1 //===-- MObjectFileInfo.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 using namespace llvm;
20
useCompactUnwind(const Triple & T)21 static bool useCompactUnwind(const Triple &T) {
22 // Only on darwin.
23 if (!T.isOSDarwin())
24 return false;
25
26 // aarch64 always has it.
27 if (T.getArch() == Triple::aarch64)
28 return true;
29
30 // Use it on newer version of OS X.
31 if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
32 return true;
33
34 // And the iOS simulator.
35 if (T.isiOS() &&
36 (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
37 return true;
38
39 return false;
40 }
41
InitMachOMCObjectFileInfo(Triple T)42 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
43 // MachO
44 SupportsWeakOmittedEHFrame = false;
45
46 if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
47 SupportsCompactUnwindWithoutEHFrame = true;
48
49 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
50 | dwarf::DW_EH_PE_sdata4;
51 LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
52 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
53 dwarf::DW_EH_PE_sdata4;
54
55 // .comm doesn't support alignment before Leopard.
56 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
57 CommDirectiveSupportsAlignment = false;
58
59 TextSection // .text
60 = Ctx->getMachOSection("__TEXT", "__text",
61 MachO::S_ATTR_PURE_INSTRUCTIONS,
62 SectionKind::getText());
63 DataSection // .data
64 = Ctx->getMachOSection("__DATA", "__data", 0,
65 SectionKind::getDataRel());
66
67 // BSSSection might not be expected initialized on msvc.
68 BSSSection = nullptr;
69
70 TLSDataSection // .tdata
71 = Ctx->getMachOSection("__DATA", "__thread_data",
72 MachO::S_THREAD_LOCAL_REGULAR,
73 SectionKind::getDataRel());
74 TLSBSSSection // .tbss
75 = Ctx->getMachOSection("__DATA", "__thread_bss",
76 MachO::S_THREAD_LOCAL_ZEROFILL,
77 SectionKind::getThreadBSS());
78
79 // TODO: Verify datarel below.
80 TLSTLVSection // .tlv
81 = Ctx->getMachOSection("__DATA", "__thread_vars",
82 MachO::S_THREAD_LOCAL_VARIABLES,
83 SectionKind::getDataRel());
84
85 TLSThreadInitSection
86 = Ctx->getMachOSection("__DATA", "__thread_init",
87 MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
88 SectionKind::getDataRel());
89
90 CStringSection // .cstring
91 = Ctx->getMachOSection("__TEXT", "__cstring",
92 MachO::S_CSTRING_LITERALS,
93 SectionKind::getMergeable1ByteCString());
94 UStringSection
95 = Ctx->getMachOSection("__TEXT","__ustring", 0,
96 SectionKind::getMergeable2ByteCString());
97 FourByteConstantSection // .literal4
98 = Ctx->getMachOSection("__TEXT", "__literal4",
99 MachO::S_4BYTE_LITERALS,
100 SectionKind::getMergeableConst4());
101 EightByteConstantSection // .literal8
102 = Ctx->getMachOSection("__TEXT", "__literal8",
103 MachO::S_8BYTE_LITERALS,
104 SectionKind::getMergeableConst8());
105
106 SixteenByteConstantSection // .literal16
107 = Ctx->getMachOSection("__TEXT", "__literal16",
108 MachO::S_16BYTE_LITERALS,
109 SectionKind::getMergeableConst16());
110
111 ReadOnlySection // .const
112 = Ctx->getMachOSection("__TEXT", "__const", 0,
113 SectionKind::getReadOnly());
114
115 TextCoalSection
116 = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
117 MachO::S_COALESCED |
118 MachO::S_ATTR_PURE_INSTRUCTIONS,
119 SectionKind::getText());
120 ConstTextCoalSection
121 = Ctx->getMachOSection("__TEXT", "__const_coal",
122 MachO::S_COALESCED,
123 SectionKind::getReadOnly());
124 ConstDataSection // .const_data
125 = Ctx->getMachOSection("__DATA", "__const", 0,
126 SectionKind::getReadOnlyWithRel());
127 DataCoalSection
128 = Ctx->getMachOSection("__DATA","__datacoal_nt",
129 MachO::S_COALESCED,
130 SectionKind::getDataRel());
131 DataCommonSection
132 = Ctx->getMachOSection("__DATA","__common",
133 MachO::S_ZEROFILL,
134 SectionKind::getBSS());
135 DataBSSSection
136 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
137 SectionKind::getBSS());
138
139
140 LazySymbolPointerSection
141 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
142 MachO::S_LAZY_SYMBOL_POINTERS,
143 SectionKind::getMetadata());
144 NonLazySymbolPointerSection
145 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
146 MachO::S_NON_LAZY_SYMBOL_POINTERS,
147 SectionKind::getMetadata());
148
149 if (RelocM == Reloc::Static) {
150 StaticCtorSection
151 = Ctx->getMachOSection("__TEXT", "__constructor", 0,
152 SectionKind::getDataRel());
153 StaticDtorSection
154 = Ctx->getMachOSection("__TEXT", "__destructor", 0,
155 SectionKind::getDataRel());
156 } else {
157 StaticCtorSection
158 = Ctx->getMachOSection("__DATA", "__mod_init_func",
159 MachO::S_MOD_INIT_FUNC_POINTERS,
160 SectionKind::getDataRel());
161 StaticDtorSection
162 = Ctx->getMachOSection("__DATA", "__mod_term_func",
163 MachO::S_MOD_TERM_FUNC_POINTERS,
164 SectionKind::getDataRel());
165 }
166
167 // Exception Handling.
168 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
169 SectionKind::getReadOnlyWithRel());
170
171 COFFDebugSymbolsSection = nullptr;
172
173 if (useCompactUnwind(T)) {
174 CompactUnwindSection =
175 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
176 SectionKind::getReadOnly());
177
178 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
179 CompactUnwindDwarfEHFrameOnly = 0x04000000;
180 else if (T.getArch() == Triple::aarch64)
181 CompactUnwindDwarfEHFrameOnly = 0x03000000;
182 }
183
184 // Debug Information.
185 DwarfAccelNamesSection =
186 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
187 SectionKind::getMetadata(), "names_begin");
188 DwarfAccelObjCSection =
189 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
190 SectionKind::getMetadata(), "objc_begin");
191 // 16 character section limit...
192 DwarfAccelNamespaceSection =
193 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
194 SectionKind::getMetadata(), "namespac_begin");
195 DwarfAccelTypesSection =
196 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
197 SectionKind::getMetadata(), "types_begin");
198
199 DwarfAbbrevSection =
200 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
201 SectionKind::getMetadata(), "section_abbrev");
202 DwarfInfoSection =
203 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
204 SectionKind::getMetadata(), "section_info");
205 DwarfLineSection =
206 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
207 SectionKind::getMetadata(), "section_line");
208 DwarfFrameSection =
209 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
210 SectionKind::getMetadata());
211 DwarfPubNamesSection =
212 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
213 SectionKind::getMetadata());
214 DwarfPubTypesSection =
215 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
216 SectionKind::getMetadata());
217 DwarfGnuPubNamesSection =
218 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
219 SectionKind::getMetadata());
220 DwarfGnuPubTypesSection =
221 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
222 SectionKind::getMetadata());
223 DwarfStrSection =
224 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
225 SectionKind::getMetadata(), "info_string");
226 DwarfLocSection =
227 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
228 SectionKind::getMetadata(), "section_debug_loc");
229 DwarfARangesSection =
230 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
231 SectionKind::getMetadata());
232 DwarfRangesSection =
233 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
234 SectionKind::getMetadata(), "debug_range");
235 DwarfDebugInlineSection =
236 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
237 SectionKind::getMetadata());
238 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
239 0, SectionKind::getMetadata());
240
241 TLSExtraDataSection = TLSTLVSection;
242 }
243
InitELFMCObjectFileInfo(Triple T)244 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
245 switch (T.getArch()) {
246 case Triple::mips:
247 case Triple::mipsel:
248 FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
249 break;
250 case Triple::mips64:
251 case Triple::mips64el:
252 FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
253 break;
254 case Triple::x86_64:
255 FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
256 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
257 : dwarf::DW_EH_PE_sdata4);
258
259 break;
260 default:
261 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
262 break;
263 }
264
265 switch (T.getArch()) {
266 case Triple::arm:
267 case Triple::armeb:
268 case Triple::thumb:
269 case Triple::thumbeb:
270 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
271 break;
272 // Fallthrough if not using EHABI
273 case Triple::ppc:
274 case Triple::x86:
275 PersonalityEncoding = (RelocM == Reloc::PIC_)
276 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
277 : dwarf::DW_EH_PE_absptr;
278 LSDAEncoding = (RelocM == Reloc::PIC_)
279 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
280 : dwarf::DW_EH_PE_absptr;
281 TTypeEncoding = (RelocM == Reloc::PIC_)
282 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
283 : dwarf::DW_EH_PE_absptr;
284 break;
285 case Triple::x86_64:
286 if (RelocM == Reloc::PIC_) {
287 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
288 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
289 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
290 LSDAEncoding = dwarf::DW_EH_PE_pcrel |
291 (CMModel == CodeModel::Small
292 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
293 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
294 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
295 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
296 } else {
297 PersonalityEncoding =
298 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
299 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
300 LSDAEncoding = (CMModel == CodeModel::Small)
301 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
302 TTypeEncoding = (CMModel == CodeModel::Small)
303 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
304 }
305 break;
306 case Triple::aarch64:
307 case Triple::aarch64_be:
308 // The small model guarantees static code/data size < 4GB, but not where it
309 // will be in memory. Most of these could end up >2GB away so even a signed
310 // pc-relative 32-bit address is insufficient, theoretically.
311 if (RelocM == Reloc::PIC_) {
312 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
313 dwarf::DW_EH_PE_sdata8;
314 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
315 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
316 dwarf::DW_EH_PE_sdata8;
317 } else {
318 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
319 LSDAEncoding = dwarf::DW_EH_PE_absptr;
320 TTypeEncoding = dwarf::DW_EH_PE_absptr;
321 }
322 break;
323 case Triple::mips:
324 case Triple::mipsel:
325 case Triple::mips64:
326 case Triple::mips64el:
327 // MIPS uses indirect pointer to refer personality functions, so that the
328 // eh_frame section can be read-only. DW.ref.personality will be generated
329 // for relocation.
330 PersonalityEncoding = dwarf::DW_EH_PE_indirect;
331 break;
332 case Triple::ppc64:
333 case Triple::ppc64le:
334 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
335 dwarf::DW_EH_PE_udata8;
336 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
337 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
338 dwarf::DW_EH_PE_udata8;
339 break;
340 case Triple::sparc:
341 if (RelocM == Reloc::PIC_) {
342 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
343 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
344 dwarf::DW_EH_PE_sdata4;
345 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
346 dwarf::DW_EH_PE_sdata4;
347 } else {
348 LSDAEncoding = dwarf::DW_EH_PE_absptr;
349 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
350 TTypeEncoding = dwarf::DW_EH_PE_absptr;
351 }
352 break;
353 case Triple::sparcv9:
354 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
355 if (RelocM == Reloc::PIC_) {
356 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
357 dwarf::DW_EH_PE_sdata4;
358 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
359 dwarf::DW_EH_PE_sdata4;
360 } else {
361 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
362 TTypeEncoding = dwarf::DW_EH_PE_absptr;
363 }
364 break;
365 case Triple::systemz:
366 // All currently-defined code models guarantee that 4-byte PC-relative
367 // values will be in range.
368 if (RelocM == Reloc::PIC_) {
369 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
370 dwarf::DW_EH_PE_sdata4;
371 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
372 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
373 dwarf::DW_EH_PE_sdata4;
374 } else {
375 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
376 LSDAEncoding = dwarf::DW_EH_PE_absptr;
377 TTypeEncoding = dwarf::DW_EH_PE_absptr;
378 }
379 break;
380 default:
381 break;
382 }
383
384 // Solaris requires different flags for .eh_frame to seemingly every other
385 // platform.
386 EHSectionType = ELF::SHT_PROGBITS;
387 EHSectionFlags = ELF::SHF_ALLOC;
388 if (T.isOSSolaris()) {
389 if (T.getArch() == Triple::x86_64)
390 EHSectionType = ELF::SHT_X86_64_UNWIND;
391 else
392 EHSectionFlags |= ELF::SHF_WRITE;
393 }
394
395
396 // ELF
397 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
398 ELF::SHF_WRITE | ELF::SHF_ALLOC);
399
400 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
401 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
402
403 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
404 ELF::SHF_WRITE | ELF::SHF_ALLOC);
405
406 ReadOnlySection =
407 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
408
409 TLSDataSection =
410 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
411 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
412
413 TLSBSSSection = Ctx->getELFSection(
414 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
415
416 DataRelSection = Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
417 ELF::SHF_ALLOC | ELF::SHF_WRITE);
418
419 DataRelLocalSection = Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
420 ELF::SHF_ALLOC | ELF::SHF_WRITE);
421
422 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
423 ELF::SHF_ALLOC | ELF::SHF_WRITE);
424
425 DataRelROLocalSection = Ctx->getELFSection(
426 ".data.rel.ro.local", ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_WRITE);
427
428 MergeableConst4Section =
429 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
430 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
431
432 MergeableConst8Section =
433 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
434 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
435
436 MergeableConst16Section =
437 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
438 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
439
440 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
441 ELF::SHF_ALLOC | ELF::SHF_WRITE);
442
443 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
444 ELF::SHF_ALLOC | ELF::SHF_WRITE);
445
446 // Exception Handling Sections.
447
448 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
449 // it contains relocatable pointers. In PIC mode, this is probably a big
450 // runtime hit for C++ apps. Either the contents of the LSDA need to be
451 // adjusted or this should be a data section.
452 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
453 ELF::SHF_ALLOC);
454
455 COFFDebugSymbolsSection = nullptr;
456
457 // Debug Info Sections.
458 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
459 "section_abbrev");
460 DwarfInfoSection =
461 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
462 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
463 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
464 DwarfPubNamesSection =
465 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
466 DwarfPubTypesSection =
467 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
468 DwarfGnuPubNamesSection =
469 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
470 DwarfGnuPubTypesSection =
471 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
472 DwarfStrSection =
473 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
474 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
475 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
476 DwarfARangesSection =
477 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
478 DwarfRangesSection =
479 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
480
481 // DWARF5 Experimental Debug Info
482
483 // Accelerator Tables
484 DwarfAccelNamesSection =
485 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
486 DwarfAccelObjCSection =
487 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
488 DwarfAccelNamespaceSection = Ctx->getELFSection(
489 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
490 DwarfAccelTypesSection =
491 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
492
493 // Fission Sections
494 DwarfInfoDWOSection =
495 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
496 DwarfTypesDWOSection =
497 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
498 DwarfAbbrevDWOSection =
499 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
500 DwarfStrDWOSection =
501 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
502 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
503 DwarfLineDWOSection =
504 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
505 DwarfLocDWOSection =
506 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
507 DwarfStrOffDWOSection =
508 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
509 DwarfAddrSection =
510 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
511
512 StackMapSection =
513 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
514 }
515
InitCOFFMCObjectFileInfo(Triple T)516 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
517 bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
518
519 CommDirectiveSupportsAlignment = true;
520
521 // COFF
522 BSSSection = Ctx->getCOFFSection(
523 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
524 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
525 SectionKind::getBSS());
526 TextSection = Ctx->getCOFFSection(
527 ".text",
528 (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
529 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
530 COFF::IMAGE_SCN_MEM_READ,
531 SectionKind::getText());
532 DataSection = Ctx->getCOFFSection(
533 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
534 COFF::IMAGE_SCN_MEM_WRITE,
535 SectionKind::getDataRel());
536 ReadOnlySection = Ctx->getCOFFSection(
537 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
538 SectionKind::getReadOnly());
539
540 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
541 StaticCtorSection =
542 Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
543 COFF::IMAGE_SCN_MEM_READ,
544 SectionKind::getReadOnly());
545 StaticDtorSection =
546 Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
547 COFF::IMAGE_SCN_MEM_READ,
548 SectionKind::getReadOnly());
549 } else {
550 StaticCtorSection = Ctx->getCOFFSection(
551 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
552 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
553 SectionKind::getDataRel());
554 StaticDtorSection = Ctx->getCOFFSection(
555 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
556 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
557 SectionKind::getDataRel());
558 }
559
560 // FIXME: We're emitting LSDA info into a readonly section on COFF, even
561 // though it contains relocatable pointers. In PIC mode, this is probably a
562 // big runtime hit for C++ apps. Either the contents of the LSDA need to be
563 // adjusted or this should be a data section.
564 assert(T.isOSWindows() && "Windows is the only supported COFF target");
565 if (T.getArch() == Triple::x86_64) {
566 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
567 LSDASection = 0;
568 } else {
569 LSDASection = Ctx->getCOFFSection(".gcc_except_table",
570 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
571 COFF::IMAGE_SCN_MEM_READ,
572 SectionKind::getReadOnly());
573 }
574
575 // Debug info.
576 COFFDebugSymbolsSection =
577 Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
578 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
579 COFF::IMAGE_SCN_MEM_READ,
580 SectionKind::getMetadata());
581
582 DwarfAbbrevSection = Ctx->getCOFFSection(
583 ".debug_abbrev",
584 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
585 COFF::IMAGE_SCN_MEM_READ,
586 SectionKind::getMetadata(), "section_abbrev");
587 DwarfInfoSection = Ctx->getCOFFSection(
588 ".debug_info",
589 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
590 COFF::IMAGE_SCN_MEM_READ,
591 SectionKind::getMetadata(), "section_info");
592 DwarfLineSection = Ctx->getCOFFSection(
593 ".debug_line",
594 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
595 COFF::IMAGE_SCN_MEM_READ,
596 SectionKind::getMetadata(), "section_line");
597
598 DwarfFrameSection = Ctx->getCOFFSection(
599 ".debug_frame",
600 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
601 COFF::IMAGE_SCN_MEM_READ,
602 SectionKind::getMetadata());
603 DwarfPubNamesSection = Ctx->getCOFFSection(
604 ".debug_pubnames",
605 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
606 COFF::IMAGE_SCN_MEM_READ,
607 SectionKind::getMetadata());
608 DwarfPubTypesSection = Ctx->getCOFFSection(
609 ".debug_pubtypes",
610 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
611 COFF::IMAGE_SCN_MEM_READ,
612 SectionKind::getMetadata());
613 DwarfGnuPubNamesSection = Ctx->getCOFFSection(
614 ".debug_gnu_pubnames",
615 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
616 COFF::IMAGE_SCN_MEM_READ,
617 SectionKind::getMetadata());
618 DwarfGnuPubTypesSection = Ctx->getCOFFSection(
619 ".debug_gnu_pubtypes",
620 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
621 COFF::IMAGE_SCN_MEM_READ,
622 SectionKind::getMetadata());
623 DwarfStrSection = Ctx->getCOFFSection(
624 ".debug_str",
625 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
626 COFF::IMAGE_SCN_MEM_READ,
627 SectionKind::getMetadata(), "info_string");
628 DwarfLocSection = Ctx->getCOFFSection(
629 ".debug_loc",
630 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
631 COFF::IMAGE_SCN_MEM_READ,
632 SectionKind::getMetadata(), "section_debug_loc");
633 DwarfARangesSection = Ctx->getCOFFSection(
634 ".debug_aranges",
635 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
636 COFF::IMAGE_SCN_MEM_READ,
637 SectionKind::getMetadata());
638 DwarfRangesSection = Ctx->getCOFFSection(
639 ".debug_ranges",
640 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
641 COFF::IMAGE_SCN_MEM_READ,
642 SectionKind::getMetadata(), "debug_range");
643 DwarfInfoDWOSection = Ctx->getCOFFSection(
644 ".debug_info.dwo",
645 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
646 COFF::IMAGE_SCN_MEM_READ,
647 SectionKind::getMetadata(), "section_info_dwo");
648 DwarfTypesDWOSection = Ctx->getCOFFSection(
649 ".debug_types.dwo",
650 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
651 COFF::IMAGE_SCN_MEM_READ,
652 SectionKind::getMetadata(), "section_types_dwo");
653 DwarfAbbrevDWOSection = Ctx->getCOFFSection(
654 ".debug_abbrev.dwo",
655 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
656 COFF::IMAGE_SCN_MEM_READ,
657 SectionKind::getMetadata(), "section_abbrev_dwo");
658 DwarfStrDWOSection = Ctx->getCOFFSection(
659 ".debug_str.dwo",
660 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
661 COFF::IMAGE_SCN_MEM_READ,
662 SectionKind::getMetadata(), "skel_string");
663 DwarfLineDWOSection = Ctx->getCOFFSection(
664 ".debug_line.dwo",
665 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
666 COFF::IMAGE_SCN_MEM_READ,
667 SectionKind::getMetadata());
668 DwarfLocDWOSection = Ctx->getCOFFSection(
669 ".debug_loc.dwo",
670 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
671 COFF::IMAGE_SCN_MEM_READ,
672 SectionKind::getMetadata(), "skel_loc");
673 DwarfStrOffDWOSection = Ctx->getCOFFSection(
674 ".debug_str_offsets.dwo",
675 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
676 COFF::IMAGE_SCN_MEM_READ,
677 SectionKind::getMetadata());
678 DwarfAddrSection = Ctx->getCOFFSection(
679 ".debug_addr",
680 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
681 COFF::IMAGE_SCN_MEM_READ,
682 SectionKind::getMetadata(), "addr_sec");
683 DwarfAccelNamesSection = Ctx->getCOFFSection(
684 ".apple_names",
685 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
686 COFF::IMAGE_SCN_MEM_READ,
687 SectionKind::getMetadata(), "names_begin");
688 DwarfAccelNamespaceSection = Ctx->getCOFFSection(
689 ".apple_namespaces",
690 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
691 COFF::IMAGE_SCN_MEM_READ,
692 SectionKind::getMetadata(), "namespac_begin");
693 DwarfAccelTypesSection = Ctx->getCOFFSection(
694 ".apple_types",
695 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
696 COFF::IMAGE_SCN_MEM_READ,
697 SectionKind::getMetadata(), "types_begin");
698 DwarfAccelObjCSection = Ctx->getCOFFSection(
699 ".apple_objc",
700 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
701 COFF::IMAGE_SCN_MEM_READ,
702 SectionKind::getMetadata(), "objc_begin");
703
704 DrectveSection = Ctx->getCOFFSection(
705 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
706 SectionKind::getMetadata());
707
708 PDataSection = Ctx->getCOFFSection(
709 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
710 SectionKind::getDataRel());
711
712 XDataSection = Ctx->getCOFFSection(
713 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
714 SectionKind::getDataRel());
715
716 TLSDataSection = Ctx->getCOFFSection(
717 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
718 COFF::IMAGE_SCN_MEM_WRITE,
719 SectionKind::getDataRel());
720 }
721
InitMCObjectFileInfo(StringRef T,Reloc::Model relocm,CodeModel::Model cm,MCContext & ctx)722 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef T, Reloc::Model relocm,
723 CodeModel::Model cm,
724 MCContext &ctx) {
725 RelocM = relocm;
726 CMModel = cm;
727 Ctx = &ctx;
728
729 // Common.
730 CommDirectiveSupportsAlignment = true;
731 SupportsWeakOmittedEHFrame = true;
732 SupportsCompactUnwindWithoutEHFrame = false;
733
734 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
735 dwarf::DW_EH_PE_absptr;
736
737 CompactUnwindDwarfEHFrameOnly = 0;
738
739 EHFrameSection = nullptr; // Created on demand.
740 CompactUnwindSection = nullptr; // Used only by selected targets.
741 DwarfAccelNamesSection = nullptr; // Used only by selected targets.
742 DwarfAccelObjCSection = nullptr; // Used only by selected targets.
743 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
744 DwarfAccelTypesSection = nullptr; // Used only by selected targets.
745
746 TT = Triple(T);
747
748 Triple::ArchType Arch = TT.getArch();
749 // FIXME: Checking for Arch here to filter out bogus triples such as
750 // cellspu-apple-darwin. Perhaps we should fix in Triple?
751 if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
752 Arch == Triple::arm || Arch == Triple::thumb ||
753 Arch == Triple::aarch64 ||
754 Arch == Triple::ppc || Arch == Triple::ppc64 ||
755 Arch == Triple::UnknownArch) &&
756 (TT.isOSDarwin() || TT.isOSBinFormatMachO())) {
757 Env = IsMachO;
758 InitMachOMCObjectFileInfo(TT);
759 } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
760 Arch == Triple::arm || Arch == Triple::thumb) &&
761 (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
762 Env = IsCOFF;
763 InitCOFFMCObjectFileInfo(TT);
764 } else {
765 Env = IsELF;
766 InitELFMCObjectFileInfo(TT);
767 }
768 }
769
getDwarfTypesSection(uint64_t Hash) const770 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
771 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
772 0, utostr(Hash));
773 }
774
InitEHFrameSection()775 void MCObjectFileInfo::InitEHFrameSection() {
776 if (Env == IsMachO)
777 EHFrameSection =
778 Ctx->getMachOSection("__TEXT", "__eh_frame",
779 MachO::S_COALESCED |
780 MachO::S_ATTR_NO_TOC |
781 MachO::S_ATTR_STRIP_STATIC_SYMS |
782 MachO::S_ATTR_LIVE_SUPPORT,
783 SectionKind::getReadOnly());
784 else if (Env == IsELF)
785 EHFrameSection =
786 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
787 else
788 EHFrameSection =
789 Ctx->getCOFFSection(".eh_frame",
790 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
791 COFF::IMAGE_SCN_MEM_READ |
792 COFF::IMAGE_SCN_MEM_WRITE,
793 SectionKind::getDataRel());
794 }
795