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