1 //===-- FrontendAction.h - Generic Frontend Action Interface ----*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 /// 10 /// \file 11 /// \brief Defines the clang::FrontendAction interface and various convenience 12 /// abstract classes (clang::ASTFrontendAction, clang::PluginASTAction, 13 /// clang::PreprocessorFrontendAction, and clang::WrapperFrontendAction) 14 /// derived from it. 15 /// 16 //===----------------------------------------------------------------------===// 17 18 #ifndef LLVM_CLANG_FRONTEND_FRONTENDACTION_H 19 #define LLVM_CLANG_FRONTEND_FRONTENDACTION_H 20 21 #include "clang/AST/ASTConsumer.h" 22 #include "clang/Basic/LLVM.h" 23 #include "clang/Basic/LangOptions.h" 24 #include "clang/Frontend/ASTUnit.h" 25 #include "clang/Frontend/FrontendOptions.h" 26 #include "llvm/ADT/StringRef.h" 27 #include <memory> 28 #include <string> 29 #include <vector> 30 31 namespace clang { 32 class ASTMergeAction; 33 class CompilerInstance; 34 35 /// Abstract base class for actions which can be performed by the frontend. 36 class FrontendAction { 37 FrontendInputFile CurrentInput; 38 std::unique_ptr<ASTUnit> CurrentASTUnit; 39 CompilerInstance *Instance; 40 friend class ASTMergeAction; 41 friend class WrapperFrontendAction; 42 43 private: 44 std::unique_ptr<ASTConsumer> CreateWrappedASTConsumer(CompilerInstance &CI, 45 StringRef InFile); 46 47 protected: 48 /// @name Implementation Action Interface 49 /// @{ 50 51 /// \brief Create the AST consumer object for this action, if supported. 52 /// 53 /// This routine is called as part of BeginSourceFile(), which will 54 /// fail if the AST consumer cannot be created. This will not be called if the 55 /// action has indicated that it only uses the preprocessor. 56 /// 57 /// \param CI - The current compiler instance, provided as a convenience, see 58 /// getCompilerInstance(). 59 /// 60 /// \param InFile - The current input file, provided as a convenience, see 61 /// getCurrentFile(). 62 /// 63 /// \return The new AST consumer, or null on failure. 64 virtual std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI, 65 StringRef InFile) = 0; 66 67 /// \brief Callback before starting processing a single input, giving the 68 /// opportunity to modify the CompilerInvocation or do some other action 69 /// before BeginSourceFileAction is called. 70 /// 71 /// \return True on success; on failure BeginSourceFileAction(), 72 /// ExecuteAction() and EndSourceFileAction() will not be called. BeginInvocation(CompilerInstance & CI)73 virtual bool BeginInvocation(CompilerInstance &CI) { return true; } 74 75 /// \brief Callback at the start of processing a single input. 76 /// 77 /// \return True on success; on failure ExecutionAction() and 78 /// EndSourceFileAction() will not be called. BeginSourceFileAction(CompilerInstance & CI,StringRef Filename)79 virtual bool BeginSourceFileAction(CompilerInstance &CI, 80 StringRef Filename) { 81 return true; 82 } 83 84 /// \brief Callback to run the program action, using the initialized 85 /// compiler instance. 86 /// 87 /// This is guaranteed to only be called between BeginSourceFileAction() 88 /// and EndSourceFileAction(). 89 virtual void ExecuteAction() = 0; 90 91 /// \brief Callback at the end of processing a single input. 92 /// 93 /// This is guaranteed to only be called following a successful call to 94 /// BeginSourceFileAction (and BeginSourceFile). EndSourceFileAction()95 virtual void EndSourceFileAction() {} 96 97 /// \brief Callback at the end of processing a single input, to determine 98 /// if the output files should be erased or not. 99 /// 100 /// By default it returns true if a compiler error occurred. 101 /// This is guaranteed to only be called following a successful call to 102 /// BeginSourceFileAction (and BeginSourceFile). 103 virtual bool shouldEraseOutputFiles(); 104 105 /// @} 106 107 public: 108 FrontendAction(); 109 virtual ~FrontendAction(); 110 111 /// @name Compiler Instance Access 112 /// @{ 113 getCompilerInstance()114 CompilerInstance &getCompilerInstance() const { 115 assert(Instance && "Compiler instance not registered!"); 116 return *Instance; 117 } 118 setCompilerInstance(CompilerInstance * Value)119 void setCompilerInstance(CompilerInstance *Value) { Instance = Value; } 120 121 /// @} 122 /// @name Current File Information 123 /// @{ 124 isCurrentFileAST()125 bool isCurrentFileAST() const { 126 assert(!CurrentInput.isEmpty() && "No current file!"); 127 return (bool)CurrentASTUnit; 128 } 129 getCurrentInput()130 const FrontendInputFile &getCurrentInput() const { 131 return CurrentInput; 132 } 133 getCurrentFile()134 const StringRef getCurrentFile() const { 135 assert(!CurrentInput.isEmpty() && "No current file!"); 136 return CurrentInput.getFile(); 137 } 138 getCurrentFileKind()139 InputKind getCurrentFileKind() const { 140 assert(!CurrentInput.isEmpty() && "No current file!"); 141 return CurrentInput.getKind(); 142 } 143 getCurrentASTUnit()144 ASTUnit &getCurrentASTUnit() const { 145 assert(CurrentASTUnit && "No current AST unit!"); 146 return *CurrentASTUnit; 147 } 148 takeCurrentASTUnit()149 std::unique_ptr<ASTUnit> takeCurrentASTUnit() { 150 return std::move(CurrentASTUnit); 151 } 152 153 void setCurrentInput(const FrontendInputFile &CurrentInput, 154 std::unique_ptr<ASTUnit> AST = nullptr); 155 156 /// @} 157 /// @name Supported Modes 158 /// @{ 159 160 /// \brief Is this action invoked on a model file? 161 /// 162 /// Model files are incomplete translation units that relies on type 163 /// information from another translation unit. Check ParseModelFileAction for 164 /// details. isModelParsingAction()165 virtual bool isModelParsingAction() const { return false; } 166 167 /// \brief Does this action only use the preprocessor? 168 /// 169 /// If so no AST context will be created and this action will be invalid 170 /// with AST file inputs. 171 virtual bool usesPreprocessorOnly() const = 0; 172 173 /// \brief For AST-based actions, the kind of translation unit we're handling. getTranslationUnitKind()174 virtual TranslationUnitKind getTranslationUnitKind() { return TU_Complete; } 175 176 /// \brief Does this action support use with PCH? hasPCHSupport()177 virtual bool hasPCHSupport() const { return !usesPreprocessorOnly(); } 178 179 /// \brief Does this action support use with AST files? hasASTFileSupport()180 virtual bool hasASTFileSupport() const { return !usesPreprocessorOnly(); } 181 182 /// \brief Does this action support use with IR files? hasIRSupport()183 virtual bool hasIRSupport() const { return false; } 184 185 /// \brief Does this action support use with code completion? hasCodeCompletionSupport()186 virtual bool hasCodeCompletionSupport() const { return false; } 187 188 /// @} 189 /// @name Public Action Interface 190 /// @{ 191 192 /// \brief Prepare the action for processing the input file \p Input. 193 /// 194 /// This is run after the options and frontend have been initialized, 195 /// but prior to executing any per-file processing. 196 /// 197 /// \param CI - The compiler instance this action is being run from. The 198 /// action may store and use this object up until the matching EndSourceFile 199 /// action. 200 /// 201 /// \param Input - The input filename and kind. Some input kinds are handled 202 /// specially, for example AST inputs, since the AST file itself contains 203 /// several objects which would normally be owned by the 204 /// CompilerInstance. When processing AST input files, these objects should 205 /// generally not be initialized in the CompilerInstance -- they will 206 /// automatically be shared with the AST file in between 207 /// BeginSourceFile() and EndSourceFile(). 208 /// 209 /// \return True on success; on failure the compilation of this file should 210 /// be aborted and neither Execute() nor EndSourceFile() should be called. 211 bool BeginSourceFile(CompilerInstance &CI, const FrontendInputFile &Input); 212 213 /// \brief Set the source manager's main input file, and run the action. 214 bool Execute(); 215 216 /// \brief Perform any per-file post processing, deallocate per-file 217 /// objects, and run statistics and output file cleanup code. 218 void EndSourceFile(); 219 220 /// @} 221 }; 222 223 /// \brief Abstract base class to use for AST consumer-based frontend actions. 224 class ASTFrontendAction : public FrontendAction { 225 protected: 226 /// \brief Implement the ExecuteAction interface by running Sema on 227 /// the already-initialized AST consumer. 228 /// 229 /// This will also take care of instantiating a code completion consumer if 230 /// the user requested it and the action supports it. 231 void ExecuteAction() override; 232 233 public: ASTFrontendAction()234 ASTFrontendAction() {} usesPreprocessorOnly()235 bool usesPreprocessorOnly() const override { return false; } 236 }; 237 238 class PluginASTAction : public ASTFrontendAction { 239 virtual void anchor(); 240 public: 241 std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI, 242 StringRef InFile) override = 0; 243 244 /// \brief Parse the given plugin command line arguments. 245 /// 246 /// \param CI - The compiler instance, for use in reporting diagnostics. 247 /// \return True if the parsing succeeded; otherwise the plugin will be 248 /// destroyed and no action run. The plugin is responsible for using the 249 /// CompilerInstance's Diagnostic object to report errors. 250 virtual bool ParseArgs(const CompilerInstance &CI, 251 const std::vector<std::string> &arg) = 0; 252 253 enum ActionType { 254 Cmdline, ///< Action is determined by the cc1 command-line 255 ReplaceAction, ///< Replace the main action 256 AddBeforeMainAction, ///< Execute the action before the main action 257 AddAfterMainAction ///< Execute the action after the main action 258 }; 259 /// \brief Get the action type for this plugin 260 /// 261 /// \return The action type. If the type is Cmdline then by default the 262 /// plugin does nothing and what it does is determined by the cc1 263 /// command-line. getActionType()264 virtual ActionType getActionType() { return Cmdline; } 265 }; 266 267 /// \brief Abstract base class to use for preprocessor-based frontend actions. 268 class PreprocessorFrontendAction : public FrontendAction { 269 protected: 270 /// \brief Provide a default implementation which returns aborts; 271 /// this method should never be called by FrontendAction clients. 272 std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI, 273 StringRef InFile) override; 274 275 public: usesPreprocessorOnly()276 bool usesPreprocessorOnly() const override { return true; } 277 }; 278 279 /// \brief A frontend action which simply wraps some other runtime-specified 280 /// frontend action. 281 /// 282 /// Deriving from this class allows an action to inject custom logic around 283 /// some existing action's behavior. It implements every virtual method in 284 /// the FrontendAction interface by forwarding to the wrapped action. 285 class WrapperFrontendAction : public FrontendAction { 286 std::unique_ptr<FrontendAction> WrappedAction; 287 288 protected: 289 std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI, 290 StringRef InFile) override; 291 bool BeginInvocation(CompilerInstance &CI) override; 292 bool BeginSourceFileAction(CompilerInstance &CI, StringRef Filename) override; 293 void ExecuteAction() override; 294 void EndSourceFileAction() override; 295 296 public: 297 /// Construct a WrapperFrontendAction from an existing action, taking 298 /// ownership of it. 299 WrapperFrontendAction(std::unique_ptr<FrontendAction> WrappedAction); 300 301 bool usesPreprocessorOnly() const override; 302 TranslationUnitKind getTranslationUnitKind() override; 303 bool hasPCHSupport() const override; 304 bool hasASTFileSupport() const override; 305 bool hasIRSupport() const override; 306 bool hasCodeCompletionSupport() const override; 307 }; 308 309 } // end namespace clang 310 311 #endif 312