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

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.

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.

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 4f67441eeb13405a32ea6b9ed7d0a1cf77c39326..826595a37229b958ba3d9b646c7356f5ae5f48cc 100644 (file)
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -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);

diff --git a/gcc/testsuite/c-c++-common/gomp/atomic-32.c b/gcc/testsuite/c-c++-common/gomp/atomic-32.c
new file mode 100644 (file)
index 0000000..e39a967
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/atomic-32.c
@@ -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)" } */
+}