> Am 06.12.2025 um 11:07 schrieb Jakub Jelinek <[email protected]>:
>
> Hi!
>
> The following testcase ICEs since checking has been added to TYPE_PRECISION
> macro. check_bitfield_type_and_width is called when attributes haven't
> been applied to the bit-field decl yet and so it still has INTEGER_TYPE
> type, while at finish_struct time it already has VECTOR_TYPE.
>
> The following patch just repeats the check_bitfield_type_and_width
> in there.
>
> Another option would be let handle_vector_size_attribute check for
> bit-fields and error out there.
I think we try to do that there but 8 bits of precision fail to be catched?
Richard
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2025-12-06 Jakub Jelinek <[email protected]>
>
> PR c/123018
> * c-decl.cc (finish_struct): Diagnose bit-fields with vector type.
>
> * gcc.dg/pr123018.c: New test.
>
> --- gcc/c/c-decl.cc.jj 2025-11-24 09:02:57.000000000 +0100
> +++ gcc/c/c-decl.cc 2025-12-05 12:08:16.758425836 +0100
> @@ -9774,6 +9774,13 @@ finish_struct (location_t loc, tree t, t
> unsigned HOST_WIDE_INT width
> = tree_to_uhwi (DECL_INITIAL (field));
> tree type = TREE_TYPE (field);
> + if (VECTOR_TYPE_P (type))
> + {
> + error_at (DECL_SOURCE_LOCATION (field),
> + "bit-field %qD has invalid type", field);
> + type = TREE_TYPE (type);
> + TREE_TYPE (field) = type;
> + }
> if (width != TYPE_PRECISION (type))
> {
> if (TREE_CODE (type) == BITINT_TYPE
> --- gcc/testsuite/gcc.dg/pr123018.c.jj 2025-12-05 12:13:39.681771389 +0100
> +++ gcc/testsuite/gcc.dg/pr123018.c 2025-12-05 12:14:13.889172407 +0100
> @@ -0,0 +1,17 @@
> +/* PR c/123018 */
> +/* { dg-do compile } */
> +
> +struct A {
> + int x : 8 __attribute__ ((vector_size (8))); /* { dg-error "bit-field
> 'x' has invalid type" } */
> +};
> +struct B {
> + float x : 8; /* { dg-error "bit-field 'x' has invalid
> type" } */
> +};
> +struct C {
> + int : 8 __attribute__ ((vector_size (8))); /* { dg-error "bit-field
> '\[^\n\r]*anonymous\[^\n\r]*' has invalid type" } */
> + int x;
> +};
> +struct D {
> + float : 8; /* { dg-error "bit-field
> '\[^\n\r]*anonymous\[^\n\r]*' has invalid type" } */
> + int x;
> +};
>
> Jakub
>
