Add an AST matcher for hasDefaultArgument() to match on parameter declarations that have a default value.

Patch by Julie Hockett.

llvm-svn: 318794

clang/docs/LibASTMatchersReference.html

@@ -3183,6 +3183,15 @@ Usable as: Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1TagDe
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1ParmVarDecl.html">ParmVarDecl</a>&gt;</td><td class="name" onclick="toggle('hasDefaultArgument0')"><a name="hasDefaultArgument0Anchor">hasDefaultArgument</a></td><td></td></tr>
+<tr><td colspan="4" class="doc" id="hasDefaultArgument0"><pre>Matches a declaration that has default arguments.
+
+Example matches y (matcher = parmVarDecl(hasDefaultArgument()))
+void x(int val) {}
+void y(int val = 0) {}
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1QualType.html">QualType</a>&gt;</td><td class="name" onclick="toggle('asString0')"><a name="asString0Anchor">asString</a></td><td>std::string Name</td></tr>
 <tr><td colspan="4" class="doc" id="asString0"><pre>Matches if the matched type is represented by the given string.
 

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -5817,6 +5817,17 @@ AST_MATCHER(NamedDecl, hasExternalFormalLinkage) {
   return Node.hasExternalFormalLinkage();
 }
 
+/// \brief Matches a declaration that has default arguments.
+///
+/// Example matches y (matcher = parmVarDecl(hasDefaultArgument()))
+/// \code
+/// void x(int val) {}
+/// void y(int val = 0) {}
+/// \endcode
+AST_MATCHER(ParmVarDecl, hasDefaultArgument) { 
+  return Node.hasDefaultArg(); 
+}
+
 } // namespace ast_matchers
 } // namespace clang
 

clang/lib/ASTMatchers/Dynamic/Registry.cpp

@@ -248,6 +248,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasDeclaration);
   REGISTER_MATCHER(hasDeclContext);
   REGISTER_MATCHER(hasDeducedType);
+  REGISTER_MATCHER(hasDefaultArgument);
   REGISTER_MATCHER(hasDescendant);
   REGISTER_MATCHER(hasDestinationType);
   REGISTER_MATCHER(hasDynamicExceptionSpec);

clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

@@ -1991,5 +1991,12 @@ TEST(HasExternalFormalLinkage, Basic) {
                       namedDecl(hasExternalFormalLinkage())));
 }
 
+TEST(HasDefaultArgument, Basic) {
+  EXPECT_TRUE(matches("void x(int val = 0) {}", 
+                      parmVarDecl(hasDefaultArgument())));
+  EXPECT_TRUE(notMatches("void x(int val) {}",
+                      parmVarDecl(hasDefaultArgument())));
+}
+
 } // namespace ast_matchers
 } // namespace clang