[clang] Add a matcher for template template parameters.

There are already matchers for type template parameters and non-type template parameters, but somehow no matcher exists for template template parameters and I need it to write unit tests. Differential Revision: https://reviews.llvm.org/D85536 Reviewed By: aaron.ballman
llvm · Aug 11, 2020 · f4dccf1 · f4dccf1
1 parent e2f3240
commit f4dccf1
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diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -562,6 +562,18 @@ extern const internal::VariadicDynCastAllOfMatcher<Decl,
 extern const internal::VariadicDynCastAllOfMatcher<Decl, TemplateTypeParmDecl>
     templateTypeParmDecl;
 
+/// Matches template template parameter declarations.
+///
+/// Given
+/// \code
+///   template <template <typename> class Z, int N> struct C {};
+/// \endcode
+/// templateTypeParmDecl()
+///   matches 'Z', but not 'N'.
+extern const internal::VariadicDynCastAllOfMatcher<Decl,
+                                                   TemplateTemplateParmDecl>
+    templateTemplateParmDecl;
+
 /// Matches public C++ declarations and C++ base specifers that specify public
 /// inheritance.
 ///

diff --git a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -740,6 +740,9 @@ const internal::VariadicDynCastAllOfMatcher<Decl, NonTypeTemplateParmDecl>
     nonTypeTemplateParmDecl;
 const internal::VariadicDynCastAllOfMatcher<Decl, TemplateTypeParmDecl>
     templateTypeParmDecl;
+const internal::VariadicDynCastAllOfMatcher<Decl, TemplateTemplateParmDecl>
+    templateTemplateParmDecl;
+
 const internal::VariadicAllOfMatcher<QualType> qualType;
 const internal::VariadicAllOfMatcher<Type> type;
 const internal::VariadicAllOfMatcher<TypeLoc> typeLoc;

diff --git a/clang/lib/ASTMatchers/Dynamic/Registry.cpp b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -514,6 +514,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(templateArgumentCountIs);
   REGISTER_MATCHER(templateName);
   REGISTER_MATCHER(templateSpecializationType);
+  REGISTER_MATCHER(templateTemplateParmDecl);
   REGISTER_MATCHER(templateTypeParmDecl);
   REGISTER_MATCHER(templateTypeParmType);
   REGISTER_MATCHER(throughUsingDecl);

diff --git a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -408,6 +408,15 @@ TEST_P(ASTMatchersTest, TemplateTypeParmDecl) {
   EXPECT_TRUE(notMatches("template <int N> void f();", templateTypeParmDecl()));
 }
 
+TEST_P(ASTMatchersTest, TemplateTemplateParmDecl) {
+  if (!GetParam().isCXX())
+    return;
+  EXPECT_TRUE(matches("template <template <typename> class Z> void f();",
+                      templateTemplateParmDecl(hasName("Z"))));
+  EXPECT_TRUE(notMatches("template <typename, int> void f();",
+                         templateTemplateParmDecl()));
+}
+
 TEST_P(ASTMatchersTest, UserDefinedLiteral) {
   if (!GetParam().isCXX11OrLater()) {
     return;