lld/COFF/DriverUtils.cpp

   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 // 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       Err(ctx) << "/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     Err(ctx) << "/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       Err(ctx) << "/dependentloadflag: invalid argument: " << arg;
 276     return;
 277   }
 278   // MSVC linker reports error "no argument specified", although MSDN describes
 279   // argument as optional.
 280   Err(ctx) << "/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(ctx) << "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(ctx) << "invalid option " << arg;
 299   arg = arg.substr(strlen(",id="));
 300   if (arg.getAsInteger(0, ctx.config.manifestID))
 301     Fatal(ctx) << "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(ctx) << "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       Err(ctx) << "/swaprun: missing argument";
 338     else
 339       Err(ctx) << "/swaprun: invalid argument: " << swaprun;
 340     // To catch trailing commas, e.g. `/spawrun:cd,`
 341     if (newArg.empty() && arg.ends_with(","))
 342       Err(ctx) << "/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(COFFLinkerContext &ctx, StringRef prefix, StringRef extn,
 352                 StringRef contents = "")
 353       : ctx(ctx) {
 354     SmallString<128> s;
 355     if (auto ec = sys::fs::createTemporaryFile("lld-" + prefix, extn, s))
 356       Fatal(ctx) << "cannot create a temporary file: " << ec.message();
 357     path = std::string(s);
 358
 359     if (!contents.empty()) {
 360       std::error_code ec;
 361       raw_fd_ostream os(path, ec, sys::fs::OF_None);
 362       if (ec)
 363         Fatal(ctx) << "failed to open " << path << ": " << ec.message();
 364       os << contents;
 365     }
 366   }
 367
 368   TemporaryFile(TemporaryFile &&obj) noexcept : ctx(obj.ctx) {
 369     std::swap(path, obj.path);
 370   }
 371
 372   ~TemporaryFile() {
 373     if (path.empty())
 374       return;
 375     if (sys::fs::remove(path))
 376       Fatal(ctx) << "failed to remove " << path;
 377   }
 378
 379   // Returns a memory buffer of this temporary file.
 380   // Note that this function does not leave the file open,
 381   // so it is safe to remove the file immediately after this function
 382   // is called (you cannot remove an opened file on Windows.)
 383   std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
 384     // IsVolatile=true forces MemoryBuffer to not use mmap().
 385     return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
 386                                        /*RequiresNullTerminator=*/false,
 387                                        /*IsVolatile=*/true),
 388                  "could not open " + path);
 389   }
 390
 391   COFFLinkerContext &ctx;
 392   std::string path;
 393 };
 394 }
 395
 396 std::string LinkerDriver::createDefaultXml() {
 397   std::string ret;
 398   raw_string_ostream os(ret);
 399
 400   // Emit the XML. Note that we do *not* verify that the XML attributes are
 401   // syntactically correct. This is intentional for link.exe compatibility.
 402   os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
 403      << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
 404      << "          manifestVersion=\"1.0\">\n";
 405   if (ctx.config.manifestUAC) {
 406     os << "  <trustInfo>\n"
 407        << "    <security>\n"
 408        << "      <requestedPrivileges>\n"
 409        << "         <requestedExecutionLevel level=" << ctx.config.manifestLevel
 410        << " uiAccess=" << ctx.config.manifestUIAccess << "/>\n"
 411        << "      </requestedPrivileges>\n"
 412        << "    </security>\n"
 413        << "  </trustInfo>\n";
 414   }
 415   for (auto manifestDependency : ctx.config.manifestDependencies) {
 416     os << "  <dependency>\n"
 417        << "    <dependentAssembly>\n"
 418        << "      <assemblyIdentity " << manifestDependency << " />\n"
 419        << "    </dependentAssembly>\n"
 420        << "  </dependency>\n";
 421   }
 422   os << "</assembly>\n";
 423   return ret;
 424 }
 425
 426 std::string
 427 LinkerDriver::createManifestXmlWithInternalMt(StringRef defaultXml) {
 428   std::unique_ptr<MemoryBuffer> defaultXmlCopy =
 429       MemoryBuffer::getMemBufferCopy(defaultXml);
 430
 431   windows_manifest::WindowsManifestMerger merger;
 432   if (auto e = merger.merge(*defaultXmlCopy.get()))
 433     Fatal(ctx) << "internal manifest tool failed on default xml: "
 434                << toString(std::move(e));
 435
 436   for (StringRef filename : ctx.config.manifestInput) {
 437     std::unique_ptr<MemoryBuffer> manifest =
 438         check(MemoryBuffer::getFile(filename));
 439     // Call takeBuffer to include in /reproduce: output if applicable.
 440     if (auto e = merger.merge(takeBuffer(std::move(manifest))))
 441       Fatal(ctx) << "internal manifest tool failed on file " << filename << ": "
 442                  << toString(std::move(e));
 443   }
 444
 445   return std::string(merger.getMergedManifest().get()->getBuffer());
 446 }
 447
 448 std::string
 449 LinkerDriver::createManifestXmlWithExternalMt(StringRef defaultXml) {
 450   // Create the default manifest file as a temporary file.
 451   TemporaryFile Default(ctx, "defaultxml", "manifest");
 452   std::error_code ec;
 453   raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
 454   if (ec)
 455     Fatal(ctx) << "failed to open " << Default.path << ": " << ec.message();
 456   os << defaultXml;
 457   os.close();
 458
 459   // Merge user-supplied manifests if they are given.  Since libxml2 is not
 460   // enabled, we must shell out to Microsoft's mt.exe tool.
 461   TemporaryFile user(ctx, "user", "manifest");
 462
 463   Executor e("mt.exe");
 464   e.add("/manifest");
 465   e.add(Default.path);
 466   for (StringRef filename : ctx.config.manifestInput) {
 467     e.add("/manifest");
 468     e.add(filename);
 469
 470     // Manually add the file to the /reproduce: tar if needed.
 471     if (tar)
 472       if (auto mbOrErr = MemoryBuffer::getFile(filename))
 473         takeBuffer(std::move(*mbOrErr));
 474   }
 475   e.add("/nologo");
 476   e.add("/out:" + StringRef(user.path));
 477   e.run();
 478
 479   return std::string(
 480       CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
 481           .get()
 482           ->getBuffer());
 483 }
 484
 485 std::string LinkerDriver::createManifestXml() {
 486   std::string defaultXml = createDefaultXml();
 487   if (ctx.config.manifestInput.empty())
 488     return defaultXml;
 489
 490   if (windows_manifest::isAvailable())
 491     return createManifestXmlWithInternalMt(defaultXml);
 492
 493   return createManifestXmlWithExternalMt(defaultXml);
 494 }
 495
 496 std::unique_ptr<WritableMemoryBuffer>
 497 LinkerDriver::createMemoryBufferForManifestRes(size_t manifestSize) {
 498   size_t resSize = alignTo(
 499       object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
 500           sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
 501           sizeof(object::WinResHeaderSuffix) + manifestSize,
 502       object::WIN_RES_DATA_ALIGNMENT);
 503   return WritableMemoryBuffer::getNewMemBuffer(resSize, ctx.config.outputFile +
 504                                                             ".manifest.res");
 505 }
 506
 507 static void writeResFileHeader(char *&buf) {
 508   memcpy(buf, COFF::WinResMagic, sizeof(COFF::WinResMagic));
 509   buf += sizeof(COFF::WinResMagic);
 510   memset(buf, 0, object::WIN_RES_NULL_ENTRY_SIZE);
 511   buf += object::WIN_RES_NULL_ENTRY_SIZE;
 512 }
 513
 514 static void writeResEntryHeader(char *&buf, size_t manifestSize,
 515                                 int manifestID) {
 516   // Write the prefix.
 517   auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
 518   prefix->DataSize = manifestSize;
 519   prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
 520                        sizeof(object::WinResIDs) +
 521                        sizeof(object::WinResHeaderSuffix);
 522   buf += sizeof(object::WinResHeaderPrefix);
 523
 524   // Write the Type/Name IDs.
 525   auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
 526   iDs->setType(RT_MANIFEST);
 527   iDs->setName(manifestID);
 528   buf += sizeof(object::WinResIDs);
 529
 530   // Write the suffix.
 531   auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
 532   suffix->DataVersion = 0;
 533   suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
 534   suffix->Language = SUBLANG_ENGLISH_US;
 535   suffix->Version = 0;
 536   suffix->Characteristics = 0;
 537   buf += sizeof(object::WinResHeaderSuffix);
 538 }
 539
 540 // Create a resource file containing a manifest XML.
 541 std::unique_ptr<MemoryBuffer> LinkerDriver::createManifestRes() {
 542   std::string manifest = createManifestXml();
 543
 544   std::unique_ptr<WritableMemoryBuffer> res =
 545       createMemoryBufferForManifestRes(manifest.size());
 546
 547   char *buf = res->getBufferStart();
 548   writeResFileHeader(buf);
 549   writeResEntryHeader(buf, manifest.size(), ctx.config.manifestID);
 550
 551   // Copy the manifest data into the .res file.
 552   std::copy(manifest.begin(), manifest.end(), buf);
 553   return std::move(res);
 554 }
 555
 556 void LinkerDriver::createSideBySideManifest() {
 557   std::string path = std::string(ctx.config.manifestFile);
 558   if (path == "")
 559     path = ctx.config.outputFile + ".manifest";
 560   std::error_code ec;
 561   raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
 562   if (ec)
 563     Fatal(ctx) << "failed to create manifest: " << ec.message();
 564   out << createManifestXml();
 565 }
 566
 567 // Parse a string in the form of
 568 // "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
 569 // or "<name>=<dllname>.<name>".
 570 // Used for parsing /export arguments.
 571 Export LinkerDriver::parseExport(StringRef arg) {
 572   Export e;
 573   e.source = ExportSource::Export;
 574
 575   StringRef rest;
 576   std::tie(e.name, rest) = arg.split(",");
 577   if (e.name.empty())
 578     goto err;
 579
 580   if (e.name.contains('=')) {
 581     auto [x, y] = e.name.split("=");
 582
 583     // If "<name>=<dllname>.<name>".
 584     if (y.contains(".")) {
 585       e.name = x;
 586       e.forwardTo = y;
 587     } else {
 588       e.extName = x;
 589       e.name = y;
 590       if (e.name.empty())
 591         goto err;
 592     }
 593   }
 594
 595   // Optional parameters
 596   // "[,@ordinal[,NONAME]][,DATA][,PRIVATE][,EXPORTAS,exportname]"
 597   while (!rest.empty()) {
 598     StringRef tok;
 599     std::tie(tok, rest) = rest.split(",");
 600     if (tok.equals_insensitive("noname")) {
 601       if (e.ordinal == 0)
 602         goto err;
 603       e.noname = true;
 604       continue;
 605     }
 606     if (tok.equals_insensitive("data")) {
 607       e.data = true;
 608       continue;
 609     }
 610     if (tok.equals_insensitive("constant")) {
 611       e.constant = true;
 612       continue;
 613     }
 614     if (tok.equals_insensitive("private")) {
 615       e.isPrivate = true;
 616       continue;
 617     }
 618     if (tok.equals_insensitive("exportas")) {
 619       if (!rest.empty() && !rest.contains(','))
 620         e.exportAs = rest;
 621       else
 622         Err(ctx) << "invalid EXPORTAS value: " << rest;
 623       break;
 624     }
 625     if (tok.starts_with("@")) {
 626       int32_t ord;
 627       if (tok.substr(1).getAsInteger(0, ord))
 628         goto err;
 629       if (ord <= 0 || 65535 < ord)
 630         goto err;
 631       e.ordinal = ord;
 632       continue;
 633     }
 634     goto err;
 635   }
 636   return e;
 637
 638 err:
 639   Fatal(ctx) << "invalid /export: " << arg;
 640   llvm_unreachable("");
 641 }
 642
 643 // Convert stdcall/fastcall style symbols into unsuffixed symbols,
 644 // with or without a leading underscore. (MinGW specific.)
 645 static StringRef killAt(StringRef sym, bool prefix) {
 646   if (sym.empty())
 647     return sym;
 648   // Strip any trailing stdcall suffix
 649   sym = sym.substr(0, sym.find('@', 1));
 650   if (!sym.starts_with("@")) {
 651     if (prefix && !sym.starts_with("_"))
 652       return saver().save("_" + sym);
 653     return sym;
 654   }
 655   // For fastcall, remove the leading @ and replace it with an
 656   // underscore, if prefixes are used.
 657   sym = sym.substr(1);
 658   if (prefix)
 659     sym = saver().save("_" + sym);
 660   return sym;
 661 }
 662
 663 static StringRef exportSourceName(ExportSource s) {
 664   switch (s) {
 665   case ExportSource::Directives:
 666     return "source file (directives)";
 667   case ExportSource::Export:
 668     return "/export";
 669   case ExportSource::ModuleDefinition:
 670     return "/def";
 671   default:
 672     llvm_unreachable("unknown ExportSource");
 673   }
 674 }
 675
 676 // Performs error checking on all /export arguments.
 677 // It also sets ordinals.
 678 void LinkerDriver::fixupExports() {
 679   llvm::TimeTraceScope timeScope("Fixup exports");
 680   // Symbol ordinals must be unique.
 681   std::set<uint16_t> ords;
 682   for (Export &e : ctx.config.exports) {
 683     if (e.ordinal == 0)
 684       continue;
 685     if (!ords.insert(e.ordinal).second)
 686       Fatal(ctx) << "duplicate export ordinal: " << e.name;
 687   }
 688
 689   for (Export &e : ctx.config.exports) {
 690     if (!e.exportAs.empty()) {
 691       e.exportName = e.exportAs;
 692       continue;
 693     }
 694
 695     StringRef sym =
 696         !e.forwardTo.empty() || e.extName.empty() ? e.name : e.extName;
 697     if (ctx.config.machine == I386 && sym.starts_with("_")) {
 698       // In MSVC mode, a fully decorated stdcall function is exported
 699       // as-is with the leading underscore (with type IMPORT_NAME).
 700       // In MinGW mode, a decorated stdcall function gets the underscore
 701       // removed, just like normal cdecl functions.
 702       if (ctx.config.mingw || !sym.contains('@')) {
 703         e.exportName = sym.substr(1);
 704         continue;
 705       }
 706     }
 707     if (isArm64EC(ctx.config.machine) && !e.data && !e.constant) {
 708       if (std::optional<std::string> demangledName =
 709               getArm64ECDemangledFunctionName(sym)) {
 710         e.exportName = saver().save(*demangledName);
 711         continue;
 712       }
 713     }
 714     e.exportName = sym;
 715   }
 716
 717   if (ctx.config.killAt && ctx.config.machine == I386) {
 718     for (Export &e : ctx.config.exports) {
 719       e.name = killAt(e.name, true);
 720       e.exportName = killAt(e.exportName, false);
 721       e.extName = killAt(e.extName, true);
 722       e.symbolName = killAt(e.symbolName, true);
 723     }
 724   }
 725
 726   // Uniquefy by name.
 727   DenseMap<StringRef, std::pair<Export *, unsigned>> map(
 728       ctx.config.exports.size());
 729   std::vector<Export> v;
 730   for (Export &e : ctx.config.exports) {
 731     auto pair = map.insert(std::make_pair(e.exportName, std::make_pair(&e, 0)));
 732     bool inserted = pair.second;
 733     if (inserted) {
 734       pair.first->second.second = v.size();
 735       v.push_back(e);
 736       continue;
 737     }
 738     Export *existing = pair.first->second.first;
 739     if (e == *existing || e.name != existing->name)
 740       continue;
 741     // If the existing export comes from .OBJ directives, we are allowed to
 742     // overwrite it with /DEF: or /EXPORT without any warning, as MSVC link.exe
 743     // does.
 744     if (existing->source == ExportSource::Directives) {
 745       *existing = e;
 746       v[pair.first->second.second] = e;
 747       continue;
 748     }
 749     if (existing->source == e.source) {
 750       Warn(ctx) << "duplicate " << exportSourceName(existing->source)
 751                 << " option: " << e.name;
 752     } else {
 753       Warn(ctx) << "duplicate export: " << e.name << " first seen in "
 754                 << exportSourceName(existing->source) << ", now in "
 755                 << exportSourceName(e.source);
 756     }
 757   }
 758   ctx.config.exports = std::move(v);
 759
 760   // Sort by name.
 761   llvm::sort(ctx.config.exports, [](const Export &a, const Export &b) {
 762     return a.exportName < b.exportName;
 763   });
 764 }
 765
 766 void LinkerDriver::assignExportOrdinals() {
 767   // Assign unique ordinals if default (= 0).
 768   uint32_t max = 0;
 769   for (Export &e : ctx.config.exports)
 770     max = std::max(max, (uint32_t)e.ordinal);
 771   for (Export &e : ctx.config.exports)
 772     if (e.ordinal == 0)
 773       e.ordinal = ++max;
 774   if (max > std::numeric_limits<uint16_t>::max())
 775     Fatal(ctx) << "too many exported symbols (got " << max << ", max "
 776                << Twine(std::numeric_limits<uint16_t>::max()) << ")";
 777 }
 778
 779 // Parses a string in the form of "key=value" and check
 780 // if value matches previous values for the same key.
 781 void LinkerDriver::checkFailIfMismatch(StringRef arg, InputFile *source) {
 782   auto [k, v] = arg.split('=');
 783   if (k.empty() || v.empty())
 784     Fatal(ctx) << "/failifmismatch: invalid argument: " << arg;
 785   std::pair<StringRef, InputFile *> existing = ctx.config.mustMatch[k];
 786   if (!existing.first.empty() && v != existing.first) {
 787     std::string sourceStr = source ? toString(source) : "cmd-line";
 788     std::string existingStr =
 789         existing.second ? toString(existing.second) : "cmd-line";
 790     Fatal(ctx) << "/failifmismatch: mismatch detected for '" << k << "':\n>>> "
 791                << existingStr << " has value " << existing.first << "\n>>> "
 792                << sourceStr << " has value " << v;
 793   }
 794   ctx.config.mustMatch[k] = {v, source};
 795 }
 796
 797 // Convert Windows resource files (.res files) to a .obj file.
 798 // Does what cvtres.exe does, but in-process and cross-platform.
 799 MemoryBufferRef LinkerDriver::convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
 800                                                ArrayRef<ObjFile *> objs) {
 801   object::WindowsResourceParser parser(/* MinGW */ ctx.config.mingw);
 802
 803   std::vector<std::string> duplicates;
 804   for (MemoryBufferRef mb : mbs) {
 805     std::unique_ptr<object::Binary> bin = check(object::createBinary(mb));
 806     object::WindowsResource *rf = dyn_cast<object::WindowsResource>(bin.get());
 807     if (!rf)
 808       Fatal(ctx) << "cannot compile non-resource file as resource";
 809
 810     if (auto ec = parser.parse(rf, duplicates))
 811       Fatal(ctx) << toString(std::move(ec));
 812   }
 813
 814   // Note: This processes all .res files before all objs. Ideally they'd be
 815   // handled in the same order they were linked (to keep the right one, if
 816   // there are duplicates that are tolerated due to forceMultipleRes).
 817   for (ObjFile *f : objs) {
 818     object::ResourceSectionRef rsf;
 819     if (auto ec = rsf.load(f->getCOFFObj()))
 820       Fatal(ctx) << toString(f) << ": " << toString(std::move(ec));
 821
 822     if (auto ec = parser.parse(rsf, f->getName(), duplicates))
 823       Fatal(ctx) << toString(std::move(ec));
 824   }
 825
 826   if (ctx.config.mingw)
 827     parser.cleanUpManifests(duplicates);
 828
 829   for (const auto &dupeDiag : duplicates)
 830     if (ctx.config.forceMultipleRes)
 831       Warn(ctx) << dupeDiag;
 832     else
 833       Err(ctx) << dupeDiag;
 834
 835   Expected<std::unique_ptr<MemoryBuffer>> e =
 836       llvm::object::writeWindowsResourceCOFF(ctx.config.machine, parser,
 837                                              ctx.config.timestamp);
 838   if (!e)
 839     Fatal(ctx) << "failed to write .res to COFF: " << toString(e.takeError());
 840
 841   MemoryBufferRef mbref = **e;
 842   make<std::unique_ptr<MemoryBuffer>>(std::move(*e)); // take ownership
 843   return mbref;
 844 }
 845
 846 // Create OptTable
 847
 848 #define OPTTABLE_STR_TABLE_CODE
 849 #include "Options.inc"
 850 #undef OPTTABLE_STR_TABLE_CODE
 851
 852 // Create prefix string literals used in Options.td
 853 #define OPTTABLE_PREFIXES_TABLE_CODE
 854 #include "Options.inc"
 855 #undef OPTTABLE_PREFIXES_TABLE_CODE
 856
 857 // Create table mapping all options defined in Options.td
 858 static constexpr llvm::opt::OptTable::Info infoTable[] = {
 859 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
 860 #include "Options.inc"
 861 #undef OPTION
 862 };
 863
 864 COFFOptTable::COFFOptTable()
 865     : GenericOptTable(OptionStrTable, OptionPrefixesTable, infoTable, true) {}
 866
 867 // Set color diagnostics according to --color-diagnostics={auto,always,never}
 868 // or --no-color-diagnostics flags.
 869 static void handleColorDiagnostics(COFFLinkerContext &ctx,
 870                                    opt::InputArgList &args) {
 871   auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
 872                               OPT_no_color_diagnostics);
 873   if (!arg)
 874     return;
 875   if (arg->getOption().getID() == OPT_color_diagnostics) {
 876     ctx.e.errs().enable_colors(true);
 877   } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
 878     ctx.e.errs().enable_colors(false);
 879   } else {
 880     StringRef s = arg->getValue();
 881     if (s == "always")
 882       ctx.e.errs().enable_colors(true);
 883     else if (s == "never")
 884       ctx.e.errs().enable_colors(false);
 885     else if (s != "auto")
 886       Err(ctx) << "unknown option: --color-diagnostics=" << s;
 887   }
 888 }
 889
 890 static cl::TokenizerCallback getQuotingStyle(COFFLinkerContext &ctx,
 891                                              opt::InputArgList &args) {
 892   if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
 893     StringRef s = arg->getValue();
 894     if (s != "windows" && s != "posix")
 895       Err(ctx) << "invalid response file quoting: " << s;
 896     if (s == "windows")
 897       return cl::TokenizeWindowsCommandLine;
 898     return cl::TokenizeGNUCommandLine;
 899   }
 900   // The COFF linker always defaults to Windows quoting.
 901   return cl::TokenizeWindowsCommandLine;
 902 }
 903
 904 ArgParser::ArgParser(COFFLinkerContext &c) : ctx(c) {}
 905
 906 // Parses a given list of options.
 907 opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
 908   // Make InputArgList from string vectors.
 909   unsigned missingIndex;
 910   unsigned missingCount;
 911
 912   // We need to get the quoting style for response files before parsing all
 913   // options so we parse here before and ignore all the options but
 914   // --rsp-quoting and /lldignoreenv.
 915   // (This means --rsp-quoting can't be added through %LINK%.)
 916   opt::InputArgList args =
 917       ctx.optTable.ParseArgs(argv, missingIndex, missingCount);
 918
 919   // Expand response files (arguments in the form of @<filename>) and insert
 920   // flags from %LINK% and %_LINK_%, and then parse the argument again.
 921   SmallVector<const char *, 256> expandedArgv(argv.data(),
 922                                               argv.data() + argv.size());
 923   if (!args.hasArg(OPT_lldignoreenv))
 924     addLINK(expandedArgv);
 925   cl::ExpandResponseFiles(saver(), getQuotingStyle(ctx, args), expandedArgv);
 926   args = ctx.optTable.ParseArgs(ArrayRef(expandedArgv).drop_front(),
 927                                 missingIndex, missingCount);
 928
 929   // Print the real command line if response files are expanded.
 930   if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
 931     std::string msg = "Command line:";
 932     for (const char *s : expandedArgv)
 933       msg += " " + std::string(s);
 934     Msg(ctx) << msg;
 935   }
 936
 937   // Save the command line after response file expansion so we can write it to
 938   // the PDB if necessary. Mimic MSVC, which skips input files.
 939   ctx.config.argv = {argv[0]};
 940   for (opt::Arg *arg : args) {
 941     if (arg->getOption().getKind() != opt::Option::InputClass) {
 942       ctx.config.argv.emplace_back(args.getArgString(arg->getIndex()));
 943     }
 944   }
 945
 946   // Handle /WX early since it converts missing argument warnings to errors.
 947   ctx.e.fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
 948
 949   if (missingCount)
 950     Fatal(ctx) << args.getArgString(missingIndex) << ": missing argument";
 951
 952   handleColorDiagnostics(ctx, args);
 953
 954   for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
 955     std::string nearest;
 956     if (ctx.optTable.findNearest(arg->getAsString(args), nearest) > 1)
 957       Warn(ctx) << "ignoring unknown argument '" << arg->getAsString(args)
 958                 << "'";
 959     else
 960       Warn(ctx) << "ignoring unknown argument '" << arg->getAsString(args)
 961                 << "', did you mean '" << nearest << "'";
 962   }
 963
 964   if (args.hasArg(OPT_lib))
 965     Warn(ctx) << "ignoring /lib since it's not the first argument";
 966
 967   return args;
 968 }
 969
 970 // Tokenizes and parses a given string as command line in .drective section.
 971 ParsedDirectives ArgParser::parseDirectives(StringRef s) {
 972   ParsedDirectives result;
 973   SmallVector<const char *, 16> rest;
 974
 975   // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
 976   // potentially every symbol in the object, so they must be handled quickly.
 977   SmallVector<StringRef, 16> tokens;
 978   cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
 979   for (StringRef tok : tokens) {
 980     if (tok.starts_with_insensitive("/export:") ||
 981         tok.starts_with_insensitive("-export:"))
 982       result.exports.push_back(tok.substr(strlen("/export:")));
 983     else if (tok.starts_with_insensitive("/include:") ||
 984              tok.starts_with_insensitive("-include:"))
 985       result.includes.push_back(tok.substr(strlen("/include:")));
 986     else if (tok.starts_with_insensitive("/exclude-symbols:") ||
 987              tok.starts_with_insensitive("-exclude-symbols:"))
 988       result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
 989     else {
 990       // Copy substrings that are not valid C strings. The tokenizer may have
 991       // already copied quoted arguments for us, so those do not need to be
 992       // copied again.
 993       bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
 994       rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
 995     }
 996   }
 997
 998   // Make InputArgList from unparsed string vectors.
 999   unsigned missingIndex;
1000   unsigned missingCount;
1001
1002   result.args = ctx.optTable.ParseArgs(rest, missingIndex, missingCount);
1003
1004   if (missingCount)
1005     Fatal(ctx) << result.args.getArgString(missingIndex)
1006                << ": missing argument";
1007   for (auto *arg : result.args.filtered(OPT_UNKNOWN))
1008     Warn(ctx) << "ignoring unknown argument: " << arg->getAsString(result.args);
1009   return result;
1010 }
1011
1012 // link.exe has an interesting feature. If LINK or _LINK_ environment
1013 // variables exist, their contents are handled as command line strings.
1014 // So you can pass extra arguments using them.
1015 void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
1016   // Concatenate LINK env and command line arguments, and then parse them.
1017   if (std::optional<std::string> s = Process::GetEnv("LINK")) {
1018     std::vector<const char *> v = tokenize(*s);
1019     argv.insert(std::next(argv.begin()), v.begin(), v.end());
1020   }
1021   if (std::optional<std::string> s = Process::GetEnv("_LINK_")) {
1022     std::vector<const char *> v = tokenize(*s);
1023     argv.insert(std::next(argv.begin()), v.begin(), v.end());
1024   }
1025 }
1026
1027 std::vector<const char *> ArgParser::tokenize(StringRef s) {
1028   SmallVector<const char *, 16> tokens;
1029   cl::TokenizeWindowsCommandLine(s, saver(), tokens);
1030   return std::vector<const char *>(tokens.begin(), tokens.end());
1031 }
1032
1033 void LinkerDriver::printHelp(const char *argv0) {
1034   ctx.optTable.printHelp(ctx.e.outs(),
1035                          (std::string(argv0) + " [options] file...").c_str(),
1036                          "LLVM Linker", false);
1037 }
1038
1039 } // namespace coff
1040 } // namespace lld