In function handle_vector_size_attribute local variable nunits is
supposed to be initialized by function type_valid_for_vector_size.
However, in case ARGS is null the function may return with a non-null
value and leave nunits uninitialized. This results in warning/error:
gcc/poly-int.h: In function 'tree_node*
handle_vector_size_attribute(tree_node**, tree, tree, int, bool*)':
gcc/poly-int.h:330:3: error: 'nunits' may be used uninitialized in this
function [-Werror=maybe-uninitialized]
330 | ((void) (&(RES).coeffs[0] == (C *) 0), \
| ^
gcc/c-family/c-attribs.c:3695:26: note: 'nunits' was declared here
3695 | unsigned HOST_WIDE_INT nunits;
|
This is fixed by also checking whether ARGS is null or not.
Bootstrapped and regtested on S/390. Ok for master?
gcc/c-family/ChangeLog:
2020-04-28 Stefan Schulze Frielinghaus <[email protected]>
* c-attribs.c (handle_vector_size_attribute): Fix use of
unintialized variable nunits.
---
gcc/c-family/c-attribs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index ac936d5bbbb..a8992e76755 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -3694,7 +3694,7 @@ handle_vector_size_attribute (tree *node, tree name, tree
args,
the number of vector units. */
unsigned HOST_WIDE_INT nunits;
type = type_valid_for_vector_size (type, name, args, &nunits);
- if (!type)
+ if (!type || !args)
return NULL_TREE;
tree new_type = build_vector_type (type, nunits);
--
2.25.3
