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/HeaderInclude.h"
  17 #include "clang/Basic/Stack.h"
  18 #include "clang/Config/config.h"
  19 #include "clang/Driver/Compilation.h"
  20 #include "clang/Driver/DriverDiagnostic.h"
  21 #include "clang/Driver/Options.h"
  22 #include "clang/Driver/ToolChain.h"
  23 #include "clang/Frontend/ChainedDiagnosticConsumer.h"
  24 #include "clang/Frontend/CompilerInvocation.h"
  25 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
  26 #include "clang/Frontend/TextDiagnosticPrinter.h"
  27 #include "clang/Frontend/Utils.h"
  28 #include "llvm/ADT/ArrayRef.h"
  29 #include "llvm/ADT/SmallString.h"
  30 #include "llvm/ADT/SmallVector.h"
  31 #include "llvm/ADT/StringSet.h"
  32 #include "llvm/Config/llvm-config.h" // for LLVM_ON_UNIX
  33 #include "llvm/Option/ArgList.h"
  34 #include "llvm/Option/OptTable.h"
  35 #include "llvm/Option/Option.h"
  36 #include "llvm/Support/BuryPointer.h"
  37 #include "llvm/Support/CommandLine.h"
  38 #include "llvm/Support/CrashRecoveryContext.h"
  39 #include "llvm/Support/ErrorHandling.h"
  40 #include "llvm/Support/FileSystem.h"
  41 #include "llvm/Support/LLVMDriver.h"
  42 #include "llvm/Support/Path.h"
  43 #include "llvm/Support/PrettyStackTrace.h"
  44 #include "llvm/Support/Process.h"
  45 #include "llvm/Support/Program.h"
  46 #include "llvm/Support/Signals.h"
  47 #include "llvm/Support/StringSaver.h"
  48 #include "llvm/Support/TargetSelect.h"
  49 #include "llvm/Support/Timer.h"
  50 #include "llvm/Support/VirtualFileSystem.h"
  51 #include "llvm/Support/raw_ostream.h"
  52 #include "llvm/TargetParser/Host.h"
  53 #include <memory>
  54 #include <optional>
  55 #include <set>
  56 #include <system_error>
  57
  58 using namespace clang;
  59 using namespace clang::driver;
  60 using namespace llvm::opt;
  61
  62 std::string GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
  63   if (!CanonicalPrefixes) {
  64     SmallString<128> ExecutablePath(Argv0);
  65     // Do a PATH lookup if Argv0 isn't a valid path.
  66     if (!llvm::sys::fs::exists(ExecutablePath))
  67       if (llvm::ErrorOr<std::string> P =
  68               llvm::sys::findProgramByName(ExecutablePath))
  69         ExecutablePath = *P;
  70     return std::string(ExecutablePath);
  71   }
  72
  73   // This just needs to be some symbol in the binary; C++ doesn't
  74   // allow taking the address of ::main however.
  75   void *P = (void*) (intptr_t) GetExecutablePath;
  76   return llvm::sys::fs::getMainExecutable(Argv0, P);
  77 }
  78
  79 static const char *GetStableCStr(llvm::StringSet<> &SavedStrings, StringRef S) {
  80   return SavedStrings.insert(S).first->getKeyData();
  81 }
  82
  83 extern int cc1_main(ArrayRef<const char *> Argv, const char *Argv0,
  84                     void *MainAddr);
  85 extern int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0,
  86                       void *MainAddr);
  87 extern int cc1gen_reproducer_main(ArrayRef<const char *> Argv,
  88                                   const char *Argv0, void *MainAddr,
  89                                   const llvm::ToolContext &);
  90
  91 static void insertTargetAndModeArgs(const ParsedClangName &NameParts,
  92                                     SmallVectorImpl<const char *> &ArgVector,
  93                                     llvm::StringSet<> &SavedStrings) {
  94   // Put target and mode arguments at the start of argument list so that
  95   // arguments specified in command line could override them. Avoid putting
  96   // them at index 0, as an option like '-cc1' must remain the first.
  97   int InsertionPoint = 0;
  98   if (ArgVector.size() > 0)
  99     ++InsertionPoint;
 100
 101   if (NameParts.DriverMode) {
 102     // Add the mode flag to the arguments.
 103     ArgVector.insert(ArgVector.begin() + InsertionPoint,
 104                      GetStableCStr(SavedStrings, NameParts.DriverMode));
 105   }
 106
 107   if (NameParts.TargetIsValid) {
 108     const char *arr[] = {"-target", GetStableCStr(SavedStrings,
 109                                                   NameParts.TargetPrefix)};
 110     ArgVector.insert(ArgVector.begin() + InsertionPoint,
 111                      std::begin(arr), std::end(arr));
 112   }
 113 }
 114
 115 static void getCLEnvVarOptions(std::string &EnvValue, llvm::StringSaver &Saver,
 116                                SmallVectorImpl<const char *> &Opts) {
 117   llvm::cl::TokenizeWindowsCommandLine(EnvValue, Saver, Opts);
 118   // The first instance of '#' should be replaced with '=' in each option.
 119   for (const char *Opt : Opts)
 120     if (char *NumberSignPtr = const_cast<char *>(::strchr(Opt, '#')))
 121       *NumberSignPtr = '=';
 122 }
 123
 124 template <class T>
 125 static T checkEnvVar(const char *EnvOptSet, const char *EnvOptFile,
 126                      std::string &OptFile) {
 127   const char *Str = ::getenv(EnvOptSet);
 128   if (!Str)
 129     return T{};
 130
 131   T OptVal = Str;
 132   if (const char *Var = ::getenv(EnvOptFile))
 133     OptFile = Var;
 134   return OptVal;
 135 }
 136
 137 static bool SetBackdoorDriverOutputsFromEnvVars(Driver &TheDriver) {
 138   TheDriver.CCPrintOptions =
 139       checkEnvVar<bool>("CC_PRINT_OPTIONS", "CC_PRINT_OPTIONS_FILE",
 140                         TheDriver.CCPrintOptionsFilename);
 141   if (checkEnvVar<bool>("CC_PRINT_HEADERS", "CC_PRINT_HEADERS_FILE",
 142                         TheDriver.CCPrintHeadersFilename)) {
 143     TheDriver.CCPrintHeadersFormat = HIFMT_Textual;
 144     TheDriver.CCPrintHeadersFiltering = HIFIL_None;
 145   } else {
 146     std::string EnvVar = checkEnvVar<std::string>(
 147         "CC_PRINT_HEADERS_FORMAT", "CC_PRINT_HEADERS_FILE",
 148         TheDriver.CCPrintHeadersFilename);
 149     if (!EnvVar.empty()) {
 150       TheDriver.CCPrintHeadersFormat =
 151           stringToHeaderIncludeFormatKind(EnvVar.c_str());
 152       if (!TheDriver.CCPrintHeadersFormat) {
 153         TheDriver.Diag(clang::diag::err_drv_print_header_env_var)
 154             << 0 << EnvVar;
 155         return false;
 156       }
 157
 158       const char *FilteringStr = ::getenv("CC_PRINT_HEADERS_FILTERING");
 159       HeaderIncludeFilteringKind Filtering;
 160       if (!stringToHeaderIncludeFiltering(FilteringStr, Filtering)) {
 161         TheDriver.Diag(clang::diag::err_drv_print_header_env_var)
 162             << 1 << FilteringStr;
 163         return false;
 164       }
 165
 166       if ((TheDriver.CCPrintHeadersFormat == HIFMT_Textual &&
 167            Filtering != HIFIL_None) ||
 168           (TheDriver.CCPrintHeadersFormat == HIFMT_JSON &&
 169            Filtering != HIFIL_Only_Direct_System)) {
 170         TheDriver.Diag(clang::diag::err_drv_print_header_env_var_combination)
 171             << EnvVar << FilteringStr;
 172         return false;
 173       }
 174       TheDriver.CCPrintHeadersFiltering = Filtering;
 175     }
 176   }
 177
 178   TheDriver.CCLogDiagnostics =
 179       checkEnvVar<bool>("CC_LOG_DIAGNOSTICS", "CC_LOG_DIAGNOSTICS_FILE",
 180                         TheDriver.CCLogDiagnosticsFilename);
 181   TheDriver.CCPrintProcessStats =
 182       checkEnvVar<bool>("CC_PRINT_PROC_STAT", "CC_PRINT_PROC_STAT_FILE",
 183                         TheDriver.CCPrintStatReportFilename);
 184   TheDriver.CCPrintInternalStats =
 185       checkEnvVar<bool>("CC_PRINT_INTERNAL_STAT", "CC_PRINT_INTERNAL_STAT_FILE",
 186                         TheDriver.CCPrintInternalStatReportFilename);
 187
 188   return true;
 189 }
 190
 191 static void FixupDiagPrefixExeName(TextDiagnosticPrinter *DiagClient,
 192                                    const std::string &Path) {
 193   // If the clang binary happens to be named cl.exe for compatibility reasons,
 194   // use clang-cl.exe as the prefix to avoid confusion between clang and MSVC.
 195   StringRef ExeBasename(llvm::sys::path::stem(Path));
 196   if (ExeBasename.equals_insensitive("cl"))
 197     ExeBasename = "clang-cl";
 198   DiagClient->setPrefix(std::string(ExeBasename));
 199 }
 200
 201 static int ExecuteCC1Tool(SmallVectorImpl<const char *> &ArgV,
 202                           const llvm::ToolContext &ToolContext) {
 203   // If we call the cc1 tool from the clangDriver library (through
 204   // Driver::CC1Main), we need to clean up the options usage count. The options
 205   // are currently global, and they might have been used previously by the
 206   // driver.
 207   llvm::cl::ResetAllOptionOccurrences();
 208
 209   llvm::BumpPtrAllocator A;
 210   llvm::cl::ExpansionContext ECtx(A, llvm::cl::TokenizeGNUCommandLine);
 211   if (llvm::Error Err = ECtx.expandResponseFiles(ArgV)) {
 212     llvm::errs() << toString(std::move(Err)) << '\n';
 213     return 1;
 214   }
 215   StringRef Tool = ArgV[1];
 216   void *GetExecutablePathVP = (void *)(intptr_t)GetExecutablePath;
 217   if (Tool == "-cc1")
 218     return cc1_main(ArrayRef(ArgV).slice(1), ArgV[0], GetExecutablePathVP);
 219   if (Tool == "-cc1as")
 220     return cc1as_main(ArrayRef(ArgV).slice(2), ArgV[0], GetExecutablePathVP);
 221   if (Tool == "-cc1gen-reproducer")
 222     return cc1gen_reproducer_main(ArrayRef(ArgV).slice(2), ArgV[0],
 223                                   GetExecutablePathVP, ToolContext);
 224   // Reject unknown tools.
 225   llvm::errs()
 226       << "error: unknown integrated tool '" << Tool << "'. "
 227       << "Valid tools include '-cc1', '-cc1as' and '-cc1gen-reproducer'.\n";
 228   return 1;
 229 }
 230
 231 int clang_main(int Argc, char **Argv, const llvm::ToolContext &ToolContext) {
 232   noteBottomOfStack();
 233   llvm::setBugReportMsg("PLEASE submit a bug report to " BUG_REPORT_URL
 234                         " and include the crash backtrace, preprocessed "
 235                         "source, and associated run script.\n");
 236   SmallVector<const char *, 256> Args(Argv, Argv + Argc);
 237
 238   if (llvm::sys::Process::FixupStandardFileDescriptors())
 239     return 1;
 240
 241   llvm::InitializeAllTargets();
 242
 243   llvm::BumpPtrAllocator A;
 244   llvm::StringSaver Saver(A);
 245
 246   const char *ProgName =
 247       ToolContext.NeedsPrependArg ? ToolContext.PrependArg : ToolContext.Path;
 248
 249   bool ClangCLMode =
 250       IsClangCL(getDriverMode(ProgName, llvm::ArrayRef(Args).slice(1)));
 251
 252   if (llvm::Error Err = expandResponseFiles(Args, ClangCLMode, A)) {
 253     llvm::errs() << toString(std::move(Err)) << '\n';
 254     return 1;
 255   }
 256
 257   // Handle -cc1 integrated tools.
 258   if (Args.size() >= 2 && StringRef(Args[1]).starts_with("-cc1"))
 259     return ExecuteCC1Tool(Args, ToolContext);
 260
 261   // Handle options that need handling before the real command line parsing in
 262   // Driver::BuildCompilation()
 263   bool CanonicalPrefixes = true;
 264   for (int i = 1, size = Args.size(); i < size; ++i) {
 265     // Skip end-of-line response file markers
 266     if (Args[i] == nullptr)
 267       continue;
 268     if (StringRef(Args[i]) == "-canonical-prefixes")
 269       CanonicalPrefixes = true;
 270     else if (StringRef(Args[i]) == "-no-canonical-prefixes")
 271       CanonicalPrefixes = false;
 272   }
 273
 274   // Handle CL and _CL_ which permits additional command line options to be
 275   // prepended or appended.
 276   if (ClangCLMode) {
 277     // Arguments in "CL" are prepended.
 278     std::optional<std::string> OptCL = llvm::sys::Process::GetEnv("CL");
 279     if (OptCL) {
 280       SmallVector<const char *, 8> PrependedOpts;
 281       getCLEnvVarOptions(*OptCL, Saver, PrependedOpts);
 282
 283       // Insert right after the program name to prepend to the argument list.
 284       Args.insert(Args.begin() + 1, PrependedOpts.begin(), PrependedOpts.end());
 285     }
 286     // Arguments in "_CL_" are appended.
 287     std::optional<std::string> Opt_CL_ = llvm::sys::Process::GetEnv("_CL_");
 288     if (Opt_CL_) {
 289       SmallVector<const char *, 8> AppendedOpts;
 290       getCLEnvVarOptions(*Opt_CL_, Saver, AppendedOpts);
 291
 292       // Insert at the end of the argument list to append.
 293       Args.append(AppendedOpts.begin(), AppendedOpts.end());
 294     }
 295   }
 296
 297   llvm::StringSet<> SavedStrings;
 298   // Handle CCC_OVERRIDE_OPTIONS, used for editing a command line behind the
 299   // scenes.
 300   if (const char *OverrideStr = ::getenv("CCC_OVERRIDE_OPTIONS")) {
 301     // FIXME: Driver shouldn't take extra initial argument.
 302     driver::applyOverrideOptions(Args, OverrideStr, SavedStrings,
 303                                  &llvm::errs());
 304   }
 305
 306   std::string Path = GetExecutablePath(ToolContext.Path, CanonicalPrefixes);
 307
 308   // Whether the cc1 tool should be called inside the current process, or if we
 309   // should spawn a new clang subprocess (old behavior).
 310   // Not having an additional process saves some execution time of Windows,
 311   // and makes debugging and profiling easier.
 312   bool UseNewCC1Process = CLANG_SPAWN_CC1;
 313   for (const char *Arg : Args)
 314     UseNewCC1Process = llvm::StringSwitch<bool>(Arg)
 315                            .Case("-fno-integrated-cc1", true)
 316                            .Case("-fintegrated-cc1", false)
 317                            .Default(UseNewCC1Process);
 318
 319   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =
 320       CreateAndPopulateDiagOpts(Args);
 321
 322   TextDiagnosticPrinter *DiagClient
 323     = new TextDiagnosticPrinter(llvm::errs(), &*DiagOpts);
 324   FixupDiagPrefixExeName(DiagClient, ProgName);
 325
 326   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
 327
 328   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
 329
 330   if (!DiagOpts->DiagnosticSerializationFile.empty()) {
 331     auto SerializedConsumer =
 332         clang::serialized_diags::create(DiagOpts->DiagnosticSerializationFile,
 333                                         &*DiagOpts, /*MergeChildRecords=*/true);
 334     Diags.setClient(new ChainedDiagnosticConsumer(
 335         Diags.takeClient(), std::move(SerializedConsumer)));
 336   }
 337
 338   auto VFS = llvm::vfs::getRealFileSystem();
 339   ProcessWarningOptions(Diags, *DiagOpts, *VFS, /*ReportDiags=*/false);
 340
 341   Driver TheDriver(Path, llvm::sys::getDefaultTargetTriple(), Diags,
 342                    /*Title=*/"clang LLVM compiler", VFS);
 343   auto TargetAndMode = ToolChain::getTargetAndModeFromProgramName(ProgName);
 344   TheDriver.setTargetAndMode(TargetAndMode);
 345   // If -canonical-prefixes is set, GetExecutablePath will have resolved Path
 346   // to the llvm driver binary, not clang. In this case, we need to use
 347   // PrependArg which should be clang-*. Checking just CanonicalPrefixes is
 348   // safe even in the normal case because PrependArg will be null so
 349   // setPrependArg will be a no-op.
 350   if (ToolContext.NeedsPrependArg || CanonicalPrefixes)
 351     TheDriver.setPrependArg(ToolContext.PrependArg);
 352
 353   insertTargetAndModeArgs(TargetAndMode, Args, SavedStrings);
 354
 355   if (!SetBackdoorDriverOutputsFromEnvVars(TheDriver))
 356     return 1;
 357
 358   if (!UseNewCC1Process) {
 359     TheDriver.CC1Main = [ToolContext](SmallVectorImpl<const char *> &ArgV) {
 360       return ExecuteCC1Tool(ArgV, ToolContext);
 361     };
 362     // Ensure the CC1Command actually catches cc1 crashes
 363     llvm::CrashRecoveryContext::Enable();
 364   }
 365
 366   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(Args));
 367
 368   Driver::ReproLevel ReproLevel = Driver::ReproLevel::OnCrash;
 369   if (Arg *A = C->getArgs().getLastArg(options::OPT_gen_reproducer_eq)) {
 370     auto Level =
 371         llvm::StringSwitch<std::optional<Driver::ReproLevel>>(A->getValue())
 372             .Case("off", Driver::ReproLevel::Off)
 373             .Case("crash", Driver::ReproLevel::OnCrash)
 374             .Case("error", Driver::ReproLevel::OnError)
 375             .Case("always", Driver::ReproLevel::Always)
 376             .Default(std::nullopt);
 377     if (!Level) {
 378       llvm::errs() << "Unknown value for " << A->getSpelling() << ": '"
 379                    << A->getValue() << "'\n";
 380       return 1;
 381     }
 382     ReproLevel = *Level;
 383   }
 384   if (!!::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))
 385     ReproLevel = Driver::ReproLevel::Always;
 386
 387   int Res = 1;
 388   bool IsCrash = false;
 389   Driver::CommandStatus CommandStatus = Driver::CommandStatus::Ok;
 390   // Pretend the first command failed if ReproStatus is Always.
 391   const Command *FailingCommand = nullptr;
 392   if (!C->getJobs().empty())
 393     FailingCommand = &*C->getJobs().begin();
 394   if (C && !C->containsError()) {
 395     SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
 396     Res = TheDriver.ExecuteCompilation(*C, FailingCommands);
 397
 398     for (const auto &P : FailingCommands) {
 399       int CommandRes = P.first;
 400       FailingCommand = P.second;
 401       if (!Res)
 402         Res = CommandRes;
 403
 404       // If result status is < 0, then the driver command signalled an error.
 405       // If result status is 70, then the driver command reported a fatal error.
 406       // On Windows, abort will return an exit code of 3.  In these cases,
 407       // generate additional diagnostic information if possible.
 408       IsCrash = CommandRes < 0 || CommandRes == 70;
 409 #ifdef _WIN32
 410       IsCrash |= CommandRes == 3;
 411 #endif
 412 #if LLVM_ON_UNIX
 413       // When running in integrated-cc1 mode, the CrashRecoveryContext returns
 414       // the same codes as if the program crashed. See section "Exit Status for
 415       // Commands":
 416       // https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu_chap02.html
 417       IsCrash |= CommandRes > 128;
 418 #endif
 419       CommandStatus =
 420           IsCrash ? Driver::CommandStatus::Crash : Driver::CommandStatus::Error;
 421       if (IsCrash)
 422         break;
 423     }
 424   }
 425
 426   // Print the bug report message that would be printed if we did actually
 427   // crash, but only if we're crashing due to FORCE_CLANG_DIAGNOSTICS_CRASH.
 428   if (::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))
 429     llvm::dbgs() << llvm::getBugReportMsg();
 430   if (FailingCommand != nullptr &&
 431     TheDriver.maybeGenerateCompilationDiagnostics(CommandStatus, ReproLevel,
 432                                                   *C, *FailingCommand))
 433     Res = 1;
 434
 435   Diags.getClient()->finish();
 436
 437   if (!UseNewCC1Process && IsCrash) {
 438     // When crashing in -fintegrated-cc1 mode, bury the timer pointers, because
 439     // the internal linked list might point to already released stack frames.
 440     llvm::BuryPointer(llvm::TimerGroup::aquireDefaultGroup());
 441   } else {
 442     // If any timers were active but haven't been destroyed yet, print their
 443     // results now.  This happens in -disable-free mode.
 444     llvm::TimerGroup::printAll(llvm::errs());
 445     llvm::TimerGroup::clearAll();
 446   }
 447
 448 #ifdef _WIN32
 449   // Exit status should not be negative on Win32, unless abnormal termination.
 450   // Once abnormal termination was caught, negative status should not be
 451   // propagated.
 452   if (Res < 0)
 453     Res = 1;
 454 #endif
 455
 456   // If we have multiple failing commands, we return the result of the first
 457   // failing command.
 458   return Res;
 459 }