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/MC/MCAsmInfo.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCSection.h"
16 #include "llvm/MC/MCSectionCOFF.h"
17 #include "llvm/MC/MCSectionELF.h"
18 #include "llvm/MC/MCSectionMachO.h"
19 #include "llvm/Support/COFF.h"
20
21 using namespace llvm;
22
useCompactUnwind(const Triple & T)23 static bool useCompactUnwind(const Triple &T) {
24 // Only on darwin.
25 if (!T.isOSDarwin())
26 return false;
27
28 // aarch64 always has it.
29 if (T.getArch() == Triple::aarch64)
30 return true;
31
32 // armv7k always has it.
33 if (T.isWatchABI())
34 return true;
35
36 // Use it on newer version of OS X.
37 if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
38 return true;
39
40 // And the iOS simulator.
41 if (T.isiOS() &&
42 (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
43 return true;
44
45 return false;
46 }
47
initMachOMCObjectFileInfo(const Triple & T)48 void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) {
49 // MachO
50 SupportsWeakOmittedEHFrame = false;
51
52 EHFrameSection = Ctx->getMachOSection(
53 "__TEXT", "__eh_frame",
54 MachO::S_COALESCED | MachO::S_ATTR_NO_TOC |
55 MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT,
56 SectionKind::getReadOnly());
57
58 if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
59 SupportsCompactUnwindWithoutEHFrame = true;
60
61 if (T.isWatchABI())
62 OmitDwarfIfHaveCompactUnwind = true;
63
64 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
65 | dwarf::DW_EH_PE_sdata4;
66 LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
67 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
68 dwarf::DW_EH_PE_sdata4;
69
70 // .comm doesn't support alignment before Leopard.
71 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
72 CommDirectiveSupportsAlignment = false;
73
74 TextSection // .text
75 = Ctx->getMachOSection("__TEXT", "__text",
76 MachO::S_ATTR_PURE_INSTRUCTIONS,
77 SectionKind::getText());
78 DataSection // .data
79 = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData());
80
81 // BSSSection might not be expected initialized on msvc.
82 BSSSection = nullptr;
83
84 TLSDataSection // .tdata
85 = Ctx->getMachOSection("__DATA", "__thread_data",
86 MachO::S_THREAD_LOCAL_REGULAR,
87 SectionKind::getData());
88 TLSBSSSection // .tbss
89 = Ctx->getMachOSection("__DATA", "__thread_bss",
90 MachO::S_THREAD_LOCAL_ZEROFILL,
91 SectionKind::getThreadBSS());
92
93 // TODO: Verify datarel below.
94 TLSTLVSection // .tlv
95 = Ctx->getMachOSection("__DATA", "__thread_vars",
96 MachO::S_THREAD_LOCAL_VARIABLES,
97 SectionKind::getData());
98
99 TLSThreadInitSection = Ctx->getMachOSection(
100 "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
101 SectionKind::getData());
102
103 CStringSection // .cstring
104 = Ctx->getMachOSection("__TEXT", "__cstring",
105 MachO::S_CSTRING_LITERALS,
106 SectionKind::getMergeable1ByteCString());
107 UStringSection
108 = Ctx->getMachOSection("__TEXT","__ustring", 0,
109 SectionKind::getMergeable2ByteCString());
110 FourByteConstantSection // .literal4
111 = Ctx->getMachOSection("__TEXT", "__literal4",
112 MachO::S_4BYTE_LITERALS,
113 SectionKind::getMergeableConst4());
114 EightByteConstantSection // .literal8
115 = Ctx->getMachOSection("__TEXT", "__literal8",
116 MachO::S_8BYTE_LITERALS,
117 SectionKind::getMergeableConst8());
118
119 SixteenByteConstantSection // .literal16
120 = Ctx->getMachOSection("__TEXT", "__literal16",
121 MachO::S_16BYTE_LITERALS,
122 SectionKind::getMergeableConst16());
123
124 ReadOnlySection // .const
125 = Ctx->getMachOSection("__TEXT", "__const", 0,
126 SectionKind::getReadOnly());
127
128 // If the target is not powerpc, map the coal sections to the non-coal
129 // sections.
130 //
131 // "__TEXT/__textcoal_nt" => section "__TEXT/__text"
132 // "__TEXT/__const_coal" => section "__TEXT/__const"
133 // "__DATA/__datacoal_nt" => section "__DATA/__data"
134 Triple::ArchType ArchTy = T.getArch();
135
136 if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
137 TextCoalSection
138 = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
139 MachO::S_COALESCED |
140 MachO::S_ATTR_PURE_INSTRUCTIONS,
141 SectionKind::getText());
142 ConstTextCoalSection
143 = Ctx->getMachOSection("__TEXT", "__const_coal",
144 MachO::S_COALESCED,
145 SectionKind::getReadOnly());
146 DataCoalSection = Ctx->getMachOSection(
147 "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData());
148 } else {
149 TextCoalSection = TextSection;
150 ConstTextCoalSection = ReadOnlySection;
151 DataCoalSection = DataSection;
152 }
153
154 ConstDataSection // .const_data
155 = Ctx->getMachOSection("__DATA", "__const", 0,
156 SectionKind::getReadOnlyWithRel());
157 DataCommonSection
158 = Ctx->getMachOSection("__DATA","__common",
159 MachO::S_ZEROFILL,
160 SectionKind::getBSS());
161 DataBSSSection
162 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
163 SectionKind::getBSS());
164
165
166 LazySymbolPointerSection
167 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
168 MachO::S_LAZY_SYMBOL_POINTERS,
169 SectionKind::getMetadata());
170 NonLazySymbolPointerSection
171 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
172 MachO::S_NON_LAZY_SYMBOL_POINTERS,
173 SectionKind::getMetadata());
174
175 ThreadLocalPointerSection
176 = Ctx->getMachOSection("__DATA", "__thread_ptr",
177 MachO::S_THREAD_LOCAL_VARIABLE_POINTERS,
178 SectionKind::getMetadata());
179
180 if (!PositionIndependent) {
181 StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0,
182 SectionKind::getData());
183 StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0,
184 SectionKind::getData());
185 } else {
186 StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func",
187 MachO::S_MOD_INIT_FUNC_POINTERS,
188 SectionKind::getData());
189 StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func",
190 MachO::S_MOD_TERM_FUNC_POINTERS,
191 SectionKind::getData());
192 }
193
194 // Exception Handling.
195 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
196 SectionKind::getReadOnlyWithRel());
197
198 COFFDebugSymbolsSection = nullptr;
199 COFFDebugTypesSection = nullptr;
200
201 if (useCompactUnwind(T)) {
202 CompactUnwindSection =
203 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
204 SectionKind::getReadOnly());
205
206 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
207 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF
208 else if (T.getArch() == Triple::aarch64)
209 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF
210 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
211 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF
212 }
213
214 // Debug Information.
215 DwarfAccelNamesSection =
216 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
217 SectionKind::getMetadata(), "names_begin");
218 DwarfAccelObjCSection =
219 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
220 SectionKind::getMetadata(), "objc_begin");
221 // 16 character section limit...
222 DwarfAccelNamespaceSection =
223 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
224 SectionKind::getMetadata(), "namespac_begin");
225 DwarfAccelTypesSection =
226 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
227 SectionKind::getMetadata(), "types_begin");
228
229 DwarfAbbrevSection =
230 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
231 SectionKind::getMetadata(), "section_abbrev");
232 DwarfInfoSection =
233 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
234 SectionKind::getMetadata(), "section_info");
235 DwarfLineSection =
236 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
237 SectionKind::getMetadata(), "section_line");
238 DwarfFrameSection =
239 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
240 SectionKind::getMetadata());
241 DwarfPubNamesSection =
242 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
243 SectionKind::getMetadata());
244 DwarfPubTypesSection =
245 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
246 SectionKind::getMetadata());
247 DwarfGnuPubNamesSection =
248 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
249 SectionKind::getMetadata());
250 DwarfGnuPubTypesSection =
251 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
252 SectionKind::getMetadata());
253 DwarfStrSection =
254 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
255 SectionKind::getMetadata(), "info_string");
256 DwarfLocSection =
257 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
258 SectionKind::getMetadata(), "section_debug_loc");
259 DwarfARangesSection =
260 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
261 SectionKind::getMetadata());
262 DwarfRangesSection =
263 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
264 SectionKind::getMetadata(), "debug_range");
265 DwarfMacinfoSection =
266 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG,
267 SectionKind::getMetadata(), "debug_macinfo");
268 DwarfDebugInlineSection =
269 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
270 SectionKind::getMetadata());
271 DwarfCUIndexSection =
272 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
273 SectionKind::getMetadata());
274 DwarfTUIndexSection =
275 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG,
276 SectionKind::getMetadata());
277 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
278 0, SectionKind::getMetadata());
279
280 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
281 0, SectionKind::getMetadata());
282
283 TLSExtraDataSection = TLSTLVSection;
284 }
285
initELFMCObjectFileInfo(const Triple & T)286 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T) {
287 switch (T.getArch()) {
288 case Triple::mips:
289 case Triple::mipsel:
290 FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
291 break;
292 case Triple::mips64:
293 case Triple::mips64el:
294 FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
295 break;
296 case Triple::x86_64:
297 FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
298 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
299 : dwarf::DW_EH_PE_sdata4);
300 break;
301 default:
302 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
303 break;
304 }
305
306 switch (T.getArch()) {
307 case Triple::arm:
308 case Triple::armeb:
309 case Triple::thumb:
310 case Triple::thumbeb:
311 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
312 break;
313 // Fallthrough if not using EHABI
314 case Triple::ppc:
315 case Triple::x86:
316 PersonalityEncoding = PositionIndependent
317 ? dwarf::DW_EH_PE_indirect |
318 dwarf::DW_EH_PE_pcrel |
319 dwarf::DW_EH_PE_sdata4
320 : dwarf::DW_EH_PE_absptr;
321 LSDAEncoding = PositionIndependent
322 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
323 : dwarf::DW_EH_PE_absptr;
324 TTypeEncoding = PositionIndependent
325 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
326 dwarf::DW_EH_PE_sdata4
327 : dwarf::DW_EH_PE_absptr;
328 break;
329 case Triple::x86_64:
330 if (PositionIndependent) {
331 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
332 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
333 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
334 LSDAEncoding = dwarf::DW_EH_PE_pcrel |
335 (CMModel == CodeModel::Small
336 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
337 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
338 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
339 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
340 } else {
341 PersonalityEncoding =
342 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
343 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
344 LSDAEncoding = (CMModel == CodeModel::Small)
345 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
346 TTypeEncoding = (CMModel == CodeModel::Small)
347 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
348 }
349 break;
350 case Triple::hexagon:
351 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
352 LSDAEncoding = dwarf::DW_EH_PE_absptr;
353 FDECFIEncoding = dwarf::DW_EH_PE_absptr;
354 TTypeEncoding = dwarf::DW_EH_PE_absptr;
355 if (PositionIndependent) {
356 PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
357 LSDAEncoding |= dwarf::DW_EH_PE_pcrel;
358 FDECFIEncoding |= dwarf::DW_EH_PE_pcrel;
359 TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
360 }
361 break;
362 case Triple::aarch64:
363 case Triple::aarch64_be:
364 // The small model guarantees static code/data size < 4GB, but not where it
365 // will be in memory. Most of these could end up >2GB away so even a signed
366 // pc-relative 32-bit address is insufficient, theoretically.
367 if (PositionIndependent) {
368 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
369 dwarf::DW_EH_PE_sdata8;
370 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
371 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
372 dwarf::DW_EH_PE_sdata8;
373 } else {
374 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
375 LSDAEncoding = dwarf::DW_EH_PE_absptr;
376 TTypeEncoding = dwarf::DW_EH_PE_absptr;
377 }
378 break;
379 case Triple::lanai:
380 LSDAEncoding = dwarf::DW_EH_PE_absptr;
381 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
382 TTypeEncoding = dwarf::DW_EH_PE_absptr;
383 break;
384 case Triple::mips:
385 case Triple::mipsel:
386 case Triple::mips64:
387 case Triple::mips64el:
388 // MIPS uses indirect pointer to refer personality functions and types, so
389 // that the eh_frame section can be read-only. DW.ref.personality will be
390 // generated for relocation.
391 PersonalityEncoding = dwarf::DW_EH_PE_indirect;
392 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
393 // identify N64 from just a triple.
394 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
395 dwarf::DW_EH_PE_sdata4;
396 // We don't support PC-relative LSDA references in GAS so we use the default
397 // DW_EH_PE_absptr for those.
398 break;
399 case Triple::ppc64:
400 case Triple::ppc64le:
401 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
402 dwarf::DW_EH_PE_udata8;
403 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
404 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
405 dwarf::DW_EH_PE_udata8;
406 break;
407 case Triple::sparcel:
408 case Triple::sparc:
409 if (PositionIndependent) {
410 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
411 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
412 dwarf::DW_EH_PE_sdata4;
413 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
414 dwarf::DW_EH_PE_sdata4;
415 } else {
416 LSDAEncoding = dwarf::DW_EH_PE_absptr;
417 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
418 TTypeEncoding = dwarf::DW_EH_PE_absptr;
419 }
420 break;
421 case Triple::sparcv9:
422 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
423 if (PositionIndependent) {
424 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
425 dwarf::DW_EH_PE_sdata4;
426 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
427 dwarf::DW_EH_PE_sdata4;
428 } else {
429 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
430 TTypeEncoding = dwarf::DW_EH_PE_absptr;
431 }
432 break;
433 case Triple::systemz:
434 // All currently-defined code models guarantee that 4-byte PC-relative
435 // values will be in range.
436 if (PositionIndependent) {
437 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
438 dwarf::DW_EH_PE_sdata4;
439 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
440 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
441 dwarf::DW_EH_PE_sdata4;
442 } else {
443 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
444 LSDAEncoding = dwarf::DW_EH_PE_absptr;
445 TTypeEncoding = dwarf::DW_EH_PE_absptr;
446 }
447 break;
448 default:
449 break;
450 }
451
452 unsigned EHSectionType = T.getArch() == Triple::x86_64
453 ? ELF::SHT_X86_64_UNWIND
454 : ELF::SHT_PROGBITS;
455
456 // Solaris requires different flags for .eh_frame to seemingly every other
457 // platform.
458 unsigned EHSectionFlags = ELF::SHF_ALLOC;
459 if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
460 EHSectionFlags |= ELF::SHF_WRITE;
461
462 // ELF
463 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
464 ELF::SHF_WRITE | ELF::SHF_ALLOC);
465
466 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
467 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
468
469 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
470 ELF::SHF_WRITE | ELF::SHF_ALLOC);
471
472 ReadOnlySection =
473 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
474
475 TLSDataSection =
476 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
477 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
478
479 TLSBSSSection = Ctx->getELFSection(
480 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
481
482 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
483 ELF::SHF_ALLOC | ELF::SHF_WRITE);
484
485 MergeableConst4Section =
486 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
487 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
488
489 MergeableConst8Section =
490 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
491 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
492
493 MergeableConst16Section =
494 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
495 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
496
497 MergeableConst32Section =
498 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
499 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
500
501 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
502 ELF::SHF_ALLOC | ELF::SHF_WRITE);
503
504 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
505 ELF::SHF_ALLOC | ELF::SHF_WRITE);
506
507 // Exception Handling Sections.
508
509 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
510 // it contains relocatable pointers. In PIC mode, this is probably a big
511 // runtime hit for C++ apps. Either the contents of the LSDA need to be
512 // adjusted or this should be a data section.
513 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
514 ELF::SHF_ALLOC);
515
516 COFFDebugSymbolsSection = nullptr;
517 COFFDebugTypesSection = nullptr;
518
519 // Debug Info Sections.
520 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
521 "section_abbrev");
522 DwarfInfoSection =
523 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
524 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
525 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
526 DwarfPubNamesSection =
527 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
528 DwarfPubTypesSection =
529 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
530 DwarfGnuPubNamesSection =
531 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
532 DwarfGnuPubTypesSection =
533 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
534 DwarfStrSection =
535 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
536 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
537 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
538 DwarfARangesSection =
539 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
540 DwarfRangesSection =
541 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
542 DwarfMacinfoSection = Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS,
543 0, "debug_macinfo");
544
545 // DWARF5 Experimental Debug Info
546
547 // Accelerator Tables
548 DwarfAccelNamesSection =
549 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
550 DwarfAccelObjCSection =
551 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
552 DwarfAccelNamespaceSection = Ctx->getELFSection(
553 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
554 DwarfAccelTypesSection =
555 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
556
557 // Fission Sections
558 DwarfInfoDWOSection =
559 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
560 DwarfTypesDWOSection =
561 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
562 DwarfAbbrevDWOSection =
563 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
564 DwarfStrDWOSection =
565 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
566 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
567 DwarfLineDWOSection =
568 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
569 DwarfLocDWOSection =
570 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
571 DwarfStrOffDWOSection =
572 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
573 DwarfAddrSection =
574 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
575
576 // DWP Sections
577 DwarfCUIndexSection =
578 Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0);
579 DwarfTUIndexSection =
580 Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0);
581
582 StackMapSection =
583 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
584
585 FaultMapSection =
586 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
587
588 EHFrameSection =
589 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
590 }
591
initCOFFMCObjectFileInfo(const Triple & T)592 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
593 EHFrameSection = Ctx->getCOFFSection(
594 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
595 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
596 SectionKind::getData());
597
598 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is
599 // used to indicate to the linker that the text segment contains thumb instructions
600 // and to set the ISA selection bit for calls accordingly.
601 const bool IsThumb = T.getArch() == Triple::thumb;
602
603 CommDirectiveSupportsAlignment = true;
604
605 // COFF
606 BSSSection = Ctx->getCOFFSection(
607 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
608 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
609 SectionKind::getBSS());
610 TextSection = Ctx->getCOFFSection(
611 ".text",
612 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
613 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
614 COFF::IMAGE_SCN_MEM_READ,
615 SectionKind::getText());
616 DataSection = Ctx->getCOFFSection(
617 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
618 COFF::IMAGE_SCN_MEM_WRITE,
619 SectionKind::getData());
620 ReadOnlySection = Ctx->getCOFFSection(
621 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
622 SectionKind::getReadOnly());
623
624 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
625 StaticCtorSection =
626 Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
627 COFF::IMAGE_SCN_MEM_READ,
628 SectionKind::getReadOnly());
629 StaticDtorSection =
630 Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
631 COFF::IMAGE_SCN_MEM_READ,
632 SectionKind::getReadOnly());
633 } else {
634 StaticCtorSection = Ctx->getCOFFSection(
635 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
636 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
637 SectionKind::getData());
638 StaticDtorSection = Ctx->getCOFFSection(
639 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
640 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
641 SectionKind::getData());
642 }
643
644 // FIXME: We're emitting LSDA info into a readonly section on COFF, even
645 // though it contains relocatable pointers. In PIC mode, this is probably a
646 // big runtime hit for C++ apps. Either the contents of the LSDA need to be
647 // adjusted or this should be a data section.
648 if (T.getArch() == Triple::x86_64) {
649 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
650 LSDASection = nullptr;
651 } else {
652 LSDASection = Ctx->getCOFFSection(".gcc_except_table",
653 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
654 COFF::IMAGE_SCN_MEM_READ,
655 SectionKind::getReadOnly());
656 }
657
658 // Debug info.
659 COFFDebugSymbolsSection =
660 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
661 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
662 COFF::IMAGE_SCN_MEM_READ),
663 SectionKind::getMetadata());
664 COFFDebugTypesSection =
665 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
666 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
667 COFF::IMAGE_SCN_MEM_READ),
668 SectionKind::getMetadata());
669
670 DwarfAbbrevSection = Ctx->getCOFFSection(
671 ".debug_abbrev",
672 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
673 COFF::IMAGE_SCN_MEM_READ,
674 SectionKind::getMetadata(), "section_abbrev");
675 DwarfInfoSection = Ctx->getCOFFSection(
676 ".debug_info",
677 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
678 COFF::IMAGE_SCN_MEM_READ,
679 SectionKind::getMetadata(), "section_info");
680 DwarfLineSection = Ctx->getCOFFSection(
681 ".debug_line",
682 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
683 COFF::IMAGE_SCN_MEM_READ,
684 SectionKind::getMetadata(), "section_line");
685
686 DwarfFrameSection = Ctx->getCOFFSection(
687 ".debug_frame",
688 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
689 COFF::IMAGE_SCN_MEM_READ,
690 SectionKind::getMetadata());
691 DwarfPubNamesSection = Ctx->getCOFFSection(
692 ".debug_pubnames",
693 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
694 COFF::IMAGE_SCN_MEM_READ,
695 SectionKind::getMetadata());
696 DwarfPubTypesSection = Ctx->getCOFFSection(
697 ".debug_pubtypes",
698 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
699 COFF::IMAGE_SCN_MEM_READ,
700 SectionKind::getMetadata());
701 DwarfGnuPubNamesSection = Ctx->getCOFFSection(
702 ".debug_gnu_pubnames",
703 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
704 COFF::IMAGE_SCN_MEM_READ,
705 SectionKind::getMetadata());
706 DwarfGnuPubTypesSection = Ctx->getCOFFSection(
707 ".debug_gnu_pubtypes",
708 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
709 COFF::IMAGE_SCN_MEM_READ,
710 SectionKind::getMetadata());
711 DwarfStrSection = Ctx->getCOFFSection(
712 ".debug_str",
713 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
714 COFF::IMAGE_SCN_MEM_READ,
715 SectionKind::getMetadata(), "info_string");
716 DwarfLocSection = Ctx->getCOFFSection(
717 ".debug_loc",
718 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
719 COFF::IMAGE_SCN_MEM_READ,
720 SectionKind::getMetadata(), "section_debug_loc");
721 DwarfARangesSection = Ctx->getCOFFSection(
722 ".debug_aranges",
723 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
724 COFF::IMAGE_SCN_MEM_READ,
725 SectionKind::getMetadata());
726 DwarfRangesSection = Ctx->getCOFFSection(
727 ".debug_ranges",
728 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
729 COFF::IMAGE_SCN_MEM_READ,
730 SectionKind::getMetadata(), "debug_range");
731 DwarfMacinfoSection = Ctx->getCOFFSection(
732 ".debug_macinfo",
733 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
734 COFF::IMAGE_SCN_MEM_READ,
735 SectionKind::getMetadata(), "debug_macinfo");
736 DwarfInfoDWOSection = Ctx->getCOFFSection(
737 ".debug_info.dwo",
738 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
739 COFF::IMAGE_SCN_MEM_READ,
740 SectionKind::getMetadata(), "section_info_dwo");
741 DwarfTypesDWOSection = Ctx->getCOFFSection(
742 ".debug_types.dwo",
743 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
744 COFF::IMAGE_SCN_MEM_READ,
745 SectionKind::getMetadata(), "section_types_dwo");
746 DwarfAbbrevDWOSection = Ctx->getCOFFSection(
747 ".debug_abbrev.dwo",
748 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
749 COFF::IMAGE_SCN_MEM_READ,
750 SectionKind::getMetadata(), "section_abbrev_dwo");
751 DwarfStrDWOSection = Ctx->getCOFFSection(
752 ".debug_str.dwo",
753 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
754 COFF::IMAGE_SCN_MEM_READ,
755 SectionKind::getMetadata(), "skel_string");
756 DwarfLineDWOSection = Ctx->getCOFFSection(
757 ".debug_line.dwo",
758 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
759 COFF::IMAGE_SCN_MEM_READ,
760 SectionKind::getMetadata());
761 DwarfLocDWOSection = Ctx->getCOFFSection(
762 ".debug_loc.dwo",
763 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
764 COFF::IMAGE_SCN_MEM_READ,
765 SectionKind::getMetadata(), "skel_loc");
766 DwarfStrOffDWOSection = Ctx->getCOFFSection(
767 ".debug_str_offsets.dwo",
768 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
769 COFF::IMAGE_SCN_MEM_READ,
770 SectionKind::getMetadata());
771 DwarfAddrSection = Ctx->getCOFFSection(
772 ".debug_addr",
773 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
774 COFF::IMAGE_SCN_MEM_READ,
775 SectionKind::getMetadata(), "addr_sec");
776 DwarfCUIndexSection = Ctx->getCOFFSection(
777 ".debug_cu_index",
778 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
779 COFF::IMAGE_SCN_MEM_READ,
780 SectionKind::getMetadata());
781 DwarfTUIndexSection = Ctx->getCOFFSection(
782 ".debug_tu_index",
783 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
784 COFF::IMAGE_SCN_MEM_READ,
785 SectionKind::getMetadata());
786 DwarfAccelNamesSection = Ctx->getCOFFSection(
787 ".apple_names",
788 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
789 COFF::IMAGE_SCN_MEM_READ,
790 SectionKind::getMetadata(), "names_begin");
791 DwarfAccelNamespaceSection = Ctx->getCOFFSection(
792 ".apple_namespaces",
793 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
794 COFF::IMAGE_SCN_MEM_READ,
795 SectionKind::getMetadata(), "namespac_begin");
796 DwarfAccelTypesSection = Ctx->getCOFFSection(
797 ".apple_types",
798 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
799 COFF::IMAGE_SCN_MEM_READ,
800 SectionKind::getMetadata(), "types_begin");
801 DwarfAccelObjCSection = Ctx->getCOFFSection(
802 ".apple_objc",
803 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
804 COFF::IMAGE_SCN_MEM_READ,
805 SectionKind::getMetadata(), "objc_begin");
806
807 DrectveSection = Ctx->getCOFFSection(
808 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
809 SectionKind::getMetadata());
810
811 PDataSection = Ctx->getCOFFSection(
812 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
813 SectionKind::getData());
814
815 XDataSection = Ctx->getCOFFSection(
816 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
817 SectionKind::getData());
818
819 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
820 SectionKind::getMetadata());
821
822 TLSDataSection = Ctx->getCOFFSection(
823 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
824 COFF::IMAGE_SCN_MEM_WRITE,
825 SectionKind::getData());
826
827 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
828 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
829 COFF::IMAGE_SCN_MEM_READ,
830 SectionKind::getReadOnly());
831 }
832
InitMCObjectFileInfo(const Triple & TheTriple,bool PIC,CodeModel::Model cm,MCContext & ctx)833 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
834 CodeModel::Model cm,
835 MCContext &ctx) {
836 PositionIndependent = PIC;
837 CMModel = cm;
838 Ctx = &ctx;
839
840 // Common.
841 CommDirectiveSupportsAlignment = true;
842 SupportsWeakOmittedEHFrame = true;
843 SupportsCompactUnwindWithoutEHFrame = false;
844 OmitDwarfIfHaveCompactUnwind = false;
845
846 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
847 dwarf::DW_EH_PE_absptr;
848
849 CompactUnwindDwarfEHFrameOnly = 0;
850
851 EHFrameSection = nullptr; // Created on demand.
852 CompactUnwindSection = nullptr; // Used only by selected targets.
853 DwarfAccelNamesSection = nullptr; // Used only by selected targets.
854 DwarfAccelObjCSection = nullptr; // Used only by selected targets.
855 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
856 DwarfAccelTypesSection = nullptr; // Used only by selected targets.
857
858 TT = TheTriple;
859
860 switch (TT.getObjectFormat()) {
861 case Triple::MachO:
862 Env = IsMachO;
863 initMachOMCObjectFileInfo(TT);
864 break;
865 case Triple::COFF:
866 if (!TT.isOSWindows())
867 report_fatal_error(
868 "Cannot initialize MC for non-Windows COFF object files.");
869
870 Env = IsCOFF;
871 initCOFFMCObjectFileInfo(TT);
872 break;
873 case Triple::ELF:
874 Env = IsELF;
875 initELFMCObjectFileInfo(TT);
876 break;
877 case Triple::UnknownObjectFormat:
878 report_fatal_error("Cannot initialize MC for unknown object file format.");
879 break;
880 }
881 }
882
getDwarfTypesSection(uint64_t Hash) const883 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
884 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
885 0, utostr(Hash));
886 }
887