Add default argument AST matcher

[juliehockett]

Summary

Adds AST matcher for declarations with default arguments.

[aaron.ballman]

You should also update lib\ASTMatchers\Dynamic\Registry.cpp to have the new matcher (be sure to keep the new matcher alphabetized as well).

[juliehockett]

Updated Registry.cpp to include new matcher.

[aaron.ballman]

Aside from a minor nit with the comments leading to the public docs, LGTM!

include/clang/ASTMatchers/ASTMatchers.h

5825–5826

Remove the spurious semicolons (and regen the HTML docs).

[juliehockett]

Removed spurious semicolons

[aaron.ballman]

I did find a few more spurious semicolons with the testing code as well.

If you need me to commit this on your behalf, I'm happy to do so, though it won't happen until tomorrow or Wed. Or, if you have commit privs, feel free to commit with the fixed test case.

unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

1995–1997

Spurious semicolons in here as well (sorry, I missed that before).

[juliehockett]

It'd be great if you could commit it -- I don't have commit privileges. Much appreciated!

[aaron.ballman]

I've commit in r318794, thank you!

docs/LibASTMatchersReference.html

Example matches A, va, fa
   - (void)ma {}
   @end
 
 Usable as: Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1TagDecl.html">TagDecl</a>&gt;, Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1VarDecl.html">VarDecl</a>&gt;, Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1FunctionDecl.html">FunctionDecl</a>&gt;,
   Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1ObjCMethodDecl.html">ObjCMethodDecl</a>&gt;
 </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.
 
 Given
   class Y { public: void x(); };
   void z() { Y* y; y-&gt;x(); }
 cxxMemberCallExpr(on(hasType(asString("class Y *"))))
   matches y-&gt;x()

include/clang/ASTMatchers/ASTMatchers.h

 /// namespace {
 /// void f() {}
 /// }
 /// \endcode
 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
 
 #endif // LLVM_CLANG_ASTMATCHERS_ASTMATCHERS_H

lib/ASTMatchers/Dynamic/Registry.cpp

RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasCaseConstant);
   REGISTER_MATCHER(hasCastKind);
   REGISTER_MATCHER(hasCondition);
   REGISTER_MATCHER(hasConditionVariableStatement);
   REGISTER_MATCHER(hasDecayedType);
   REGISTER_MATCHER(hasDeclaration);
   REGISTER_MATCHER(hasDeclContext);
   REGISTER_MATCHER(hasDeducedType);
+  REGISTER_MATCHER(hasDefaultArgument);
   REGISTER_MATCHER(hasDescendant);
   REGISTER_MATCHER(hasDestinationType);
   REGISTER_MATCHER(hasDynamicExceptionSpec);
   REGISTER_MATCHER(hasEitherOperand);
   REGISTER_MATCHER(hasElementType);
   REGISTER_MATCHER(hasElse);
   REGISTER_MATCHER(hasExternalFormalLinkage);
   REGISTER_MATCHER(hasFalseExpression);

unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

TEST(HasExternalFormalLinkage, Basic) {
 
   // Despite having internal semantic linkage, the anonymous namespace member
   // has external linkage because the member has a unique name in all
   // translation units.
   EXPECT_TRUE(matches("namespace { int a = 0; }",
                       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