[committed] openmp: Reject invalid forms of C++ #pragma omp atomic compare [PR106448]

[committed] openmp: Reject invalid forms of C++ #pragma omp atomic compare [PR106448]

[Jakub Jelinek]

Hi!

The allowed syntaxes of atomic compare don't allow ()s around the condition
of ?:, but we were accepting it in one case for C++.

Fixed thusly.

Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk.

2022-07-29  Jakub Jelinek  <jakub@redhat.com>

	PR c++/106448
	* parser.cc (cp_parser_omp_atomic): For simple cast followed by
	CPP_QUERY token, don't try cp_parser_binary_operation if compare
	is true.

	* c-c++-common/gomp/atomic-32.c: New test.

--- gcc/cp/parser.cc.jj	2022-07-26 10:32:23.557273390 +0200
+++ gcc/cp/parser.cc	2022-07-28 15:12:44.288195066 +0200
@@ -41535,7 +41535,9 @@ restart:
 	      goto saw_error;
 	    }
 	  token = cp_lexer_peek_token (parser->lexer);
-	  if (token->type != CPP_SEMICOLON && !cp_tree_equal (lhs, rhs1))
+	  if (token->type != CPP_SEMICOLON
+	      && (!compare || token->type != CPP_QUERY)
+	      && !cp_tree_equal (lhs, rhs1))
 	    {
 	      cp_parser_abort_tentative_parse (parser);
 	      cp_parser_parse_tentatively (parser);
--- gcc/testsuite/c-c++-common/gomp/atomic-32.c.jj	2022-07-28 15:23:54.567237524 +0200
+++ gcc/testsuite/c-c++-common/gomp/atomic-32.c	2022-07-28 15:25:25.127027325 +0200
@@ -0,0 +1,14 @@
+/* PR c++/106448 */
+
+int x, expr;
+  
+void
+foo (void)
+{
+  #pragma omp atomic compare
+  x = (expr > x) ? expr : x;	/* { dg-error "invalid (form|operator)" } */
+  #pragma omp atomic compare
+  x = (x < expr) ? expr : x;	/* { dg-error "invalid (form|operator)" } */
+  #pragma omp atomic compare
+  x = (x == expr) ? expr : x;	/* { dg-error "invalid (form|operator)" } */
+}

	Jakub