[Needs review] Fix ASTMatchers clang unit test: add ignoringParenTmp AST matcher

Checked C binds string literals to temporaries. Add a matcher that ignores parens and temporary bindings on expressions and use the matcher in the IgnoringParens ASTMatcher test.

Author: kakje

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -886,6 +886,24 @@ AST_MATCHER_P(Expr, ignoringParenCasts, internal::Matcher<Expr>, InnerMatcher) {
   return InnerMatcher.matches(*Node.IgnoreParenCasts(), Finder, Builder);
 }
 
+/// Matches expressions that match InnerMatcher after parentheses and
+/// Checked C temporary binding expressions are stripped off.
+///
+/// Given
+/// \code
+///   char *a = "";
+/// \endcode
+/// The matcher
+///    varDecl(hasInitializer(ignoringParenTmp(stringLiteral())))
+/// would match the declaration for a.
+/// while
+///    varDecl(hasInitializer(stringLiteral()))
+/// would match the declaration for a only if the Checked C extension
+/// is disabled.
+AST_MATCHER_P(Expr, ignoringParenTmp, internal::Matcher<Expr>, InnerMatcher) {
+  return InnerMatcher.matches(*Node.IgnoreParenTmp(), Finder, Builder);
+}
+
 /// Matches expressions that match InnerMatcher after implicit casts and
 /// parentheses are stripped off.
 ///

clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp

@@ -1501,7 +1501,7 @@ TEST_P(ASTMatchersTest, IgnoringParens) {
   EXPECT_TRUE(matches("const char* str = (\"my-string\");",
                       traverse(ast_type_traits::TK_AsIs,
                                implicitCastExpr(hasSourceExpression(
-                                   ignoringParens(stringLiteral()))))));
+                                   ignoringParenTmp(stringLiteral()))))));
 }
 
 TEST_P(ASTMatchersTest, QualType) {