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/ErrorHandler.h"
43#include "lld/Common/Filesystem.h"
44#include "lld/Common/Memory.h"
45#include "lld/Common/Strings.h"
46#include "lld/Common/Version.h"
47#include "llvm/ADT/STLExtras.h"
48#include "llvm/ADT/SetVector.h"
49#include "llvm/ADT/StringExtras.h"
50#include "llvm/ADT/StringSwitch.h"
51#include "llvm/Config/llvm-config.h"
52#include "llvm/LTO/LTO.h"
53#include "llvm/Object/Archive.h"
54#include "llvm/Object/IRObjectFile.h"
55#include "llvm/Remarks/HotnessThresholdParser.h"
56#include "llvm/Support/CommandLine.h"
57#include "llvm/Support/Compression.h"
58#include "llvm/Support/FileSystem.h"
59#include "llvm/Support/GlobPattern.h"
60#include "llvm/Support/LEB128.h"
61#include "llvm/Support/Parallel.h"
62#include "llvm/Support/Path.h"
63#include "llvm/Support/SaveAndRestore.h"
64#include "llvm/Support/TarWriter.h"
65#include "llvm/Support/TargetSelect.h"
66#include "llvm/Support/TimeProfiler.h"
67#include "llvm/Support/raw_ostream.h"
68#include <cstdlib>
69#include <tuple>
70#include <utility>
71
72using namespace llvm;
73using namespace llvm::ELF;
74using namespace llvm::object;
75using namespace llvm::sys;
76using namespace llvm::support;
77using namespace lld;
78using namespace lld::elf;
79
80static void setConfigs(Ctx &ctx, opt::InputArgList &args);
81static void readConfigs(Ctx &ctx, opt::InputArgList &args);
82
83ELFSyncStream elf::Log(Ctx &ctx) { return {ctx, DiagLevel::Log}; }
84ELFSyncStream elf::Msg(Ctx &ctx) { return {ctx, DiagLevel::Msg}; }
85ELFSyncStream elf::Warn(Ctx &ctx) { return {ctx, DiagLevel::Warn}; }
86ELFSyncStream elf::Err(Ctx &ctx) {
87 return {ctx, ctx.arg.noinhibitExec ? DiagLevel::Warn : DiagLevel::Err};
88}
89ELFSyncStream elf::ErrAlways(Ctx &ctx) { return {ctx, DiagLevel::Err}; }
90ELFSyncStream elf::Fatal(Ctx &ctx) { return {ctx, DiagLevel::Fatal}; }
91uint64_t elf::errCount(Ctx &ctx) { return ctx.e.errorCount; }
92
93ELFSyncStream elf::InternalErr(Ctx &ctx, const uint8_t *buf) {
94 ELFSyncStream s(ctx, DiagLevel::Err);
95 s << "internal linker error: ";
96 return s;
97}
98
99Ctx::Ctx() : driver(*this) {}
100
101llvm::raw_fd_ostream Ctx::openAuxiliaryFile(llvm::StringRef filename,
102 std::error_code &ec) {
103 using namespace llvm::sys::fs;
104 OpenFlags flags =
105 auxiliaryFiles.insert(V: filename).second ? OF_None : OF_Append;
106 if (e.disableOutput && filename == "-") {
107#ifdef _WIN32
108 filename = "NUL";
109#else
110 filename = "/dev/null";
111#endif
112 }
113 return {filename, ec, flags};
114}
115
116namespace lld {
117namespace elf {
118bool link(ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
119 llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput) {
120 // This driver-specific context will be freed later by unsafeLldMain().
121 auto *context = new Ctx;
122 Ctx &ctx = *context;
123
124 context->e.initialize(stdoutOS, stderrOS, exitEarly, disableOutput);
125 context->e.logName = args::getFilenameWithoutExe(path: args[0]);
126 context->e.errorLimitExceededMsg =
127 "too many errors emitted, stopping now (use "
128 "--error-limit=0 to see all errors)";
129
130 LinkerScript script(ctx);
131 ctx.script = &script;
132 ctx.symAux.emplace_back();
133 ctx.symtab = std::make_unique<SymbolTable>(args&: ctx);
134
135 ctx.partitions.clear();
136 ctx.partitions.emplace_back(args&: ctx);
137
138 ctx.arg.progName = args[0];
139
140 ctx.driver.linkerMain(args);
141
142 return errCount(ctx) == 0;
143}
144} // namespace elf
145} // namespace lld
146
147// Parses a linker -m option.
148static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(Ctx &ctx,
149 StringRef emul) {
150 uint8_t osabi = 0;
151 StringRef s = emul;
152 if (s.ends_with(Suffix: "_fbsd")) {
153 s = s.drop_back(N: 5);
154 osabi = ELFOSABI_FREEBSD;
155 }
156
157 std::pair<ELFKind, uint16_t> ret =
158 StringSwitch<std::pair<ELFKind, uint16_t>>(s)
159 .Cases(S0: "aarch64elf", S1: "aarch64linux", Value: {ELF64LEKind, EM_AARCH64})
160 .Cases(S0: "aarch64elfb", S1: "aarch64linuxb", Value: {ELF64BEKind, EM_AARCH64})
161 .Cases(S0: "armelf", S1: "armelf_linux_eabi", Value: {ELF32LEKind, EM_ARM})
162 .Cases(S0: "armelfb", S1: "armelfb_linux_eabi", Value: {ELF32BEKind, EM_ARM})
163 .Case(S: "elf32_x86_64", Value: {ELF32LEKind, EM_X86_64})
164 .Cases(S0: "elf32btsmip", S1: "elf32btsmipn32", Value: {ELF32BEKind, EM_MIPS})
165 .Cases(S0: "elf32ltsmip", S1: "elf32ltsmipn32", Value: {ELF32LEKind, EM_MIPS})
166 .Case(S: "elf32lriscv", Value: {ELF32LEKind, EM_RISCV})
167 .Cases(S0: "elf32ppc", S1: "elf32ppclinux", Value: {ELF32BEKind, EM_PPC})
168 .Cases(S0: "elf32lppc", S1: "elf32lppclinux", Value: {ELF32LEKind, EM_PPC})
169 .Case(S: "elf32loongarch", Value: {ELF32LEKind, EM_LOONGARCH})
170 .Case(S: "elf64btsmip", Value: {ELF64BEKind, EM_MIPS})
171 .Case(S: "elf64ltsmip", Value: {ELF64LEKind, EM_MIPS})
172 .Case(S: "elf64lriscv", Value: {ELF64LEKind, EM_RISCV})
173 .Case(S: "elf64ppc", Value: {ELF64BEKind, EM_PPC64})
174 .Case(S: "elf64lppc", Value: {ELF64LEKind, EM_PPC64})
175 .Cases(S0: "elf_amd64", S1: "elf_x86_64", Value: {ELF64LEKind, EM_X86_64})
176 .Case(S: "elf_i386", Value: {ELF32LEKind, EM_386})
177 .Case(S: "elf_iamcu", Value: {ELF32LEKind, EM_IAMCU})
178 .Case(S: "elf64_sparc", Value: {ELF64BEKind, EM_SPARCV9})
179 .Case(S: "msp430elf", Value: {ELF32LEKind, EM_MSP430})
180 .Case(S: "elf64_amdgpu", Value: {ELF64LEKind, EM_AMDGPU})
181 .Case(S: "elf64loongarch", Value: {ELF64LEKind, EM_LOONGARCH})
182 .Case(S: "elf64_s390", Value: {ELF64BEKind, EM_S390})
183 .Case(S: "hexagonelf", Value: {ELF32LEKind, EM_HEXAGON})
184 .Default(Value: {ELFNoneKind, EM_NONE});
185
186 if (ret.first == ELFNoneKind)
187 ErrAlways(ctx) << "unknown emulation: " << emul;
188 if (ret.second == EM_MSP430)
189 osabi = ELFOSABI_STANDALONE;
190 else if (ret.second == EM_AMDGPU)
191 osabi = ELFOSABI_AMDGPU_HSA;
192 return std::make_tuple(args&: ret.first, args&: ret.second, args&: osabi);
193}
194
195// Returns slices of MB by parsing MB as an archive file.
196// Each slice consists of a member file in the archive.
197std::vector<std::pair<MemoryBufferRef, uint64_t>> static getArchiveMembers(
198 Ctx &ctx, MemoryBufferRef mb) {
199 std::unique_ptr<Archive> file =
200 CHECK(Archive::create(mb),
201 mb.getBufferIdentifier() + ": failed to parse archive");
202
203 std::vector<std::pair<MemoryBufferRef, uint64_t>> v;
204 Error err = Error::success();
205 bool addToTar = file->isThin() && ctx.tar;
206 for (const Archive::Child &c : file->children(Err&: err)) {
207 MemoryBufferRef mbref =
208 CHECK(c.getMemoryBufferRef(),
209 mb.getBufferIdentifier() +
210 ": could not get the buffer for a child of the archive");
211 if (addToTar)
212 ctx.tar->append(Path: relativeToRoot(path: check(e: c.getFullName())),
213 Data: mbref.getBuffer());
214 v.push_back(x: std::make_pair(x&: mbref, y: c.getChildOffset()));
215 }
216 if (err)
217 Fatal(ctx) << mb.getBufferIdentifier()
218 << ": Archive::children failed: " << std::move(err);
219
220 // Take ownership of memory buffers created for members of thin archives.
221 std::vector<std::unique_ptr<MemoryBuffer>> mbs = file->takeThinBuffers();
222 std::move(first: mbs.begin(), last: mbs.end(), result: std::back_inserter(x&: ctx.memoryBuffers));
223
224 return v;
225}
226
227static bool isBitcode(MemoryBufferRef mb) {
228 return identify_magic(magic: mb.getBuffer()) == llvm::file_magic::bitcode;
229}
230
231bool LinkerDriver::tryAddFatLTOFile(MemoryBufferRef mb, StringRef archiveName,
232 uint64_t offsetInArchive, bool lazy) {
233 if (!ctx.arg.fatLTOObjects)
234 return false;
235 Expected<MemoryBufferRef> fatLTOData =
236 IRObjectFile::findBitcodeInMemBuffer(Object: mb);
237 if (errorToBool(Err: fatLTOData.takeError()))
238 return false;
239 files.push_back(Elt: std::make_unique<BitcodeFile>(args&: ctx, args&: *fatLTOData, args&: archiveName,
240 args&: offsetInArchive, args&: lazy));
241 return true;
242}
243
244// Opens a file and create a file object. Path has to be resolved already.
245void LinkerDriver::addFile(StringRef path, bool withLOption) {
246 using namespace sys::fs;
247
248 std::optional<MemoryBufferRef> buffer = readFile(ctx, path);
249 if (!buffer)
250 return;
251 MemoryBufferRef mbref = *buffer;
252
253 if (ctx.arg.formatBinary) {
254 files.push_back(Elt: std::make_unique<BinaryFile>(args&: ctx, args&: mbref));
255 return;
256 }
257
258 switch (identify_magic(magic: mbref.getBuffer())) {
259 case file_magic::unknown:
260 readLinkerScript(ctx, mb: mbref);
261 return;
262 case file_magic::archive: {
263 auto members = getArchiveMembers(ctx, mb: mbref);
264 if (inWholeArchive) {
265 for (const std::pair<MemoryBufferRef, uint64_t> &p : members) {
266 if (isBitcode(mb: p.first))
267 files.push_back(Elt: std::make_unique<BitcodeFile>(args&: ctx, args: p.first, args&: path,
268 args: p.second, args: false));
269 else if (!tryAddFatLTOFile(mb: p.first, archiveName: path, offsetInArchive: p.second, lazy: false))
270 files.push_back(Elt: createObjFile(ctx, mb: p.first, archiveName: path));
271 }
272 return;
273 }
274
275 archiveFiles.emplace_back(Args&: path, Args: members.size());
276
277 // Handle archives and --start-lib/--end-lib using the same code path. This
278 // scans all the ELF relocatable object files and bitcode files in the
279 // archive rather than just the index file, with the benefit that the
280 // symbols are only loaded once. For many projects archives see high
281 // utilization rates and it is a net performance win. --start-lib scans
282 // symbols in the same order that llvm-ar adds them to the index, so in the
283 // common case the semantics are identical. If the archive symbol table was
284 // created in a different order, or is incomplete, this strategy has
285 // different semantics. Such output differences are considered user error.
286 //
287 // All files within the archive get the same group ID to allow mutual
288 // references for --warn-backrefs.
289 SaveAndRestore saved(isInGroup, true);
290 for (const std::pair<MemoryBufferRef, uint64_t> &p : members) {
291 auto magic = identify_magic(magic: p.first.getBuffer());
292 if (magic == file_magic::elf_relocatable) {
293 if (!tryAddFatLTOFile(mb: p.first, archiveName: path, offsetInArchive: p.second, lazy: true))
294 files.push_back(Elt: createObjFile(ctx, mb: p.first, archiveName: path, lazy: true));
295 } else if (magic == file_magic::bitcode)
296 files.push_back(
297 Elt: std::make_unique<BitcodeFile>(args&: ctx, args: p.first, args&: path, args: p.second, args: true));
298 else
299 Warn(ctx) << path << ": archive member '"
300 << p.first.getBufferIdentifier()
301 << "' is neither ET_REL nor LLVM bitcode";
302 }
303 if (!saved.get())
304 ++nextGroupId;
305 return;
306 }
307 case file_magic::elf_shared_object: {
308 if (ctx.arg.isStatic) {
309 ErrAlways(ctx) << "attempted static link of dynamic object " << path;
310 return;
311 }
312
313 // Shared objects are identified by soname. soname is (if specified)
314 // DT_SONAME and falls back to filename. If a file was specified by -lfoo,
315 // the directory part is ignored. Note that path may be a temporary and
316 // cannot be stored into SharedFile::soName.
317 path = mbref.getBufferIdentifier();
318 auto f = std::make_unique<SharedFile>(
319 args&: ctx, args&: mbref, args: withLOption ? path::filename(path) : path);
320 f->init();
321 files.push_back(Elt: std::move(f));
322 return;
323 }
324 case file_magic::bitcode:
325 files.push_back(Elt: std::make_unique<BitcodeFile>(args&: ctx, args&: mbref, args: "", args: 0, args&: inLib));
326 break;
327 case file_magic::elf_relocatable:
328 if (!tryAddFatLTOFile(mb: mbref, archiveName: "", offsetInArchive: 0, lazy: inLib))
329 files.push_back(Elt: createObjFile(ctx, mb: mbref, archiveName: "", lazy: inLib));
330 break;
331 default:
332 ErrAlways(ctx) << path << ": unknown file type";
333 }
334}
335
336// Add a given library by searching it from input search paths.
337void LinkerDriver::addLibrary(StringRef name) {
338 if (std::optional<std::string> path = searchLibrary(ctx, path: name))
339 addFile(path: ctx.saver.save(S: *path), /*withLOption=*/true);
340 else
341 ctx.e.error(msg: "unable to find library -l" + name, tag: ErrorTag::LibNotFound,
342 args: {name});
343}
344
345// This function is called on startup. We need this for LTO since
346// LTO calls LLVM functions to compile bitcode files to native code.
347// Technically this can be delayed until we read bitcode files, but
348// we don't bother to do lazily because the initialization is fast.
349static void initLLVM() {
350 InitializeAllTargets();
351 InitializeAllTargetMCs();
352 InitializeAllAsmPrinters();
353 InitializeAllAsmParsers();
354}
355
356// Some command line options or some combinations of them are not allowed.
357// This function checks for such errors.
358static void checkOptions(Ctx &ctx) {
359 // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
360 // table which is a relatively new feature.
361 if (ctx.arg.emachine == EM_MIPS && ctx.arg.gnuHash)
362 ErrAlways(ctx)
363 << "the .gnu.hash section is not compatible with the MIPS target";
364
365 if (ctx.arg.emachine == EM_ARM) {
366 if (!ctx.arg.cmseImplib) {
367 if (!ctx.arg.cmseInputLib.empty())
368 ErrAlways(ctx) << "--in-implib may not be used without --cmse-implib";
369 if (!ctx.arg.cmseOutputLib.empty())
370 ErrAlways(ctx) << "--out-implib may not be used without --cmse-implib";
371 }
372 if (ctx.arg.fixCortexA8 && !ctx.arg.isLE)
373 ErrAlways(ctx)
374 << "--fix-cortex-a8 is not supported on big endian targets";
375 } else {
376 if (ctx.arg.cmseImplib)
377 ErrAlways(ctx) << "--cmse-implib is only supported on ARM targets";
378 if (!ctx.arg.cmseInputLib.empty())
379 ErrAlways(ctx) << "--in-implib is only supported on ARM targets";
380 if (!ctx.arg.cmseOutputLib.empty())
381 ErrAlways(ctx) << "--out-implib is only supported on ARM targets";
382 if (ctx.arg.fixCortexA8)
383 ErrAlways(ctx) << "--fix-cortex-a8 is only supported on ARM targets";
384 if (ctx.arg.armBe8)
385 ErrAlways(ctx) << "--be8 is only supported on ARM targets";
386 }
387
388 if (ctx.arg.emachine != EM_AARCH64) {
389 if (ctx.arg.executeOnly)
390 ErrAlways(ctx) << "--execute-only is only supported on AArch64 targets";
391 if (ctx.arg.fixCortexA53Errata843419)
392 ErrAlways(ctx) << "--fix-cortex-a53-843419 is only supported on AArch64";
393 if (ctx.arg.zPacPlt)
394 ErrAlways(ctx) << "-z pac-plt only supported on AArch64";
395 if (ctx.arg.zForceBti)
396 ErrAlways(ctx) << "-z force-bti only supported on AArch64";
397 if (ctx.arg.zBtiReport != ReportPolicy::None)
398 ErrAlways(ctx) << "-z bti-report only supported on AArch64";
399 if (ctx.arg.zPauthReport != ReportPolicy::None)
400 ErrAlways(ctx) << "-z pauth-report only supported on AArch64";
401 if (ctx.arg.zGcsReport != ReportPolicy::None)
402 ErrAlways(ctx) << "-z gcs-report only supported on AArch64";
403 if (ctx.arg.zGcsReportDynamic != ReportPolicy::None)
404 ErrAlways(ctx) << "-z gcs-report-dynamic only supported on AArch64";
405 if (ctx.arg.zGcs != GcsPolicy::Implicit)
406 ErrAlways(ctx) << "-z gcs only supported on AArch64";
407 }
408
409 if (ctx.arg.emachine != EM_AARCH64 && ctx.arg.emachine != EM_ARM &&
410 ctx.arg.zExecuteOnlyReport != ReportPolicy::None)
411 ErrAlways(ctx)
412 << "-z execute-only-report only supported on AArch64 and ARM";
413
414 if (ctx.arg.emachine != EM_PPC64) {
415 if (ctx.arg.tocOptimize)
416 ErrAlways(ctx) << "--toc-optimize is only supported on PowerPC64 targets";
417 if (ctx.arg.pcRelOptimize)
418 ErrAlways(ctx)
419 << "--pcrel-optimize is only supported on PowerPC64 targets";
420 }
421
422 if (ctx.arg.emachine != EM_RISCV) {
423 if (ctx.arg.relaxGP)
424 ErrAlways(ctx) << "--relax-gp is only supported on RISC-V targets";
425 if (ctx.arg.zZicfilpUnlabeledReport != ReportPolicy::None)
426 ErrAlways(ctx) << "-z zicfilip-unlabeled-report is only supported on "
427 "RISC-V targets";
428 if (ctx.arg.zZicfilpFuncSigReport != ReportPolicy::None)
429 ErrAlways(ctx) << "-z zicfilip-func-sig-report is only supported on "
430 "RISC-V targets";
431 if (ctx.arg.zZicfissReport != ReportPolicy::None)
432 ErrAlways(ctx) << "-z zicfiss-report is only supported on RISC-V targets";
433 if (ctx.arg.zZicfilp != ZicfilpPolicy::Implicit)
434 ErrAlways(ctx) << "-z zicfilp is only supported on RISC-V targets";
435 if (ctx.arg.zZicfiss != ZicfissPolicy::Implicit)
436 ErrAlways(ctx) << "-z zicfiss is only supported on RISC-V targets";
437 }
438
439 if (ctx.arg.emachine != EM_386 && ctx.arg.emachine != EM_X86_64 &&
440 ctx.arg.zCetReport != ReportPolicy::None)
441 ErrAlways(ctx) << "-z cet-report only supported on X86 and X86_64";
442
443 if (ctx.arg.pie && ctx.arg.shared)
444 ErrAlways(ctx) << "-shared and -pie may not be used together";
445
446 if (!ctx.arg.shared && !ctx.arg.filterList.empty())
447 ErrAlways(ctx) << "-F may not be used without -shared";
448
449 if (!ctx.arg.shared && !ctx.arg.auxiliaryList.empty())
450 ErrAlways(ctx) << "-f may not be used without -shared";
451
452 if (ctx.arg.strip == StripPolicy::All && ctx.arg.emitRelocs)
453 ErrAlways(ctx) << "--strip-all and --emit-relocs may not be used together";
454
455 if (ctx.arg.zText && ctx.arg.zIfuncNoplt)
456 ErrAlways(ctx) << "-z text and -z ifunc-noplt may not be used together";
457
458 if (ctx.arg.relocatable) {
459 if (ctx.arg.shared)
460 ErrAlways(ctx) << "-r and -shared may not be used together";
461 if (ctx.arg.gdbIndex)
462 ErrAlways(ctx) << "-r and --gdb-index may not be used together";
463 if (ctx.arg.icf != ICFLevel::None)
464 ErrAlways(ctx) << "-r and --icf may not be used together";
465 if (ctx.arg.pie)
466 ErrAlways(ctx) << "-r and -pie may not be used together";
467 if (ctx.arg.exportDynamic)
468 ErrAlways(ctx) << "-r and --export-dynamic may not be used together";
469 if (ctx.arg.debugNames)
470 ErrAlways(ctx) << "-r and --debug-names may not be used together";
471 if (!ctx.arg.zSectionHeader)
472 ErrAlways(ctx) << "-r and -z nosectionheader may not be used together";
473 }
474
475 if (ctx.arg.executeOnly) {
476 if (ctx.arg.singleRoRx && !ctx.script->hasSectionsCommand)
477 ErrAlways(ctx)
478 << "--execute-only and --no-rosegment cannot be used together";
479 }
480
481 if (ctx.arg.zRetpolineplt && ctx.arg.zForceIbt)
482 ErrAlways(ctx) << "-z force-ibt may not be used with -z retpolineplt";
483}
484
485static const char *getReproduceOption(opt::InputArgList &args) {
486 if (auto *arg = args.getLastArg(Ids: OPT_reproduce))
487 return arg->getValue();
488 return getenv(name: "LLD_REPRODUCE");
489}
490
491static bool hasZOption(opt::InputArgList &args, StringRef key) {
492 bool ret = false;
493 for (auto *arg : args.filtered(Ids: OPT_z))
494 if (key == arg->getValue()) {
495 ret = true;
496 arg->claim();
497 }
498 return ret;
499}
500
501static bool getZFlag(opt::InputArgList &args, StringRef k1, StringRef k2,
502 bool defaultValue) {
503 for (auto *arg : args.filtered(Ids: OPT_z)) {
504 StringRef v = arg->getValue();
505 if (k1 == v)
506 defaultValue = true;
507 else if (k2 == v)
508 defaultValue = false;
509 else
510 continue;
511 arg->claim();
512 }
513 return defaultValue;
514}
515
516static SeparateSegmentKind getZSeparate(opt::InputArgList &args) {
517 auto ret = SeparateSegmentKind::None;
518 for (auto *arg : args.filtered(Ids: OPT_z)) {
519 StringRef v = arg->getValue();
520 if (v == "noseparate-code")
521 ret = SeparateSegmentKind::None;
522 else if (v == "separate-code")
523 ret = SeparateSegmentKind::Code;
524 else if (v == "separate-loadable-segments")
525 ret = SeparateSegmentKind::Loadable;
526 else
527 continue;
528 arg->claim();
529 }
530 return ret;
531}
532
533static GnuStackKind getZGnuStack(opt::InputArgList &args) {
534 auto ret = GnuStackKind::NoExec;
535 for (auto *arg : args.filtered(Ids: OPT_z)) {
536 StringRef v = arg->getValue();
537 if (v == "execstack")
538 ret = GnuStackKind::Exec;
539 else if (v == "noexecstack")
540 ret = GnuStackKind::NoExec;
541 else if (v == "nognustack")
542 ret = GnuStackKind::None;
543 else
544 continue;
545 arg->claim();
546 }
547 return ret;
548}
549
550static uint8_t getZStartStopVisibility(Ctx &ctx, opt::InputArgList &args) {
551 uint8_t ret = STV_PROTECTED;
552 for (auto *arg : args.filtered(Ids: OPT_z)) {
553 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
554 if (kv.first == "start-stop-visibility") {
555 arg->claim();
556 if (kv.second == "default")
557 ret = STV_DEFAULT;
558 else if (kv.second == "internal")
559 ret = STV_INTERNAL;
560 else if (kv.second == "hidden")
561 ret = STV_HIDDEN;
562 else if (kv.second == "protected")
563 ret = STV_PROTECTED;
564 else
565 ErrAlways(ctx) << "unknown -z start-stop-visibility= value: "
566 << StringRef(kv.second);
567 }
568 }
569 return ret;
570}
571
572static GcsPolicy getZGcs(Ctx &ctx, opt::InputArgList &args) {
573 GcsPolicy ret = GcsPolicy::Implicit;
574 for (auto *arg : args.filtered(Ids: OPT_z)) {
575 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
576 if (kv.first == "gcs") {
577 arg->claim();
578 if (kv.second == "implicit")
579 ret = GcsPolicy::Implicit;
580 else if (kv.second == "never")
581 ret = GcsPolicy::Never;
582 else if (kv.second == "always")
583 ret = GcsPolicy::Always;
584 else
585 ErrAlways(ctx) << "unknown -z gcs= value: " << kv.second;
586 }
587 }
588 return ret;
589}
590
591static ZicfilpPolicy getZZicfilp(Ctx &ctx, opt::InputArgList &args) {
592 auto ret = ZicfilpPolicy::Implicit;
593 for (auto *arg : args.filtered(Ids: OPT_z)) {
594 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
595 if (kv.first == "zicfilp") {
596 arg->claim();
597 if (kv.second == "unlabeled")
598 ret = ZicfilpPolicy::Unlabeled;
599 else if (kv.second == "func-sig")
600 ret = ZicfilpPolicy::FuncSig;
601 else if (kv.second == "never")
602 ret = ZicfilpPolicy::Never;
603 else if (kv.second == "implicit")
604 ret = ZicfilpPolicy::Implicit;
605 else
606 ErrAlways(ctx) << "unknown -z zicfilp= value: " << kv.second;
607 }
608 }
609 return ret;
610}
611
612static ZicfissPolicy getZZicfiss(Ctx &ctx, opt::InputArgList &args) {
613 auto ret = ZicfissPolicy::Implicit;
614 for (auto *arg : args.filtered(Ids: OPT_z)) {
615 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
616 if (kv.first == "zicfiss") {
617 arg->claim();
618 if (kv.second == "always")
619 ret = ZicfissPolicy::Always;
620 else if (kv.second == "never")
621 ret = ZicfissPolicy::Never;
622 else if (kv.second == "implicit")
623 ret = ZicfissPolicy::Implicit;
624 else
625 ErrAlways(ctx) << "unknown -z zicfiss= value: " << kv.second;
626 }
627 }
628 return ret;
629}
630
631// Report a warning for an unknown -z option.
632static void checkZOptions(Ctx &ctx, opt::InputArgList &args) {
633 // This function is called before getTarget(), when certain options are not
634 // initialized yet. Claim them here.
635 args::getZOptionValue(args, id: OPT_z, key: "max-page-size", Default: 0);
636 args::getZOptionValue(args, id: OPT_z, key: "common-page-size", Default: 0);
637 getZFlag(args, k1: "rel", k2: "rela", defaultValue: false);
638 getZFlag(args, k1: "dynamic-undefined-weak", k2: "nodynamic-undefined-weak", defaultValue: false);
639 for (auto *arg : args.filtered(Ids: OPT_z))
640 if (!arg->isClaimed())
641 Warn(ctx) << "unknown -z value: " << StringRef(arg->getValue());
642}
643
644constexpr const char *saveTempsValues[] = {
645 "resolution", "preopt", "promote", "internalize", "import",
646 "opt", "precodegen", "prelink", "combinedindex"};
647
648LinkerDriver::LinkerDriver(Ctx &ctx) : ctx(ctx) {}
649
650void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
651 ELFOptTable parser;
652 opt::InputArgList args = parser.parse(ctx, argv: argsArr.slice(N: 1));
653
654 // Interpret these flags early because Err/Warn depend on them.
655 ctx.e.errorLimit = args::getInteger(args, key: OPT_error_limit, Default: 20);
656 ctx.e.fatalWarnings =
657 args.hasFlag(Pos: OPT_fatal_warnings, Neg: OPT_no_fatal_warnings, Default: false) &&
658 !args.hasArg(Ids: OPT_no_warnings);
659 ctx.e.suppressWarnings = args.hasArg(Ids: OPT_no_warnings);
660
661 // Handle -help
662 if (args.hasArg(Ids: OPT_help)) {
663 printHelp(ctx);
664 return;
665 }
666
667 // Handle -v or -version.
668 //
669 // A note about "compatible with GNU linkers" message: this is a hack for
670 // scripts generated by GNU Libtool up to 2021-10 to recognize LLD as
671 // a GNU compatible linker. See
672 // <https://lists.gnu.org/archive/html/libtool/2017-01/msg00007.html>.
673 //
674 // This is somewhat ugly hack, but in reality, we had no choice other
675 // than doing this. Considering the very long release cycle of Libtool,
676 // it is not easy to improve it to recognize LLD as a GNU compatible
677 // linker in a timely manner. Even if we can make it, there are still a
678 // lot of "configure" scripts out there that are generated by old version
679 // of Libtool. We cannot convince every software developer to migrate to
680 // the latest version and re-generate scripts. So we have this hack.
681 if (args.hasArg(Ids: OPT_v) || args.hasArg(Ids: OPT_version))
682 Msg(ctx) << getLLDVersion() << " (compatible with GNU linkers)";
683
684 if (const char *path = getReproduceOption(args)) {
685 // Note that --reproduce is a debug option so you can ignore it
686 // if you are trying to understand the whole picture of the code.
687 Expected<std::unique_ptr<TarWriter>> errOrWriter =
688 TarWriter::create(OutputPath: path, BaseDir: path::stem(path));
689 if (errOrWriter) {
690 ctx.tar = std::move(*errOrWriter);
691 ctx.tar->append(Path: "response.txt", Data: createResponseFile(args));
692 ctx.tar->append(Path: "version.txt", Data: getLLDVersion() + "\n");
693 StringRef ltoSampleProfile = args.getLastArgValue(Id: OPT_lto_sample_profile);
694 if (!ltoSampleProfile.empty())
695 readFile(ctx, path: ltoSampleProfile);
696 } else {
697 ErrAlways(ctx) << "--reproduce: " << errOrWriter.takeError();
698 }
699 }
700
701 readConfigs(ctx, args);
702 checkZOptions(ctx, args);
703
704 // The behavior of -v or --version is a bit strange, but this is
705 // needed for compatibility with GNU linkers.
706 if (args.hasArg(Ids: OPT_v) && !args.hasArg(Ids: OPT_INPUT))
707 return;
708 if (args.hasArg(Ids: OPT_version))
709 return;
710
711 // Initialize time trace profiler.
712 if (ctx.arg.timeTraceEnabled)
713 timeTraceProfilerInitialize(TimeTraceGranularity: ctx.arg.timeTraceGranularity, ProcName: ctx.arg.progName);
714
715 {
716 llvm::TimeTraceScope timeScope("ExecuteLinker");
717
718 initLLVM();
719 createFiles(args);
720 if (errCount(ctx))
721 return;
722
723 inferMachineType();
724 setConfigs(ctx, args);
725 checkOptions(ctx);
726 if (errCount(ctx))
727 return;
728
729 invokeELFT(link, args);
730 }
731
732 if (ctx.arg.timeTraceEnabled) {
733 checkError(eh&: ctx.e, e: timeTraceProfilerWrite(
734 PreferredFileName: args.getLastArgValue(Id: OPT_time_trace_eq).str(),
735 FallbackFileName: ctx.arg.outputFile));
736 timeTraceProfilerCleanup();
737 }
738}
739
740static std::string getRpath(opt::InputArgList &args) {
741 SmallVector<StringRef, 0> v = args::getStrings(args, id: OPT_rpath);
742 return llvm::join(Begin: v.begin(), End: v.end(), Separator: ":");
743}
744
745// Determines what we should do if there are remaining unresolved
746// symbols after the name resolution.
747static void setUnresolvedSymbolPolicy(Ctx &ctx, opt::InputArgList &args) {
748 UnresolvedPolicy errorOrWarn = args.hasFlag(Pos: OPT_error_unresolved_symbols,
749 Neg: OPT_warn_unresolved_symbols, Default: true)
750 ? UnresolvedPolicy::ReportError
751 : UnresolvedPolicy::Warn;
752 // -shared implies --unresolved-symbols=ignore-all because missing
753 // symbols are likely to be resolved at runtime.
754 bool diagRegular = !ctx.arg.shared, diagShlib = !ctx.arg.shared;
755
756 for (const opt::Arg *arg : args) {
757 switch (arg->getOption().getID()) {
758 case OPT_unresolved_symbols: {
759 StringRef s = arg->getValue();
760 if (s == "ignore-all") {
761 diagRegular = false;
762 diagShlib = false;
763 } else if (s == "ignore-in-object-files") {
764 diagRegular = false;
765 diagShlib = true;
766 } else if (s == "ignore-in-shared-libs") {
767 diagRegular = true;
768 diagShlib = false;
769 } else if (s == "report-all") {
770 diagRegular = true;
771 diagShlib = true;
772 } else {
773 ErrAlways(ctx) << "unknown --unresolved-symbols value: " << s;
774 }
775 break;
776 }
777 case OPT_no_undefined:
778 diagRegular = true;
779 break;
780 case OPT_z:
781 if (StringRef(arg->getValue()) == "defs")
782 diagRegular = true;
783 else if (StringRef(arg->getValue()) == "undefs")
784 diagRegular = false;
785 else
786 break;
787 arg->claim();
788 break;
789 case OPT_allow_shlib_undefined:
790 diagShlib = false;
791 break;
792 case OPT_no_allow_shlib_undefined:
793 diagShlib = true;
794 break;
795 }
796 }
797
798 ctx.arg.unresolvedSymbols =
799 diagRegular ? errorOrWarn : UnresolvedPolicy::Ignore;
800 ctx.arg.unresolvedSymbolsInShlib =
801 diagShlib ? errorOrWarn : UnresolvedPolicy::Ignore;
802}
803
804static Target2Policy getTarget2(Ctx &ctx, opt::InputArgList &args) {
805 StringRef s = args.getLastArgValue(Id: OPT_target2, Default: "got-rel");
806 if (s == "rel")
807 return Target2Policy::Rel;
808 if (s == "abs")
809 return Target2Policy::Abs;
810 if (s == "got-rel")
811 return Target2Policy::GotRel;
812 ErrAlways(ctx) << "unknown --target2 option: " << s;
813 return Target2Policy::GotRel;
814}
815
816static bool isOutputFormatBinary(Ctx &ctx, opt::InputArgList &args) {
817 StringRef s = args.getLastArgValue(Id: OPT_oformat, Default: "elf");
818 if (s == "binary")
819 return true;
820 if (!s.starts_with(Prefix: "elf"))
821 ErrAlways(ctx) << "unknown --oformat value: " << s;
822 return false;
823}
824
825static DiscardPolicy getDiscard(opt::InputArgList &args) {
826 auto *arg =
827 args.getLastArg(Ids: OPT_discard_all, Ids: OPT_discard_locals, Ids: OPT_discard_none);
828 if (!arg)
829 return DiscardPolicy::Default;
830 if (arg->getOption().getID() == OPT_discard_all)
831 return DiscardPolicy::All;
832 if (arg->getOption().getID() == OPT_discard_locals)
833 return DiscardPolicy::Locals;
834 return DiscardPolicy::None;
835}
836
837static StringRef getDynamicLinker(Ctx &ctx, opt::InputArgList &args) {
838 auto *arg = args.getLastArg(Ids: OPT_dynamic_linker, Ids: OPT_no_dynamic_linker);
839 if (!arg)
840 return "";
841 if (arg->getOption().getID() == OPT_no_dynamic_linker)
842 return "";
843 return arg->getValue();
844}
845
846static int getMemtagMode(Ctx &ctx, opt::InputArgList &args) {
847 StringRef memtagModeArg = args.getLastArgValue(Id: OPT_android_memtag_mode);
848 if (memtagModeArg.empty()) {
849 if (ctx.arg.androidMemtagStack)
850 Warn(ctx) << "--android-memtag-mode is unspecified, leaving "
851 "--android-memtag-stack a no-op";
852 else if (ctx.arg.androidMemtagHeap)
853 Warn(ctx) << "--android-memtag-mode is unspecified, leaving "
854 "--android-memtag-heap a no-op";
855 return ELF::NT_MEMTAG_LEVEL_NONE;
856 }
857
858 if (memtagModeArg == "sync")
859 return ELF::NT_MEMTAG_LEVEL_SYNC;
860 if (memtagModeArg == "async")
861 return ELF::NT_MEMTAG_LEVEL_ASYNC;
862 if (memtagModeArg == "none")
863 return ELF::NT_MEMTAG_LEVEL_NONE;
864
865 ErrAlways(ctx) << "unknown --android-memtag-mode value: \"" << memtagModeArg
866 << "\", should be one of {async, sync, none}";
867 return ELF::NT_MEMTAG_LEVEL_NONE;
868}
869
870static ICFLevel getICF(opt::InputArgList &args) {
871 auto *arg = args.getLastArg(Ids: OPT_icf_none, Ids: OPT_icf_safe, Ids: OPT_icf_all);
872 if (!arg || arg->getOption().getID() == OPT_icf_none)
873 return ICFLevel::None;
874 if (arg->getOption().getID() == OPT_icf_safe)
875 return ICFLevel::Safe;
876 return ICFLevel::All;
877}
878
879static void parsePackageMetadata(Ctx &ctx, const opt::Arg &arg) {
880 unsigned c0, c1;
881 SmallVector<uint8_t, 0> decoded;
882 StringRef s = arg.getValue();
883 for (size_t i = 0, e = s.size(); i != e; ++i) {
884 if (s[i] != '%') {
885 decoded.push_back(Elt: s[i]);
886 } else if (i + 2 < e && (c1 = hexDigitValue(C: s[i + 1])) != -1u &&
887 (c0 = hexDigitValue(C: s[i + 2])) != -1u) {
888 decoded.push_back(Elt: uint8_t(c1 * 16 + c0));
889 i += 2;
890 } else {
891 ErrAlways(ctx) << arg.getSpelling() << ": invalid % escape at byte " << i
892 << "; supports only %[0-9a-fA-F][0-9a-fA-F]";
893 return;
894 }
895 }
896 ctx.arg.packageMetadata = std::move(decoded);
897}
898
899static StripPolicy getStrip(Ctx &ctx, opt::InputArgList &args) {
900 if (args.hasArg(Ids: OPT_relocatable))
901 return StripPolicy::None;
902 if (!ctx.arg.zSectionHeader)
903 return StripPolicy::All;
904
905 auto *arg = args.getLastArg(Ids: OPT_strip_all, Ids: OPT_strip_debug);
906 if (!arg)
907 return StripPolicy::None;
908 if (arg->getOption().getID() == OPT_strip_all)
909 return StripPolicy::All;
910 return StripPolicy::Debug;
911}
912
913static uint64_t parseSectionAddress(Ctx &ctx, StringRef s,
914 opt::InputArgList &args,
915 const opt::Arg &arg) {
916 uint64_t va = 0;
917 s.consume_front(Prefix: "0x");
918 if (!to_integer(S: s, Num&: va, Base: 16))
919 ErrAlways(ctx) << "invalid argument: " << arg.getAsString(Args: args);
920 return va;
921}
922
923static StringMap<uint64_t> getSectionStartMap(Ctx &ctx,
924 opt::InputArgList &args) {
925 StringMap<uint64_t> ret;
926 for (auto *arg : args.filtered(Ids: OPT_section_start)) {
927 StringRef name;
928 StringRef addr;
929 std::tie(args&: name, args&: addr) = StringRef(arg->getValue()).split(Separator: '=');
930 ret[name] = parseSectionAddress(ctx, s: addr, args, arg: *arg);
931 }
932
933 if (auto *arg = args.getLastArg(Ids: OPT_Ttext))
934 ret[".text"] = parseSectionAddress(ctx, s: arg->getValue(), args, arg: *arg);
935 if (auto *arg = args.getLastArg(Ids: OPT_Tdata))
936 ret[".data"] = parseSectionAddress(ctx, s: arg->getValue(), args, arg: *arg);
937 if (auto *arg = args.getLastArg(Ids: OPT_Tbss))
938 ret[".bss"] = parseSectionAddress(ctx, s: arg->getValue(), args, arg: *arg);
939 return ret;
940}
941
942static SortSectionPolicy getSortSection(Ctx &ctx, opt::InputArgList &args) {
943 StringRef s = args.getLastArgValue(Id: OPT_sort_section);
944 if (s == "alignment")
945 return SortSectionPolicy::Alignment;
946 if (s == "name")
947 return SortSectionPolicy::Name;
948 if (!s.empty())
949 ErrAlways(ctx) << "unknown --sort-section rule: " << s;
950 return SortSectionPolicy::Default;
951}
952
953static OrphanHandlingPolicy getOrphanHandling(Ctx &ctx,
954 opt::InputArgList &args) {
955 StringRef s = args.getLastArgValue(Id: OPT_orphan_handling, Default: "place");
956 if (s == "warn")
957 return OrphanHandlingPolicy::Warn;
958 if (s == "error")
959 return OrphanHandlingPolicy::Error;
960 if (s != "place")
961 ErrAlways(ctx) << "unknown --orphan-handling mode: " << s;
962 return OrphanHandlingPolicy::Place;
963}
964
965// Parse --build-id or --build-id=<style>. We handle "tree" as a
966// synonym for "sha1" because all our hash functions including
967// --build-id=sha1 are actually tree hashes for performance reasons.
968static std::pair<BuildIdKind, SmallVector<uint8_t, 0>>
969getBuildId(Ctx &ctx, opt::InputArgList &args) {
970 auto *arg = args.getLastArg(Ids: OPT_build_id);
971 if (!arg)
972 return {BuildIdKind::None, {}};
973
974 StringRef s = arg->getValue();
975 if (s == "fast")
976 return {BuildIdKind::Fast, {}};
977 if (s == "md5")
978 return {BuildIdKind::Md5, {}};
979 if (s == "sha1" || s == "tree")
980 return {BuildIdKind::Sha1, {}};
981 if (s == "uuid")
982 return {BuildIdKind::Uuid, {}};
983 if (s.starts_with(Prefix: "0x"))
984 return {BuildIdKind::Hexstring, parseHex(s: s.substr(Start: 2))};
985
986 if (s != "none")
987 ErrAlways(ctx) << "unknown --build-id style: " << s;
988 return {BuildIdKind::None, {}};
989}
990
991static std::pair<bool, bool> getPackDynRelocs(Ctx &ctx,
992 opt::InputArgList &args) {
993 StringRef s = args.getLastArgValue(Id: OPT_pack_dyn_relocs, Default: "none");
994 if (s == "android")
995 return {true, false};
996 if (s == "relr")
997 return {false, true};
998 if (s == "android+relr")
999 return {true, true};
1000
1001 if (s != "none")
1002 ErrAlways(ctx) << "unknown --pack-dyn-relocs format: " << s;
1003 return {false, false};
1004}
1005
1006static void readCallGraph(Ctx &ctx, MemoryBufferRef mb) {
1007 // Build a map from symbol name to section
1008 DenseMap<StringRef, Symbol *> map;
1009 for (ELFFileBase *file : ctx.objectFiles)
1010 for (Symbol *sym : file->getSymbols())
1011 map[sym->getName()] = sym;
1012
1013 auto findSection = [&](StringRef name) -> InputSectionBase * {
1014 Symbol *sym = map.lookup(Val: name);
1015 if (!sym) {
1016 if (ctx.arg.warnSymbolOrdering)
1017 Warn(ctx) << mb.getBufferIdentifier() << ": no such symbol: " << name;
1018 return nullptr;
1019 }
1020 maybeWarnUnorderableSymbol(ctx, sym);
1021
1022 if (Defined *dr = dyn_cast_or_null<Defined>(Val: sym))
1023 return dyn_cast_or_null<InputSectionBase>(Val: dr->section);
1024 return nullptr;
1025 };
1026
1027 for (StringRef line : args::getLines(mb)) {
1028 SmallVector<StringRef, 3> fields;
1029 line.split(A&: fields, Separator: ' ');
1030 uint64_t count;
1031
1032 if (fields.size() != 3 || !to_integer(S: fields[2], Num&: count)) {
1033 ErrAlways(ctx) << mb.getBufferIdentifier() << ": parse error";
1034 return;
1035 }
1036
1037 if (InputSectionBase *from = findSection(fields[0]))
1038 if (InputSectionBase *to = findSection(fields[1]))
1039 ctx.arg.callGraphProfile[std::make_pair(x&: from, y&: to)] += count;
1040 }
1041}
1042
1043// If SHT_LLVM_CALL_GRAPH_PROFILE and its relocation section exist, returns
1044// true and populates cgProfile and symbolIndices.
1045template <class ELFT>
1046static bool
1047processCallGraphRelocations(Ctx &ctx, SmallVector<uint32_t, 32> &symbolIndices,
1048 ArrayRef<typename ELFT::CGProfile> &cgProfile,
1049 ObjFile<ELFT> *inputObj) {
1050 if (inputObj->cgProfileSectionIndex == SHN_UNDEF)
1051 return false;
1052
1053 ArrayRef<Elf_Shdr_Impl<ELFT>> objSections =
1054 inputObj->template getELFShdrs<ELFT>();
1055 symbolIndices.clear();
1056 const ELFFile<ELFT> &obj = inputObj->getObj();
1057 cgProfile =
1058 check(obj.template getSectionContentsAsArray<typename ELFT::CGProfile>(
1059 objSections[inputObj->cgProfileSectionIndex]));
1060
1061 for (size_t i = 0, e = objSections.size(); i < e; ++i) {
1062 const Elf_Shdr_Impl<ELFT> &sec = objSections[i];
1063 if (sec.sh_info == inputObj->cgProfileSectionIndex) {
1064 if (sec.sh_type == SHT_CREL) {
1065 auto crels =
1066 CHECK(obj.crels(sec), "could not retrieve cg profile rela section");
1067 for (const auto &rel : crels.first)
1068 symbolIndices.push_back(Elt: rel.getSymbol(false));
1069 for (const auto &rel : crels.second)
1070 symbolIndices.push_back(Elt: rel.getSymbol(false));
1071 break;
1072 }
1073 if (sec.sh_type == SHT_RELA) {
1074 ArrayRef<typename ELFT::Rela> relas =
1075 CHECK(obj.relas(sec), "could not retrieve cg profile rela section");
1076 for (const typename ELFT::Rela &rel : relas)
1077 symbolIndices.push_back(Elt: rel.getSymbol(ctx.arg.isMips64EL));
1078 break;
1079 }
1080 if (sec.sh_type == SHT_REL) {
1081 ArrayRef<typename ELFT::Rel> rels =
1082 CHECK(obj.rels(sec), "could not retrieve cg profile rel section");
1083 for (const typename ELFT::Rel &rel : rels)
1084 symbolIndices.push_back(Elt: rel.getSymbol(ctx.arg.isMips64EL));
1085 break;
1086 }
1087 }
1088 }
1089 if (symbolIndices.empty())
1090 Warn(ctx)
1091 << "SHT_LLVM_CALL_GRAPH_PROFILE exists, but relocation section doesn't";
1092 return !symbolIndices.empty();
1093}
1094
1095template <class ELFT> static void readCallGraphsFromObjectFiles(Ctx &ctx) {
1096 SmallVector<uint32_t, 32> symbolIndices;
1097 ArrayRef<typename ELFT::CGProfile> cgProfile;
1098 for (auto file : ctx.objectFiles) {
1099 auto *obj = cast<ObjFile<ELFT>>(file);
1100 if (!processCallGraphRelocations(ctx, symbolIndices, cgProfile, obj))
1101 continue;
1102
1103 if (symbolIndices.size() != cgProfile.size() * 2)
1104 Fatal(ctx) << "number of relocations doesn't match Weights";
1105
1106 for (uint32_t i = 0, size = cgProfile.size(); i < size; ++i) {
1107 const Elf_CGProfile_Impl<ELFT> &cgpe = cgProfile[i];
1108 uint32_t fromIndex = symbolIndices[i * 2];
1109 uint32_t toIndex = symbolIndices[i * 2 + 1];
1110 auto *fromSym = dyn_cast<Defined>(&obj->getSymbol(fromIndex));
1111 auto *toSym = dyn_cast<Defined>(&obj->getSymbol(toIndex));
1112 if (!fromSym || !toSym)
1113 continue;
1114
1115 auto *from = dyn_cast_or_null<InputSectionBase>(fromSym->section);
1116 auto *to = dyn_cast_or_null<InputSectionBase>(toSym->section);
1117 if (from && to)
1118 ctx.arg.callGraphProfile[{from, to}] += cgpe.cgp_weight;
1119 }
1120 }
1121}
1122
1123template <class ELFT>
1124static void ltoValidateAllVtablesHaveTypeInfos(Ctx &ctx,
1125 opt::InputArgList &args) {
1126 DenseSet<StringRef> typeInfoSymbols;
1127 SmallSetVector<StringRef, 0> vtableSymbols;
1128 auto processVtableAndTypeInfoSymbols = [&](StringRef name) {
1129 if (name.consume_front(Prefix: "_ZTI"))
1130 typeInfoSymbols.insert(V: name);
1131 else if (name.consume_front(Prefix: "_ZTV"))
1132 vtableSymbols.insert(X: name);
1133 };
1134
1135 // Examine all native symbol tables.
1136 for (ELFFileBase *f : ctx.objectFiles) {
1137 using Elf_Sym = typename ELFT::Sym;
1138 for (const Elf_Sym &s : f->template getGlobalELFSyms<ELFT>()) {
1139 if (s.st_shndx != SHN_UNDEF) {
1140 StringRef name = check(s.getName(f->getStringTable()));
1141 processVtableAndTypeInfoSymbols(name);
1142 }
1143 }
1144 }
1145
1146 for (SharedFile *f : ctx.sharedFiles) {
1147 using Elf_Sym = typename ELFT::Sym;
1148 for (const Elf_Sym &s : f->template getELFSyms<ELFT>()) {
1149 if (s.st_shndx != SHN_UNDEF) {
1150 StringRef name = check(s.getName(f->getStringTable()));
1151 processVtableAndTypeInfoSymbols(name);
1152 }
1153 }
1154 }
1155
1156 SmallSetVector<StringRef, 0> vtableSymbolsWithNoRTTI;
1157 for (StringRef s : vtableSymbols)
1158 if (!typeInfoSymbols.count(V: s))
1159 vtableSymbolsWithNoRTTI.insert(X: s);
1160
1161 // Remove known safe symbols.
1162 for (auto *arg : args.filtered(Ids: OPT_lto_known_safe_vtables)) {
1163 StringRef knownSafeName = arg->getValue();
1164 if (!knownSafeName.consume_front(Prefix: "_ZTV"))
1165 ErrAlways(ctx)
1166 << "--lto-known-safe-vtables=: expected symbol to start with _ZTV, "
1167 "but got "
1168 << knownSafeName;
1169 Expected<GlobPattern> pat = GlobPattern::create(Pat: knownSafeName);
1170 if (!pat)
1171 ErrAlways(ctx) << "--lto-known-safe-vtables=: " << pat.takeError();
1172 vtableSymbolsWithNoRTTI.remove_if(
1173 [&](StringRef s) { return pat->match(S: s); });
1174 }
1175
1176 ctx.ltoAllVtablesHaveTypeInfos = vtableSymbolsWithNoRTTI.empty();
1177 // Check for unmatched RTTI symbols
1178 for (StringRef s : vtableSymbolsWithNoRTTI) {
1179 Msg(ctx) << "--lto-validate-all-vtables-have-type-infos: RTTI missing for "
1180 "vtable "
1181 "_ZTV"
1182 << s << ", --lto-whole-program-visibility disabled";
1183 }
1184}
1185
1186static CGProfileSortKind getCGProfileSortKind(Ctx &ctx,
1187 opt::InputArgList &args) {
1188 StringRef s = args.getLastArgValue(Id: OPT_call_graph_profile_sort, Default: "cdsort");
1189 if (s == "hfsort")
1190 return CGProfileSortKind::Hfsort;
1191 if (s == "cdsort")
1192 return CGProfileSortKind::Cdsort;
1193 if (s != "none")
1194 ErrAlways(ctx) << "unknown --call-graph-profile-sort= value: " << s;
1195 return CGProfileSortKind::None;
1196}
1197
1198static void parseBPOrdererOptions(Ctx &ctx, opt::InputArgList &args) {
1199 if (auto *arg = args.getLastArg(Ids: OPT_bp_compression_sort)) {
1200 StringRef s = arg->getValue();
1201 if (s == "function") {
1202 ctx.arg.bpFunctionOrderForCompression = true;
1203 } else if (s == "data") {
1204 ctx.arg.bpDataOrderForCompression = true;
1205 } else if (s == "both") {
1206 ctx.arg.bpFunctionOrderForCompression = true;
1207 ctx.arg.bpDataOrderForCompression = true;
1208 } else if (s != "none") {
1209 ErrAlways(ctx) << arg->getSpelling()
1210 << ": expected [none|function|data|both]";
1211 }
1212 if (s != "none" && args.hasArg(Ids: OPT_call_graph_ordering_file))
1213 ErrAlways(ctx) << "--bp-compression-sort is incompatible with "
1214 "--call-graph-ordering-file";
1215 }
1216 if (auto *arg = args.getLastArg(Ids: OPT_bp_startup_sort)) {
1217 StringRef s = arg->getValue();
1218 if (s == "function") {
1219 ctx.arg.bpStartupFunctionSort = true;
1220 } else if (s != "none") {
1221 ErrAlways(ctx) << arg->getSpelling() << ": expected [none|function]";
1222 }
1223 if (s != "none" && args.hasArg(Ids: OPT_call_graph_ordering_file))
1224 ErrAlways(ctx) << "--bp-startup-sort=function is incompatible with "
1225 "--call-graph-ordering-file";
1226 }
1227
1228 ctx.arg.bpCompressionSortStartupFunctions =
1229 args.hasFlag(Pos: OPT_bp_compression_sort_startup_functions,
1230 Neg: OPT_no_bp_compression_sort_startup_functions, Default: false);
1231 ctx.arg.bpVerboseSectionOrderer = args.hasArg(Ids: OPT_verbose_bp_section_orderer);
1232
1233 ctx.arg.irpgoProfilePath = args.getLastArgValue(Id: OPT_irpgo_profile);
1234 if (ctx.arg.irpgoProfilePath.empty()) {
1235 if (ctx.arg.bpStartupFunctionSort)
1236 ErrAlways(ctx) << "--bp-startup-sort=function must be used with "
1237 "--irpgo-profile";
1238 if (ctx.arg.bpCompressionSortStartupFunctions)
1239 ErrAlways(ctx)
1240 << "--bp-compression-sort-startup-functions must be used with "
1241 "--irpgo-profile";
1242 }
1243}
1244
1245static DebugCompressionType getCompressionType(Ctx &ctx, StringRef s,
1246 StringRef option) {
1247 DebugCompressionType type = StringSwitch<DebugCompressionType>(s)
1248 .Case(S: "zlib", Value: DebugCompressionType::Zlib)
1249 .Case(S: "zstd", Value: DebugCompressionType::Zstd)
1250 .Default(Value: DebugCompressionType::None);
1251 if (type == DebugCompressionType::None) {
1252 if (s != "none")
1253 ErrAlways(ctx) << "unknown " << option << " value: " << s;
1254 } else if (const char *reason = compression::getReasonIfUnsupported(
1255 F: compression::formatFor(Type: type))) {
1256 ErrAlways(ctx) << option << ": " << reason;
1257 }
1258 return type;
1259}
1260
1261static StringRef getAliasSpelling(opt::Arg *arg) {
1262 if (const opt::Arg *alias = arg->getAlias())
1263 return alias->getSpelling();
1264 return arg->getSpelling();
1265}
1266
1267static std::pair<StringRef, StringRef>
1268getOldNewOptions(Ctx &ctx, opt::InputArgList &args, unsigned id) {
1269 auto *arg = args.getLastArg(Ids: id);
1270 if (!arg)
1271 return {"", ""};
1272
1273 StringRef s = arg->getValue();
1274 std::pair<StringRef, StringRef> ret = s.split(Separator: ';');
1275 if (ret.second.empty())
1276 ErrAlways(ctx) << getAliasSpelling(arg)
1277 << " expects 'old;new' format, but got " << s;
1278 return ret;
1279}
1280
1281// Parse options of the form "old;new[;extra]".
1282static std::tuple<StringRef, StringRef, StringRef>
1283getOldNewOptionsExtra(Ctx &ctx, opt::InputArgList &args, unsigned id) {
1284 auto [oldDir, second] = getOldNewOptions(ctx, args, id);
1285 auto [newDir, extraDir] = second.split(Separator: ';');
1286 return {oldDir, newDir, extraDir};
1287}
1288
1289// Parse the symbol ordering file and warn for any duplicate entries.
1290static SmallVector<StringRef, 0> getSymbolOrderingFile(Ctx &ctx,
1291 MemoryBufferRef mb) {
1292 SetVector<StringRef, SmallVector<StringRef, 0>> names;
1293 for (StringRef s : args::getLines(mb))
1294 if (!names.insert(X: s) && ctx.arg.warnSymbolOrdering)
1295 Warn(ctx) << mb.getBufferIdentifier()
1296 << ": duplicate ordered symbol: " << s;
1297
1298 return names.takeVector();
1299}
1300
1301static bool getIsRela(Ctx &ctx, opt::InputArgList &args) {
1302 // The psABI specifies the default relocation entry format.
1303 bool rela = is_contained(Set: {EM_AARCH64, EM_AMDGPU, EM_HEXAGON, EM_LOONGARCH,
1304 EM_PPC, EM_PPC64, EM_RISCV, EM_S390, EM_X86_64},
1305 Element: ctx.arg.emachine);
1306 // If -z rel or -z rela is specified, use the last option.
1307 for (auto *arg : args.filtered(Ids: OPT_z)) {
1308 StringRef s(arg->getValue());
1309 if (s == "rel")
1310 rela = false;
1311 else if (s == "rela")
1312 rela = true;
1313 else
1314 continue;
1315 arg->claim();
1316 }
1317 return rela;
1318}
1319
1320static void parseClangOption(Ctx &ctx, StringRef opt, const Twine &msg) {
1321 std::string err;
1322 raw_string_ostream os(err);
1323
1324 const char *argv[] = {ctx.arg.progName.data(), opt.data()};
1325 if (cl::ParseCommandLineOptions(argc: 2, argv, Overview: "", Errs: &os))
1326 return;
1327 ErrAlways(ctx) << msg << ": " << StringRef(err).trim();
1328}
1329
1330// Process a remap pattern 'from-glob=to-file'.
1331static bool remapInputs(Ctx &ctx, StringRef line, const Twine &location) {
1332 SmallVector<StringRef, 0> fields;
1333 line.split(A&: fields, Separator: '=');
1334 if (fields.size() != 2 || fields[1].empty()) {
1335 ErrAlways(ctx) << location << ": parse error, not 'from-glob=to-file'";
1336 return true;
1337 }
1338 if (!hasWildcard(s: fields[0]))
1339 ctx.arg.remapInputs[fields[0]] = fields[1];
1340 else if (Expected<GlobPattern> pat = GlobPattern::create(Pat: fields[0]))
1341 ctx.arg.remapInputsWildcards.emplace_back(Args: std::move(*pat), Args&: fields[1]);
1342 else {
1343 ErrAlways(ctx) << location << ": " << pat.takeError() << ": " << fields[0];
1344 return true;
1345 }
1346 return false;
1347}
1348
1349// Initializes Config members by the command line options.
1350static void readConfigs(Ctx &ctx, opt::InputArgList &args) {
1351 ctx.e.verbose = args.hasArg(Ids: OPT_verbose);
1352 ctx.e.vsDiagnostics =
1353 args.hasArg(Ids: OPT_visual_studio_diagnostics_format, Ids: false);
1354
1355 ctx.arg.allowMultipleDefinition =
1356 hasZOption(args, key: "muldefs") ||
1357 args.hasFlag(Pos: OPT_allow_multiple_definition,
1358 Neg: OPT_no_allow_multiple_definition, Default: false);
1359 ctx.arg.androidMemtagHeap =
1360 args.hasFlag(Pos: OPT_android_memtag_heap, Neg: OPT_no_android_memtag_heap, Default: false);
1361 ctx.arg.androidMemtagStack = args.hasFlag(Pos: OPT_android_memtag_stack,
1362 Neg: OPT_no_android_memtag_stack, Default: false);
1363 ctx.arg.fatLTOObjects =
1364 args.hasFlag(Pos: OPT_fat_lto_objects, Neg: OPT_no_fat_lto_objects, Default: false);
1365 ctx.arg.androidMemtagMode = getMemtagMode(ctx, args);
1366 ctx.arg.auxiliaryList = args::getStrings(args, id: OPT_auxiliary);
1367 ctx.arg.armBe8 = args.hasArg(Ids: OPT_be8);
1368 if (opt::Arg *arg = args.getLastArg(
1369 Ids: OPT_Bno_symbolic, Ids: OPT_Bsymbolic_non_weak_functions,
1370 Ids: OPT_Bsymbolic_functions, Ids: OPT_Bsymbolic_non_weak, Ids: OPT_Bsymbolic)) {
1371 if (arg->getOption().matches(ID: OPT_Bsymbolic_non_weak_functions))
1372 ctx.arg.bsymbolic = BsymbolicKind::NonWeakFunctions;
1373 else if (arg->getOption().matches(ID: OPT_Bsymbolic_functions))
1374 ctx.arg.bsymbolic = BsymbolicKind::Functions;
1375 else if (arg->getOption().matches(ID: OPT_Bsymbolic_non_weak))
1376 ctx.arg.bsymbolic = BsymbolicKind::NonWeak;
1377 else if (arg->getOption().matches(ID: OPT_Bsymbolic))
1378 ctx.arg.bsymbolic = BsymbolicKind::All;
1379 }
1380 ctx.arg.callGraphProfileSort = getCGProfileSortKind(ctx, args);
1381 parseBPOrdererOptions(ctx, args);
1382 ctx.arg.checkSections =
1383 args.hasFlag(Pos: OPT_check_sections, Neg: OPT_no_check_sections, Default: true);
1384 ctx.arg.chroot = args.getLastArgValue(Id: OPT_chroot);
1385 if (auto *arg = args.getLastArg(Ids: OPT_compress_debug_sections)) {
1386 ctx.arg.compressDebugSections =
1387 getCompressionType(ctx, s: arg->getValue(), option: "--compress-debug-sections");
1388 }
1389 ctx.arg.cref = args.hasArg(Ids: OPT_cref);
1390 ctx.arg.optimizeBBJumps =
1391 args.hasFlag(Pos: OPT_optimize_bb_jumps, Neg: OPT_no_optimize_bb_jumps, Default: false);
1392 ctx.arg.debugNames = args.hasFlag(Pos: OPT_debug_names, Neg: OPT_no_debug_names, Default: false);
1393 ctx.arg.demangle = args.hasFlag(Pos: OPT_demangle, Neg: OPT_no_demangle, Default: true);
1394 ctx.arg.dependencyFile = args.getLastArgValue(Id: OPT_dependency_file);
1395 ctx.arg.dependentLibraries =
1396 args.hasFlag(Pos: OPT_dependent_libraries, Neg: OPT_no_dependent_libraries, Default: true);
1397 ctx.arg.disableVerify = args.hasArg(Ids: OPT_disable_verify);
1398 ctx.arg.discard = getDiscard(args);
1399 ctx.arg.dtltoDistributor = args.getLastArgValue(Id: OPT_thinlto_distributor_eq);
1400 ctx.arg.dtltoDistributorArgs =
1401 args::getStrings(args, id: OPT_thinlto_distributor_arg);
1402 ctx.arg.dtltoCompiler = args.getLastArgValue(Id: OPT_thinlto_compiler_eq);
1403 ctx.arg.dtltoCompilerArgs = args::getStrings(args, id: OPT_thinlto_compiler_arg);
1404 ctx.arg.dwoDir = args.getLastArgValue(Id: OPT_plugin_opt_dwo_dir_eq);
1405 ctx.arg.dynamicLinker = getDynamicLinker(ctx, args);
1406 ctx.arg.ehFrameHdr =
1407 args.hasFlag(Pos: OPT_eh_frame_hdr, Neg: OPT_no_eh_frame_hdr, Default: false);
1408 ctx.arg.emitLLVM = args.hasArg(Ids: OPT_lto_emit_llvm);
1409 ctx.arg.emitRelocs = args.hasArg(Ids: OPT_emit_relocs);
1410 ctx.arg.enableNewDtags =
1411 args.hasFlag(Pos: OPT_enable_new_dtags, Neg: OPT_disable_new_dtags, Default: true);
1412 ctx.arg.enableNonContiguousRegions =
1413 args.hasArg(Ids: OPT_enable_non_contiguous_regions);
1414 ctx.arg.entry = args.getLastArgValue(Id: OPT_entry);
1415
1416 ctx.e.errorHandlingScript = args.getLastArgValue(Id: OPT_error_handling_script);
1417
1418 ctx.arg.executeOnly =
1419 args.hasFlag(Pos: OPT_execute_only, Neg: OPT_no_execute_only, Default: false);
1420 ctx.arg.exportDynamic =
1421 args.hasFlag(Pos: OPT_export_dynamic, Neg: OPT_no_export_dynamic, Default: false) ||
1422 args.hasArg(Ids: OPT_shared);
1423 ctx.arg.filterList = args::getStrings(args, id: OPT_filter);
1424 ctx.arg.fini = args.getLastArgValue(Id: OPT_fini, Default: "_fini");
1425 ctx.arg.fixCortexA53Errata843419 =
1426 args.hasArg(Ids: OPT_fix_cortex_a53_843419) && !args.hasArg(Ids: OPT_relocatable);
1427 ctx.arg.cmseImplib = args.hasArg(Ids: OPT_cmse_implib);
1428 ctx.arg.cmseInputLib = args.getLastArgValue(Id: OPT_in_implib);
1429 ctx.arg.cmseOutputLib = args.getLastArgValue(Id: OPT_out_implib);
1430 ctx.arg.fixCortexA8 =
1431 args.hasArg(Ids: OPT_fix_cortex_a8) && !args.hasArg(Ids: OPT_relocatable);
1432 ctx.arg.fortranCommon =
1433 args.hasFlag(Pos: OPT_fortran_common, Neg: OPT_no_fortran_common, Default: false);
1434 ctx.arg.gcSections = args.hasFlag(Pos: OPT_gc_sections, Neg: OPT_no_gc_sections, Default: false);
1435 ctx.arg.gnuUnique = args.hasFlag(Pos: OPT_gnu_unique, Neg: OPT_no_gnu_unique, Default: true);
1436 ctx.arg.gdbIndex = args.hasFlag(Pos: OPT_gdb_index, Neg: OPT_no_gdb_index, Default: false);
1437 ctx.arg.icf = getICF(args);
1438 ctx.arg.ignoreDataAddressEquality =
1439 args.hasArg(Ids: OPT_ignore_data_address_equality);
1440 ctx.arg.ignoreFunctionAddressEquality =
1441 args.hasArg(Ids: OPT_ignore_function_address_equality);
1442 ctx.arg.init = args.getLastArgValue(Id: OPT_init, Default: "_init");
1443 ctx.arg.ltoAAPipeline = args.getLastArgValue(Id: OPT_lto_aa_pipeline);
1444 ctx.arg.ltoCSProfileGenerate = args.hasArg(Ids: OPT_lto_cs_profile_generate);
1445 ctx.arg.ltoCSProfileFile = args.getLastArgValue(Id: OPT_lto_cs_profile_file);
1446 ctx.arg.ltoPGOWarnMismatch = args.hasFlag(Pos: OPT_lto_pgo_warn_mismatch,
1447 Neg: OPT_no_lto_pgo_warn_mismatch, Default: true);
1448 ctx.arg.ltoDebugPassManager = args.hasArg(Ids: OPT_lto_debug_pass_manager);
1449 ctx.arg.ltoEmitAsm = args.hasArg(Ids: OPT_lto_emit_asm);
1450 ctx.arg.ltoNewPmPasses = args.getLastArgValue(Id: OPT_lto_newpm_passes);
1451 ctx.arg.ltoWholeProgramVisibility =
1452 args.hasFlag(Pos: OPT_lto_whole_program_visibility,
1453 Neg: OPT_no_lto_whole_program_visibility, Default: false);
1454 ctx.arg.ltoValidateAllVtablesHaveTypeInfos =
1455 args.hasFlag(Pos: OPT_lto_validate_all_vtables_have_type_infos,
1456 Neg: OPT_no_lto_validate_all_vtables_have_type_infos, Default: false);
1457 ctx.arg.ltoo = args::getInteger(args, key: OPT_lto_O, Default: 2);
1458 if (ctx.arg.ltoo > 3)
1459 ErrAlways(ctx) << "invalid optimization level for LTO: " << ctx.arg.ltoo;
1460 unsigned ltoCgo =
1461 args::getInteger(args, key: OPT_lto_CGO, Default: args::getCGOptLevel(optLevelLTO: ctx.arg.ltoo));
1462 if (auto level = CodeGenOpt::getLevel(OL: ltoCgo))
1463 ctx.arg.ltoCgo = *level;
1464 else
1465 ErrAlways(ctx) << "invalid codegen optimization level for LTO: " << ltoCgo;
1466 ctx.arg.ltoObjPath = args.getLastArgValue(Id: OPT_lto_obj_path_eq);
1467 ctx.arg.ltoPartitions = args::getInteger(args, key: OPT_lto_partitions, Default: 1);
1468 ctx.arg.ltoSampleProfile = args.getLastArgValue(Id: OPT_lto_sample_profile);
1469 ctx.arg.ltoBBAddrMap =
1470 args.hasFlag(Pos: OPT_lto_basic_block_address_map,
1471 Neg: OPT_no_lto_basic_block_address_map, Default: false);
1472 ctx.arg.ltoBasicBlockSections =
1473 args.getLastArgValue(Id: OPT_lto_basic_block_sections);
1474 ctx.arg.ltoUniqueBasicBlockSectionNames =
1475 args.hasFlag(Pos: OPT_lto_unique_basic_block_section_names,
1476 Neg: OPT_no_lto_unique_basic_block_section_names, Default: false);
1477 ctx.arg.mapFile = args.getLastArgValue(Id: OPT_Map);
1478 ctx.arg.mipsGotSize = args::getInteger(args, key: OPT_mips_got_size, Default: 0xfff0);
1479 ctx.arg.mergeArmExidx =
1480 args.hasFlag(Pos: OPT_merge_exidx_entries, Neg: OPT_no_merge_exidx_entries, Default: true);
1481 ctx.arg.mmapOutputFile =
1482 args.hasFlag(Pos: OPT_mmap_output_file, Neg: OPT_no_mmap_output_file, Default: false);
1483 ctx.arg.nmagic = args.hasFlag(Pos: OPT_nmagic, Neg: OPT_no_nmagic, Default: false);
1484 ctx.arg.noinhibitExec = args.hasArg(Ids: OPT_noinhibit_exec);
1485 ctx.arg.nostdlib = args.hasArg(Ids: OPT_nostdlib);
1486 ctx.arg.oFormatBinary = isOutputFormatBinary(ctx, args);
1487 ctx.arg.omagic = args.hasFlag(Pos: OPT_omagic, Neg: OPT_no_omagic, Default: false);
1488 ctx.arg.optRemarksFilename = args.getLastArgValue(Id: OPT_opt_remarks_filename);
1489 ctx.arg.optStatsFilename = args.getLastArgValue(Id: OPT_plugin_opt_stats_file);
1490
1491 // Parse remarks hotness threshold. Valid value is either integer or 'auto'.
1492 if (auto *arg = args.getLastArg(Ids: OPT_opt_remarks_hotness_threshold)) {
1493 auto resultOrErr = remarks::parseHotnessThresholdOption(Arg: arg->getValue());
1494 if (!resultOrErr)
1495 ErrAlways(ctx) << arg->getSpelling() << ": invalid argument '"
1496 << arg->getValue()
1497 << "', only integer or 'auto' is supported";
1498 else
1499 ctx.arg.optRemarksHotnessThreshold = *resultOrErr;
1500 }
1501
1502 ctx.arg.optRemarksPasses = args.getLastArgValue(Id: OPT_opt_remarks_passes);
1503 ctx.arg.optRemarksWithHotness = args.hasArg(Ids: OPT_opt_remarks_with_hotness);
1504 ctx.arg.optRemarksFormat = args.getLastArgValue(Id: OPT_opt_remarks_format);
1505 ctx.arg.optimize = args::getInteger(args, key: OPT_O, Default: 1);
1506 ctx.arg.orphanHandling = getOrphanHandling(ctx, args);
1507 ctx.arg.outputFile = args.getLastArgValue(Id: OPT_o);
1508 if (auto *arg = args.getLastArg(Ids: OPT_package_metadata))
1509 parsePackageMetadata(ctx, arg: *arg);
1510 ctx.arg.pie = args.hasFlag(Pos: OPT_pie, Neg: OPT_no_pie, Default: false);
1511 ctx.arg.printIcfSections =
1512 args.hasFlag(Pos: OPT_print_icf_sections, Neg: OPT_no_print_icf_sections, Default: false);
1513 ctx.arg.printGcSections =
1514 args.hasFlag(Pos: OPT_print_gc_sections, Neg: OPT_no_print_gc_sections, Default: false);
1515 ctx.arg.printMemoryUsage = args.hasArg(Ids: OPT_print_memory_usage);
1516 ctx.arg.printArchiveStats = args.getLastArgValue(Id: OPT_print_archive_stats);
1517 ctx.arg.printSymbolOrder = args.getLastArgValue(Id: OPT_print_symbol_order);
1518 ctx.arg.rejectMismatch = !args.hasArg(Ids: OPT_no_warn_mismatch);
1519 ctx.arg.relax = args.hasFlag(Pos: OPT_relax, Neg: OPT_no_relax, Default: true);
1520 ctx.arg.relaxGP = args.hasFlag(Pos: OPT_relax_gp, Neg: OPT_no_relax_gp, Default: false);
1521 ctx.arg.rpath = getRpath(args);
1522 ctx.arg.relocatable = args.hasArg(Ids: OPT_relocatable);
1523 ctx.arg.resolveGroups =
1524 !args.hasArg(Ids: OPT_relocatable) || args.hasArg(Ids: OPT_force_group_allocation);
1525
1526 if (args.hasArg(Ids: OPT_save_temps)) {
1527 // --save-temps implies saving all temps.
1528 ctx.arg.saveTempsArgs.insert_range(R: saveTempsValues);
1529 } else {
1530 for (auto *arg : args.filtered(Ids: OPT_save_temps_eq)) {
1531 StringRef s = arg->getValue();
1532 if (llvm::is_contained(Range: saveTempsValues, Element: s))
1533 ctx.arg.saveTempsArgs.insert(V: s);
1534 else
1535 ErrAlways(ctx) << "unknown --save-temps value: " << s;
1536 }
1537 }
1538
1539 ctx.arg.searchPaths = args::getStrings(args, id: OPT_library_path);
1540 ctx.arg.sectionStartMap = getSectionStartMap(ctx, args);
1541 ctx.arg.shared = args.hasArg(Ids: OPT_shared);
1542 if (args.hasArg(Ids: OPT_randomize_section_padding))
1543 ctx.arg.randomizeSectionPadding =
1544 args::getInteger(args, key: OPT_randomize_section_padding, Default: 0);
1545 ctx.arg.singleRoRx = !args.hasFlag(Pos: OPT_rosegment, Neg: OPT_no_rosegment, Default: true);
1546 ctx.arg.singleXoRx = !args.hasFlag(Pos: OPT_xosegment, Neg: OPT_no_xosegment, Default: false);
1547 ctx.arg.soName = args.getLastArgValue(Id: OPT_soname);
1548 ctx.arg.sortSection = getSortSection(ctx, args);
1549 ctx.arg.splitStackAdjustSize =
1550 args::getInteger(args, key: OPT_split_stack_adjust_size, Default: 16384);
1551 ctx.arg.zSectionHeader =
1552 getZFlag(args, k1: "sectionheader", k2: "nosectionheader", defaultValue: true);
1553 ctx.arg.strip = getStrip(ctx, args); // needs zSectionHeader
1554 ctx.arg.sysroot = args.getLastArgValue(Id: OPT_sysroot);
1555 ctx.arg.target1Rel = args.hasFlag(Pos: OPT_target1_rel, Neg: OPT_target1_abs, Default: false);
1556 ctx.arg.target2 = getTarget2(ctx, args);
1557 ctx.arg.thinLTOCacheDir = args.getLastArgValue(Id: OPT_thinlto_cache_dir);
1558 ctx.arg.thinLTOCachePolicy = CHECK(
1559 parseCachePruningPolicy(args.getLastArgValue(OPT_thinlto_cache_policy)),
1560 "--thinlto-cache-policy: invalid cache policy");
1561 ctx.arg.thinLTOEmitImportsFiles = args.hasArg(Ids: OPT_thinlto_emit_imports_files);
1562 ctx.arg.thinLTOEmitIndexFiles = args.hasArg(Ids: OPT_thinlto_emit_index_files) ||
1563 args.hasArg(Ids: OPT_thinlto_index_only) ||
1564 args.hasArg(Ids: OPT_thinlto_index_only_eq);
1565 ctx.arg.thinLTOIndexOnly = args.hasArg(Ids: OPT_thinlto_index_only) ||
1566 args.hasArg(Ids: OPT_thinlto_index_only_eq);
1567 ctx.arg.thinLTOIndexOnlyArg = args.getLastArgValue(Id: OPT_thinlto_index_only_eq);
1568 ctx.arg.thinLTOObjectSuffixReplace =
1569 getOldNewOptions(ctx, args, id: OPT_thinlto_object_suffix_replace_eq);
1570 std::tie(args&: ctx.arg.thinLTOPrefixReplaceOld, args&: ctx.arg.thinLTOPrefixReplaceNew,
1571 args&: ctx.arg.thinLTOPrefixReplaceNativeObject) =
1572 getOldNewOptionsExtra(ctx, args, id: OPT_thinlto_prefix_replace_eq);
1573 if (ctx.arg.thinLTOEmitIndexFiles && !ctx.arg.thinLTOIndexOnly) {
1574 if (args.hasArg(Ids: OPT_thinlto_object_suffix_replace_eq))
1575 ErrAlways(ctx) << "--thinlto-object-suffix-replace is not supported with "
1576 "--thinlto-emit-index-files";
1577 else if (args.hasArg(Ids: OPT_thinlto_prefix_replace_eq))
1578 ErrAlways(ctx) << "--thinlto-prefix-replace is not supported with "
1579 "--thinlto-emit-index-files";
1580 }
1581 if (!ctx.arg.thinLTOPrefixReplaceNativeObject.empty() &&
1582 ctx.arg.thinLTOIndexOnlyArg.empty()) {
1583 ErrAlways(ctx)
1584 << "--thinlto-prefix-replace=old_dir;new_dir;obj_dir must be used with "
1585 "--thinlto-index-only=";
1586 }
1587 ctx.arg.thinLTOModulesToCompile =
1588 args::getStrings(args, id: OPT_thinlto_single_module_eq);
1589 ctx.arg.timeTraceEnabled =
1590 args.hasArg(Ids: OPT_time_trace_eq) && !ctx.e.disableOutput;
1591 ctx.arg.timeTraceGranularity =
1592 args::getInteger(args, key: OPT_time_trace_granularity, Default: 500);
1593 ctx.arg.trace = args.hasArg(Ids: OPT_trace);
1594 ctx.arg.undefined = args::getStrings(args, id: OPT_undefined);
1595 ctx.arg.undefinedVersion =
1596 args.hasFlag(Pos: OPT_undefined_version, Neg: OPT_no_undefined_version, Default: false);
1597 ctx.arg.unique = args.hasArg(Ids: OPT_unique);
1598 ctx.arg.useAndroidRelrTags = args.hasFlag(
1599 Pos: OPT_use_android_relr_tags, Neg: OPT_no_use_android_relr_tags, Default: false);
1600 ctx.arg.warnBackrefs =
1601 args.hasFlag(Pos: OPT_warn_backrefs, Neg: OPT_no_warn_backrefs, Default: false);
1602 ctx.arg.warnCommon = args.hasFlag(Pos: OPT_warn_common, Neg: OPT_no_warn_common, Default: false);
1603 ctx.arg.warnSymbolOrdering =
1604 args.hasFlag(Pos: OPT_warn_symbol_ordering, Neg: OPT_no_warn_symbol_ordering, Default: true);
1605 ctx.arg.whyExtract = args.getLastArgValue(Id: OPT_why_extract);
1606 for (opt::Arg *arg : args.filtered(Ids: OPT_why_live)) {
1607 StringRef value(arg->getValue());
1608 if (Expected<GlobPattern> pat = GlobPattern::create(Pat: arg->getValue())) {
1609 ctx.arg.whyLive.emplace_back(Args: std::move(*pat));
1610 } else {
1611 ErrAlways(ctx) << arg->getSpelling() << ": " << pat.takeError();
1612 continue;
1613 }
1614 }
1615 ctx.arg.zCombreloc = getZFlag(args, k1: "combreloc", k2: "nocombreloc", defaultValue: true);
1616 ctx.arg.zCopyreloc = getZFlag(args, k1: "copyreloc", k2: "nocopyreloc", defaultValue: true);
1617 ctx.arg.zForceBti = hasZOption(args, key: "force-bti");
1618 ctx.arg.zForceIbt = hasZOption(args, key: "force-ibt");
1619 ctx.arg.zZicfilp = getZZicfilp(ctx, args);
1620 ctx.arg.zZicfiss = getZZicfiss(ctx, args);
1621 ctx.arg.zGcs = getZGcs(ctx, args);
1622 ctx.arg.zGlobal = hasZOption(args, key: "global");
1623 ctx.arg.zGnustack = getZGnuStack(args);
1624 ctx.arg.zHazardplt = hasZOption(args, key: "hazardplt");
1625 ctx.arg.zIfuncNoplt = hasZOption(args, key: "ifunc-noplt");
1626 ctx.arg.zInitfirst = hasZOption(args, key: "initfirst");
1627 ctx.arg.zInterpose = hasZOption(args, key: "interpose");
1628 ctx.arg.zKeepTextSectionPrefix = getZFlag(
1629 args, k1: "keep-text-section-prefix", k2: "nokeep-text-section-prefix", defaultValue: false);
1630 ctx.arg.zLrodataAfterBss =
1631 getZFlag(args, k1: "lrodata-after-bss", k2: "nolrodata-after-bss", defaultValue: false);
1632 ctx.arg.zNoBtCfi = hasZOption(args, key: "nobtcfi");
1633 ctx.arg.zNodefaultlib = hasZOption(args, key: "nodefaultlib");
1634 ctx.arg.zNodelete = hasZOption(args, key: "nodelete");
1635 ctx.arg.zNodlopen = hasZOption(args, key: "nodlopen");
1636 ctx.arg.zNow = getZFlag(args, k1: "now", k2: "lazy", defaultValue: false);
1637 ctx.arg.zOrigin = hasZOption(args, key: "origin");
1638 ctx.arg.zPacPlt = getZFlag(args, k1: "pac-plt", k2: "nopac-plt", defaultValue: false);
1639 ctx.arg.zRelro = getZFlag(args, k1: "relro", k2: "norelro", defaultValue: true);
1640 ctx.arg.zRetpolineplt = hasZOption(args, key: "retpolineplt");
1641 ctx.arg.zRodynamic = hasZOption(args, key: "rodynamic");
1642 ctx.arg.zSeparate = getZSeparate(args);
1643 ctx.arg.zShstk = hasZOption(args, key: "shstk");
1644 ctx.arg.zStackSize = args::getZOptionValue(args, id: OPT_z, key: "stack-size", Default: 0);
1645 ctx.arg.zStartStopGC =
1646 getZFlag(args, k1: "start-stop-gc", k2: "nostart-stop-gc", defaultValue: true);
1647 ctx.arg.zStartStopVisibility = getZStartStopVisibility(ctx, args);
1648 ctx.arg.zText = getZFlag(args, k1: "text", k2: "notext", defaultValue: true);
1649 ctx.arg.zWxneeded = hasZOption(args, key: "wxneeded");
1650 setUnresolvedSymbolPolicy(ctx, args);
1651 ctx.arg.power10Stubs = args.getLastArgValue(Id: OPT_power10_stubs_eq) != "no";
1652 ctx.arg.branchToBranch = args.hasFlag(
1653 Pos: OPT_branch_to_branch, Neg: OPT_no_branch_to_branch, Default: ctx.arg.optimize >= 2);
1654
1655 if (opt::Arg *arg = args.getLastArg(Ids: OPT_eb, Ids: OPT_el)) {
1656 if (arg->getOption().matches(ID: OPT_eb))
1657 ctx.arg.optEB = true;
1658 else
1659 ctx.arg.optEL = true;
1660 }
1661
1662 for (opt::Arg *arg : args.filtered(Ids: OPT_remap_inputs)) {
1663 StringRef value(arg->getValue());
1664 remapInputs(ctx, line: value, location: arg->getSpelling());
1665 }
1666 for (opt::Arg *arg : args.filtered(Ids: OPT_remap_inputs_file)) {
1667 StringRef filename(arg->getValue());
1668 std::optional<MemoryBufferRef> buffer = readFile(ctx, path: filename);
1669 if (!buffer)
1670 continue;
1671 // Parse 'from-glob=to-file' lines, ignoring #-led comments.
1672 for (auto [lineno, line] : llvm::enumerate(First: args::getLines(mb: *buffer)))
1673 if (remapInputs(ctx, line, location: filename + ":" + Twine(lineno + 1)))
1674 break;
1675 }
1676
1677 for (opt::Arg *arg : args.filtered(Ids: OPT_shuffle_sections)) {
1678 constexpr StringRef errPrefix = "--shuffle-sections=: ";
1679 std::pair<StringRef, StringRef> kv = StringRef(arg->getValue()).split(Separator: '=');
1680 if (kv.first.empty() || kv.second.empty()) {
1681 ErrAlways(ctx) << errPrefix << "expected <section_glob>=<seed>, but got '"
1682 << arg->getValue() << "'";
1683 continue;
1684 }
1685 // Signed so that <section_glob>=-1 is allowed.
1686 int64_t v;
1687 if (!to_integer(S: kv.second, Num&: v))
1688 ErrAlways(ctx) << errPrefix << "expected an integer, but got '"
1689 << kv.second << "'";
1690 else if (Expected<GlobPattern> pat = GlobPattern::create(Pat: kv.first))
1691 ctx.arg.shuffleSections.emplace_back(Args: std::move(*pat), Args: uint32_t(v));
1692 else
1693 ErrAlways(ctx) << errPrefix << pat.takeError() << ": " << kv.first;
1694 }
1695
1696 auto reports = {
1697 std::make_pair(x: "bti-report", y: &ctx.arg.zBtiReport),
1698 std::make_pair(x: "cet-report", y: &ctx.arg.zCetReport),
1699 std::make_pair(x: "execute-only-report", y: &ctx.arg.zExecuteOnlyReport),
1700 std::make_pair(x: "gcs-report", y: &ctx.arg.zGcsReport),
1701 std::make_pair(x: "gcs-report-dynamic", y: &ctx.arg.zGcsReportDynamic),
1702 std::make_pair(x: "pauth-report", y: &ctx.arg.zPauthReport),
1703 std::make_pair(x: "zicfilp-unlabeled-report",
1704 y: &ctx.arg.zZicfilpUnlabeledReport),
1705 std::make_pair(x: "zicfilp-func-sig-report", y: &ctx.arg.zZicfilpFuncSigReport),
1706 std::make_pair(x: "zicfiss-report", y: &ctx.arg.zZicfissReport)};
1707 bool hasGcsReportDynamic = false;
1708 for (opt::Arg *arg : args.filtered(Ids: OPT_z)) {
1709 std::pair<StringRef, StringRef> option =
1710 StringRef(arg->getValue()).split(Separator: '=');
1711 for (auto reportArg : reports) {
1712 if (option.first != reportArg.first)
1713 continue;
1714 arg->claim();
1715 if (option.second == "none")
1716 *reportArg.second = ReportPolicy::None;
1717 else if (option.second == "warning")
1718 *reportArg.second = ReportPolicy::Warning;
1719 else if (option.second == "error")
1720 *reportArg.second = ReportPolicy::Error;
1721 else {
1722 ErrAlways(ctx) << "unknown -z " << reportArg.first
1723 << "= value: " << option.second;
1724 continue;
1725 }
1726 hasGcsReportDynamic |= option.first == "gcs-report-dynamic";
1727 }
1728 }
1729
1730 // When -zgcs-report-dynamic is unspecified, it inherits -zgcs-report
1731 // but is capped at warning to avoid needing to rebuild the shared library
1732 // with GCS enabled.
1733 if (!hasGcsReportDynamic && ctx.arg.zGcsReport != ReportPolicy::None)
1734 ctx.arg.zGcsReportDynamic = ReportPolicy::Warning;
1735
1736 for (opt::Arg *arg : args.filtered(Ids: OPT_compress_sections)) {
1737 SmallVector<StringRef, 0> fields;
1738 StringRef(arg->getValue()).split(A&: fields, Separator: '=');
1739 if (fields.size() != 2 || fields[1].empty()) {
1740 ErrAlways(ctx) << arg->getSpelling()
1741 << ": parse error, not 'section-glob=[none|zlib|zstd]'";
1742 continue;
1743 }
1744 auto [typeStr, levelStr] = fields[1].split(Separator: ':');
1745 auto type = getCompressionType(ctx, s: typeStr, option: arg->getSpelling());
1746 unsigned level = 0;
1747 if (fields[1].size() != typeStr.size() &&
1748 !llvm::to_integer(S: levelStr, Num&: level)) {
1749 ErrAlways(ctx)
1750 << arg->getSpelling()
1751 << ": expected a non-negative integer compression level, but got '"
1752 << levelStr << "'";
1753 }
1754 if (Expected<GlobPattern> pat = GlobPattern::create(Pat: fields[0])) {
1755 ctx.arg.compressSections.emplace_back(Args: std::move(*pat), Args&: type, Args&: level);
1756 } else {
1757 ErrAlways(ctx) << arg->getSpelling() << ": " << pat.takeError();
1758 continue;
1759 }
1760 }
1761
1762 for (opt::Arg *arg : args.filtered(Ids: OPT_z)) {
1763 std::pair<StringRef, StringRef> option =
1764 StringRef(arg->getValue()).split(Separator: '=');
1765 if (option.first != "dead-reloc-in-nonalloc")
1766 continue;
1767 arg->claim();
1768 constexpr StringRef errPrefix = "-z dead-reloc-in-nonalloc=: ";
1769 std::pair<StringRef, StringRef> kv = option.second.split(Separator: '=');
1770 if (kv.first.empty() || kv.second.empty()) {
1771 ErrAlways(ctx) << errPrefix << "expected <section_glob>=<value>";
1772 continue;
1773 }
1774 uint64_t v;
1775 if (!to_integer(S: kv.second, Num&: v))
1776 ErrAlways(ctx) << errPrefix
1777 << "expected a non-negative integer, but got '"
1778 << kv.second << "'";
1779 else if (Expected<GlobPattern> pat = GlobPattern::create(Pat: kv.first))
1780 ctx.arg.deadRelocInNonAlloc.emplace_back(Args: std::move(*pat), Args&: v);
1781 else
1782 ErrAlways(ctx) << errPrefix << pat.takeError() << ": " << kv.first;
1783 }
1784
1785 cl::ResetAllOptionOccurrences();
1786
1787 // Parse LTO options.
1788 if (auto *arg = args.getLastArg(Ids: OPT_plugin_opt_mcpu_eq))
1789 parseClangOption(ctx, opt: ctx.saver.save(S: "-mcpu=" + StringRef(arg->getValue())),
1790 msg: arg->getSpelling());
1791
1792 for (opt::Arg *arg : args.filtered(Ids: OPT_plugin_opt_eq_minus))
1793 parseClangOption(ctx, opt: std::string("-") + arg->getValue(),
1794 msg: arg->getSpelling());
1795
1796 // GCC collect2 passes -plugin-opt=path/to/lto-wrapper with an absolute or
1797 // relative path. Just ignore. If not ended with "lto-wrapper" (or
1798 // "lto-wrapper.exe" for GCC cross-compiled for Windows), consider it an
1799 // unsupported LLVMgold.so option and error.
1800 for (opt::Arg *arg : args.filtered(Ids: OPT_plugin_opt_eq)) {
1801 StringRef v(arg->getValue());
1802 if (!v.ends_with(Suffix: "lto-wrapper") && !v.ends_with(Suffix: "lto-wrapper.exe"))
1803 ErrAlways(ctx) << arg->getSpelling() << ": unknown plugin option '"
1804 << arg->getValue() << "'";
1805 }
1806
1807 ctx.arg.passPlugins = args::getStrings(args, id: OPT_load_pass_plugins);
1808
1809 // Parse -mllvm options.
1810 for (const auto *arg : args.filtered(Ids: OPT_mllvm)) {
1811 parseClangOption(ctx, opt: arg->getValue(), msg: arg->getSpelling());
1812 ctx.arg.mllvmOpts.emplace_back(Args: arg->getValue());
1813 }
1814
1815 ctx.arg.ltoKind = LtoKind::Default;
1816 if (auto *arg = args.getLastArg(Ids: OPT_lto)) {
1817 StringRef s = arg->getValue();
1818 if (s == "thin")
1819 ctx.arg.ltoKind = LtoKind::UnifiedThin;
1820 else if (s == "full")
1821 ctx.arg.ltoKind = LtoKind::UnifiedRegular;
1822 else if (s == "default")
1823 ctx.arg.ltoKind = LtoKind::Default;
1824 else
1825 ErrAlways(ctx) << "unknown LTO mode: " << s;
1826 }
1827
1828 // --threads= takes a positive integer and provides the default value for
1829 // --thinlto-jobs=. If unspecified, cap the number of threads since
1830 // overhead outweighs optimization for used parallel algorithms for the
1831 // non-LTO parts.
1832 if (auto *arg = args.getLastArg(Ids: OPT_threads)) {
1833 StringRef v(arg->getValue());
1834 unsigned threads = 0;
1835 if (!llvm::to_integer(S: v, Num&: threads, Base: 0) || threads == 0)
1836 ErrAlways(ctx) << arg->getSpelling()
1837 << ": expected a positive integer, but got '"
1838 << arg->getValue() << "'";
1839 parallel::strategy = hardware_concurrency(ThreadCount: threads);
1840 ctx.arg.thinLTOJobs = v;
1841 } else if (parallel::strategy.compute_thread_count() > 16) {
1842 Log(ctx) << "set maximum concurrency to 16, specify --threads= to change";
1843 parallel::strategy = hardware_concurrency(ThreadCount: 16);
1844 }
1845 if (auto *arg = args.getLastArg(Ids: OPT_thinlto_jobs_eq))
1846 ctx.arg.thinLTOJobs = arg->getValue();
1847 ctx.arg.threadCount = parallel::strategy.compute_thread_count();
1848
1849 if (ctx.arg.ltoPartitions == 0)
1850 ErrAlways(ctx) << "--lto-partitions: number of threads must be > 0";
1851 if (!get_threadpool_strategy(Num: ctx.arg.thinLTOJobs))
1852 ErrAlways(ctx) << "--thinlto-jobs: invalid job count: "
1853 << ctx.arg.thinLTOJobs;
1854
1855 if (ctx.arg.splitStackAdjustSize < 0)
1856 ErrAlways(ctx) << "--split-stack-adjust-size: size must be >= 0";
1857
1858 // The text segment is traditionally the first segment, whose address equals
1859 // the base address. However, lld places the R PT_LOAD first. -Ttext-segment
1860 // is an old-fashioned option that does not play well with lld's layout.
1861 // Suggest --image-base as a likely alternative.
1862 if (args.hasArg(Ids: OPT_Ttext_segment))
1863 ErrAlways(ctx)
1864 << "-Ttext-segment is not supported. Use --image-base if you "
1865 "intend to set the base address";
1866
1867 // Parse ELF{32,64}{LE,BE} and CPU type.
1868 if (auto *arg = args.getLastArg(Ids: OPT_m)) {
1869 StringRef s = arg->getValue();
1870 std::tie(args&: ctx.arg.ekind, args&: ctx.arg.emachine, args&: ctx.arg.osabi) =
1871 parseEmulation(ctx, emul: s);
1872 ctx.arg.mipsN32Abi =
1873 (s.starts_with(Prefix: "elf32btsmipn32") || s.starts_with(Prefix: "elf32ltsmipn32"));
1874 ctx.arg.emulation = s;
1875 }
1876
1877 // Parse --hash-style={sysv,gnu,both}.
1878 if (auto *arg = args.getLastArg(Ids: OPT_hash_style)) {
1879 StringRef s = arg->getValue();
1880 if (s == "sysv")
1881 ctx.arg.sysvHash = true;
1882 else if (s == "gnu")
1883 ctx.arg.gnuHash = true;
1884 else if (s == "both")
1885 ctx.arg.sysvHash = ctx.arg.gnuHash = true;
1886 else
1887 ErrAlways(ctx) << "unknown --hash-style: " << s;
1888 }
1889
1890 if (args.hasArg(Ids: OPT_print_map))
1891 ctx.arg.mapFile = "-";
1892
1893 // Page alignment can be disabled by the -n (--nmagic) and -N (--omagic).
1894 // As PT_GNU_RELRO relies on Paging, do not create it when we have disabled
1895 // it. Also disable RELRO for -r.
1896 if (ctx.arg.nmagic || ctx.arg.omagic || ctx.arg.relocatable)
1897 ctx.arg.zRelro = false;
1898
1899 std::tie(args&: ctx.arg.buildId, args&: ctx.arg.buildIdVector) = getBuildId(ctx, args);
1900
1901 if (getZFlag(args, k1: "pack-relative-relocs", k2: "nopack-relative-relocs", defaultValue: false)) {
1902 ctx.arg.relrGlibc = true;
1903 ctx.arg.relrPackDynRelocs = true;
1904 } else {
1905 std::tie(args&: ctx.arg.androidPackDynRelocs, args&: ctx.arg.relrPackDynRelocs) =
1906 getPackDynRelocs(ctx, args);
1907 }
1908
1909 if (auto *arg = args.getLastArg(Ids: OPT_symbol_ordering_file)){
1910 if (args.hasArg(Ids: OPT_call_graph_ordering_file))
1911 ErrAlways(ctx) << "--symbol-ordering-file and --call-graph-order-file "
1912 "may not be used together";
1913 if (auto buffer = readFile(ctx, path: arg->getValue()))
1914 ctx.arg.symbolOrderingFile = getSymbolOrderingFile(ctx, mb: *buffer);
1915 }
1916
1917 assert(ctx.arg.versionDefinitions.empty());
1918 ctx.arg.versionDefinitions.push_back(
1919 Elt: {.name: "local", .id: (uint16_t)VER_NDX_LOCAL, .nonLocalPatterns: {}, .localPatterns: {}});
1920 ctx.arg.versionDefinitions.push_back(
1921 Elt: {.name: "global", .id: (uint16_t)VER_NDX_GLOBAL, .nonLocalPatterns: {}, .localPatterns: {}});
1922
1923 // If --retain-symbol-file is used, we'll keep only the symbols listed in
1924 // the file and discard all others.
1925 if (auto *arg = args.getLastArg(Ids: OPT_retain_symbols_file)) {
1926 ctx.arg.versionDefinitions[VER_NDX_LOCAL].nonLocalPatterns.push_back(
1927 Elt: {.name: "*", /*isExternCpp=*/false, /*hasWildcard=*/true});
1928 if (std::optional<MemoryBufferRef> buffer = readFile(ctx, path: arg->getValue()))
1929 for (StringRef s : args::getLines(mb: *buffer))
1930 ctx.arg.versionDefinitions[VER_NDX_GLOBAL].nonLocalPatterns.push_back(
1931 Elt: {.name: s, /*isExternCpp=*/false, /*hasWildcard=*/false});
1932 }
1933
1934 for (opt::Arg *arg : args.filtered(Ids: OPT_warn_backrefs_exclude)) {
1935 StringRef pattern(arg->getValue());
1936 if (Expected<GlobPattern> pat = GlobPattern::create(Pat: pattern))
1937 ctx.arg.warnBackrefsExclude.push_back(Elt: std::move(*pat));
1938 else
1939 ErrAlways(ctx) << arg->getSpelling() << ": " << pat.takeError() << ": "
1940 << pattern;
1941 }
1942
1943 // For -no-pie and -pie, --export-dynamic-symbol specifies defined symbols
1944 // which should be exported. For -shared, references to matched non-local
1945 // STV_DEFAULT symbols are not bound to definitions within the shared object,
1946 // even if other options express a symbolic intention: -Bsymbolic,
1947 // -Bsymbolic-functions (if STT_FUNC), --dynamic-list.
1948 for (auto *arg : args.filtered(Ids: OPT_export_dynamic_symbol))
1949 ctx.arg.dynamicList.push_back(
1950 Elt: {.name: arg->getValue(), /*isExternCpp=*/false,
1951 /*hasWildcard=*/hasWildcard(s: arg->getValue())});
1952
1953 // --export-dynamic-symbol-list specifies a list of --export-dynamic-symbol
1954 // patterns. --dynamic-list is --export-dynamic-symbol-list plus -Bsymbolic
1955 // like semantics.
1956 ctx.arg.symbolic =
1957 ctx.arg.bsymbolic == BsymbolicKind::All || args.hasArg(Ids: OPT_dynamic_list);
1958 for (auto *arg :
1959 args.filtered(Ids: OPT_dynamic_list, Ids: OPT_export_dynamic_symbol_list))
1960 if (std::optional<MemoryBufferRef> buffer = readFile(ctx, path: arg->getValue()))
1961 readDynamicList(ctx, mb: *buffer);
1962
1963 for (auto *arg : args.filtered(Ids: OPT_version_script))
1964 if (std::optional<std::string> path = searchScript(ctx, path: arg->getValue())) {
1965 if (std::optional<MemoryBufferRef> buffer = readFile(ctx, path: *path))
1966 readVersionScript(ctx, mb: *buffer);
1967 } else {
1968 ErrAlways(ctx) << "cannot find version script " << arg->getValue();
1969 }
1970}
1971
1972// Some Config members do not directly correspond to any particular
1973// command line options, but computed based on other Config values.
1974// This function initialize such members. See Config.h for the details
1975// of these values.
1976static void setConfigs(Ctx &ctx, opt::InputArgList &args) {
1977 ELFKind k = ctx.arg.ekind;
1978 uint16_t m = ctx.arg.emachine;
1979
1980 ctx.arg.copyRelocs = (ctx.arg.relocatable || ctx.arg.emitRelocs);
1981 ctx.arg.is64 = (k == ELF64LEKind || k == ELF64BEKind);
1982 ctx.arg.isLE = (k == ELF32LEKind || k == ELF64LEKind);
1983 ctx.arg.endianness = ctx.arg.isLE ? endianness::little : endianness::big;
1984 ctx.arg.isMips64EL = (k == ELF64LEKind && m == EM_MIPS);
1985 ctx.arg.isPic = ctx.arg.pie || ctx.arg.shared;
1986 ctx.arg.picThunk = args.hasArg(Ids: OPT_pic_veneer, Ids: ctx.arg.isPic);
1987 ctx.arg.wordsize = ctx.arg.is64 ? 8 : 4;
1988
1989 // ELF defines two different ways to store relocation addends as shown below:
1990 //
1991 // Rel: Addends are stored to the location where relocations are applied. It
1992 // cannot pack the full range of addend values for all relocation types, but
1993 // this only affects relocation types that we don't support emitting as
1994 // dynamic relocations (see getDynRel).
1995 // Rela: Addends are stored as part of relocation entry.
1996 //
1997 // In other words, Rela makes it easy to read addends at the price of extra
1998 // 4 or 8 byte for each relocation entry.
1999 //
2000 // We pick the format for dynamic relocations according to the psABI for each
2001 // processor, but a contrary choice can be made if the dynamic loader
2002 // supports.
2003 ctx.arg.isRela = getIsRela(ctx, args);
2004
2005 // If the output uses REL relocations we must store the dynamic relocation
2006 // addends to the output sections. We also store addends for RELA relocations
2007 // if --apply-dynamic-relocs is used.
2008 // We default to not writing the addends when using RELA relocations since
2009 // any standard conforming tool can find it in r_addend.
2010 ctx.arg.writeAddends = args.hasFlag(Pos: OPT_apply_dynamic_relocs,
2011 Neg: OPT_no_apply_dynamic_relocs, Default: false) ||
2012 !ctx.arg.isRela;
2013 // Validation of dynamic relocation addends is on by default for assertions
2014 // builds and disabled otherwise. This check is enabled when writeAddends is
2015 // true.
2016#ifndef NDEBUG
2017 bool checkDynamicRelocsDefault = true;
2018#else
2019 bool checkDynamicRelocsDefault = false;
2020#endif
2021 ctx.arg.checkDynamicRelocs =
2022 args.hasFlag(Pos: OPT_check_dynamic_relocations,
2023 Neg: OPT_no_check_dynamic_relocations, Default: checkDynamicRelocsDefault);
2024 ctx.arg.tocOptimize =
2025 args.hasFlag(Pos: OPT_toc_optimize, Neg: OPT_no_toc_optimize, Default: m == EM_PPC64);
2026 ctx.arg.pcRelOptimize =
2027 args.hasFlag(Pos: OPT_pcrel_optimize, Neg: OPT_no_pcrel_optimize, Default: m == EM_PPC64);
2028
2029 if (!args.hasArg(Ids: OPT_hash_style)) {
2030 if (ctx.arg.emachine == EM_MIPS)
2031 ctx.arg.sysvHash = true;
2032 else
2033 ctx.arg.sysvHash = ctx.arg.gnuHash = true;
2034 }
2035
2036 // Set default entry point and output file if not specified by command line or
2037 // linker scripts.
2038 ctx.arg.warnMissingEntry =
2039 (!ctx.arg.entry.empty() || (!ctx.arg.shared && !ctx.arg.relocatable));
2040 if (ctx.arg.entry.empty() && !ctx.arg.relocatable)
2041 ctx.arg.entry = ctx.arg.emachine == EM_MIPS ? "__start" : "_start";
2042 if (ctx.arg.outputFile.empty())
2043 ctx.arg.outputFile = "a.out";
2044
2045 // Fail early if the output file or map file is not writable. If a user has a
2046 // long link, e.g. due to a large LTO link, they do not wish to run it and
2047 // find that it failed because there was a mistake in their command-line.
2048 {
2049 llvm::TimeTraceScope timeScope("Create output files");
2050 if (auto e = tryCreateFile(path: ctx.arg.outputFile))
2051 ErrAlways(ctx) << "cannot open output file " << ctx.arg.outputFile << ": "
2052 << e.message();
2053 if (auto e = tryCreateFile(path: ctx.arg.mapFile))
2054 ErrAlways(ctx) << "cannot open map file " << ctx.arg.mapFile << ": "
2055 << e.message();
2056 if (auto e = tryCreateFile(path: ctx.arg.whyExtract))
2057 ErrAlways(ctx) << "cannot open --why-extract= file " << ctx.arg.whyExtract
2058 << ": " << e.message();
2059 }
2060}
2061
2062static bool isFormatBinary(Ctx &ctx, StringRef s) {
2063 if (s == "binary")
2064 return true;
2065 if (s == "elf" || s == "default")
2066 return false;
2067 ErrAlways(ctx) << "unknown --format value: " << s
2068 << " (supported formats: elf, default, binary)";
2069 return false;
2070}
2071
2072void LinkerDriver::createFiles(opt::InputArgList &args) {
2073 llvm::TimeTraceScope timeScope("Load input files");
2074 // For --{push,pop}-state.
2075 std::vector<std::tuple<bool, bool, bool>> stack;
2076
2077 // -r implies -Bstatic and has precedence over -Bdynamic.
2078 ctx.arg.isStatic = ctx.arg.relocatable;
2079
2080 // Iterate over argv to process input files and positional arguments.
2081 std::optional<MemoryBufferRef> defaultScript;
2082 nextGroupId = 0;
2083 isInGroup = false;
2084 bool hasInput = false, hasScript = false;
2085 for (auto *arg : args) {
2086 switch (arg->getOption().getID()) {
2087 case OPT_library:
2088 addLibrary(name: arg->getValue());
2089 hasInput = true;
2090 break;
2091 case OPT_INPUT:
2092 addFile(path: arg->getValue(), /*withLOption=*/false);
2093 hasInput = true;
2094 break;
2095 case OPT_defsym: {
2096 readDefsym(ctx, mb: MemoryBufferRef(arg->getValue(), "--defsym"));
2097 break;
2098 }
2099 case OPT_script:
2100 case OPT_default_script:
2101 if (std::optional<std::string> path =
2102 searchScript(ctx, path: arg->getValue())) {
2103 if (std::optional<MemoryBufferRef> mb = readFile(ctx, path: *path)) {
2104 if (arg->getOption().matches(ID: OPT_default_script)) {
2105 defaultScript = mb;
2106 } else {
2107 readLinkerScript(ctx, mb: *mb);
2108 hasScript = true;
2109 }
2110 }
2111 break;
2112 }
2113 ErrAlways(ctx) << "cannot find linker script " << arg->getValue();
2114 break;
2115 case OPT_as_needed:
2116 ctx.arg.asNeeded = true;
2117 break;
2118 case OPT_format:
2119 ctx.arg.formatBinary = isFormatBinary(ctx, s: arg->getValue());
2120 break;
2121 case OPT_no_as_needed:
2122 ctx.arg.asNeeded = false;
2123 break;
2124 case OPT_Bstatic:
2125 case OPT_omagic:
2126 case OPT_nmagic:
2127 ctx.arg.isStatic = true;
2128 break;
2129 case OPT_Bdynamic:
2130 if (!ctx.arg.relocatable)
2131 ctx.arg.isStatic = false;
2132 break;
2133 case OPT_whole_archive:
2134 inWholeArchive = true;
2135 break;
2136 case OPT_no_whole_archive:
2137 inWholeArchive = false;
2138 break;
2139 case OPT_just_symbols:
2140 if (std::optional<MemoryBufferRef> mb = readFile(ctx, path: arg->getValue())) {
2141 files.push_back(Elt: createObjFile(ctx, mb: *mb));
2142 files.back()->justSymbols = true;
2143 }
2144 break;
2145 case OPT_in_implib:
2146 if (armCmseImpLib)
2147 ErrAlways(ctx) << "multiple CMSE import libraries not supported";
2148 else if (std::optional<MemoryBufferRef> mb =
2149 readFile(ctx, path: arg->getValue()))
2150 armCmseImpLib = createObjFile(ctx, mb: *mb);
2151 break;
2152 case OPT_start_group:
2153 if (isInGroup)
2154 ErrAlways(ctx) << "nested --start-group";
2155 isInGroup = true;
2156 break;
2157 case OPT_end_group:
2158 if (!isInGroup)
2159 ErrAlways(ctx) << "stray --end-group";
2160 isInGroup = false;
2161 ++nextGroupId;
2162 break;
2163 case OPT_start_lib:
2164 if (inLib)
2165 ErrAlways(ctx) << "nested --start-lib";
2166 if (isInGroup)
2167 ErrAlways(ctx) << "may not nest --start-lib in --start-group";
2168 inLib = true;
2169 isInGroup = true;
2170 break;
2171 case OPT_end_lib:
2172 if (!inLib)
2173 ErrAlways(ctx) << "stray --end-lib";
2174 inLib = false;
2175 isInGroup = false;
2176 ++nextGroupId;
2177 break;
2178 case OPT_push_state:
2179 stack.emplace_back(args&: ctx.arg.asNeeded, args&: ctx.arg.isStatic, args&: inWholeArchive);
2180 break;
2181 case OPT_pop_state:
2182 if (stack.empty()) {
2183 ErrAlways(ctx) << "unbalanced --push-state/--pop-state";
2184 break;
2185 }
2186 std::tie(args&: ctx.arg.asNeeded, args&: ctx.arg.isStatic, args&: inWholeArchive) =
2187 stack.back();
2188 stack.pop_back();
2189 break;
2190 }
2191 }
2192
2193 if (defaultScript && !hasScript)
2194 readLinkerScript(ctx, mb: *defaultScript);
2195 if (files.empty() && !hasInput && errCount(ctx) == 0)
2196 ErrAlways(ctx) << "no input files";
2197}
2198
2199// If -m <machine_type> was not given, infer it from object files.
2200void LinkerDriver::inferMachineType() {
2201 if (ctx.arg.ekind != ELFNoneKind)
2202 return;
2203
2204 bool inferred = false;
2205 for (auto &f : files) {
2206 if (f->ekind == ELFNoneKind)
2207 continue;
2208 if (!inferred) {
2209 inferred = true;
2210 ctx.arg.ekind = f->ekind;
2211 ctx.arg.emachine = f->emachine;
2212 ctx.arg.mipsN32Abi = ctx.arg.emachine == EM_MIPS && isMipsN32Abi(ctx, f: *f);
2213 }
2214 ctx.arg.osabi = f->osabi;
2215 if (f->osabi != ELFOSABI_NONE)
2216 return;
2217 }
2218 if (!inferred)
2219 ErrAlways(ctx)
2220 << "target emulation unknown: -m or at least one .o file required";
2221}
2222
2223// Parse -z max-page-size=<value>. The default value is defined by
2224// each target.
2225static uint64_t getMaxPageSize(Ctx &ctx, opt::InputArgList &args) {
2226 uint64_t val = args::getZOptionValue(args, id: OPT_z, key: "max-page-size",
2227 Default: ctx.target->defaultMaxPageSize);
2228 if (!isPowerOf2_64(Value: val)) {
2229 ErrAlways(ctx) << "max-page-size: value isn't a power of 2";
2230 return ctx.target->defaultMaxPageSize;
2231 }
2232 if (ctx.arg.nmagic || ctx.arg.omagic) {
2233 if (val != ctx.target->defaultMaxPageSize)
2234 Warn(ctx)
2235 << "-z max-page-size set, but paging disabled by omagic or nmagic";
2236 return 1;
2237 }
2238 return val;
2239}
2240
2241// Parse -z common-page-size=<value>. The default value is defined by
2242// each target.
2243static uint64_t getCommonPageSize(Ctx &ctx, opt::InputArgList &args) {
2244 uint64_t val = args::getZOptionValue(args, id: OPT_z, key: "common-page-size",
2245 Default: ctx.target->defaultCommonPageSize);
2246 if (!isPowerOf2_64(Value: val)) {
2247 ErrAlways(ctx) << "common-page-size: value isn't a power of 2";
2248 return ctx.target->defaultCommonPageSize;
2249 }
2250 if (ctx.arg.nmagic || ctx.arg.omagic) {
2251 if (val != ctx.target->defaultCommonPageSize)
2252 Warn(ctx)
2253 << "-z common-page-size set, but paging disabled by omagic or nmagic";
2254 return 1;
2255 }
2256 // commonPageSize can't be larger than maxPageSize.
2257 if (val > ctx.arg.maxPageSize)
2258 val = ctx.arg.maxPageSize;
2259 return val;
2260}
2261
2262// Parses --image-base option.
2263static std::optional<uint64_t> getImageBase(Ctx &ctx, opt::InputArgList &args) {
2264 // Because we are using `ctx.arg.maxPageSize` here, this function has to be
2265 // called after the variable is initialized.
2266 auto *arg = args.getLastArg(Ids: OPT_image_base);
2267 if (!arg)
2268 return std::nullopt;
2269
2270 StringRef s = arg->getValue();
2271 uint64_t v;
2272 if (!to_integer(S: s, Num&: v)) {
2273 ErrAlways(ctx) << "--image-base: number expected, but got " << s;
2274 return 0;
2275 }
2276 if ((v % ctx.arg.maxPageSize) != 0)
2277 Warn(ctx) << "--image-base: address isn't multiple of page size: " << s;
2278 return v;
2279}
2280
2281// Parses `--exclude-libs=lib,lib,...`.
2282// The library names may be delimited by commas or colons.
2283static DenseSet<StringRef> getExcludeLibs(opt::InputArgList &args) {
2284 DenseSet<StringRef> ret;
2285 for (auto *arg : args.filtered(Ids: OPT_exclude_libs)) {
2286 StringRef s = arg->getValue();
2287 for (;;) {
2288 size_t pos = s.find_first_of(Chars: ",:");
2289 if (pos == StringRef::npos)
2290 break;
2291 ret.insert(V: s.substr(Start: 0, N: pos));
2292 s = s.substr(Start: pos + 1);
2293 }
2294 ret.insert(V: s);
2295 }
2296 return ret;
2297}
2298
2299// Handles the --exclude-libs option. If a static library file is specified
2300// by the --exclude-libs option, all public symbols from the archive become
2301// private unless otherwise specified by version scripts or something.
2302// A special library name "ALL" means all archive files.
2303//
2304// This is not a popular option, but some programs such as bionic libc use it.
2305static void excludeLibs(Ctx &ctx, opt::InputArgList &args) {
2306 DenseSet<StringRef> libs = getExcludeLibs(args);
2307 bool all = libs.count(V: "ALL");
2308
2309 auto visit = [&](InputFile *file) {
2310 if (file->archiveName.empty() ||
2311 !(all || libs.count(V: path::filename(path: file->archiveName))))
2312 return;
2313 ArrayRef<Symbol *> symbols = file->getSymbols();
2314 if (isa<ELFFileBase>(Val: file))
2315 symbols = cast<ELFFileBase>(Val: file)->getGlobalSymbols();
2316 for (Symbol *sym : symbols) {
2317 if (!sym->isUndefined() && sym->file == file) {
2318 sym->versionId = VER_NDX_LOCAL;
2319 sym->isExported = false;
2320 }
2321 }
2322 };
2323
2324 for (ELFFileBase *file : ctx.objectFiles)
2325 visit(file);
2326
2327 for (BitcodeFile *file : ctx.bitcodeFiles)
2328 visit(file);
2329}
2330
2331// Force Sym to be entered in the output.
2332static void handleUndefined(Ctx &ctx, Symbol *sym, const char *option) {
2333 // Since a symbol may not be used inside the program, LTO may
2334 // eliminate it. Mark the symbol as "used" to prevent it.
2335 sym->isUsedInRegularObj = true;
2336
2337 if (!sym->isLazy())
2338 return;
2339 sym->extract(ctx);
2340 if (!ctx.arg.whyExtract.empty())
2341 ctx.whyExtractRecords.emplace_back(Args&: option, Args&: sym->file, Args&: *sym);
2342}
2343
2344// As an extension to GNU linkers, lld supports a variant of `-u`
2345// which accepts wildcard patterns. All symbols that match a given
2346// pattern are handled as if they were given by `-u`.
2347static void handleUndefinedGlob(Ctx &ctx, StringRef arg) {
2348 Expected<GlobPattern> pat = GlobPattern::create(Pat: arg);
2349 if (!pat) {
2350 ErrAlways(ctx) << "--undefined-glob: " << pat.takeError() << ": " << arg;
2351 return;
2352 }
2353
2354 // Calling sym->extract() in the loop is not safe because it may add new
2355 // symbols to the symbol table, invalidating the current iterator.
2356 SmallVector<Symbol *, 0> syms;
2357 for (Symbol *sym : ctx.symtab->getSymbols())
2358 if (!sym->isPlaceholder() && pat->match(S: sym->getName()))
2359 syms.push_back(Elt: sym);
2360
2361 for (Symbol *sym : syms)
2362 handleUndefined(ctx, sym, option: "--undefined-glob");
2363}
2364
2365static void handleLibcall(Ctx &ctx, StringRef name) {
2366 Symbol *sym = ctx.symtab->find(name);
2367 if (sym && sym->isLazy() && isa<BitcodeFile>(Val: sym->file)) {
2368 if (!ctx.arg.whyExtract.empty())
2369 ctx.whyExtractRecords.emplace_back(Args: "<libcall>", Args&: sym->file, Args&: *sym);
2370 sym->extract(ctx);
2371 }
2372}
2373
2374static void writeArchiveStats(Ctx &ctx) {
2375 if (ctx.arg.printArchiveStats.empty())
2376 return;
2377
2378 std::error_code ec;
2379 raw_fd_ostream os = ctx.openAuxiliaryFile(filename: ctx.arg.printArchiveStats, ec);
2380 if (ec) {
2381 ErrAlways(ctx) << "--print-archive-stats=: cannot open "
2382 << ctx.arg.printArchiveStats << ": " << ec.message();
2383 return;
2384 }
2385
2386 os << "members\textracted\tarchive\n";
2387
2388 DenseMap<CachedHashStringRef, unsigned> extracted;
2389 for (ELFFileBase *file : ctx.objectFiles)
2390 if (file->archiveName.size())
2391 ++extracted[CachedHashStringRef(file->archiveName)];
2392 for (BitcodeFile *file : ctx.bitcodeFiles)
2393 if (file->archiveName.size())
2394 ++extracted[CachedHashStringRef(file->archiveName)];
2395 for (std::pair<StringRef, unsigned> f : ctx.driver.archiveFiles) {
2396 unsigned &v = extracted[CachedHashString(f.first)];
2397 os << f.second << '\t' << v << '\t' << f.first << '\n';
2398 // If the archive occurs multiple times, other instances have a count of 0.
2399 v = 0;
2400 }
2401}
2402
2403static void writeWhyExtract(Ctx &ctx) {
2404 if (ctx.arg.whyExtract.empty())
2405 return;
2406
2407 std::error_code ec;
2408 raw_fd_ostream os = ctx.openAuxiliaryFile(filename: ctx.arg.whyExtract, ec);
2409 if (ec) {
2410 ErrAlways(ctx) << "cannot open --why-extract= file " << ctx.arg.whyExtract
2411 << ": " << ec.message();
2412 return;
2413 }
2414
2415 os << "reference\textracted\tsymbol\n";
2416 for (auto &entry : ctx.whyExtractRecords) {
2417 os << std::get<0>(t&: entry) << '\t' << toStr(ctx, f: std::get<1>(t&: entry)) << '\t'
2418 << toStr(ctx, std::get<2>(t&: entry)) << '\n';
2419 }
2420}
2421
2422static void reportBackrefs(Ctx &ctx) {
2423 for (auto &ref : ctx.backwardReferences) {
2424 const Symbol &sym = *ref.first;
2425 std::string to = toStr(ctx, f: ref.second.second);
2426 // Some libraries have known problems and can cause noise. Filter them out
2427 // with --warn-backrefs-exclude=. The value may look like (for --start-lib)
2428 // *.o or (archive member) *.a(*.o).
2429 bool exclude = false;
2430 for (const llvm::GlobPattern &pat : ctx.arg.warnBackrefsExclude)
2431 if (pat.match(S: to)) {
2432 exclude = true;
2433 break;
2434 }
2435 if (!exclude)
2436 Warn(ctx) << "backward reference detected: " << sym.getName() << " in "
2437 << ref.second.first << " refers to " << to;
2438 }
2439}
2440
2441// Handle --dependency-file=<path>. If that option is given, lld creates a
2442// file at a given path with the following contents:
2443//
2444// <output-file>: <input-file> ...
2445//
2446// <input-file>:
2447//
2448// where <output-file> is a pathname of an output file and <input-file>
2449// ... is a list of pathnames of all input files. `make` command can read a
2450// file in the above format and interpret it as a dependency info. We write
2451// phony targets for every <input-file> to avoid an error when that file is
2452// removed.
2453//
2454// This option is useful if you want to make your final executable to depend
2455// on all input files including system libraries. Here is why.
2456//
2457// When you write a Makefile, you usually write it so that the final
2458// executable depends on all user-generated object files. Normally, you
2459// don't make your executable to depend on system libraries (such as libc)
2460// because you don't know the exact paths of libraries, even though system
2461// libraries that are linked to your executable statically are technically a
2462// part of your program. By using --dependency-file option, you can make
2463// lld to dump dependency info so that you can maintain exact dependencies
2464// easily.
2465static void writeDependencyFile(Ctx &ctx) {
2466 std::error_code ec;
2467 raw_fd_ostream os = ctx.openAuxiliaryFile(filename: ctx.arg.dependencyFile, ec);
2468 if (ec) {
2469 ErrAlways(ctx) << "cannot open " << ctx.arg.dependencyFile << ": "
2470 << ec.message();
2471 return;
2472 }
2473
2474 // We use the same escape rules as Clang/GCC which are accepted by Make/Ninja:
2475 // * A space is escaped by a backslash which itself must be escaped.
2476 // * A hash sign is escaped by a single backslash.
2477 // * $ is escapes as $$.
2478 auto printFilename = [](raw_fd_ostream &os, StringRef filename) {
2479 llvm::SmallString<256> nativePath;
2480 llvm::sys::path::native(path: filename.str(), result&: nativePath);
2481 llvm::sys::path::remove_dots(path&: nativePath, /*remove_dot_dot=*/true);
2482 for (unsigned i = 0, e = nativePath.size(); i != e; ++i) {
2483 if (nativePath[i] == '#') {
2484 os << '\\';
2485 } else if (nativePath[i] == ' ') {
2486 os << '\\';
2487 unsigned j = i;
2488 while (j > 0 && nativePath[--j] == '\\')
2489 os << '\\';
2490 } else if (nativePath[i] == '$') {
2491 os << '$';
2492 }
2493 os << nativePath[i];
2494 }
2495 };
2496
2497 os << ctx.arg.outputFile << ":";
2498 for (StringRef path : ctx.arg.dependencyFiles) {
2499 os << " \\\n ";
2500 printFilename(os, path);
2501 }
2502 os << "\n";
2503
2504 for (StringRef path : ctx.arg.dependencyFiles) {
2505 os << "\n";
2506 printFilename(os, path);
2507 os << ":\n";
2508 }
2509}
2510
2511// Replaces common symbols with defined symbols reside in .bss sections.
2512// This function is called after all symbol names are resolved. As a
2513// result, the passes after the symbol resolution won't see any
2514// symbols of type CommonSymbol.
2515static void replaceCommonSymbols(Ctx &ctx) {
2516 llvm::TimeTraceScope timeScope("Replace common symbols");
2517 for (ELFFileBase *file : ctx.objectFiles) {
2518 if (!file->hasCommonSyms)
2519 continue;
2520 for (Symbol *sym : file->getGlobalSymbols()) {
2521 auto *s = dyn_cast<CommonSymbol>(Val: sym);
2522 if (!s)
2523 continue;
2524
2525 auto *bss = make<BssSection>(args&: ctx, args: "COMMON", args&: s->size, args&: s->alignment);
2526 bss->file = s->file;
2527 ctx.inputSections.push_back(Elt: bss);
2528 Defined(ctx, s->file, StringRef(), s->binding, s->stOther, s->type,
2529 /*value=*/0, s->size, bss)
2530 .overwrite(sym&: *s);
2531 }
2532 }
2533}
2534
2535// The section referred to by `s` is considered address-significant. Set the
2536// keepUnique flag on the section if appropriate.
2537static void markAddrsig(bool icfSafe, Symbol *s) {
2538 // We don't need to keep text sections unique under --icf=all even if they
2539 // are address-significant.
2540 if (auto *d = dyn_cast_or_null<Defined>(Val: s))
2541 if (auto *sec = dyn_cast_or_null<InputSectionBase>(Val: d->section))
2542 if (icfSafe || !(sec->flags & SHF_EXECINSTR))
2543 sec->keepUnique = true;
2544}
2545
2546// Record sections that define symbols mentioned in --keep-unique <symbol>
2547// and symbols referred to by address-significance tables. These sections are
2548// ineligible for ICF.
2549template <class ELFT>
2550static void findKeepUniqueSections(Ctx &ctx, opt::InputArgList &args) {
2551 for (auto *arg : args.filtered(Ids: OPT_keep_unique)) {
2552 StringRef name = arg->getValue();
2553 auto *d = dyn_cast_or_null<Defined>(Val: ctx.symtab->find(name));
2554 if (!d || !d->section) {
2555 Warn(ctx) << "could not find symbol " << name << " to keep unique";
2556 continue;
2557 }
2558 if (auto *sec = dyn_cast<InputSectionBase>(Val: d->section))
2559 sec->keepUnique = true;
2560 }
2561
2562 // --icf=all --ignore-data-address-equality means that we can ignore
2563 // the dynsym and address-significance tables entirely.
2564 if (ctx.arg.icf == ICFLevel::All && ctx.arg.ignoreDataAddressEquality)
2565 return;
2566
2567 // Symbols in the dynsym could be address-significant in other executables
2568 // or DSOs, so we conservatively mark them as address-significant.
2569 bool icfSafe = ctx.arg.icf == ICFLevel::Safe;
2570 for (Symbol *sym : ctx.symtab->getSymbols())
2571 if (sym->isExported)
2572 markAddrsig(icfSafe, s: sym);
2573
2574 // Visit the address-significance table in each object file and mark each
2575 // referenced symbol as address-significant.
2576 for (InputFile *f : ctx.objectFiles) {
2577 auto *obj = cast<ObjFile<ELFT>>(f);
2578 ArrayRef<Symbol *> syms = obj->getSymbols();
2579 if (obj->addrsigSec) {
2580 ArrayRef<uint8_t> contents =
2581 check(obj->getObj().getSectionContents(*obj->addrsigSec));
2582 const uint8_t *cur = contents.begin();
2583 while (cur != contents.end()) {
2584 unsigned size;
2585 const char *err = nullptr;
2586 uint64_t symIndex = decodeULEB128(p: cur, n: &size, end: contents.end(), error: &err);
2587 if (err) {
2588 Err(ctx) << f << ": could not decode addrsig section: " << err;
2589 break;
2590 }
2591 markAddrsig(icfSafe, s: syms[symIndex]);
2592 cur += size;
2593 }
2594 } else {
2595 // If an object file does not have an address-significance table,
2596 // conservatively mark all of its symbols as address-significant.
2597 for (Symbol *s : syms)
2598 markAddrsig(icfSafe, s);
2599 }
2600 }
2601}
2602
2603// This function reads a symbol partition specification section. These sections
2604// are used to control which partition a symbol is allocated to. See
2605// https://lld.llvm.org/Partitions.html for more details on partitions.
2606template <typename ELFT>
2607static void readSymbolPartitionSection(Ctx &ctx, InputSectionBase *s) {
2608 // Read the relocation that refers to the partition's entry point symbol.
2609 Symbol *sym;
2610 const RelsOrRelas<ELFT> rels = s->template relsOrRelas<ELFT>();
2611 auto readEntry = [](InputFile *file, const auto &rels) -> Symbol * {
2612 for (const auto &rel : rels)
2613 return &file->getRelocTargetSym(rel);
2614 return nullptr;
2615 };
2616 if (rels.areRelocsCrel())
2617 sym = readEntry(s->file, rels.crels);
2618 else if (rels.areRelocsRel())
2619 sym = readEntry(s->file, rels.rels);
2620 else
2621 sym = readEntry(s->file, rels.relas);
2622 if (!isa_and_nonnull<Defined>(Val: sym) || !sym->isExported)
2623 return;
2624
2625 StringRef partName = reinterpret_cast<const char *>(s->content().data());
2626 for (Partition &part : ctx.partitions) {
2627 if (part.name == partName) {
2628 sym->partition = part.getNumber(ctx);
2629 return;
2630 }
2631 }
2632
2633 // Forbid partitions from being used on incompatible targets, and forbid them
2634 // from being used together with various linker features that assume a single
2635 // set of output sections.
2636 if (ctx.script->hasSectionsCommand)
2637 ErrAlways(ctx) << s->file
2638 << ": partitions cannot be used with the SECTIONS command";
2639 if (ctx.script->hasPhdrsCommands())
2640 ErrAlways(ctx) << s->file
2641 << ": partitions cannot be used with the PHDRS command";
2642 if (!ctx.arg.sectionStartMap.empty())
2643 ErrAlways(ctx) << s->file
2644 << ": partitions cannot be used with "
2645 "--section-start, -Ttext, -Tdata or -Tbss";
2646 if (ctx.arg.emachine == EM_MIPS)
2647 ErrAlways(ctx) << s->file << ": partitions cannot be used on this target";
2648
2649 // Impose a limit of no more than 254 partitions. This limit comes from the
2650 // sizes of the Partition fields in InputSectionBase and Symbol, as well as
2651 // the amount of space devoted to the partition number in RankFlags.
2652 if (ctx.partitions.size() == 254)
2653 Fatal(ctx) << "may not have more than 254 partitions";
2654
2655 ctx.partitions.emplace_back(args&: ctx);
2656 Partition &newPart = ctx.partitions.back();
2657 newPart.name = partName;
2658 sym->partition = newPart.getNumber(ctx);
2659}
2660
2661static void markBuffersAsDontNeed(Ctx &ctx, bool skipLinkedOutput) {
2662 // With --thinlto-index-only, all buffers are nearly unused from now on
2663 // (except symbol/section names used by infrequent passes). Mark input file
2664 // buffers as MADV_DONTNEED so that these pages can be reused by the expensive
2665 // thin link, saving memory.
2666 if (skipLinkedOutput) {
2667 for (MemoryBuffer &mb : llvm::make_pointee_range(Range&: ctx.memoryBuffers))
2668 mb.dontNeedIfMmap();
2669 return;
2670 }
2671
2672 // Otherwise, just mark MemoryBuffers backing BitcodeFiles.
2673 DenseSet<const char *> bufs;
2674 for (BitcodeFile *file : ctx.bitcodeFiles)
2675 bufs.insert(V: file->mb.getBufferStart());
2676 for (BitcodeFile *file : ctx.lazyBitcodeFiles)
2677 bufs.insert(V: file->mb.getBufferStart());
2678 for (MemoryBuffer &mb : llvm::make_pointee_range(Range&: ctx.memoryBuffers))
2679 if (bufs.count(V: mb.getBufferStart()))
2680 mb.dontNeedIfMmap();
2681}
2682
2683// This function is where all the optimizations of link-time
2684// optimization takes place. When LTO is in use, some input files are
2685// not in native object file format but in the LLVM bitcode format.
2686// This function compiles bitcode files into a few big native files
2687// using LLVM functions and replaces bitcode symbols with the results.
2688// Because all bitcode files that the program consists of are passed to
2689// the compiler at once, it can do a whole-program optimization.
2690template <class ELFT>
2691void LinkerDriver::compileBitcodeFiles(bool skipLinkedOutput) {
2692 llvm::TimeTraceScope timeScope("LTO");
2693 // Compile bitcode files and replace bitcode symbols.
2694 lto.reset(p: new BitcodeCompiler(ctx));
2695 for (BitcodeFile *file : ctx.bitcodeFiles)
2696 lto->add(f&: *file);
2697
2698 if (!ctx.bitcodeFiles.empty())
2699 markBuffersAsDontNeed(ctx, skipLinkedOutput);
2700
2701 ltoObjectFiles = lto->compile();
2702 for (auto &file : ltoObjectFiles) {
2703 auto *obj = cast<ObjFile<ELFT>>(file.get());
2704 obj->parse(/*ignoreComdats=*/true);
2705
2706 // This is only needed for AArch64 PAuth to set correct key in AUTH GOT
2707 // entry based on symbol type (STT_FUNC or not).
2708 // TODO: check if PAuth is actually used.
2709 if (ctx.arg.emachine == EM_AARCH64) {
2710 for (typename ELFT::Sym elfSym : obj->template getGlobalELFSyms<ELFT>()) {
2711 StringRef elfSymName = check(elfSym.getName(obj->getStringTable()));
2712 if (Symbol *sym = ctx.symtab->find(name: elfSymName))
2713 if (sym->type == STT_NOTYPE)
2714 sym->type = elfSym.getType();
2715 }
2716 }
2717
2718 // For defined symbols in non-relocatable output,
2719 // compute isExported and parse '@'.
2720 if (!ctx.arg.relocatable)
2721 for (Symbol *sym : obj->getGlobalSymbols()) {
2722 if (!sym->isDefined())
2723 continue;
2724 if (ctx.arg.exportDynamic && sym->computeBinding(ctx) != STB_LOCAL)
2725 sym->isExported = true;
2726 if (sym->hasVersionSuffix)
2727 sym->parseSymbolVersion(ctx);
2728 }
2729 ctx.objectFiles.push_back(Elt: obj);
2730 }
2731}
2732
2733// The --wrap option is a feature to rename symbols so that you can write
2734// wrappers for existing functions. If you pass `--wrap=foo`, all
2735// occurrences of symbol `foo` are resolved to `__wrap_foo` (so, you are
2736// expected to write `__wrap_foo` function as a wrapper). The original
2737// symbol becomes accessible as `__real_foo`, so you can call that from your
2738// wrapper.
2739//
2740// This data structure is instantiated for each --wrap option.
2741struct WrappedSymbol {
2742 Symbol *sym;
2743 Symbol *real;
2744 Symbol *wrap;
2745};
2746
2747// Handles --wrap option.
2748//
2749// This function instantiates wrapper symbols. At this point, they seem
2750// like they are not being used at all, so we explicitly set some flags so
2751// that LTO won't eliminate them.
2752static std::vector<WrappedSymbol> addWrappedSymbols(Ctx &ctx,
2753 opt::InputArgList &args) {
2754 std::vector<WrappedSymbol> v;
2755 DenseSet<StringRef> seen;
2756 auto &ss = ctx.saver;
2757 for (auto *arg : args.filtered(Ids: OPT_wrap)) {
2758 StringRef name = arg->getValue();
2759 if (!seen.insert(V: name).second)
2760 continue;
2761
2762 Symbol *sym = ctx.symtab->find(name);
2763 if (!sym)
2764 continue;
2765
2766 Symbol *wrap =
2767 ctx.symtab->addUnusedUndefined(name: ss.save(S: "__wrap_" + name), binding: sym->binding);
2768
2769 // If __real_ is referenced, pull in the symbol if it is lazy. Do this after
2770 // processing __wrap_ as that may have referenced __real_.
2771 StringRef realName = ctx.saver.save(S: "__real_" + name);
2772 if (Symbol *real = ctx.symtab->find(name: realName)) {
2773 ctx.symtab->addUnusedUndefined(name, binding: sym->binding);
2774 // Update sym's binding, which will replace real's later in
2775 // SymbolTable::wrap.
2776 sym->binding = real->binding;
2777 }
2778
2779 Symbol *real = ctx.symtab->addUnusedUndefined(name: realName);
2780 v.push_back(x: {.sym: sym, .real: real, .wrap: wrap});
2781
2782 // We want to tell LTO not to inline symbols to be overwritten
2783 // because LTO doesn't know the final symbol contents after renaming.
2784 real->scriptDefined = true;
2785 sym->scriptDefined = true;
2786
2787 // If a symbol is referenced in any object file, bitcode file or shared
2788 // object, mark its redirection target (foo for __real_foo and __wrap_foo
2789 // for foo) as referenced after redirection, which will be used to tell LTO
2790 // to not eliminate the redirection target. If the object file defining the
2791 // symbol also references it, we cannot easily distinguish the case from
2792 // cases where the symbol is not referenced. Retain the redirection target
2793 // in this case because we choose to wrap symbol references regardless of
2794 // whether the symbol is defined
2795 // (https://sourceware.org/bugzilla/show_bug.cgi?id=26358).
2796 if (real->referenced || real->isDefined())
2797 sym->referencedAfterWrap = true;
2798 if (sym->referenced || sym->isDefined())
2799 wrap->referencedAfterWrap = true;
2800 }
2801 return v;
2802}
2803
2804static void combineVersionedSymbol(Ctx &ctx, Symbol &sym,
2805 DenseMap<Symbol *, Symbol *> &map) {
2806 const char *suffix1 = sym.getVersionSuffix();
2807 if (suffix1[0] != '@' || suffix1[1] == '@')
2808 return;
2809
2810 // Check the existing symbol foo. We have two special cases to handle:
2811 //
2812 // * There is a definition of foo@v1 and foo@@v1.
2813 // * There is a definition of foo@v1 and foo.
2814 Defined *sym2 = dyn_cast_or_null<Defined>(Val: ctx.symtab->find(name: sym.getName()));
2815 if (!sym2)
2816 return;
2817 const char *suffix2 = sym2->getVersionSuffix();
2818 if (suffix2[0] == '@' && suffix2[1] == '@' &&
2819 strcmp(s1: suffix1 + 1, s2: suffix2 + 2) == 0) {
2820 // foo@v1 and foo@@v1 should be merged, so redirect foo@v1 to foo@@v1.
2821 map.try_emplace(Key: &sym, Args&: sym2);
2822 // If both foo@v1 and foo@@v1 are defined and non-weak, report a
2823 // duplicate definition error.
2824 if (sym.isDefined()) {
2825 sym2->checkDuplicate(ctx, other: cast<Defined>(Val&: sym));
2826 sym2->resolve(ctx, other: cast<Defined>(Val&: sym));
2827 } else if (sym.isUndefined()) {
2828 sym2->resolve(ctx, other: cast<Undefined>(Val&: sym));
2829 } else {
2830 sym2->resolve(ctx, other: cast<SharedSymbol>(Val&: sym));
2831 }
2832 // Eliminate foo@v1 from the symbol table.
2833 sym.symbolKind = Symbol::PlaceholderKind;
2834 sym.isUsedInRegularObj = false;
2835 } else if (auto *sym1 = dyn_cast<Defined>(Val: &sym)) {
2836 if (sym2->versionId > VER_NDX_GLOBAL
2837 ? ctx.arg.versionDefinitions[sym2->versionId].name == suffix1 + 1
2838 : sym1->section == sym2->section && sym1->value == sym2->value) {
2839 // Due to an assembler design flaw, if foo is defined, .symver foo,
2840 // foo@v1 defines both foo and foo@v1. Unless foo is bound to a
2841 // different version, GNU ld makes foo@v1 canonical and eliminates
2842 // foo. Emulate its behavior, otherwise we would have foo or foo@@v1
2843 // beside foo@v1. foo@v1 and foo combining does not apply if they are
2844 // not defined in the same place.
2845 map.try_emplace(Key: sym2, Args: &sym);
2846 sym2->symbolKind = Symbol::PlaceholderKind;
2847 sym2->isUsedInRegularObj = false;
2848 }
2849 }
2850}
2851
2852// Do renaming for --wrap and foo@v1 by updating pointers to symbols.
2853//
2854// When this function is executed, only InputFiles and symbol table
2855// contain pointers to symbol objects. We visit them to replace pointers,
2856// so that wrapped symbols are swapped as instructed by the command line.
2857static void redirectSymbols(Ctx &ctx, ArrayRef<WrappedSymbol> wrapped) {
2858 llvm::TimeTraceScope timeScope("Redirect symbols");
2859 DenseMap<Symbol *, Symbol *> map;
2860 for (const WrappedSymbol &w : wrapped) {
2861 map[w.sym] = w.wrap;
2862 map[w.real] = w.sym;
2863 }
2864
2865 // If there are version definitions (versionDefinitions.size() > 2), enumerate
2866 // symbols with a non-default version (foo@v1) and check whether it should be
2867 // combined with foo or foo@@v1.
2868 if (ctx.arg.versionDefinitions.size() > 2)
2869 for (Symbol *sym : ctx.symtab->getSymbols())
2870 if (sym->hasVersionSuffix)
2871 combineVersionedSymbol(ctx, sym&: *sym, map);
2872
2873 if (map.empty())
2874 return;
2875
2876 // Update pointers in input files.
2877 parallelForEach(R&: ctx.objectFiles, Fn: [&](ELFFileBase *file) {
2878 for (Symbol *&sym : file->getMutableGlobalSymbols())
2879 if (Symbol *s = map.lookup(Val: sym))
2880 sym = s;
2881 });
2882
2883 // Update pointers in the symbol table.
2884 for (const WrappedSymbol &w : wrapped)
2885 ctx.symtab->wrap(sym: w.sym, real: w.real, wrap: w.wrap);
2886}
2887
2888// To enable CET (x86's hardware-assisted control flow enforcement), each
2889// source file must be compiled with -fcf-protection. Object files compiled
2890// with the flag contain feature flags indicating that they are compatible
2891// with CET. We enable the feature only when all object files are compatible
2892// with CET.
2893//
2894// This is also the case with AARCH64's BTI and PAC which use the similar
2895// GNU_PROPERTY_AARCH64_FEATURE_1_AND mechanism.
2896//
2897// For AArch64 PAuth-enabled object files, the core info of all of them must
2898// match. Missing info for some object files with matching info for remaining
2899// ones can be allowed (see -z pauth-report).
2900//
2901// RISC-V Zicfilp/Zicfiss extension also use the same mechanism to record
2902// enabled features in the GNU_PROPERTY_RISCV_FEATURE_1_AND bit mask.
2903static void readSecurityNotes(Ctx &ctx) {
2904 if (ctx.arg.emachine != EM_386 && ctx.arg.emachine != EM_X86_64 &&
2905 ctx.arg.emachine != EM_AARCH64 && ctx.arg.emachine != EM_RISCV)
2906 return;
2907
2908 ctx.arg.andFeatures = -1;
2909
2910 StringRef referenceFileName;
2911 if (ctx.arg.emachine == EM_AARCH64) {
2912 auto it = llvm::find_if(Range&: ctx.objectFiles, P: [](const ELFFileBase *f) {
2913 return f->aarch64PauthAbiCoreInfo.has_value();
2914 });
2915 if (it != ctx.objectFiles.end()) {
2916 ctx.aarch64PauthAbiCoreInfo = (*it)->aarch64PauthAbiCoreInfo;
2917 referenceFileName = (*it)->getName();
2918 }
2919 }
2920 bool hasValidPauthAbiCoreInfo =
2921 ctx.aarch64PauthAbiCoreInfo && ctx.aarch64PauthAbiCoreInfo->isValid();
2922
2923 auto report = [&](ReportPolicy policy) -> ELFSyncStream {
2924 return {ctx, toDiagLevel(policy)};
2925 };
2926 auto reportUnless = [&](ReportPolicy policy, bool cond) -> ELFSyncStream {
2927 if (cond)
2928 return {ctx, DiagLevel::None};
2929 return {ctx, toDiagLevel(policy)};
2930 };
2931 for (ELFFileBase *f : ctx.objectFiles) {
2932 uint32_t features = f->andFeatures;
2933
2934 reportUnless(ctx.arg.zBtiReport,
2935 features & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)
2936 << f
2937 << ": -z bti-report: file does not have "
2938 "GNU_PROPERTY_AARCH64_FEATURE_1_BTI property";
2939
2940 reportUnless(ctx.arg.zGcsReport,
2941 features & GNU_PROPERTY_AARCH64_FEATURE_1_GCS)
2942 << f
2943 << ": -z gcs-report: file does not have "
2944 "GNU_PROPERTY_AARCH64_FEATURE_1_GCS property";
2945
2946 reportUnless(ctx.arg.zCetReport, features & GNU_PROPERTY_X86_FEATURE_1_IBT)
2947 << f
2948 << ": -z cet-report: file does not have "
2949 "GNU_PROPERTY_X86_FEATURE_1_IBT property";
2950
2951 reportUnless(ctx.arg.zCetReport,
2952 features & GNU_PROPERTY_X86_FEATURE_1_SHSTK)
2953 << f
2954 << ": -z cet-report: file does not have "
2955 "GNU_PROPERTY_X86_FEATURE_1_SHSTK property";
2956
2957 if (ctx.arg.emachine == EM_RISCV) {
2958 reportUnless(ctx.arg.zZicfilpUnlabeledReport,
2959 features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED)
2960 << f
2961 << ": -z zicfilp-unlabeled-report: file does not have "
2962 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED property";
2963
2964 reportUnless(ctx.arg.zZicfilpFuncSigReport,
2965 features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG)
2966 << f
2967 << ": -z zicfilp-func-sig-report: file does not have "
2968 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG property";
2969
2970 if ((features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED) &&
2971 (features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG))
2972 Err(ctx) << f
2973 << ": file has conflicting properties: "
2974 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED and "
2975 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG";
2976
2977 reportUnless(ctx.arg.zZicfissReport,
2978 features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_SS)
2979 << f
2980 << ": -z zicfiss-report: file does not have "
2981 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_SS property";
2982
2983 if (ctx.arg.zZicfilp == ZicfilpPolicy::Unlabeled &&
2984 (features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG))
2985 Warn(ctx) << f
2986 << ": -z zicfilp=unlabeled: file has conflicting property: "
2987 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG";
2988
2989 if (ctx.arg.zZicfilp == ZicfilpPolicy::FuncSig &&
2990 (features & GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED))
2991 Warn(ctx) << f
2992 << ": -z zicfilp=func-sig: file has conflicting property: "
2993 "GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED";
2994 }
2995
2996 if (ctx.arg.zForceBti && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)) {
2997 features |= GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
2998 if (ctx.arg.zBtiReport == ReportPolicy::None)
2999 Warn(ctx) << f
3000 << ": -z force-bti: file does not have "
3001 "GNU_PROPERTY_AARCH64_FEATURE_1_BTI property";
3002 } else if (ctx.arg.zForceIbt &&
3003 !(features & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
3004 if (ctx.arg.zCetReport == ReportPolicy::None)
3005 Warn(ctx) << f
3006 << ": -z force-ibt: file does not have "
3007 "GNU_PROPERTY_X86_FEATURE_1_IBT property";
3008 features |= GNU_PROPERTY_X86_FEATURE_1_IBT;
3009 }
3010 if (ctx.arg.zPacPlt && !(hasValidPauthAbiCoreInfo ||
3011 (features & GNU_PROPERTY_AARCH64_FEATURE_1_PAC))) {
3012 Warn(ctx) << f
3013 << ": -z pac-plt: file does not have "
3014 "GNU_PROPERTY_AARCH64_FEATURE_1_PAC property and no valid "
3015 "PAuth core info present for this link job";
3016 features |= GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
3017 }
3018 ctx.arg.andFeatures &= features;
3019
3020 if (!ctx.aarch64PauthAbiCoreInfo)
3021 continue;
3022
3023 if (!f->aarch64PauthAbiCoreInfo) {
3024 report(ctx.arg.zPauthReport)
3025 << f
3026 << ": -z pauth-report: file does not have AArch64 "
3027 "PAuth core info while '"
3028 << referenceFileName << "' has one";
3029 continue;
3030 }
3031
3032 if (ctx.aarch64PauthAbiCoreInfo != f->aarch64PauthAbiCoreInfo)
3033 Err(ctx)
3034 << "incompatible values of AArch64 PAuth core info found\n"
3035 << "platform:\n"
3036 << ">>> " << referenceFileName << ": 0x"
3037 << toHex(Input: ctx.aarch64PauthAbiCoreInfo->platform, /*LowerCase=*/true)
3038 << "\n>>> " << f << ": 0x"
3039 << toHex(Input: f->aarch64PauthAbiCoreInfo->platform, /*LowerCase=*/true)
3040 << "\nversion:\n"
3041 << ">>> " << referenceFileName << ": 0x"
3042 << toHex(Input: ctx.aarch64PauthAbiCoreInfo->version, /*LowerCase=*/true)
3043 << "\n>>> " << f << ": 0x"
3044 << toHex(Input: f->aarch64PauthAbiCoreInfo->version, /*LowerCase=*/true);
3045 }
3046
3047 // Force enable Shadow Stack.
3048 if (ctx.arg.zShstk)
3049 ctx.arg.andFeatures |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
3050
3051 // Force enable/disable GCS
3052 if (ctx.arg.zGcs == GcsPolicy::Always)
3053 ctx.arg.andFeatures |= GNU_PROPERTY_AARCH64_FEATURE_1_GCS;
3054 else if (ctx.arg.zGcs == GcsPolicy::Never)
3055 ctx.arg.andFeatures &= ~GNU_PROPERTY_AARCH64_FEATURE_1_GCS;
3056
3057 if (ctx.arg.emachine == EM_RISCV) {
3058 // Force enable/disable Zicfilp.
3059 if (ctx.arg.zZicfilp == ZicfilpPolicy::Unlabeled) {
3060 ctx.arg.andFeatures |= GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED;
3061 ctx.arg.andFeatures &= ~GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG;
3062 } else if (ctx.arg.zZicfilp == ZicfilpPolicy::FuncSig) {
3063 ctx.arg.andFeatures |= GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG;
3064 ctx.arg.andFeatures &= ~GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED;
3065 } else if (ctx.arg.zZicfilp == ZicfilpPolicy::Never)
3066 ctx.arg.andFeatures &= ~(GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_UNLABELED |
3067 GNU_PROPERTY_RISCV_FEATURE_1_CFI_LP_FUNC_SIG);
3068
3069 // Force enable/disable Zicfiss.
3070 if (ctx.arg.zZicfiss == ZicfissPolicy::Always)
3071 ctx.arg.andFeatures |= GNU_PROPERTY_RISCV_FEATURE_1_CFI_SS;
3072 else if (ctx.arg.zZicfiss == ZicfissPolicy::Never)
3073 ctx.arg.andFeatures &= ~GNU_PROPERTY_RISCV_FEATURE_1_CFI_SS;
3074 }
3075
3076 // If we are utilising GCS at any stage, the sharedFiles should be checked to
3077 // ensure they also support this feature. The gcs-report-dynamic option is
3078 // used to indicate if the user wants information relating to this, and will
3079 // be set depending on the user's input, or warning if gcs-report is set to
3080 // either `warning` or `error`.
3081 if (ctx.arg.andFeatures & GNU_PROPERTY_AARCH64_FEATURE_1_GCS)
3082 for (SharedFile *f : ctx.sharedFiles)
3083 reportUnless(ctx.arg.zGcsReportDynamic,
3084 f->andFeatures & GNU_PROPERTY_AARCH64_FEATURE_1_GCS)
3085 << f
3086 << ": GCS is required by -z gcs, but this shared library lacks the "
3087 "necessary property note. The "
3088 << "dynamic loader might not enable GCS or refuse to load the "
3089 "program unless all shared library "
3090 << "dependencies have the GCS marking.";
3091}
3092
3093static void initSectionsAndLocalSyms(ELFFileBase *file, bool ignoreComdats) {
3094 switch (file->ekind) {
3095 case ELF32LEKind:
3096 cast<ObjFile<ELF32LE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
3097 break;
3098 case ELF32BEKind:
3099 cast<ObjFile<ELF32BE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
3100 break;
3101 case ELF64LEKind:
3102 cast<ObjFile<ELF64LE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
3103 break;
3104 case ELF64BEKind:
3105 cast<ObjFile<ELF64BE>>(Val: file)->initSectionsAndLocalSyms(ignoreComdats);
3106 break;
3107 default:
3108 llvm_unreachable("");
3109 }
3110}
3111
3112static void postParseObjectFile(ELFFileBase *file) {
3113 switch (file->ekind) {
3114 case ELF32LEKind:
3115 cast<ObjFile<ELF32LE>>(Val: file)->postParse();
3116 break;
3117 case ELF32BEKind:
3118 cast<ObjFile<ELF32BE>>(Val: file)->postParse();
3119 break;
3120 case ELF64LEKind:
3121 cast<ObjFile<ELF64LE>>(Val: file)->postParse();
3122 break;
3123 case ELF64BEKind:
3124 cast<ObjFile<ELF64BE>>(Val: file)->postParse();
3125 break;
3126 default:
3127 llvm_unreachable("");
3128 }
3129}
3130
3131// Do actual linking. Note that when this function is called,
3132// all linker scripts have already been parsed.
3133template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
3134 llvm::TimeTraceScope timeScope("Link", StringRef("LinkerDriver::Link"));
3135
3136 // Handle --trace-symbol.
3137 for (auto *arg : args.filtered(Ids: OPT_trace_symbol))
3138 ctx.symtab->insert(name: arg->getValue())->traced = true;
3139
3140 ctx.internalFile = createInternalFile(ctx, name: "<internal>");
3141
3142 // Handle -u/--undefined before input files. If both a.a and b.so define foo,
3143 // -u foo a.a b.so will extract a.a.
3144 for (StringRef name : ctx.arg.undefined)
3145 ctx.symtab->addUnusedUndefined(name)->referenced = true;
3146
3147 parseFiles(ctx, files);
3148
3149 // Create dynamic sections for dynamic linking and static PIE.
3150 ctx.hasDynsym = !ctx.sharedFiles.empty() || ctx.arg.isPic;
3151 ctx.arg.exportDynamic &= ctx.hasDynsym;
3152
3153 // Preemptibility of undefined symbols when ctx.hasDynsym is true. Default is
3154 // true for dynamic linking.
3155 ctx.arg.zDynamicUndefined =
3156 getZFlag(args, k1: "dynamic-undefined-weak", k2: "nodynamic-undefined-weak",
3157 defaultValue: ctx.sharedFiles.size() || ctx.arg.shared) &&
3158 ctx.hasDynsym;
3159
3160 // If an entry symbol is in a static archive, pull out that file now.
3161 if (Symbol *sym = ctx.symtab->find(name: ctx.arg.entry))
3162 handleUndefined(ctx, sym, option: "--entry");
3163
3164 // Handle the `--undefined-glob <pattern>` options.
3165 for (StringRef pat : args::getStrings(args, id: OPT_undefined_glob))
3166 handleUndefinedGlob(ctx, arg: pat);
3167
3168 // After potential archive member extraction involving ENTRY and
3169 // -u/--undefined-glob, check whether PROVIDE symbols should be defined (the
3170 // RHS may refer to definitions in just extracted object files).
3171 ctx.script->addScriptReferencedSymbolsToSymTable();
3172
3173 // Prevent LTO from removing any definition referenced by -u.
3174 for (StringRef name : ctx.arg.undefined)
3175 if (Defined *sym = dyn_cast_or_null<Defined>(Val: ctx.symtab->find(name)))
3176 sym->isUsedInRegularObj = true;
3177
3178 // Mark -init and -fini symbols so that the LTO doesn't eliminate them.
3179 if (Symbol *sym = dyn_cast_or_null<Defined>(Val: ctx.symtab->find(name: ctx.arg.init)))
3180 sym->isUsedInRegularObj = true;
3181 if (Symbol *sym = dyn_cast_or_null<Defined>(Val: ctx.symtab->find(name: ctx.arg.fini)))
3182 sym->isUsedInRegularObj = true;
3183
3184 // If any of our inputs are bitcode files, the LTO code generator may create
3185 // references to certain library functions that might not be explicit in the
3186 // bitcode file's symbol table. If any of those library functions are defined
3187 // in a bitcode file in an archive member, we need to arrange to use LTO to
3188 // compile those archive members by adding them to the link beforehand.
3189 //
3190 // However, adding all libcall symbols to the link can have undesired
3191 // consequences. For example, the libgcc implementation of
3192 // __sync_val_compare_and_swap_8 on 32-bit ARM pulls in an .init_array entry
3193 // that aborts the program if the Linux kernel does not support 64-bit
3194 // atomics, which would prevent the program from running even if it does not
3195 // use 64-bit atomics.
3196 //
3197 // Therefore, we only add libcall symbols to the link before LTO if we have
3198 // to, i.e. if the symbol's definition is in bitcode. Any other required
3199 // libcall symbols will be added to the link after LTO when we add the LTO
3200 // object file to the link.
3201 if (!ctx.bitcodeFiles.empty()) {
3202 llvm::Triple TT(ctx.bitcodeFiles.front()->obj->getTargetTriple());
3203 for (auto *s : lto::LTO::getRuntimeLibcallSymbols(TT))
3204 handleLibcall(ctx, name: s);
3205 }
3206
3207 // Archive members defining __wrap symbols may be extracted.
3208 std::vector<WrappedSymbol> wrapped = addWrappedSymbols(ctx, args);
3209
3210 // No more lazy bitcode can be extracted at this point. Do post parse work
3211 // like checking duplicate symbols.
3212 parallelForEach(ctx.objectFiles, [](ELFFileBase *file) {
3213 initSectionsAndLocalSyms(file, /*ignoreComdats=*/false);
3214 });
3215 parallelForEach(R&: ctx.objectFiles, Fn: postParseObjectFile);
3216 parallelForEach(ctx.bitcodeFiles,
3217 [](BitcodeFile *file) { file->postParse(); });
3218 for (auto &it : ctx.nonPrevailingSyms) {
3219 Symbol &sym = *it.first;
3220 Undefined(sym.file, sym.getName(), sym.binding, sym.stOther, sym.type,
3221 it.second)
3222 .overwrite(sym);
3223 cast<Undefined>(Val&: sym).nonPrevailing = true;
3224 }
3225 ctx.nonPrevailingSyms.clear();
3226 for (const DuplicateSymbol &d : ctx.duplicates)
3227 reportDuplicate(ctx, sym: *d.sym, newFile: d.file, errSec: d.section, errOffset: d.value);
3228 ctx.duplicates.clear();
3229
3230 // Return if there were name resolution errors.
3231 if (errCount(ctx))
3232 return;
3233
3234 // We want to declare linker script's symbols early,
3235 // so that we can version them.
3236 // They also might be exported if referenced by DSOs.
3237 ctx.script->declareSymbols();
3238
3239 // Handle --exclude-libs. This is before scanVersionScript() due to a
3240 // workaround for Android ndk: for a defined versioned symbol in an archive
3241 // without a version node in the version script, Android does not expect a
3242 // 'has undefined version' error in -shared --exclude-libs=ALL mode (PR36295).
3243 // GNU ld errors in this case.
3244 if (args.hasArg(Ids: OPT_exclude_libs))
3245 excludeLibs(ctx, args);
3246
3247 // Create elfHeader early. We need a dummy section in
3248 // addReservedSymbols to mark the created symbols as not absolute.
3249 ctx.out.elfHeader = std::make_unique<OutputSection>(args&: ctx, args: "", args: 0, args: SHF_ALLOC);
3250
3251 // We need to create some reserved symbols such as _end. Create them.
3252 if (!ctx.arg.relocatable)
3253 addReservedSymbols(ctx);
3254
3255 // Apply version scripts.
3256 //
3257 // For a relocatable output, version scripts don't make sense, and
3258 // parsing a symbol version string (e.g. dropping "@ver1" from a symbol
3259 // name "foo@ver1") rather do harm, so we don't call this if -r is given.
3260 if (!ctx.arg.relocatable) {
3261 llvm::TimeTraceScope timeScope("Process symbol versions");
3262 ctx.symtab->scanVersionScript();
3263
3264 parseVersionAndComputeIsPreemptible(ctx);
3265 }
3266
3267 // Skip the normal linked output if some LTO options are specified.
3268 //
3269 // For --thinlto-index-only, index file creation is performed in
3270 // compileBitcodeFiles, so we are done afterwards. --plugin-opt=emit-llvm and
3271 // --plugin-opt=emit-asm create output files in bitcode or assembly code,
3272 // respectively. When only certain thinLTO modules are specified for
3273 // compilation, the intermediate object file are the expected output.
3274 const bool skipLinkedOutput = ctx.arg.thinLTOIndexOnly || ctx.arg.emitLLVM ||
3275 ctx.arg.ltoEmitAsm ||
3276 !ctx.arg.thinLTOModulesToCompile.empty();
3277
3278 // Handle --lto-validate-all-vtables-have-type-infos.
3279 if (ctx.arg.ltoValidateAllVtablesHaveTypeInfos)
3280 ltoValidateAllVtablesHaveTypeInfos<ELFT>(ctx, args);
3281
3282 // Do link-time optimization if given files are LLVM bitcode files.
3283 // This compiles bitcode files into real object files.
3284 //
3285 // With this the symbol table should be complete. After this, no new names
3286 // except a few linker-synthesized ones will be added to the symbol table.
3287 const size_t numObjsBeforeLTO = ctx.objectFiles.size();
3288 const size_t numInputFilesBeforeLTO = ctx.driver.files.size();
3289 compileBitcodeFiles<ELFT>(skipLinkedOutput);
3290
3291 // Symbol resolution finished. Report backward reference problems,
3292 // --print-archive-stats=, and --why-extract=.
3293 reportBackrefs(ctx);
3294 writeArchiveStats(ctx);
3295 writeWhyExtract(ctx);
3296 if (errCount(ctx))
3297 return;
3298
3299 // Bail out if normal linked output is skipped due to LTO.
3300 if (skipLinkedOutput)
3301 return;
3302
3303 // compileBitcodeFiles may have produced lto.tmp object files. After this, no
3304 // more file will be added.
3305 auto newObjectFiles = ArrayRef(ctx.objectFiles).slice(N: numObjsBeforeLTO);
3306 parallelForEach(newObjectFiles, [](ELFFileBase *file) {
3307 initSectionsAndLocalSyms(file, /*ignoreComdats=*/true);
3308 });
3309 parallelForEach(R&: newObjectFiles, Fn: postParseObjectFile);
3310 for (const DuplicateSymbol &d : ctx.duplicates)
3311 reportDuplicate(ctx, sym: *d.sym, newFile: d.file, errSec: d.section, errOffset: d.value);
3312
3313 // ELF dependent libraries may have introduced new input files after LTO has
3314 // completed. This is an error if the files haven't already been parsed, since
3315 // changing the symbol table could break the semantic assumptions of LTO.
3316 auto newInputFiles = ArrayRef(ctx.driver.files).slice(N: numInputFilesBeforeLTO);
3317 if (!newInputFiles.empty()) {
3318 DenseSet<StringRef> oldFilenames;
3319 for (auto &f : ArrayRef(ctx.driver.files).slice(N: 0, M: numInputFilesBeforeLTO))
3320 oldFilenames.insert(V: f->getName());
3321 for (auto &newFile : newInputFiles)
3322 if (!oldFilenames.contains(V: newFile->getName()))
3323 Err(ctx) << "input file '" << newFile->getName() << "' added after LTO";
3324 }
3325
3326 // Handle --exclude-libs again because lto.tmp may reference additional
3327 // libcalls symbols defined in an excluded archive. This may override
3328 // versionId set by scanVersionScript() and isExported.
3329 if (args.hasArg(Ids: OPT_exclude_libs))
3330 excludeLibs(ctx, args);
3331
3332 // Record [__acle_se_<sym>, <sym>] pairs for later processing.
3333 processArmCmseSymbols(ctx);
3334
3335 // Apply symbol renames for --wrap and combine foo@v1 and foo@@v1.
3336 redirectSymbols(ctx, wrapped);
3337
3338 // Replace common symbols with regular symbols.
3339 replaceCommonSymbols(ctx);
3340
3341 {
3342 llvm::TimeTraceScope timeScope("Aggregate sections");
3343 // Now that we have a complete list of input files.
3344 // Beyond this point, no new files are added.
3345 // Aggregate all input sections into one place.
3346 for (InputFile *f : ctx.objectFiles) {
3347 for (InputSectionBase *s : f->getSections()) {
3348 if (!s || s == &InputSection::discarded)
3349 continue;
3350 if (LLVM_UNLIKELY(isa<EhInputSection>(s)))
3351 ctx.ehInputSections.push_back(Elt: cast<EhInputSection>(Val: s));
3352 else
3353 ctx.inputSections.push_back(Elt: s);
3354 }
3355 }
3356 for (BinaryFile *f : ctx.binaryFiles)
3357 for (InputSectionBase *s : f->getSections())
3358 ctx.inputSections.push_back(Elt: cast<InputSection>(Val: s));
3359 }
3360
3361 {
3362 llvm::TimeTraceScope timeScope("Strip sections");
3363 if (ctx.hasSympart.load(m: std::memory_order_relaxed)) {
3364 llvm::erase_if(ctx.inputSections, [&ctx = ctx](InputSectionBase *s) {
3365 if (s->type != SHT_LLVM_SYMPART)
3366 return false;
3367 readSymbolPartitionSection<ELFT>(ctx, s);
3368 return true;
3369 });
3370 }
3371 // We do not want to emit debug sections if --strip-all
3372 // or --strip-debug are given.
3373 if (ctx.arg.strip != StripPolicy::None) {
3374 llvm::erase_if(ctx.inputSections, [](InputSectionBase *s) {
3375 if (isDebugSection(sec: *s))
3376 return true;
3377 if (auto *isec = dyn_cast<InputSection>(Val: s))
3378 if (InputSectionBase *rel = isec->getRelocatedSection())
3379 if (isDebugSection(sec: *rel))
3380 return true;
3381
3382 return false;
3383 });
3384 }
3385 }
3386
3387 // Since we now have a complete set of input files, we can create
3388 // a .d file to record build dependencies.
3389 if (!ctx.arg.dependencyFile.empty())
3390 writeDependencyFile(ctx);
3391
3392 // Now that the number of partitions is fixed, save a pointer to the main
3393 // partition.
3394 ctx.mainPart = &ctx.partitions[0];
3395
3396 // Read .note.gnu.property sections from input object files which
3397 // contain a hint to tweak linker's and loader's behaviors.
3398 readSecurityNotes(ctx);
3399
3400 // The Target instance handles target-specific stuff, such as applying
3401 // relocations or writing a PLT section. It also contains target-dependent
3402 // values such as a default image base address.
3403 setTarget(ctx);
3404
3405 ctx.arg.eflags = ctx.target->calcEFlags();
3406 // maxPageSize (sometimes called abi page size) is the maximum page size that
3407 // the output can be run on. For example if the OS can use 4k or 64k page
3408 // sizes then maxPageSize must be 64k for the output to be useable on both.
3409 // All important alignment decisions must use this value.
3410 ctx.arg.maxPageSize = getMaxPageSize(ctx, args);
3411 // commonPageSize is the most common page size that the output will be run on.
3412 // For example if an OS can use 4k or 64k page sizes and 4k is more common
3413 // than 64k then commonPageSize is set to 4k. commonPageSize can be used for
3414 // optimizations such as DATA_SEGMENT_ALIGN in linker scripts. LLD's use of it
3415 // is limited to writing trap instructions on the last executable segment.
3416 ctx.arg.commonPageSize = getCommonPageSize(ctx, args);
3417
3418 ctx.arg.imageBase = getImageBase(ctx, args);
3419
3420 // This adds a .comment section containing a version string.
3421 if (!ctx.arg.relocatable)
3422 ctx.inputSections.push_back(Elt: createCommentSection(ctx));
3423
3424 // Split SHF_MERGE and .eh_frame sections into pieces in preparation for garbage collection.
3425 splitSections<ELFT>(ctx);
3426
3427 // Garbage collection and removal of shared symbols from unused shared objects.
3428 markLive<ELFT>(ctx);
3429
3430 // Make copies of any input sections that need to be copied into each
3431 // partition.
3432 copySectionsIntoPartitions(ctx);
3433
3434 if (canHaveMemtagGlobals(ctx)) {
3435 llvm::TimeTraceScope timeScope("Process memory tagged symbols");
3436 createTaggedSymbols(ctx);
3437 }
3438
3439 // Create synthesized sections such as .got and .plt. This is called before
3440 // processSectionCommands() so that they can be placed by SECTIONS commands.
3441 createSyntheticSections<ELFT>(ctx);
3442
3443 // Some input sections that are used for exception handling need to be moved
3444 // into synthetic sections. Do that now so that they aren't assigned to
3445 // output sections in the usual way.
3446 if (!ctx.arg.relocatable)
3447 combineEhSections(ctx);
3448
3449 // Merge .riscv.attributes sections.
3450 if (ctx.arg.emachine == EM_RISCV)
3451 mergeRISCVAttributesSections(ctx);
3452
3453 {
3454 llvm::TimeTraceScope timeScope("Assign sections");
3455
3456 // Create output sections described by SECTIONS commands.
3457 ctx.script->processSectionCommands();
3458
3459 // Linker scripts control how input sections are assigned to output
3460 // sections. Input sections that were not handled by scripts are called
3461 // "orphans", and they are assigned to output sections by the default rule.
3462 // Process that.
3463 ctx.script->addOrphanSections();
3464 }
3465
3466 {
3467 llvm::TimeTraceScope timeScope("Merge/finalize input sections");
3468
3469 // Migrate InputSectionDescription::sectionBases to sections. This includes
3470 // merging MergeInputSections into a single MergeSyntheticSection. From this
3471 // point onwards InputSectionDescription::sections should be used instead of
3472 // sectionBases.
3473 for (SectionCommand *cmd : ctx.script->sectionCommands)
3474 if (auto *osd = dyn_cast<OutputDesc>(Val: cmd))
3475 osd->osec.finalizeInputSections();
3476 }
3477
3478 // Two input sections with different output sections should not be folded.
3479 // ICF runs after processSectionCommands() so that we know the output sections.
3480 if (ctx.arg.icf != ICFLevel::None) {
3481 findKeepUniqueSections<ELFT>(ctx, args);
3482 doIcf<ELFT>(ctx);
3483 }
3484
3485 // Read the callgraph now that we know what was gced or icfed
3486 if (ctx.arg.callGraphProfileSort != CGProfileSortKind::None) {
3487 if (auto *arg = args.getLastArg(Ids: OPT_call_graph_ordering_file)) {
3488 if (std::optional<MemoryBufferRef> buffer =
3489 readFile(ctx, path: arg->getValue()))
3490 readCallGraph(ctx, mb: *buffer);
3491 } else
3492 readCallGraphsFromObjectFiles<ELFT>(ctx);
3493 }
3494
3495 // Write the result to the file.
3496 writeResult<ELFT>(ctx);
3497}
3498