Adds hasUnqualifiedDesugaredType to allow matching through type sugar.

Differential Revision: https://reviews.llvm.org/D27207

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@288366 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/ASTMatchers/ASTMatchers.h

@@ -2738,6 +2738,22 @@ AST_MATCHER_P_OVERLOAD(QualType, pointsTo, internal::Matcher<Decl>,
       .matches(Node, Finder, Builder);
 }
 
+/// \brief Matches if the matched type matches the unqualified desugared
+/// type of the matched node.
+///
+/// For example, in:
+/// \code
+///   class A {};
+///   using B = A;
+/// \endcode
+/// The matcher type(hasUniqualifeidDesugaredType(recordType())) matches
+/// both B and A.
+AST_MATCHER_P(Type, hasUnqualifiedDesugaredType, internal::Matcher<Type>,
+              InnerMatcher) {
+  return InnerMatcher.matches(*Node.getUnqualifiedDesugaredType(), Finder,
+                              Builder);
+}
+
 /// \brief Matches if the matched type is a reference type and the referenced
 /// type matches the specified matcher.
 ///

lib/ASTMatchers/Dynamic/Registry.cpp

@@ -270,6 +270,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasUnaryOperand);
   REGISTER_MATCHER(hasUnarySelector);
   REGISTER_MATCHER(hasUnderlyingDecl);
+  REGISTER_MATCHER(hasUnqualifiedDesugaredType);
   REGISTER_MATCHER(hasValueType);
   REGISTER_MATCHER(ifStmt);
   REGISTER_MATCHER(ignoringImplicit);

unittests/ASTMatchers/ASTMatchersTraversalTest.cpp

@@ -247,6 +247,15 @@ TEST(HasDeclaration, HasDeclarationOfCXXNewExpr) {
               cxxNewExpr(hasDeclaration(functionDecl(parameterCountIs(1))))));
 }
 
+TEST(HasUnqualifiedDesugaredType, DesugarsUsing) {
+  EXPECT_TRUE(
+      matches("struct A {}; using B = A; B b;",
+              varDecl(hasType(hasUnqualifiedDesugaredType(recordType())))));
+  EXPECT_TRUE(
+      matches("struct A {}; using B = A; using C = B; C b;",
+              varDecl(hasType(hasUnqualifiedDesugaredType(recordType())))));
+}
+
 TEST(HasUnderlyingDecl, Matches) {
   EXPECT_TRUE(matches("namespace N { template <class T> void f(T t); }"
                       "template <class T> void g() { using N::f; f(T()); }",