Add has definition AST matcher

[juliehockett]

Summary

Adds AST matcher for the definition of a CXXRecordDecl.

[aaron.ballman]

Aside from a minor commenting nit, LGTM! Do you need me to commit this on your behalf? (If so, I can take care of the commenting fix.)

include/clang/ASTMatchers/ASTMatchers.h

5856

Might want to mention that this is specific to classes and not other things, like functions.

[juliehockett]

That'd be great -- thank you! I did request commit rights, so hopefully I'll be able to do it myself next time.

[aaron.ballman]

Commit in r319360

docs/LibASTMatchersReference.html

 specified line and
 cxxRecordDecl(hasMethod(hasOverloadedOperatorName("*")))
 matches the declaration of A.
 
 Usable as: Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXOperatorCallExpr.html">CXXOperatorCallExpr</a>&gt;, Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1FunctionDecl.html">FunctionDecl</a>&gt;
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('hasDefinition0')"><a name="hasDefinition0Anchor">hasDefinition</a></td><td></td></tr>
+<tr><td colspan="4" class="doc" id="hasDefinition0"><pre>Matches a declaration that is defined.
+
+Example matches x (matcher = cxxRecordDecl(hasDefinition()))
+class x {};
+class y;
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isDerivedFrom1')"><a name="isDerivedFrom1Anchor">isDerivedFrom</a></td><td>std::string BaseName</td></tr>
 <tr><td colspan="4" class="doc" id="isDerivedFrom1"><pre>Overloaded method as shortcut for isDerivedFrom(hasName(...)).
 </pre></td></tr>
 
 
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXRecordDecl.html">CXXRecordDecl</a>&gt;</td><td class="name" onclick="toggle('isExplicitTemplateSpecialization2')"><a name="isExplicitTemplateSpecialization2Anchor">isExplicitTemplateSpecialization</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="isExplicitTemplateSpecialization2"><pre>Matches explicit template specializations of function, class, or
 static member variable template instantiations.

include/clang/ASTMatchers/ASTMatchers.h

 /// \endcode
 /// cxxNewExpr(hasArraySize(intgerLiteral(equals(10))))
 ///   matches the expression 'new MyClass[10]'.
 AST_MATCHER_P(CXXNewExpr, hasArraySize, internal::Matcher<Expr>, InnerMatcher) {
   return Node.isArray() &&
     InnerMatcher.matches(*Node.getArraySize(), Finder, Builder);
 }
 
+/// \brief Matches a declaration that is defined.
+///
+/// Example matches x (matcher = cxxRecordDecl(hasDefinition()))
+/// \code
+/// class x {};
+/// class y;
+/// \endcode
+AST_MATCHER(CXXRecordDecl, hasDefinition) {
+  return Node.hasDefinition();
+}
+
 } // namespace ast_matchers
 } // namespace clang
 
 #endif // LLVM_CLANG_ASTMATCHERS_ASTMATCHERS_H

lib/ASTMatchers/Dynamic/Registry.cpp

RegistryMaps::RegistryMaps() {
   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(hasDefinition);
   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

EXPECT_TRUE(matches("struct MyClass {}; MyClass *p1 = new MyClass[10];",
                       cxxNewExpr(isArray())));
 }
 
 TEST(HasArraySize, Basic) {
   EXPECT_TRUE(matches("struct MyClass {}; MyClass *p1 = new MyClass[10];",
                       cxxNewExpr(hasArraySize(integerLiteral(equals(10))))));
 }
 
+TEST(HasDefinition, MatchesStructDefinition) {
+  EXPECT_TRUE(matches("struct x {};",
+                      cxxRecordDecl(hasDefinition())));
+  EXPECT_TRUE(notMatches("struct x;",
+                      cxxRecordDecl(hasDefinition())));
+}
+
+TEST(HasDefinition, MatchesClassDefinition) {
+  EXPECT_TRUE(matches("class x {};",
+                      cxxRecordDecl(hasDefinition())));
+  EXPECT_TRUE(notMatches("class x;",
+                      cxxRecordDecl(hasDefinition())));
+}
+
+TEST(HasDefinition, MatchesUnionDefinition) {
+  EXPECT_TRUE(matches("union x {};",
+                      cxxRecordDecl(hasDefinition())));
+  EXPECT_TRUE(notMatches("union x;",
+                      cxxRecordDecl(hasDefinition())));
+}
+
 } // namespace ast_matchers
 } // namespace clang