Correct documentation for numSelectorArgs matcher

[kastiglione]

Summary

Currently, the documentation for numSelectorArgs includes an incorrect example. It shows a case where an argument of 1 will match a property getter, but a getter will be matched only when N == 0.

This diff corrects the documentation and adds a test for numSelectorArgs(0).

[klimek]

include/clang/ASTMatchers/ASTMatchers.h

2140–2153

It seems like numSelectorArgs is missing unit tests - it might be good to add one, so we're sure the documented version now works and is tested :)

[kastiglione]

include/clang/ASTMatchers/ASTMatchers.h

2140–2153

Thanks @klimek. Where are tests for ASTMatchers? I'm new to the codebase, I grepped for "matcher" in test/ but there are no relevant files.

[kastiglione]

Add test case for numSelectorArgs(0)

[klimek]

+Dean, as I really don't know Obj-C (sorry for the delay in reply, was on vacation)

[kastiglione]

Thanks @klimek! There's certainly no rush on a diff like this :P

[klimek]

LG, as this is a documentation change that looks about right, and comes with tests, and the original author doesn't jump in.

[klimek]

Committed as r246998.

[kastiglione]

Thank you @klimek.

include/clang/ASTMatchers/ASTMatchers.h

 ///   webView.frame = bodyFrame;
 ///   //     ^---- matches here
 /// \endcode
 
 AST_MATCHER(ObjCMessageExpr, hasKeywordSelector) {
   return Node.getSelector().isKeywordSelector();
 }
 
 /// \brief Matches when the selector has the specified number of arguments
 ///
-///  matcher = objCMessageExpr(numSelectorArgs(1));
+///  matcher = objCMessageExpr(numSelectorArgs(0));
 ///  matches self.bodyView in the code below
 ///
 ///  matcher = objCMessageExpr(numSelectorArgs(2));
 ///  matches the invocation of "loadHTMLString:baseURL:" but not that
 ///  of self.bodyView
 /// \code
 ///     [self.bodyView loadHTMLString:html baseURL:NULL];
 /// \endcode
 AST_MATCHER_P(ObjCMessageExpr, numSelectorArgs, unsigned, N) {
   return Node.getSelector().getNumArgs() == N;
 }
    
 /// \brief Matches if the call expression's callee expression matches.
 ///
 /// Given
 /// \code
 ///   class Y { void x() { this->x(); x(); Y y; y.x(); } };
 ///   void f() { f(); }
 /// \endcode

unittests/ASTMatchers/ASTMatchersTest.cpp

TEST(ObjCMessageExprMatcher, SimpleExprs) {
   EXPECT_TRUE(notMatchesObjC(
       Objc1String,
       objcMessageExpr(hasSelector("contents"), hasNullSelector())));
   EXPECT_TRUE(matchesObjC(
       Objc1String,
       objcMessageExpr(hasSelector("contents"), hasUnarySelector())));
   EXPECT_TRUE(matchesObjC(
       Objc1String,
+      objcMessageExpr(hasSelector("contents"), numSelectorArgs(0))));
+  EXPECT_TRUE(matchesObjC(
+      Objc1String,
       objcMessageExpr(matchesSelector("uppercase*"),
                       argumentCountIs(0)
                       )));
   
 }
 
 } // end namespace ast_matchers
 } // end namespace clang