xref: /freebsd/contrib/llvm-project/lld/COFF/DriverUtils.cpp (revision b1879975794772ee51f0b4865753364c7d7626c3)
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("invalid number: " + s1);
87   if (size && !s2.empty() && s2.getAsInteger(0, *size))
88     fatal("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("invalid number: " + s1);
98   *minor = 0;
99   if (!s2.empty() && s2.getAsInteger(10, *minor))
100     fatal("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("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("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("/alternatename: invalid argument: " + s);
154   auto it = ctx.config.alternateNames.find(from);
155   if (it != ctx.config.alternateNames.end() && it->second != to)
156     fatal("/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("/merge: invalid argument: " + s);
166   if (from == ".rsrc" || to == ".rsrc")
167     fatal("/merge: cannot merge '.rsrc' with any section");
168   if (from == ".reloc" || to == ".reloc")
169     fatal("/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(s + ": already merged into " + existing);
176   }
177 }
178 
179 void LinkerDriver::parsePDBPageSize(StringRef s) {
180   int v;
181   if (s.getAsInteger(0, v)) {
182     error("/pdbpagesize: invalid argument: " + s);
183     return;
184   }
185   if (v != 4096 && v != 8192 && v != 16384 && v != 32768) {
186     error("/pdbpagesize: invalid argument: " + s);
187     return;
188   }
189 
190   ctx.config.pdbPageSize = v;
191 }
192 
193 static uint32_t parseSectionAttributes(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("/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("/section: invalid argument: " + s);
230   ctx.config.section[name] = parseSectionAttributes(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     error("/aligncomm: invalid argument: " + s);
238     return;
239   }
240   int v;
241   if (align.getAsInteger(0, v)) {
242     error("/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 // Parses /functionpadmin option argument.
250 void LinkerDriver::parseFunctionPadMin(llvm::opt::Arg *a) {
251   StringRef arg = a->getNumValues() ? a->getValue() : "";
252   if (!arg.empty()) {
253     // Optional padding in bytes is given.
254     if (arg.getAsInteger(0, ctx.config.functionPadMin))
255       error("/functionpadmin: invalid argument: " + arg);
256     return;
257   }
258   // No optional argument given.
259   // Set default padding based on machine, similar to link.exe.
260   // There is no default padding for ARM platforms.
261   if (ctx.config.machine == I386) {
262     ctx.config.functionPadMin = 5;
263   } else if (ctx.config.machine == AMD64) {
264     ctx.config.functionPadMin = 6;
265   } else {
266     error("/functionpadmin: invalid argument for this machine: " + arg);
267   }
268 }
269 
270 // Parses /dependentloadflag option argument.
271 void LinkerDriver::parseDependentLoadFlags(llvm::opt::Arg *a) {
272   StringRef arg = a->getNumValues() ? a->getValue() : "";
273   if (!arg.empty()) {
274     if (arg.getAsInteger(0, ctx.config.dependentLoadFlags))
275       error("/dependentloadflag: invalid argument: " + arg);
276     return;
277   }
278   // MSVC linker reports error "no argument specified", although MSDN describes
279   // argument as optional.
280   error("/dependentloadflag: no argument specified");
281 }
282 
283 // Parses a string in the form of "EMBED[,=<integer>]|NO".
284 // Results are directly written to
285 // Config.
286 void LinkerDriver::parseManifest(StringRef arg) {
287   if (arg.equals_insensitive("no")) {
288     ctx.config.manifest = Configuration::No;
289     return;
290   }
291   if (!arg.starts_with_insensitive("embed"))
292     fatal("invalid option " + arg);
293   ctx.config.manifest = Configuration::Embed;
294   arg = arg.substr(strlen("embed"));
295   if (arg.empty())
296     return;
297   if (!arg.starts_with_insensitive(",id="))
298     fatal("invalid option " + arg);
299   arg = arg.substr(strlen(",id="));
300   if (arg.getAsInteger(0, ctx.config.manifestID))
301     fatal("invalid option " + arg);
302 }
303 
304 // Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
305 // Results are directly written to Config.
306 void LinkerDriver::parseManifestUAC(StringRef arg) {
307   if (arg.equals_insensitive("no")) {
308     ctx.config.manifestUAC = false;
309     return;
310   }
311   for (;;) {
312     arg = arg.ltrim();
313     if (arg.empty())
314       return;
315     if (arg.consume_front_insensitive("level=")) {
316       std::tie(ctx.config.manifestLevel, arg) = arg.split(" ");
317       continue;
318     }
319     if (arg.consume_front_insensitive("uiaccess=")) {
320       std::tie(ctx.config.manifestUIAccess, arg) = arg.split(" ");
321       continue;
322     }
323     fatal("invalid option " + arg);
324   }
325 }
326 
327 // Parses a string in the form of "cd|net[,(cd|net)]*"
328 // Results are directly written to Config.
329 void LinkerDriver::parseSwaprun(StringRef arg) {
330   do {
331     auto [swaprun, newArg] = arg.split(',');
332     if (swaprun.equals_insensitive("cd"))
333       ctx.config.swaprunCD = true;
334     else if (swaprun.equals_insensitive("net"))
335       ctx.config.swaprunNet = true;
336     else if (swaprun.empty())
337       error("/swaprun: missing argument");
338     else
339       error("/swaprun: invalid argument: " + swaprun);
340     // To catch trailing commas, e.g. `/spawrun:cd,`
341     if (newArg.empty() && arg.ends_with(","))
342       error("/swaprun: missing argument");
343     arg = newArg;
344   } while (!arg.empty());
345 }
346 
347 // An RAII temporary file class that automatically removes a temporary file.
348 namespace {
349 class TemporaryFile {
350 public:
351   TemporaryFile(StringRef prefix, StringRef extn, StringRef contents = "") {
352     SmallString<128> s;
353     if (auto ec = sys::fs::createTemporaryFile("lld-" + prefix, extn, s))
354       fatal("cannot create a temporary file: " + ec.message());
355     path = std::string(s);
356 
357     if (!contents.empty()) {
358       std::error_code ec;
359       raw_fd_ostream os(path, ec, sys::fs::OF_None);
360       if (ec)
361         fatal("failed to open " + path + ": " + ec.message());
362       os << contents;
363     }
364   }
365 
366   TemporaryFile(TemporaryFile &&obj) noexcept { std::swap(path, obj.path); }
367 
368   ~TemporaryFile() {
369     if (path.empty())
370       return;
371     if (sys::fs::remove(path))
372       fatal("failed to remove " + path);
373   }
374 
375   // Returns a memory buffer of this temporary file.
376   // Note that this function does not leave the file open,
377   // so it is safe to remove the file immediately after this function
378   // is called (you cannot remove an opened file on Windows.)
379   std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
380     // IsVolatile=true forces MemoryBuffer to not use mmap().
381     return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
382                                        /*RequiresNullTerminator=*/false,
383                                        /*IsVolatile=*/true),
384                  "could not open " + path);
385   }
386 
387   std::string path;
388 };
389 }
390 
391 std::string LinkerDriver::createDefaultXml() {
392   std::string ret;
393   raw_string_ostream os(ret);
394 
395   // Emit the XML. Note that we do *not* verify that the XML attributes are
396   // syntactically correct. This is intentional for link.exe compatibility.
397   os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
398      << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
399      << "          manifestVersion=\"1.0\">\n";
400   if (ctx.config.manifestUAC) {
401     os << "  <trustInfo>\n"
402        << "    <security>\n"
403        << "      <requestedPrivileges>\n"
404        << "         <requestedExecutionLevel level=" << ctx.config.manifestLevel
405        << " uiAccess=" << ctx.config.manifestUIAccess << "/>\n"
406        << "      </requestedPrivileges>\n"
407        << "    </security>\n"
408        << "  </trustInfo>\n";
409   }
410   for (auto manifestDependency : ctx.config.manifestDependencies) {
411     os << "  <dependency>\n"
412        << "    <dependentAssembly>\n"
413        << "      <assemblyIdentity " << manifestDependency << " />\n"
414        << "    </dependentAssembly>\n"
415        << "  </dependency>\n";
416   }
417   os << "</assembly>\n";
418   return os.str();
419 }
420 
421 std::string
422 LinkerDriver::createManifestXmlWithInternalMt(StringRef defaultXml) {
423   std::unique_ptr<MemoryBuffer> defaultXmlCopy =
424       MemoryBuffer::getMemBufferCopy(defaultXml);
425 
426   windows_manifest::WindowsManifestMerger merger;
427   if (auto e = merger.merge(*defaultXmlCopy.get()))
428     fatal("internal manifest tool failed on default xml: " +
429           toString(std::move(e)));
430 
431   for (StringRef filename : ctx.config.manifestInput) {
432     std::unique_ptr<MemoryBuffer> manifest =
433         check(MemoryBuffer::getFile(filename));
434     // Call takeBuffer to include in /reproduce: output if applicable.
435     if (auto e = merger.merge(takeBuffer(std::move(manifest))))
436       fatal("internal manifest tool failed on file " + filename + ": " +
437             toString(std::move(e)));
438   }
439 
440   return std::string(merger.getMergedManifest().get()->getBuffer());
441 }
442 
443 std::string
444 LinkerDriver::createManifestXmlWithExternalMt(StringRef defaultXml) {
445   // Create the default manifest file as a temporary file.
446   TemporaryFile Default("defaultxml", "manifest");
447   std::error_code ec;
448   raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
449   if (ec)
450     fatal("failed to open " + Default.path + ": " + ec.message());
451   os << defaultXml;
452   os.close();
453 
454   // Merge user-supplied manifests if they are given.  Since libxml2 is not
455   // enabled, we must shell out to Microsoft's mt.exe tool.
456   TemporaryFile user("user", "manifest");
457 
458   Executor e("mt.exe");
459   e.add("/manifest");
460   e.add(Default.path);
461   for (StringRef filename : ctx.config.manifestInput) {
462     e.add("/manifest");
463     e.add(filename);
464 
465     // Manually add the file to the /reproduce: tar if needed.
466     if (tar)
467       if (auto mbOrErr = MemoryBuffer::getFile(filename))
468         takeBuffer(std::move(*mbOrErr));
469   }
470   e.add("/nologo");
471   e.add("/out:" + StringRef(user.path));
472   e.run();
473 
474   return std::string(
475       CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
476           .get()
477           ->getBuffer());
478 }
479 
480 std::string LinkerDriver::createManifestXml() {
481   std::string defaultXml = createDefaultXml();
482   if (ctx.config.manifestInput.empty())
483     return defaultXml;
484 
485   if (windows_manifest::isAvailable())
486     return createManifestXmlWithInternalMt(defaultXml);
487 
488   return createManifestXmlWithExternalMt(defaultXml);
489 }
490 
491 std::unique_ptr<WritableMemoryBuffer>
492 LinkerDriver::createMemoryBufferForManifestRes(size_t manifestSize) {
493   size_t resSize = alignTo(
494       object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
495           sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
496           sizeof(object::WinResHeaderSuffix) + manifestSize,
497       object::WIN_RES_DATA_ALIGNMENT);
498   return WritableMemoryBuffer::getNewMemBuffer(resSize, ctx.config.outputFile +
499                                                             ".manifest.res");
500 }
501 
502 static void writeResFileHeader(char *&buf) {
503   memcpy(buf, COFF::WinResMagic, sizeof(COFF::WinResMagic));
504   buf += sizeof(COFF::WinResMagic);
505   memset(buf, 0, object::WIN_RES_NULL_ENTRY_SIZE);
506   buf += object::WIN_RES_NULL_ENTRY_SIZE;
507 }
508 
509 static void writeResEntryHeader(char *&buf, size_t manifestSize,
510                                 int manifestID) {
511   // Write the prefix.
512   auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
513   prefix->DataSize = manifestSize;
514   prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
515                        sizeof(object::WinResIDs) +
516                        sizeof(object::WinResHeaderSuffix);
517   buf += sizeof(object::WinResHeaderPrefix);
518 
519   // Write the Type/Name IDs.
520   auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
521   iDs->setType(RT_MANIFEST);
522   iDs->setName(manifestID);
523   buf += sizeof(object::WinResIDs);
524 
525   // Write the suffix.
526   auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
527   suffix->DataVersion = 0;
528   suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
529   suffix->Language = SUBLANG_ENGLISH_US;
530   suffix->Version = 0;
531   suffix->Characteristics = 0;
532   buf += sizeof(object::WinResHeaderSuffix);
533 }
534 
535 // Create a resource file containing a manifest XML.
536 std::unique_ptr<MemoryBuffer> LinkerDriver::createManifestRes() {
537   std::string manifest = createManifestXml();
538 
539   std::unique_ptr<WritableMemoryBuffer> res =
540       createMemoryBufferForManifestRes(manifest.size());
541 
542   char *buf = res->getBufferStart();
543   writeResFileHeader(buf);
544   writeResEntryHeader(buf, manifest.size(), ctx.config.manifestID);
545 
546   // Copy the manifest data into the .res file.
547   std::copy(manifest.begin(), manifest.end(), buf);
548   return std::move(res);
549 }
550 
551 void LinkerDriver::createSideBySideManifest() {
552   std::string path = std::string(ctx.config.manifestFile);
553   if (path == "")
554     path = ctx.config.outputFile + ".manifest";
555   std::error_code ec;
556   raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
557   if (ec)
558     fatal("failed to create manifest: " + ec.message());
559   out << createManifestXml();
560 }
561 
562 // Parse a string in the form of
563 // "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
564 // or "<name>=<dllname>.<name>".
565 // Used for parsing /export arguments.
566 Export LinkerDriver::parseExport(StringRef arg) {
567   Export e;
568   e.source = ExportSource::Export;
569 
570   StringRef rest;
571   std::tie(e.name, rest) = arg.split(",");
572   if (e.name.empty())
573     goto err;
574 
575   if (e.name.contains('=')) {
576     auto [x, y] = e.name.split("=");
577 
578     // If "<name>=<dllname>.<name>".
579     if (y.contains(".")) {
580       e.name = x;
581       e.forwardTo = y;
582     } else {
583       e.extName = x;
584       e.name = y;
585       if (e.name.empty())
586         goto err;
587     }
588   }
589 
590   // Optional parameters
591   // "[,@ordinal[,NONAME]][,DATA][,PRIVATE][,EXPORTAS,exportname]"
592   while (!rest.empty()) {
593     StringRef tok;
594     std::tie(tok, rest) = rest.split(",");
595     if (tok.equals_insensitive("noname")) {
596       if (e.ordinal == 0)
597         goto err;
598       e.noname = true;
599       continue;
600     }
601     if (tok.equals_insensitive("data")) {
602       e.data = true;
603       continue;
604     }
605     if (tok.equals_insensitive("constant")) {
606       e.constant = true;
607       continue;
608     }
609     if (tok.equals_insensitive("private")) {
610       e.isPrivate = true;
611       continue;
612     }
613     if (tok.equals_insensitive("exportas")) {
614       if (!rest.empty() && !rest.contains(','))
615         e.exportAs = rest;
616       else
617         error("invalid EXPORTAS value: " + rest);
618       break;
619     }
620     if (tok.starts_with("@")) {
621       int32_t ord;
622       if (tok.substr(1).getAsInteger(0, ord))
623         goto err;
624       if (ord <= 0 || 65535 < ord)
625         goto err;
626       e.ordinal = ord;
627       continue;
628     }
629     goto err;
630   }
631   return e;
632 
633 err:
634   fatal("invalid /export: " + arg);
635 }
636 
637 // Convert stdcall/fastcall style symbols into unsuffixed symbols,
638 // with or without a leading underscore. (MinGW specific.)
639 static StringRef killAt(StringRef sym, bool prefix) {
640   if (sym.empty())
641     return sym;
642   // Strip any trailing stdcall suffix
643   sym = sym.substr(0, sym.find('@', 1));
644   if (!sym.starts_with("@")) {
645     if (prefix && !sym.starts_with("_"))
646       return saver().save("_" + sym);
647     return sym;
648   }
649   // For fastcall, remove the leading @ and replace it with an
650   // underscore, if prefixes are used.
651   sym = sym.substr(1);
652   if (prefix)
653     sym = saver().save("_" + sym);
654   return sym;
655 }
656 
657 static StringRef exportSourceName(ExportSource s) {
658   switch (s) {
659   case ExportSource::Directives:
660     return "source file (directives)";
661   case ExportSource::Export:
662     return "/export";
663   case ExportSource::ModuleDefinition:
664     return "/def";
665   default:
666     llvm_unreachable("unknown ExportSource");
667   }
668 }
669 
670 // Performs error checking on all /export arguments.
671 // It also sets ordinals.
672 void LinkerDriver::fixupExports() {
673   llvm::TimeTraceScope timeScope("Fixup exports");
674   // Symbol ordinals must be unique.
675   std::set<uint16_t> ords;
676   for (Export &e : ctx.config.exports) {
677     if (e.ordinal == 0)
678       continue;
679     if (!ords.insert(e.ordinal).second)
680       fatal("duplicate export ordinal: " + e.name);
681   }
682 
683   for (Export &e : ctx.config.exports) {
684     if (!e.exportAs.empty()) {
685       e.exportName = e.exportAs;
686       continue;
687     }
688 
689     StringRef sym =
690         !e.forwardTo.empty() || e.extName.empty() ? e.name : e.extName;
691     if (ctx.config.machine == I386 && sym.starts_with("_")) {
692       // In MSVC mode, a fully decorated stdcall function is exported
693       // as-is with the leading underscore (with type IMPORT_NAME).
694       // In MinGW mode, a decorated stdcall function gets the underscore
695       // removed, just like normal cdecl functions.
696       if (ctx.config.mingw || !sym.contains('@')) {
697         e.exportName = sym.substr(1);
698         continue;
699       }
700     }
701     if (isArm64EC(ctx.config.machine) && !e.data && !e.constant) {
702       if (std::optional<std::string> demangledName =
703               getArm64ECDemangledFunctionName(sym)) {
704         e.exportName = saver().save(*demangledName);
705         continue;
706       }
707     }
708     e.exportName = sym;
709   }
710 
711   if (ctx.config.killAt && ctx.config.machine == I386) {
712     for (Export &e : ctx.config.exports) {
713       e.name = killAt(e.name, true);
714       e.exportName = killAt(e.exportName, false);
715       e.extName = killAt(e.extName, true);
716       e.symbolName = killAt(e.symbolName, true);
717     }
718   }
719 
720   // Uniquefy by name.
721   DenseMap<StringRef, std::pair<Export *, unsigned>> map(
722       ctx.config.exports.size());
723   std::vector<Export> v;
724   for (Export &e : ctx.config.exports) {
725     auto pair = map.insert(std::make_pair(e.exportName, std::make_pair(&e, 0)));
726     bool inserted = pair.second;
727     if (inserted) {
728       pair.first->second.second = v.size();
729       v.push_back(e);
730       continue;
731     }
732     Export *existing = pair.first->second.first;
733     if (e == *existing || e.name != existing->name)
734       continue;
735     // If the existing export comes from .OBJ directives, we are allowed to
736     // overwrite it with /DEF: or /EXPORT without any warning, as MSVC link.exe
737     // does.
738     if (existing->source == ExportSource::Directives) {
739       *existing = e;
740       v[pair.first->second.second] = e;
741       continue;
742     }
743     if (existing->source == e.source) {
744       warn(Twine("duplicate ") + exportSourceName(existing->source) +
745            " option: " + e.name);
746     } else {
747       warn("duplicate export: " + e.name +
748            Twine(" first seen in " + exportSourceName(existing->source) +
749                  Twine(", now in " + exportSourceName(e.source))));
750     }
751   }
752   ctx.config.exports = std::move(v);
753 
754   // Sort by name.
755   llvm::sort(ctx.config.exports, [](const Export &a, const Export &b) {
756     return a.exportName < b.exportName;
757   });
758 }
759 
760 void LinkerDriver::assignExportOrdinals() {
761   // Assign unique ordinals if default (= 0).
762   uint32_t max = 0;
763   for (Export &e : ctx.config.exports)
764     max = std::max(max, (uint32_t)e.ordinal);
765   for (Export &e : ctx.config.exports)
766     if (e.ordinal == 0)
767       e.ordinal = ++max;
768   if (max > std::numeric_limits<uint16_t>::max())
769     fatal("too many exported symbols (got " + Twine(max) + ", max " +
770           Twine(std::numeric_limits<uint16_t>::max()) + ")");
771 }
772 
773 // Parses a string in the form of "key=value" and check
774 // if value matches previous values for the same key.
775 void LinkerDriver::checkFailIfMismatch(StringRef arg, InputFile *source) {
776   auto [k, v] = arg.split('=');
777   if (k.empty() || v.empty())
778     fatal("/failifmismatch: invalid argument: " + arg);
779   std::pair<StringRef, InputFile *> existing = ctx.config.mustMatch[k];
780   if (!existing.first.empty() && v != existing.first) {
781     std::string sourceStr = source ? toString(source) : "cmd-line";
782     std::string existingStr =
783         existing.second ? toString(existing.second) : "cmd-line";
784     fatal("/failifmismatch: mismatch detected for '" + k + "':\n>>> " +
785           existingStr + " has value " + existing.first + "\n>>> " + sourceStr +
786           " has value " + v);
787   }
788   ctx.config.mustMatch[k] = {v, source};
789 }
790 
791 // Convert Windows resource files (.res files) to a .obj file.
792 // Does what cvtres.exe does, but in-process and cross-platform.
793 MemoryBufferRef LinkerDriver::convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
794                                                ArrayRef<ObjFile *> objs) {
795   object::WindowsResourceParser parser(/* MinGW */ ctx.config.mingw);
796 
797   std::vector<std::string> duplicates;
798   for (MemoryBufferRef mb : mbs) {
799     std::unique_ptr<object::Binary> bin = check(object::createBinary(mb));
800     object::WindowsResource *rf = dyn_cast<object::WindowsResource>(bin.get());
801     if (!rf)
802       fatal("cannot compile non-resource file as resource");
803 
804     if (auto ec = parser.parse(rf, duplicates))
805       fatal(toString(std::move(ec)));
806   }
807 
808   // Note: This processes all .res files before all objs. Ideally they'd be
809   // handled in the same order they were linked (to keep the right one, if
810   // there are duplicates that are tolerated due to forceMultipleRes).
811   for (ObjFile *f : objs) {
812     object::ResourceSectionRef rsf;
813     if (auto ec = rsf.load(f->getCOFFObj()))
814       fatal(toString(f) + ": " + toString(std::move(ec)));
815 
816     if (auto ec = parser.parse(rsf, f->getName(), duplicates))
817       fatal(toString(std::move(ec)));
818   }
819 
820   if (ctx.config.mingw)
821     parser.cleanUpManifests(duplicates);
822 
823   for (const auto &dupeDiag : duplicates)
824     if (ctx.config.forceMultipleRes)
825       warn(dupeDiag);
826     else
827       error(dupeDiag);
828 
829   Expected<std::unique_ptr<MemoryBuffer>> e =
830       llvm::object::writeWindowsResourceCOFF(ctx.config.machine, parser,
831                                              ctx.config.timestamp);
832   if (!e)
833     fatal("failed to write .res to COFF: " + toString(e.takeError()));
834 
835   MemoryBufferRef mbref = **e;
836   make<std::unique_ptr<MemoryBuffer>>(std::move(*e)); // take ownership
837   return mbref;
838 }
839 
840 // Create OptTable
841 
842 // Create prefix string literals used in Options.td
843 #define PREFIX(NAME, VALUE)                                                    \
844   static constexpr llvm::StringLiteral NAME##_init[] = VALUE;                  \
845   static constexpr llvm::ArrayRef<llvm::StringLiteral> NAME(                   \
846       NAME##_init, std::size(NAME##_init) - 1);
847 #include "Options.inc"
848 #undef PREFIX
849 
850 // Create table mapping all options defined in Options.td
851 static constexpr llvm::opt::OptTable::Info infoTable[] = {
852 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
853 #include "Options.inc"
854 #undef OPTION
855 };
856 
857 COFFOptTable::COFFOptTable() : GenericOptTable(infoTable, true) {}
858 
859 // Set color diagnostics according to --color-diagnostics={auto,always,never}
860 // or --no-color-diagnostics flags.
861 static void handleColorDiagnostics(opt::InputArgList &args) {
862   auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
863                               OPT_no_color_diagnostics);
864   if (!arg)
865     return;
866   if (arg->getOption().getID() == OPT_color_diagnostics) {
867     lld::errs().enable_colors(true);
868   } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
869     lld::errs().enable_colors(false);
870   } else {
871     StringRef s = arg->getValue();
872     if (s == "always")
873       lld::errs().enable_colors(true);
874     else if (s == "never")
875       lld::errs().enable_colors(false);
876     else if (s != "auto")
877       error("unknown option: --color-diagnostics=" + s);
878   }
879 }
880 
881 static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
882   if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
883     StringRef s = arg->getValue();
884     if (s != "windows" && s != "posix")
885       error("invalid response file quoting: " + s);
886     if (s == "windows")
887       return cl::TokenizeWindowsCommandLine;
888     return cl::TokenizeGNUCommandLine;
889   }
890   // The COFF linker always defaults to Windows quoting.
891   return cl::TokenizeWindowsCommandLine;
892 }
893 
894 ArgParser::ArgParser(COFFLinkerContext &c) : ctx(c) {}
895 
896 // Parses a given list of options.
897 opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
898   // Make InputArgList from string vectors.
899   unsigned missingIndex;
900   unsigned missingCount;
901 
902   // We need to get the quoting style for response files before parsing all
903   // options so we parse here before and ignore all the options but
904   // --rsp-quoting and /lldignoreenv.
905   // (This means --rsp-quoting can't be added through %LINK%.)
906   opt::InputArgList args =
907       ctx.optTable.ParseArgs(argv, missingIndex, missingCount);
908 
909   // Expand response files (arguments in the form of @<filename>) and insert
910   // flags from %LINK% and %_LINK_%, and then parse the argument again.
911   SmallVector<const char *, 256> expandedArgv(argv.data(),
912                                               argv.data() + argv.size());
913   if (!args.hasArg(OPT_lldignoreenv))
914     addLINK(expandedArgv);
915   cl::ExpandResponseFiles(saver(), getQuotingStyle(args), expandedArgv);
916   args = ctx.optTable.ParseArgs(ArrayRef(expandedArgv).drop_front(),
917                                 missingIndex, missingCount);
918 
919   // Print the real command line if response files are expanded.
920   if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
921     std::string msg = "Command line:";
922     for (const char *s : expandedArgv)
923       msg += " " + std::string(s);
924     message(msg);
925   }
926 
927   // Save the command line after response file expansion so we can write it to
928   // the PDB if necessary. Mimic MSVC, which skips input files.
929   ctx.config.argv = {argv[0]};
930   for (opt::Arg *arg : args) {
931     if (arg->getOption().getKind() != opt::Option::InputClass) {
932       ctx.config.argv.emplace_back(args.getArgString(arg->getIndex()));
933     }
934   }
935 
936   // Handle /WX early since it converts missing argument warnings to errors.
937   errorHandler().fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
938 
939   if (missingCount)
940     fatal(Twine(args.getArgString(missingIndex)) + ": missing argument");
941 
942   handleColorDiagnostics(args);
943 
944   for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
945     std::string nearest;
946     if (ctx.optTable.findNearest(arg->getAsString(args), nearest) > 1)
947       warn("ignoring unknown argument '" + arg->getAsString(args) + "'");
948     else
949       warn("ignoring unknown argument '" + arg->getAsString(args) +
950            "', did you mean '" + nearest + "'");
951   }
952 
953   if (args.hasArg(OPT_lib))
954     warn("ignoring /lib since it's not the first argument");
955 
956   return args;
957 }
958 
959 // Tokenizes and parses a given string as command line in .drective section.
960 ParsedDirectives ArgParser::parseDirectives(StringRef s) {
961   ParsedDirectives result;
962   SmallVector<const char *, 16> rest;
963 
964   // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
965   // potentially every symbol in the object, so they must be handled quickly.
966   SmallVector<StringRef, 16> tokens;
967   cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
968   for (StringRef tok : tokens) {
969     if (tok.starts_with_insensitive("/export:") ||
970         tok.starts_with_insensitive("-export:"))
971       result.exports.push_back(tok.substr(strlen("/export:")));
972     else if (tok.starts_with_insensitive("/include:") ||
973              tok.starts_with_insensitive("-include:"))
974       result.includes.push_back(tok.substr(strlen("/include:")));
975     else if (tok.starts_with_insensitive("/exclude-symbols:") ||
976              tok.starts_with_insensitive("-exclude-symbols:"))
977       result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
978     else {
979       // Copy substrings that are not valid C strings. The tokenizer may have
980       // already copied quoted arguments for us, so those do not need to be
981       // copied again.
982       bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
983       rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
984     }
985   }
986 
987   // Make InputArgList from unparsed string vectors.
988   unsigned missingIndex;
989   unsigned missingCount;
990 
991   result.args = ctx.optTable.ParseArgs(rest, missingIndex, missingCount);
992 
993   if (missingCount)
994     fatal(Twine(result.args.getArgString(missingIndex)) + ": missing argument");
995   for (auto *arg : result.args.filtered(OPT_UNKNOWN))
996     warn("ignoring unknown argument: " + arg->getAsString(result.args));
997   return result;
998 }
999 
1000 // link.exe has an interesting feature. If LINK or _LINK_ environment
1001 // variables exist, their contents are handled as command line strings.
1002 // So you can pass extra arguments using them.
1003 void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
1004   // Concatenate LINK env and command line arguments, and then parse them.
1005   if (std::optional<std::string> s = Process::GetEnv("LINK")) {
1006     std::vector<const char *> v = tokenize(*s);
1007     argv.insert(std::next(argv.begin()), v.begin(), v.end());
1008   }
1009   if (std::optional<std::string> s = Process::GetEnv("_LINK_")) {
1010     std::vector<const char *> v = tokenize(*s);
1011     argv.insert(std::next(argv.begin()), v.begin(), v.end());
1012   }
1013 }
1014 
1015 std::vector<const char *> ArgParser::tokenize(StringRef s) {
1016   SmallVector<const char *, 16> tokens;
1017   cl::TokenizeWindowsCommandLine(s, saver(), tokens);
1018   return std::vector<const char *>(tokens.begin(), tokens.end());
1019 }
1020 
1021 void LinkerDriver::printHelp(const char *argv0) {
1022   ctx.optTable.printHelp(lld::outs(),
1023                          (std::string(argv0) + " [options] file...").c_str(),
1024                          "LLVM Linker", false);
1025 }
1026 
1027 } // namespace coff
1028 } // namespace lld
1029