[gcc r9-9394] openmp: Fix C ICE on OpenMP atomics

[gcc r9-9394] openmp: Fix C ICE on OpenMP atomics

[Jakub Jelinek]

https://gcc.gnu.org/g:28a164db98d7cb8fa82ac3699471830284502021

commit r9-9394-g28a164db98d7cb8fa82ac3699471830284502021
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Nov 24 09:04:28 2020 +0100

    openmp: Fix C ICE on OpenMP atomics
    
    c_parser_binary_expression was using build2 to create a temporary holder
    for binary expression that c_parser_atomic and c_finish_omp_atomic can then
    handle.  The latter performs then all the needed checking.
    
    Unfortunately, build2 performs some checking too, e.g. PLUS_EXPR vs.
    POINTER_PLUS_EXPR or matching types of the arguments, nothing we can guarantee
    at the parsing time.  So we need something like C++ build_min_nt*.  This
    patch implements that inline.
    
    2020-11-24  Jakub Jelinek  <jakub@redhat.com>
    
            PR c/97958
            * c-parser.c (c_parser_binary_expression): For omp atomic binary
            expressions, use make_node instead of build2 to avoid checking build2
            performs.
    
            * c-c++-common/gomp/pr97958.c: New test.
    
    (cherry picked from commit 1cd47144fd250f37206c8e2a0cc7d51c25ad368c)

Diff:
---
 gcc/c/c-parser.c                          | 10 +++++++---
 gcc/testsuite/c-c++-common/gomp/pr97958.c | 17 +++++++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 53e90c78a47..bfeacaa0a45 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -7034,9 +7034,13 @@ c_parser_binary_expression (c_parser *parser, struct c_expr *after,
 	&& stack[1].expr.value != error_mark_node			      \
 	&& (c_tree_equal (stack[0].expr.value, omp_atomic_lhs)		      \
 	    || c_tree_equal (stack[1].expr.value, omp_atomic_lhs)))	      \
-      stack[0].expr.value						      \
-	= build2 (stack[1].op, TREE_TYPE (stack[0].expr.value),		      \
-		  stack[0].expr.value, stack[1].expr.value);		      \
+      {									      \
+	tree t = make_node (stack[1].op);				      \
+	TREE_TYPE (t) = TREE_TYPE (stack[0].expr.value);		      \
+	TREE_OPERAND (t, 0) = stack[0].expr.value;			      \
+	TREE_OPERAND (t, 1) = stack[1].expr.value;			      \
+	stack[0].expr.value = t;					      \
+      }									      \
     else								      \
       stack[sp - 1].expr = parser_build_binary_op (stack[sp].loc,	      \
 						   stack[sp].op,	      \
diff --git a/gcc/testsuite/c-c++-common/gomp/pr97958.c b/gcc/testsuite/c-c++-common/gomp/pr97958.c
new file mode 100644
index 00000000000..5a6de02f373
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/pr97958.c
@@ -0,0 +1,17 @@
+/* PR c/97958 */
+
+int *p;
+
+void
+foo (void)
+{
+  #pragma omp atomic
+  p = p + 1;
+}
+
+void
+bar (void)
+{
+  #pragma omp atomic	/* { dg-error "invalid expression type for '#pragma omp atomic'" } */
+  bar = bar + 1;
+}