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 "Config.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/Optional.h"
  21 #include "llvm/ADT/StringSwitch.h"
  22 #include "llvm/BinaryFormat/COFF.h"
  23 #include "llvm/Object/COFF.h"
  24 #include "llvm/Object/WindowsResource.h"
  25 #include "llvm/Option/Arg.h"
  26 #include "llvm/Option/ArgList.h"
  27 #include "llvm/Option/Option.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/FileUtilities.h"
  30 #include "llvm/Support/MathExtras.h"
  31 #include "llvm/Support/Process.h"
  32 #include "llvm/Support/Program.h"
  33 #include "llvm/Support/raw_ostream.h"
  34 #include "llvm/WindowsManifest/WindowsManifestMerger.h"
  35 #include <limits>
  36 #include <memory>
  37
  38 using namespace llvm::COFF;
  39 using namespace llvm;
  40 using llvm::sys::Process;
  41
  42 namespace lld {
  43 namespace coff {
  44 namespace {
  45
  46 const uint16_t SUBLANG_ENGLISH_US = 0x0409;
  47 const uint16_t RT_MANIFEST = 24;
  48
  49 class Executor {
  50 public:
  51   explicit Executor(StringRef s) : prog(saver().save(s)) {}
  52   void add(StringRef s) { args.push_back(saver().save(s)); }
  53   void add(std::string &s) { args.push_back(saver().save(s)); }
  54   void add(Twine s) { args.push_back(saver().save(s)); }
  55   void add(const char *s) { args.push_back(saver().save(s)); }
  56
  57   void run() {
  58     ErrorOr<std::string> exeOrErr = sys::findProgramByName(prog);
  59     if (auto ec = exeOrErr.getError())
  60       fatal("unable to find " + prog + " in PATH: " + ec.message());
  61     StringRef exe = saver().save(*exeOrErr);
  62     args.insert(args.begin(), exe);
  63
  64     if (sys::ExecuteAndWait(args[0], args) != 0)
  65       fatal("ExecuteAndWait failed: " +
  66             llvm::join(args.begin(), args.end(), " "));
  67   }
  68
  69 private:
  70   StringRef prog;
  71   std::vector<StringRef> args;
  72 };
  73
  74 } // anonymous namespace
  75
  76 // Parses a string in the form of "<integer>[,<integer>]".
  77 void parseNumbers(StringRef arg, uint64_t *addr, uint64_t *size) {
  78   StringRef s1, s2;
  79   std::tie(s1, s2) = arg.split(',');
  80   if (s1.getAsInteger(0, *addr))
  81     fatal("invalid number: " + s1);
  82   if (size && !s2.empty() && s2.getAsInteger(0, *size))
  83     fatal("invalid number: " + s2);
  84 }
  85
  86 // Parses a string in the form of "<integer>[.<integer>]".
  87 // If second number is not present, Minor is set to 0.
  88 void parseVersion(StringRef arg, uint32_t *major, uint32_t *minor) {
  89   StringRef s1, s2;
  90   std::tie(s1, s2) = arg.split('.');
  91   if (s1.getAsInteger(10, *major))
  92     fatal("invalid number: " + s1);
  93   *minor = 0;
  94   if (!s2.empty() && s2.getAsInteger(10, *minor))
  95     fatal("invalid number: " + s2);
  96 }
  97
  98 void parseGuard(StringRef fullArg) {
  99   SmallVector<StringRef, 1> splitArgs;
 100   fullArg.split(splitArgs, ",");
 101   for (StringRef arg : splitArgs) {
 102     if (arg.equals_insensitive("no"))
 103       config->guardCF = GuardCFLevel::Off;
 104     else if (arg.equals_insensitive("nolongjmp"))
 105       config->guardCF &= ~GuardCFLevel::LongJmp;
 106     else if (arg.equals_insensitive("noehcont"))
 107       config->guardCF &= ~GuardCFLevel::EHCont;
 108     else if (arg.equals_insensitive("cf"))
 109       config->guardCF = GuardCFLevel::CF;
 110     else if (arg.equals_insensitive("longjmp"))
 111       config->guardCF |= GuardCFLevel::CF | GuardCFLevel::LongJmp;
 112     else if (arg.equals_insensitive("ehcont"))
 113       config->guardCF |= GuardCFLevel::CF | GuardCFLevel::EHCont;
 114     else
 115       fatal("invalid argument to /guard: " + arg);
 116   }
 117 }
 118
 119 // Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
 120 void parseSubsystem(StringRef arg, WindowsSubsystem *sys, uint32_t *major,
 121                     uint32_t *minor, bool *gotVersion) {
 122   StringRef sysStr, ver;
 123   std::tie(sysStr, ver) = arg.split(',');
 124   std::string sysStrLower = sysStr.lower();
 125   *sys = StringSwitch<WindowsSubsystem>(sysStrLower)
 126     .Case("boot_application", IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
 127     .Case("console", IMAGE_SUBSYSTEM_WINDOWS_CUI)
 128     .Case("default", IMAGE_SUBSYSTEM_UNKNOWN)
 129     .Case("efi_application", IMAGE_SUBSYSTEM_EFI_APPLICATION)
 130     .Case("efi_boot_service_driver", IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
 131     .Case("efi_rom", IMAGE_SUBSYSTEM_EFI_ROM)
 132     .Case("efi_runtime_driver", IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
 133     .Case("native", IMAGE_SUBSYSTEM_NATIVE)
 134     .Case("posix", IMAGE_SUBSYSTEM_POSIX_CUI)
 135     .Case("windows", IMAGE_SUBSYSTEM_WINDOWS_GUI)
 136     .Default(IMAGE_SUBSYSTEM_UNKNOWN);
 137   if (*sys == IMAGE_SUBSYSTEM_UNKNOWN && sysStrLower != "default")
 138     fatal("unknown subsystem: " + sysStr);
 139   if (!ver.empty())
 140     parseVersion(ver, major, minor);
 141   if (gotVersion)
 142     *gotVersion = !ver.empty();
 143 }
 144
 145 // Parse a string of the form of "<from>=<to>".
 146 // Results are directly written to Config.
 147 void parseAlternateName(StringRef s) {
 148   StringRef from, to;
 149   std::tie(from, to) = s.split('=');
 150   if (from.empty() || to.empty())
 151     fatal("/alternatename: invalid argument: " + s);
 152   auto it = config->alternateNames.find(from);
 153   if (it != config->alternateNames.end() && it->second != to)
 154     fatal("/alternatename: conflicts: " + s);
 155   config->alternateNames.insert(it, std::make_pair(from, to));
 156 }
 157
 158 // Parse a string of the form of "<from>=<to>".
 159 // Results are directly written to Config.
 160 void parseMerge(StringRef s) {
 161   StringRef from, to;
 162   std::tie(from, to) = s.split('=');
 163   if (from.empty() || to.empty())
 164     fatal("/merge: invalid argument: " + s);
 165   if (from == ".rsrc" || to == ".rsrc")
 166     fatal("/merge: cannot merge '.rsrc' with any section");
 167   if (from == ".reloc" || to == ".reloc")
 168     fatal("/merge: cannot merge '.reloc' with any section");
 169   auto pair = config->merge.insert(std::make_pair(from, to));
 170   bool inserted = pair.second;
 171   if (!inserted) {
 172     StringRef existing = pair.first->second;
 173     if (existing != to)
 174       warn(s + ": already merged into " + existing);
 175   }
 176 }
 177
 178 void parsePDBPageSize(StringRef s) {
 179   int v;
 180   if (s.getAsInteger(0, v)) {
 181     error("/pdbpagesize: invalid argument: " + s);
 182     return;
 183   }
 184   if (v != 4096 && v != 8192 && v != 16384 && v != 32768) {
 185     error("/pdbpagesize: invalid argument: " + s);
 186     return;
 187   }
 188
 189   config->pdbPageSize = v;
 190 }
 191
 192 static uint32_t parseSectionAttributes(StringRef s) {
 193   uint32_t ret = 0;
 194   for (char c : s.lower()) {
 195     switch (c) {
 196     case 'd':
 197       ret |= IMAGE_SCN_MEM_DISCARDABLE;
 198       break;
 199     case 'e':
 200       ret |= IMAGE_SCN_MEM_EXECUTE;
 201       break;
 202     case 'k':
 203       ret |= IMAGE_SCN_MEM_NOT_CACHED;
 204       break;
 205     case 'p':
 206       ret |= IMAGE_SCN_MEM_NOT_PAGED;
 207       break;
 208     case 'r':
 209       ret |= IMAGE_SCN_MEM_READ;
 210       break;
 211     case 's':
 212       ret |= IMAGE_SCN_MEM_SHARED;
 213       break;
 214     case 'w':
 215       ret |= IMAGE_SCN_MEM_WRITE;
 216       break;
 217     default:
 218       fatal("/section: invalid argument: " + s);
 219     }
 220   }
 221   return ret;
 222 }
 223
 224 // Parses /section option argument.
 225 void parseSection(StringRef s) {
 226   StringRef name, attrs;
 227   std::tie(name, attrs) = s.split(',');
 228   if (name.empty() || attrs.empty())
 229     fatal("/section: invalid argument: " + s);
 230   config->section[name] = parseSectionAttributes(attrs);
 231 }
 232
 233 // Parses /aligncomm option argument.
 234 void parseAligncomm(StringRef s) {
 235   StringRef name, align;
 236   std::tie(name, align) = s.split(',');
 237   if (name.empty() || align.empty()) {
 238     error("/aligncomm: invalid argument: " + s);
 239     return;
 240   }
 241   int v;
 242   if (align.getAsInteger(0, v)) {
 243     error("/aligncomm: invalid argument: " + s);
 244     return;
 245   }
 246   config->alignComm[std::string(name)] =
 247       std::max(config->alignComm[std::string(name)], 1 << v);
 248 }
 249
 250 // Parses /functionpadmin option argument.
 251 void parseFunctionPadMin(llvm::opt::Arg *a, llvm::COFF::MachineTypes machine) {
 252   StringRef arg = a->getNumValues() ? a->getValue() : "";
 253   if (!arg.empty()) {
 254     // Optional padding in bytes is given.
 255     if (arg.getAsInteger(0, config->functionPadMin))
 256       error("/functionpadmin: invalid argument: " + arg);
 257     return;
 258   }
 259   // No optional argument given.
 260   // Set default padding based on machine, similar to link.exe.
 261   // There is no default padding for ARM platforms.
 262   if (machine == I386) {
 263     config->functionPadMin = 5;
 264   } else if (machine == AMD64) {
 265     config->functionPadMin = 6;
 266   } else {
 267     error("/functionpadmin: invalid argument for this machine: " + arg);
 268   }
 269 }
 270
 271 // Parses a string in the form of "EMBED[,=<integer>]|NO".
 272 // Results are directly written to Config.
 273 void parseManifest(StringRef arg) {
 274   if (arg.equals_insensitive("no")) {
 275     config->manifest = Configuration::No;
 276     return;
 277   }
 278   if (!arg.startswith_insensitive("embed"))
 279     fatal("invalid option " + arg);
 280   config->manifest = Configuration::Embed;
 281   arg = arg.substr(strlen("embed"));
 282   if (arg.empty())
 283     return;
 284   if (!arg.startswith_insensitive(",id="))
 285     fatal("invalid option " + arg);
 286   arg = arg.substr(strlen(",id="));
 287   if (arg.getAsInteger(0, config->manifestID))
 288     fatal("invalid option " + arg);
 289 }
 290
 291 // Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
 292 // Results are directly written to Config.
 293 void parseManifestUAC(StringRef arg) {
 294   if (arg.equals_insensitive("no")) {
 295     config->manifestUAC = false;
 296     return;
 297   }
 298   for (;;) {
 299     arg = arg.ltrim();
 300     if (arg.empty())
 301       return;
 302     if (arg.startswith_insensitive("level=")) {
 303       arg = arg.substr(strlen("level="));
 304       std::tie(config->manifestLevel, arg) = arg.split(" ");
 305       continue;
 306     }
 307     if (arg.startswith_insensitive("uiaccess=")) {
 308       arg = arg.substr(strlen("uiaccess="));
 309       std::tie(config->manifestUIAccess, arg) = arg.split(" ");
 310       continue;
 311     }
 312     fatal("invalid option " + arg);
 313   }
 314 }
 315
 316 // Parses a string in the form of "cd|net[,(cd|net)]*"
 317 // Results are directly written to Config.
 318 void parseSwaprun(StringRef arg) {
 319   do {
 320     StringRef swaprun, newArg;
 321     std::tie(swaprun, newArg) = arg.split(',');
 322     if (swaprun.equals_insensitive("cd"))
 323       config->swaprunCD = true;
 324     else if (swaprun.equals_insensitive("net"))
 325       config->swaprunNet = true;
 326     else if (swaprun.empty())
 327       error("/swaprun: missing argument");
 328     else
 329       error("/swaprun: invalid argument: " + swaprun);
 330     // To catch trailing commas, e.g. `/spawrun:cd,`
 331     if (newArg.empty() && arg.endswith(","))
 332       error("/swaprun: missing argument");
 333     arg = newArg;
 334   } while (!arg.empty());
 335 }
 336
 337 // An RAII temporary file class that automatically removes a temporary file.
 338 namespace {
 339 class TemporaryFile {
 340 public:
 341   TemporaryFile(StringRef prefix, StringRef extn, StringRef contents = "") {
 342     SmallString<128> s;
 343     if (auto ec = sys::fs::createTemporaryFile("lld-" + prefix, extn, s))
 344       fatal("cannot create a temporary file: " + ec.message());
 345     path = std::string(s.str());
 346
 347     if (!contents.empty()) {
 348       std::error_code ec;
 349       raw_fd_ostream os(path, ec, sys::fs::OF_None);
 350       if (ec)
 351         fatal("failed to open " + path + ": " + ec.message());
 352       os << contents;
 353     }
 354   }
 355
 356   TemporaryFile(TemporaryFile &&obj) {
 357     std::swap(path, obj.path);
 358   }
 359
 360   ~TemporaryFile() {
 361     if (path.empty())
 362       return;
 363     if (sys::fs::remove(path))
 364       fatal("failed to remove " + path);
 365   }
 366
 367   // Returns a memory buffer of this temporary file.
 368   // Note that this function does not leave the file open,
 369   // so it is safe to remove the file immediately after this function
 370   // is called (you cannot remove an opened file on Windows.)
 371   std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
 372     // IsVolatile=true forces MemoryBuffer to not use mmap().
 373     return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
 374                                        /*RequiresNullTerminator=*/false,
 375                                        /*IsVolatile=*/true),
 376                  "could not open " + path);
 377   }
 378
 379   std::string path;
 380 };
 381 }
 382
 383 static std::string createDefaultXml() {
 384   std::string ret;
 385   raw_string_ostream os(ret);
 386
 387   // Emit the XML. Note that we do *not* verify that the XML attributes are
 388   // syntactically correct. This is intentional for link.exe compatibility.
 389   os << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
 390      << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
 391      << "          manifestVersion=\"1.0\">\n";
 392   if (config->manifestUAC) {
 393     os << "  <trustInfo>\n"
 394        << "    <security>\n"
 395        << "      <requestedPrivileges>\n"
 396        << "         <requestedExecutionLevel level=" << config->manifestLevel
 397        << " uiAccess=" << config->manifestUIAccess << "/>\n"
 398        << "      </requestedPrivileges>\n"
 399        << "    </security>\n"
 400        << "  </trustInfo>\n";
 401   }
 402   for (auto manifestDependency : config->manifestDependencies) {
 403     os << "  <dependency>\n"
 404        << "    <dependentAssembly>\n"
 405        << "      <assemblyIdentity " << manifestDependency << " />\n"
 406        << "    </dependentAssembly>\n"
 407        << "  </dependency>\n";
 408   }
 409   os << "</assembly>\n";
 410   return os.str();
 411 }
 412
 413 static std::string createManifestXmlWithInternalMt(StringRef defaultXml) {
 414   std::unique_ptr<MemoryBuffer> defaultXmlCopy =
 415       MemoryBuffer::getMemBufferCopy(defaultXml);
 416
 417   windows_manifest::WindowsManifestMerger merger;
 418   if (auto e = merger.merge(*defaultXmlCopy.get()))
 419     fatal("internal manifest tool failed on default xml: " +
 420           toString(std::move(e)));
 421
 422   for (StringRef filename : config->manifestInput) {
 423     std::unique_ptr<MemoryBuffer> manifest =
 424         check(MemoryBuffer::getFile(filename));
 425     // Call takeBuffer to include in /reproduce: output if applicable.
 426     if (auto e = merger.merge(driver->takeBuffer(std::move(manifest))))
 427       fatal("internal manifest tool failed on file " + filename + ": " +
 428             toString(std::move(e)));
 429   }
 430
 431   return std::string(merger.getMergedManifest().get()->getBuffer());
 432 }
 433
 434 static std::string createManifestXmlWithExternalMt(StringRef defaultXml) {
 435   // Create the default manifest file as a temporary file.
 436   TemporaryFile Default("defaultxml", "manifest");
 437   std::error_code ec;
 438   raw_fd_ostream os(Default.path, ec, sys::fs::OF_TextWithCRLF);
 439   if (ec)
 440     fatal("failed to open " + Default.path + ": " + ec.message());
 441   os << defaultXml;
 442   os.close();
 443
 444   // Merge user-supplied manifests if they are given.  Since libxml2 is not
 445   // enabled, we must shell out to Microsoft's mt.exe tool.
 446   TemporaryFile user("user", "manifest");
 447
 448   Executor e("mt.exe");
 449   e.add("/manifest");
 450   e.add(Default.path);
 451   for (StringRef filename : config->manifestInput) {
 452     e.add("/manifest");
 453     e.add(filename);
 454
 455     // Manually add the file to the /reproduce: tar if needed.
 456     if (driver->tar)
 457       if (auto mbOrErr = MemoryBuffer::getFile(filename))
 458         driver->takeBuffer(std::move(*mbOrErr));
 459   }
 460   e.add("/nologo");
 461   e.add("/out:" + StringRef(user.path));
 462   e.run();
 463
 464   return std::string(
 465       CHECK(MemoryBuffer::getFile(user.path), "could not open " + user.path)
 466           .get()
 467           ->getBuffer());
 468 }
 469
 470 static std::string createManifestXml() {
 471   std::string defaultXml = createDefaultXml();
 472   if (config->manifestInput.empty())
 473     return defaultXml;
 474
 475   if (windows_manifest::isAvailable())
 476     return createManifestXmlWithInternalMt(defaultXml);
 477
 478   return createManifestXmlWithExternalMt(defaultXml);
 479 }
 480
 481 static std::unique_ptr<WritableMemoryBuffer>
 482 createMemoryBufferForManifestRes(size_t manifestSize) {
 483   size_t resSize = alignTo(
 484       object::WIN_RES_MAGIC_SIZE + object::WIN_RES_NULL_ENTRY_SIZE +
 485           sizeof(object::WinResHeaderPrefix) + sizeof(object::WinResIDs) +
 486           sizeof(object::WinResHeaderSuffix) + manifestSize,
 487       object::WIN_RES_DATA_ALIGNMENT);
 488   return WritableMemoryBuffer::getNewMemBuffer(resSize, config->outputFile +
 489                                                             ".manifest.res");
 490 }
 491
 492 static void writeResFileHeader(char *&buf) {
 493   memcpy(buf, COFF::WinResMagic, sizeof(COFF::WinResMagic));
 494   buf += sizeof(COFF::WinResMagic);
 495   memset(buf, 0, object::WIN_RES_NULL_ENTRY_SIZE);
 496   buf += object::WIN_RES_NULL_ENTRY_SIZE;
 497 }
 498
 499 static void writeResEntryHeader(char *&buf, size_t manifestSize) {
 500   // Write the prefix.
 501   auto *prefix = reinterpret_cast<object::WinResHeaderPrefix *>(buf);
 502   prefix->DataSize = manifestSize;
 503   prefix->HeaderSize = sizeof(object::WinResHeaderPrefix) +
 504                        sizeof(object::WinResIDs) +
 505                        sizeof(object::WinResHeaderSuffix);
 506   buf += sizeof(object::WinResHeaderPrefix);
 507
 508   // Write the Type/Name IDs.
 509   auto *iDs = reinterpret_cast<object::WinResIDs *>(buf);
 510   iDs->setType(RT_MANIFEST);
 511   iDs->setName(config->manifestID);
 512   buf += sizeof(object::WinResIDs);
 513
 514   // Write the suffix.
 515   auto *suffix = reinterpret_cast<object::WinResHeaderSuffix *>(buf);
 516   suffix->DataVersion = 0;
 517   suffix->MemoryFlags = object::WIN_RES_PURE_MOVEABLE;
 518   suffix->Language = SUBLANG_ENGLISH_US;
 519   suffix->Version = 0;
 520   suffix->Characteristics = 0;
 521   buf += sizeof(object::WinResHeaderSuffix);
 522 }
 523
 524 // Create a resource file containing a manifest XML.
 525 std::unique_ptr<MemoryBuffer> createManifestRes() {
 526   std::string manifest = createManifestXml();
 527
 528   std::unique_ptr<WritableMemoryBuffer> res =
 529       createMemoryBufferForManifestRes(manifest.size());
 530
 531   char *buf = res->getBufferStart();
 532   writeResFileHeader(buf);
 533   writeResEntryHeader(buf, manifest.size());
 534
 535   // Copy the manifest data into the .res file.
 536   std::copy(manifest.begin(), manifest.end(), buf);
 537   return std::move(res);
 538 }
 539
 540 void createSideBySideManifest() {
 541   std::string path = std::string(config->manifestFile);
 542   if (path == "")
 543     path = config->outputFile + ".manifest";
 544   std::error_code ec;
 545   raw_fd_ostream out(path, ec, sys::fs::OF_TextWithCRLF);
 546   if (ec)
 547     fatal("failed to create manifest: " + ec.message());
 548   out << createManifestXml();
 549 }
 550
 551 // Parse a string in the form of
 552 // "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
 553 // or "<name>=<dllname>.<name>".
 554 // Used for parsing /export arguments.
 555 Export parseExport(StringRef arg) {
 556   Export e;
 557   StringRef rest;
 558   std::tie(e.name, rest) = arg.split(",");
 559   if (e.name.empty())
 560     goto err;
 561
 562   if (e.name.contains('=')) {
 563     StringRef x, y;
 564     std::tie(x, y) = e.name.split("=");
 565
 566     // If "<name>=<dllname>.<name>".
 567     if (y.contains(".")) {
 568       e.name = x;
 569       e.forwardTo = y;
 570       return e;
 571     }
 572
 573     e.extName = x;
 574     e.name = y;
 575     if (e.name.empty())
 576       goto err;
 577   }
 578
 579   // If "<name>=<internalname>[,@ordinal[,NONAME]][,DATA][,PRIVATE]"
 580   while (!rest.empty()) {
 581     StringRef tok;
 582     std::tie(tok, rest) = rest.split(",");
 583     if (tok.equals_insensitive("noname")) {
 584       if (e.ordinal == 0)
 585         goto err;
 586       e.noname = true;
 587       continue;
 588     }
 589     if (tok.equals_insensitive("data")) {
 590       e.data = true;
 591       continue;
 592     }
 593     if (tok.equals_insensitive("constant")) {
 594       e.constant = true;
 595       continue;
 596     }
 597     if (tok.equals_insensitive("private")) {
 598       e.isPrivate = true;
 599       continue;
 600     }
 601     if (tok.startswith("@")) {
 602       int32_t ord;
 603       if (tok.substr(1).getAsInteger(0, ord))
 604         goto err;
 605       if (ord <= 0 || 65535 < ord)
 606         goto err;
 607       e.ordinal = ord;
 608       continue;
 609     }
 610     goto err;
 611   }
 612   return e;
 613
 614 err:
 615   fatal("invalid /export: " + arg);
 616 }
 617
 618 static StringRef undecorate(StringRef sym) {
 619   if (config->machine != I386)
 620     return sym;
 621   // In MSVC mode, a fully decorated stdcall function is exported
 622   // as-is with the leading underscore (with type IMPORT_NAME).
 623   // In MinGW mode, a decorated stdcall function gets the underscore
 624   // removed, just like normal cdecl functions.
 625   if (sym.startswith("_") && sym.contains('@') && !config->mingw)
 626     return sym;
 627   return sym.startswith("_") ? sym.substr(1) : sym;
 628 }
 629
 630 // Convert stdcall/fastcall style symbols into unsuffixed symbols,
 631 // with or without a leading underscore. (MinGW specific.)
 632 static StringRef killAt(StringRef sym, bool prefix) {
 633   if (sym.empty())
 634     return sym;
 635   // Strip any trailing stdcall suffix
 636   sym = sym.substr(0, sym.find('@', 1));
 637   if (!sym.startswith("@")) {
 638     if (prefix && !sym.startswith("_"))
 639       return saver().save("_" + sym);
 640     return sym;
 641   }
 642   // For fastcall, remove the leading @ and replace it with an
 643   // underscore, if prefixes are used.
 644   sym = sym.substr(1);
 645   if (prefix)
 646     sym = saver().save("_" + sym);
 647   return sym;
 648 }
 649
 650 // Performs error checking on all /export arguments.
 651 // It also sets ordinals.
 652 void fixupExports() {
 653   // Symbol ordinals must be unique.
 654   std::set<uint16_t> ords;
 655   for (Export &e : config->exports) {
 656     if (e.ordinal == 0)
 657       continue;
 658     if (!ords.insert(e.ordinal).second)
 659       fatal("duplicate export ordinal: " + e.name);
 660   }
 661
 662   for (Export &e : config->exports) {
 663     if (!e.forwardTo.empty()) {
 664       e.exportName = undecorate(e.name);
 665     } else {
 666       e.exportName = undecorate(e.extName.empty() ? e.name : e.extName);
 667     }
 668   }
 669
 670   if (config->killAt && config->machine == I386) {
 671     for (Export &e : config->exports) {
 672       e.name = killAt(e.name, true);
 673       e.exportName = killAt(e.exportName, false);
 674       e.extName = killAt(e.extName, true);
 675       e.symbolName = killAt(e.symbolName, true);
 676     }
 677   }
 678
 679   // Uniquefy by name.
 680   DenseMap<StringRef, Export *> map(config->exports.size());
 681   std::vector<Export> v;
 682   for (Export &e : config->exports) {
 683     auto pair = map.insert(std::make_pair(e.exportName, &e));
 684     bool inserted = pair.second;
 685     if (inserted) {
 686       v.push_back(e);
 687       continue;
 688     }
 689     Export *existing = pair.first->second;
 690     if (e == *existing || e.name != existing->name)
 691       continue;
 692     warn("duplicate /export option: " + e.name);
 693   }
 694   config->exports = std::move(v);
 695
 696   // Sort by name.
 697   std::sort(config->exports.begin(), config->exports.end(),
 698             [](const Export &a, const Export &b) {
 699               return a.exportName < b.exportName;
 700             });
 701 }
 702
 703 void assignExportOrdinals() {
 704   // Assign unique ordinals if default (= 0).
 705   uint32_t max = 0;
 706   for (Export &e : config->exports)
 707     max = std::max(max, (uint32_t)e.ordinal);
 708   for (Export &e : config->exports)
 709     if (e.ordinal == 0)
 710       e.ordinal = ++max;
 711   if (max > std::numeric_limits<uint16_t>::max())
 712     fatal("too many exported symbols (max " +
 713           Twine(std::numeric_limits<uint16_t>::max()) + ")");
 714 }
 715
 716 // Parses a string in the form of "key=value" and check
 717 // if value matches previous values for the same key.
 718 void checkFailIfMismatch(StringRef arg, InputFile *source) {
 719   StringRef k, v;
 720   std::tie(k, v) = arg.split('=');
 721   if (k.empty() || v.empty())
 722     fatal("/failifmismatch: invalid argument: " + arg);
 723   std::pair<StringRef, InputFile *> existing = config->mustMatch[k];
 724   if (!existing.first.empty() && v != existing.first) {
 725     std::string sourceStr = source ? toString(source) : "cmd-line";
 726     std::string existingStr =
 727         existing.second ? toString(existing.second) : "cmd-line";
 728     fatal("/failifmismatch: mismatch detected for '" + k + "':\n>>> " +
 729           existingStr + " has value " + existing.first + "\n>>> " + sourceStr +
 730           " has value " + v);
 731   }
 732   config->mustMatch[k] = {v, source};
 733 }
 734
 735 // Convert Windows resource files (.res files) to a .obj file.
 736 // Does what cvtres.exe does, but in-process and cross-platform.
 737 MemoryBufferRef convertResToCOFF(ArrayRef<MemoryBufferRef> mbs,
 738                                  ArrayRef<ObjFile *> objs) {
 739   object::WindowsResourceParser parser(/* MinGW */ config->mingw);
 740
 741   std::vector<std::string> duplicates;
 742   for (MemoryBufferRef mb : mbs) {
 743     std::unique_ptr<object::Binary> bin = check(object::createBinary(mb));
 744     object::WindowsResource *rf = dyn_cast<object::WindowsResource>(bin.get());
 745     if (!rf)
 746       fatal("cannot compile non-resource file as resource");
 747
 748     if (auto ec = parser.parse(rf, duplicates))
 749       fatal(toString(std::move(ec)));
 750   }
 751
 752   // Note: This processes all .res files before all objs. Ideally they'd be
 753   // handled in the same order they were linked (to keep the right one, if
 754   // there are duplicates that are tolerated due to forceMultipleRes).
 755   for (ObjFile *f : objs) {
 756     object::ResourceSectionRef rsf;
 757     if (auto ec = rsf.load(f->getCOFFObj()))
 758       fatal(toString(f) + ": " + toString(std::move(ec)));
 759
 760     if (auto ec = parser.parse(rsf, f->getName(), duplicates))
 761       fatal(toString(std::move(ec)));
 762   }
 763
 764   if (config->mingw)
 765     parser.cleanUpManifests(duplicates);
 766
 767   for (const auto &dupeDiag : duplicates)
 768     if (config->forceMultipleRes)
 769       warn(dupeDiag);
 770     else
 771       error(dupeDiag);
 772
 773   Expected<std::unique_ptr<MemoryBuffer>> e =
 774       llvm::object::writeWindowsResourceCOFF(config->machine, parser,
 775                                              config->timestamp);
 776   if (!e)
 777     fatal("failed to write .res to COFF: " + toString(e.takeError()));
 778
 779   MemoryBufferRef mbref = **e;
 780   make<std::unique_ptr<MemoryBuffer>>(std::move(*e)); // take ownership
 781   return mbref;
 782 }
 783
 784 // Create OptTable
 785
 786 // Create prefix string literals used in Options.td
 787 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
 788 #include "Options.inc"
 789 #undef PREFIX
 790
 791 // Create table mapping all options defined in Options.td
 792 static const llvm::opt::OptTable::Info infoTable[] = {
 793 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12)      \
 794   {X1, X2, X10,         X11,         OPT_##ID, llvm::opt::Option::KIND##Class, \
 795    X9, X8, OPT_##GROUP, OPT_##ALIAS, X7,       X12},
 796 #include "Options.inc"
 797 #undef OPTION
 798 };
 799
 800 COFFOptTable::COFFOptTable() : OptTable(infoTable, true) {}
 801
 802 COFFOptTable optTable;
 803
 804 // Set color diagnostics according to --color-diagnostics={auto,always,never}
 805 // or --no-color-diagnostics flags.
 806 static void handleColorDiagnostics(opt::InputArgList &args) {
 807   auto *arg = args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
 808                               OPT_no_color_diagnostics);
 809   if (!arg)
 810     return;
 811   if (arg->getOption().getID() == OPT_color_diagnostics) {
 812     lld::errs().enable_colors(true);
 813   } else if (arg->getOption().getID() == OPT_no_color_diagnostics) {
 814     lld::errs().enable_colors(false);
 815   } else {
 816     StringRef s = arg->getValue();
 817     if (s == "always")
 818       lld::errs().enable_colors(true);
 819     else if (s == "never")
 820       lld::errs().enable_colors(false);
 821     else if (s != "auto")
 822       error("unknown option: --color-diagnostics=" + s);
 823   }
 824 }
 825
 826 static cl::TokenizerCallback getQuotingStyle(opt::InputArgList &args) {
 827   if (auto *arg = args.getLastArg(OPT_rsp_quoting)) {
 828     StringRef s = arg->getValue();
 829     if (s != "windows" && s != "posix")
 830       error("invalid response file quoting: " + s);
 831     if (s == "windows")
 832       return cl::TokenizeWindowsCommandLine;
 833     return cl::TokenizeGNUCommandLine;
 834   }
 835   // The COFF linker always defaults to Windows quoting.
 836   return cl::TokenizeWindowsCommandLine;
 837 }
 838
 839 // Parses a given list of options.
 840 opt::InputArgList ArgParser::parse(ArrayRef<const char *> argv) {
 841   // Make InputArgList from string vectors.
 842   unsigned missingIndex;
 843   unsigned missingCount;
 844
 845   // We need to get the quoting style for response files before parsing all
 846   // options so we parse here before and ignore all the options but
 847   // --rsp-quoting and /lldignoreenv.
 848   // (This means --rsp-quoting can't be added through %LINK%.)
 849   opt::InputArgList args = optTable.ParseArgs(argv, missingIndex, missingCount);
 850
 851   // Expand response files (arguments in the form of @<filename>) and insert
 852   // flags from %LINK% and %_LINK_%, and then parse the argument again.
 853   SmallVector<const char *, 256> expandedArgv(argv.data(),
 854                                               argv.data() + argv.size());
 855   if (!args.hasArg(OPT_lldignoreenv))
 856     addLINK(expandedArgv);
 857   cl::ExpandResponseFiles(saver(), getQuotingStyle(args), expandedArgv);
 858   args = optTable.ParseArgs(makeArrayRef(expandedArgv).drop_front(),
 859                             missingIndex, missingCount);
 860
 861   // Print the real command line if response files are expanded.
 862   if (args.hasArg(OPT_verbose) && argv.size() != expandedArgv.size()) {
 863     std::string msg = "Command line:";
 864     for (const char *s : expandedArgv)
 865       msg += " " + std::string(s);
 866     message(msg);
 867   }
 868
 869   // Save the command line after response file expansion so we can write it to
 870   // the PDB if necessary.
 871   config->argv = {expandedArgv.begin(), expandedArgv.end()};
 872
 873   // Handle /WX early since it converts missing argument warnings to errors.
 874   errorHandler().fatalWarnings = args.hasFlag(OPT_WX, OPT_WX_no, false);
 875
 876   if (missingCount)
 877     fatal(Twine(args.getArgString(missingIndex)) + ": missing argument");
 878
 879   handleColorDiagnostics(args);
 880
 881   for (opt::Arg *arg : args.filtered(OPT_UNKNOWN)) {
 882     std::string nearest;
 883     if (optTable.findNearest(arg->getAsString(args), nearest) > 1)
 884       warn("ignoring unknown argument '" + arg->getAsString(args) + "'");
 885     else
 886       warn("ignoring unknown argument '" + arg->getAsString(args) +
 887            "', did you mean '" + nearest + "'");
 888   }
 889
 890   if (args.hasArg(OPT_lib))
 891     warn("ignoring /lib since it's not the first argument");
 892
 893   return args;
 894 }
 895
 896 // Tokenizes and parses a given string as command line in .drective section.
 897 ParsedDirectives ArgParser::parseDirectives(StringRef s) {
 898   ParsedDirectives result;
 899   SmallVector<const char *, 16> rest;
 900
 901   // Handle /EXPORT and /INCLUDE in a fast path. These directives can appear for
 902   // potentially every symbol in the object, so they must be handled quickly.
 903   SmallVector<StringRef, 16> tokens;
 904   cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
 905   for (StringRef tok : tokens) {
 906     if (tok.startswith_insensitive("/export:") ||
 907         tok.startswith_insensitive("-export:"))
 908       result.exports.push_back(tok.substr(strlen("/export:")));
 909     else if (tok.startswith_insensitive("/include:") ||
 910              tok.startswith_insensitive("-include:"))
 911       result.includes.push_back(tok.substr(strlen("/include:")));
 912     else {
 913       // Copy substrings that are not valid C strings. The tokenizer may have
 914       // already copied quoted arguments for us, so those do not need to be
 915       // copied again.
 916       bool HasNul = tok.end() != s.end() && tok.data()[tok.size()] == '\0';
 917       rest.push_back(HasNul ? tok.data() : saver().save(tok).data());
 918     }
 919   }
 920
 921   // Make InputArgList from unparsed string vectors.
 922   unsigned missingIndex;
 923   unsigned missingCount;
 924
 925   result.args = optTable.ParseArgs(rest, missingIndex, missingCount);
 926
 927   if (missingCount)
 928     fatal(Twine(result.args.getArgString(missingIndex)) + ": missing argument");
 929   for (auto *arg : result.args.filtered(OPT_UNKNOWN))
 930     warn("ignoring unknown argument: " + arg->getAsString(result.args));
 931   return result;
 932 }
 933
 934 // link.exe has an interesting feature. If LINK or _LINK_ environment
 935 // variables exist, their contents are handled as command line strings.
 936 // So you can pass extra arguments using them.
 937 void ArgParser::addLINK(SmallVector<const char *, 256> &argv) {
 938   // Concatenate LINK env and command line arguments, and then parse them.
 939   if (Optional<std::string> s = Process::GetEnv("LINK")) {
 940     std::vector<const char *> v = tokenize(*s);
 941     argv.insert(std::next(argv.begin()), v.begin(), v.end());
 942   }
 943   if (Optional<std::string> s = Process::GetEnv("_LINK_")) {
 944     std::vector<const char *> v = tokenize(*s);
 945     argv.insert(std::next(argv.begin()), v.begin(), v.end());
 946   }
 947 }
 948
 949 std::vector<const char *> ArgParser::tokenize(StringRef s) {
 950   SmallVector<const char *, 16> tokens;
 951   cl::TokenizeWindowsCommandLine(s, saver(), tokens);
 952   return std::vector<const char *>(tokens.begin(), tokens.end());
 953 }
 954
 955 void printHelp(const char *argv0) {
 956   optTable.printHelp(lld::outs(),
 957                      (std::string(argv0) + " [options] file...").c_str(),
 958                      "LLVM Linker", false);
 959 }
 960
 961 } // namespace coff
 962 } // namespace lld