xref: /llvm-project/lld/COFF/DriverUtils.cpp (revision 455b3d6df20c9bb50cdba66fd2f3202bc43eb4ac)
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/IR/Mangler.h"
25 #include "llvm/Object/COFF.h"
26 #include "llvm/Object/WindowsResource.h"
27 #include "llvm/Option/Arg.h"
28 #include "llvm/Option/ArgList.h"
29 #include "llvm/Option/Option.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/FileUtilities.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/Process.h"
34 #include "llvm/Support/Program.h"
35 #include "llvm/Support/TimeProfiler.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/WindowsManifest/WindowsManifestMerger.h"
38 #include <limits>
39 #include <memory>
40 #include <optional>
41 
42 using namespace llvm::COFF;
43 using namespace llvm::object;
44 using namespace llvm::opt;
45 using namespace llvm;
46 using llvm::sys::Process;
47 
48 namespace lld {
49 namespace coff {
50 namespace {
51 
52 const uint16_t SUBLANG_ENGLISH_US = 0x0409;
53 const uint16_t RT_MANIFEST = 24;
54 
55 class Executor {
56 public:
57   explicit Executor(StringRef s) : prog(saver().save(s)) {}
58   void add(StringRef s) { args.push_back(saver().save(s)); }
59   void add(std::string &s) { args.push_back(saver().save(s)); }
60   void add(Twine s) { args.push_back(saver().save(s)); }
61   void add(const char *s) { args.push_back(saver().save(s)); }
62 
63   void run() {
64     ErrorOr<std::string> exeOrErr = sys::findProgramByName(prog);
65     if (auto ec = exeOrErr.getError())
66       fatal("unable to find " + prog + " in PATH: " + ec.message());
67     StringRef exe = saver().save(*exeOrErr);
68     args.insert(args.begin(), exe);
69 
70     if (sys::ExecuteAndWait(args[0], args) != 0)
71       fatal("ExecuteAndWait failed: " +
72             llvm::join(args.begin(), args.end(), " "));
73   }
74 
75 private:
76   StringRef prog;
77   std::vector<StringRef> args;
78 };
79 
80 } // anonymous namespace
81 
82 // Parses a string in the form of "<integer>[,<integer>]".
83 void LinkerDriver::parseNumbers(StringRef arg, uint64_t *addr, uint64_t *size) {
84   auto [s1, s2] = arg.split(',');
85   if (s1.getAsInteger(0, *addr))
86     Fatal(ctx) << "invalid number: " << s1;
87   if (size && !s2.empty() && s2.getAsInteger(0, *size))
88     Fatal(ctx) << "invalid number: " << s2;
89 }
90 
91 // Parses a string in the form of "<integer>[.<integer>]".
92 // If second number is not present, Minor is set to 0.
93 void LinkerDriver::parseVersion(StringRef arg, uint32_t *major,
94                                 uint32_t *minor) {
95   auto [s1, s2] = arg.split('.');
96   if (s1.getAsInteger(10, *major))
97     Fatal(ctx) << "invalid number: " << s1;
98   *minor = 0;
99   if (!s2.empty() && s2.getAsInteger(10, *minor))
100     Fatal(ctx) << "invalid number: " << s2;
101 }
102 
103 void LinkerDriver::parseGuard(StringRef fullArg) {
104   SmallVector<StringRef, 1> splitArgs;
105   fullArg.split(splitArgs, ",");
106   for (StringRef arg : splitArgs) {
107     if (arg.equals_insensitive("no"))
108       ctx.config.guardCF = GuardCFLevel::Off;
109     else if (arg.equals_insensitive("nolongjmp"))
110       ctx.config.guardCF &= ~GuardCFLevel::LongJmp;
111     else if (arg.equals_insensitive("noehcont"))
112       ctx.config.guardCF &= ~GuardCFLevel::EHCont;
113     else if (arg.equals_insensitive("cf") || arg.equals_insensitive("longjmp"))
114       ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::LongJmp;
115     else if (arg.equals_insensitive("ehcont"))
116       ctx.config.guardCF |= GuardCFLevel::CF | GuardCFLevel::EHCont;
117     else
118       Fatal(ctx) << "invalid argument to /guard: " << arg;
119   }
120 }
121 
122 // Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
123 void LinkerDriver::parseSubsystem(StringRef arg, WindowsSubsystem *sys,
124                                   uint32_t *major, uint32_t *minor,
125                                   bool *gotVersion) {
126   auto [sysStr, ver] = arg.split(',');
127   std::string sysStrLower = sysStr.lower();
128   *sys = StringSwitch<WindowsSubsystem>(sysStrLower)
129     .Case("boot_application", IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
130     .Case("console", IMAGE_SUBSYSTEM_WINDOWS_CUI)
131     .Case("default", IMAGE_SUBSYSTEM_UNKNOWN)
132     .Case("efi_application", IMAGE_SUBSYSTEM_EFI_APPLICATION)
133     .Case("efi_boot_service_driver", IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
134     .Case("efi_rom", IMAGE_SUBSYSTEM_EFI_ROM)
135     .Case("efi_runtime_driver", IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
136     .Case("native", IMAGE_SUBSYSTEM_NATIVE)
137     .Case("posix", IMAGE_SUBSYSTEM_POSIX_CUI)
138     .Case("windows", IMAGE_SUBSYSTEM_WINDOWS_GUI)
139     .Default(IMAGE_SUBSYSTEM_UNKNOWN);
140   if (*sys == IMAGE_SUBSYSTEM_UNKNOWN && sysStrLower != "default")
141     Fatal(ctx) << "unknown subsystem: " << sysStr;
142   if (!ver.empty())
143     parseVersion(ver, major, minor);
144   if (gotVersion)
145     *gotVersion = !ver.empty();
146 }
147 
148 // Parse a string of the form of "<from>=<to>".
149 // Results are directly written to Config.
150 void LinkerDriver::parseAlternateName(StringRef s) {
151   auto [from, to] = s.split('=');
152   if (from.empty() || to.empty())
153     Fatal(ctx) << "/alternatename: invalid argument: " << s;
154   auto it = ctx.config.alternateNames.find(from);
155   if (it != ctx.config.alternateNames.end() && it->second != to)
156     Fatal(ctx) << "/alternatename: conflicts: " << s;
157   ctx.config.alternateNames.insert(it, std::make_pair(from, to));
158 }
159 
160 // Parse a string of the form of "<from>=<to>".
161 // Results are directly written to Config.
162 void LinkerDriver::parseMerge(StringRef s) {
163   auto [from, to] = s.split('=');
164   if (from.empty() || to.empty())
165     Fatal(ctx) << "/merge: invalid argument: " << s;
166   if (from == ".rsrc" || to == ".rsrc")
167     Fatal(ctx) << "/merge: cannot merge '.rsrc' with any section";
168   if (from == ".reloc" || to == ".reloc")
169     Fatal(ctx) << "/merge: cannot merge '.reloc' with any section";
170   auto pair = ctx.config.merge.insert(std::make_pair(from, to));
171   bool inserted = pair.second;
172   if (!inserted) {
173     StringRef existing = pair.first->second;
174     if (existing != to)
175       Warn(ctx) << s << ": already merged into " << existing;
176   }
177 }
178 
179 void LinkerDriver::parsePDBPageSize(StringRef s) {
180   int v;
181   if (s.getAsInteger(0, v)) {
182     Err(ctx) << "/pdbpagesize: invalid argument: " << s;
183     return;
184   }
185   if (v != 4096 && v != 8192 && v != 16384 && v != 32768) {
186     Err(ctx) << "/pdbpagesize: invalid argument: " << s;
187     return;
188   }
189 
190   ctx.config.pdbPageSize = v;
191 }
192 
193 static uint32_t parseSectionAttributes(COFFLinkerContext &ctx, StringRef s) {
194   uint32_t ret = 0;
195   for (char c : s.lower()) {
196     switch (c) {
197     case 'd':
198       ret |= IMAGE_SCN_MEM_DISCARDABLE;
199       break;
200     case 'e':
201       ret |= IMAGE_SCN_MEM_EXECUTE;
202       break;
203     case 'k':
204       ret |= IMAGE_SCN_MEM_NOT_CACHED;
205       break;
206     case 'p':
207       ret |= IMAGE_SCN_MEM_NOT_PAGED;
208       break;
209     case 'r':
210       ret |= IMAGE_SCN_MEM_READ;
211       break;
212     case 's':
213       ret |= IMAGE_SCN_MEM_SHARED;
214       break;
215     case 'w':
216       ret |= IMAGE_SCN_MEM_WRITE;
217       break;
218     default:
219       Fatal(ctx) << "/section: invalid argument: " << s;
220     }
221   }
222   return ret;
223 }
224 
225 // Parses /section option argument.
226 void LinkerDriver::parseSection(StringRef s) {
227   auto [name, attrs] = s.split(',');
228   if (name.empty() || attrs.empty())
229     Fatal(ctx) << "/section: invalid argument: " << s;
230   ctx.config.section[name] = parseSectionAttributes(ctx, attrs);
231 }
232 
233 // Parses /aligncomm option argument.
234 void LinkerDriver::parseAligncomm(StringRef s) {
235   auto [name, align] = s.split(',');
236   if (name.empty() || align.empty()) {
237     Err(ctx) << "/aligncomm: invalid argument: " << s;
238     return;
239   }
240   int v;
241   if (align.getAsInteger(0, v)) {
242     Err(ctx) << "/aligncomm: invalid argument: " << s;
243     return;
244   }
245   ctx.config.alignComm[std::string(name)] =
246       std::max(ctx.config.alignComm[std::string(name)], 1 << v);
247 }
248 
249 void LinkerDriver::parseDosStub(StringRef path) {
250   std::unique_ptr<MemoryBuffer> stub =
251       CHECK(MemoryBuffer::getFile(path), "could not open " + path);
252   size_t bufferSize = stub->getBufferSize();
253   const char *bufferStart = stub->getBufferStart();
254   // MS link.exe compatibility:
255   // 1. stub must be greater than or equal to 64 bytes
256   // 2. stub must start with a valid dos signature 'MZ'
257   if (bufferSize < 64)
258     Err(ctx) << "/stub: stub must be greater than or equal to 64 bytes: "
259              << path;
260   if (bufferStart[0] != 'M' || bufferStart[1] != 'Z')
261     Err(ctx) << "/stub: invalid DOS signature: " << path;
262   ctx.config.dosStub = std::move(stub);
263 }
264 
265 // Parses /functionpadmin option argument.
266 void LinkerDriver::parseFunctionPadMin(llvm::opt::Arg *a) {
267   StringRef arg = a->getNumValues() ? a->getValue() : "";
268   if (!arg.empty()) {
269     // Optional padding in bytes is given.
270     if (arg.getAsInteger(0, ctx.config.functionPadMin))
271       Err(ctx) << "/functionpadmin: invalid argument: " << arg;
272     return;
273   }
274   // No optional argument given.
275   // Set default padding based on machine, similar to link.exe.
276   // There is no default padding for ARM platforms.
277   if (ctx.config.machine == I386) {
278     ctx.config.functionPadMin = 5;
279   } else if (ctx.config.machine == AMD64) {
280     ctx.config.functionPadMin = 6;
281   } else {
282     Err(ctx) << "/functionpadmin: invalid argument for this machine: " << arg;
283   }
284 }
285 
286 // Parses /dependentloadflag option argument.
287 void LinkerDriver::parseDependentLoadFlags(llvm::opt::Arg *a) {
288   StringRef arg = a->getNumValues() ? a->getValue() : "";
289   if (!arg.empty()) {
290     if (arg.getAsInteger(0, ctx.config.dependentLoadFlags))
291       Err(ctx) << "/dependentloadflag: invalid argument: " << arg;
292     return;
293   }
294   // MSVC linker reports error "no argument specified", although MSDN describes
295   // argument as optional.
296   Err(ctx) << "/dependentloadflag: no argument specified";
297 }
298 
299 // Parses a string in the form of "EMBED[,=<integer>]|NO".
300 // Results are directly written to
301 // Config.
302 void LinkerDriver::parseManifest(StringRef arg) {
303   if (arg.equals_insensitive("no")) {
304     ctx.config.manifest = Configuration::No;
305     return;
306   }
307   if (!arg.starts_with_insensitive("embed"))
308     Fatal(ctx) << "invalid option " << arg;
309   ctx.config.manifest = Configuration::Embed;
310   arg = arg.substr(strlen("embed"));
311   if (arg.empty())
312     return;
313   if (!arg.starts_with_insensitive(",id="))
314     Fatal(ctx) << "invalid option " << arg;
315   arg = arg.substr(strlen(",id="));
316   if (arg.getAsInteger(0, ctx.config.manifestID))
317     Fatal(ctx) << "invalid option " << arg;
318 }
319 
320 // Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
321 // Results are directly written to Config.
322 void LinkerDriver::parseManifestUAC(StringRef arg) {
323   if (arg.equals_insensitive("no")) {
324     ctx.config.manifestUAC = false;
325     return;
326   }
327   for (;;) {
328     arg = arg.ltrim();
329     if (arg.empty())
330       return;
331     if (arg.consume_front_insensitive("level=")) {
332       std::tie(ctx.config.manifestLevel, arg) = arg.split(" ");
333       continue;
334     }
335     if (arg.consume_front_insensitive("uiaccess=")) {
336       std::tie(ctx.config.manifestUIAccess, arg) = arg.split(" ");
337       continue;
338     }
339     Fatal(ctx) << "invalid option " << arg;
340   }
341 }
342 
343 // Parses a string in the form of "cd|net[,(cd|net)]*"
344 // Results are directly written to Config.
345 void LinkerDriver::parseSwaprun(StringRef arg) {
346   do {
347     auto [swaprun, newArg] = arg.split(',');
348     if (swaprun.equals_insensitive("cd"))
349       ctx.config.swaprunCD = true;
350     else if (swaprun.equals_insensitive("net"))
351       ctx.config.swaprunNet = true;
352     else if (swaprun.empty())
353       Err(ctx) << "/swaprun: missing argument";
354     else
355       Err(ctx) << "/swaprun: invalid argument: " << swaprun;
356     // To catch trailing commas, e.g. `/spawrun:cd,`
357     if (newArg.empty() && arg.ends_with(","))
358       Err(ctx) << "/swaprun: missing argument";
359     arg = newArg;
360   } while (!arg.empty());
361 }
362 
363 // An RAII temporary file class that automatically removes a temporary file.
364 namespace {
365 class TemporaryFile {
366 public:
367   TemporaryFile(COFFLinkerContext &ctx, StringRef prefix, StringRef extn,
368                 StringRef contents = "")
369       : ctx(ctx) {
370     SmallString<128> s;
371     if (auto ec = sys::fs::createTemporaryFile("lld-" + prefix, extn, s))
372       Fatal(ctx) << "cannot create a temporary file: " << ec.message();
373     path = std::string(s);
374 
375     if (!contents.empty()) {
376       std::error_code ec;
377       raw_fd_ostream os(path, ec, sys::fs::OF_None);
378       if (ec)
379         Fatal(ctx) << "failed to open " << path << ": " << ec.message();
380       os << contents;
381     }
382   }
383 
384   TemporaryFile(TemporaryFile &&obj) noexcept : ctx(obj.ctx) {
385     std::swap(path, obj.path);
386   }
387 
388   ~TemporaryFile() {
389     if (path.empty())
390       return;
391     if (sys::fs::remove(path))
392       Fatal(ctx) << "failed to remove " << path;
393   }
394 
395   // Returns a memory buffer of this temporary file.
396   // Note that this function does not leave the file open,
397   // so it is safe to remove the file immediately after this function
398   // is called (you cannot remove an opened file on Windows.)
399   std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
400     // IsVolatile=true forces MemoryBuffer to not use mmap().
401     return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
402                                        /*RequiresNullTerminator=*/false,
403                                        /*IsVolatile=*/true),
404                  "could not open " + path);
405   }
406 
407   COFFLinkerContext &ctx;
408   std::string path;
409 };
410 }
411 
412 std::string LinkerDriver::createDefaultXml() {
413   std::string ret;
414   raw_string_ostream os(ret);
415 
416   // Emit the XML. Note that we do *not* verify that the XML attributes are
417   // syntactically correct. This is intentional for link.exe compatibility.
418   os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
419      << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
420      << "          manifestVersion=\"1.0\">\n";
421   if (ctx.config.manifestUAC) {
422     os << "  <trustInfo>\n"
423        << "    <security>\n"
424        << "      <requestedPrivileges>\n"
425        << "         <requestedExecutionLevel level=" << ctx.config.manifestLevel
426        << " uiAccess=" << ctx.config.manifestUIAccess << "/>\n"
427        << "      </requestedPrivileges>\n"
428        << "    </security>\n"
429        << "  </trustInfo>\n";
430   }
431   for (auto manifestDependency : ctx.config.manifestDependencies) {
432     os << "  <dependency>\n"
433        << "    <dependentAssembly>\n"
434        << "      <assemblyIdentity " << manifestDependency << " />\n"
435        << "    </dependentAssembly>\n"
436        << "  </dependency>\n";
437   }
438   os << "</assembly>\n";
439   return ret;
440 }
441 
442 std::string
443 LinkerDriver::createManifestXmlWithInternalMt(StringRef defaultXml) {
444   std::unique_ptr<MemoryBuffer> defaultXmlCopy =
445       MemoryBuffer::getMemBufferCopy(defaultXml);
446 
447   windows_manifest::WindowsManifestMerger merger;
448   if (auto e = merger.merge(*defaultXmlCopy.get()))
449     Fatal(ctx) << "internal manifest tool failed on default xml: "
450                << toString(std::move(e));
451 
452   for (StringRef filename : ctx.config.manifestInput) {
453     std::unique_ptr<MemoryBuffer> manifest =
454         check(MemoryBuffer::getFile(filename));
455     // Call takeBuffer to include in /reproduce: output if applicable.
456     if (auto e = merger.merge(takeBuffer(std::move(manifest))))
457       Fatal(ctx) << "internal manifest tool failed on file " << filename << ": "
458                  << toString(std::move(e));
459   }
460 
461   return std::string(merger.getMergedManifest().get()->getBuffer());
462 }
463 
464 std::string
465 LinkerDriver::createManifestXmlWithExternalMt(StringRef defaultXml) {
466   // Create the default manifest file as a temporary file.
467   TemporaryFile Default(ctx, "defaultxml", "manifest");
468   std::error_code ec;
469   raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
470   if (ec)
471     Fatal(ctx) << "failed to open " << Default.path << ": " << ec.message();
472   os << defaultXml;
473   os.close();
474 
475   // Merge user-supplied manifests if they are given.  Since libxml2 is not
476   // enabled, we must shell out to Microsoft's mt.exe tool.
477   TemporaryFile user(ctx, "user", "manifest");
478 
479   Executor e("mt.exe");
480   e.add("/manifest");
481   e.add(Default.path);
482   for (StringRef filename : ctx.config.manifestInput) {
483     e.add("/manifest");
484     e.add(filename);
485 
486     // Manually add the file to the /reproduce: tar if needed.
487     if (tar)
488       if (auto mbOrErr = MemoryBuffer::getFile(filename))
489         takeBuffer(std::move(*mbOrErr));
490   }
491   e.add("/nologo");
492   e.add("/out:" + StringRef(user.path));
493   e.run();
494 
495   return std::string(
496       CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
497           .get()
498           ->getBuffer());
499 }
500 
501 std::string LinkerDriver::createManifestXml() {
502   std::string defaultXml = createDefaultXml();
503   if (ctx.config.manifestInput.empty())
504     return defaultXml;
505 
506   if (windows_manifest::isAvailable())
507     return createManifestXmlWithInternalMt(defaultXml);
508 
509   return createManifestXmlWithExternalMt(defaultXml);
510 }
511 
512 std::unique_ptr<WritableMemoryBuffer>
513 LinkerDriver::createMemoryBufferForManifestRes(size_t manifestSize) {
514   size_t resSize = alignTo(
515       object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
516           sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
517           sizeof(object::WinResHeaderSuffix) + manifestSize,
518       object::WIN_RES_DATA_ALIGNMENT);
519   return WritableMemoryBuffer::getNewMemBuffer(resSize, ctx.config.outputFile +
520                                                             ".manifest.res");
521 }
522 
523 static void writeResFileHeader(char *&buf) {
524   memcpy(buf, COFF::WinResMagic, sizeof(COFF::WinResMagic));
525   buf += sizeof(COFF::WinResMagic);
526   memset(buf, 0, object::WIN_RES_NULL_ENTRY_SIZE);
527   buf += object::WIN_RES_NULL_ENTRY_SIZE;
528 }
529 
530 static void writeResEntryHeader(char *&buf, size_t manifestSize,
531                                 int manifestID) {
532   // Write the prefix.
533   auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
534   prefix->DataSize = manifestSize;
535   prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
536                        sizeof(object::WinResIDs) +
537                        sizeof(object::WinResHeaderSuffix);
538   buf += sizeof(object::WinResHeaderPrefix);
539 
540   // Write the Type/Name IDs.
541   auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
542   iDs->setType(RT_MANIFEST);
543   iDs->setName(manifestID);
544   buf += sizeof(object::WinResIDs);
545 
546   // Write the suffix.
547   auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
548   suffix->DataVersion = 0;
549   suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
550   suffix->Language = SUBLANG_ENGLISH_US;
551   suffix->Version = 0;
552   suffix->Characteristics = 0;
553   buf += sizeof(object::WinResHeaderSuffix);
554 }
555 
556 // Create a resource file containing a manifest XML.
557 std::unique_ptr<MemoryBuffer> LinkerDriver::createManifestRes() {
558   std::string manifest = createManifestXml();
559 
560   std::unique_ptr<WritableMemoryBuffer> res =
561       createMemoryBufferForManifestRes(manifest.size());
562 
563   char *buf = res->getBufferStart();
564   writeResFileHeader(buf);
565   writeResEntryHeader(buf, manifest.size(), ctx.config.manifestID);
566 
567   // Copy the manifest data into the .res file.
568   std::copy(manifest.begin(), manifest.end(), buf);
569   return std::move(res);
570 }
571 
572 void LinkerDriver::createSideBySideManifest() {
573   std::string path = std::string(ctx.config.manifestFile);
574   if (path == "")
575     path = ctx.config.outputFile + ".manifest";
576   std::error_code ec;
577   raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
578   if (ec)
579     Fatal(ctx) << "failed to create manifest: " << ec.message();
580   out << createManifestXml();
581 }
582 
583 // Parse a string in the form of
584 // "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
585 // or "<name>=<dllname>.<name>".
586 // Used for parsing /export arguments.
587 Export LinkerDriver::parseExport(StringRef arg) {
588   Export e;
589   e.source = ExportSource::Export;
590 
591   StringRef rest;
592   std::tie(e.name, rest) = arg.split(",");
593   if (e.name.empty())
594     goto err;
595 
596   if (e.name.contains('=')) {
597     auto [x, y] = e.name.split("=");
598 
599     // If "<name>=<dllname>.<name>".
600     if (y.contains(".")) {
601       e.name = x;
602       e.forwardTo = y;
603     } else {
604       e.extName = x;
605       e.name = y;
606       if (e.name.empty())
607         goto err;
608     }
609   }
610 
611   // Optional parameters
612   // "[,@ordinal[,NONAME]][,DATA][,PRIVATE][,EXPORTAS,exportname]"
613   while (!rest.empty()) {
614     StringRef tok;
615     std::tie(tok, rest) = rest.split(",");
616     if (tok.equals_insensitive("noname")) {
617       if (e.ordinal == 0)
618         goto err;
619       e.noname = true;
620       continue;
621     }
622     if (tok.equals_insensitive("data")) {
623       e.data = true;
624       continue;
625     }
626     if (tok.equals_insensitive("constant")) {
627       e.constant = true;
628       continue;
629     }
630     if (tok.equals_insensitive("private")) {
631       e.isPrivate = true;
632       continue;
633     }
634     if (tok.equals_insensitive("exportas")) {
635       if (!rest.empty() && !rest.contains(','))
636         e.exportAs = rest;
637       else
638         Err(ctx) << "invalid EXPORTAS value: " << rest;
639       break;
640     }
641     if (tok.starts_with("@")) {
642       int32_t ord;
643       if (tok.substr(1).getAsInteger(0, ord))
644         goto err;
645       if (ord <= 0 || 65535 < ord)
646         goto err;
647       e.ordinal = ord;
648       continue;
649     }
650     goto err;
651   }
652   return e;
653 
654 err:
655   Fatal(ctx) << "invalid /export: " << arg;
656   llvm_unreachable("");
657 }
658 
659 // Parses a string in the form of "key=value" and check
660 // if value matches previous values for the same key.
661 void LinkerDriver::checkFailIfMismatch(StringRef arg, InputFile *source) {
662   auto [k, v] = arg.split('=');
663   if (k.empty() || v.empty())
664     Fatal(ctx) << "/failifmismatch: invalid argument: " << arg;
665   std::pair<StringRef, InputFile *> existing = ctx.config.mustMatch[k];
666   if (!existing.first.empty() && v != existing.first) {
667     std::string sourceStr = source ? toString(source) : "cmd-line";
668     std::string existingStr =
669         existing.second ? toString(existing.second) : "cmd-line";
670     Fatal(ctx) << "/failifmismatch: mismatch detected for '" << k << "':\n>>> "
671                << existingStr << " has value " << existing.first << "\n>>> "
672                << sourceStr << " has value " << v;
673   }
674   ctx.config.mustMatch[k] = {v, source};
675 }
676 
677 // Convert Windows resource files (.res files) to a .obj file.
678 // Does what cvtres.exe does, but in-process and cross-platform.
679 MemoryBufferRef LinkerDriver::convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
680                                                ArrayRef<ObjFile *> objs) {
681   object::WindowsResourceParser parser(/* MinGW */ ctx.config.mingw);
682 
683   std::vector<std::string> duplicates;
684   for (MemoryBufferRef mb : mbs) {
685     std::unique_ptr<object::Binary> bin = check(object::createBinary(mb));
686     object::WindowsResource *rf = dyn_cast<object::WindowsResource>(bin.get());
687     if (!rf)
688       Fatal(ctx) << "cannot compile non-resource file as resource";
689 
690     if (auto ec = parser.parse(rf, duplicates))
691       Fatal(ctx) << toString(std::move(ec));
692   }
693 
694   // Note: This processes all .res files before all objs. Ideally they'd be
695   // handled in the same order they were linked (to keep the right one, if
696   // there are duplicates that are tolerated due to forceMultipleRes).
697   for (ObjFile *f : objs) {
698     object::ResourceSectionRef rsf;
699     if (auto ec = rsf.load(f->getCOFFObj()))
700       Fatal(ctx) << toString(f) << ": " << toString(std::move(ec));
701 
702     if (auto ec = parser.parse(rsf, f->getName(), duplicates))
703       Fatal(ctx) << toString(std::move(ec));
704   }
705 
706   if (ctx.config.mingw)
707     parser.cleanUpManifests(duplicates);
708 
709   for (const auto &dupeDiag : duplicates)
710     if (ctx.config.forceMultipleRes)
711       Warn(ctx) << dupeDiag;
712     else
713       Err(ctx) << dupeDiag;
714 
715   Expected<std::unique_ptr<MemoryBuffer>> e =
716       llvm::object::writeWindowsResourceCOFF(ctx.config.machine, parser,
717                                              ctx.config.timestamp);
718   if (!e)
719     Fatal(ctx) << "failed to write .res to COFF: " << toString(e.takeError());
720 
721   MemoryBufferRef mbref = **e;
722   make<std::unique_ptr<MemoryBuffer>>(std::move(*e)); // take ownership
723   return mbref;
724 }
725 
726 // Create OptTable
727 
728 #define OPTTABLE_STR_TABLE_CODE
729 #include "Options.inc"
730 #undef OPTTABLE_STR_TABLE_CODE
731 
732 // Create prefix string literals used in Options.td
733 #define OPTTABLE_PREFIXES_TABLE_CODE
734 #include "Options.inc"
735 #undef OPTTABLE_PREFIXES_TABLE_CODE
736 
737 // Create table mapping all options defined in Options.td
738 static constexpr llvm::opt::OptTable::Info infoTable[] = {
739 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
740 #include "Options.inc"
741 #undef OPTION
742 };
743 
744 COFFOptTable::COFFOptTable()
745     : GenericOptTable(OptionStrTable, OptionPrefixesTable, infoTable, true) {}
746 
747 // Set color diagnostics according to --color-diagnostics={auto,always,never}
748 // or --no-color-diagnostics flags.
749 static void handleColorDiagnostics(COFFLinkerContext &ctx,
750                                    opt::InputArgList &args) {
751   auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
752                               OPT_no_color_diagnostics);
753   if (!arg)
754     return;
755   if (arg->getOption().getID() == OPT_color_diagnostics) {
756     ctx.e.errs().enable_colors(true);
757   } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
758     ctx.e.errs().enable_colors(false);
759   } else {
760     StringRef s = arg->getValue();
761     if (s == "always")
762       ctx.e.errs().enable_colors(true);
763     else if (s == "never")
764       ctx.e.errs().enable_colors(false);
765     else if (s != "auto")
766       Err(ctx) << "unknown option: --color-diagnostics=" << s;
767   }
768 }
769 
770 static cl::TokenizerCallback getQuotingStyle(COFFLinkerContext &ctx,
771                                              opt::InputArgList &args) {
772   if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
773     StringRef s = arg->getValue();
774     if (s != "windows" && s != "posix")
775       Err(ctx) << "invalid response file quoting: " << s;
776     if (s == "windows")
777       return cl::TokenizeWindowsCommandLine;
778     return cl::TokenizeGNUCommandLine;
779   }
780   // The COFF linker always defaults to Windows quoting.
781   return cl::TokenizeWindowsCommandLine;
782 }
783 
784 ArgParser::ArgParser(COFFLinkerContext &c) : ctx(c) {}
785 
786 // Parses a given list of options.
787 opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
788   // Make InputArgList from string vectors.
789   unsigned missingIndex;
790   unsigned missingCount;
791 
792   // We need to get the quoting style for response files before parsing all
793   // options so we parse here before and ignore all the options but
794   // --rsp-quoting and /lldignoreenv.
795   // (This means --rsp-quoting can't be added through %LINK%.)
796   opt::InputArgList args =
797       ctx.optTable.ParseArgs(argv, missingIndex, missingCount);
798 
799   // Expand response files (arguments in the form of @<filename>) and insert
800   // flags from %LINK% and %_LINK_%, and then parse the argument again.
801   SmallVector<const char *, 256> expandedArgv(argv.data(),
802                                               argv.data() + argv.size());
803   if (!args.hasArg(OPT_lldignoreenv))
804     addLINK(expandedArgv);
805   cl::ExpandResponseFiles(saver(), getQuotingStyle(ctx, args), expandedArgv);
806   args = ctx.optTable.ParseArgs(ArrayRef(expandedArgv).drop_front(),
807                                 missingIndex, missingCount);
808 
809   // Print the real command line if response files are expanded.
810   if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
811     std::string msg = "Command line:";
812     for (const char *s : expandedArgv)
813       msg += " " + std::string(s);
814     Msg(ctx) << msg;
815   }
816 
817   // Save the command line after response file expansion so we can write it to
818   // the PDB if necessary. Mimic MSVC, which skips input files.
819   ctx.config.argv = {argv[0]};
820   for (opt::Arg *arg : args) {
821     if (arg->getOption().getKind() != opt::Option::InputClass) {
822       ctx.config.argv.emplace_back(args.getArgString(arg->getIndex()));
823     }
824   }
825 
826   // Handle /WX early since it converts missing argument warnings to errors.
827   ctx.e.fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
828 
829   if (missingCount)
830     Fatal(ctx) << args.getArgString(missingIndex) << ": missing argument";
831 
832   handleColorDiagnostics(ctx, args);
833 
834   for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
835     std::string nearest;
836     if (ctx.optTable.findNearest(arg->getAsString(args), nearest) > 1)
837       Warn(ctx) << "ignoring unknown argument '" << arg->getAsString(args)
838                 << "'";
839     else
840       Warn(ctx) << "ignoring unknown argument '" << arg->getAsString(args)
841                 << "', did you mean '" << nearest << "'";
842   }
843 
844   if (args.hasArg(OPT_lib))
845     Warn(ctx) << "ignoring /lib since it's not the first argument";
846 
847   return args;
848 }
849 
850 // Tokenizes and parses a given string as command line in .drective section.
851 ParsedDirectives ArgParser::parseDirectives(StringRef s) {
852   ParsedDirectives result;
853   SmallVector<const char *, 16> rest;
854 
855   // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
856   // potentially every symbol in the object, so they must be handled quickly.
857   SmallVector<StringRef, 16> tokens;
858   cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
859   for (StringRef tok : tokens) {
860     if (tok.starts_with_insensitive("/export:") ||
861         tok.starts_with_insensitive("-export:"))
862       result.exports.push_back(tok.substr(strlen("/export:")));
863     else if (tok.starts_with_insensitive("/include:") ||
864              tok.starts_with_insensitive("-include:"))
865       result.includes.push_back(tok.substr(strlen("/include:")));
866     else if (tok.starts_with_insensitive("/exclude-symbols:") ||
867              tok.starts_with_insensitive("-exclude-symbols:"))
868       result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
869     else {
870       // Copy substrings that are not valid C strings. The tokenizer may have
871       // already copied quoted arguments for us, so those do not need to be
872       // copied again.
873       bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
874       rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
875     }
876   }
877 
878   // Make InputArgList from unparsed string vectors.
879   unsigned missingIndex;
880   unsigned missingCount;
881 
882   result.args = ctx.optTable.ParseArgs(rest, missingIndex, missingCount);
883 
884   if (missingCount)
885     Fatal(ctx) << result.args.getArgString(missingIndex)
886                << ": missing argument";
887   for (auto *arg : result.args.filtered(OPT_UNKNOWN))
888     Warn(ctx) << "ignoring unknown argument: " << arg->getAsString(result.args);
889   return result;
890 }
891 
892 // link.exe has an interesting feature. If LINK or _LINK_ environment
893 // variables exist, their contents are handled as command line strings.
894 // So you can pass extra arguments using them.
895 void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
896   // Concatenate LINK env and command line arguments, and then parse them.
897   if (std::optional<std::string> s = Process::GetEnv("LINK")) {
898     std::vector<const char *> v = tokenize(*s);
899     argv.insert(std::next(argv.begin()), v.begin(), v.end());
900   }
901   if (std::optional<std::string> s = Process::GetEnv("_LINK_")) {
902     std::vector<const char *> v = tokenize(*s);
903     argv.insert(std::next(argv.begin()), v.begin(), v.end());
904   }
905 }
906 
907 std::vector<const char *> ArgParser::tokenize(StringRef s) {
908   SmallVector<const char *, 16> tokens;
909   cl::TokenizeWindowsCommandLine(s, saver(), tokens);
910   return std::vector<const char *>(tokens.begin(), tokens.end());
911 }
912 
913 void LinkerDriver::printHelp(const char *argv0) {
914   ctx.optTable.printHelp(ctx.e.outs(),
915                          (std::string(argv0) + " [options] file...").c_str(),
916                          "LLVM Linker", false);
917 }
918 
919 } // namespace coff
920 } // namespace lld
921