1//===- ELFObjectFile.cpp - ELF object file implementation -----------------===//
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// Part of the ELFObjectFile class implementation.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/Object/ELFObjectFile.h"
14#include "llvm/BinaryFormat/ELF.h"
15#include "llvm/MC/MCInstrAnalysis.h"
16#include "llvm/MC/TargetRegistry.h"
17#include "llvm/Object/ELF.h"
18#include "llvm/Object/ELFTypes.h"
19#include "llvm/Object/Error.h"
20#include "llvm/Support/ARMAttributeParser.h"
21#include "llvm/Support/ARMBuildAttributes.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/HexagonAttributeParser.h"
24#include "llvm/Support/RISCVAttributeParser.h"
25#include "llvm/Support/RISCVAttributes.h"
26#include "llvm/TargetParser/RISCVISAInfo.h"
27#include "llvm/TargetParser/SubtargetFeature.h"
28#include "llvm/TargetParser/Triple.h"
29#include <algorithm>
30#include <cstddef>
31#include <cstdint>
32#include <memory>
33#include <optional>
34#include <string>
35#include <utility>
36
37using namespace llvm;
38using namespace object;
39
40EnumStrings<uint8_t, 2> llvm::object::getElfSymbolTypes() {
41 constexpr EnumStringDef<uint8_t, 2> ElfSymbolTypeDefs[] = {
42 {.Names: {"None", "NOTYPE"}, .Value: ELF::STT_NOTYPE},
43 {.Names: {"Object", "OBJECT"}, .Value: ELF::STT_OBJECT},
44 {.Names: {"Function", "FUNC"}, .Value: ELF::STT_FUNC},
45 {.Names: {"Section", "SECTION"}, .Value: ELF::STT_SECTION},
46 {.Names: {"File", "FILE"}, .Value: ELF::STT_FILE},
47 {.Names: {"Common", "COMMON"}, .Value: ELF::STT_COMMON},
48 {.Names: {"TLS", "TLS"}, .Value: ELF::STT_TLS},
49 {.Names: {"Unknown", "<unknown>: 7"}, .Value: 7},
50 {.Names: {"Unknown", "<unknown>: 8"}, .Value: 8},
51 {.Names: {"Unknown", "<unknown>: 9"}, .Value: 9},
52 {.Names: {"GNU_IFunc", "IFUNC"}, .Value: ELF::STT_GNU_IFUNC},
53 {.Names: {"OS Specific", "<OS specific>: 11"}, .Value: 11},
54 {.Names: {"OS Specific", "<OS specific>: 12"}, .Value: 12},
55 {.Names: {"Proc Specific", "<processor specific>: 13"}, .Value: 13},
56 {.Names: {"Proc Specific", "<processor specific>: 14"}, .Value: 14},
57 {.Names: {"Proc Specific", "<processor specific>: 15"}, .Value: 15},
58 };
59 static constexpr auto ElfSymbolTypes = BUILD_ENUM_STRINGS(ElfSymbolTypeDefs);
60 return ElfSymbolTypes;
61}
62
63ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source)
64 : ObjectFile(Type, Source) {}
65
66template <class ELFT>
67static Expected<std::unique_ptr<ELFObjectFile<ELFT>>>
68createPtr(MemoryBufferRef Object, bool InitContent) {
69 auto Ret = ELFObjectFile<ELFT>::create(Object, InitContent);
70 if (Error E = Ret.takeError())
71 return std::move(E);
72 return std::make_unique<ELFObjectFile<ELFT>>(std::move(*Ret));
73}
74
75Expected<std::unique_ptr<ObjectFile>>
76ObjectFile::createELFObjectFile(MemoryBufferRef Obj, bool InitContent) {
77 std::pair<unsigned char, unsigned char> Ident =
78 getElfArchType(Object: Obj.getBuffer());
79 std::size_t MaxAlignment =
80 1ULL << llvm::countr_zero(
81 Val: reinterpret_cast<uintptr_t>(Obj.getBufferStart()));
82
83 if (MaxAlignment < 2)
84 return createError(Err: "Insufficient alignment");
85
86 if (Ident.first == ELF::ELFCLASS32) {
87 if (Ident.second == ELF::ELFDATA2LSB)
88 return createPtr<ELF32LE>(Object: Obj, InitContent);
89 else if (Ident.second == ELF::ELFDATA2MSB)
90 return createPtr<ELF32BE>(Object: Obj, InitContent);
91 else
92 return createError(Err: "Invalid ELF data");
93 } else if (Ident.first == ELF::ELFCLASS64) {
94 if (Ident.second == ELF::ELFDATA2LSB)
95 return createPtr<ELF64LE>(Object: Obj, InitContent);
96 else if (Ident.second == ELF::ELFDATA2MSB)
97 return createPtr<ELF64BE>(Object: Obj, InitContent);
98 else
99 return createError(Err: "Invalid ELF data");
100 }
101 return createError(Err: "Invalid ELF class");
102}
103
104SubtargetFeatures ELFObjectFileBase::getMIPSFeatures() const {
105 SubtargetFeatures Features;
106 unsigned PlatformFlags = getPlatformFlags();
107
108 switch (PlatformFlags & ELF::EF_MIPS_ARCH) {
109 case ELF::EF_MIPS_ARCH_1:
110 break;
111 case ELF::EF_MIPS_ARCH_2:
112 Features.AddFeature(String: "mips2");
113 break;
114 case ELF::EF_MIPS_ARCH_3:
115 Features.AddFeature(String: "mips3");
116 break;
117 case ELF::EF_MIPS_ARCH_4:
118 Features.AddFeature(String: "mips4");
119 break;
120 case ELF::EF_MIPS_ARCH_5:
121 Features.AddFeature(String: "mips5");
122 break;
123 case ELF::EF_MIPS_ARCH_32:
124 Features.AddFeature(String: "mips32");
125 break;
126 case ELF::EF_MIPS_ARCH_64:
127 Features.AddFeature(String: "mips64");
128 break;
129 case ELF::EF_MIPS_ARCH_32R2:
130 Features.AddFeature(String: "mips32r2");
131 break;
132 case ELF::EF_MIPS_ARCH_64R2:
133 Features.AddFeature(String: "mips64r2");
134 break;
135 case ELF::EF_MIPS_ARCH_32R6:
136 Features.AddFeature(String: "mips32r6");
137 break;
138 case ELF::EF_MIPS_ARCH_64R6:
139 Features.AddFeature(String: "mips64r6");
140 break;
141 default:
142 llvm_unreachable("Unknown EF_MIPS_ARCH value");
143 }
144
145 switch (PlatformFlags & ELF::EF_MIPS_MACH) {
146 case ELF::EF_MIPS_MACH_NONE:
147 // No feature associated with this value.
148 break;
149 case ELF::EF_MIPS_MACH_OCTEON:
150 Features.AddFeature(String: "cnmips");
151 break;
152 default:
153 llvm_unreachable("Unknown EF_MIPS_ARCH value");
154 }
155
156 if (PlatformFlags & ELF::EF_MIPS_ARCH_ASE_M16)
157 Features.AddFeature(String: "mips16");
158 if (PlatformFlags & ELF::EF_MIPS_MICROMIPS)
159 Features.AddFeature(String: "micromips");
160
161 return Features;
162}
163
164SubtargetFeatures ELFObjectFileBase::getARMFeatures() const {
165 SubtargetFeatures Features;
166 ARMAttributeParser Attributes;
167 if (Error E = getBuildAttributes(Attributes)) {
168 consumeError(Err: std::move(E));
169 return SubtargetFeatures();
170 }
171
172 // both ARMv7-M and R have to support thumb hardware div
173 bool isV7 = false;
174 std::optional<unsigned> Attr =
175 Attributes.getAttributeValue(tag: ARMBuildAttrs::CPU_arch);
176 if (Attr)
177 isV7 = *Attr == ARMBuildAttrs::v7;
178
179 Attr = Attributes.getAttributeValue(tag: ARMBuildAttrs::CPU_arch_profile);
180 if (Attr) {
181 switch (*Attr) {
182 case ARMBuildAttrs::ApplicationProfile:
183 Features.AddFeature(String: "aclass");
184 break;
185 case ARMBuildAttrs::RealTimeProfile:
186 Features.AddFeature(String: "rclass");
187 if (isV7)
188 Features.AddFeature(String: "hwdiv");
189 break;
190 case ARMBuildAttrs::MicroControllerProfile:
191 Features.AddFeature(String: "mclass");
192 if (isV7)
193 Features.AddFeature(String: "hwdiv");
194 break;
195 }
196 }
197
198 Attr = Attributes.getAttributeValue(tag: ARMBuildAttrs::THUMB_ISA_use);
199 if (Attr) {
200 switch (*Attr) {
201 default:
202 break;
203 case ARMBuildAttrs::Not_Allowed:
204 Features.AddFeature(String: "thumb", Enable: false);
205 Features.AddFeature(String: "thumb2", Enable: false);
206 break;
207 case ARMBuildAttrs::AllowThumb32:
208 Features.AddFeature(String: "thumb2");
209 break;
210 }
211 }
212
213 Attr = Attributes.getAttributeValue(tag: ARMBuildAttrs::FP_arch);
214 if (Attr) {
215 switch (*Attr) {
216 default:
217 break;
218 case ARMBuildAttrs::Not_Allowed:
219 Features.AddFeature(String: "vfp2sp", Enable: false);
220 Features.AddFeature(String: "vfp3d16sp", Enable: false);
221 Features.AddFeature(String: "vfp4d16sp", Enable: false);
222 break;
223 case ARMBuildAttrs::AllowFPv2:
224 Features.AddFeature(String: "vfp2");
225 break;
226 case ARMBuildAttrs::AllowFPv3A:
227 case ARMBuildAttrs::AllowFPv3B:
228 Features.AddFeature(String: "vfp3");
229 break;
230 case ARMBuildAttrs::AllowFPv4A:
231 case ARMBuildAttrs::AllowFPv4B:
232 Features.AddFeature(String: "vfp4");
233 break;
234 }
235 }
236
237 Attr = Attributes.getAttributeValue(tag: ARMBuildAttrs::Advanced_SIMD_arch);
238 if (Attr) {
239 switch (*Attr) {
240 default:
241 break;
242 case ARMBuildAttrs::Not_Allowed:
243 Features.AddFeature(String: "neon", Enable: false);
244 Features.AddFeature(String: "fp16", Enable: false);
245 break;
246 case ARMBuildAttrs::AllowNeon:
247 Features.AddFeature(String: "neon");
248 break;
249 case ARMBuildAttrs::AllowNeon2:
250 Features.AddFeature(String: "neon");
251 Features.AddFeature(String: "fp16");
252 break;
253 }
254 }
255
256 Attr = Attributes.getAttributeValue(tag: ARMBuildAttrs::MVE_arch);
257 if (Attr) {
258 switch (*Attr) {
259 default:
260 break;
261 case ARMBuildAttrs::Not_Allowed:
262 Features.AddFeature(String: "mve", Enable: false);
263 Features.AddFeature(String: "mve.fp", Enable: false);
264 break;
265 case ARMBuildAttrs::AllowMVEInteger:
266 Features.AddFeature(String: "mve.fp", Enable: false);
267 Features.AddFeature(String: "mve");
268 break;
269 case ARMBuildAttrs::AllowMVEIntegerAndFloat:
270 Features.AddFeature(String: "mve.fp");
271 break;
272 }
273 }
274
275 Attr = Attributes.getAttributeValue(tag: ARMBuildAttrs::DIV_use);
276 if (Attr) {
277 switch (*Attr) {
278 default:
279 break;
280 case ARMBuildAttrs::DisallowDIV:
281 Features.AddFeature(String: "hwdiv", Enable: false);
282 Features.AddFeature(String: "hwdiv-arm", Enable: false);
283 break;
284 case ARMBuildAttrs::AllowDIVExt:
285 Features.AddFeature(String: "hwdiv");
286 Features.AddFeature(String: "hwdiv-arm");
287 break;
288 }
289 }
290
291 return Features;
292}
293
294static std::string hexagonAttrToFeatureString(unsigned Attr) {
295 return "v" + utostr(X: Attr);
296}
297
298SubtargetFeatures ELFObjectFileBase::getHexagonFeatures() const {
299 SubtargetFeatures Features;
300 HexagonAttributeParser Parser;
301 if (Error E = getBuildAttributes(Attributes&: Parser)) {
302 // Return no attributes if none can be read.
303 // This behavior is important for backwards compatibility.
304 consumeError(Err: std::move(E));
305 return Features;
306 }
307 std::optional<unsigned> Attr;
308
309 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::ARCH)))
310 Features.AddFeature(String: hexagonAttrToFeatureString(Attr: *Attr));
311
312 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::HVXARCH)))
313 Features.AddFeature(String: "hvx" + hexagonAttrToFeatureString(Attr: *Attr));
314
315 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::HVXIEEEFP)))
316 if (*Attr)
317 Features.AddFeature(String: "hvx-ieee-fp");
318
319 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::HVXQFLOAT)))
320 if (*Attr)
321 Features.AddFeature(String: "hvx-qfloat");
322
323 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::ZREG)))
324 if (*Attr)
325 Features.AddFeature(String: "zreg");
326
327 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::AUDIO)))
328 if (*Attr)
329 Features.AddFeature(String: "audio");
330
331 if ((Attr = Parser.getAttributeValue(tag: HexagonAttrs::CABAC)))
332 if (*Attr)
333 Features.AddFeature(String: "cabac");
334
335 return Features;
336}
337
338Expected<SubtargetFeatures> ELFObjectFileBase::getRISCVFeatures() const {
339 SubtargetFeatures Features;
340 unsigned PlatformFlags = getPlatformFlags();
341
342 if (PlatformFlags & ELF::EF_RISCV_RVC) {
343 Features.AddFeature(String: "zca");
344 }
345
346 RISCVAttributeParser Attributes;
347 if (Error E = getBuildAttributes(Attributes)) {
348 return std::move(E);
349 }
350
351 std::optional<StringRef> Attr =
352 Attributes.getAttributeString(tag: RISCVAttrs::ARCH);
353 if (Attr) {
354 auto ParseResult = RISCVISAInfo::parseNormalizedArchString(Arch: *Attr);
355 if (!ParseResult)
356 return ParseResult.takeError();
357 auto &ISAInfo = *ParseResult;
358
359 if (ISAInfo->getXLen() == 32)
360 Features.AddFeature(String: "64bit", Enable: false);
361 else if (ISAInfo->getXLen() == 64)
362 Features.AddFeature(String: "64bit");
363 else
364 llvm_unreachable("XLEN should be 32 or 64.");
365
366 Features.addFeaturesVector(OtherFeatures: ISAInfo->toFeatures());
367 }
368
369 return Features;
370}
371
372SubtargetFeatures ELFObjectFileBase::getLoongArchFeatures() const {
373 SubtargetFeatures Features;
374
375 switch (getPlatformFlags() & ELF::EF_LOONGARCH_ABI_MODIFIER_MASK) {
376 case ELF::EF_LOONGARCH_ABI_SOFT_FLOAT:
377 break;
378 case ELF::EF_LOONGARCH_ABI_DOUBLE_FLOAT:
379 Features.AddFeature(String: "d");
380 // D implies F according to LoongArch ISA spec.
381 [[fallthrough]];
382 case ELF::EF_LOONGARCH_ABI_SINGLE_FLOAT:
383 Features.AddFeature(String: "f");
384 break;
385 }
386
387 return Features;
388}
389
390Expected<SubtargetFeatures> ELFObjectFileBase::getFeatures() const {
391 switch (getEMachine()) {
392 case ELF::EM_MIPS:
393 return getMIPSFeatures();
394 case ELF::EM_ARM:
395 return getARMFeatures();
396 case ELF::EM_RISCV:
397 return getRISCVFeatures();
398 case ELF::EM_LOONGARCH:
399 return getLoongArchFeatures();
400 case ELF::EM_HEXAGON:
401 return getHexagonFeatures();
402 default:
403 return SubtargetFeatures();
404 }
405}
406
407std::optional<StringRef> ELFObjectFileBase::tryGetCPUName() const {
408 switch (getEMachine()) {
409 case ELF::EM_AMDGPU:
410 return getAMDGPUCPUName();
411 case ELF::EM_CUDA:
412 return getNVPTXCPUName();
413 case ELF::EM_PPC:
414 case ELF::EM_PPC64:
415 return StringRef("future");
416 case ELF::EM_BPF:
417 return StringRef("v4");
418 default:
419 return std::nullopt;
420 }
421}
422
423StringRef ELFObjectFileBase::getAMDGPUCPUName() const {
424 assert(getEMachine() == ELF::EM_AMDGPU);
425 unsigned CPU = getPlatformFlags() & ELF::EF_AMDGPU_MACH;
426
427 switch (CPU) {
428#define X(NUM, ENUM, NAME) \
429 case ELF::ENUM: \
430 return NAME;
431 AMDGPU_MACH_LIST(X)
432#undef X
433
434 default:
435 llvm_unreachable("Unknown EF_AMDGPU_MACH value");
436 }
437}
438
439StringRef ELFObjectFileBase::getNVPTXCPUName() const {
440 assert(getEMachine() == ELF::EM_CUDA);
441 unsigned SM = getEIdentABIVersion() == ELF::ELFABIVERSION_CUDA_V1
442 ? getPlatformFlags() & ELF::EF_CUDA_SM
443 : (getPlatformFlags() & ELF::EF_CUDA_SM_MASK) >>
444 ELF::EF_CUDA_SM_OFFSET;
445
446 switch (SM) {
447 // Fermi architecture.
448 case ELF::EF_CUDA_SM20:
449 return "sm_20";
450 case ELF::EF_CUDA_SM21:
451 return "sm_21";
452
453 // Kepler architecture.
454 case ELF::EF_CUDA_SM30:
455 return "sm_30";
456 case ELF::EF_CUDA_SM32:
457 return "sm_32";
458 case ELF::EF_CUDA_SM35:
459 return "sm_35";
460 case ELF::EF_CUDA_SM37:
461 return "sm_37";
462
463 // Maxwell architecture.
464 case ELF::EF_CUDA_SM50:
465 return "sm_50";
466 case ELF::EF_CUDA_SM52:
467 return "sm_52";
468 case ELF::EF_CUDA_SM53:
469 return "sm_53";
470
471 // Pascal architecture.
472 case ELF::EF_CUDA_SM60:
473 return "sm_60";
474 case ELF::EF_CUDA_SM61:
475 return "sm_61";
476 case ELF::EF_CUDA_SM62:
477 return "sm_62";
478
479 // Volta architecture.
480 case ELF::EF_CUDA_SM70:
481 return "sm_70";
482 case ELF::EF_CUDA_SM72:
483 return "sm_72";
484
485 // Turing architecture.
486 case ELF::EF_CUDA_SM75:
487 return "sm_75";
488
489 // Ampere architecture.
490 case ELF::EF_CUDA_SM80:
491 return "sm_80";
492 case ELF::EF_CUDA_SM86:
493 return "sm_86";
494 case ELF::EF_CUDA_SM87:
495 return "sm_87";
496 case ELF::EF_CUDA_SM88:
497 return "sm_88";
498
499 // Ada architecture.
500 case ELF::EF_CUDA_SM89:
501 return "sm_89";
502
503 // Hopper architecture.
504 case ELF::EF_CUDA_SM90:
505 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS_V1 ? "sm_90a"
506 : "sm_90";
507
508 // Blackwell architecture.
509 case ELF::EF_CUDA_SM100:
510 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS ? "sm_100a"
511 : "sm_100";
512 case ELF::EF_CUDA_SM101:
513 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS ? "sm_101a"
514 : "sm_101";
515 case ELF::EF_CUDA_SM103:
516 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS ? "sm_103a"
517 : "sm_103";
518 case ELF::EF_CUDA_SM110:
519 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS ? "sm_110a"
520 : "sm_110";
521
522 // Rubin architecture.
523 case ELF::EF_CUDA_SM120:
524 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS ? "sm_120a"
525 : "sm_120";
526 case ELF::EF_CUDA_SM121:
527 return getPlatformFlags() & ELF::EF_CUDA_ACCELERATORS ? "sm_121a"
528 : "sm_121";
529 default:
530 llvm_unreachable("Unknown EF_CUDA_SM value");
531 }
532}
533
534// FIXME Encode from a tablegen description or target parser.
535void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const {
536 if (TheTriple.getSubArch() != Triple::NoSubArch)
537 return;
538
539 ARMAttributeParser Attributes;
540 if (Error E = getBuildAttributes(Attributes)) {
541 // TODO Propagate Error.
542 consumeError(Err: std::move(E));
543 return;
544 }
545
546 std::string Triple;
547 // Default to ARM, but use the triple if it's been set.
548 if (TheTriple.isThumb())
549 Triple = "thumb";
550 else
551 Triple = "arm";
552
553 std::optional<unsigned> Attr =
554 Attributes.getAttributeValue(tag: ARMBuildAttrs::CPU_arch);
555 if (Attr) {
556 switch (*Attr) {
557 case ARMBuildAttrs::v4:
558 Triple += "v4";
559 break;
560 case ARMBuildAttrs::v4T:
561 Triple += "v4t";
562 break;
563 case ARMBuildAttrs::v5T:
564 Triple += "v5t";
565 break;
566 case ARMBuildAttrs::v5TE:
567 Triple += "v5te";
568 break;
569 case ARMBuildAttrs::v5TEJ:
570 Triple += "v5tej";
571 break;
572 case ARMBuildAttrs::v6:
573 Triple += "v6";
574 break;
575 case ARMBuildAttrs::v6KZ:
576 Triple += "v6kz";
577 break;
578 case ARMBuildAttrs::v6T2:
579 Triple += "v6t2";
580 break;
581 case ARMBuildAttrs::v6K:
582 Triple += "v6k";
583 break;
584 case ARMBuildAttrs::v7: {
585 std::optional<unsigned> ArchProfileAttr =
586 Attributes.getAttributeValue(tag: ARMBuildAttrs::CPU_arch_profile);
587 if (ArchProfileAttr == ARMBuildAttrs::MicroControllerProfile)
588 Triple += "v7m";
589 else
590 Triple += "v7";
591 break;
592 }
593 case ARMBuildAttrs::v6_M:
594 Triple += "v6m";
595 break;
596 case ARMBuildAttrs::v6S_M:
597 Triple += "v6sm";
598 break;
599 case ARMBuildAttrs::v7E_M:
600 Triple += "v7em";
601 break;
602 case ARMBuildAttrs::v8_A:
603 Triple += "v8a";
604 break;
605 case ARMBuildAttrs::v8_R:
606 Triple += "v8r";
607 break;
608 case ARMBuildAttrs::v8_M_Base:
609 Triple += "v8m.base";
610 break;
611 case ARMBuildAttrs::v8_M_Main:
612 Triple += "v8m.main";
613 break;
614 case ARMBuildAttrs::v8_1_M_Main:
615 Triple += "v8.1m.main";
616 break;
617 case ARMBuildAttrs::v9_A:
618 Triple += "v9a";
619 break;
620 }
621 }
622 if (!isLittleEndian())
623 Triple += "eb";
624
625 TheTriple.setArchName(Triple);
626}
627
628std::vector<ELFPltEntry>
629ELFObjectFileBase::getPltEntries(const MCSubtargetInfo &STI) const {
630 std::string Err;
631 const auto Triple = makeTriple();
632 const auto *T = TargetRegistry::lookupTarget(TheTriple: Triple, Error&: Err);
633 if (!T)
634 return {};
635 uint32_t JumpSlotReloc = 0, GlobDatReloc = 0;
636 switch (Triple.getArch()) {
637 case Triple::x86:
638 JumpSlotReloc = ELF::R_386_JUMP_SLOT;
639 GlobDatReloc = ELF::R_386_GLOB_DAT;
640 break;
641 case Triple::x86_64:
642 JumpSlotReloc = ELF::R_X86_64_JUMP_SLOT;
643 GlobDatReloc = ELF::R_X86_64_GLOB_DAT;
644 break;
645 case Triple::aarch64:
646 case Triple::aarch64_be:
647 JumpSlotReloc = ELF::R_AARCH64_JUMP_SLOT;
648 break;
649 case Triple::arm:
650 case Triple::armeb:
651 case Triple::thumb:
652 case Triple::thumbeb:
653 JumpSlotReloc = ELF::R_ARM_JUMP_SLOT;
654 break;
655 case Triple::hexagon:
656 JumpSlotReloc = ELF::R_HEX_JMP_SLOT;
657 GlobDatReloc = ELF::R_HEX_GLOB_DAT;
658 break;
659 case Triple::riscv32:
660 case Triple::riscv64:
661 JumpSlotReloc = ELF::R_RISCV_JUMP_SLOT;
662 break;
663 default:
664 return {};
665 }
666 std::unique_ptr<const MCInstrInfo> MII(T->createMCInstrInfo());
667 std::unique_ptr<const MCInstrAnalysis> MIA(
668 T->createMCInstrAnalysis(Info: MII.get()));
669 if (!MIA)
670 return {};
671 std::vector<std::pair<uint64_t, uint64_t>> PltEntries;
672 std::optional<SectionRef> RelaPlt, RelaDyn;
673 uint64_t GotBaseVA = 0;
674 for (const SectionRef &Section : sections()) {
675 Expected<StringRef> NameOrErr = Section.getName();
676 if (!NameOrErr) {
677 consumeError(Err: NameOrErr.takeError());
678 continue;
679 }
680 StringRef Name = *NameOrErr;
681
682 if (Name == ".rela.plt" || Name == ".rel.plt") {
683 RelaPlt = Section;
684 } else if (Name == ".rela.dyn" || Name == ".rel.dyn") {
685 RelaDyn = Section;
686 } else if (Name == ".got.plt") {
687 GotBaseVA = Section.getAddress();
688 } else if (Name == ".plt" || Name == ".plt.got") {
689 Expected<StringRef> PltContents = Section.getContents();
690 if (!PltContents) {
691 consumeError(Err: PltContents.takeError());
692 return {};
693 }
694 llvm::append_range(
695 C&: PltEntries,
696 R: MIA->findPltEntries(PltSectionVA: Section.getAddress(),
697 PltContents: arrayRefFromStringRef(Input: *PltContents), STI));
698 }
699 }
700
701 // Build a map from GOT entry virtual address to PLT entry virtual address.
702 DenseMap<uint64_t, uint64_t> GotToPlt;
703 for (auto [Plt, GotPlt] : PltEntries) {
704 uint64_t GotPltEntry = GotPlt;
705 // An x86-32 PIC PLT uses jmp DWORD PTR [ebx-offset]. Add
706 // _GLOBAL_OFFSET_TABLE_ (EBX) to get the .got.plt (or .got) entry address.
707 // See X86MCTargetDesc.cpp:findPltEntries for the 1 << 32 bit.
708 if (GotPltEntry & (uint64_t(1) << 32) && getEMachine() == ELF::EM_386)
709 GotPltEntry = static_cast<int32_t>(GotPltEntry) + GotBaseVA;
710 GotToPlt.insert(KV: std::make_pair(x&: GotPltEntry, y&: Plt));
711 }
712
713 // Find the relocations in the dynamic relocation table that point to
714 // locations in the GOT for which we know the corresponding PLT entry.
715 std::vector<ELFPltEntry> Result;
716 auto handleRels = [&](iterator_range<relocation_iterator> Rels,
717 uint32_t RelType, StringRef PltSec) {
718 for (const auto &R : Rels) {
719 if (R.getType() != RelType)
720 continue;
721 auto PltEntryIter = GotToPlt.find(Val: R.getOffset());
722 if (PltEntryIter != GotToPlt.end()) {
723 symbol_iterator Sym = R.getSymbol();
724 if (Sym == symbol_end())
725 Result.push_back(
726 x: ELFPltEntry{.Section: PltSec, .Symbol: std::nullopt, .Address: PltEntryIter->second});
727 else
728 Result.push_back(x: ELFPltEntry{.Section: PltSec, .Symbol: Sym->getRawDataRefImpl(),
729 .Address: PltEntryIter->second});
730 }
731 }
732 };
733
734 if (RelaPlt)
735 handleRels(RelaPlt->relocations(), JumpSlotReloc, ".plt");
736
737 // If a symbol needing a PLT entry also needs a GLOB_DAT relocation, GNU ld's
738 // x86 port places the PLT entry in the .plt.got section.
739 if (RelaDyn)
740 handleRels(RelaDyn->relocations(), GlobDatReloc, ".plt.got");
741
742 return Result;
743}
744
745template <class ELFT>
746Expected<std::vector<BBAddrMap>> static readBBAddrMapImpl(
747 const ELFFile<ELFT> &EF, std::optional<unsigned> TextSectionIndex,
748 std::vector<PGOAnalysisMap> *PGOAnalyses) {
749 using Elf_Shdr = typename ELFT::Shdr;
750 bool IsRelocatable = EF.getHeader().e_type == ELF::ET_REL;
751 std::vector<BBAddrMap> BBAddrMaps;
752 if (PGOAnalyses)
753 PGOAnalyses->clear();
754
755 const auto &Sections = cantFail(EF.sections());
756 auto IsMatch = [&](const Elf_Shdr &Sec) -> Expected<bool> {
757 if (Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP)
758 return false;
759 if (!TextSectionIndex)
760 return true;
761 Expected<const Elf_Shdr *> TextSecOrErr = EF.getSection(Sec.sh_link);
762 if (!TextSecOrErr)
763 return createError("unable to get the linked-to section for " +
764 describe(EF, Sec) + ": " +
765 toString(TextSecOrErr.takeError()));
766 assert(*TextSecOrErr >= Sections.begin() &&
767 "Text section pointer outside of bounds");
768 if (*TextSectionIndex !=
769 (unsigned)std::distance(Sections.begin(), *TextSecOrErr))
770 return false;
771 return true;
772 };
773
774 Expected<MapVector<const Elf_Shdr *, const Elf_Shdr *>> SectionRelocMapOrErr =
775 EF.getSectionAndRelocations(IsMatch);
776 if (!SectionRelocMapOrErr)
777 return SectionRelocMapOrErr.takeError();
778
779 for (auto const &[Sec, RelocSec] : *SectionRelocMapOrErr) {
780 if (IsRelocatable && !RelocSec)
781 return createError("unable to get relocation section for " +
782 describe(EF, *Sec));
783 Expected<std::vector<BBAddrMap>> BBAddrMapOrErr =
784 EF.decodeBBAddrMap(*Sec, RelocSec, PGOAnalyses);
785 if (!BBAddrMapOrErr) {
786 if (PGOAnalyses)
787 PGOAnalyses->clear();
788 return createError(Err: "unable to read BB addr map section: " +
789 toString(E: BBAddrMapOrErr.takeError()));
790 }
791 std::move(first: BBAddrMapOrErr->begin(), last: BBAddrMapOrErr->end(),
792 result: std::back_inserter(x&: BBAddrMaps));
793 }
794 if (PGOAnalyses)
795 assert(PGOAnalyses->size() == BBAddrMaps.size() &&
796 "The same number of BBAddrMaps and PGOAnalysisMaps should be "
797 "returned when PGO information is requested");
798 return BBAddrMaps;
799}
800
801template <class ELFT>
802static Expected<std::vector<VersionEntry>>
803readDynsymVersionsImpl(const ELFFile<ELFT> &EF,
804 ELFObjectFileBase::elf_symbol_iterator_range Symbols) {
805 using Elf_Shdr = typename ELFT::Shdr;
806 const Elf_Shdr *VerSec = nullptr;
807 const Elf_Shdr *VerNeedSec = nullptr;
808 const Elf_Shdr *VerDefSec = nullptr;
809 // The user should ensure sections() can't fail here.
810 for (const Elf_Shdr &Sec : cantFail(EF.sections())) {
811 if (Sec.sh_type == ELF::SHT_GNU_versym)
812 VerSec = &Sec;
813 else if (Sec.sh_type == ELF::SHT_GNU_verdef)
814 VerDefSec = &Sec;
815 else if (Sec.sh_type == ELF::SHT_GNU_verneed)
816 VerNeedSec = &Sec;
817 }
818 if (!VerSec)
819 return std::vector<VersionEntry>();
820
821 Expected<SmallVector<std::optional<VersionEntry>, 0>> MapOrErr =
822 EF.loadVersionMap(VerNeedSec, VerDefSec);
823 if (!MapOrErr)
824 return MapOrErr.takeError();
825
826 std::vector<VersionEntry> Ret;
827 size_t I = 0;
828 for (const ELFSymbolRef &Sym : Symbols) {
829 ++I;
830 Expected<const typename ELFT::Versym *> VerEntryOrErr =
831 EF.template getEntry<typename ELFT::Versym>(*VerSec, I);
832 if (!VerEntryOrErr)
833 return createError("unable to read an entry with index " + Twine(I) +
834 " from " + describe(EF, *VerSec) + ": " +
835 toString(VerEntryOrErr.takeError()));
836
837 Expected<uint32_t> FlagsOrErr = Sym.getFlags();
838 if (!FlagsOrErr)
839 return createError(Err: "unable to read flags for symbol with index " +
840 Twine(I) + ": " + toString(E: FlagsOrErr.takeError()));
841
842 bool IsDefault;
843 Expected<StringRef> VerOrErr = EF.getSymbolVersionByIndex(
844 (*VerEntryOrErr)->vs_index, IsDefault, *MapOrErr,
845 (*FlagsOrErr) & SymbolRef::SF_Undefined);
846 if (!VerOrErr)
847 return createError("unable to get a version for entry " + Twine(I) +
848 " of " + describe(EF, *VerSec) + ": " +
849 toString(E: VerOrErr.takeError()));
850
851 Ret.push_back(x: {.Name: (*VerOrErr).str(), .IsVerDef: IsDefault});
852 }
853
854 return Ret;
855}
856
857Expected<std::vector<VersionEntry>>
858ELFObjectFileBase::readDynsymVersions() const {
859 elf_symbol_iterator_range Symbols = getDynamicSymbolIterators();
860 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(Val: this))
861 return readDynsymVersionsImpl(EF: Obj->getELFFile(), Symbols);
862 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(Val: this))
863 return readDynsymVersionsImpl(EF: Obj->getELFFile(), Symbols);
864 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(Val: this))
865 return readDynsymVersionsImpl(EF: Obj->getELFFile(), Symbols);
866 return readDynsymVersionsImpl(EF: cast<ELF64BEObjectFile>(Val: this)->getELFFile(),
867 Symbols);
868}
869
870Expected<std::vector<BBAddrMap>> ELFObjectFileBase::readBBAddrMap(
871 std::optional<unsigned> TextSectionIndex,
872 std::vector<PGOAnalysisMap> *PGOAnalyses) const {
873 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(Val: this))
874 return readBBAddrMapImpl(EF: Obj->getELFFile(), TextSectionIndex, PGOAnalyses);
875 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(Val: this))
876 return readBBAddrMapImpl(EF: Obj->getELFFile(), TextSectionIndex, PGOAnalyses);
877 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(Val: this))
878 return readBBAddrMapImpl(EF: Obj->getELFFile(), TextSectionIndex, PGOAnalyses);
879 return readBBAddrMapImpl(EF: cast<ELF64BEObjectFile>(Val: this)->getELFFile(),
880 TextSectionIndex, PGOAnalyses);
881}
882
883StringRef ELFObjectFileBase::getCrelDecodeProblem(SectionRef Sec) const {
884 auto Data = Sec.getRawDataRefImpl();
885 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(Val: this))
886 return Obj->getCrelDecodeProblem(Sec: Data);
887 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(Val: this))
888 return Obj->getCrelDecodeProblem(Sec: Data);
889 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(Val: this))
890 return Obj->getCrelDecodeProblem(Sec: Data);
891 return cast<ELF64BEObjectFile>(Val: this)->getCrelDecodeProblem(Sec: Data);
892}
893