clang/tools/driver/cc1_main.cpp

   1 //===-- cc1_main.cpp - Clang CC1 Compiler Frontend ------------------------===//
   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 -cc1 functionality, which implements the
  10 // core compiler functionality along with a number of additional tools for
  11 // demonstration and testing purposes.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "clang/Basic/Stack.h"
  16 #include "clang/Basic/TargetOptions.h"
  17 #include "clang/CodeGen/ObjectFilePCHContainerWriter.h"
  18 #include "clang/Config/config.h"
  19 #include "clang/Driver/DriverDiagnostic.h"
  20 #include "clang/Driver/Options.h"
  21 #include "clang/Frontend/CompilerInstance.h"
  22 #include "clang/Frontend/CompilerInvocation.h"
  23 #include "clang/Frontend/FrontendDiagnostic.h"
  24 #include "clang/Frontend/TextDiagnosticBuffer.h"
  25 #include "clang/Frontend/TextDiagnosticPrinter.h"
  26 #include "clang/Frontend/Utils.h"
  27 #include "clang/FrontendTool/Utils.h"
  28 #include "clang/Serialization/ObjectFilePCHContainerReader.h"
  29 #include "llvm/ADT/Statistic.h"
  30 #include "llvm/ADT/StringExtras.h"
  31 #include "llvm/Config/llvm-config.h"
  32 #include "llvm/LinkAllPasses.h"
  33 #include "llvm/MC/MCSubtargetInfo.h"
  34 #include "llvm/MC/TargetRegistry.h"
  35 #include "llvm/Option/Arg.h"
  36 #include "llvm/Option/ArgList.h"
  37 #include "llvm/Option/OptTable.h"
  38 #include "llvm/Support/BuryPointer.h"
  39 #include "llvm/Support/Compiler.h"
  40 #include "llvm/Support/ErrorHandling.h"
  41 #include "llvm/Support/ManagedStatic.h"
  42 #include "llvm/Support/Path.h"
  43 #include "llvm/Support/Process.h"
  44 #include "llvm/Support/Signals.h"
  45 #include "llvm/Support/TargetSelect.h"
  46 #include "llvm/Support/TimeProfiler.h"
  47 #include "llvm/Support/Timer.h"
  48 #include "llvm/Support/VirtualFileSystem.h"
  49 #include "llvm/Support/raw_ostream.h"
  50 #include "llvm/Target/TargetMachine.h"
  51 #include "llvm/TargetParser/AArch64TargetParser.h"
  52 #include "llvm/TargetParser/ARMTargetParser.h"
  53 #include "llvm/TargetParser/RISCVISAInfo.h"
  54 #include <cstdio>
  55
  56 #ifdef CLANG_HAVE_RLIMITS
  57 #include <sys/resource.h>
  58 #endif
  59
  60 using namespace clang;
  61 using namespace llvm::opt;
  62
  63 //===----------------------------------------------------------------------===//
  64 // Main driver
  65 //===----------------------------------------------------------------------===//
  66
  67 static void LLVMErrorHandler(void *UserData, const char *Message,
  68                              bool GenCrashDiag) {
  69   DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
  70
  71   Diags.Report(diag::err_fe_error_backend) << Message;
  72
  73   // Run the interrupt handlers to make sure any special cleanups get done, in
  74   // particular that we remove files registered with RemoveFileOnSignal.
  75   llvm::sys::RunInterruptHandlers();
  76
  77   // We cannot recover from llvm errors.  When reporting a fatal error, exit
  78   // with status 70 to generate crash diagnostics.  For BSD systems this is
  79   // defined as an internal software error.  Otherwise, exit with status 1.
  80   llvm::sys::Process::Exit(GenCrashDiag ? 70 : 1);
  81 }
  82
  83 #ifdef CLANG_HAVE_RLIMITS
  84 /// Attempt to ensure that we have at least 8MiB of usable stack space.
  85 static void ensureSufficientStack() {
  86   struct rlimit rlim;
  87   if (getrlimit(RLIMIT_STACK, &rlim) != 0)
  88     return;
  89
  90   // Increase the soft stack limit to our desired level, if necessary and
  91   // possible.
  92   if (rlim.rlim_cur != RLIM_INFINITY &&
  93       rlim.rlim_cur < rlim_t(DesiredStackSize)) {
  94     // Try to allocate sufficient stack.
  95     if (rlim.rlim_max == RLIM_INFINITY ||
  96         rlim.rlim_max >= rlim_t(DesiredStackSize))
  97       rlim.rlim_cur = DesiredStackSize;
  98     else if (rlim.rlim_cur == rlim.rlim_max)
  99       return;
 100     else
 101       rlim.rlim_cur = rlim.rlim_max;
 102
 103     if (setrlimit(RLIMIT_STACK, &rlim) != 0 ||
 104         rlim.rlim_cur != DesiredStackSize)
 105       return;
 106   }
 107 }
 108 #else
 109 static void ensureSufficientStack() {}
 110 #endif
 111
 112 /// Print supported cpus of the given target.
 113 static int PrintSupportedCPUs(std::string TargetStr) {
 114   std::string Error;
 115   const llvm::Target *TheTarget =
 116       llvm::TargetRegistry::lookupTarget(TargetStr, Error);
 117   if (!TheTarget) {
 118     llvm::errs() << Error;
 119     return 1;
 120   }
 121
 122   // the target machine will handle the mcpu printing
 123   llvm::TargetOptions Options;
 124   std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
 125       TheTarget->createTargetMachine(TargetStr, "", "+cpuhelp", Options,
 126                                      std::nullopt));
 127   return 0;
 128 }
 129
 130 static int PrintSupportedExtensions(std::string TargetStr) {
 131   std::string Error;
 132   const llvm::Target *TheTarget =
 133       llvm::TargetRegistry::lookupTarget(TargetStr, Error);
 134   if (!TheTarget) {
 135     llvm::errs() << Error;
 136     return 1;
 137   }
 138
 139   llvm::TargetOptions Options;
 140   std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
 141       TheTarget->createTargetMachine(TargetStr, "", "", Options, std::nullopt));
 142   const llvm::Triple &MachineTriple = TheTargetMachine->getTargetTriple();
 143   const llvm::MCSubtargetInfo *MCInfo = TheTargetMachine->getMCSubtargetInfo();
 144   const llvm::ArrayRef<llvm::SubtargetFeatureKV> Features =
 145     MCInfo->getAllProcessorFeatures();
 146
 147   llvm::StringMap<llvm::StringRef> DescMap;
 148   for (const llvm::SubtargetFeatureKV &feature : Features)
 149     DescMap.insert({feature.Key, feature.Desc});
 150
 151   if (MachineTriple.isRISCV())
 152     llvm::RISCVISAInfo::printSupportedExtensions(DescMap);
 153   else if (MachineTriple.isAArch64())
 154     llvm::AArch64::PrintSupportedExtensions();
 155   else if (MachineTriple.isARM())
 156     llvm::ARM::PrintSupportedExtensions(DescMap);
 157   else {
 158     // The option was already checked in Driver::HandleImmediateArgs,
 159     // so we do not expect to get here if we are not a supported architecture.
 160     assert(0 && "Unhandled triple for --print-supported-extensions option.");
 161     return 1;
 162   }
 163
 164   return 0;
 165 }
 166
 167 static int PrintEnabledExtensions(const TargetOptions& TargetOpts) {
 168   std::string Error;
 169   const llvm::Target *TheTarget =
 170       llvm::TargetRegistry::lookupTarget(TargetOpts.Triple, Error);
 171   if (!TheTarget) {
 172     llvm::errs() << Error;
 173     return 1;
 174   }
 175
 176   // Create a target machine using the input features, the triple information
 177   // and a dummy instance of llvm::TargetOptions. Note that this is _not_ the
 178   // same as the `clang::TargetOptions` instance we have access to here.
 179   llvm::TargetOptions BackendOptions;
 180   std::string FeaturesStr = llvm::join(TargetOpts.FeaturesAsWritten, ",");
 181   std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
 182       TheTarget->createTargetMachine(TargetOpts.Triple, TargetOpts.CPU, FeaturesStr, BackendOptions, std::nullopt));
 183   const llvm::Triple &MachineTriple = TheTargetMachine->getTargetTriple();
 184   const llvm::MCSubtargetInfo *MCInfo = TheTargetMachine->getMCSubtargetInfo();
 185
 186   // Extract the feature names that are enabled for the given target.
 187   // We do that by capturing the key from the set of SubtargetFeatureKV entries
 188   // provided by MCSubtargetInfo, which match the '-target-feature' values.
 189   const std::vector<llvm::SubtargetFeatureKV> Features =
 190     MCInfo->getEnabledProcessorFeatures();
 191   std::set<llvm::StringRef> EnabledFeatureNames;
 192   for (const llvm::SubtargetFeatureKV &feature : Features)
 193     EnabledFeatureNames.insert(feature.Key);
 194
 195   if (MachineTriple.isAArch64())
 196     llvm::AArch64::printEnabledExtensions(EnabledFeatureNames);
 197   else if (MachineTriple.isRISCV()) {
 198     llvm::StringMap<llvm::StringRef> DescMap;
 199     for (const llvm::SubtargetFeatureKV &feature : Features)
 200       DescMap.insert({feature.Key, feature.Desc});
 201     llvm::RISCVISAInfo::printEnabledExtensions(MachineTriple.isArch64Bit(),
 202                                                EnabledFeatureNames, DescMap);
 203   } else {
 204     // The option was already checked in Driver::HandleImmediateArgs,
 205     // so we do not expect to get here if we are not a supported architecture.
 206     assert(0 && "Unhandled triple for --print-enabled-extensions option.");
 207     return 1;
 208   }
 209
 210   return 0;
 211 }
 212
 213 int cc1_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
 214   ensureSufficientStack();
 215
 216   std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
 217   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
 218
 219   // Register the support for object-file-wrapped Clang modules.
 220   auto PCHOps = Clang->getPCHContainerOperations();
 221   PCHOps->registerWriter(std::make_unique<ObjectFilePCHContainerWriter>());
 222   PCHOps->registerReader(std::make_unique<ObjectFilePCHContainerReader>());
 223
 224   // Initialize targets first, so that --version shows registered targets.
 225   llvm::InitializeAllTargets();
 226   llvm::InitializeAllTargetMCs();
 227   llvm::InitializeAllAsmPrinters();
 228   llvm::InitializeAllAsmParsers();
 229
 230   // Buffer diagnostics from argument parsing so that we can output them using a
 231   // well formed diagnostic object.
 232   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
 233   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
 234   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagsBuffer);
 235
 236   // Setup round-trip remarks for the DiagnosticsEngine used in CreateFromArgs.
 237   if (find(Argv, StringRef("-Rround-trip-cc1-args")) != Argv.end())
 238     Diags.setSeverity(diag::remark_cc1_round_trip_generated,
 239                       diag::Severity::Remark, {});
 240
 241   bool Success = CompilerInvocation::CreateFromArgs(Clang->getInvocation(),
 242                                                     Argv, Diags, Argv0);
 243
 244   if (!Clang->getFrontendOpts().TimeTracePath.empty()) {
 245     llvm::timeTraceProfilerInitialize(
 246         Clang->getFrontendOpts().TimeTraceGranularity, Argv0,
 247         Clang->getFrontendOpts().TimeTraceVerbose);
 248   }
 249   // --print-supported-cpus takes priority over the actual compilation.
 250   if (Clang->getFrontendOpts().PrintSupportedCPUs)
 251     return PrintSupportedCPUs(Clang->getTargetOpts().Triple);
 252
 253   // --print-supported-extensions takes priority over the actual compilation.
 254   if (Clang->getFrontendOpts().PrintSupportedExtensions)
 255     return PrintSupportedExtensions(Clang->getTargetOpts().Triple);
 256
 257   // --print-enabled-extensions takes priority over the actual compilation.
 258   if (Clang->getFrontendOpts().PrintEnabledExtensions)
 259     return PrintEnabledExtensions(Clang->getTargetOpts());
 260
 261   // Infer the builtin include path if unspecified.
 262   if (Clang->getHeaderSearchOpts().UseBuiltinIncludes &&
 263       Clang->getHeaderSearchOpts().ResourceDir.empty())
 264     Clang->getHeaderSearchOpts().ResourceDir =
 265       CompilerInvocation::GetResourcesPath(Argv0, MainAddr);
 266
 267   // Create the actual diagnostics engine.
 268   Clang->createDiagnostics(*llvm::vfs::getRealFileSystem());
 269   if (!Clang->hasDiagnostics())
 270     return 1;
 271
 272   // Set an error handler, so that any LLVM backend diagnostics go through our
 273   // error handler.
 274   llvm::install_fatal_error_handler(LLVMErrorHandler,
 275                                   static_cast<void*>(&Clang->getDiagnostics()));
 276
 277   DiagsBuffer->FlushDiagnostics(Clang->getDiagnostics());
 278   if (!Success) {
 279     Clang->getDiagnosticClient().finish();
 280     return 1;
 281   }
 282
 283   // Execute the frontend actions.
 284   {
 285     llvm::TimeTraceScope TimeScope("ExecuteCompiler");
 286     Success = ExecuteCompilerInvocation(Clang.get());
 287   }
 288
 289   // If any timers were active but haven't been destroyed yet, print their
 290   // results now.  This happens in -disable-free mode.
 291   llvm::TimerGroup::printAll(llvm::errs());
 292   llvm::TimerGroup::clearAll();
 293
 294   if (llvm::timeTraceProfilerEnabled()) {
 295     // It is possible that the compiler instance doesn't own a file manager here
 296     // if we're compiling a module unit. Since the file manager are owned by AST
 297     // when we're compiling a module unit. So the file manager may be invalid
 298     // here.
 299     //
 300     // It should be fine to create file manager here since the file system
 301     // options are stored in the compiler invocation and we can recreate the VFS
 302     // from the compiler invocation.
 303     if (!Clang->hasFileManager())
 304       Clang->createFileManager(createVFSFromCompilerInvocation(
 305           Clang->getInvocation(), Clang->getDiagnostics()));
 306
 307     if (auto profilerOutput = Clang->createOutputFile(
 308             Clang->getFrontendOpts().TimeTracePath, /*Binary=*/false,
 309             /*RemoveFileOnSignal=*/false,
 310             /*useTemporary=*/false)) {
 311       llvm::timeTraceProfilerWrite(*profilerOutput);
 312       profilerOutput.reset();
 313       llvm::timeTraceProfilerCleanup();
 314       Clang->clearOutputFiles(false);
 315     }
 316   }
 317
 318   // Our error handler depends on the Diagnostics object, which we're
 319   // potentially about to delete. Uninstall the handler now so that any
 320   // later errors use the default handling behavior instead.
 321   llvm::remove_fatal_error_handler();
 322
 323   // When running with -disable-free, don't do any destruction or shutdown.
 324   if (Clang->getFrontendOpts().DisableFree) {
 325     llvm::BuryPointer(std::move(Clang));
 326     return !Success;
 327   }
 328
 329   return !Success;
 330 }