clang/tools/driver/driver.cpp

   1 //===-- driver.cpp - Clang GCC-Compatible Driver --------------------------===//
   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 is the entry point to the clang driver; it is a thin wrapper
  10 // for functionality in the Driver clang library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/Driver/Driver.h"
  15 #include "clang/Basic/DiagnosticOptions.h"
  16 #include "clang/Basic/Stack.h"
  17 #include "clang/Config/config.h"
  18 #include "clang/Driver/Compilation.h"
  19 #include "clang/Driver/DriverDiagnostic.h"
  20 #include "clang/Driver/Options.h"
  21 #include "clang/Driver/ToolChain.h"
  22 #include "clang/Frontend/ChainedDiagnosticConsumer.h"
  23 #include "clang/Frontend/CompilerInvocation.h"
  24 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
  25 #include "clang/Frontend/TextDiagnosticPrinter.h"
  26 #include "clang/Frontend/Utils.h"
  27 #include "llvm/ADT/ArrayRef.h"
  28 #include "llvm/ADT/SmallString.h"
  29 #include "llvm/ADT/SmallVector.h"
  30 #include "llvm/Option/ArgList.h"
  31 #include "llvm/Option/OptTable.h"
  32 #include "llvm/Option/Option.h"
  33 #include "llvm/Support/CommandLine.h"
  34 #include "llvm/Support/CrashRecoveryContext.h"
  35 #include "llvm/Support/ErrorHandling.h"
  36 #include "llvm/Support/FileSystem.h"
  37 #include "llvm/Support/Host.h"
  38 #include "llvm/Support/InitLLVM.h"
  39 #include "llvm/Support/Path.h"
  40 #include "llvm/Support/Process.h"
  41 #include "llvm/Support/Program.h"
  42 #include "llvm/Support/Regex.h"
  43 #include "llvm/Support/Signals.h"
  44 #include "llvm/Support/StringSaver.h"
  45 #include "llvm/Support/TargetSelect.h"
  46 #include "llvm/Support/Timer.h"
  47 #include "llvm/Support/raw_ostream.h"
  48 #include <memory>
  49 #include <set>
  50 #include <system_error>
  51 using namespace clang;
  52 using namespace clang::driver;
  53 using namespace llvm::opt;
  54
  55 std::string GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
  56   if (!CanonicalPrefixes) {
  57     SmallString<128> ExecutablePath(Argv0);
  58     // Do a PATH lookup if Argv0 isn't a valid path.
  59     if (!llvm::sys::fs::exists(ExecutablePath))
  60       if (llvm::ErrorOr<std::string> P =
  61               llvm::sys::findProgramByName(ExecutablePath))
  62         ExecutablePath = *P;
  63     return ExecutablePath.str();
  64   }
  65
  66   // This just needs to be some symbol in the binary; C++ doesn't
  67   // allow taking the address of ::main however.
  68   void *P = (void*) (intptr_t) GetExecutablePath;
  69   return llvm::sys::fs::getMainExecutable(Argv0, P);
  70 }
  71
  72 static const char *GetStableCStr(std::set<std::string> &SavedStrings,
  73                                  StringRef S) {
  74   return SavedStrings.insert(S).first->c_str();
  75 }
  76
  77 /// ApplyQAOverride - Apply a list of edits to the input argument lists.
  78 ///
  79 /// The input string is a space separate list of edits to perform,
  80 /// they are applied in order to the input argument lists. Edits
  81 /// should be one of the following forms:
  82 ///
  83 ///  '#': Silence information about the changes to the command line arguments.
  84 ///
  85 ///  '^': Add FOO as a new argument at the beginning of the command line.
  86 ///
  87 ///  '+': Add FOO as a new argument at the end of the command line.
  88 ///
  89 ///  's/XXX/YYY/': Substitute the regular expression XXX with YYY in the command
  90 ///  line.
  91 ///
  92 ///  'xOPTION': Removes all instances of the literal argument OPTION.
  93 ///
  94 ///  'XOPTION': Removes all instances of the literal argument OPTION,
  95 ///  and the following argument.
  96 ///
  97 ///  'Ox': Removes all flags matching 'O' or 'O[sz0-9]' and adds 'Ox'
  98 ///  at the end of the command line.
  99 ///
 100 /// \param OS - The stream to write edit information to.
 101 /// \param Args - The vector of command line arguments.
 102 /// \param Edit - The override command to perform.
 103 /// \param SavedStrings - Set to use for storing string representations.
 104 static void ApplyOneQAOverride(raw_ostream &OS,
 105                                SmallVectorImpl<const char*> &Args,
 106                                StringRef Edit,
 107                                std::set<std::string> &SavedStrings) {
 108   // This does not need to be efficient.
 109
 110   if (Edit[0] == '^') {
 111     const char *Str =
 112       GetStableCStr(SavedStrings, Edit.substr(1));
 113     OS << "### Adding argument " << Str << " at beginning\n";
 114     Args.insert(Args.begin() + 1, Str);
 115   } else if (Edit[0] == '+') {
 116     const char *Str =
 117       GetStableCStr(SavedStrings, Edit.substr(1));
 118     OS << "### Adding argument " << Str << " at end\n";
 119     Args.push_back(Str);
 120   } else if (Edit[0] == 's' && Edit[1] == '/' && Edit.endswith("/") &&
 121              Edit.slice(2, Edit.size()-1).find('/') != StringRef::npos) {
 122     StringRef MatchPattern = Edit.substr(2).split('/').first;
 123     StringRef ReplPattern = Edit.substr(2).split('/').second;
 124     ReplPattern = ReplPattern.slice(0, ReplPattern.size()-1);
 125
 126     for (unsigned i = 1, e = Args.size(); i != e; ++i) {
 127       // Ignore end-of-line response file markers
 128       if (Args[i] == nullptr)
 129         continue;
 130       std::string Repl = llvm::Regex(MatchPattern).sub(ReplPattern, Args[i]);
 131
 132       if (Repl != Args[i]) {
 133         OS << "### Replacing '" << Args[i] << "' with '" << Repl << "'\n";
 134         Args[i] = GetStableCStr(SavedStrings, Repl);
 135       }
 136     }
 137   } else if (Edit[0] == 'x' || Edit[0] == 'X') {
 138     auto Option = Edit.substr(1);
 139     for (unsigned i = 1; i < Args.size();) {
 140       if (Option == Args[i]) {
 141         OS << "### Deleting argument " << Args[i] << '\n';
 142         Args.erase(Args.begin() + i);
 143         if (Edit[0] == 'X') {
 144           if (i < Args.size()) {
 145             OS << "### Deleting argument " << Args[i] << '\n';
 146             Args.erase(Args.begin() + i);
 147           } else
 148             OS << "### Invalid X edit, end of command line!\n";
 149         }
 150       } else
 151         ++i;
 152     }
 153   } else if (Edit[0] == 'O') {
 154     for (unsigned i = 1; i < Args.size();) {
 155       const char *A = Args[i];
 156       // Ignore end-of-line response file markers
 157       if (A == nullptr)
 158         continue;
 159       if (A[0] == '-' && A[1] == 'O' &&
 160           (A[2] == '\0' ||
 161            (A[3] == '\0' && (A[2] == 's' || A[2] == 'z' ||
 162                              ('0' <= A[2] && A[2] <= '9'))))) {
 163         OS << "### Deleting argument " << Args[i] << '\n';
 164         Args.erase(Args.begin() + i);
 165       } else
 166         ++i;
 167     }
 168     OS << "### Adding argument " << Edit << " at end\n";
 169     Args.push_back(GetStableCStr(SavedStrings, '-' + Edit.str()));
 170   } else {
 171     OS << "### Unrecognized edit: " << Edit << "\n";
 172   }
 173 }
 174
 175 /// ApplyQAOverride - Apply a comma separate list of edits to the
 176 /// input argument lists. See ApplyOneQAOverride.
 177 static void ApplyQAOverride(SmallVectorImpl<const char*> &Args,
 178                             const char *OverrideStr,
 179                             std::set<std::string> &SavedStrings) {
 180   raw_ostream *OS = &llvm::errs();
 181
 182   if (OverrideStr[0] == '#') {
 183     ++OverrideStr;
 184     OS = &llvm::nulls();
 185   }
 186
 187   *OS << "### CCC_OVERRIDE_OPTIONS: " << OverrideStr << "\n";
 188
 189   // This does not need to be efficient.
 190
 191   const char *S = OverrideStr;
 192   while (*S) {
 193     const char *End = ::strchr(S, ' ');
 194     if (!End)
 195       End = S + strlen(S);
 196     if (End != S)
 197       ApplyOneQAOverride(*OS, Args, std::string(S, End), SavedStrings);
 198     S = End;
 199     if (*S != '\0')
 200       ++S;
 201   }
 202 }
 203
 204 extern int cc1_main(ArrayRef<const char *> Argv, const char *Argv0,
 205                     void *MainAddr);
 206 extern int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0,
 207                       void *MainAddr);
 208 extern int cc1gen_reproducer_main(ArrayRef<const char *> Argv,
 209                                   const char *Argv0, void *MainAddr);
 210
 211 static void insertTargetAndModeArgs(const ParsedClangName &NameParts,
 212                                     SmallVectorImpl<const char *> &ArgVector,
 213                                     std::set<std::string> &SavedStrings) {
 214   // Put target and mode arguments at the start of argument list so that
 215   // arguments specified in command line could override them. Avoid putting
 216   // them at index 0, as an option like '-cc1' must remain the first.
 217   int InsertionPoint = 0;
 218   if (ArgVector.size() > 0)
 219     ++InsertionPoint;
 220
 221   if (NameParts.DriverMode) {
 222     // Add the mode flag to the arguments.
 223     ArgVector.insert(ArgVector.begin() + InsertionPoint,
 224                      GetStableCStr(SavedStrings, NameParts.DriverMode));
 225   }
 226
 227   if (NameParts.TargetIsValid) {
 228     const char *arr[] = {"-target", GetStableCStr(SavedStrings,
 229                                                   NameParts.TargetPrefix)};
 230     ArgVector.insert(ArgVector.begin() + InsertionPoint,
 231                      std::begin(arr), std::end(arr));
 232   }
 233 }
 234
 235 static void getCLEnvVarOptions(std::string &EnvValue, llvm::StringSaver &Saver,
 236                                SmallVectorImpl<const char *> &Opts) {
 237   llvm::cl::TokenizeWindowsCommandLine(EnvValue, Saver, Opts);
 238   // The first instance of '#' should be replaced with '=' in each option.
 239   for (const char *Opt : Opts)
 240     if (char *NumberSignPtr = const_cast<char *>(::strchr(Opt, '#')))
 241       *NumberSignPtr = '=';
 242 }
 243
 244 static void SetBackdoorDriverOutputsFromEnvVars(Driver &TheDriver) {
 245   // Handle CC_PRINT_OPTIONS and CC_PRINT_OPTIONS_FILE.
 246   TheDriver.CCPrintOptions = !!::getenv("CC_PRINT_OPTIONS");
 247   if (TheDriver.CCPrintOptions)
 248     TheDriver.CCPrintOptionsFilename = ::getenv("CC_PRINT_OPTIONS_FILE");
 249
 250   // Handle CC_PRINT_HEADERS and CC_PRINT_HEADERS_FILE.
 251   TheDriver.CCPrintHeaders = !!::getenv("CC_PRINT_HEADERS");
 252   if (TheDriver.CCPrintHeaders)
 253     TheDriver.CCPrintHeadersFilename = ::getenv("CC_PRINT_HEADERS_FILE");
 254
 255   // Handle CC_LOG_DIAGNOSTICS and CC_LOG_DIAGNOSTICS_FILE.
 256   TheDriver.CCLogDiagnostics = !!::getenv("CC_LOG_DIAGNOSTICS");
 257   if (TheDriver.CCLogDiagnostics)
 258     TheDriver.CCLogDiagnosticsFilename = ::getenv("CC_LOG_DIAGNOSTICS_FILE");
 259 }
 260
 261 static void FixupDiagPrefixExeName(TextDiagnosticPrinter *DiagClient,
 262                                    const std::string &Path) {
 263   // If the clang binary happens to be named cl.exe for compatibility reasons,
 264   // use clang-cl.exe as the prefix to avoid confusion between clang and MSVC.
 265   StringRef ExeBasename(llvm::sys::path::stem(Path));
 266   if (ExeBasename.equals_lower("cl"))
 267     ExeBasename = "clang-cl";
 268   DiagClient->setPrefix(ExeBasename);
 269 }
 270
 271 // This lets us create the DiagnosticsEngine with a properly-filled-out
 272 // DiagnosticOptions instance.
 273 static DiagnosticOptions *
 274 CreateAndPopulateDiagOpts(ArrayRef<const char *> argv, bool &UseNewCC1Process) {
 275   auto *DiagOpts = new DiagnosticOptions;
 276   unsigned MissingArgIndex, MissingArgCount;
 277   InputArgList Args = getDriverOptTable().ParseArgs(
 278       argv.slice(1), MissingArgIndex, MissingArgCount);
 279   // We ignore MissingArgCount and the return value of ParseDiagnosticArgs.
 280   // Any errors that would be diagnosed here will also be diagnosed later,
 281   // when the DiagnosticsEngine actually exists.
 282   (void)ParseDiagnosticArgs(*DiagOpts, Args);
 283
 284   UseNewCC1Process =
 285       Args.hasFlag(clang::driver::options::OPT_fno_integrated_cc1,
 286                    clang::driver::options::OPT_fintegrated_cc1,
 287                    /*Default=*/CLANG_SPAWN_CC1);
 288
 289   return DiagOpts;
 290 }
 291
 292 static void SetInstallDir(SmallVectorImpl<const char *> &argv,
 293                           Driver &TheDriver, bool CanonicalPrefixes) {
 294   // Attempt to find the original path used to invoke the driver, to determine
 295   // the installed path. We do this manually, because we want to support that
 296   // path being a symlink.
 297   SmallString<128> InstalledPath(argv[0]);
 298
 299   // Do a PATH lookup, if there are no directory components.
 300   if (llvm::sys::path::filename(InstalledPath) == InstalledPath)
 301     if (llvm::ErrorOr<std::string> Tmp = llvm::sys::findProgramByName(
 302             llvm::sys::path::filename(InstalledPath.str())))
 303       InstalledPath = *Tmp;
 304
 305   // FIXME: We don't actually canonicalize this, we just make it absolute.
 306   if (CanonicalPrefixes)
 307     llvm::sys::fs::make_absolute(InstalledPath);
 308
 309   StringRef InstalledPathParent(llvm::sys::path::parent_path(InstalledPath));
 310   if (llvm::sys::fs::exists(InstalledPathParent))
 311     TheDriver.setInstalledDir(InstalledPathParent);
 312 }
 313
 314 static int ExecuteCC1Tool(SmallVectorImpl<const char *> &ArgV) {
 315   // If we call the cc1 tool from the clangDriver library (through
 316   // Driver::CC1Main), we need to clean up the options usage count. The options
 317   // are currently global, and they might have been used previously by the
 318   // driver.
 319   llvm::cl::ResetAllOptionOccurrences();
 320
 321   llvm::BumpPtrAllocator A;
 322   llvm::StringSaver Saver(A);
 323   llvm::cl::ExpandResponseFiles(Saver, &llvm::cl::TokenizeGNUCommandLine, ArgV,
 324                                 /*MarkEOLs=*/false);
 325   StringRef Tool = ArgV[1];
 326   void *GetExecutablePathVP = (void *)(intptr_t)GetExecutablePath;
 327   if (Tool == "-cc1")
 328     return cc1_main(makeArrayRef(ArgV).slice(2), ArgV[0], GetExecutablePathVP);
 329   if (Tool == "-cc1as")
 330     return cc1as_main(makeArrayRef(ArgV).slice(2), ArgV[0],
 331                       GetExecutablePathVP);
 332   if (Tool == "-cc1gen-reproducer")
 333     return cc1gen_reproducer_main(makeArrayRef(ArgV).slice(2), ArgV[0],
 334                                   GetExecutablePathVP);
 335   // Reject unknown tools.
 336   llvm::errs() << "error: unknown integrated tool '" << Tool << "'. "
 337                << "Valid tools include '-cc1' and '-cc1as'.\n";
 338   return 1;
 339 }
 340
 341 int main(int argc_, const char **argv_) {
 342   noteBottomOfStack();
 343   llvm::InitLLVM X(argc_, argv_);
 344   SmallVector<const char *, 256> argv(argv_, argv_ + argc_);
 345
 346   if (llvm::sys::Process::FixupStandardFileDescriptors())
 347     return 1;
 348
 349   llvm::InitializeAllTargets();
 350   auto TargetAndMode = ToolChain::getTargetAndModeFromProgramName(argv[0]);
 351
 352   llvm::BumpPtrAllocator A;
 353   llvm::StringSaver Saver(A);
 354
 355   // Parse response files using the GNU syntax, unless we're in CL mode. There
 356   // are two ways to put clang in CL compatibility mode: argv[0] is either
 357   // clang-cl or cl, or --driver-mode=cl is on the command line. The normal
 358   // command line parsing can't happen until after response file parsing, so we
 359   // have to manually search for a --driver-mode=cl argument the hard way.
 360   // Finally, our -cc1 tools don't care which tokenization mode we use because
 361   // response files written by clang will tokenize the same way in either mode.
 362   bool ClangCLMode = false;
 363   if (StringRef(TargetAndMode.DriverMode).equals("--driver-mode=cl") ||
 364       llvm::find_if(argv, [](const char *F) {
 365         return F && strcmp(F, "--driver-mode=cl") == 0;
 366       }) != argv.end()) {
 367     ClangCLMode = true;
 368   }
 369   enum { Default, POSIX, Windows } RSPQuoting = Default;
 370   for (const char *F : argv) {
 371     if (strcmp(F, "--rsp-quoting=posix") == 0)
 372       RSPQuoting = POSIX;
 373     else if (strcmp(F, "--rsp-quoting=windows") == 0)
 374       RSPQuoting = Windows;
 375   }
 376
 377   // Determines whether we want nullptr markers in argv to indicate response
 378   // files end-of-lines. We only use this for the /LINK driver argument with
 379   // clang-cl.exe on Windows.
 380   bool MarkEOLs = ClangCLMode;
 381
 382   llvm::cl::TokenizerCallback Tokenizer;
 383   if (RSPQuoting == Windows || (RSPQuoting == Default && ClangCLMode))
 384     Tokenizer = &llvm::cl::TokenizeWindowsCommandLine;
 385   else
 386     Tokenizer = &llvm::cl::TokenizeGNUCommandLine;
 387
 388   if (MarkEOLs && argv.size() > 1 && StringRef(argv[1]).startswith("-cc1"))
 389     MarkEOLs = false;
 390   llvm::cl::ExpandResponseFiles(Saver, Tokenizer, argv, MarkEOLs);
 391
 392   // Handle -cc1 integrated tools, even if -cc1 was expanded from a response
 393   // file.
 394   auto FirstArg = std::find_if(argv.begin() + 1, argv.end(),
 395                                [](const char *A) { return A != nullptr; });
 396   if (FirstArg != argv.end() && StringRef(*FirstArg).startswith("-cc1")) {
 397     // If -cc1 came from a response file, remove the EOL sentinels.
 398     if (MarkEOLs) {
 399       auto newEnd = std::remove(argv.begin(), argv.end(), nullptr);
 400       argv.resize(newEnd - argv.begin());
 401     }
 402     return ExecuteCC1Tool(argv);
 403   }
 404
 405   // Handle options that need handling before the real command line parsing in
 406   // Driver::BuildCompilation()
 407   bool CanonicalPrefixes = true;
 408   for (int i = 1, size = argv.size(); i < size; ++i) {
 409     // Skip end-of-line response file markers
 410     if (argv[i] == nullptr)
 411       continue;
 412     if (StringRef(argv[i]) == "-no-canonical-prefixes") {
 413       CanonicalPrefixes = false;
 414       break;
 415     }
 416   }
 417
 418   // Handle CL and _CL_ which permits additional command line options to be
 419   // prepended or appended.
 420   if (ClangCLMode) {
 421     // Arguments in "CL" are prepended.
 422     llvm::Optional<std::string> OptCL = llvm::sys::Process::GetEnv("CL");
 423     if (OptCL.hasValue()) {
 424       SmallVector<const char *, 8> PrependedOpts;
 425       getCLEnvVarOptions(OptCL.getValue(), Saver, PrependedOpts);
 426
 427       // Insert right after the program name to prepend to the argument list.
 428       argv.insert(argv.begin() + 1, PrependedOpts.begin(), PrependedOpts.end());
 429     }
 430     // Arguments in "_CL_" are appended.
 431     llvm::Optional<std::string> Opt_CL_ = llvm::sys::Process::GetEnv("_CL_");
 432     if (Opt_CL_.hasValue()) {
 433       SmallVector<const char *, 8> AppendedOpts;
 434       getCLEnvVarOptions(Opt_CL_.getValue(), Saver, AppendedOpts);
 435
 436       // Insert at the end of the argument list to append.
 437       argv.append(AppendedOpts.begin(), AppendedOpts.end());
 438     }
 439   }
 440
 441   std::set<std::string> SavedStrings;
 442   // Handle CCC_OVERRIDE_OPTIONS, used for editing a command line behind the
 443   // scenes.
 444   if (const char *OverrideStr = ::getenv("CCC_OVERRIDE_OPTIONS")) {
 445     // FIXME: Driver shouldn't take extra initial argument.
 446     ApplyQAOverride(argv, OverrideStr, SavedStrings);
 447   }
 448
 449   std::string Path = GetExecutablePath(argv[0], CanonicalPrefixes);
 450
 451   // Whether the cc1 tool should be called inside the current process, or if we
 452   // should spawn a new clang subprocess (old behavior).
 453   // Not having an additional process saves some execution time of Windows,
 454   // and makes debugging and profiling easier.
 455   bool UseNewCC1Process;
 456
 457   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =
 458       CreateAndPopulateDiagOpts(argv, UseNewCC1Process);
 459
 460   TextDiagnosticPrinter *DiagClient
 461     = new TextDiagnosticPrinter(llvm::errs(), &*DiagOpts);
 462   FixupDiagPrefixExeName(DiagClient, Path);
 463
 464   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
 465
 466   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
 467
 468   if (!DiagOpts->DiagnosticSerializationFile.empty()) {
 469     auto SerializedConsumer =
 470         clang::serialized_diags::create(DiagOpts->DiagnosticSerializationFile,
 471                                         &*DiagOpts, /*MergeChildRecords=*/true);
 472     Diags.setClient(new ChainedDiagnosticConsumer(
 473         Diags.takeClient(), std::move(SerializedConsumer)));
 474   }
 475
 476   ProcessWarningOptions(Diags, *DiagOpts, /*ReportDiags=*/false);
 477
 478   Driver TheDriver(Path, llvm::sys::getDefaultTargetTriple(), Diags);
 479   SetInstallDir(argv, TheDriver, CanonicalPrefixes);
 480   TheDriver.setTargetAndMode(TargetAndMode);
 481
 482   insertTargetAndModeArgs(TargetAndMode, argv, SavedStrings);
 483
 484   SetBackdoorDriverOutputsFromEnvVars(TheDriver);
 485
 486   if (!UseNewCC1Process) {
 487     TheDriver.CC1Main = &ExecuteCC1Tool;
 488     // Ensure the CC1Command actually catches cc1 crashes
 489     llvm::CrashRecoveryContext::Enable();
 490   }
 491
 492   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(argv));
 493   int Res = 1;
 494   if (C && !C->containsError()) {
 495     SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
 496     Res = TheDriver.ExecuteCompilation(*C, FailingCommands);
 497
 498     // Force a crash to test the diagnostics.
 499     if (TheDriver.GenReproducer) {
 500       Diags.Report(diag::err_drv_force_crash)
 501         << !::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH");
 502
 503       // Pretend that every command failed.
 504       FailingCommands.clear();
 505       for (const auto &J : C->getJobs())
 506         if (const Command *C = dyn_cast<Command>(&J))
 507           FailingCommands.push_back(std::make_pair(-1, C));
 508     }
 509
 510     for (const auto &P : FailingCommands) {
 511       int CommandRes = P.first;
 512       const Command *FailingCommand = P.second;
 513       if (!Res)
 514         Res = CommandRes;
 515
 516       // If result status is < 0, then the driver command signalled an error.
 517       // If result status is 70, then the driver command reported a fatal error.
 518       // On Windows, abort will return an exit code of 3.  In these cases,
 519       // generate additional diagnostic information if possible.
 520       bool DiagnoseCrash = CommandRes < 0 || CommandRes == 70;
 521 #ifdef _WIN32
 522       DiagnoseCrash |= CommandRes == 3;
 523 #endif
 524       if (DiagnoseCrash) {
 525         TheDriver.generateCompilationDiagnostics(*C, *FailingCommand);
 526         break;
 527       }
 528     }
 529   }
 530
 531   Diags.getClient()->finish();
 532
 533   // If any timers were active but haven't been destroyed yet, print their
 534   // results now.  This happens in -disable-free mode.
 535   llvm::TimerGroup::printAll(llvm::errs());
 536   llvm::TimerGroup::clearAll();
 537
 538 #ifdef _WIN32
 539   // Exit status should not be negative on Win32, unless abnormal termination.
 540   // Once abnormal termination was caught, negative status should not be
 541   // propagated.
 542   if (Res < 0)
 543     Res = 1;
 544 #endif
 545
 546   // If we have multiple failing commands, we return the result of the first
 547   // failing command.
 548   return Res;
 549 }