1//===- Driver.cpp ---------------------------------------------------------===//
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// The driver drives the entire linking process. It is responsible for
10// parsing command line options and doing whatever it is instructed to do.
11//
12// One notable thing in the LLD's driver when compared to other linkers is
13// that the LLD's driver is agnostic on the host operating system.
14// Other linkers usually have implicit default values (such as a dynamic
15// linker path or library paths) for each host OS.
16//
17// I don't think implicit default values are useful because they are
18// usually explicitly specified by the compiler ctx.driver. They can even
19// be harmful when you are doing cross-linking. Therefore, in LLD, we
20// simply trust the compiler driver to pass all required options and
21// don't try to make effort on our side.
22//
23//===----------------------------------------------------------------------===//
24
25#include "Driver.h"
26#include "Config.h"
27#include "ICF.h"
28#include "InputFiles.h"
29#include "InputSection.h"
30#include "LTO.h"
31#include "LinkerScript.h"
32#include "MarkLive.h"
33#include "OutputSections.h"
34#include "ScriptParser.h"
35#include "SymbolTable.h"
36#include "Symbols.h"
37#include "SyntheticSections.h"
38#include "Target.h"
39#include "Writer.h"
40#include "lld/Common/Args.h"
41#include "lld/Common/CommonLinkerContext.h"
42#include "lld/Common/Driver.h"
43#include "lld/Common/ErrorHandler.h"
44#include "lld/Common/Filesystem.h"
45#include "lld/Common/Memory.h"
46#include "lld/Common/Strings.h"
47#include "lld/Common/TargetOptionsCommandFlags.h"
48#include "lld/Common/Version.h"
49#include "llvm/ADT/STLExtras.h"
50#include "llvm/ADT/SetVector.h"
51#include "llvm/ADT/StringExtras.h"
52#include "llvm/ADT/StringSwitch.h"
53#include "llvm/Config/llvm-config.h"
54#include "llvm/LTO/LTO.h"
55#include "llvm/Object/Archive.h"
56#include "llvm/Object/IRObjectFile.h"
57#include "llvm/Remarks/HotnessThresholdParser.h"
58#include "llvm/Support/CommandLine.h"
59#include "llvm/Support/Compression.h"
60#include "llvm/Support/FileSystem.h"
61#include "llvm/Support/GlobPattern.h"
62#include "llvm/Support/LEB128.h"
63#include "llvm/Support/Parallel.h"
64#include "llvm/Support/Path.h"
65#include "llvm/Support/TarWriter.h"
66#include "llvm/Support/TargetSelect.h"
67#include "llvm/Support/TimeProfiler.h"
68#include "llvm/Support/raw_ostream.h"
69#include <cstdlib>
70#include <tuple>
71#include <utility>
72
73using namespace llvm;
74using namespace llvm::ELF;
75using namespace llvm::object;
76using namespace llvm::sys;
77using namespace llvm::support;
78using namespace lld;
79using namespace lld::elf;
80
81ConfigWrapper elf::config;
82Ctx elf::ctx;
83
84static void setConfigs(opt::InputArgList &args);
85static void readConfigs(opt::InputArgList &args);
86
87void elf::errorOrWarn(const Twine &msg) {
88 if (config->noinhibitExec)
89 warn(msg);
90 else
91 error(msg);
92}
93
94void Ctx::reset() {
95 driver = LinkerDriver();
96 memoryBuffers.clear();
97 objectFiles.clear();
98 sharedFiles.clear();
99 binaryFiles.clear();
100 bitcodeFiles.clear();
101 lazyBitcodeFiles.clear();
102 inputSections.clear();
103 ehInputSections.clear();
104 duplicates.clear();
105 nonPrevailingSyms.clear();
106 whyExtractRecords.clear();
107 backwardReferences.clear();
108 auxiliaryFiles.clear();
109 internalFile = nullptr;
110 hasSympart.store(i: false, m: std::memory_order_relaxed);
111 hasTlsIe.store(i: false, m: std::memory_order_relaxed);
112 needsTlsLd.store(i: false, m: std::memory_order_relaxed);
113 scriptSymOrderCounter = 1;
114 scriptSymOrder.clear();
115 ltoAllVtablesHaveTypeInfos = false;
116}
117
118llvm::raw_fd_ostream Ctx::openAuxiliaryFile(llvm::StringRef filename,
119 std::error_code &ec) {
120 using namespace llvm::sys::fs;
121 OpenFlags flags =
122 auxiliaryFiles.insert(V: filename).second ? OF_None : OF_Append;
123 return {filename, ec, flags};
124}
125
126namespace lld {
127namespace elf {
128bool link(ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
129 llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput) {
130 // This driver-specific context will be freed later by unsafeLldMain().
131 auto *ctx = new CommonLinkerContext;
132
133 ctx->e.initialize(stdoutOS, stderrOS, exitEarly, disableOutput);
134 ctx->e.cleanupCallback = []() {
135 elf::ctx.reset();
136 symtab = SymbolTable();
137
138 outputSections.clear();
139 symAux.clear();
140
141 tar = nullptr;
142 in.reset();
143
144 partitions.clear();
145 partitions.emplace_back();
146
147 SharedFile::vernauxNum = 0;
148 };
149 ctx->e.logName = args::getFilenameWithoutExe(path: args[0]);
150 ctx->e.errorLimitExceededMsg = "too many errors emitted, stopping now (use "
151 "--error-limit=0 to see all errors)";
152
153 config = ConfigWrapper();
154 script = ScriptWrapper();
155
156 symAux.emplace_back();
157
158 partitions.clear();
159 partitions.emplace_back();
160
161 config->progName = args[0];
162
163 elf::ctx.driver.linkerMain(args);
164
165 return errorCount() == 0;
166}
167} // namespace elf
168} // namespace lld
169
170// Parses a linker -m option.
171static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(StringRef emul) {
172 uint8_t osabi = 0;
173 StringRef s = emul;
174 if (s.ends_with(Suffix: "_fbsd")) {
175 s = s.drop_back(N: 5);
176 osabi = ELFOSABI_FREEBSD;
177 }
178
179 std::pair<ELFKind, uint16_t> ret =
180 StringSwitch<std::pair<ELFKind, uint16_t>>(s)
181 .Cases(S0: "aarch64elf", S1: "aarch64linux", Value: {ELF64LEKind, EM_AARCH64})
182 .Cases(S0: "aarch64elfb", S1: "aarch64linuxb", Value: {ELF64BEKind, EM_AARCH64})
183 .Cases(S0: "armelf", S1: "armelf_linux_eabi", Value: {ELF32LEKind, EM_ARM})
184 .Cases(S0: "armelfb", S1: "armelfb_linux_eabi", Value: {ELF32BEKind, EM_ARM})
185 .Case(S: "elf32_x86_64", Value: {ELF32LEKind, EM_X86_64})
186 .Cases(S0: "elf32btsmip", S1: "elf32btsmipn32", Value: {ELF32BEKind, EM_MIPS})
187 .Cases(S0: "elf32ltsmip", S1: "elf32ltsmipn32", Value: {ELF32LEKind, EM_MIPS})
188 .Case(S: "elf32lriscv", Value: {ELF32LEKind, EM_RISCV})
189 .Cases(S0: "elf32ppc", S1: "elf32ppclinux", Value: {ELF32BEKind, EM_PPC})
190 .Cases(S0: "elf32lppc", S1: "elf32lppclinux", Value: {ELF32LEKind, EM_PPC})
191 .Case(S: "elf32loongarch", Value: {ELF32LEKind, EM_LOONGARCH})
192 .Case(S: "elf64btsmip", Value: {ELF64BEKind, EM_MIPS})
193 .Case(S: "elf64ltsmip", Value: {ELF64LEKind, EM_MIPS})
194 .Case(S: "elf64lriscv", Value: {ELF64LEKind, EM_RISCV})
195 .Case(S: "elf64ppc", Value: {ELF64BEKind, EM_PPC64})
196 .Case(S: "elf64lppc", Value: {ELF64LEKind, EM_PPC64})
197 .Cases(S0: "elf_amd64", S1: "elf_x86_64", Value: {ELF64LEKind, EM_X86_64})
198 .Case(S: "elf_i386", Value: {ELF32LEKind, EM_386})
199 .Case(S: "elf_iamcu", Value: {ELF32LEKind, EM_IAMCU})
200 .Case(S: "elf64_sparc", Value: {ELF64BEKind, EM_SPARCV9})
201 .Case(S: "msp430elf", Value: {ELF32LEKind, EM_MSP430})
202 .Case(S: "elf64_amdgpu", Value: {ELF64LEKind, EM_AMDGPU})
203 .Case(S: "elf64loongarch", Value: {ELF64LEKind, EM_LOONGARCH})
204 .Case(S: "elf64_s390", Value: {ELF64BEKind, EM_S390})
205 .Case(S: "hexagonelf", Value: {ELF32LEKind, EM_HEXAGON})
206 .Default(Value: {ELFNoneKind, EM_NONE});
207
208 if (ret.first == ELFNoneKind)
209 error(msg: "unknown emulation: " + emul);
210 if (ret.second == EM_MSP430)
211 osabi = ELFOSABI_STANDALONE;
212 else if (ret.second == EM_AMDGPU)
213 osabi = ELFOSABI_AMDGPU_HSA;
214 return std::make_tuple(args&: ret.first, args&: ret.second, args&: osabi);
215}
216
217// Returns slices of MB by parsing MB as an archive file.
218// Each slice consists of a member file in the archive.
219std::vector<std::pair<MemoryBufferRef, uint64_t>> static getArchiveMembers(
220 MemoryBufferRef mb) {
221 std::unique_ptr<Archive> file =
222 CHECK(Archive::create(mb),
223 mb.getBufferIdentifier() + ": failed to parse archive");
224
225 std::vector<std::pair<MemoryBufferRef, uint64_t>> v;
226 Error err = Error::success();
227 bool addToTar = file->isThin() && tar;
228 for (const Archive::Child &c : file->children(Err&: err)) {
229 MemoryBufferRef mbref =
230 CHECK(c.getMemoryBufferRef(),
231 mb.getBufferIdentifier() +
232 ": could not get the buffer for a child of the archive");
233 if (addToTar)
234 tar->append(Path: relativeToRoot(path: check(e: c.getFullName())), Data: mbref.getBuffer());
235 v.push_back(x: std::make_pair(x&: mbref, y: c.getChildOffset()));
236 }
237 if (err)
238 fatal(msg: mb.getBufferIdentifier() + ": Archive::children failed: " +
239 toString(E: std::move(err)));
240
241 // Take ownership of memory buffers created for members of thin archives.
242 std::vector<std::unique_ptr<MemoryBuffer>> mbs = file->takeThinBuffers();
243 std::move(first: mbs.begin(), last: mbs.end(), result: std::back_inserter(x&: ctx.memoryBuffers));
244
245 return v;
246}
247
248static bool isBitcode(MemoryBufferRef mb) {
249 return identify_magic(magic: mb.getBuffer()) == llvm::file_magic::bitcode;
250}
251
252bool LinkerDriver::tryAddFatLTOFile(MemoryBufferRef mb, StringRef archiveName,
253 uint64_t offsetInArchive, bool lazy) {
254 if (!config->fatLTOObjects)
255 return false;
256 Expected<MemoryBufferRef> fatLTOData =
257 IRObjectFile::findBitcodeInMemBuffer(Object: mb);
258 if (errorToBool(Err: fatLTOData.takeError()))
259 return false;
260 files.push_back(
261 x: make<BitcodeFile>(args&: *fatLTOData, args&: archiveName, args&: offsetInArchive, args&: lazy));
262 return true;
263}
264
265// Opens a file and create a file object. Path has to be resolved already.
266void LinkerDriver::addFile(StringRef path, bool withLOption) {
267 using namespace sys::fs;
268
269 std::optional<MemoryBufferRef> buffer = readFile(path);
270 if (!buffer)
271 return;
272 MemoryBufferRef mbref = *buffer;
273
274 if (config->formatBinary) {
275 files.push_back(x: make<BinaryFile>(args&: mbref));
276 return;
277 }
278
279 switch (identify_magic(magic: mbref.getBuffer())) {
280 case file_magic::unknown:
281 readLinkerScript(mb: mbref);
282 return;
283 case file_magic::archive: {
284 auto members = getArchiveMembers(mb: mbref);
285 if (inWholeArchive) {
286 for (const std::pair<MemoryBufferRef, uint64_t> &p : members) {
287 if (isBitcode(mb: p.first))
288 files.push_back(x: make<BitcodeFile>(args: p.first, args&: path, args: p.second, args: false));
289 else if (!tryAddFatLTOFile(mb: p.first, archiveName: path, offsetInArchive: p.second, lazy: false))
290 files.push_back(x: createObjFile(mb: p.first, archiveName: path));
291 }
292 return;
293 }
294
295 archiveFiles.emplace_back(Args&: path, Args: members.size());
296
297 // Handle archives and --start-lib/--end-lib using the same code path. This
298 // scans all the ELF relocatable object files and bitcode files in the
299 // archive rather than just the index file, with the benefit that the
300 // symbols are only loaded once. For many projects archives see high
301 // utilization rates and it is a net performance win. --start-lib scans
302 // symbols in the same order that llvm-ar adds them to the index, so in the
303 // common case the semantics are identical. If the archive symbol table was
304 // created in a different order, or is incomplete, this strategy has
305 // different semantics. Such output differences are considered user error.
306 //
307 // All files within the archive get the same group ID to allow mutual
308 // references for --warn-backrefs.
309 bool saved = InputFile::isInGroup;
310 InputFile::isInGroup = true;
311 for (const std::pair<MemoryBufferRef, uint64_t> &p : members) {
312 auto magic = identify_magic(magic: p.first.getBuffer());
313 if (magic == file_magic::elf_relocatable) {
314 if (!tryAddFatLTOFile(mb: p.first, archiveName: path, offsetInArchive: p.second, lazy: true))
315 files.push_back(x: createObjFile(mb: p.first, archiveName: path, lazy: true));
316 } else if (magic == file_magic::bitcode)
317 files.push_back(x: make<BitcodeFile>(args: p.first, args&: path, args: p.second, args: true));
318 else
319 warn(msg: path + ": archive member '" + p.first.getBufferIdentifier() +
320 "' is neither ET_REL nor LLVM bitcode");
321 }
322 InputFile::isInGroup = saved;
323 if (!saved)
324 ++InputFile::nextGroupId;
325 return;
326 }
327 case file_magic::elf_shared_object: {
328 if (config->isStatic) {
329 error(msg: "attempted static link of dynamic object " + path);
330 return;
331 }
332
333 // Shared objects are identified by soname. soname is (if specified)
334 // DT_SONAME and falls back to filename. If a file was specified by -lfoo,
335 // the directory part is ignored. Note that path may be a temporary and
336 // cannot be stored into SharedFile::soName.
337 path = mbref.getBufferIdentifier();
338 auto *f =
339 make<SharedFile>(args&: mbref, args: withLOption ? path::filename(path) : path);
340 f->init();
341 files.push_back(x: f);
342 return;
343 }
344 case file_magic::bitcode:
345 files.push_back(x: make<BitcodeFile>(args&: mbref, args: "", args: 0, args&: inLib));
346 break;
347 case file_magic::elf_relocatable:
348 if (!tryAddFatLTOFile(mb: mbref, archiveName: "", offsetInArchive: 0, lazy: inLib))
349 files.push_back(x: createObjFile(mb: mbref, archiveName: "", lazy: inLib));
350 break;
351 default:
352 error(msg: path + ": unknown file type");
353 }
354}
355
356// Add a given library by searching it from input search paths.
357void LinkerDriver::addLibrary(StringRef name) {
358 if (std::optional<std::string> path = searchLibrary(path: name))
359 addFile(path: saver().save(S: *path), /*withLOption=*/true);
360 else
361 error(msg: "unable to find library -l" + name, tag: ErrorTag::LibNotFound, args: {name});
362}
363
364// This function is called on startup. We need this for LTO since
365// LTO calls LLVM functions to compile bitcode files to native code.
366// Technically this can be delayed until we read bitcode files, but
367// we don't bother to do lazily because the initialization is fast.
368static void initLLVM() {
369 InitializeAllTargets();
370 InitializeAllTargetMCs();
371 InitializeAllAsmPrinters();
372 InitializeAllAsmParsers();
373}
374
375// Some command line options or some combinations of them are not allowed.
376// This function checks for such errors.
377static void checkOptions() {
378 // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
379 // table which is a relatively new feature.
380 if (config->emachine == EM_MIPS && config->gnuHash)
381 error(msg: "the .gnu.hash section is not compatible with the MIPS target");
382
383 if (config->emachine == EM_ARM) {
384 if (!config->cmseImplib) {
385 if (!config->cmseInputLib.empty())
386 error(msg: "--in-implib may not be used without --cmse-implib");
387 if (!config->cmseOutputLib.empty())
388 error(msg: "--out-implib may not be used without --cmse-implib");
389 }
390 } else {
391 if (config->cmseImplib)
392 error(msg: "--cmse-implib is only supported on ARM targets");
393 if (!config->cmseInputLib.empty())
394 error(msg: "--in-implib is only supported on ARM targets");
395 if (!config->cmseOutputLib.empty())
396 error(msg: "--out-implib is only supported on ARM targets");
397 }
398
399 if (config->fixCortexA53Errata843419 && config->emachine != EM_AARCH64)
400 error(msg: "--fix-cortex-a53-843419 is only supported on AArch64 targets");
401
402 if (config->fixCortexA8 && config->emachine != EM_ARM)
403 error(msg: "--fix-cortex-a8 is only supported on ARM targets");
404
405 if (config->armBe8 && config->emachine != EM_ARM)
406 error(msg: "--be8 is only supported on ARM targets");
407
408 if (config->fixCortexA8 && !config->isLE)
409 error(msg: "--fix-cortex-a8 is not supported on big endian targets");
410
411 if (config->tocOptimize && config->emachine != EM_PPC64)
412 error(msg: "--toc-optimize is only supported on PowerPC64 targets");
413
414 if (config->pcRelOptimize && config->emachine != EM_PPC64)
415 error(msg: "--pcrel-optimize is only supported on PowerPC64 targets");
416
417 if (config->relaxGP && config->emachine != EM_RISCV)
418 error(msg: "--relax-gp is only supported on RISC-V targets");
419
420 if (config->pie && config->shared)
421 error(msg: "-shared and -pie may not be used together");
422
423 if (!config->shared && !config->filterList.empty())
424 error(msg: "-F may not be used without -shared");
425
426 if (!config->shared && !config->auxiliaryList.empty())
427 error(msg: "-f may not be used without -shared");
428
429 if (config->strip == StripPolicy::All && config->emitRelocs)
430 error(msg: "--strip-all and --emit-relocs may not be used together");
431
432 if (config->zText && config->zIfuncNoplt)
433 error(msg: "-z text and -z ifunc-noplt may not be used together");
434
435 if (config->relocatable) {
436 if (config->shared)
437 error(msg: "-r and -shared may not be used together");
438 if (config->gdbIndex)
439 error(msg: "-r and --gdb-index may not be used together");
440 if (config->icf != ICFLevel::None)
441 error(msg: "-r and --icf may not be used together");
442 if (config->pie)
443 error(msg: "-r and -pie may not be used together");
444 if (config->exportDynamic)
445 error(msg: "-r and --export-dynamic may not be used together");
446 if (config->debugNames)
447 error(msg: "-r and --debug-names may not be used together");
448 }
449
450 if (config->executeOnly) {
451 if (config->emachine != EM_AARCH64)
452 error(msg: "--execute-only is only supported on AArch64 targets");
453
454 if (config->singleRoRx && !script->hasSectionsCommand)
455 error(msg: "--execute-only and --no-rosegment cannot be used together");
456 }
457
458 if (config->zRetpolineplt && config->zForceIbt)
459 error(msg: "-z force-ibt may not be used with -z retpolineplt");
460
461 if (config->emachine != EM_AARCH64) {
462 if (config->zPacPlt)
463 error(msg: "-z pac-plt only supported on AArch64");
464 if (config->zForceBti)
465 error(msg: "-z force-bti only supported on AArch64");
466 if (config->zBtiReport != "none")
467 error(msg: "-z bti-report only supported on AArch64");
468 if (config->zPauthReport != "none")
469 error(msg: "-z pauth-report only supported on AArch64");
470 if (config->zGcsReport != "none")
471 error(msg: "-z gcs-report only supported on AArch64");
472 if (config->zGcs != GcsPolicy::Implicit)
473 error(msg: "-z gcs only supported on AArch64");
474 }
475
476 if (config->emachine != EM_386 && config->emachine != EM_X86_64 &&
477 config->zCetReport != "none")
478 error(msg: "-z cet-report only supported on X86 and X86_64");
479}
480
481static const char *getReproduceOption(opt::InputArgList &args) {
482 if (auto *arg = args.getLastArg(Ids: OPT_reproduce))
483 return arg->getValue();
484 return getenv(name: "LLD_REPRODUCE");
485}
486
487static bool hasZOption(opt::InputArgList &args, StringRef key) {
488 bool ret = false;
489 for (auto *arg : args.filtered(Ids: OPT_z))
490 if (key == arg->getValue()) {
491 ret = true;
492 arg->claim();
493 }
494 return ret;
495}
496
497static bool getZFlag(opt::InputArgList &args, StringRef k1, StringRef k2,
498 bool defaultValue) {
499 for (auto *arg : args.filtered(Ids: OPT_z)) {
500 StringRef v = arg->getValue();
501 if (k1 == v)
502 defaultValue = true;
503 else if (k2 == v)
504 defaultValue = false;
505 else
506 continue;
507 arg->claim();
508 }
509 return defaultValue;
510}
511
512static SeparateSegmentKind getZSeparate(opt::InputArgList &args) {
513 auto ret = SeparateSegmentKind::None;
514 for (auto *arg : args.filtered(Ids: OPT_z)) {
515 StringRef v = arg->getValue();
516 if (v == "noseparate-code")
517 ret = SeparateSegmentKind::None;
518 else if (v == "separate-code")
519 ret = SeparateSegmentKind::Code;
520 else if (v == "separate-loadable-segments")
521 ret = SeparateSegmentKind::Loadable;
522 else
523 continue;
524 arg->claim();
525 }
526 return ret;
527}
528
529static GnuStackKind getZGnuStack(opt::InputArgList &args) {
530 auto ret = GnuStackKind::NoExec;
531 for (auto *arg : args.filtered(Ids: OPT_z)) {
532 StringRef v = arg->getValue();
533 if (v == "execstack")
534 ret = GnuStackKind::Exec;
535 else if (v == "noexecstack")
536 ret = GnuStackKind::NoExec;
537 else if (v == "nognustack")
538 ret = GnuStackKind::None;
539 else
540 continue;
541 arg->claim();
542 }
543 return ret;
544}
545
546static uint8_t getZStartStopVisibility(opt::InputArgList &args) {
547 uint8_t ret = STV_PROTECTED;
548 for (auto *arg : args.filtered(Ids: OPT_z)) {
549 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
550 if (kv.first == "start-stop-visibility") {
551 arg->claim();
552 if (kv.second == "default")
553 ret = STV_DEFAULT;
554 else if (kv.second == "internal")
555 ret = STV_INTERNAL;
556 else if (kv.second == "hidden")
557 ret = STV_HIDDEN;
558 else if (kv.second == "protected")
559 ret = STV_PROTECTED;
560 else
561 error(msg: "unknown -z start-stop-visibility= value: " +
562 StringRef(kv.second));
563 }
564 }
565 return ret;
566}
567
568static GcsPolicy getZGcs(opt::InputArgList &args) {
569 GcsPolicy ret = GcsPolicy::Implicit;
570 for (auto *arg : args.filtered(Ids: OPT_z)) {
571 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
572 if (kv.first == "gcs") {
573 arg->claim();
574 if (kv.second == "implicit")
575 ret = GcsPolicy::Implicit;
576 else if (kv.second == "never")
577 ret = GcsPolicy::Never;
578 else if (kv.second == "always")
579 ret = GcsPolicy::Always;
580 else
581 error(msg: "unknown -z gcs= value: " + kv.second);
582 }
583 }
584 return ret;
585}
586
587// Report a warning for an unknown -z option.
588static void checkZOptions(opt::InputArgList &args) {
589 // This function is called before getTarget(), when certain options are not
590 // initialized yet. Claim them here.
591 args::getZOptionValue(args, id: OPT_z, key: "max-page-size", Default: 0);
592 args::getZOptionValue(args, id: OPT_z, key: "common-page-size", Default: 0);
593 getZFlag(args, k1: "rel", k2: "rela", defaultValue: false);
594 for (auto *arg : args.filtered(Ids: OPT_z))
595 if (!arg->isClaimed())
596 warn(msg: "unknown -z value: " + StringRef(arg->getValue()));
597}
598
599constexpr const char *saveTempsValues[] = {
600 "resolution", "preopt", "promote", "internalize", "import",
601 "opt", "precodegen", "prelink", "combinedindex"};
602
603void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
604 ELFOptTable parser;
605 opt::InputArgList args = parser.parse(argv: argsArr.slice(N: 1));
606
607 // Interpret these flags early because error()/warn() depend on them.
608 errorHandler().errorLimit = args::getInteger(args, key: OPT_error_limit, Default: 20);
609 errorHandler().fatalWarnings =
610 args.hasFlag(Pos: OPT_fatal_warnings, Neg: OPT_no_fatal_warnings, Default: false) &&
611 !args.hasArg(Ids: OPT_no_warnings);
612 errorHandler().suppressWarnings = args.hasArg(Ids: OPT_no_warnings);
613
614 // Handle -help
615 if (args.hasArg(Ids: OPT_help)) {
616 printHelp();
617 return;
618 }
619
620 // Handle -v or -version.
621 //
622 // A note about "compatible with GNU linkers" message: this is a hack for
623 // scripts generated by GNU Libtool up to 2021-10 to recognize LLD as
624 // a GNU compatible linker. See
625 // <https://lists.gnu.org/archive/html/libtool/2017-01/msg00007.html>.
626 //
627 // This is somewhat ugly hack, but in reality, we had no choice other
628 // than doing this. Considering the very long release cycle of Libtool,
629 // it is not easy to improve it to recognize LLD as a GNU compatible
630 // linker in a timely manner. Even if we can make it, there are still a
631 // lot of "configure" scripts out there that are generated by old version
632 // of Libtool. We cannot convince every software developer to migrate to
633 // the latest version and re-generate scripts. So we have this hack.
634 if (args.hasArg(Ids: OPT_v) || args.hasArg(Ids: OPT_version))
635 message(msg: getLLDVersion() + " (compatible with GNU linkers)");
636
637 if (const char *path = getReproduceOption(args)) {
638 // Note that --reproduce is a debug option so you can ignore it
639 // if you are trying to understand the whole picture of the code.
640 Expected<std::unique_ptr<TarWriter>> errOrWriter =
641 TarWriter::create(OutputPath: path, BaseDir: path::stem(path));
642 if (errOrWriter) {
643 tar = std::move(*errOrWriter);
644 tar->append(Path: "response.txt", Data: createResponseFile(args));
645 tar->append(Path: "version.txt", Data: getLLDVersion() + "\n");
646 StringRef ltoSampleProfile = args.getLastArgValue(Id: OPT_lto_sample_profile);
647 if (!ltoSampleProfile.empty())
648 readFile(path: ltoSampleProfile);
649 } else {
650 error(msg: "--reproduce: " + toString(E: errOrWriter.takeError()));
651 }
652 }
653
654 readConfigs(args);
655 checkZOptions(args);
656
657 // The behavior of -v or --version is a bit strange, but this is
658 // needed for compatibility with GNU linkers.
659 if (args.hasArg(Ids: OPT_v) && !args.hasArg(Ids: OPT_INPUT))
660 return;
661 if (args.hasArg(Ids: OPT_version))
662 return;
663
664 // Initialize time trace profiler.
665 if (config->timeTraceEnabled)
666 timeTraceProfilerInitialize(TimeTraceGranularity: config->timeTraceGranularity, ProcName: config->progName);
667
668 {
669 llvm::TimeTraceScope timeScope("ExecuteLinker");
670
671 initLLVM();
672 createFiles(args);
673 if (errorCount())
674 return;
675
676 inferMachineType();
677 setConfigs(args);
678 checkOptions();
679 if (errorCount())
680 return;
681
682 invokeELFT(link, args);
683 }
684
685 if (config->timeTraceEnabled) {
686 checkError(e: timeTraceProfilerWrite(
687 PreferredFileName: args.getLastArgValue(Id: OPT_time_trace_eq).str(), FallbackFileName: config->outputFile));
688 timeTraceProfilerCleanup();
689 }
690}
691
692static std::string getRpath(opt::InputArgList &args) {
693 SmallVector<StringRef, 0> v = args::getStrings(args, id: OPT_rpath);
694 return llvm::join(Begin: v.begin(), End: v.end(), Separator: ":");
695}
696
697// Determines what we should do if there are remaining unresolved
698// symbols after the name resolution.
699static void setUnresolvedSymbolPolicy(opt::InputArgList &args) {
700 UnresolvedPolicy errorOrWarn = args.hasFlag(Pos: OPT_error_unresolved_symbols,
701 Neg: OPT_warn_unresolved_symbols, Default: true)
702 ? UnresolvedPolicy::ReportError
703 : UnresolvedPolicy::Warn;
704 // -shared implies --unresolved-symbols=ignore-all because missing
705 // symbols are likely to be resolved at runtime.
706 bool diagRegular = !config->shared, diagShlib = !config->shared;
707
708 for (const opt::Arg *arg : args) {
709 switch (arg->getOption().getID()) {
710 case OPT_unresolved_symbols: {
711 StringRef s = arg->getValue();
712 if (s == "ignore-all") {
713 diagRegular = false;
714 diagShlib = false;
715 } else if (s == "ignore-in-object-files") {
716 diagRegular = false;
717 diagShlib = true;
718 } else if (s == "ignore-in-shared-libs") {
719 diagRegular = true;
720 diagShlib = false;
721 } else if (s == "report-all") {
722 diagRegular = true;
723 diagShlib = true;
724 } else {
725 error(msg: "unknown --unresolved-symbols value: " + s);
726 }
727 break;
728 }
729 case OPT_no_undefined:
730 diagRegular = true;
731 break;
732 case OPT_z:
733 if (StringRef(arg->getValue()) == "defs")
734 diagRegular = true;
735 else if (StringRef(arg->getValue()) == "undefs")
736 diagRegular = false;
737 else
738 break;
739 arg->claim();
740 break;
741 case OPT_allow_shlib_undefined:
742 diagShlib = false;
743 break;
744 case OPT_no_allow_shlib_undefined:
745 diagShlib = true;
746 break;
747 }
748 }
749
750 config->unresolvedSymbols =
751 diagRegular ? errorOrWarn : UnresolvedPolicy::Ignore;
752 config->unresolvedSymbolsInShlib =
753 diagShlib ? errorOrWarn : UnresolvedPolicy::Ignore;
754}
755
756static Target2Policy getTarget2(opt::InputArgList &args) {
757 StringRef s = args.getLastArgValue(Id: OPT_target2, Default: "got-rel");
758 if (s == "rel")
759 return Target2Policy::Rel;
760 if (s == "abs")
761 return Target2Policy::Abs;
762 if (s == "got-rel")
763 return Target2Policy::GotRel;
764 error(msg: "unknown --target2 option: " + s);
765 return Target2Policy::GotRel;
766}
767
768static bool isOutputFormatBinary(opt::InputArgList &args) {
769 StringRef s = args.getLastArgValue(Id: OPT_oformat, Default: "elf");
770 if (s == "binary")
771 return true;
772 if (!s.starts_with(Prefix: "elf"))
773 error(msg: "unknown --oformat value: " + s);
774 return false;
775}
776
777static DiscardPolicy getDiscard(opt::InputArgList &args) {
778 auto *arg =
779 args.getLastArg(Ids: OPT_discard_all, Ids: OPT_discard_locals, Ids: OPT_discard_none);
780 if (!arg)
781 return DiscardPolicy::Default;
782 if (arg->getOption().getID() == OPT_discard_all)
783 return DiscardPolicy::All;
784 if (arg->getOption().getID() == OPT_discard_locals)
785 return DiscardPolicy::Locals;
786 return DiscardPolicy::None;
787}
788
789static StringRef getDynamicLinker(opt::InputArgList &args) {
790 auto *arg = args.getLastArg(Ids: OPT_dynamic_linker, Ids: OPT_no_dynamic_linker);
791 if (!arg)
792 return "";
793 if (arg->getOption().getID() == OPT_no_dynamic_linker) {
794 // --no-dynamic-linker suppresses undefined weak symbols in .dynsym
795 config->noDynamicLinker = true;
796 return "";
797 }
798 return arg->getValue();
799}
800
801static int getMemtagMode(opt::InputArgList &args) {
802 StringRef memtagModeArg = args.getLastArgValue(Id: OPT_android_memtag_mode);
803 if (memtagModeArg.empty()) {
804 if (config->androidMemtagStack)
805 warn(msg: "--android-memtag-mode is unspecified, leaving "
806 "--android-memtag-stack a no-op");
807 else if (config->androidMemtagHeap)
808 warn(msg: "--android-memtag-mode is unspecified, leaving "
809 "--android-memtag-heap a no-op");
810 return ELF::NT_MEMTAG_LEVEL_NONE;
811 }
812
813 if (memtagModeArg == "sync")
814 return ELF::NT_MEMTAG_LEVEL_SYNC;
815 if (memtagModeArg == "async")
816 return ELF::NT_MEMTAG_LEVEL_ASYNC;
817 if (memtagModeArg == "none")
818 return ELF::NT_MEMTAG_LEVEL_NONE;
819
820 error(msg: "unknown --android-memtag-mode value: \"" + memtagModeArg +
821 "\", should be one of {async, sync, none}");
822 return ELF::NT_MEMTAG_LEVEL_NONE;
823}
824
825static ICFLevel getICF(opt::InputArgList &args) {
826 auto *arg = args.getLastArg(Ids: OPT_icf_none, Ids: OPT_icf_safe, Ids: OPT_icf_all);
827 if (!arg || arg->getOption().getID() == OPT_icf_none)
828 return ICFLevel::None;
829 if (arg->getOption().getID() == OPT_icf_safe)
830 return ICFLevel::Safe;
831 return ICFLevel::All;
832}
833
834static StripPolicy getStrip(opt::InputArgList &args) {
835 if (args.hasArg(Ids: OPT_relocatable))
836 return StripPolicy::None;
837
838 auto *arg = args.getLastArg(Ids: OPT_strip_all, Ids: OPT_strip_debug);
839 if (!arg)
840 return StripPolicy::None;
841 if (arg->getOption().getID() == OPT_strip_all)
842 return StripPolicy::All;
843 return StripPolicy::Debug;
844}
845
846static uint64_t parseSectionAddress(StringRef s, opt::InputArgList &args,
847 const opt::Arg &arg) {
848 uint64_t va = 0;
849 if (s.starts_with(Prefix: "0x"))
850 s = s.drop_front(N: 2);
851 if (!to_integer(S: s, Num&: va, Base: 16))
852 error(msg: "invalid argument: " + arg.getAsString(Args: args));
853 return va;
854}
855
856static StringMap<uint64_t> getSectionStartMap(opt::InputArgList &args) {
857 StringMap<uint64_t> ret;
858 for (auto *arg : args.filtered(Ids: OPT_section_start)) {
859 StringRef name;
860 StringRef addr;
861 std::tie(args&: name, args&: addr) = StringRef(arg->getValue()).split(Separator: '=');
862 ret[name] = parseSectionAddress(s: addr, args, arg: *arg);
863 }
864
865 if (auto *arg = args.getLastArg(Ids: OPT_Ttext))
866 ret[".text"] = parseSectionAddress(s: arg->getValue(), args, arg: *arg);
867 if (auto *arg = args.getLastArg(Ids: OPT_Tdata))
868 ret[".data"] = parseSectionAddress(s: arg->getValue(), args, arg: *arg);
869 if (auto *arg = args.getLastArg(Ids: OPT_Tbss))
870 ret[".bss"] = parseSectionAddress(s: arg->getValue(), args, arg: *arg);
871 return ret;
872}
873
874static SortSectionPolicy getSortSection(opt::InputArgList &args) {
875 StringRef s = args.getLastArgValue(Id: OPT_sort_section);
876 if (s == "alignment")
877 return SortSectionPolicy::Alignment;
878 if (s == "name")
879 return SortSectionPolicy::Name;
880 if (!s.empty())
881 error(msg: "unknown --sort-section rule: " + s);
882 return SortSectionPolicy::Default;
883}
884
885static OrphanHandlingPolicy getOrphanHandling(opt::InputArgList &args) {
886 StringRef s = args.getLastArgValue(Id: OPT_orphan_handling, Default: "place");
887 if (s == "warn")
888 return OrphanHandlingPolicy::Warn;
889 if (s == "error")
890 return OrphanHandlingPolicy::Error;
891 if (s != "place")
892 error(msg: "unknown --orphan-handling mode: " + s);
893 return OrphanHandlingPolicy::Place;
894}
895
896// Parse --build-id or --build-id=<style>. We handle "tree" as a
897// synonym for "sha1" because all our hash functions including
898// --build-id=sha1 are actually tree hashes for performance reasons.
899static std::pair<BuildIdKind, SmallVector<uint8_t, 0>>
900getBuildId(opt::InputArgList &args) {
901 auto *arg = args.getLastArg(Ids: OPT_build_id);
902 if (!arg)
903 return {BuildIdKind::None, {}};
904
905 StringRef s = arg->getValue();
906 if (s == "fast")
907 return {BuildIdKind::Fast, {}};
908 if (s == "md5")
909 return {BuildIdKind::Md5, {}};
910 if (s == "sha1" || s == "tree")
911 return {BuildIdKind::Sha1, {}};
912 if (s == "uuid")
913 return {BuildIdKind::Uuid, {}};
914 if (s.starts_with(Prefix: "0x"))
915 return {BuildIdKind::Hexstring, parseHex(s: s.substr(Start: 2))};
916
917 if (s != "none")
918 error(msg: "unknown --build-id style: " + s);
919 return {BuildIdKind::None, {}};
920}
921
922static std::pair<bool, bool> getPackDynRelocs(opt::InputArgList &args) {
923 StringRef s = args.getLastArgValue(Id: OPT_pack_dyn_relocs, Default: "none");
924 if (s == "android")
925 return {true, false};
926 if (s == "relr")
927 return {false, true};
928 if (s == "android+relr")
929 return {true, true};
930
931 if (s != "none")
932 error(msg: "unknown --pack-dyn-relocs format: " + s);
933 return {false, false};
934}
935
936static void readCallGraph(MemoryBufferRef mb) {
937 // Build a map from symbol name to section
938 DenseMap<StringRef, Symbol *> map;
939 for (ELFFileBase *file : ctx.objectFiles)
940 for (Symbol *sym : file->getSymbols())
941 map[sym->getName()] = sym;
942
943 auto findSection = [&](StringRef name) -> InputSectionBase * {
944 Symbol *sym = map.lookup(Val: name);
945 if (!sym) {
946 if (config->warnSymbolOrdering)
947 warn(msg: mb.getBufferIdentifier() + ": no such symbol: " + name);
948 return nullptr;
949 }
950 maybeWarnUnorderableSymbol(sym);
951
952 if (Defined *dr = dyn_cast_or_null<Defined>(Val: sym))
953 return dyn_cast_or_null<InputSectionBase>(Val: dr->section);
954 return nullptr;
955 };
956
957 for (StringRef line : args::getLines(mb)) {
958 SmallVector<StringRef, 3> fields;
959 line.split(A&: fields, Separator: ' ');
960 uint64_t count;
961
962 if (fields.size() != 3 || !to_integer(S: fields[2], Num&: count)) {
963 error(msg: mb.getBufferIdentifier() + ": parse error");
964 return;
965 }
966
967 if (InputSectionBase *from = findSection(fields[0]))
968 if (InputSectionBase *to = findSection(fields[1]))
969 config->callGraphProfile[std::make_pair(x&: from, y&: to)] += count;
970 }
971}
972
973// If SHT_LLVM_CALL_GRAPH_PROFILE and its relocation section exist, returns
974// true and populates cgProfile and symbolIndices.
975template <class ELFT>
976static bool
977processCallGraphRelocations(SmallVector<uint32_t, 32> &symbolIndices,
978 ArrayRef<typename ELFT::CGProfile> &cgProfile,
979 ObjFile<ELFT> *inputObj) {
980 if (inputObj->cgProfileSectionIndex == SHN_UNDEF)
981 return false;
982
983 ArrayRef<Elf_Shdr_Impl<ELFT>> objSections =
984 inputObj->template getELFShdrs<ELFT>();
985 symbolIndices.clear();
986 const ELFFile<ELFT> &obj = inputObj->getObj();
987 cgProfile =
988 check(obj.template getSectionContentsAsArray<typename ELFT::CGProfile>(
989 objSections[inputObj->cgProfileSectionIndex]));
990
991 for (size_t i = 0, e = objSections.size(); i < e; ++i) {
992 const Elf_Shdr_Impl<ELFT> &sec = objSections[i];
993 if (sec.sh_info == inputObj->cgProfileSectionIndex) {
994 if (sec.sh_type == SHT_CREL) {
995 auto crels =
996 CHECK(obj.crels(sec), "could not retrieve cg profile rela section");
997 for (const auto &rel : crels.first)
998 symbolIndices.push_back(Elt: rel.getSymbol(false));
999 for (const auto &rel : crels.second)
1000 symbolIndices.push_back(Elt: rel.getSymbol(false));
1001 break;
1002 }
1003 if (sec.sh_type == SHT_RELA) {
1004 ArrayRef<typename ELFT::Rela> relas =
1005 CHECK(obj.relas(sec), "could not retrieve cg profile rela section");
1006 for (const typename ELFT::Rela &rel : relas)
1007 symbolIndices.push_back(Elt: rel.getSymbol(config->isMips64EL));
1008 break;
1009 }
1010 if (sec.sh_type == SHT_REL) {
1011 ArrayRef<typename ELFT::Rel> rels =
1012 CHECK(obj.rels(sec), "could not retrieve cg profile rel section");
1013 for (const typename ELFT::Rel &rel : rels)
1014 symbolIndices.push_back(Elt: rel.getSymbol(config->isMips64EL));
1015 break;
1016 }
1017 }
1018 }
1019 if (symbolIndices.empty())
1020 warn(msg: "SHT_LLVM_CALL_GRAPH_PROFILE exists, but relocation section doesn't");
1021 return !symbolIndices.empty();
1022}
1023
1024template <class ELFT> static void readCallGraphsFromObjectFiles() {
1025 SmallVector<uint32_t, 32> symbolIndices;
1026 ArrayRef<typename ELFT::CGProfile> cgProfile;
1027 for (auto file : ctx.objectFiles) {
1028 auto *obj = cast<ObjFile<ELFT>>(file);
1029 if (!processCallGraphRelocations(symbolIndices, cgProfile, obj))
1030 continue;
1031
1032 if (symbolIndices.size() != cgProfile.size() * 2)
1033 fatal(msg: "number of relocations doesn't match Weights");
1034
1035 for (uint32_t i = 0, size = cgProfile.size(); i < size; ++i) {
1036 const Elf_CGProfile_Impl<ELFT> &cgpe = cgProfile[i];
1037 uint32_t fromIndex = symbolIndices[i * 2];
1038 uint32_t toIndex = symbolIndices[i * 2 + 1];
1039 auto *fromSym = dyn_cast<Defined>(&obj->getSymbol(fromIndex));
1040 auto *toSym = dyn_cast<Defined>(&obj->getSymbol(toIndex));
1041 if (!fromSym || !toSym)
1042 continue;
1043
1044 auto *from = dyn_cast_or_null<InputSectionBase>(fromSym->section);
1045 auto *to = dyn_cast_or_null<InputSectionBase>(toSym->section);
1046 if (from && to)
1047 config->callGraphProfile[{from, to}] += cgpe.cgp_weight;
1048 }
1049 }
1050}
1051
1052template <class ELFT>
1053static void ltoValidateAllVtablesHaveTypeInfos(opt::InputArgList &args) {
1054 DenseSet<StringRef> typeInfoSymbols;
1055 SmallSetVector<StringRef, 0> vtableSymbols;
1056 auto processVtableAndTypeInfoSymbols = [&](StringRef name) {
1057 if (name.consume_front(Prefix: "_ZTI"))
1058 typeInfoSymbols.insert(V: name);
1059 else if (name.consume_front(Prefix: "_ZTV"))
1060 vtableSymbols.insert(X: name);
1061 };
1062
1063 // Examine all native symbol tables.
1064 for (ELFFileBase *f : ctx.objectFiles) {
1065 using Elf_Sym = typename ELFT::Sym;
1066 for (const Elf_Sym &s : f->template getGlobalELFSyms<ELFT>()) {
1067 if (s.st_shndx != SHN_UNDEF) {
1068 StringRef name = check(s.getName(f->getStringTable()));
1069 processVtableAndTypeInfoSymbols(name);
1070 }
1071 }
1072 }
1073
1074 for (SharedFile *f : ctx.sharedFiles) {
1075 using Elf_Sym = typename ELFT::Sym;
1076 for (const Elf_Sym &s : f->template getELFSyms<ELFT>()) {
1077 if (s.st_shndx != SHN_UNDEF) {
1078 StringRef name = check(s.getName(f->getStringTable()));
1079 processVtableAndTypeInfoSymbols(name);
1080 }
1081 }
1082 }
1083
1084 SmallSetVector<StringRef, 0> vtableSymbolsWithNoRTTI;
1085 for (StringRef s : vtableSymbols)
1086 if (!typeInfoSymbols.count(V: s))
1087 vtableSymbolsWithNoRTTI.insert(X: s);
1088
1089 // Remove known safe symbols.
1090 for (auto *arg : args.filtered(Ids: OPT_lto_known_safe_vtables)) {
1091 StringRef knownSafeName = arg->getValue();
1092 if (!knownSafeName.consume_front(Prefix: "_ZTV"))
1093 error(msg: "--lto-known-safe-vtables=: expected symbol to start with _ZTV, "
1094 "but got " +
1095 knownSafeName);
1096 Expected<GlobPattern> pat = GlobPattern::create(Pat: knownSafeName);
1097 if (!pat)
1098 error(msg: "--lto-known-safe-vtables=: " + toString(E: pat.takeError()));
1099 vtableSymbolsWithNoRTTI.remove_if(
1100 [&](StringRef s) { return pat->match(S: s); });
1101 }
1102
1103 ctx.ltoAllVtablesHaveTypeInfos = vtableSymbolsWithNoRTTI.empty();
1104 // Check for unmatched RTTI symbols
1105 for (StringRef s : vtableSymbolsWithNoRTTI) {
1106 message(
1107 msg: "--lto-validate-all-vtables-have-type-infos: RTTI missing for vtable "
1108 "_ZTV" +
1109 s + ", --lto-whole-program-visibility disabled");
1110 }
1111}
1112
1113static CGProfileSortKind getCGProfileSortKind(opt::InputArgList &args) {
1114 StringRef s = args.getLastArgValue(Id: OPT_call_graph_profile_sort, Default: "cdsort");
1115 if (s == "hfsort")
1116 return CGProfileSortKind::Hfsort;
1117 if (s == "cdsort")
1118 return CGProfileSortKind::Cdsort;
1119 if (s != "none")
1120 error(msg: "unknown --call-graph-profile-sort= value: " + s);
1121 return CGProfileSortKind::None;
1122}
1123
1124static DebugCompressionType getCompressionType(StringRef s, StringRef option) {
1125 DebugCompressionType type = StringSwitch<DebugCompressionType>(s)
1126 .Case(S: "zlib", Value: DebugCompressionType::Zlib)
1127 .Case(S: "zstd", Value: DebugCompressionType::Zstd)
1128 .Default(Value: DebugCompressionType::None);
1129 if (type == DebugCompressionType::None) {
1130 if (s != "none")
1131 error(msg: "unknown " + option + " value: " + s);
1132 } else if (const char *reason = compression::getReasonIfUnsupported(
1133 F: compression::formatFor(Type: type))) {
1134 error(msg: option + ": " + reason);
1135 }
1136 return type;
1137}
1138
1139static StringRef getAliasSpelling(opt::Arg *arg) {
1140 if (const opt::Arg *alias = arg->getAlias())
1141 return alias->getSpelling();
1142 return arg->getSpelling();
1143}
1144
1145static std::pair<StringRef, StringRef> getOldNewOptions(opt::InputArgList &args,
1146 unsigned id) {
1147 auto *arg = args.getLastArg(Ids: id);
1148 if (!arg)
1149 return {"", ""};
1150
1151 StringRef s = arg->getValue();
1152 std::pair<StringRef, StringRef> ret = s.split(Separator: ';');
1153 if (ret.second.empty())
1154 error(msg: getAliasSpelling(arg) + " expects 'old;new' format, but got " + s);
1155 return ret;
1156}
1157
1158// Parse options of the form "old;new[;extra]".
1159static std::tuple<StringRef, StringRef, StringRef>
1160getOldNewOptionsExtra(opt::InputArgList &args, unsigned id) {
1161 auto [oldDir, second] = getOldNewOptions(args, id);
1162 auto [newDir, extraDir] = second.split(Separator: ';');
1163 return {oldDir, newDir, extraDir};
1164}
1165
1166// Parse the symbol ordering file and warn for any duplicate entries.
1167static SmallVector<StringRef, 0> getSymbolOrderingFile(MemoryBufferRef mb) {
1168 SetVector<StringRef, SmallVector<StringRef, 0>> names;
1169 for (StringRef s : args::getLines(mb))
1170 if (!names.insert(X: s) && config->warnSymbolOrdering)
1171 warn(msg: mb.getBufferIdentifier() + ": duplicate ordered symbol: " + s);
1172
1173 return names.takeVector();
1174}
1175
1176static bool getIsRela(opt::InputArgList &args) {
1177 // The psABI specifies the default relocation entry format.
1178 bool rela = is_contained(Set: {EM_AARCH64, EM_AMDGPU, EM_HEXAGON, EM_LOONGARCH,
1179 EM_PPC, EM_PPC64, EM_RISCV, EM_S390, EM_X86_64},
1180 Element: config->emachine);
1181 // If -z rel or -z rela is specified, use the last option.
1182 for (auto *arg : args.filtered(Ids: OPT_z)) {
1183 StringRef s(arg->getValue());
1184 if (s == "rel")
1185 rela = false;
1186 else if (s == "rela")
1187 rela = true;
1188 else
1189 continue;
1190 arg->claim();
1191 }
1192 return rela;
1193}
1194
1195static void parseClangOption(StringRef opt, const Twine &msg) {
1196 std::string err;
1197 raw_string_ostream os(err);
1198
1199 const char *argv[] = {config->progName.data(), opt.data()};
1200 if (cl::ParseCommandLineOptions(argc: 2, argv, Overview: "", Errs: &os))
1201 return;
1202 os.flush();
1203 error(msg: msg + ": " + StringRef(err).trim());
1204}
1205
1206// Checks the parameter of the bti-report and cet-report options.
1207static bool isValidReportString(StringRef arg) {
1208 return arg == "none" || arg == "warning" || arg == "error";
1209}
1210
1211// Process a remap pattern 'from-glob=to-file'.
1212static bool remapInputs(StringRef line, const Twine &location) {
1213 SmallVector<StringRef, 0> fields;
1214 line.split(A&: fields, Separator: '=');
1215 if (fields.size() != 2 || fields[1].empty()) {
1216 error(msg: location + ": parse error, not 'from-glob=to-file'");
1217 return true;
1218 }
1219 if (!hasWildcard(s: fields[0]))
1220 config->remapInputs[fields[0]] = fields[1];
1221 else if (Expected<GlobPattern> pat = GlobPattern::create(Pat: fields[0]))
1222 config->remapInputsWildcards.emplace_back(Args: std::move(*pat), Args&: fields[1]);
1223 else {
1224 error(msg: location + ": " + toString(E: pat.takeError()) + ": " + fields[0]);
1225 return true;
1226 }
1227 return false;
1228}
1229
1230// Initializes Config members by the command line options.
1231static void readConfigs(opt::InputArgList &args) {
1232 errorHandler().verbose = args.hasArg(Ids: OPT_verbose);
1233 errorHandler().vsDiagnostics =
1234 args.hasArg(Ids: OPT_visual_studio_diagnostics_format, Ids: false);
1235
1236 config->allowMultipleDefinition =
1237 hasZOption(args, key: "muldefs") ||
1238 args.hasFlag(Pos: OPT_allow_multiple_definition,
1239 Neg: OPT_no_allow_multiple_definition, Default: false);
1240 config->androidMemtagHeap =
1241 args.hasFlag(Pos: OPT_android_memtag_heap, Neg: OPT_no_android_memtag_heap, Default: false);
1242 config->androidMemtagStack = args.hasFlag(Pos: OPT_android_memtag_stack,
1243 Neg: OPT_no_android_memtag_stack, Default: false);
1244 config->fatLTOObjects =
1245 args.hasFlag(Pos: OPT_fat_lto_objects, Neg: OPT_no_fat_lto_objects, Default: false);
1246 config->androidMemtagMode = getMemtagMode(args);
1247 config->auxiliaryList = args::getStrings(args, id: OPT_auxiliary);
1248 config->armBe8 = args.hasArg(Ids: OPT_be8);
1249 if (opt::Arg *arg = args.getLastArg(
1250 Ids: OPT_Bno_symbolic, Ids: OPT_Bsymbolic_non_weak_functions,
1251 Ids: OPT_Bsymbolic_functions, Ids: OPT_Bsymbolic_non_weak, Ids: OPT_Bsymbolic)) {
1252 if (arg->getOption().matches(ID: OPT_Bsymbolic_non_weak_functions))
1253 config->bsymbolic = BsymbolicKind::NonWeakFunctions;
1254 else if (arg->getOption().matches(ID: OPT_Bsymbolic_functions))
1255 config->bsymbolic = BsymbolicKind::Functions;
1256 else if (arg->getOption().matches(ID: OPT_Bsymbolic_non_weak))
1257 config->bsymbolic = BsymbolicKind::NonWeak;
1258 else if (arg->getOption().matches(ID: OPT_Bsymbolic))
1259 config->bsymbolic = BsymbolicKind::All;
1260 }
1261 config->callGraphProfileSort = getCGProfileSortKind(args);
1262 config->checkSections =
1263 args.hasFlag(Pos: OPT_check_sections, Neg: OPT_no_check_sections, Default: true);
1264 config->chroot = args.getLastArgValue(Id: OPT_chroot);
1265 if (auto *arg = args.getLastArg(Ids: OPT_compress_debug_sections)) {
1266 config->compressDebugSections =
1267 getCompressionType(s: arg->getValue(), option: "--compress-debug-sections");
1268 }
1269 config->cref = args.hasArg(Ids: OPT_cref);
1270 config->optimizeBBJumps =
1271 args.hasFlag(Pos: OPT_optimize_bb_jumps, Neg: OPT_no_optimize_bb_jumps, Default: false);
1272 config->debugNames = args.hasFlag(Pos: OPT_debug_names, Neg: OPT_no_debug_names, Default: false);
1273 config->demangle = args.hasFlag(Pos: OPT_demangle, Neg: OPT_no_demangle, Default: true);
1274 config->dependencyFile = args.getLastArgValue(Id: OPT_dependency_file);
1275 config->dependentLibraries = args.hasFlag(Pos: OPT_dependent_libraries, Neg: OPT_no_dependent_libraries, Default: true);
1276 config->disableVerify = args.hasArg(Ids: OPT_disable_verify);
1277 config->discard = getDiscard(args);
1278 config->dwoDir = args.getLastArgValue(Id: OPT_plugin_opt_dwo_dir_eq);
1279 config->dynamicLinker = getDynamicLinker(args);
1280 config->ehFrameHdr =
1281 args.hasFlag(Pos: OPT_eh_frame_hdr, Neg: OPT_no_eh_frame_hdr, Default: false);
1282 config->emitLLVM = args.hasArg(Ids: OPT_lto_emit_llvm);
1283 config->emitRelocs = args.hasArg(Ids: OPT_emit_relocs);
1284 config->enableNewDtags =
1285 args.hasFlag(Pos: OPT_enable_new_dtags, Neg: OPT_disable_new_dtags, Default: true);
1286 config->enableNonContiguousRegions =
1287 args.hasArg(Ids: OPT_enable_non_contiguous_regions);
1288 config->entry = args.getLastArgValue(Id: OPT_entry);
1289
1290 errorHandler().errorHandlingScript =
1291 args.getLastArgValue(Id: OPT_error_handling_script);
1292
1293 config->executeOnly =
1294 args.hasFlag(Pos: OPT_execute_only, Neg: OPT_no_execute_only, Default: false);
1295 config->exportDynamic =
1296 args.hasFlag(Pos: OPT_export_dynamic, Neg: OPT_no_export_dynamic, Default: false) ||
1297 args.hasArg(Ids: OPT_shared);
1298 config->filterList = args::getStrings(args, id: OPT_filter);
1299 config->fini = args.getLastArgValue(Id: OPT_fini, Default: "_fini");
1300 config->fixCortexA53Errata843419 = args.hasArg(Ids: OPT_fix_cortex_a53_843419) &&
1301 !args.hasArg(Ids: OPT_relocatable);
1302 config->cmseImplib = args.hasArg(Ids: OPT_cmse_implib);
1303 config->cmseInputLib = args.getLastArgValue(Id: OPT_in_implib);
1304 config->cmseOutputLib = args.getLastArgValue(Id: OPT_out_implib);
1305 config->fixCortexA8 =
1306 args.hasArg(Ids: OPT_fix_cortex_a8) && !args.hasArg(Ids: OPT_relocatable);
1307 config->fortranCommon =
1308 args.hasFlag(Pos: OPT_fortran_common, Neg: OPT_no_fortran_common, Default: false);
1309 config->gcSections = args.hasFlag(Pos: OPT_gc_sections, Neg: OPT_no_gc_sections, Default: false);
1310 config->gnuUnique = args.hasFlag(Pos: OPT_gnu_unique, Neg: OPT_no_gnu_unique, Default: true);
1311 config->gdbIndex = args.hasFlag(Pos: OPT_gdb_index, Neg: OPT_no_gdb_index, Default: false);
1312 config->icf = getICF(args);
1313 config->ignoreDataAddressEquality =
1314 args.hasArg(Ids: OPT_ignore_data_address_equality);
1315 config->ignoreFunctionAddressEquality =
1316 args.hasArg(Ids: OPT_ignore_function_address_equality);
1317 config->init = args.getLastArgValue(Id: OPT_init, Default: "_init");
1318 config->ltoAAPipeline = args.getLastArgValue(Id: OPT_lto_aa_pipeline);
1319 config->ltoCSProfileGenerate = args.hasArg(Ids: OPT_lto_cs_profile_generate);
1320 config->ltoCSProfileFile = args.getLastArgValue(Id: OPT_lto_cs_profile_file);
1321 config->ltoPGOWarnMismatch = args.hasFlag(Pos: OPT_lto_pgo_warn_mismatch,
1322 Neg: OPT_no_lto_pgo_warn_mismatch, Default: true);
1323 config->ltoDebugPassManager = args.hasArg(Ids: OPT_lto_debug_pass_manager);
1324 config->ltoEmitAsm = args.hasArg(Ids: OPT_lto_emit_asm);
1325 config->ltoNewPmPasses = args.getLastArgValue(Id: OPT_lto_newpm_passes);
1326 config->ltoWholeProgramVisibility =
1327 args.hasFlag(Pos: OPT_lto_whole_program_visibility,
1328 Neg: OPT_no_lto_whole_program_visibility, Default: false);
1329 config->ltoValidateAllVtablesHaveTypeInfos =
1330 args.hasFlag(Pos: OPT_lto_validate_all_vtables_have_type_infos,
1331 Neg: OPT_no_lto_validate_all_vtables_have_type_infos, Default: false);
1332 config->ltoo = args::getInteger(args, key: OPT_lto_O, Default: 2);
1333 if (config->ltoo > 3)
1334 error(msg: "invalid optimization level for LTO: " + Twine(config->ltoo));
1335 unsigned ltoCgo =
1336 args::getInteger(args, key: OPT_lto_CGO, Default: args::getCGOptLevel(optLevelLTO: config->ltoo));
1337 if (auto level = CodeGenOpt::getLevel(OL: ltoCgo))
1338 config->ltoCgo = *level;
1339 else
1340 error(msg: "invalid codegen optimization level for LTO: " + Twine(ltoCgo));
1341 config->ltoObjPath = args.getLastArgValue(Id: OPT_lto_obj_path_eq);
1342 config->ltoPartitions = args::getInteger(args, key: OPT_lto_partitions, Default: 1);
1343 config->ltoSampleProfile = args.getLastArgValue(Id: OPT_lto_sample_profile);
1344 config->ltoBBAddrMap =
1345 args.hasFlag(Pos: OPT_lto_basic_block_address_map,
1346 Neg: OPT_no_lto_basic_block_address_map, Default: false);
1347 config->ltoBasicBlockSections =
1348 args.getLastArgValue(Id: OPT_lto_basic_block_sections);
1349 config->ltoUniqueBasicBlockSectionNames =
1350 args.hasFlag(Pos: OPT_lto_unique_basic_block_section_names,
1351 Neg: OPT_no_lto_unique_basic_block_section_names, Default: false);
1352 config->mapFile = args.getLastArgValue(Id: OPT_Map);
1353 config->mipsGotSize = args::getInteger(args, key: OPT_mips_got_size, Default: 0xfff0);
1354 config->mergeArmExidx =
1355 args.hasFlag(Pos: OPT_merge_exidx_entries, Neg: OPT_no_merge_exidx_entries, Default: true);
1356 config->mmapOutputFile =
1357 args.hasFlag(Pos: OPT_mmap_output_file, Neg: OPT_no_mmap_output_file, Default: true);
1358 config->nmagic = args.hasFlag(Pos: OPT_nmagic, Neg: OPT_no_nmagic, Default: false);
1359 config->noinhibitExec = args.hasArg(Ids: OPT_noinhibit_exec);
1360 config->nostdlib = args.hasArg(Ids: OPT_nostdlib);
1361 config->oFormatBinary = isOutputFormatBinary(args);
1362 config->omagic = args.hasFlag(Pos: OPT_omagic, Neg: OPT_no_omagic, Default: false);
1363 config->optRemarksFilename = args.getLastArgValue(Id: OPT_opt_remarks_filename);
1364 config->optStatsFilename = args.getLastArgValue(Id: OPT_plugin_opt_stats_file);
1365
1366 // Parse remarks hotness threshold. Valid value is either integer or 'auto'.
1367 if (auto *arg = args.getLastArg(Ids: OPT_opt_remarks_hotness_threshold)) {
1368 auto resultOrErr = remarks::parseHotnessThresholdOption(Arg: arg->getValue());
1369 if (!resultOrErr)
1370 error(msg: arg->getSpelling() + ": invalid argument '" + arg->getValue() +
1371 "', only integer or 'auto' is supported");
1372 else
1373 config->optRemarksHotnessThreshold = *resultOrErr;
1374 }
1375
1376 config->optRemarksPasses = args.getLastArgValue(Id: OPT_opt_remarks_passes);
1377 config->optRemarksWithHotness = args.hasArg(Ids: OPT_opt_remarks_with_hotness);
1378 config->optRemarksFormat = args.getLastArgValue(Id: OPT_opt_remarks_format);
1379 config->optimize = args::getInteger(args, key: OPT_O, Default: 1);
1380 config->orphanHandling = getOrphanHandling(args);
1381 config->outputFile = args.getLastArgValue(Id: OPT_o);
1382 config->packageMetadata = args.getLastArgValue(Id: OPT_package_metadata);
1383 config->pie = args.hasFlag(Pos: OPT_pie, Neg: OPT_no_pie, Default: false);
1384 config->printIcfSections =
1385 args.hasFlag(Pos: OPT_print_icf_sections, Neg: OPT_no_print_icf_sections, Default: false);
1386 config->printGcSections =
1387 args.hasFlag(Pos: OPT_print_gc_sections, Neg: OPT_no_print_gc_sections, Default: false);
1388 config->printMemoryUsage = args.hasArg(Ids: OPT_print_memory_usage);
1389 config->printArchiveStats = args.getLastArgValue(Id: OPT_print_archive_stats);
1390 config->printSymbolOrder =
1391 args.getLastArgValue(Id: OPT_print_symbol_order);
1392 config->rejectMismatch = !args.hasArg(Ids: OPT_no_warn_mismatch);
1393 config->relax = args.hasFlag(Pos: OPT_relax, Neg: OPT_no_relax, Default: true);
1394 config->relaxGP = args.hasFlag(Pos: OPT_relax_gp, Neg: OPT_no_relax_gp, Default: false);
1395 config->rpath = getRpath(args);
1396 config->relocatable = args.hasArg(Ids: OPT_relocatable);
1397 config->resolveGroups =
1398 !args.hasArg(Ids: OPT_relocatable) || args.hasArg(Ids: OPT_force_group_allocation);
1399
1400 if (args.hasArg(Ids: OPT_save_temps)) {
1401 // --save-temps implies saving all temps.
1402 for (const char *s : saveTempsValues)
1403 config->saveTempsArgs.insert(V: s);
1404 } else {
1405 for (auto *arg : args.filtered(Ids: OPT_save_temps_eq)) {
1406 StringRef s = arg->getValue();
1407 if (llvm::is_contained(Range: saveTempsValues, Element: s))
1408 config->saveTempsArgs.insert(V: s);
1409 else
1410 error(msg: "unknown --save-temps value: " + s);
1411 }
1412 }
1413
1414 config->searchPaths = args::getStrings(args, id: OPT_library_path);
1415 config->sectionStartMap = getSectionStartMap(args);
1416 config->shared = args.hasArg(Ids: OPT_shared);
1417 config->singleRoRx = !args.hasFlag(Pos: OPT_rosegment, Neg: OPT_no_rosegment, Default: true);
1418 config->soName = args.getLastArgValue(Id: OPT_soname);
1419 config->sortSection = getSortSection(args);
1420 config->splitStackAdjustSize = args::getInteger(args, key: OPT_split_stack_adjust_size, Default: 16384);
1421 config->strip = getStrip(args);
1422 config->sysroot = args.getLastArgValue(Id: OPT_sysroot);
1423 config->target1Rel = args.hasFlag(Pos: OPT_target1_rel, Neg: OPT_target1_abs, Default: false);
1424 config->target2 = getTarget2(args);
1425 config->thinLTOCacheDir = args.getLastArgValue(Id: OPT_thinlto_cache_dir);
1426 config->thinLTOCachePolicy = CHECK(
1427 parseCachePruningPolicy(args.getLastArgValue(OPT_thinlto_cache_policy)),
1428 "--thinlto-cache-policy: invalid cache policy");
1429 config->thinLTOEmitImportsFiles = args.hasArg(Ids: OPT_thinlto_emit_imports_files);
1430 config->thinLTOEmitIndexFiles = args.hasArg(Ids: OPT_thinlto_emit_index_files) ||
1431 args.hasArg(Ids: OPT_thinlto_index_only) ||
1432 args.hasArg(Ids: OPT_thinlto_index_only_eq);
1433 config->thinLTOIndexOnly = args.hasArg(Ids: OPT_thinlto_index_only) ||
1434 args.hasArg(Ids: OPT_thinlto_index_only_eq);
1435 config->thinLTOIndexOnlyArg = args.getLastArgValue(Id: OPT_thinlto_index_only_eq);
1436 config->thinLTOObjectSuffixReplace =
1437 getOldNewOptions(args, id: OPT_thinlto_object_suffix_replace_eq);
1438 std::tie(args&: config->thinLTOPrefixReplaceOld, args&: config->thinLTOPrefixReplaceNew,
1439 args&: config->thinLTOPrefixReplaceNativeObject) =
1440 getOldNewOptionsExtra(args, id: OPT_thinlto_prefix_replace_eq);
1441 if (config->thinLTOEmitIndexFiles && !config->thinLTOIndexOnly) {
1442 if (args.hasArg(Ids: OPT_thinlto_object_suffix_replace_eq))
1443 error(msg: "--thinlto-object-suffix-replace is not supported with "
1444 "--thinlto-emit-index-files");
1445 else if (args.hasArg(Ids: OPT_thinlto_prefix_replace_eq))
1446 error(msg: "--thinlto-prefix-replace is not supported with "
1447 "--thinlto-emit-index-files");
1448 }
1449 if (!config->thinLTOPrefixReplaceNativeObject.empty() &&
1450 config->thinLTOIndexOnlyArg.empty()) {
1451 error(msg: "--thinlto-prefix-replace=old_dir;new_dir;obj_dir must be used with "
1452 "--thinlto-index-only=");
1453 }
1454 config->thinLTOModulesToCompile =
1455 args::getStrings(args, id: OPT_thinlto_single_module_eq);
1456 config->timeTraceEnabled = args.hasArg(Ids: OPT_time_trace_eq);
1457 config->timeTraceGranularity =
1458 args::getInteger(args, key: OPT_time_trace_granularity, Default: 500);
1459 config->trace = args.hasArg(Ids: OPT_trace);
1460 config->undefined = args::getStrings(args, id: OPT_undefined);
1461 config->undefinedVersion =
1462 args.hasFlag(Pos: OPT_undefined_version, Neg: OPT_no_undefined_version, Default: false);
1463 config->unique = args.hasArg(Ids: OPT_unique);
1464 config->useAndroidRelrTags = args.hasFlag(
1465 Pos: OPT_use_android_relr_tags, Neg: OPT_no_use_android_relr_tags, Default: false);
1466 config->warnBackrefs =
1467 args.hasFlag(Pos: OPT_warn_backrefs, Neg: OPT_no_warn_backrefs, Default: false);
1468 config->warnCommon = args.hasFlag(Pos: OPT_warn_common, Neg: OPT_no_warn_common, Default: false);
1469 config->warnSymbolOrdering =
1470 args.hasFlag(Pos: OPT_warn_symbol_ordering, Neg: OPT_no_warn_symbol_ordering, Default: true);
1471 config->whyExtract = args.getLastArgValue(Id: OPT_why_extract);
1472 config->zCombreloc = getZFlag(args, k1: "combreloc", k2: "nocombreloc", defaultValue: true);
1473 config->zCopyreloc = getZFlag(args, k1: "copyreloc", k2: "nocopyreloc", defaultValue: true);
1474 config->zForceBti = hasZOption(args, key: "force-bti");
1475 config->zForceIbt = hasZOption(args, key: "force-ibt");
1476 config->zGcs = getZGcs(args);
1477 config->zGlobal = hasZOption(args, key: "global");
1478 config->zGnustack = getZGnuStack(args);
1479 config->zHazardplt = hasZOption(args, key: "hazardplt");
1480 config->zIfuncNoplt = hasZOption(args, key: "ifunc-noplt");
1481 config->zInitfirst = hasZOption(args, key: "initfirst");
1482 config->zInterpose = hasZOption(args, key: "interpose");
1483 config->zKeepTextSectionPrefix = getZFlag(
1484 args, k1: "keep-text-section-prefix", k2: "nokeep-text-section-prefix", defaultValue: false);
1485 config->zLrodataAfterBss =
1486 getZFlag(args, k1: "lrodata-after-bss", k2: "nolrodata-after-bss", defaultValue: false);
1487 config->zNodefaultlib = hasZOption(args, key: "nodefaultlib");
1488 config->zNodelete = hasZOption(args, key: "nodelete");
1489 config->zNodlopen = hasZOption(args, key: "nodlopen");
1490 config->zNow = getZFlag(args, k1: "now", k2: "lazy", defaultValue: false);
1491 config->zOrigin = hasZOption(args, key: "origin");
1492 config->zPacPlt = hasZOption(args, key: "pac-plt");
1493 config->zRelro = getZFlag(args, k1: "relro", k2: "norelro", defaultValue: true);
1494 config->zRetpolineplt = hasZOption(args, key: "retpolineplt");
1495 config->zRodynamic = hasZOption(args, key: "rodynamic");
1496 config->zSeparate = getZSeparate(args);
1497 config->zShstk = hasZOption(args, key: "shstk");
1498 config->zStackSize = args::getZOptionValue(args, id: OPT_z, key: "stack-size", Default: 0);
1499 config->zStartStopGC =
1500 getZFlag(args, k1: "start-stop-gc", k2: "nostart-stop-gc", defaultValue: true);
1501 config->zStartStopVisibility = getZStartStopVisibility(args);
1502 config->zText = getZFlag(args, k1: "text", k2: "notext", defaultValue: true);
1503 config->zWxneeded = hasZOption(args, key: "wxneeded");
1504 setUnresolvedSymbolPolicy(args);
1505 config->power10Stubs = args.getLastArgValue(Id: OPT_power10_stubs_eq) != "no";
1506
1507 if (opt::Arg *arg = args.getLastArg(Ids: OPT_eb, Ids: OPT_el)) {
1508 if (arg->getOption().matches(ID: OPT_eb))
1509 config->optEB = true;
1510 else
1511 config->optEL = true;
1512 }
1513
1514 for (opt::Arg *arg : args.filtered(Ids: OPT_remap_inputs)) {
1515 StringRef value(arg->getValue());
1516 remapInputs(line: value, location: arg->getSpelling());
1517 }
1518 for (opt::Arg *arg : args.filtered(Ids: OPT_remap_inputs_file)) {
1519 StringRef filename(arg->getValue());
1520 std::optional<MemoryBufferRef> buffer = readFile(path: filename);
1521 if (!buffer)
1522 continue;
1523 // Parse 'from-glob=to-file' lines, ignoring #-led comments.
1524 for (auto [lineno, line] : llvm::enumerate(First: args::getLines(mb: *buffer)))
1525 if (remapInputs(line, location: filename + ":" + Twine(lineno + 1)))
1526 break;
1527 }
1528
1529 for (opt::Arg *arg : args.filtered(Ids: OPT_shuffle_sections)) {
1530 constexpr StringRef errPrefix = "--shuffle-sections=: ";
1531 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
1532 if (kv.first.empty() || kv.second.empty()) {
1533 error(msg: errPrefix + "expected <section_glob>=<seed>, but got '" +
1534 arg->getValue() + "'");
1535 continue;
1536 }
1537 // Signed so that <section_glob>=-1 is allowed.
1538 int64_t v;
1539 if (!to_integer(S: kv.second, Num&: v))
1540 error(msg: errPrefix + "expected an integer, but got '" + kv.second + "'");
1541 else if (Expected<GlobPattern> pat = GlobPattern::create(Pat: kv.first))
1542 config->shuffleSections.emplace_back(Args: std::move(*pat), Args: uint32_t(v));
1543 else
1544 error(msg: errPrefix + toString(E: pat.takeError()) + ": " + kv.first);
1545 }
1546
1547 auto reports = {std::make_pair(x: "bti-report", y: &config->zBtiReport),
1548 std::make_pair(x: "cet-report", y: &config->zCetReport),
1549 std::make_pair(x: "gcs-report", y: &config->zGcsReport),
1550 std::make_pair(x: "pauth-report", y: &config->zPauthReport)};
1551 for (opt::Arg *arg : args.filtered(Ids: OPT_z)) {
1552 std::pair<StringRef, StringRef> option =
1553 StringRef(arg->getValue()).split(Separator: '=');
1554 for (auto reportArg : reports) {
1555 if (option.first != reportArg.first)
1556 continue;
1557 arg->claim();
1558 if (!isValidReportString(arg: option.second)) {
1559 error(msg: Twine("-z ") + reportArg.first + "= parameter " + option.second +
1560 " is not recognized");
1561 continue;
1562 }
1563 *reportArg.second = option.second;
1564 }
1565 }
1566
1567 for (opt::Arg *arg : args.filtered(Ids: OPT_compress_sections)) {
1568 SmallVector<StringRef, 0> fields;
1569 StringRef(arg->getValue()).split(A&: fields, Separator: '=');
1570 if (fields.size() != 2 || fields[1].empty()) {
1571 error(msg: arg->getSpelling() +
1572 ": parse error, not 'section-glob=[none|zlib|zstd]'");
1573 continue;
1574 }
1575 auto [typeStr, levelStr] = fields[1].split(Separator: ':');
1576 auto type = getCompressionType(s: typeStr, option: arg->getSpelling());
1577 unsigned level = 0;
1578 if (fields[1].size() != typeStr.size() &&
1579 !llvm::to_integer(S: levelStr, Num&: level)) {
1580 error(msg: arg->getSpelling() +
1581 ": expected a non-negative integer compression level, but got '" +
1582 levelStr + "'");
1583 }
1584 if (Expected<GlobPattern> pat = GlobPattern::create(Pat: fields[0])) {
1585 config->compressSections.emplace_back(Args: std::move(*pat), Args&: type, Args&: level);
1586 } else {
1587 error(msg: arg->getSpelling() + ": " + toString(E: pat.takeError()));
1588 continue;
1589 }
1590 }
1591
1592 for (opt::Arg *arg : args.filtered(Ids: OPT_z)) {
1593 std::pair<StringRef, StringRef> option =
1594 StringRef(arg->getValue()).split(Separator: '=');
1595 if (option.first != "dead-reloc-in-nonalloc")
1596 continue;
1597 arg->claim();
1598 constexpr StringRef errPrefix = "-z dead-reloc-in-nonalloc=: ";
1599 std::pair<StringRef, StringRef> kv = option.second.split(Separator: '=');
1600 if (kv.first.empty() || kv.second.empty()) {
1601 error(msg: errPrefix + "expected <section_glob>=<value>");
1602 continue;
1603 }
1604 uint64_t v;
1605 if (!to_integer(S: kv.second, Num&: v))
1606 error(msg: errPrefix + "expected a non-negative integer, but got '" +
1607 kv.second + "'");
1608 else if (Expected<GlobPattern> pat = GlobPattern::create(Pat: kv.first))
1609 config->deadRelocInNonAlloc.emplace_back(Args: std::move(*pat), Args&: v);
1610 else
1611 error(msg: errPrefix + toString(E: pat.takeError()) + ": " + kv.first);
1612 }
1613
1614 cl::ResetAllOptionOccurrences();
1615
1616 // Parse LTO options.
1617 if (auto *arg = args.getLastArg(Ids: OPT_plugin_opt_mcpu_eq))
1618 parseClangOption(opt: saver().save(S: "-mcpu=" + StringRef(arg->getValue())),
1619 msg: arg->getSpelling());
1620
1621 for (opt::Arg *arg : args.filtered(Ids: OPT_plugin_opt_eq_minus))
1622 parseClangOption(opt: std::string("-") + arg->getValue(), msg: arg->getSpelling());
1623
1624 // GCC collect2 passes -plugin-opt=path/to/lto-wrapper with an absolute or
1625 // relative path. Just ignore. If not ended with "lto-wrapper" (or
1626 // "lto-wrapper.exe" for GCC cross-compiled for Windows), consider it an
1627 // unsupported LLVMgold.so option and error.
1628 for (opt::Arg *arg : args.filtered(Ids: OPT_plugin_opt_eq)) {
1629 StringRef v(arg->getValue());
1630 if (!v.ends_with(Suffix: "lto-wrapper") && !v.ends_with(Suffix: "lto-wrapper.exe"))
1631 error(msg: arg->getSpelling() + ": unknown plugin option '" + arg->getValue() +
1632 "'");
1633 }
1634
1635 config->passPlugins = args::getStrings(args, id: OPT_load_pass_plugins);
1636
1637 // Parse -mllvm options.
1638 for (const auto *arg : args.filtered(Ids: OPT_mllvm)) {
1639 parseClangOption(opt: arg->getValue(), msg: arg->getSpelling());
1640 config->mllvmOpts.emplace_back(Args: arg->getValue());
1641 }
1642
1643 config->ltoKind = LtoKind::Default;
1644 if (auto *arg = args.getLastArg(Ids: OPT_lto)) {
1645 StringRef s = arg->getValue();
1646 if (s == "thin")
1647 config->ltoKind = LtoKind::UnifiedThin;
1648 else if (s == "full")
1649 config->ltoKind = LtoKind::UnifiedRegular;
1650 else if (s == "default")
1651 config->ltoKind = LtoKind::Default;
1652 else
1653 error(msg: "unknown LTO mode: " + s);
1654 }
1655
1656 // --threads= takes a positive integer and provides the default value for
1657 // --thinlto-jobs=. If unspecified, cap the number of threads since
1658 // overhead outweighs optimization for used parallel algorithms for the
1659 // non-LTO parts.
1660 if (auto *arg = args.getLastArg(Ids: OPT_threads)) {
1661 StringRef v(arg->getValue());
1662 unsigned threads = 0;
1663 if (!llvm::to_integer(S: v, Num&: threads, Base: 0) || threads == 0)
1664 error(msg: arg->getSpelling() + ": expected a positive integer, but got '" +
1665 arg->getValue() + "'");
1666 parallel::strategy = hardware_concurrency(ThreadCount: threads);
1667 config->thinLTOJobs = v;
1668 } else if (parallel::strategy.compute_thread_count() > 16) {
1669 log(msg: "set maximum concurrency to 16, specify --threads= to change");
1670 parallel::strategy = hardware_concurrency(ThreadCount: 16);
1671 }
1672 if (auto *arg = args.getLastArg(Ids: OPT_thinlto_jobs_eq))
1673 config->thinLTOJobs = arg->getValue();
1674 config->threadCount = parallel::strategy.compute_thread_count();
1675
1676 if (config->ltoPartitions == 0)
1677 error(msg: "--lto-partitions: number of threads must be > 0");
1678 if (!get_threadpool_strategy(Num: config->thinLTOJobs))
1679 error(msg: "--thinlto-jobs: invalid job count: " + config->thinLTOJobs);
1680
1681 if (config->splitStackAdjustSize < 0)
1682 error(msg: "--split-stack-adjust-size: size must be >= 0");
1683
1684 // The text segment is traditionally the first segment, whose address equals
1685 // the base address. However, lld places the R PT_LOAD first. -Ttext-segment
1686 // is an old-fashioned option that does not play well with lld's layout.
1687 // Suggest --image-base as a likely alternative.
1688 if (args.hasArg(Ids: OPT_Ttext_segment))
1689 error(msg: "-Ttext-segment is not supported. Use --image-base if you "
1690 "intend to set the base address");
1691
1692 // Parse ELF{32,64}{LE,BE} and CPU type.
1693 if (auto *arg = args.getLastArg(Ids: OPT_m)) {
1694 StringRef s = arg->getValue();
1695 std::tie(args&: config->ekind, args&: config->emachine, args&: config->osabi) =
1696 parseEmulation(emul: s);
1697 config->mipsN32Abi =
1698 (s.starts_with(Prefix: "elf32btsmipn32") || s.starts_with(Prefix: "elf32ltsmipn32"));
1699 config->emulation = s;
1700 }
1701
1702 // Parse --hash-style={sysv,gnu,both}.
1703 if (auto *arg = args.getLastArg(Ids: OPT_hash_style)) {
1704 StringRef s = arg->getValue();
1705 if (s == "sysv")
1706 config->sysvHash = true;
1707 else if (s == "gnu")
1708 config->gnuHash = true;
1709 else if (s == "both")
1710 config->sysvHash = config->gnuHash = true;
1711 else
1712 error(msg: "unknown --hash-style: " + s);
1713 }
1714
1715 if (args.hasArg(Ids: OPT_print_map))
1716 config->mapFile = "-";
1717
1718 // Page alignment can be disabled by the -n (--nmagic) and -N (--omagic).
1719 // As PT_GNU_RELRO relies on Paging, do not create it when we have disabled
1720 // it. Also disable RELRO for -r.
1721 if (config->nmagic || config->omagic || config->relocatable)
1722 config->zRelro = false;
1723
1724 std::tie(args&: config->buildId, args&: config->buildIdVector) = getBuildId(args);
1725
1726 if (getZFlag(args, k1: "pack-relative-relocs", k2: "nopack-relative-relocs", defaultValue: false)) {
1727 config->relrGlibc = true;
1728 config->relrPackDynRelocs = true;
1729 } else {
1730 std::tie(args&: config->androidPackDynRelocs, args&: config->relrPackDynRelocs) =
1731 getPackDynRelocs(args);
1732 }
1733
1734 if (auto *arg = args.getLastArg(Ids: OPT_symbol_ordering_file)){
1735 if (args.hasArg(Ids: OPT_call_graph_ordering_file))
1736 error(msg: "--symbol-ordering-file and --call-graph-order-file "
1737 "may not be used together");
1738 if (std::optional<MemoryBufferRef> buffer = readFile(path: arg->getValue())) {
1739 config->symbolOrderingFile = getSymbolOrderingFile(mb: *buffer);
1740 // Also need to disable CallGraphProfileSort to prevent
1741 // LLD order symbols with CGProfile
1742 config->callGraphProfileSort = CGProfileSortKind::None;
1743 }
1744 }
1745
1746 assert(config->versionDefinitions.empty());
1747 config->versionDefinitions.push_back(
1748 Elt: {.name: "local", .id: (uint16_t)VER_NDX_LOCAL, .nonLocalPatterns: {}, .localPatterns: {}});
1749 config->versionDefinitions.push_back(
1750 Elt: {.name: "global", .id: (uint16_t)VER_NDX_GLOBAL, .nonLocalPatterns: {}, .localPatterns: {}});
1751
1752 // If --retain-symbol-file is used, we'll keep only the symbols listed in
1753 // the file and discard all others.
1754 if (auto *arg = args.getLastArg(Ids: OPT_retain_symbols_file)) {
1755 config->versionDefinitions[VER_NDX_LOCAL].nonLocalPatterns.push_back(
1756 Elt: {.name: "*", /*isExternCpp=*/false, /*hasWildcard=*/true});
1757 if (std::optional<MemoryBufferRef> buffer = readFile(path: arg->getValue()))
1758 for (StringRef s : args::getLines(mb: *buffer))
1759 config->versionDefinitions[VER_NDX_GLOBAL].nonLocalPatterns.push_back(
1760 Elt: {.name: s, /*isExternCpp=*/false, /*hasWildcard=*/false});
1761 }
1762
1763 for (opt::Arg *arg : args.filtered(Ids: OPT_warn_backrefs_exclude)) {
1764 StringRef pattern(arg->getValue());
1765 if (Expected<GlobPattern> pat = GlobPattern::create(Pat: pattern))
1766 config->warnBackrefsExclude.push_back(Elt: std::move(*pat));
1767 else
1768 error(msg: arg->getSpelling() + ": " + toString(E: pat.takeError()) + ": " +
1769 pattern);
1770 }
1771
1772 // For -no-pie and -pie, --export-dynamic-symbol specifies defined symbols
1773 // which should be exported. For -shared, references to matched non-local
1774 // STV_DEFAULT symbols are not bound to definitions within the shared object,
1775 // even if other options express a symbolic intention: -Bsymbolic,
1776 // -Bsymbolic-functions (if STT_FUNC), --dynamic-list.
1777 for (auto *arg : args.filtered(Ids: OPT_export_dynamic_symbol))
1778 config->dynamicList.push_back(
1779 Elt: {.name: arg->getValue(), /*isExternCpp=*/false,
1780 /*hasWildcard=*/hasWildcard(s: arg->getValue())});
1781
1782 // --export-dynamic-symbol-list specifies a list of --export-dynamic-symbol
1783 // patterns. --dynamic-list is --export-dynamic-symbol-list plus -Bsymbolic
1784 // like semantics.
1785 config->symbolic =
1786 config->bsymbolic == BsymbolicKind::All || args.hasArg(Ids: OPT_dynamic_list);
1787 for (auto *arg :
1788 args.filtered(Ids: OPT_dynamic_list, Ids: OPT_export_dynamic_symbol_list))
1789 if (std::optional<MemoryBufferRef> buffer = readFile(path: arg->getValue()))
1790 readDynamicList(mb: *buffer);
1791
1792 for (auto *arg : args.filtered(Ids: OPT_version_script))
1793 if (std::optional<std::string> path = searchScript(path: arg->getValue())) {
1794 if (std::optional<MemoryBufferRef> buffer = readFile(path: *path))
1795 readVersionScript(mb: *buffer);
1796 } else {
1797 error(msg: Twine("cannot find version script ") + arg->getValue());
1798 }
1799}
1800
1801// Some Config members do not directly correspond to any particular
1802// command line options, but computed based on other Config values.
1803// This function initialize such members. See Config.h for the details
1804// of these values.
1805static void setConfigs(opt::InputArgList &args) {
1806 ELFKind k = config->ekind;
1807 uint16_t m = config->emachine;
1808
1809 config->copyRelocs = (config->relocatable || config->emitRelocs);
1810 config->is64 = (k == ELF64LEKind || k == ELF64BEKind);
1811 config->isLE = (k == ELF32LEKind || k == ELF64LEKind);
1812 config->endianness = config->isLE ? endianness::little : endianness::big;
1813 config->isMips64EL = (k == ELF64LEKind && m == EM_MIPS);
1814 config->isPic = config->pie || config->shared;
1815 config->picThunk = args.hasArg(Ids: OPT_pic_veneer, Ids: config->isPic);
1816 config->wordsize = config->is64 ? 8 : 4;
1817
1818 // ELF defines two different ways to store relocation addends as shown below:
1819 //
1820 // Rel: Addends are stored to the location where relocations are applied. It
1821 // cannot pack the full range of addend values for all relocation types, but
1822 // this only affects relocation types that we don't support emitting as
1823 // dynamic relocations (see getDynRel).
1824 // Rela: Addends are stored as part of relocation entry.
1825 //
1826 // In other words, Rela makes it easy to read addends at the price of extra
1827 // 4 or 8 byte for each relocation entry.
1828 //
1829 // We pick the format for dynamic relocations according to the psABI for each
1830 // processor, but a contrary choice can be made if the dynamic loader
1831 // supports.
1832 config->isRela = getIsRela(args);
1833
1834 // If the output uses REL relocations we must store the dynamic relocation
1835 // addends to the output sections. We also store addends for RELA relocations
1836 // if --apply-dynamic-relocs is used.
1837 // We default to not writing the addends when using RELA relocations since
1838 // any standard conforming tool can find it in r_addend.
1839 config->writeAddends = args.hasFlag(Pos: OPT_apply_dynamic_relocs,
1840 Neg: OPT_no_apply_dynamic_relocs, Default: false) ||
1841 !config->isRela;
1842 // Validation of dynamic relocation addends is on by default for assertions
1843 // builds and disabled otherwise. This check is enabled when writeAddends is
1844 // true.
1845#ifndef NDEBUG
1846 bool checkDynamicRelocsDefault = true;
1847#else
1848 bool checkDynamicRelocsDefault = false;
1849#endif
1850 config->checkDynamicRelocs =
1851 args.hasFlag(Pos: OPT_check_dynamic_relocations,
1852 Neg: OPT_no_check_dynamic_relocations, Default: checkDynamicRelocsDefault);
1853 config->tocOptimize =
1854 args.hasFlag(Pos: OPT_toc_optimize, Neg: OPT_no_toc_optimize, Default: m == EM_PPC64);
1855 config->pcRelOptimize =
1856 args.hasFlag(Pos: OPT_pcrel_optimize, Neg: OPT_no_pcrel_optimize, Default: m == EM_PPC64);
1857
1858 if (!args.hasArg(Ids: OPT_hash_style)) {
1859 if (config->emachine == EM_MIPS)
1860 config->sysvHash = true;
1861 else
1862 config->sysvHash = config->gnuHash = true;
1863 }
1864
1865 // Set default entry point and output file if not specified by command line or
1866 // linker scripts.
1867 config->warnMissingEntry =
1868 (!config->entry.empty() || (!config->shared && !config->relocatable));
1869 if (config->entry.empty() && !config->relocatable)
1870 config->entry = config->emachine == EM_MIPS ? "__start" : "_start";
1871 if (config->outputFile.empty())
1872 config->outputFile = "a.out";
1873
1874 // Fail early if the output file or map file is not writable. If a user has a
1875 // long link, e.g. due to a large LTO link, they do not wish to run it and
1876 // find that it failed because there was a mistake in their command-line.
1877 {
1878 llvm::TimeTraceScope timeScope("Create output files");
1879 if (auto e = tryCreateFile(path: config->outputFile))
1880 error(msg: "cannot open output file " + config->outputFile + ": " +
1881 e.message());
1882 if (auto e = tryCreateFile(path: config->mapFile))
1883 error(msg: "cannot open map file " + config->mapFile + ": " + e.message());
1884 if (auto e = tryCreateFile(path: config->whyExtract))
1885 error(msg: "cannot open --why-extract= file " + config->whyExtract + ": " +
1886 e.message());
1887 }
1888}
1889
1890static bool isFormatBinary(StringRef s) {
1891 if (s == "binary")
1892 return true;
1893 if (s == "elf" || s == "default")
1894 return false;
1895 error(msg: "unknown --format value: " + s +
1896 " (supported formats: elf, default, binary)");
1897 return false;
1898}
1899
1900void LinkerDriver::createFiles(opt::InputArgList &args) {
1901 llvm::TimeTraceScope timeScope("Load input files");
1902 // For --{push,pop}-state.
1903 std::vector<std::tuple<bool, bool, bool>> stack;
1904
1905 // -r implies -Bstatic and has precedence over -Bdynamic.
1906 config->isStatic = config->relocatable;
1907
1908 // Iterate over argv to process input files and positional arguments.
1909 std::optional<MemoryBufferRef> defaultScript;
1910 InputFile::isInGroup = false;
1911 bool hasInput = false, hasScript = false;
1912 for (auto *arg : args) {
1913 switch (arg->getOption().getID()) {
1914 case OPT_library:
1915 addLibrary(name: arg->getValue());
1916 hasInput = true;
1917 break;
1918 case OPT_INPUT:
1919 addFile(path: arg->getValue(), /*withLOption=*/false);
1920 hasInput = true;
1921 break;
1922 case OPT_defsym: {
1923 StringRef from;
1924 StringRef to;
1925 std::tie(args&: from, args&: to) = StringRef(arg->getValue()).split(Separator: '=');
1926 if (from.empty() || to.empty())
1927 error(msg: "--defsym: syntax error: " + StringRef(arg->getValue()));
1928 else
1929 readDefsym(name: from, mb: MemoryBufferRef(to, "--defsym"));
1930 break;
1931 }
1932 case OPT_script:
1933 case OPT_default_script:
1934 if (std::optional<std::string> path = searchScript(path: arg->getValue())) {
1935 if (std::optional<MemoryBufferRef> mb = readFile(path: *path)) {
1936 if (arg->getOption().matches(ID: OPT_default_script)) {
1937 defaultScript = mb;
1938 } else {
1939 readLinkerScript(mb: *mb);
1940 hasScript = true;
1941 }
1942 }
1943 break;
1944 }
1945 error(msg: Twine("cannot find linker script ") + arg->getValue());
1946 break;
1947 case OPT_as_needed:
1948 config->asNeeded = true;
1949 break;
1950 case OPT_format:
1951 config->formatBinary = isFormatBinary(s: arg->getValue());
1952 break;
1953 case OPT_no_as_needed:
1954 config->asNeeded = false;
1955 break;
1956 case OPT_Bstatic:
1957 case OPT_omagic:
1958 case OPT_nmagic:
1959 config->isStatic = true;
1960 break;
1961 case OPT_Bdynamic:
1962 if (!config->relocatable)
1963 config->isStatic = false;
1964 break;
1965 case OPT_whole_archive:
1966 inWholeArchive = true;
1967 break;
1968 case OPT_no_whole_archive:
1969 inWholeArchive = false;
1970 break;
1971 case OPT_just_symbols:
1972 if (std::optional<MemoryBufferRef> mb = readFile(path: arg->getValue())) {
1973 files.push_back(x: createObjFile(mb: *mb));
1974 files.back()->justSymbols = true;
1975 }
1976 break;
1977 case OPT_in_implib:
1978 if (armCmseImpLib)
1979 error(msg: "multiple CMSE import libraries not supported");
1980 else if (std::optional<MemoryBufferRef> mb = readFile(path: arg->getValue()))
1981 armCmseImpLib = createObjFile(mb: *mb);
1982 break;
1983 case OPT_start_group:
1984 if (InputFile::isInGroup)
1985 error(msg: "nested --start-group");
1986 InputFile::isInGroup = true;
1987 break;
1988 case OPT_end_group:
1989 if (!InputFile::isInGroup)
1990 error(msg: "stray --end-group");
1991 InputFile::isInGroup = false;
1992 ++InputFile::nextGroupId;
1993 break;
1994 case OPT_start_lib:
1995 if (inLib)
1996 error(msg: "nested --start-lib");
1997 if (InputFile::isInGroup)
1998 error(msg: "may not nest --start-lib in --start-group");
1999 inLib = true;
2000 InputFile::isInGroup = true;
2001 break;
2002 case OPT_end_lib:
2003 if (!inLib)
2004 error(msg: "stray --end-lib");
2005 inLib = false;
2006 InputFile::isInGroup = false;
2007 ++InputFile::nextGroupId;
2008 break;
2009 case OPT_push_state:
2010 stack.emplace_back(args&: config->asNeeded, args&: config->isStatic, args&: inWholeArchive);
2011 break;
2012 case OPT_pop_state:
2013 if (stack.empty()) {
2014 error(msg: "unbalanced --push-state/--pop-state");
2015 break;
2016 }
2017 std::tie(args&: config->asNeeded, args&: config->isStatic, args&: inWholeArchive) = stack.back();
2018 stack.pop_back();
2019 break;
2020 }
2021 }
2022
2023 if (defaultScript && !hasScript)
2024 readLinkerScript(mb: *defaultScript);
2025 if (files.empty() && !hasInput && errorCount() == 0)
2026 error(msg: "no input files");
2027}
2028
2029// If -m <machine_type> was not given, infer it from object files.
2030void LinkerDriver::inferMachineType() {
2031 if (config->ekind != ELFNoneKind)
2032 return;
2033
2034 bool inferred = false;
2035 for (InputFile *f : files) {
2036 if (f->ekind == ELFNoneKind)
2037 continue;
2038 if (!inferred) {
2039 inferred = true;
2040 config->ekind = f->ekind;
2041 config->emachine = f->emachine;
2042 config->mipsN32Abi = config->emachine == EM_MIPS && isMipsN32Abi(f);
2043 }
2044 config->osabi = f->osabi;
2045 if (f->osabi != ELFOSABI_NONE)
2046 return;
2047 }
2048 if (!inferred)
2049 error(msg: "target emulation unknown: -m or at least one .o file required");
2050}
2051
2052// Parse -z max-page-size=<value>. The default value is defined by
2053// each target.
2054static uint64_t getMaxPageSize(opt::InputArgList &args) {
2055 uint64_t val = args::getZOptionValue(args, id: OPT_z, key: "max-page-size",
2056 Default: target->defaultMaxPageSize);
2057 if (!isPowerOf2_64(Value: val)) {
2058 error(msg: "max-page-size: value isn't a power of 2");
2059 return target->defaultMaxPageSize;
2060 }
2061 if (config->nmagic || config->omagic) {
2062 if (val != target->defaultMaxPageSize)
2063 warn(msg: "-z max-page-size set, but paging disabled by omagic or nmagic");
2064 return 1;
2065 }
2066 return val;
2067}
2068
2069// Parse -z common-page-size=<value>. The default value is defined by
2070// each target.
2071static uint64_t getCommonPageSize(opt::InputArgList &args) {
2072 uint64_t val = args::getZOptionValue(args, id: OPT_z, key: "common-page-size",
2073 Default: target->defaultCommonPageSize);
2074 if (!isPowerOf2_64(Value: val)) {
2075 error(msg: "common-page-size: value isn't a power of 2");
2076 return target->defaultCommonPageSize;
2077 }
2078 if (config->nmagic || config->omagic) {
2079 if (val != target->defaultCommonPageSize)
2080 warn(msg: "-z common-page-size set, but paging disabled by omagic or nmagic");
2081 return 1;
2082 }
2083 // commonPageSize can't be larger than maxPageSize.
2084 if (val > config->maxPageSize)
2085 val = config->maxPageSize;
2086 return val;
2087}
2088
2089// Parses --image-base option.
2090static std::optional<uint64_t> getImageBase(opt::InputArgList &args) {
2091 // Because we are using "Config->maxPageSize" here, this function has to be
2092 // called after the variable is initialized.
2093 auto *arg = args.getLastArg(Ids: OPT_image_base);
2094 if (!arg)
2095 return std::nullopt;
2096
2097 StringRef s = arg->getValue();
2098 uint64_t v;
2099 if (!to_integer(S: s, Num&: v)) {
2100 error(msg: "--image-base: number expected, but got " + s);
2101 return 0;
2102 }
2103 if ((v % config->maxPageSize) != 0)
2104 warn(msg: "--image-base: address isn't multiple of page size: " + s);
2105 return v;
2106}
2107
2108// Parses `--exclude-libs=lib,lib,...`.
2109// The library names may be delimited by commas or colons.
2110static DenseSet<StringRef> getExcludeLibs(opt::InputArgList &args) {
2111 DenseSet<StringRef> ret;
2112 for (auto *arg : args.filtered(Ids: OPT_exclude_libs)) {
2113 StringRef s = arg->getValue();
2114 for (;;) {
2115 size_t pos = s.find_first_of(Chars: ",:");
2116 if (pos == StringRef::npos)
2117 break;
2118 ret.insert(V: s.substr(Start: 0, N: pos));
2119 s = s.substr(Start: pos + 1);
2120 }
2121 ret.insert(V: s);
2122 }
2123 return ret;
2124}
2125
2126// Handles the --exclude-libs option. If a static library file is specified
2127// by the --exclude-libs option, all public symbols from the archive become
2128// private unless otherwise specified by version scripts or something.
2129// A special library name "ALL" means all archive files.
2130//
2131// This is not a popular option, but some programs such as bionic libc use it.
2132static void excludeLibs(opt::InputArgList &args) {
2133 DenseSet<StringRef> libs = getExcludeLibs(args);
2134 bool all = libs.count(V: "ALL");
2135
2136 auto visit = [&](InputFile *file) {
2137 if (file->archiveName.empty() ||
2138 !(all || libs.count(V: path::filename(path: file->archiveName))))
2139 return;
2140 ArrayRef<Symbol *> symbols = file->getSymbols();
2141 if (isa<ELFFileBase>(Val: file))
2142 symbols = cast<ELFFileBase>(Val: file)->getGlobalSymbols();
2143 for (Symbol *sym : symbols)
2144 if (!sym->isUndefined() && sym->file == file)
2145 sym->versionId = VER_NDX_LOCAL;
2146 };
2147
2148 for (ELFFileBase *file : ctx.objectFiles)
2149 visit(file);
2150
2151 for (BitcodeFile *file : ctx.bitcodeFiles)
2152 visit(file);
2153}
2154
2155// Force Sym to be entered in the output.
2156static void handleUndefined(Symbol *sym, const char *option) {
2157 // Since a symbol may not be used inside the program, LTO may
2158 // eliminate it. Mark the symbol as "used" to prevent it.
2159 sym->isUsedInRegularObj = true;
2160
2161 if (!sym->isLazy())
2162 return;
2163 sym->extract();
2164 if (!config->whyExtract.empty())
2165 ctx.whyExtractRecords.emplace_back(Args&: option, Args&: sym->file, Args&: *sym);
2166}
2167
2168// As an extension to GNU linkers, lld supports a variant of `-u`
2169// which accepts wildcard patterns. All symbols that match a given
2170// pattern are handled as if they were given by `-u`.
2171static void handleUndefinedGlob(StringRef arg) {
2172 Expected<GlobPattern> pat = GlobPattern::create(Pat: arg);
2173 if (!pat) {
2174 error(msg: "--undefined-glob: " + toString(E: pat.takeError()) + ": " + arg);
2175 return;
2176 }
2177
2178 // Calling sym->extract() in the loop is not safe because it may add new
2179 // symbols to the symbol table, invalidating the current iterator.
2180 SmallVector<Symbol *, 0> syms;
2181 for (Symbol *sym : symtab.getSymbols())
2182 if (!sym->isPlaceholder() && pat->match(S: sym->getName()))
2183 syms.push_back(Elt: sym);
2184
2185 for (Symbol *sym : syms)
2186 handleUndefined(sym, option: "--undefined-glob");
2187}
2188
2189static void handleLibcall(StringRef name) {
2190 Symbol *sym = symtab.find(name);
2191 if (sym && sym->isLazy() && isa<BitcodeFile>(Val: sym->file)) {
2192 if (!config->whyExtract.empty())
2193 ctx.whyExtractRecords.emplace_back(Args: "<libcall>", Args&: sym->file, Args&: *sym);
2194 sym->extract();
2195 }
2196}
2197
2198static void writeArchiveStats() {
2199 if (config->printArchiveStats.empty())
2200 return;
2201
2202 std::error_code ec;
2203 raw_fd_ostream os = ctx.openAuxiliaryFile(filename: config->printArchiveStats, ec);
2204 if (ec) {
2205 error(msg: "--print-archive-stats=: cannot open " + config->printArchiveStats +
2206 ": " + ec.message());
2207 return;
2208 }
2209
2210 os << "members\textracted\tarchive\n";
2211
2212 SmallVector<StringRef, 0> archives;
2213 DenseMap<CachedHashStringRef, unsigned> all, extracted;
2214 for (ELFFileBase *file : ctx.objectFiles)
2215 if (file->archiveName.size())
2216 ++extracted[CachedHashStringRef(file->archiveName)];
2217 for (BitcodeFile *file : ctx.bitcodeFiles)
2218 if (file->archiveName.size())
2219 ++extracted[CachedHashStringRef(file->archiveName)];
2220 for (std::pair<StringRef, unsigned> f : ctx.driver.archiveFiles) {
2221 unsigned &v = extracted[CachedHashString(f.first)];
2222 os << f.second << '\t' << v << '\t' << f.first << '\n';
2223 // If the archive occurs multiple times, other instances have a count of 0.
2224 v = 0;
2225 }
2226}
2227
2228static void writeWhyExtract() {
2229 if (config->whyExtract.empty())
2230 return;
2231
2232 std::error_code ec;
2233 raw_fd_ostream os = ctx.openAuxiliaryFile(filename: config->whyExtract, ec);
2234 if (ec) {
2235 error(msg: "cannot open --why-extract= file " + config->whyExtract + ": " +
2236 ec.message());
2237 return;
2238 }
2239
2240 os << "reference\textracted\tsymbol\n";
2241 for (auto &entry : ctx.whyExtractRecords) {
2242 os << std::get<0>(t&: entry) << '\t' << toString(f: std::get<1>(t&: entry)) << '\t'
2243 << toString(std::get<2>(t&: entry)) << '\n';
2244 }
2245}
2246
2247static void reportBackrefs() {
2248 for (auto &ref : ctx.backwardReferences) {
2249 const Symbol &sym = *ref.first;
2250 std::string to = toString(f: ref.second.second);
2251 // Some libraries have known problems and can cause noise. Filter them out
2252 // with --warn-backrefs-exclude=. The value may look like (for --start-lib)
2253 // *.o or (archive member) *.a(*.o).
2254 bool exclude = false;
2255 for (const llvm::GlobPattern &pat : config->warnBackrefsExclude)
2256 if (pat.match(S: to)) {
2257 exclude = true;
2258 break;
2259 }
2260 if (!exclude)
2261 warn(msg: "backward reference detected: " + sym.getName() + " in " +
2262 toString(f: ref.second.first) + " refers to " + to);
2263 }
2264}
2265
2266// Handle --dependency-file=<path>. If that option is given, lld creates a
2267// file at a given path with the following contents:
2268//
2269// <output-file>: <input-file> ...
2270//
2271// <input-file>:
2272//
2273// where <output-file> is a pathname of an output file and <input-file>
2274// ... is a list of pathnames of all input files. `make` command can read a
2275// file in the above format and interpret it as a dependency info. We write
2276// phony targets for every <input-file> to avoid an error when that file is
2277// removed.
2278//
2279// This option is useful if you want to make your final executable to depend
2280// on all input files including system libraries. Here is why.
2281//
2282// When you write a Makefile, you usually write it so that the final
2283// executable depends on all user-generated object files. Normally, you
2284// don't make your executable to depend on system libraries (such as libc)
2285// because you don't know the exact paths of libraries, even though system
2286// libraries that are linked to your executable statically are technically a
2287// part of your program. By using --dependency-file option, you can make
2288// lld to dump dependency info so that you can maintain exact dependencies
2289// easily.
2290static void writeDependencyFile() {
2291 std::error_code ec;
2292 raw_fd_ostream os = ctx.openAuxiliaryFile(filename: config->dependencyFile, ec);
2293 if (ec) {
2294 error(msg: "cannot open " + config->dependencyFile + ": " + ec.message());
2295 return;
2296 }
2297
2298 // We use the same escape rules as Clang/GCC which are accepted by Make/Ninja:
2299 // * A space is escaped by a backslash which itself must be escaped.
2300 // * A hash sign is escaped by a single backslash.
2301 // * $ is escapes as $$.
2302 auto printFilename = [](raw_fd_ostream &os, StringRef filename) {
2303 llvm::SmallString<256> nativePath;
2304 llvm::sys::path::native(path: filename.str(), result&: nativePath);
2305 llvm::sys::path::remove_dots(path&: nativePath, /*remove_dot_dot=*/true);
2306 for (unsigned i = 0, e = nativePath.size(); i != e; ++i) {
2307 if (nativePath[i] == '#') {
2308 os << '\\';
2309 } else if (nativePath[i] == ' ') {
2310 os << '\\';
2311 unsigned j = i;
2312 while (j > 0 && nativePath[--j] == '\\')
2313 os << '\\';
2314 } else if (nativePath[i] == '$') {
2315 os << '$';
2316 }
2317 os << nativePath[i];
2318 }
2319 };
2320
2321 os << config->outputFile << ":";
2322 for (StringRef path : config->dependencyFiles) {
2323 os << " \\\n ";
2324 printFilename(os, path);
2325 }
2326 os << "\n";
2327
2328 for (StringRef path : config->dependencyFiles) {
2329 os << "\n";
2330 printFilename(os, path);
2331 os << ":\n";
2332 }
2333}
2334
2335// Replaces common symbols with defined symbols reside in .bss sections.
2336// This function is called after all symbol names are resolved. As a
2337// result, the passes after the symbol resolution won't see any
2338// symbols of type CommonSymbol.
2339static void replaceCommonSymbols() {
2340 llvm::TimeTraceScope timeScope("Replace common symbols");
2341 for (ELFFileBase *file : ctx.objectFiles) {
2342 if (!file->hasCommonSyms)
2343 continue;
2344 for (Symbol *sym : file->getGlobalSymbols()) {
2345 auto *s = dyn_cast<CommonSymbol>(Val: sym);
2346 if (!s)
2347 continue;
2348
2349 auto *bss = make<BssSection>(args: "COMMON", args&: s->size, args&: s->alignment);
2350 bss->file = s->file;
2351 ctx.inputSections.push_back(Elt: bss);
2352 Defined(s->file, StringRef(), s->binding, s->stOther, s->type,
2353 /*value=*/0, s->size, bss)
2354 .overwrite(sym&: *s);
2355 }
2356 }
2357}
2358
2359// The section referred to by `s` is considered address-significant. Set the
2360// keepUnique flag on the section if appropriate.
2361static void markAddrsig(Symbol *s) {
2362 if (auto *d = dyn_cast_or_null<Defined>(Val: s))
2363 if (d->section)
2364 // We don't need to keep text sections unique under --icf=all even if they
2365 // are address-significant.
2366 if (config->icf == ICFLevel::Safe || !(d->section->flags & SHF_EXECINSTR))
2367 d->section->keepUnique = true;
2368}
2369
2370// Record sections that define symbols mentioned in --keep-unique <symbol>
2371// and symbols referred to by address-significance tables. These sections are
2372// ineligible for ICF.
2373template <class ELFT>
2374static void findKeepUniqueSections(opt::InputArgList &args) {
2375 for (auto *arg : args.filtered(Ids: OPT_keep_unique)) {
2376 StringRef name = arg->getValue();
2377 auto *d = dyn_cast_or_null<Defined>(Val: symtab.find(name));
2378 if (!d || !d->section) {
2379 warn(msg: "could not find symbol " + name + " to keep unique");
2380 continue;
2381 }
2382 d->section->keepUnique = true;
2383 }
2384
2385 // --icf=all --ignore-data-address-equality means that we can ignore
2386 // the dynsym and address-significance tables entirely.
2387 if (config->icf == ICFLevel::All && config->ignoreDataAddressEquality)
2388 return;
2389
2390 // Symbols in the dynsym could be address-significant in other executables
2391 // or DSOs, so we conservatively mark them as address-significant.
2392 for (Symbol *sym : symtab.getSymbols())
2393 if (sym->includeInDynsym())
2394 markAddrsig(s: sym);
2395
2396 // Visit the address-significance table in each object file and mark each
2397 // referenced symbol as address-significant.
2398 for (InputFile *f : ctx.objectFiles) {
2399 auto *obj = cast<ObjFile<ELFT>>(f);
2400 ArrayRef<Symbol *> syms = obj->getSymbols();
2401 if (obj->addrsigSec) {
2402 ArrayRef<uint8_t> contents =
2403 check(obj->getObj().getSectionContents(*obj->addrsigSec));
2404 const uint8_t *cur = contents.begin();
2405 while (cur != contents.end()) {
2406 unsigned size;
2407 const char *err = nullptr;
2408 uint64_t symIndex = decodeULEB128(p: cur, n: &size, end: contents.end(), error: &err);
2409 if (err)
2410 fatal(msg: toString(f) + ": could not decode addrsig section: " + err);
2411 markAddrsig(s: syms[symIndex]);
2412 cur += size;
2413 }
2414 } else {
2415 // If an object file does not have an address-significance table,
2416 // conservatively mark all of its symbols as address-significant.
2417 for (Symbol *s : syms)
2418 markAddrsig(s);
2419 }
2420 }
2421}
2422
2423// This function reads a symbol partition specification section. These sections
2424// are used to control which partition a symbol is allocated to. See
2425// https://lld.llvm.org/Partitions.html for more details on partitions.
2426template <typename ELFT>
2427static void readSymbolPartitionSection(InputSectionBase *s) {
2428 // Read the relocation that refers to the partition's entry point symbol.
2429 Symbol *sym;
2430 const RelsOrRelas<ELFT> rels = s->template relsOrRelas<ELFT>();
2431 if (rels.areRelocsRel())
2432 sym = &s->file->getRelocTargetSym(rels.rels[0]);
2433 else
2434 sym = &s->file->getRelocTargetSym(rels.relas[0]);
2435 if (!isa<Defined>(Val: sym) || !sym->includeInDynsym())
2436 return;
2437
2438 StringRef partName = reinterpret_cast<const char *>(s->content().data());
2439 for (Partition &part : partitions) {
2440 if (part.name == partName) {
2441 sym->partition = part.getNumber();
2442 return;
2443 }
2444 }
2445
2446 // Forbid partitions from being used on incompatible targets, and forbid them
2447 // from being used together with various linker features that assume a single
2448 // set of output sections.
2449 if (script->hasSectionsCommand)
2450 error(msg: toString(f: s->file) +
2451 ": partitions cannot be used with the SECTIONS command");
2452 if (script->hasPhdrsCommands())
2453 error(msg: toString(f: s->file) +
2454 ": partitions cannot be used with the PHDRS command");
2455 if (!config->sectionStartMap.empty())
2456 error(msg: toString(f: s->file) + ": partitions cannot be used with "
2457 "--section-start, -Ttext, -Tdata or -Tbss");
2458 if (config->emachine == EM_MIPS)
2459 error(msg: toString(f: s->file) + ": partitions cannot be used on this target");
2460
2461 // Impose a limit of no more than 254 partitions. This limit comes from the
2462 // sizes of the Partition fields in InputSectionBase and Symbol, as well as
2463 // the amount of space devoted to the partition number in RankFlags.
2464 if (partitions.size() == 254)
2465 fatal(msg: "may not have more than 254 partitions");
2466
2467 partitions.emplace_back();
2468 Partition &newPart = partitions.back();
2469 newPart.name = partName;
2470 sym->partition = newPart.getNumber();
2471}
2472
2473static void markBuffersAsDontNeed(bool skipLinkedOutput) {
2474 // With --thinlto-index-only, all buffers are nearly unused from now on
2475 // (except symbol/section names used by infrequent passes). Mark input file
2476 // buffers as MADV_DONTNEED so that these pages can be reused by the expensive
2477 // thin link, saving memory.
2478 if (skipLinkedOutput) {
2479 for (MemoryBuffer &mb : llvm::make_pointee_range(Range&: ctx.memoryBuffers))
2480 mb.dontNeedIfMmap();
2481 return;
2482 }
2483
2484 // Otherwise, just mark MemoryBuffers backing BitcodeFiles.
2485 DenseSet<const char *> bufs;
2486 for (BitcodeFile *file : ctx.bitcodeFiles)
2487 bufs.insert(V: file->mb.getBufferStart());
2488 for (BitcodeFile *file : ctx.lazyBitcodeFiles)
2489 bufs.insert(V: file->mb.getBufferStart());
2490 for (MemoryBuffer &mb : llvm::make_pointee_range(Range&: ctx.memoryBuffers))
2491 if (bufs.count(V: mb.getBufferStart()))
2492 mb.dontNeedIfMmap();
2493}
2494
2495// This function is where all the optimizations of link-time
2496// optimization takes place. When LTO is in use, some input files are
2497// not in native object file format but in the LLVM bitcode format.
2498// This function compiles bitcode files into a few big native files
2499// using LLVM functions and replaces bitcode symbols with the results.
2500// Because all bitcode files that the program consists of are passed to
2501// the compiler at once, it can do a whole-program optimization.
2502template <class ELFT>
2503void LinkerDriver::compileBitcodeFiles(bool skipLinkedOutput) {
2504 llvm::TimeTraceScope timeScope("LTO");
2505 // Compile bitcode files and replace bitcode symbols.
2506 lto.reset(p: new BitcodeCompiler);
2507 for (BitcodeFile *file : ctx.bitcodeFiles)
2508 lto->add(f&: *file);
2509
2510 if (!ctx.bitcodeFiles.empty())
2511 markBuffersAsDontNeed(skipLinkedOutput);
2512
2513 for (InputFile *file : lto->compile()) {
2514 auto *obj = cast<ObjFile<ELFT>>(file);
2515 obj->parse(/*ignoreComdats=*/true);
2516
2517 // Parse '@' in symbol names for non-relocatable output.
2518 if (!config->relocatable)
2519 for (Symbol *sym : obj->getGlobalSymbols())
2520 if (sym->hasVersionSuffix)
2521 sym->parseSymbolVersion();
2522 ctx.objectFiles.push_back(Elt: obj);
2523 }
2524}
2525
2526// The --wrap option is a feature to rename symbols so that you can write
2527// wrappers for existing functions. If you pass `--wrap=foo`, all
2528// occurrences of symbol `foo` are resolved to `__wrap_foo` (so, you are
2529// expected to write `__wrap_foo` function as a wrapper). The original
2530// symbol becomes accessible as `__real_foo`, so you can call that from your
2531// wrapper.
2532//
2533// This data structure is instantiated for each --wrap option.
2534struct WrappedSymbol {
2535 Symbol *sym;
2536 Symbol *real;
2537 Symbol *wrap;
2538};
2539
2540// Handles --wrap option.
2541//
2542// This function instantiates wrapper symbols. At this point, they seem
2543// like they are not being used at all, so we explicitly set some flags so
2544// that LTO won't eliminate them.
2545static std::vector<WrappedSymbol> addWrappedSymbols(opt::InputArgList &args) {
2546 std::vector<WrappedSymbol> v;
2547 DenseSet<StringRef> seen;
2548
2549 for (auto *arg : args.filtered(Ids: OPT_wrap)) {
2550 StringRef name = arg->getValue();
2551 if (!seen.insert(V: name).second)
2552 continue;
2553
2554 Symbol *sym = symtab.find(name);
2555 if (!sym)
2556 continue;
2557
2558 Symbol *wrap =
2559 symtab.addUnusedUndefined(name: saver().save(S: "__wrap_" + name), binding: sym->binding);
2560
2561 // If __real_ is referenced, pull in the symbol if it is lazy. Do this after
2562 // processing __wrap_ as that may have referenced __real_.
2563 StringRef realName = saver().save(S: "__real_" + name);
2564 if (Symbol *real = symtab.find(name: realName)) {
2565 symtab.addUnusedUndefined(name, binding: sym->binding);
2566 // Update sym's binding, which will replace real's later in
2567 // SymbolTable::wrap.
2568 sym->binding = real->binding;
2569 }
2570
2571 Symbol *real = symtab.addUnusedUndefined(name: realName);
2572 v.push_back(x: {.sym: sym, .real: real, .wrap: wrap});
2573
2574 // We want to tell LTO not to inline symbols to be overwritten
2575 // because LTO doesn't know the final symbol contents after renaming.
2576 real->scriptDefined = true;
2577 sym->scriptDefined = true;
2578
2579 // If a symbol is referenced in any object file, bitcode file or shared
2580 // object, mark its redirection target (foo for __real_foo and __wrap_foo
2581 // for foo) as referenced after redirection, which will be used to tell LTO
2582 // to not eliminate the redirection target. If the object file defining the
2583 // symbol also references it, we cannot easily distinguish the case from
2584 // cases where the symbol is not referenced. Retain the redirection target
2585 // in this case because we choose to wrap symbol references regardless of
2586 // whether the symbol is defined
2587 // (https://sourceware.org/bugzilla/show_bug.cgi?id=26358).
2588 if (real->referenced || real->isDefined())
2589 sym->referencedAfterWrap = true;
2590 if (sym->referenced || sym->isDefined())
2591 wrap->referencedAfterWrap = true;
2592 }
2593 return v;
2594}
2595
2596static void combineVersionedSymbol(Symbol &sym,
2597 DenseMap<Symbol *, Symbol *> &map) {
2598 const char *suffix1 = sym.getVersionSuffix();
2599 if (suffix1[0] != '@' || suffix1[1] == '@')
2600 return;
2601
2602 // Check the existing symbol foo. We have two special cases to handle:
2603 //
2604 // * There is a definition of foo@v1 and foo@@v1.
2605 // * There is a definition of foo@v1 and foo.
2606 Defined *sym2 = dyn_cast_or_null<Defined>(Val: symtab.find(name: sym.getName()));
2607 if (!sym2)
2608 return;
2609 const char *suffix2 = sym2->getVersionSuffix();
2610 if (suffix2[0] == '@' && suffix2[1] == '@' &&
2611 strcmp(s1: suffix1 + 1, s2: suffix2 + 2) == 0) {
2612 // foo@v1 and foo@@v1 should be merged, so redirect foo@v1 to foo@@v1.
2613 map.try_emplace(Key: &sym, Args&: sym2);
2614 // If both foo@v1 and foo@@v1 are defined and non-weak, report a
2615 // duplicate definition error.
2616 if (sym.isDefined()) {
2617 sym2->checkDuplicate(other: cast<Defined>(Val&: sym));
2618 sym2->resolve(other: cast<Defined>(Val&: sym));
2619 } else if (sym.isUndefined()) {
2620 sym2->resolve(other: cast<Undefined>(Val&: sym));
2621 } else {
2622 sym2->resolve(other: cast<SharedSymbol>(Val&: sym));
2623 }
2624 // Eliminate foo@v1 from the symbol table.
2625 sym.symbolKind = Symbol::PlaceholderKind;
2626 sym.isUsedInRegularObj = false;
2627 } else if (auto *sym1 = dyn_cast<Defined>(Val: &sym)) {
2628 if (sym2->versionId > VER_NDX_GLOBAL
2629 ? config->versionDefinitions[sym2->versionId].name == suffix1 + 1
2630 : sym1->section == sym2->section && sym1->value == sym2->value) {
2631 // Due to an assembler design flaw, if foo is defined, .symver foo,
2632 // foo@v1 defines both foo and foo@v1. Unless foo is bound to a
2633 // different version, GNU ld makes foo@v1 canonical and eliminates
2634 // foo. Emulate its behavior, otherwise we would have foo or foo@@v1
2635 // beside foo@v1. foo@v1 and foo combining does not apply if they are
2636 // not defined in the same place.
2637 map.try_emplace(Key: sym2, Args: &sym);
2638 sym2->symbolKind = Symbol::PlaceholderKind;
2639 sym2->isUsedInRegularObj = false;
2640 }
2641 }
2642}
2643
2644// Do renaming for --wrap and foo@v1 by updating pointers to symbols.
2645//
2646// When this function is executed, only InputFiles and symbol table
2647// contain pointers to symbol objects. We visit them to replace pointers,
2648// so that wrapped symbols are swapped as instructed by the command line.
2649static void redirectSymbols(ArrayRef<WrappedSymbol> wrapped) {
2650 llvm::TimeTraceScope timeScope("Redirect symbols");
2651 DenseMap<Symbol *, Symbol *> map;
2652 for (const WrappedSymbol &w : wrapped) {
2653 map[w.sym] = w.wrap;
2654 map[w.real] = w.sym;
2655 }
2656
2657 // If there are version definitions (versionDefinitions.size() > 2), enumerate
2658 // symbols with a non-default version (foo@v1) and check whether it should be
2659 // combined with foo or foo@@v1.
2660 if (config->versionDefinitions.size() > 2)
2661 for (Symbol *sym : symtab.getSymbols())
2662 if (sym->hasVersionSuffix)
2663 combineVersionedSymbol(sym&: *sym, map);
2664
2665 if (map.empty())
2666 return;
2667
2668 // Update pointers in input files.
2669 parallelForEach(R&: ctx.objectFiles, Fn: [&](ELFFileBase *file) {
2670 for (Symbol *&sym : file->getMutableGlobalSymbols())
2671 if (Symbol *s = map.lookup(Val: sym))
2672 sym = s;
2673 });
2674
2675 // Update pointers in the symbol table.
2676 for (const WrappedSymbol &w : wrapped)
2677 symtab.wrap(sym: w.sym, real: w.real, wrap: w.wrap);
2678}
2679
2680static void reportMissingFeature(StringRef config, const Twine &report) {
2681 if (config == "error")
2682 error(msg: report);
2683 else if (config == "warning")
2684 warn(msg: report);
2685}
2686
2687static void checkAndReportMissingFeature(StringRef config, uint32_t features,
2688 uint32_t mask, const Twine &report) {
2689 if (!(features & mask))
2690 reportMissingFeature(config, report);
2691}
2692
2693// To enable CET (x86's hardware-assisted control flow enforcement), each
2694// source file must be compiled with -fcf-protection. Object files compiled
2695// with the flag contain feature flags indicating that they are compatible
2696// with CET. We enable the feature only when all object files are compatible
2697// with CET.
2698//
2699// This is also the case with AARCH64's BTI and PAC which use the similar
2700// GNU_PROPERTY_AARCH64_FEATURE_1_AND mechanism.
2701//
2702// For AArch64 PAuth-enabled object files, the core info of all of them must
2703// match. Missing info for some object files with matching info for remaining
2704// ones can be allowed (see -z pauth-report).
2705static void readSecurityNotes() {
2706 if (config->emachine != EM_386 && config->emachine != EM_X86_64 &&
2707 config->emachine != EM_AARCH64)
2708 return;
2709
2710 config->andFeatures = -1;
2711
2712 StringRef referenceFileName;
2713 if (config->emachine == EM_AARCH64) {
2714 auto it = llvm::find_if(Range&: ctx.objectFiles, P: [](const ELFFileBase *f) {
2715 return !f->aarch64PauthAbiCoreInfo.empty();
2716 });
2717 if (it != ctx.objectFiles.end()) {
2718 ctx.aarch64PauthAbiCoreInfo = (*it)->aarch64PauthAbiCoreInfo;
2719 referenceFileName = (*it)->getName();
2720 }
2721 }
2722
2723 for (ELFFileBase *f : ctx.objectFiles) {
2724 uint32_t features = f->andFeatures;
2725
2726 checkAndReportMissingFeature(
2727 config: config->zBtiReport, features, mask: GNU_PROPERTY_AARCH64_FEATURE_1_BTI,
2728 report: toString(f) + ": -z bti-report: file does not have "
2729 "GNU_PROPERTY_AARCH64_FEATURE_1_BTI property");
2730
2731 checkAndReportMissingFeature(
2732 config: config->zGcsReport, features, mask: GNU_PROPERTY_AARCH64_FEATURE_1_GCS,
2733 report: toString(f) + ": -z gcs-report: file does not have "
2734 "GNU_PROPERTY_AARCH64_FEATURE_1_GCS property");
2735
2736 checkAndReportMissingFeature(
2737 config: config->zCetReport, features, mask: GNU_PROPERTY_X86_FEATURE_1_IBT,
2738 report: toString(f) + ": -z cet-report: file does not have "
2739 "GNU_PROPERTY_X86_FEATURE_1_IBT property");
2740
2741 checkAndReportMissingFeature(
2742 config: config->zCetReport, features, mask: GNU_PROPERTY_X86_FEATURE_1_SHSTK,
2743 report: toString(f) + ": -z cet-report: file does not have "
2744 "GNU_PROPERTY_X86_FEATURE_1_SHSTK property");
2745
2746 if (config->zForceBti && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)) {
2747 features |= GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
2748 if (config->zBtiReport == "none")
2749 warn(msg: toString(f) + ": -z force-bti: file does not have "
2750 "GNU_PROPERTY_AARCH64_FEATURE_1_BTI property");
2751 } else if (config->zForceIbt &&
2752 !(features & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
2753 if (config->zCetReport == "none")
2754 warn(msg: toString(f) + ": -z force-ibt: file does not have "
2755 "GNU_PROPERTY_X86_FEATURE_1_IBT property");
2756 features |= GNU_PROPERTY_X86_FEATURE_1_IBT;
2757 }
2758 if (config->zPacPlt && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_PAC)) {
2759 warn(msg: toString(f) + ": -z pac-plt: file does not have "
2760 "GNU_PROPERTY_AARCH64_FEATURE_1_PAC property");
2761 features |= GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
2762 }
2763 config->andFeatures &= features;
2764
2765 if (ctx.aarch64PauthAbiCoreInfo.empty())
2766 continue;
2767
2768 if (f->aarch64PauthAbiCoreInfo.empty()) {
2769 reportMissingFeature(config: config->zPauthReport,
2770 report: toString(f) +
2771 ": -z pauth-report: file does not have AArch64 "
2772 "PAuth core info while '" +
2773 referenceFileName + "' has one");
2774 continue;
2775 }
2776
2777 if (ctx.aarch64PauthAbiCoreInfo != f->aarch64PauthAbiCoreInfo)
2778 errorOrWarn(msg: "incompatible values of AArch64 PAuth core info found\n>>> " +
2779 referenceFileName + ": 0x" +
2780 toHex(Input: ctx.aarch64PauthAbiCoreInfo, /*LowerCase=*/true) +
2781 "\n>>> " + toString(f) + ": 0x" +
2782 toHex(Input: f->aarch64PauthAbiCoreInfo, /*LowerCase=*/true));
2783 }
2784
2785 // Force enable Shadow Stack.
2786 if (config->zShstk)
2787 config->andFeatures |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
2788
2789 // Force enable/disable GCS
2790 if (config->zGcs == GcsPolicy::Always)
2791 config->andFeatures |= GNU_PROPERTY_AARCH64_FEATURE_1_GCS;
2792 else if (config->zGcs == GcsPolicy::Never)
2793 config->andFeatures &= ~GNU_PROPERTY_AARCH64_FEATURE_1_GCS;
2794}
2795
2796static void initSectionsAndLocalSyms(ELFFileBase *file, bool ignoreComdats) {
2797 switch (file->ekind) {
2798 case ELF32LEKind:
2799 cast<ObjFile<ELF32LE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
2800 break;
2801 case ELF32BEKind:
2802 cast<ObjFile<ELF32BE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
2803 break;
2804 case ELF64LEKind:
2805 cast<ObjFile<ELF64LE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
2806 break;
2807 case ELF64BEKind:
2808 cast<ObjFile<ELF64BE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
2809 break;
2810 default:
2811 llvm_unreachable("");
2812 }
2813}
2814
2815static void postParseObjectFile(ELFFileBase *file) {
2816 switch (file->ekind) {
2817 case ELF32LEKind:
2818 cast<ObjFile<ELF32LE>>(Val: file)->postParse();
2819 break;
2820 case ELF32BEKind:
2821 cast<ObjFile<ELF32BE>>(Val: file)->postParse();
2822 break;
2823 case ELF64LEKind:
2824 cast<ObjFile<ELF64LE>>(Val: file)->postParse();
2825 break;
2826 case ELF64BEKind:
2827 cast<ObjFile<ELF64BE>>(Val: file)->postParse();
2828 break;
2829 default:
2830 llvm_unreachable("");
2831 }
2832}
2833
2834// Do actual linking. Note that when this function is called,
2835// all linker scripts have already been parsed.
2836template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
2837 llvm::TimeTraceScope timeScope("Link", StringRef("LinkerDriver::Link"));
2838
2839 // Handle --trace-symbol.
2840 for (auto *arg : args.filtered(Ids: OPT_trace_symbol))
2841 symtab.insert(name: arg->getValue())->traced = true;
2842
2843 ctx.internalFile = createInternalFile(name: "<internal>");
2844
2845 // Handle -u/--undefined before input files. If both a.a and b.so define foo,
2846 // -u foo a.a b.so will extract a.a.
2847 for (StringRef name : config->undefined)
2848 symtab.addUnusedUndefined(name)->referenced = true;
2849
2850 parseFiles(files, armCmseImpLib);
2851
2852 // Create dynamic sections for dynamic linking and static PIE.
2853 config->hasDynSymTab = !ctx.sharedFiles.empty() || config->isPic;
2854
2855 // If an entry symbol is in a static archive, pull out that file now.
2856 if (Symbol *sym = symtab.find(name: config->entry))
2857 handleUndefined(sym, option: "--entry");
2858
2859 // Handle the `--undefined-glob <pattern>` options.
2860 for (StringRef pat : args::getStrings(args, id: OPT_undefined_glob))
2861 handleUndefinedGlob(arg: pat);
2862
2863 // After potential archive member extraction involving ENTRY and
2864 // -u/--undefined-glob, check whether PROVIDE symbols should be defined (the
2865 // RHS may refer to definitions in just extracted object files).
2866 script->addScriptReferencedSymbolsToSymTable();
2867
2868 // Prevent LTO from removing any definition referenced by -u.
2869 for (StringRef name : config->undefined)
2870 if (Defined *sym = dyn_cast_or_null<Defined>(Val: symtab.find(name)))
2871 sym->isUsedInRegularObj = true;
2872
2873 // Mark -init and -fini symbols so that the LTO doesn't eliminate them.
2874 if (Symbol *sym = dyn_cast_or_null<Defined>(Val: symtab.find(name: config->init)))
2875 sym->isUsedInRegularObj = true;
2876 if (Symbol *sym = dyn_cast_or_null<Defined>(Val: symtab.find(name: config->fini)))
2877 sym->isUsedInRegularObj = true;
2878
2879 // If any of our inputs are bitcode files, the LTO code generator may create
2880 // references to certain library functions that might not be explicit in the
2881 // bitcode file's symbol table. If any of those library functions are defined
2882 // in a bitcode file in an archive member, we need to arrange to use LTO to
2883 // compile those archive members by adding them to the link beforehand.
2884 //
2885 // However, adding all libcall symbols to the link can have undesired
2886 // consequences. For example, the libgcc implementation of
2887 // __sync_val_compare_and_swap_8 on 32-bit ARM pulls in an .init_array entry
2888 // that aborts the program if the Linux kernel does not support 64-bit
2889 // atomics, which would prevent the program from running even if it does not
2890 // use 64-bit atomics.
2891 //
2892 // Therefore, we only add libcall symbols to the link before LTO if we have
2893 // to, i.e. if the symbol's definition is in bitcode. Any other required
2894 // libcall symbols will be added to the link after LTO when we add the LTO
2895 // object file to the link.
2896 if (!ctx.bitcodeFiles.empty()) {
2897 llvm::Triple TT(ctx.bitcodeFiles.front()->obj->getTargetTriple());
2898 for (auto *s : lto::LTO::getRuntimeLibcallSymbols(TT))
2899 handleLibcall(name: s);
2900 }
2901
2902 // Archive members defining __wrap symbols may be extracted.
2903 std::vector<WrappedSymbol> wrapped = addWrappedSymbols(args);
2904
2905 // No more lazy bitcode can be extracted at this point. Do post parse work
2906 // like checking duplicate symbols.
2907 parallelForEach(ctx.objectFiles, [](ELFFileBase *file) {
2908 initSectionsAndLocalSyms(file, /*ignoreComdats=*/false);
2909 });
2910 parallelForEach(R&: ctx.objectFiles, Fn: postParseObjectFile);
2911 parallelForEach(ctx.bitcodeFiles,
2912 [](BitcodeFile *file) { file->postParse(); });
2913 for (auto &it : ctx.nonPrevailingSyms) {
2914 Symbol &sym = *it.first;
2915 Undefined(sym.file, sym.getName(), sym.binding, sym.stOther, sym.type,
2916 it.second)
2917 .overwrite(sym);
2918 cast<Undefined>(Val&: sym).nonPrevailing = true;
2919 }
2920 ctx.nonPrevailingSyms.clear();
2921 for (const DuplicateSymbol &d : ctx.duplicates)
2922 reportDuplicate(sym: *d.sym, newFile: d.file, errSec: d.section, errOffset: d.value);
2923 ctx.duplicates.clear();
2924
2925 // Return if there were name resolution errors.
2926 if (errorCount())
2927 return;
2928
2929 // We want to declare linker script's symbols early,
2930 // so that we can version them.
2931 // They also might be exported if referenced by DSOs.
2932 script->declareSymbols();
2933
2934 // Handle --exclude-libs. This is before scanVersionScript() due to a
2935 // workaround for Android ndk: for a defined versioned symbol in an archive
2936 // without a version node in the version script, Android does not expect a
2937 // 'has undefined version' error in -shared --exclude-libs=ALL mode (PR36295).
2938 // GNU ld errors in this case.
2939 if (args.hasArg(Ids: OPT_exclude_libs))
2940 excludeLibs(args);
2941
2942 // Create elfHeader early. We need a dummy section in
2943 // addReservedSymbols to mark the created symbols as not absolute.
2944 Out::elfHeader = make<OutputSection>(args: "", args: 0, args: SHF_ALLOC);
2945
2946 // We need to create some reserved symbols such as _end. Create them.
2947 if (!config->relocatable)
2948 addReservedSymbols();
2949
2950 // Apply version scripts.
2951 //
2952 // For a relocatable output, version scripts don't make sense, and
2953 // parsing a symbol version string (e.g. dropping "@ver1" from a symbol
2954 // name "foo@ver1") rather do harm, so we don't call this if -r is given.
2955 if (!config->relocatable) {
2956 llvm::TimeTraceScope timeScope("Process symbol versions");
2957 symtab.scanVersionScript();
2958 }
2959
2960 // Skip the normal linked output if some LTO options are specified.
2961 //
2962 // For --thinlto-index-only, index file creation is performed in
2963 // compileBitcodeFiles, so we are done afterwards. --plugin-opt=emit-llvm and
2964 // --plugin-opt=emit-asm create output files in bitcode or assembly code,
2965 // respectively. When only certain thinLTO modules are specified for
2966 // compilation, the intermediate object file are the expected output.
2967 const bool skipLinkedOutput = config->thinLTOIndexOnly || config->emitLLVM ||
2968 config->ltoEmitAsm ||
2969 !config->thinLTOModulesToCompile.empty();
2970
2971 // Handle --lto-validate-all-vtables-have-type-infos.
2972 if (config->ltoValidateAllVtablesHaveTypeInfos)
2973 ltoValidateAllVtablesHaveTypeInfos<ELFT>(args);
2974
2975 // Do link-time optimization if given files are LLVM bitcode files.
2976 // This compiles bitcode files into real object files.
2977 //
2978 // With this the symbol table should be complete. After this, no new names
2979 // except a few linker-synthesized ones will be added to the symbol table.
2980 const size_t numObjsBeforeLTO = ctx.objectFiles.size();
2981 const size_t numInputFilesBeforeLTO = ctx.driver.files.size();
2982 compileBitcodeFiles<ELFT>(skipLinkedOutput);
2983
2984 // Symbol resolution finished. Report backward reference problems,
2985 // --print-archive-stats=, and --why-extract=.
2986 reportBackrefs();
2987 writeArchiveStats();
2988 writeWhyExtract();
2989 if (errorCount())
2990 return;
2991
2992 // Bail out if normal linked output is skipped due to LTO.
2993 if (skipLinkedOutput)
2994 return;
2995
2996 // compileBitcodeFiles may have produced lto.tmp object files. After this, no
2997 // more file will be added.
2998 auto newObjectFiles = ArrayRef(ctx.objectFiles).slice(N: numObjsBeforeLTO);
2999 parallelForEach(newObjectFiles, [](ELFFileBase *file) {
3000 initSectionsAndLocalSyms(file, /*ignoreComdats=*/true);
3001 });
3002 parallelForEach(R&: newObjectFiles, Fn: postParseObjectFile);
3003 for (const DuplicateSymbol &d : ctx.duplicates)
3004 reportDuplicate(sym: *d.sym, newFile: d.file, errSec: d.section, errOffset: d.value);
3005
3006 // ELF dependent libraries may have introduced new input files after LTO has
3007 // completed. This is an error if the files haven't already been parsed, since
3008 // changing the symbol table could break the semantic assumptions of LTO.
3009 auto newInputFiles = ArrayRef(ctx.driver.files).slice(N: numInputFilesBeforeLTO);
3010 if (!newInputFiles.empty()) {
3011 DenseSet<StringRef> oldFilenames;
3012 for (InputFile *f :
3013 ArrayRef(ctx.driver.files).slice(N: 0, M: numInputFilesBeforeLTO))
3014 oldFilenames.insert(V: f->getName());
3015 for (InputFile *newFile : newInputFiles)
3016 if (!oldFilenames.contains(V: newFile->getName()))
3017 errorOrWarn(msg: "input file '" + newFile->getName() + "' added after LTO");
3018 }
3019
3020 // Handle --exclude-libs again because lto.tmp may reference additional
3021 // libcalls symbols defined in an excluded archive. This may override
3022 // versionId set by scanVersionScript().
3023 if (args.hasArg(Ids: OPT_exclude_libs))
3024 excludeLibs(args);
3025
3026 // Record [__acle_se_<sym>, <sym>] pairs for later processing.
3027 processArmCmseSymbols();
3028
3029 // Apply symbol renames for --wrap and combine foo@v1 and foo@@v1.
3030 redirectSymbols(wrapped);
3031
3032 // Replace common symbols with regular symbols.
3033 replaceCommonSymbols();
3034
3035 {
3036 llvm::TimeTraceScope timeScope("Aggregate sections");
3037 // Now that we have a complete list of input files.
3038 // Beyond this point, no new files are added.
3039 // Aggregate all input sections into one place.
3040 for (InputFile *f : ctx.objectFiles) {
3041 for (InputSectionBase *s : f->getSections()) {
3042 if (!s || s == &InputSection::discarded)
3043 continue;
3044 if (LLVM_UNLIKELY(isa<EhInputSection>(s)))
3045 ctx.ehInputSections.push_back(Elt: cast<EhInputSection>(Val: s));
3046 else
3047 ctx.inputSections.push_back(Elt: s);
3048 }
3049 }
3050 for (BinaryFile *f : ctx.binaryFiles)
3051 for (InputSectionBase *s : f->getSections())
3052 ctx.inputSections.push_back(Elt: cast<InputSection>(Val: s));
3053 }
3054
3055 {
3056 llvm::TimeTraceScope timeScope("Strip sections");
3057 if (ctx.hasSympart.load(m: std::memory_order_relaxed)) {
3058 llvm::erase_if(ctx.inputSections, [](InputSectionBase *s) {
3059 if (s->type != SHT_LLVM_SYMPART)
3060 return false;
3061 readSymbolPartitionSection<ELFT>(s);
3062 return true;
3063 });
3064 }
3065 // We do not want to emit debug sections if --strip-all
3066 // or --strip-debug are given.
3067 if (config->strip != StripPolicy::None) {
3068 llvm::erase_if(ctx.inputSections, [](InputSectionBase *s) {
3069 if (isDebugSection(sec: *s))
3070 return true;
3071 if (auto *isec = dyn_cast<InputSection>(Val: s))
3072 if (InputSectionBase *rel = isec->getRelocatedSection())
3073 if (isDebugSection(sec: *rel))
3074 return true;
3075
3076 return false;
3077 });
3078 }
3079 }
3080
3081 // Since we now have a complete set of input files, we can create
3082 // a .d file to record build dependencies.
3083 if (!config->dependencyFile.empty())
3084 writeDependencyFile();
3085
3086 // Now that the number of partitions is fixed, save a pointer to the main
3087 // partition.
3088 mainPart = &partitions[0];
3089
3090 // Read .note.gnu.property sections from input object files which
3091 // contain a hint to tweak linker's and loader's behaviors.
3092 readSecurityNotes();
3093
3094 // The Target instance handles target-specific stuff, such as applying
3095 // relocations or writing a PLT section. It also contains target-dependent
3096 // values such as a default image base address.
3097 target = getTarget();
3098
3099 config->eflags = target->calcEFlags();
3100 // maxPageSize (sometimes called abi page size) is the maximum page size that
3101 // the output can be run on. For example if the OS can use 4k or 64k page
3102 // sizes then maxPageSize must be 64k for the output to be useable on both.
3103 // All important alignment decisions must use this value.
3104 config->maxPageSize = getMaxPageSize(args);
3105 // commonPageSize is the most common page size that the output will be run on.
3106 // For example if an OS can use 4k or 64k page sizes and 4k is more common
3107 // than 64k then commonPageSize is set to 4k. commonPageSize can be used for
3108 // optimizations such as DATA_SEGMENT_ALIGN in linker scripts. LLD's use of it
3109 // is limited to writing trap instructions on the last executable segment.
3110 config->commonPageSize = getCommonPageSize(args);
3111
3112 config->imageBase = getImageBase(args);
3113
3114 // This adds a .comment section containing a version string.
3115 if (!config->relocatable)
3116 ctx.inputSections.push_back(Elt: createCommentSection());
3117
3118 // Split SHF_MERGE and .eh_frame sections into pieces in preparation for garbage collection.
3119 splitSections<ELFT>();
3120
3121 // Garbage collection and removal of shared symbols from unused shared objects.
3122 markLive<ELFT>();
3123
3124 // Make copies of any input sections that need to be copied into each
3125 // partition.
3126 copySectionsIntoPartitions();
3127
3128 if (canHaveMemtagGlobals()) {
3129 llvm::TimeTraceScope timeScope("Process memory tagged symbols");
3130 createTaggedSymbols(files: ctx.objectFiles);
3131 }
3132
3133 // Create synthesized sections such as .got and .plt. This is called before
3134 // processSectionCommands() so that they can be placed by SECTIONS commands.
3135 createSyntheticSections<ELFT>();
3136
3137 // Some input sections that are used for exception handling need to be moved
3138 // into synthetic sections. Do that now so that they aren't assigned to
3139 // output sections in the usual way.
3140 if (!config->relocatable)
3141 combineEhSections();
3142
3143 // Merge .riscv.attributes sections.
3144 if (config->emachine == EM_RISCV)
3145 mergeRISCVAttributesSections();
3146
3147 {
3148 llvm::TimeTraceScope timeScope("Assign sections");
3149
3150 // Create output sections described by SECTIONS commands.
3151 script->processSectionCommands();
3152
3153 // Linker scripts control how input sections are assigned to output
3154 // sections. Input sections that were not handled by scripts are called
3155 // "orphans", and they are assigned to output sections by the default rule.
3156 // Process that.
3157 script->addOrphanSections();
3158 }
3159
3160 {
3161 llvm::TimeTraceScope timeScope("Merge/finalize input sections");
3162
3163 // Migrate InputSectionDescription::sectionBases to sections. This includes
3164 // merging MergeInputSections into a single MergeSyntheticSection. From this
3165 // point onwards InputSectionDescription::sections should be used instead of
3166 // sectionBases.
3167 for (SectionCommand *cmd : script->sectionCommands)
3168 if (auto *osd = dyn_cast<OutputDesc>(Val: cmd))
3169 osd->osec.finalizeInputSections(script: &script.s);
3170 }
3171
3172 // Two input sections with different output sections should not be folded.
3173 // ICF runs after processSectionCommands() so that we know the output sections.
3174 if (config->icf != ICFLevel::None) {
3175 findKeepUniqueSections<ELFT>(args);
3176 doIcf<ELFT>();
3177 }
3178
3179 // Read the callgraph now that we know what was gced or icfed
3180 if (config->callGraphProfileSort != CGProfileSortKind::None) {
3181 if (auto *arg = args.getLastArg(Ids: OPT_call_graph_ordering_file))
3182 if (std::optional<MemoryBufferRef> buffer = readFile(path: arg->getValue()))
3183 readCallGraph(mb: *buffer);
3184 readCallGraphsFromObjectFiles<ELFT>();
3185 }
3186
3187 // Write the result to the file.
3188 writeResult<ELFT>();
3189}
3190