getCOFFSection(
659 ".debug_loc.dwo",
660 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
661 COFF::IMAGE_SCN_MEM_READ,
662 SectionKind::getMetadata(), "skel_loc");
663 DwarfStrOffDWOSection = Ctx->getCOFFSection(
664 ".debug_str_offsets.dwo",
665 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
666 COFF::IMAGE_SCN_MEM_READ,
667 SectionKind::getMetadata(), "section_str_off_dwo");
668 DwarfAddrSection = Ctx->getCOFFSection(
669 ".debug_addr",
670 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
671 COFF::IMAGE_SCN_MEM_READ,
672 SectionKind::getMetadata(), "addr_sec");
673 DwarfCUIndexSection = Ctx->getCOFFSection(
674 ".debug_cu_index",
675 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
676 COFF::IMAGE_SCN_MEM_READ,
677 SectionKind::getMetadata());
678 DwarfTUIndexSection = Ctx->getCOFFSection(
679 ".debug_tu_index",
680 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
681 COFF::IMAGE_SCN_MEM_READ,
682 SectionKind::getMetadata());
683 DwarfDebugNamesSection = Ctx->getCOFFSection(
684 ".debug_names",
685 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
686 COFF::IMAGE_SCN_MEM_READ,
687 SectionKind::getMetadata(), "debug_names_begin");
688 DwarfAccelNamesSection = Ctx->getCOFFSection(
689 ".apple_names",
690 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
691 COFF::IMAGE_SCN_MEM_READ,
692 SectionKind::getMetadata(), "names_begin");
693 DwarfAccelNamespaceSection = Ctx->getCOFFSection(
694 ".apple_namespaces",
695 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
696 COFF::IMAGE_SCN_MEM_READ,
697 SectionKind::getMetadata(), "namespac_begin");
698 DwarfAccelTypesSection = Ctx->getCOFFSection(
699 ".apple_types",
700 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
701 COFF::IMAGE_SCN_MEM_READ,
702 SectionKind::getMetadata(), "types_begin");
703 DwarfAccelObjCSection = Ctx->getCOFFSection(
704 ".apple_objc",
705 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
706 COFF::IMAGE_SCN_MEM_READ,
707 SectionKind::getMetadata(), "objc_begin");
708
709 DrectveSection = Ctx->getCOFFSection(
710 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
711 SectionKind::getMetadata());
712
713 PDataSection = Ctx->getCOFFSection(
714 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
715 SectionKind::getData());
716
717 XDataSection = Ctx->getCOFFSection(
718 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
719 SectionKind::getData());
720
721 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
722 SectionKind::getMetadata());
723
724 GFIDsSection = Ctx->getCOFFSection(".gfids$y",
725 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
726 COFF::IMAGE_SCN_MEM_READ,
727 SectionKind::getMetadata());
728
729 GLJMPSection = Ctx->getCOFFSection(".gljmp$y",
730 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
731 COFF::IMAGE_SCN_MEM_READ,
732 SectionKind::getMetadata());
733
734 TLSDataSection = Ctx->getCOFFSection(
735 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
736 COFF::IMAGE_SCN_MEM_WRITE,
737 SectionKind::getData());
738
739 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
740 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
741 COFF::IMAGE_SCN_MEM_READ,
742 SectionKind::getReadOnly());
743 }
744
initWasmMCObjectFileInfo(const Triple & T)745 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) {
746 TextSection = Ctx->getWasmSection(".text", SectionKind::getText());
747 DataSection = Ctx->getWasmSection(".data", SectionKind::getData());
748
749 DwarfLineSection =
750 Ctx->getWasmSection(".debug_line", SectionKind::getMetadata());
751 DwarfLineStrSection =
752 Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata());
753 DwarfStrSection =
754 Ctx->getWasmSection(".debug_str", SectionKind::getMetadata());
755 DwarfLocSection =
756 Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata());
757 DwarfAbbrevSection =
758 Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata());
759 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata());
760 DwarfRangesSection =
761 Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata());
762 DwarfMacinfoSection =
763 Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata());
764 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata());
765 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata());
766 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata());
767 DwarfInfoSection =
768 Ctx->getWasmSection(".debug_info", SectionKind::getMetadata());
769 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata());
770 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata());
771 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata());
772
773 // Wasm use data section for LSDA.
774 // TODO Consider putting each function's exception table in a separate
775 // section, as in -function-sections, to facilitate lld's --gc-section.
776 LSDASection = Ctx->getWasmSection(".rodata.gcc_except_table",
777 SectionKind::getReadOnlyWithRel());
778
779 // TODO: Define more sections.
780 }
781
initXCOFFMCObjectFileInfo(const Triple & T)782 void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) {
783 // The default csect for program code. Functions without a specified section
784 // get placed into this csect. The choice of csect name is not a property of
785 // the ABI or object file format. For example, the XL compiler uses an unnamed
786 // csect for program code.
787 TextSection = Ctx->getXCOFFSection(
788 ".text", XCOFF::StorageMappingClass::XMC_PR, XCOFF::XTY_SD,
789 XCOFF::C_HIDEXT, SectionKind::getText());
790
791 DataSection = Ctx->getXCOFFSection(
792 ".data", XCOFF::StorageMappingClass::XMC_RW, XCOFF::XTY_SD,
793 XCOFF::C_HIDEXT, SectionKind::getData());
794
795 ReadOnlySection = Ctx->getXCOFFSection(
796 ".rodata", XCOFF::StorageMappingClass::XMC_RO, XCOFF::XTY_SD,
797 XCOFF::C_HIDEXT, SectionKind::getReadOnly());
798 }
799
InitMCObjectFileInfo(const Triple & TheTriple,bool PIC,MCContext & ctx,bool LargeCodeModel)800 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
801 MCContext &ctx,
802 bool LargeCodeModel) {
803 PositionIndependent = PIC;
804 Ctx = &ctx;
805
806 // Common.
807 CommDirectiveSupportsAlignment = true;
808 SupportsWeakOmittedEHFrame = true;
809 SupportsCompactUnwindWithoutEHFrame = false;
810 OmitDwarfIfHaveCompactUnwind = false;
811
812 FDECFIEncoding = dwarf::DW_EH_PE_absptr;
813
814 CompactUnwindDwarfEHFrameOnly = 0;
815
816 EHFrameSection = nullptr; // Created on demand.
817 CompactUnwindSection = nullptr; // Used only by selected targets.
818 DwarfAccelNamesSection = nullptr; // Used only by selected targets.
819 DwarfAccelObjCSection = nullptr; // Used only by selected targets.
820 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
821 DwarfAccelTypesSection = nullptr; // Used only by selected targets.
822
823 TT = TheTriple;
824
825 switch (TT.getObjectFormat()) {
826 case Triple::MachO:
827 Env = IsMachO;
828 initMachOMCObjectFileInfo(TT);
829 break;
830 case Triple::COFF:
831 if (!TT.isOSWindows())
832 report_fatal_error(
833 "Cannot initialize MC for non-Windows COFF object files.");
834
835 Env = IsCOFF;
836 initCOFFMCObjectFileInfo(TT);
837 break;
838 case Triple::ELF:
839 Env = IsELF;
840 initELFMCObjectFileInfo(TT, LargeCodeModel);
841 break;
842 case Triple::Wasm:
843 Env = IsWasm;
844 initWasmMCObjectFileInfo(TT);
845 break;
846 case Triple::XCOFF:
847 Env = IsXCOFF;
848 initXCOFFMCObjectFileInfo(TT);
849 break;
850 case Triple::UnknownObjectFormat:
851 report_fatal_error("Cannot initialize MC for unknown object file format.");
852 break;
853 }
854 }
855
getDwarfComdatSection(const char * Name,uint64_t Hash) const856 MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name,
857 uint64_t Hash) const {
858 switch (TT.getObjectFormat()) {
859 case Triple::ELF:
860 return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0,
861 utostr(Hash));
862 case Triple::MachO:
863 case Triple::COFF:
864 case Triple::Wasm:
865 case Triple::XCOFF:
866 case Triple::UnknownObjectFormat:
867 report_fatal_error("Cannot get DWARF comdat section for this object file "
868 "format: not implemented.");
869 break;
870 }
871 llvm_unreachable("Unknown ObjectFormatType");
872 }
873
874 MCSection *
getStackSizesSection(const MCSection & TextSec) const875 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const {
876 if (Env != IsELF)
877 return StackSizesSection;
878
879 const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec);
880 unsigned Flags = ELF::SHF_LINK_ORDER;
881 StringRef GroupName;
882 if (const MCSymbol *Group = ElfSec.getGroup()) {
883 GroupName = Group->getName();
884 Flags |= ELF::SHF_GROUP;
885 }
886
887 const MCSymbol *Link = TextSec.getBeginSymbol();
888 auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()});
889 unsigned UniqueID = It.first->second;
890
891 return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0,
892 GroupName, UniqueID, cast<MCSymbolELF>(Link));
893 }
894