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