Support in hasDeclaration for types with getDecl()
Re-introducing r175532. The has_getDecl metafunction didn't compile with Visual
Studio. This revision approaches has_getDecl from a different angle that isn't
a problem for Visual Studio.
Added dedicated tests for the metafunction.
Reviewers: klimek
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176019 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/ASTMatchers/ASTMatchersInternal.h b/include/clang/ASTMatchers/ASTMatchersInternal.h
index e18e325..cdbde76 100644
--- a/include/clang/ASTMatchers/ASTMatchersInternal.h
+++ b/include/clang/ASTMatchers/ASTMatchersInternal.h
@@ -353,6 +353,23 @@
return Matcher<T>(Implementation);
}
+/// \brief Metafunction to determine if type T has a member called getDecl.
+template <typename T> struct has_getDecl {
+ struct Default { int getDecl; };
+ struct Derived : T, Default { };
+
+ template<typename C, C> struct CheckT;
+
+ // If T::getDecl exists, an ambiguity arises and CheckT will
+ // not be instantiable. This makes f(...) the only available
+ // overload.
+ template<typename C>
+ static char (&f(CheckT<int Default::*, &C::getDecl>*))[1];
+ template<typename C> static char (&f(...))[2];
+
+ static bool const value = sizeof(f<Derived>(0)) == 2;
+};
+
/// \brief Matches declarations for QualType and CallExpr.
///
/// Type argument DeclMatcherT is required by PolymorphicMatcherWithParam1 but
@@ -376,11 +393,13 @@
/// \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) const {
+ 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,
@@ -393,6 +412,15 @@
return matchesDecl(Node->getAsCXXRecordDecl(), Finder, Builder);
}
+ /// \brief Gets the TemplateDecl from a TemplateSpecializationType
+ /// and returns whether the inner matches on it.
+ bool matchesSpecialized(const TemplateSpecializationType &Node,
+ ASTMatchFinder *Finder,
+ BoundNodesTreeBuilder *Builder) const {
+ return matchesDecl(Node.getTemplateName().getAsTemplateDecl(),
+ Finder, Buidler);
+ }
+
/// \brief Extracts the Decl of the callee of a CallExpr and returns whether
/// the inner matcher matches on it.
bool matchesSpecialized(const CallExpr &Node, ASTMatchFinder *Finder,
diff --git a/unittests/ASTMatchers/ASTMatchersTest.cpp b/unittests/ASTMatchers/ASTMatchersTest.cpp
index 6301747..a759df9 100644
--- a/unittests/ASTMatchers/ASTMatchersTest.cpp
+++ b/unittests/ASTMatchers/ASTMatchersTest.cpp
@@ -818,6 +818,12 @@
qualType(hasDeclaration(enumDecl(hasName("X")))))))));
}
+TEST(HasDeclaration, HasGetDeclTraitTest) {
+ EXPECT_TRUE(internal::has_getDecl<TypedefType>::value);
+ EXPECT_TRUE(internal::has_getDecl<RecordType>::value);
+ EXPECT_FALSE(internal::has_getDecl<TemplateSpecializationType>::value);
+}
+
TEST(HasDeclaration, HasDeclarationOfTypeWithDecl) {
EXPECT_TRUE(matches("typedef int X; X a;",
varDecl(hasName("a"),
