[ASTMatcher] Add clang-query disclaimer to two more matchers that take enum

As we have figured out in
https://reviews.llvm.org/D57112
and
https://bugs.llvm.org/show_bug.cgi?id=41176

this kind-of works, but needs special care.

llvm-svn: 356677

clang/docs/LibASTMatchersReference.html

@@ -2640,6 +2640,9 @@ Example matches y(x) but not y(42) or NS::y(x).
 Example: matches the implicit cast around 0
 (matcher = castExpr(hasCastKind(CK_NullToPointer)))
   int *p = 0;
+
+If the matcher is use from clang-query, CastKind parameter
+should be passed as a quoted string. e.g., ofKind("CK_NullToPointer").
 </pre></td></tr>
 
 
@@ -4086,6 +4089,9 @@ Given
   int s = sizeof(x) + alignof(x)
 unaryExprOrTypeTraitExpr(ofKind(UETT_SizeOf))
   matches sizeof(x)
+
+If the matcher is use from clang-query, UnaryExprOrTypeTrait parameter
+should be passed as a quoted string. e.g., ofKind("UETT_SizeOf").
 </pre></td></tr>
 
 

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -2492,6 +2492,9 @@ AST_MATCHER_P(UnaryExprOrTypeTraitExpr, hasArgumentOfType,
 /// \endcode
 /// unaryExprOrTypeTraitExpr(ofKind(UETT_SizeOf))
 ///   matches \c sizeof(x)
+///
+/// If the matcher is use from clang-query, UnaryExprOrTypeTrait parameter
+/// should be passed as a quoted string. e.g., ofKind("UETT_SizeOf").
 AST_MATCHER_P(UnaryExprOrTypeTraitExpr, ofKind, UnaryExprOrTypeTrait, Kind) {
   return Node.getKind() == Kind;
 }
@@ -4483,6 +4486,9 @@ AST_POLYMORPHIC_MATCHER_P(hasSourceExpression,
 /// \code
 ///   int *p = 0;
 /// \endcode
+///
+/// If the matcher is use from clang-query, CastKind parameter
+/// should be passed as a quoted string. e.g., ofKind("CK_NullToPointer").
 AST_MATCHER_P(CastExpr, hasCastKind, CastKind, Kind) {
   return Node.getCastKind() == Kind;
 }