1 //===- DriverUtils.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 // This file contains utility functions for the driver. Because there
10 // are so many small functions, we created this separate file to make
11 // Driver.cpp less cluttered.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "COFFLinkerContext.h"
16 #include "Driver.h"
17 #include "Symbols.h"
18 #include "lld/Common/ErrorHandler.h"
19 #include "lld/Common/Memory.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/StringExtras.h"
22 #include "llvm/ADT/StringSwitch.h"
23 #include "llvm/BinaryFormat/COFF.h"
24 #include "llvm/Object/COFF.h"
25 #include "llvm/Object/WindowsResource.h"
26 #include "llvm/Option/Arg.h"
27 #include "llvm/Option/ArgList.h"
28 #include "llvm/Option/Option.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/FileUtilities.h"
31 #include "llvm/Support/MathExtras.h"
32 #include "llvm/Support/Process.h"
33 #include "llvm/Support/Program.h"
34 #include "llvm/Support/TimeProfiler.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/WindowsManifest/WindowsManifestMerger.h"
37 #include <limits>
38 #include <memory>
39 #include <optional>
40
41 using namespace llvm::COFF;
42 using namespace llvm::opt;
43 using namespace llvm;
44 using llvm::sys::Process;
45
46 namespace lld {
47 namespace coff {
48 namespace {
49
50 const uint16_t SUBLANG_ENGLISH_US = 0x0409;
51 const uint16_t RT_MANIFEST = 24;
52
53 class Executor {
54 public:
Executor(StringRef s)55 explicit Executor(StringRef s) : prog(saver().save(s)) {}
add(StringRef s)56 void add(StringRef s) { args.push_back(saver().save(s)); }
add(std::string & s)57 void add(std::string &s) { args.push_back(saver().save(s)); }
add(Twine s)58 void add(Twine s) { args.push_back(saver().save(s)); }
add(const char * s)59 void add(const char *s) { args.push_back(saver().save(s)); }
60
run()61 void run() {
62 ErrorOr<std::string> exeOrErr = sys::findProgramByName(prog);
63 if (auto ec = exeOrErr.getError())
64 fatal("unable to find " + prog + " in PATH: " + ec.message());
65 StringRef exe = saver().save(*exeOrErr);
66 args.insert(args.begin(), exe);
67
68 if (sys::ExecuteAndWait(args[0], args) != 0)
69 fatal("ExecuteAndWait failed: " +
70 llvm::join(args.begin(), args.end(), " "));
71 }
72
73 private:
74 StringRef prog;
75 std::vector<StringRef> args;
76 };
77
78 } // anonymous namespace
79
80 // Parses a string in the form of "<integer>[,<integer>]".
parseNumbers(StringRef arg,uint64_t * addr,uint64_t * size)81 void LinkerDriver::parseNumbers(StringRef arg, uint64_t *addr, uint64_t *size) {
82 auto [s1, s2] = arg.split(',');
83 if (s1.getAsInteger(0, *addr))
84 fatal("invalid number: " + s1);
85 if (size && !s2.empty() && s2.getAsInteger(0, *size))
86 fatal("invalid number: " + s2);
87 }
88
89 // Parses a string in the form of "<integer>[.<integer>]".
90 // If second number is not present, Minor is set to 0.
parseVersion(StringRef arg,uint32_t * major,uint32_t * minor)91 void LinkerDriver::parseVersion(StringRef arg, uint32_t *major,
92 uint32_t *minor) {
93 auto [s1, s2] = arg.split('.');
94 if (s1.getAsInteger(10, *major))
95 fatal("invalid number: " + s1);
96 *minor = 0;
97 if (!s2.empty() && s2.getAsInteger(10, *minor))
98 fatal("invalid number: " + s2);
99 }
100
parseGuard(StringRef fullArg)101 void LinkerDriver::parseGuard(StringRef fullArg) {
102 SmallVector<StringRef, 1> splitArgs;
103 fullArg.split(splitArgs, ",");
104 for (StringRef arg : splitArgs) {
105 if (arg.equals_insensitive("no"))
106 ctx.config.guardCF = GuardCFLevel::Off;
107 else if (arg.equals_insensitive("nolongjmp"))
108 ctx.config.guardCF &= ~GuardCFLevel::LongJmp;
109 else if (arg.equals_insensitive("noehcont"))
110 ctx.config.guardCF &= ~GuardCFLevel::EHCont;
111 else if (arg.equals_insensitive("cf") || arg.equals_insensitive("longjmp"))
112 ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::LongJmp;
113 else if (arg.equals_insensitive("ehcont"))
114 ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::EHCont;
115 else
116 fatal("invalid argument to /guard: " + arg);
117 }
118 }
119
120 // Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
parseSubsystem(StringRef arg,WindowsSubsystem * sys,uint32_t * major,uint32_t * minor,bool * gotVersion)121 void LinkerDriver::parseSubsystem(StringRef arg, WindowsSubsystem *sys,
122 uint32_t *major, uint32_t *minor,
123 bool *gotVersion) {
124 auto [sysStr, ver] = arg.split(',');
125 std::string sysStrLower = sysStr.lower();
126 *sys = StringSwitch<WindowsSubsystem>(sysStrLower)
127 .Case("boot_application", IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
128 .Case("console", IMAGE_SUBSYSTEM_WINDOWS_CUI)
129 .Case("default", IMAGE_SUBSYSTEM_UNKNOWN)
130 .Case("efi_application", IMAGE_SUBSYSTEM_EFI_APPLICATION)
131 .Case("efi_boot_service_driver", IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
132 .Case("efi_rom", IMAGE_SUBSYSTEM_EFI_ROM)
133 .Case("efi_runtime_driver", IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
134 .Case("native", IMAGE_SUBSYSTEM_NATIVE)
135 .Case("posix", IMAGE_SUBSYSTEM_POSIX_CUI)
136 .Case("windows", IMAGE_SUBSYSTEM_WINDOWS_GUI)
137 .Default(IMAGE_SUBSYSTEM_UNKNOWN);
138 if (*sys == IMAGE_SUBSYSTEM_UNKNOWN && sysStrLower != "default")
139 fatal("unknown subsystem: " + sysStr);
140 if (!ver.empty())
141 parseVersion(ver, major, minor);
142 if (gotVersion)
143 *gotVersion = !ver.empty();
144 }
145
146 // Parse a string of the form of "<from>=<to>".
147 // Results are directly written to Config.
parseAlternateName(StringRef s)148 void LinkerDriver::parseAlternateName(StringRef s) {
149 auto [from, to] = s.split('=');
150 if (from.empty() || to.empty())
151 fatal("/alternatename: invalid argument: " + s);
152 auto it = ctx.config.alternateNames.find(from);
153 if (it != ctx.config.alternateNames.end() && it->second != to)
154 fatal("/alternatename: conflicts: " + s);
155 ctx.config.alternateNames.insert(it, std::make_pair(from, to));
156 }
157
158 // Parse a string of the form of "<from>=<to>".
159 // Results are directly written to Config.
parseMerge(StringRef s)160 void LinkerDriver::parseMerge(StringRef s) {
161 auto [from, to] = s.split('=');
162 if (from.empty() || to.empty())
163 fatal("/merge: invalid argument: " + s);
164 if (from == ".rsrc" || to == ".rsrc")
165 fatal("/merge: cannot merge '.rsrc' with any section");
166 if (from == ".reloc" || to == ".reloc")
167 fatal("/merge: cannot merge '.reloc' with any section");
168 auto pair = ctx.config.merge.insert(std::make_pair(from, to));
169 bool inserted = pair.second;
170 if (!inserted) {
171 StringRef existing = pair.first->second;
172 if (existing != to)
173 warn(s + ": already merged into " + existing);
174 }
175 }
176
parsePDBPageSize(StringRef s)177 void LinkerDriver::parsePDBPageSize(StringRef s) {
178 int v;
179 if (s.getAsInteger(0, v)) {
180 error("/pdbpagesize: invalid argument: " + s);
181 return;
182 }
183 if (v != 4096 && v != 8192 && v != 16384 && v != 32768) {
184 error("/pdbpagesize: invalid argument: " + s);
185 return;
186 }
187
188 ctx.config.pdbPageSize = v;
189 }
190
parseSectionAttributes(StringRef s)191 static uint32_t parseSectionAttributes(StringRef s) {
192 uint32_t ret = 0;
193 for (char c : s.lower()) {
194 switch (c) {
195 case 'd':
196 ret |= IMAGE_SCN_MEM_DISCARDABLE;
197 break;
198 case 'e':
199 ret |= IMAGE_SCN_MEM_EXECUTE;
200 break;
201 case 'k':
202 ret |= IMAGE_SCN_MEM_NOT_CACHED;
203 break;
204 case 'p':
205 ret |= IMAGE_SCN_MEM_NOT_PAGED;
206 break;
207 case 'r':
208 ret |= IMAGE_SCN_MEM_READ;
209 break;
210 case 's':
211 ret |= IMAGE_SCN_MEM_SHARED;
212 break;
213 case 'w':
214 ret |= IMAGE_SCN_MEM_WRITE;
215 break;
216 default:
217 fatal("/section: invalid argument: " + s);
218 }
219 }
220 return ret;
221 }
222
223 // Parses /section option argument.
parseSection(StringRef s)224 void LinkerDriver::parseSection(StringRef s) {
225 auto [name, attrs] = s.split(',');
226 if (name.empty() || attrs.empty())
227 fatal("/section: invalid argument: " + s);
228 ctx.config.section[name] = parseSectionAttributes(attrs);
229 }
230
231 // Parses /aligncomm option argument.
parseAligncomm(StringRef s)232 void LinkerDriver::parseAligncomm(StringRef s) {
233 auto [name, align] = s.split(',');
234 if (name.empty() || align.empty()) {
235 error("/aligncomm: invalid argument: " + s);
236 return;
237 }
238 int v;
239 if (align.getAsInteger(0, v)) {
240 error("/aligncomm: invalid argument: " + s);
241 return;
242 }
243 ctx.config.alignComm[std::string(name)] =
244 std::max(ctx.config.alignComm[std::string(name)], 1 << v);
245 }
246
247 // Parses /functionpadmin option argument.
parseFunctionPadMin(llvm::opt::Arg * a)248 void LinkerDriver::parseFunctionPadMin(llvm::opt::Arg *a) {
249 StringRef arg = a->getNumValues() ? a->getValue() : "";
250 if (!arg.empty()) {
251 // Optional padding in bytes is given.
252 if (arg.getAsInteger(0, ctx.config.functionPadMin))
253 error("/functionpadmin: invalid argument: " + arg);
254 return;
255 }
256 // No optional argument given.
257 // Set default padding based on machine, similar to link.exe.
258 // There is no default padding for ARM platforms.
259 if (ctx.config.machine == I386) {
260 ctx.config.functionPadMin = 5;
261 } else if (ctx.config.machine == AMD64) {
262 ctx.config.functionPadMin = 6;
263 } else {
264 error("/functionpadmin: invalid argument for this machine: " + arg);
265 }
266 }
267
268 // Parses /dependentloadflag option argument.
parseDependentLoadFlags(llvm::opt::Arg * a)269 void LinkerDriver::parseDependentLoadFlags(llvm::opt::Arg *a) {
270 StringRef arg = a->getNumValues() ? a->getValue() : "";
271 if (!arg.empty()) {
272 if (arg.getAsInteger(0, ctx.config.dependentLoadFlags))
273 error("/dependentloadflag: invalid argument: " + arg);
274 return;
275 }
276 // MSVC linker reports error "no argument specified", although MSDN describes
277 // argument as optional.
278 error("/dependentloadflag: no argument specified");
279 }
280
281 // Parses a string in the form of "EMBED[,=<integer>]|NO".
282 // Results are directly written to
283 // Config.
parseManifest(StringRef arg)284 void LinkerDriver::parseManifest(StringRef arg) {
285 if (arg.equals_insensitive("no")) {
286 ctx.config.manifest = Configuration::No;
287 return;
288 }
289 if (!arg.starts_with_insensitive("embed"))
290 fatal("invalid option " + arg);
291 ctx.config.manifest = Configuration::Embed;
292 arg = arg.substr(strlen("embed"));
293 if (arg.empty())
294 return;
295 if (!arg.starts_with_insensitive(",id="))
296 fatal("invalid option " + arg);
297 arg = arg.substr(strlen(",id="));
298 if (arg.getAsInteger(0, ctx.config.manifestID))
299 fatal("invalid option " + arg);
300 }
301
302 // Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
303 // Results are directly written to Config.
parseManifestUAC(StringRef arg)304 void LinkerDriver::parseManifestUAC(StringRef arg) {
305 if (arg.equals_insensitive("no")) {
306 ctx.config.manifestUAC = false;
307 return;
308 }
309 for (;;) {
310 arg = arg.ltrim();
311 if (arg.empty())
312 return;
313 if (arg.consume_front_insensitive("level=")) {
314 std::tie(ctx.config.manifestLevel, arg) = arg.split(" ");
315 continue;
316 }
317 if (arg.consume_front_insensitive("uiaccess=")) {
318 std::tie(ctx.config.manifestUIAccess, arg) = arg.split(" ");
319 continue;
320 }
321 fatal("invalid option " + arg);
322 }
323 }
324
325 // Parses a string in the form of "cd|net[,(cd|net)]*"
326 // Results are directly written to Config.
parseSwaprun(StringRef arg)327 void LinkerDriver::parseSwaprun(StringRef arg) {
328 do {
329 auto [swaprun, newArg] = arg.split(',');
330 if (swaprun.equals_insensitive("cd"))
331 ctx.config.swaprunCD = true;
332 else if (swaprun.equals_insensitive("net"))
333 ctx.config.swaprunNet = true;
334 else if (swaprun.empty())
335 error("/swaprun: missing argument");
336 else
337 error("/swaprun: invalid argument: " + swaprun);
338 // To catch trailing commas, e.g. `/spawrun:cd,`
339 if (newArg.empty() && arg.ends_with(","))
340 error("/swaprun: missing argument");
341 arg = newArg;
342 } while (!arg.empty());
343 }
344
345 // An RAII temporary file class that automatically removes a temporary file.
346 namespace {
347 class TemporaryFile {
348 public:
TemporaryFile(StringRef prefix,StringRef extn,StringRef contents="")349 TemporaryFile(StringRef prefix, StringRef extn, StringRef contents = "") {
350 SmallString<128> s;
351 if (auto ec = sys::fs::createTemporaryFile("lld-" + prefix, extn, s))
352 fatal("cannot create a temporary file: " + ec.message());
353 path = std::string(s);
354
355 if (!contents.empty()) {
356 std::error_code ec;
357 raw_fd_ostream os(path, ec, sys::fs::OF_None);
358 if (ec)
359 fatal("failed to open " + path + ": " + ec.message());
360 os << contents;
361 }
362 }
363
TemporaryFile(TemporaryFile && obj)364 TemporaryFile(TemporaryFile &&obj) noexcept { std::swap(path, obj.path); }
365
~TemporaryFile()366 ~TemporaryFile() {
367 if (path.empty())
368 return;
369 if (sys::fs::remove(path))
370 fatal("failed to remove " + path);
371 }
372
373 // Returns a memory buffer of this temporary file.
374 // Note that this function does not leave the file open,
375 // so it is safe to remove the file immediately after this function
376 // is called (you cannot remove an opened file on Windows.)
getMemoryBuffer()377 std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
378 // IsVolatile=true forces MemoryBuffer to not use mmap().
379 return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
380 /*RequiresNullTerminator=*/false,
381 /*IsVolatile=*/true),
382 "could not open " + path);
383 }
384
385 std::string path;
386 };
387 }
388
createDefaultXml()389 std::string LinkerDriver::createDefaultXml() {
390 std::string ret;
391 raw_string_ostream os(ret);
392
393 // Emit the XML. Note that we do *not* verify that the XML attributes are
394 // syntactically correct. This is intentional for link.exe compatibility.
395 os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
396 << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
397 << " manifestVersion=\"1.0\">\n";
398 if (ctx.config.manifestUAC) {
399 os << " <trustInfo>\n"
400 << " <security>\n"
401 << " <requestedPrivileges>\n"
402 << " <requestedExecutionLevel level=" << ctx.config.manifestLevel
403 << " uiAccess=" << ctx.config.manifestUIAccess << "/>\n"
404 << " </requestedPrivileges>\n"
405 << " </security>\n"
406 << " </trustInfo>\n";
407 }
408 for (auto manifestDependency : ctx.config.manifestDependencies) {
409 os << " <dependency>\n"
410 << " <dependentAssembly>\n"
411 << " <assemblyIdentity " << manifestDependency << " />\n"
412 << " </dependentAssembly>\n"
413 << " </dependency>\n";
414 }
415 os << "</assembly>\n";
416 return os.str();
417 }
418
419 std::string
createManifestXmlWithInternalMt(StringRef defaultXml)420 LinkerDriver::createManifestXmlWithInternalMt(StringRef defaultXml) {
421 std::unique_ptr<MemoryBuffer> defaultXmlCopy =
422 MemoryBuffer::getMemBufferCopy(defaultXml);
423
424 windows_manifest::WindowsManifestMerger merger;
425 if (auto e = merger.merge(*defaultXmlCopy.get()))
426 fatal("internal manifest tool failed on default xml: " +
427 toString(std::move(e)));
428
429 for (StringRef filename : ctx.config.manifestInput) {
430 std::unique_ptr<MemoryBuffer> manifest =
431 check(MemoryBuffer::getFile(filename));
432 // Call takeBuffer to include in /reproduce: output if applicable.
433 if (auto e = merger.merge(takeBuffer(std::move(manifest))))
434 fatal("internal manifest tool failed on file " + filename + ": " +
435 toString(std::move(e)));
436 }
437
438 return std::string(merger.getMergedManifest().get()->getBuffer());
439 }
440
441 std::string
createManifestXmlWithExternalMt(StringRef defaultXml)442 LinkerDriver::createManifestXmlWithExternalMt(StringRef defaultXml) {
443 // Create the default manifest file as a temporary file.
444 TemporaryFile Default("defaultxml", "manifest");
445 std::error_code ec;
446 raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
447 if (ec)
448 fatal("failed to open " + Default.path + ": " + ec.message());
449 os << defaultXml;
450 os.close();
451
452 // Merge user-supplied manifests if they are given. Since libxml2 is not
453 // enabled, we must shell out to Microsoft's mt.exe tool.
454 TemporaryFile user("user", "manifest");
455
456 Executor e("mt.exe");
457 e.add("/manifest");
458 e.add(Default.path);
459 for (StringRef filename : ctx.config.manifestInput) {
460 e.add("/manifest");
461 e.add(filename);
462
463 // Manually add the file to the /reproduce: tar if needed.
464 if (tar)
465 if (auto mbOrErr = MemoryBuffer::getFile(filename))
466 takeBuffer(std::move(*mbOrErr));
467 }
468 e.add("/nologo");
469 e.add("/out:" + StringRef(user.path));
470 e.run();
471
472 return std::string(
473 CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
474 .get()
475 ->getBuffer());
476 }
477
createManifestXml()478 std::string LinkerDriver::createManifestXml() {
479 std::string defaultXml = createDefaultXml();
480 if (ctx.config.manifestInput.empty())
481 return defaultXml;
482
483 if (windows_manifest::isAvailable())
484 return createManifestXmlWithInternalMt(defaultXml);
485
486 return createManifestXmlWithExternalMt(defaultXml);
487 }
488
489 std::unique_ptr<WritableMemoryBuffer>
createMemoryBufferForManifestRes(size_t manifestSize)490 LinkerDriver::createMemoryBufferForManifestRes(size_t manifestSize) {
491 size_t resSize = alignTo(
492 object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
493 sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
494 sizeof(object::WinResHeaderSuffix) + manifestSize,
495 object::WIN_RES_DATA_ALIGNMENT);
496 return WritableMemoryBuffer::getNewMemBuffer(resSize, ctx.config.outputFile +
497 ".manifest.res");
498 }
499
writeResFileHeader(char * & buf)500 static void writeResFileHeader(char *&buf) {
501 memcpy(buf, COFF::WinResMagic, sizeof(COFF::WinResMagic));
502 buf += sizeof(COFF::WinResMagic);
503 memset(buf, 0, object::WIN_RES_NULL_ENTRY_SIZE);
504 buf += object::WIN_RES_NULL_ENTRY_SIZE;
505 }
506
writeResEntryHeader(char * & buf,size_t manifestSize,int manifestID)507 static void writeResEntryHeader(char *&buf, size_t manifestSize,
508 int manifestID) {
509 // Write the prefix.
510 auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
511 prefix->DataSize = manifestSize;
512 prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
513 sizeof(object::WinResIDs) +
514 sizeof(object::WinResHeaderSuffix);
515 buf += sizeof(object::WinResHeaderPrefix);
516
517 // Write the Type/Name IDs.
518 auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
519 iDs->setType(RT_MANIFEST);
520 iDs->setName(manifestID);
521 buf += sizeof(object::WinResIDs);
522
523 // Write the suffix.
524 auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
525 suffix->DataVersion = 0;
526 suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
527 suffix->Language = SUBLANG_ENGLISH_US;
528 suffix->Version = 0;
529 suffix->Characteristics = 0;
530 buf += sizeof(object::WinResHeaderSuffix);
531 }
532
533 // Create a resource file containing a manifest XML.
createManifestRes()534 std::unique_ptr<MemoryBuffer> LinkerDriver::createManifestRes() {
535 std::string manifest = createManifestXml();
536
537 std::unique_ptr<WritableMemoryBuffer> res =
538 createMemoryBufferForManifestRes(manifest.size());
539
540 char *buf = res->getBufferStart();
541 writeResFileHeader(buf);
542 writeResEntryHeader(buf, manifest.size(), ctx.config.manifestID);
543
544 // Copy the manifest data into the .res file.
545 std::copy(manifest.begin(), manifest.end(), buf);
546 return std::move(res);
547 }
548
createSideBySideManifest()549 void LinkerDriver::createSideBySideManifest() {
550 std::string path = std::string(ctx.config.manifestFile);
551 if (path == "")
552 path = ctx.config.outputFile + ".manifest";
553 std::error_code ec;
554 raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
555 if (ec)
556 fatal("failed to create manifest: " + ec.message());
557 out << createManifestXml();
558 }
559
560 // Parse a string in the form of
561 // "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
562 // or "<name>=<dllname>.<name>".
563 // Used for parsing /export arguments.
parseExport(StringRef arg)564 Export LinkerDriver::parseExport(StringRef arg) {
565 Export e;
566 e.source = ExportSource::Export;
567
568 StringRef rest;
569 std::tie(e.name, rest) = arg.split(",");
570 if (e.name.empty())
571 goto err;
572
573 if (e.name.contains('=')) {
574 auto [x, y] = e.name.split("=");
575
576 // If "<name>=<dllname>.<name>".
577 if (y.contains(".")) {
578 e.name = x;
579 e.forwardTo = y;
580 return e;
581 }
582
583 e.extName = x;
584 e.name = y;
585 if (e.name.empty())
586 goto err;
587 }
588
589 // If "<name>=<internalname>[,@ordinal[,NONAME]][,DATA][,PRIVATE]"
590 while (!rest.empty()) {
591 StringRef tok;
592 std::tie(tok, rest) = rest.split(",");
593 if (tok.equals_insensitive("noname")) {
594 if (e.ordinal == 0)
595 goto err;
596 e.noname = true;
597 continue;
598 }
599 if (tok.equals_insensitive("data")) {
600 e.data = true;
601 continue;
602 }
603 if (tok.equals_insensitive("constant")) {
604 e.constant = true;
605 continue;
606 }
607 if (tok.equals_insensitive("private")) {
608 e.isPrivate = true;
609 continue;
610 }
611 if (tok.starts_with("@")) {
612 int32_t ord;
613 if (tok.substr(1).getAsInteger(0, ord))
614 goto err;
615 if (ord <= 0 || 65535 < ord)
616 goto err;
617 e.ordinal = ord;
618 continue;
619 }
620 goto err;
621 }
622 return e;
623
624 err:
625 fatal("invalid /export: " + arg);
626 }
627
undecorate(COFFLinkerContext & ctx,StringRef sym)628 static StringRef undecorate(COFFLinkerContext &ctx, StringRef sym) {
629 if (ctx.config.machine != I386)
630 return sym;
631 // In MSVC mode, a fully decorated stdcall function is exported
632 // as-is with the leading underscore (with type IMPORT_NAME).
633 // In MinGW mode, a decorated stdcall function gets the underscore
634 // removed, just like normal cdecl functions.
635 if (sym.starts_with("_") && sym.contains('@') && !ctx.config.mingw)
636 return sym;
637 return sym.starts_with("_") ? sym.substr(1) : sym;
638 }
639
640 // Convert stdcall/fastcall style symbols into unsuffixed symbols,
641 // with or without a leading underscore. (MinGW specific.)
killAt(StringRef sym,bool prefix)642 static StringRef killAt(StringRef sym, bool prefix) {
643 if (sym.empty())
644 return sym;
645 // Strip any trailing stdcall suffix
646 sym = sym.substr(0, sym.find('@', 1));
647 if (!sym.starts_with("@")) {
648 if (prefix && !sym.starts_with("_"))
649 return saver().save("_" + sym);
650 return sym;
651 }
652 // For fastcall, remove the leading @ and replace it with an
653 // underscore, if prefixes are used.
654 sym = sym.substr(1);
655 if (prefix)
656 sym = saver().save("_" + sym);
657 return sym;
658 }
659
exportSourceName(ExportSource s)660 static StringRef exportSourceName(ExportSource s) {
661 switch (s) {
662 case ExportSource::Directives:
663 return "source file (directives)";
664 case ExportSource::Export:
665 return "/export";
666 case ExportSource::ModuleDefinition:
667 return "/def";
668 default:
669 llvm_unreachable("unknown ExportSource");
670 }
671 }
672
673 // Performs error checking on all /export arguments.
674 // It also sets ordinals.
fixupExports()675 void LinkerDriver::fixupExports() {
676 llvm::TimeTraceScope timeScope("Fixup exports");
677 // Symbol ordinals must be unique.
678 std::set<uint16_t> ords;
679 for (Export &e : ctx.config.exports) {
680 if (e.ordinal == 0)
681 continue;
682 if (!ords.insert(e.ordinal).second)
683 fatal("duplicate export ordinal: " + e.name);
684 }
685
686 for (Export &e : ctx.config.exports) {
687 if (!e.forwardTo.empty()) {
688 e.exportName = undecorate(ctx, e.name);
689 } else {
690 e.exportName = undecorate(ctx, e.extName.empty() ? e.name : e.extName);
691 }
692 }
693
694 if (ctx.config.killAt && ctx.config.machine == I386) {
695 for (Export &e : ctx.config.exports) {
696 e.name = killAt(e.name, true);
697 e.exportName = killAt(e.exportName, false);
698 e.extName = killAt(e.extName, true);
699 e.symbolName = killAt(e.symbolName, true);
700 }
701 }
702
703 // Uniquefy by name.
704 DenseMap<StringRef, std::pair<Export *, unsigned>> map(
705 ctx.config.exports.size());
706 std::vector<Export> v;
707 for (Export &e : ctx.config.exports) {
708 auto pair = map.insert(std::make_pair(e.exportName, std::make_pair(&e, 0)));
709 bool inserted = pair.second;
710 if (inserted) {
711 pair.first->second.second = v.size();
712 v.push_back(e);
713 continue;
714 }
715 Export *existing = pair.first->second.first;
716 if (e == *existing || e.name != existing->name)
717 continue;
718 // If the existing export comes from .OBJ directives, we are allowed to
719 // overwrite it with /DEF: or /EXPORT without any warning, as MSVC link.exe
720 // does.
721 if (existing->source == ExportSource::Directives) {
722 *existing = e;
723 v[pair.first->second.second] = e;
724 continue;
725 }
726 if (existing->source == e.source) {
727 warn(Twine("duplicate ") + exportSourceName(existing->source) +
728 " option: " + e.name);
729 } else {
730 warn("duplicate export: " + e.name +
731 Twine(" first seen in " + exportSourceName(existing->source) +
732 Twine(", now in " + exportSourceName(e.source))));
733 }
734 }
735 ctx.config.exports = std::move(v);
736
737 // Sort by name.
738 llvm::sort(ctx.config.exports, [](const Export &a, const Export &b) {
739 return a.exportName < b.exportName;
740 });
741 }
742
assignExportOrdinals()743 void LinkerDriver::assignExportOrdinals() {
744 // Assign unique ordinals if default (= 0).
745 uint32_t max = 0;
746 for (Export &e : ctx.config.exports)
747 max = std::max(max, (uint32_t)e.ordinal);
748 for (Export &e : ctx.config.exports)
749 if (e.ordinal == 0)
750 e.ordinal = ++max;
751 if (max > std::numeric_limits<uint16_t>::max())
752 fatal("too many exported symbols (got " + Twine(max) + ", max " +
753 Twine(std::numeric_limits<uint16_t>::max()) + ")");
754 }
755
756 // Parses a string in the form of "key=value" and check
757 // if value matches previous values for the same key.
checkFailIfMismatch(StringRef arg,InputFile * source)758 void LinkerDriver::checkFailIfMismatch(StringRef arg, InputFile *source) {
759 auto [k, v] = arg.split('=');
760 if (k.empty() || v.empty())
761 fatal("/failifmismatch: invalid argument: " + arg);
762 std::pair<StringRef, InputFile *> existing = ctx.config.mustMatch[k];
763 if (!existing.first.empty() && v != existing.first) {
764 std::string sourceStr = source ? toString(source) : "cmd-line";
765 std::string existingStr =
766 existing.second ? toString(existing.second) : "cmd-line";
767 fatal("/failifmismatch: mismatch detected for '" + k + "':\n>>> " +
768 existingStr + " has value " + existing.first + "\n>>> " + sourceStr +
769 " has value " + v);
770 }
771 ctx.config.mustMatch[k] = {v, source};
772 }
773
774 // Convert Windows resource files (.res files) to a .obj file.
775 // Does what cvtres.exe does, but in-process and cross-platform.
convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,ArrayRef<ObjFile * > objs)776 MemoryBufferRef LinkerDriver::convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
777 ArrayRef<ObjFile *> objs) {
778 object::WindowsResourceParser parser(/* MinGW */ ctx.config.mingw);
779
780 std::vector<std::string> duplicates;
781 for (MemoryBufferRef mb : mbs) {
782 std::unique_ptr<object::Binary> bin = check(object::createBinary(mb));
783 object::WindowsResource *rf = dyn_cast<object::WindowsResource>(bin.get());
784 if (!rf)
785 fatal("cannot compile non-resource file as resource");
786
787 if (auto ec = parser.parse(rf, duplicates))
788 fatal(toString(std::move(ec)));
789 }
790
791 // Note: This processes all .res files before all objs. Ideally they'd be
792 // handled in the same order they were linked (to keep the right one, if
793 // there are duplicates that are tolerated due to forceMultipleRes).
794 for (ObjFile *f : objs) {
795 object::ResourceSectionRef rsf;
796 if (auto ec = rsf.load(f->getCOFFObj()))
797 fatal(toString(f) + ": " + toString(std::move(ec)));
798
799 if (auto ec = parser.parse(rsf, f->getName(), duplicates))
800 fatal(toString(std::move(ec)));
801 }
802
803 if (ctx.config.mingw)
804 parser.cleanUpManifests(duplicates);
805
806 for (const auto &dupeDiag : duplicates)
807 if (ctx.config.forceMultipleRes)
808 warn(dupeDiag);
809 else
810 error(dupeDiag);
811
812 Expected<std::unique_ptr<MemoryBuffer>> e =
813 llvm::object::writeWindowsResourceCOFF(ctx.config.machine, parser,
814 ctx.config.timestamp);
815 if (!e)
816 fatal("failed to write .res to COFF: " + toString(e.takeError()));
817
818 MemoryBufferRef mbref = **e;
819 make<std::unique_ptr<MemoryBuffer>>(std::move(*e)); // take ownership
820 return mbref;
821 }
822
823 // Create OptTable
824
825 // Create prefix string literals used in Options.td
826 #define PREFIX(NAME, VALUE) \
827 static constexpr llvm::StringLiteral NAME##_init[] = VALUE; \
828 static constexpr llvm::ArrayRef<llvm::StringLiteral> NAME( \
829 NAME##_init, std::size(NAME##_init) - 1);
830 #include "Options.inc"
831 #undef PREFIX
832
833 // Create table mapping all options defined in Options.td
834 static constexpr llvm::opt::OptTable::Info infoTable[] = {
835 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
836 #include "Options.inc"
837 #undef OPTION
838 };
839
COFFOptTable()840 COFFOptTable::COFFOptTable() : GenericOptTable(infoTable, true) {}
841
842 // Set color diagnostics according to --color-diagnostics={auto,always,never}
843 // or --no-color-diagnostics flags.
handleColorDiagnostics(opt::InputArgList & args)844 static void handleColorDiagnostics(opt::InputArgList &args) {
845 auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
846 OPT_no_color_diagnostics);
847 if (!arg)
848 return;
849 if (arg->getOption().getID() == OPT_color_diagnostics) {
850 lld::errs().enable_colors(true);
851 } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
852 lld::errs().enable_colors(false);
853 } else {
854 StringRef s = arg->getValue();
855 if (s == "always")
856 lld::errs().enable_colors(true);
857 else if (s == "never")
858 lld::errs().enable_colors(false);
859 else if (s != "auto")
860 error("unknown option: --color-diagnostics=" + s);
861 }
862 }
863
getQuotingStyle(opt::InputArgList & args)864 static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
865 if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
866 StringRef s = arg->getValue();
867 if (s != "windows" && s != "posix")
868 error("invalid response file quoting: " + s);
869 if (s == "windows")
870 return cl::TokenizeWindowsCommandLine;
871 return cl::TokenizeGNUCommandLine;
872 }
873 // The COFF linker always defaults to Windows quoting.
874 return cl::TokenizeWindowsCommandLine;
875 }
876
ArgParser(COFFLinkerContext & c)877 ArgParser::ArgParser(COFFLinkerContext &c) : ctx(c) {}
878
879 // Parses a given list of options.
parse(ArrayRef<const char * > argv)880 opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
881 // Make InputArgList from string vectors.
882 unsigned missingIndex;
883 unsigned missingCount;
884
885 // We need to get the quoting style for response files before parsing all
886 // options so we parse here before and ignore all the options but
887 // --rsp-quoting and /lldignoreenv.
888 // (This means --rsp-quoting can't be added through %LINK%.)
889 opt::InputArgList args =
890 ctx.optTable.ParseArgs(argv, missingIndex, missingCount);
891
892 // Expand response files (arguments in the form of @<filename>) and insert
893 // flags from %LINK% and %_LINK_%, and then parse the argument again.
894 SmallVector<const char *, 256> expandedArgv(argv.data(),
895 argv.data() + argv.size());
896 if (!args.hasArg(OPT_lldignoreenv))
897 addLINK(expandedArgv);
898 cl::ExpandResponseFiles(saver(), getQuotingStyle(args), expandedArgv);
899 args = ctx.optTable.ParseArgs(ArrayRef(expandedArgv).drop_front(),
900 missingIndex, missingCount);
901
902 // Print the real command line if response files are expanded.
903 if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
904 std::string msg = "Command line:";
905 for (const char *s : expandedArgv)
906 msg += " " + std::string(s);
907 message(msg);
908 }
909
910 // Save the command line after response file expansion so we can write it to
911 // the PDB if necessary. Mimic MSVC, which skips input files.
912 ctx.config.argv = {argv[0]};
913 for (opt::Arg *arg : args) {
914 if (arg->getOption().getKind() != opt::Option::InputClass) {
915 ctx.config.argv.emplace_back(args.getArgString(arg->getIndex()));
916 }
917 }
918
919 // Handle /WX early since it converts missing argument warnings to errors.
920 errorHandler().fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
921
922 if (missingCount)
923 fatal(Twine(args.getArgString(missingIndex)) + ": missing argument");
924
925 handleColorDiagnostics(args);
926
927 for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
928 std::string nearest;
929 if (ctx.optTable.findNearest(arg->getAsString(args), nearest) > 1)
930 warn("ignoring unknown argument '" + arg->getAsString(args) + "'");
931 else
932 warn("ignoring unknown argument '" + arg->getAsString(args) +
933 "', did you mean '" + nearest + "'");
934 }
935
936 if (args.hasArg(OPT_lib))
937 warn("ignoring /lib since it's not the first argument");
938
939 return args;
940 }
941
942 // Tokenizes and parses a given string as command line in .drective section.
parseDirectives(StringRef s)943 ParsedDirectives ArgParser::parseDirectives(StringRef s) {
944 ParsedDirectives result;
945 SmallVector<const char *, 16> rest;
946
947 // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
948 // potentially every symbol in the object, so they must be handled quickly.
949 SmallVector<StringRef, 16> tokens;
950 cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
951 for (StringRef tok : tokens) {
952 if (tok.starts_with_insensitive("/export:") ||
953 tok.starts_with_insensitive("-export:"))
954 result.exports.push_back(tok.substr(strlen("/export:")));
955 else if (tok.starts_with_insensitive("/include:") ||
956 tok.starts_with_insensitive("-include:"))
957 result.includes.push_back(tok.substr(strlen("/include:")));
958 else if (tok.starts_with_insensitive("/exclude-symbols:") ||
959 tok.starts_with_insensitive("-exclude-symbols:"))
960 result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
961 else {
962 // Copy substrings that are not valid C strings. The tokenizer may have
963 // already copied quoted arguments for us, so those do not need to be
964 // copied again.
965 bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
966 rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
967 }
968 }
969
970 // Make InputArgList from unparsed string vectors.
971 unsigned missingIndex;
972 unsigned missingCount;
973
974 result.args = ctx.optTable.ParseArgs(rest, missingIndex, missingCount);
975
976 if (missingCount)
977 fatal(Twine(result.args.getArgString(missingIndex)) + ": missing argument");
978 for (auto *arg : result.args.filtered(OPT_UNKNOWN))
979 warn("ignoring unknown argument: " + arg->getAsString(result.args));
980 return result;
981 }
982
983 // link.exe has an interesting feature. If LINK or _LINK_ environment
984 // variables exist, their contents are handled as command line strings.
985 // So you can pass extra arguments using them.
addLINK(SmallVector<const char *,256> & argv)986 void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
987 // Concatenate LINK env and command line arguments, and then parse them.
988 if (std::optional<std::string> s = Process::GetEnv("LINK")) {
989 std::vector<const char *> v = tokenize(*s);
990 argv.insert(std::next(argv.begin()), v.begin(), v.end());
991 }
992 if (std::optional<std::string> s = Process::GetEnv("_LINK_")) {
993 std::vector<const char *> v = tokenize(*s);
994 argv.insert(std::next(argv.begin()), v.begin(), v.end());
995 }
996 }
997
tokenize(StringRef s)998 std::vector<const char *> ArgParser::tokenize(StringRef s) {
999 SmallVector<const char *, 16> tokens;
1000 cl::TokenizeWindowsCommandLine(s, saver(), tokens);
1001 return std::vector<const char *>(tokens.begin(), tokens.end());
1002 }
1003
printHelp(const char * argv0)1004 void LinkerDriver::printHelp(const char *argv0) {
1005 ctx.optTable.printHelp(lld::outs(),
1006 (std::string(argv0) + " [options] file...").c_str(),
1007 "LLVM Linker", false);
1008 }
1009
1010 } // namespace coff
1011 } // namespace lld
1012