1 //===-- FrontendAction.h - Generic Frontend Action Interface ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// \brief Defines the clang::FrontendAction interface and various convenience
12 /// abstract classes (clang::ASTFrontendAction, clang::PluginASTAction,
13 /// clang::PreprocessorFrontendAction, and clang::WrapperFrontendAction)
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_CLANG_FRONTEND_FRONTENDACTION_H
19 #define LLVM_CLANG_FRONTEND_FRONTENDACTION_H
21 #include "clang/Basic/LLVM.h"
22 #include "clang/Basic/LangOptions.h"
23 #include "clang/Frontend/FrontendOptions.h"
24 #include "llvm/ADT/OwningPtr.h"
25 #include "llvm/ADT/StringRef.h"
33 class CompilerInstance;
35 /// Abstract base class for actions which can be performed by the frontend.
36 class FrontendAction {
37 FrontendInputFile CurrentInput;
38 OwningPtr<ASTUnit> CurrentASTUnit;
39 CompilerInstance *Instance;
40 friend class ASTMergeAction;
41 friend class WrapperFrontendAction;
44 ASTConsumer* CreateWrappedASTConsumer(CompilerInstance &CI,
48 /// @name Implementation Action Interface
51 /// \brief Create the AST consumer object for this action, if supported.
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.
57 /// \param CI - The current compiler instance, provided as a convenience, see
58 /// getCompilerInstance().
60 /// \param InFile - The current input file, provided as a convenience, see
63 /// \return The new AST consumer, or null on failure.
64 virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
65 StringRef InFile) = 0;
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.
71 /// \return True on success; on failure BeginSourceFileAction(),
72 /// ExecuteAction() and EndSourceFileAction() will not be called.
73 virtual bool BeginInvocation(CompilerInstance &CI) { return true; }
75 /// \brief Callback at the start of processing a single input.
77 /// \return True on success; on failure ExecutionAction() and
78 /// EndSourceFileAction() will not be called.
79 virtual bool BeginSourceFileAction(CompilerInstance &CI,
84 /// \brief Callback to run the program action, using the initialized
85 /// compiler instance.
87 /// This is guaranteed to only be called between BeginSourceFileAction()
88 /// and EndSourceFileAction().
89 virtual void ExecuteAction() = 0;
91 /// \brief Callback at the end of processing a single input.
93 /// This is guaranteed to only be called following a successful call to
94 /// BeginSourceFileAction (and BeginSourceFile).
95 virtual void EndSourceFileAction() {}
101 virtual ~FrontendAction();
103 /// @name Compiler Instance Access
106 CompilerInstance &getCompilerInstance() const {
107 assert(Instance && "Compiler instance not registered!");
111 void setCompilerInstance(CompilerInstance *Value) { Instance = Value; }
114 /// @name Current File Information
117 bool isCurrentFileAST() const {
118 assert(!CurrentInput.isEmpty() && "No current file!");
119 return CurrentASTUnit != 0;
122 const FrontendInputFile &getCurrentInput() const {
126 const StringRef getCurrentFile() const {
127 assert(!CurrentInput.isEmpty() && "No current file!");
128 return CurrentInput.getFile();
131 InputKind getCurrentFileKind() const {
132 assert(!CurrentInput.isEmpty() && "No current file!");
133 return CurrentInput.getKind();
136 ASTUnit &getCurrentASTUnit() const {
137 assert(CurrentASTUnit && "No current AST unit!");
138 return *CurrentASTUnit;
141 ASTUnit *takeCurrentASTUnit() {
142 return CurrentASTUnit.take();
145 void setCurrentInput(const FrontendInputFile &CurrentInput, ASTUnit *AST = 0);
148 /// @name Supported Modes
151 /// \brief Does this action only use the preprocessor?
153 /// If so no AST context will be created and this action will be invalid
154 /// with AST file inputs.
155 virtual bool usesPreprocessorOnly() const = 0;
157 /// \brief For AST-based actions, the kind of translation unit we're handling.
158 virtual TranslationUnitKind getTranslationUnitKind() { return TU_Complete; }
160 /// \brief Does this action support use with PCH?
161 virtual bool hasPCHSupport() const { return !usesPreprocessorOnly(); }
163 /// \brief Does this action support use with AST files?
164 virtual bool hasASTFileSupport() const { return !usesPreprocessorOnly(); }
166 /// \brief Does this action support use with IR files?
167 virtual bool hasIRSupport() const { return false; }
169 /// \brief Does this action support use with code completion?
170 virtual bool hasCodeCompletionSupport() const { return false; }
173 /// @name Public Action Interface
176 /// \brief Prepare the action for processing the input file \p Input.
178 /// This is run after the options and frontend have been initialized,
179 /// but prior to executing any per-file processing.
181 /// \param CI - The compiler instance this action is being run from. The
182 /// action may store and use this object up until the matching EndSourceFile
185 /// \param Input - The input filename and kind. Some input kinds are handled
186 /// specially, for example AST inputs, since the AST file itself contains
187 /// several objects which would normally be owned by the
188 /// CompilerInstance. When processing AST input files, these objects should
189 /// generally not be initialized in the CompilerInstance -- they will
190 /// automatically be shared with the AST file in between
191 /// BeginSourceFile() and EndSourceFile().
193 /// \return True on success; on failure the compilation of this file should
194 /// be aborted and neither Execute() nor EndSourceFile() should be called.
195 bool BeginSourceFile(CompilerInstance &CI, const FrontendInputFile &Input);
197 /// \brief Set the source manager's main input file, and run the action.
200 /// \brief Perform any per-file post processing, deallocate per-file
201 /// objects, and run statistics and output file cleanup code.
202 void EndSourceFile();
207 /// \brief Abstract base class to use for AST consumer-based frontend actions.
208 class ASTFrontendAction : public FrontendAction {
210 /// \brief Implement the ExecuteAction interface by running Sema on
211 /// the already-initialized AST consumer.
213 /// This will also take care of instantiating a code completion consumer if
214 /// the user requested it and the action supports it.
215 virtual void ExecuteAction();
218 virtual bool usesPreprocessorOnly() const { return false; }
221 class PluginASTAction : public ASTFrontendAction {
222 virtual void anchor();
224 virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
225 StringRef InFile) = 0;
228 /// \brief Parse the given plugin command line arguments.
230 /// \param CI - The compiler instance, for use in reporting diagnostics.
231 /// \return True if the parsing succeeded; otherwise the plugin will be
232 /// destroyed and no action run. The plugin is responsible for using the
233 /// CompilerInstance's Diagnostic object to report errors.
234 virtual bool ParseArgs(const CompilerInstance &CI,
235 const std::vector<std::string> &arg) = 0;
238 /// \brief Abstract base class to use for preprocessor-based frontend actions.
239 class PreprocessorFrontendAction : public FrontendAction {
241 /// \brief Provide a default implementation which returns aborts;
242 /// this method should never be called by FrontendAction clients.
243 virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
247 virtual bool usesPreprocessorOnly() const { return true; }
250 /// \brief A frontend action which simply wraps some other runtime-specified
253 /// Deriving from this class allows an action to inject custom logic around
254 /// some existing action's behavior. It implements every virtual method in
255 /// the FrontendAction interface by forwarding to the wrapped action.
256 class WrapperFrontendAction : public FrontendAction {
257 OwningPtr<FrontendAction> WrappedAction;
260 virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
262 virtual bool BeginInvocation(CompilerInstance &CI);
263 virtual bool BeginSourceFileAction(CompilerInstance &CI,
265 virtual void ExecuteAction();
266 virtual void EndSourceFileAction();
269 /// Construct a WrapperFrontendAction from an existing action, taking
271 WrapperFrontendAction(FrontendAction *WrappedAction);
273 virtual bool usesPreprocessorOnly() const;
274 virtual TranslationUnitKind getTranslationUnitKind();
275 virtual bool hasPCHSupport() const;
276 virtual bool hasASTFileSupport() const;
277 virtual bool hasIRSupport() const;
278 virtual bool hasCodeCompletionSupport() const;
281 } // end namespace clang