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 bool TimePasses = Clang->getCodeGenOpts().TimePasses; 287 if (TimePasses) 288 Clang->createFrontendTimer(); 289 llvm::TimeRegion Timer(TimePasses ? &Clang->getFrontendTimer() : nullptr); 290 Success = ExecuteCompilerInvocation(Clang.get()); 291 } 292 293 // If any timers were active but haven't been destroyed yet, print their 294 // results now. This happens in -disable-free mode. 295 llvm::TimerGroup::printAll(llvm::errs()); 296 llvm::TimerGroup::clearAll(); 297 298 if (llvm::timeTraceProfilerEnabled()) { 299 // It is possible that the compiler instance doesn't own a file manager here 300 // if we're compiling a module unit. Since the file manager are owned by AST 301 // when we're compiling a module unit. So the file manager may be invalid 302 // here. 303 // 304 // It should be fine to create file manager here since the file system 305 // options are stored in the compiler invocation and we can recreate the VFS 306 // from the compiler invocation. 307 if (!Clang->hasFileManager()) 308 Clang->createFileManager(createVFSFromCompilerInvocation( 309 Clang->getInvocation(), Clang->getDiagnostics())); 310 311 if (auto profilerOutput = Clang->createOutputFile( 312 Clang->getFrontendOpts().TimeTracePath, /*Binary=*/false, 313 /*RemoveFileOnSignal=*/false, 314 /*useTemporary=*/false)) { 315 llvm::timeTraceProfilerWrite(*profilerOutput); 316 profilerOutput.reset(); 317 llvm::timeTraceProfilerCleanup(); 318 Clang->clearOutputFiles(false); 319 } 320 } 321 322 // Our error handler depends on the Diagnostics object, which we're 323 // potentially about to delete. Uninstall the handler now so that any 324 // later errors use the default handling behavior instead. 325 llvm::remove_fatal_error_handler(); 326 327 // When running with -disable-free, don't do any destruction or shutdown. 328 if (Clang->getFrontendOpts().DisableFree) { 329 llvm::BuryPointer(std::move(Clang)); 330 return !Success; 331 } 332 333 return !Success; 334 } 335