Support in hasDeclaration for types with getDecl()

    
Using a new metafunction for detecting the presence of the member
'getDecl' in a type T, added support to hasDeclaration for any such type
T. This allows hasDecl() to be replaced and enables several other
subclasses of clang::Type to use hasDeclaration.

Updated unittests and LibASTMatchersReference.html.

Reviewers: klimek


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175532 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 26 insertions, 8 deletions

diff --git a/include/clang/ASTMatchers/ASTMatchers.h b/include/clang/ASTMatchers/ASTMatchers.h
index fe2c14f58b..de9919aaf0 100644
--- a/include/clang/ASTMatchers/ASTMatchers.h
+++ b/include/clang/ASTMatchers/ASTMatchers.h
@@ -1561,8 +1561,12 @@ unless(const M &InnerMatcher) {
 /// \brief Matches a type if the declaration of the type matches the given
 /// matcher.
 ///
+/// In addition to being usable as Matcher<TypedefType>, also usable as
+/// Matcher<T> for any T supporting the getDecl() member function. e.g. various
+/// subtypes of clang::Type.
+///
 /// Usable as: Matcher<QualType>, Matcher<CallExpr>, Matcher<CXXConstructExpr>,
-///   Matcher<MemberExpr>
+///   Matcher<MemberExpr>, Matcher<TypedefType>
 inline internal::PolymorphicMatcherWithParam1< internal::HasDeclarationMatcher,
                                      internal::Matcher<Decl> >
     hasDeclaration(const internal::Matcher<Decl> &InnerMatcher) {
@@ -2846,13 +2850,6 @@ AST_TYPELOC_TRAVERSE_MATCHER(pointee, getPointee);
 ///   matches "typedef int X"
 AST_TYPE_MATCHER(TypedefType, typedefType);
 
-/// \brief Matches \c TypedefTypes referring to a specific
-/// \c TypedefNameDecl.
-AST_MATCHER_P(TypedefType, hasDecl,
-              internal::Matcher<TypedefNameDecl>, InnerMatcher) {
-  return InnerMatcher.matches(*Node.getDecl(), Finder, Builder);
-}
-
 /// \brief Matches nested name specifiers.
 ///
 /// Given
diff --git a/include/clang/ASTMatchers/ASTMatchersInternal.h b/include/clang/ASTMatchers/ASTMatchersInternal.h
index b41a74ce83..cc4edacf42 100644
--- a/include/clang/ASTMatchers/ASTMatchersInternal.h
+++ b/include/clang/ASTMatchers/ASTMatchersInternal.h
@@ -353,6 +353,18 @@ inline Matcher<T> makeMatcher(MatcherInterface<T> *Implementation) {
   return Matcher<T>(Implementation);
 }
 
+/// \brief Metafunction to determine if type T has a member called getDecl.
+template <typename T> struct has_getDecl {
+  typedef char yes[1];
+  typedef char no[2];
+
+  template <typename TestType>
+  static yes &test(char[sizeof(&TestType::getDecl)]);
+  template <typename> static no &test(...);
+
+  static bool const value = sizeof(test<T>(0)) == sizeof(yes);
+};
+
 /// \brief Matches declarations for QualType and CallExpr.
 ///
 /// Type argument DeclMatcherT is required by PolymorphicMatcherWithParam1 but
@@ -373,6 +385,15 @@ public:
   }
 
 private:
+  /// \brief If getDecl exists as a member of U, returns whether the inner
+  /// matcher matches Node.getDecl().
+  template <typename U>
+  bool matchesSpecialized(
+      const U &Node, ASTMatchFinder *Finder, BoundNodesTreeBuilder *Builder,
+      typename llvm::enable_if<has_getDecl<U>, int>::type = 0) const {
+    return matchesDecl(Node.getDecl(), Finder, Builder);
+  }
+
   /// \brief Extracts the CXXRecordDecl or EnumDecl of a QualType and returns
   /// whether the inner matcher matches on it.
   bool matchesSpecialized(const QualType &Node, ASTMatchFinder *Finder,