[gcc r12-1990] openmp: Reject #pragma omp atomic update, [PR101297]

[gcc r12-1990] openmp: Reject #pragma omp atomic update, [PR101297]

[Jakub Jelinek]

https://gcc.gnu.org/g:2ca89394280da4afad6074ec3cb7136b6142af7b

commit r12-1990-g2ca89394280da4afad6074ec3cb7136b6142af7b
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Jul 2 21:57:24 2021 +0200

    openmp: Reject #pragma omp atomic update, [PR101297]
    
    I've noticed that we allow a trailing comma on OpenMP atomic construct
    if there is at least one clause.  Commas should be only allowed to
    separate the clauses (or in OpenMP 5.1 to separate directive name
    from the clauses).
    
    2021-07-02  Jakub Jelinek  <jakub@redhat.com>
    
            PR c/101297
            * c-parser.c (c_parser_omp_atomic): Consume comma only if it
            appears before a CPP_NAME.
    
            * parser.c (cp_parser_omp_atomic): Consume comma only if it
            appears before a CPP_NAME.
    
            * c-c++-common/gomp/atomic-24.c: New test.

Diff:
---
 gcc/c/c-parser.c                            |  4 +++-
 gcc/cp/parser.c                             |  4 +++-
 gcc/testsuite/c-c++-common/gomp/atomic-24.c | 12 ++++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 3922b569c3a..9a56e0c04c6 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -17533,7 +17533,9 @@ c_parser_omp_atomic (location_t loc, c_parser *parser, bool openacc)
 
   while (c_parser_next_token_is_not (parser, CPP_PRAGMA_EOL))
     {
-      if (!first && c_parser_next_token_is (parser, CPP_COMMA))
+      if (!first
+	  && c_parser_next_token_is (parser, CPP_COMMA)
+	  && c_parser_peek_2nd_token (parser)->type == CPP_NAME)
 	c_parser_consume_token (parser);
 
       first = false;
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 02daa7a6f6a..3550cd06dc1 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -39171,7 +39171,9 @@ cp_parser_omp_atomic (cp_parser *parser, cp_token *pragma_tok, bool openacc)
 
   while (cp_lexer_next_token_is_not (parser->lexer, CPP_PRAGMA_EOL))
     {
-      if (!first && cp_lexer_next_token_is (parser->lexer, CPP_COMMA))
+      if (!first
+	  && cp_lexer_next_token_is (parser->lexer, CPP_COMMA)
+	  && cp_lexer_nth_token_is (parser->lexer, 2, CPP_NAME))
 	cp_lexer_consume_token (parser->lexer);
 
       first = false;
diff --git a/gcc/testsuite/c-c++-common/gomp/atomic-24.c b/gcc/testsuite/c-c++-common/gomp/atomic-24.c
new file mode 100644
index 00000000000..f70c8051023
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/atomic-24.c
@@ -0,0 +1,12 @@
+/* PR c/101297 */
+
+int i;
+
+void
+foo (void)
+{
+  #pragma omp atomic update,	/* { dg-error "expected end of line before ',' token" } */
+  i++;
+  #pragma omp atomic update,,	/* { dg-error "expected end of line before ',' token" } */
+  i++;
+}