1 //===--- ASTMatchFinder.h - Structural query framework ----------*- 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 //===----------------------------------------------------------------------===//
10 // Provides a way to construct an ASTConsumer that runs given matchers
11 // over the AST and invokes a given callback on every match.
13 // The general idea is to construct a matcher expression that describes a
14 // subtree match on the AST. Next, a callback that is executed every time the
15 // expression matches is registered, and the matcher is run over the AST of
16 // some code. Matched subexpressions can be bound to string IDs and easily
17 // be accessed from the registered callback. The callback can than use the
18 // AST nodes that the subexpressions matched on to output information about
19 // the match or construct changes that can be applied to the code.
22 // class HandleMatch : public MatchFinder::MatchCallback {
24 // virtual void Run(const MatchFinder::MatchResult &Result) {
25 // const CXXRecordDecl *Class =
26 // Result.Nodes.GetDeclAs<CXXRecordDecl>("id");
31 // int main(int argc, char **argv) {
32 // ClangTool Tool(argc, argv);
33 // MatchFinder finder;
34 // finder.AddMatcher(Id("id", record(hasName("::a_namespace::AClass"))),
36 // return Tool.Run(newFrontendActionFactory(&finder));
39 //===----------------------------------------------------------------------===//
41 #ifndef LLVM_CLANG_ASTMATCHERS_ASTMATCHFINDER_H
42 #define LLVM_CLANG_ASTMATCHERS_ASTMATCHFINDER_H
44 #include "clang/ASTMatchers/ASTMatchers.h"
45 #include "llvm/ADT/StringMap.h"
46 #include "llvm/Support/Timer.h"
50 namespace ast_matchers {
52 /// \brief A class to allow finding matches over the Clang AST.
54 /// After creation, you can add multiple matchers to the MatchFinder via
55 /// calls to addMatcher(...).
57 /// Once all matchers are added, newASTConsumer() returns an ASTConsumer
58 /// that will trigger the callbacks specified via addMatcher(...) when a match
61 /// The order of matches is guaranteed to be equivalent to doing a pre-order
62 /// traversal on the AST, and applying the matchers in the order in which they
63 /// were added to the MatchFinder.
65 /// See ASTMatchers.h for more information about how to create matchers.
67 /// Not intended to be subclassed.
70 /// \brief Contains all information for a given match.
72 /// Every time a match is found, the MatchFinder will invoke the registered
73 /// MatchCallback with a MatchResult containing information about the match.
75 MatchResult(const BoundNodes &Nodes, clang::ASTContext *Context);
77 /// \brief Contains the nodes bound on the current match.
79 /// This allows user code to easily extract matched AST nodes.
80 const BoundNodes Nodes;
82 /// \brief Utilities for interpreting the matched AST structures.
84 clang::ASTContext * const Context;
85 clang::SourceManager * const SourceManager;
89 /// \brief Called when the Match registered for it was successfully found
93 virtual ~MatchCallback();
95 /// \brief Called on every match by the \c MatchFinder.
96 virtual void run(const MatchResult &Result) = 0;
98 /// \brief Called at the start of each translation unit.
100 /// Optionally override to do per translation unit tasks.
101 virtual void onStartOfTranslationUnit() {}
103 /// \brief Called at the end of each translation unit.
105 /// Optionally override to do per translation unit tasks.
106 virtual void onEndOfTranslationUnit() {}
108 /// \brief An id used to group the matchers.
110 /// This id is used, for example, for the profiling output.
111 /// It defaults to "<unknown>".
112 virtual StringRef getID() const;
115 /// \brief Called when parsing is finished. Intended for testing only.
116 class ParsingDoneTestCallback {
118 virtual ~ParsingDoneTestCallback();
119 virtual void run() = 0;
122 struct MatchFinderOptions {
124 Profiling(llvm::StringMap<llvm::TimeRecord> &Records)
125 : Records(Records) {}
127 /// \brief Per bucket timing information.
128 llvm::StringMap<llvm::TimeRecord> &Records;
131 /// \brief Enables per-check timers.
133 /// It prints a report after match.
134 llvm::Optional<Profiling> CheckProfiling;
137 MatchFinder(MatchFinderOptions Options = MatchFinderOptions());
140 /// \brief Adds a matcher to execute when running over the AST.
142 /// Calls 'Action' with the BoundNodes on every match.
143 /// Adding more than one 'NodeMatch' allows finding different matches in a
144 /// single pass over the AST.
146 /// Does not take ownership of 'Action'.
148 void addMatcher(const DeclarationMatcher &NodeMatch,
149 MatchCallback *Action);
150 void addMatcher(const TypeMatcher &NodeMatch,
151 MatchCallback *Action);
152 void addMatcher(const StatementMatcher &NodeMatch,
153 MatchCallback *Action);
154 void addMatcher(const NestedNameSpecifierMatcher &NodeMatch,
155 MatchCallback *Action);
156 void addMatcher(const NestedNameSpecifierLocMatcher &NodeMatch,
157 MatchCallback *Action);
158 void addMatcher(const TypeLocMatcher &NodeMatch,
159 MatchCallback *Action);
162 /// \brief Adds a matcher to execute when running over the AST.
164 /// This is similar to \c addMatcher(), but it uses the dynamic interface. It
165 /// is more flexible, but the lost type information enables a caller to pass
166 /// a matcher that cannot match anything.
168 /// \returns \c true if the matcher is a valid top-level matcher, \c false
170 bool addDynamicMatcher(const internal::DynTypedMatcher &NodeMatch,
171 MatchCallback *Action);
173 /// \brief Creates a clang ASTConsumer that finds all matches.
174 std::unique_ptr<clang::ASTConsumer> newASTConsumer();
176 /// \brief Calls the registered callbacks on all matches on the given \p Node.
178 /// Note that there can be multiple matches on a single node, for
179 /// example when using decl(forEachDescendant(stmt())).
182 template <typename T> void match(const T &Node, ASTContext &Context) {
183 match(clang::ast_type_traits::DynTypedNode::create(Node), Context);
185 void match(const clang::ast_type_traits::DynTypedNode &Node,
186 ASTContext &Context);
189 /// \brief Finds all matches in the given AST.
190 void matchAST(ASTContext &Context);
192 /// \brief Registers a callback to notify the end of parsing.
194 /// The provided closure is called after parsing is done, before the AST is
195 /// traversed. Useful for benchmarking.
196 /// Each call to FindAll(...) will call the closure once.
197 void registerTestCallbackAfterParsing(ParsingDoneTestCallback *ParsingDone);
199 /// \brief For each \c Matcher<> a \c MatchCallback that will be called
201 struct MatchersByType {
202 std::vector<std::pair<internal::DynTypedMatcher, MatchCallback *>>
204 std::vector<std::pair<TypeMatcher, MatchCallback *>> Type;
205 std::vector<std::pair<NestedNameSpecifierMatcher, MatchCallback *>>
207 std::vector<std::pair<NestedNameSpecifierLocMatcher, MatchCallback *>>
208 NestedNameSpecifierLoc;
209 std::vector<std::pair<TypeLocMatcher, MatchCallback *>> TypeLoc;
210 /// \brief All the callbacks in one container to simplify iteration.
211 std::vector<MatchCallback *> AllCallbacks;
215 MatchersByType Matchers;
217 MatchFinderOptions Options;
219 /// \brief Called when parsing is done.
220 ParsingDoneTestCallback *ParsingDone;
223 /// \brief Returns the results of matching \p Matcher on \p Node.
225 /// Collects the \c BoundNodes of all callback invocations when matching
226 /// \p Matcher on \p Node and returns the collected results.
228 /// Multiple results occur when using matchers like \c forEachDescendant,
229 /// which generate a result for each sub-match.
233 template <typename MatcherT, typename NodeT>
234 SmallVector<BoundNodes, 1>
235 match(MatcherT Matcher, const NodeT &Node, ASTContext &Context);
237 template <typename MatcherT>
238 SmallVector<BoundNodes, 1>
239 match(MatcherT Matcher, const ast_type_traits::DynTypedNode &Node,
240 ASTContext &Context);
243 /// \brief Returns the first result of type \c NodeT bound to \p BoundTo.
245 /// Returns \c NULL if there is no match, or if the matching node cannot be
246 /// casted to \c NodeT.
248 /// This is useful in combanation with \c match():
250 /// const Decl *D = selectFirst<Decl>("id", match(Matcher.bind("id"),
253 template <typename NodeT>
255 selectFirst(StringRef BoundTo, const SmallVectorImpl<BoundNodes> &Results) {
256 for (const BoundNodes &N : Results) {
257 if (const NodeT *Node = N.getNodeAs<NodeT>(BoundTo))
264 class CollectMatchesCallback : public MatchFinder::MatchCallback {
266 void run(const MatchFinder::MatchResult &Result) override {
267 Nodes.push_back(Result.Nodes);
269 SmallVector<BoundNodes, 1> Nodes;
273 template <typename MatcherT>
274 SmallVector<BoundNodes, 1>
275 match(MatcherT Matcher, const ast_type_traits::DynTypedNode &Node,
276 ASTContext &Context) {
277 internal::CollectMatchesCallback Callback;
279 Finder.addMatcher(Matcher, &Callback);
280 Finder.match(Node, Context);
281 return std::move(Callback.Nodes);
284 template <typename MatcherT, typename NodeT>
285 SmallVector<BoundNodes, 1>
286 match(MatcherT Matcher, const NodeT &Node, ASTContext &Context) {
287 return match(Matcher, ast_type_traits::DynTypedNode::create(Node), Context);
290 } // end namespace ast_matchers
291 } // end namespace clang