diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2021-08-25 22:35:21 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2021-08-25 22:35:57 +0200 |
| commit | 1ab84eda5548119908c4e24c6ad953dd7c00a5b7 (patch) | |
| tree | c3775826d008eb9bf901d8ce4c35f98bec0415a0 | |
| parent | 5c85f29537662f1f4195a102cbf0182ffa32d8ac (diff) | |
| download | gcc-1ab84eda5548119908c4e24c6ad953dd7c00a5b7.zip gcc-1ab84eda5548119908c4e24c6ad953dd7c00a5b7.tar.gz gcc-1ab84eda5548119908c4e24c6ad953dd7c00a5b7.tar.bz2 | |
c++: Fix up value initialization of structs with zero width bitfields [PR102019]
The removal of remove_zero_width_bit_fields, in addition to triggering
some ABI issues that need solving anyway (ABI incompatibility between
C and C++) also resulted in UB inside of gcc, we now call build_zero_init
which calls build_int_cst on an integral type with TYPE_PRECISION of 0.
Fixed by ignoring the zero width bitfields. I understand
build_value_init_noctor wants to initialize to 0 even unnamed bitfields
(of non-zero width), at least until we have some CONSTRUCTOR flag that says
that even all the padding bits should be cleared.
2021-08-25 Jakub Jelinek <jakub@redhat.com>
PR c++/102019
* init.c (build_value_init_noctor): Ignore unnamed zero-width
bitfields.
| -rw-r--r-- | gcc/cp/init.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gcc/cp/init.c b/gcc/cp/init.c index 229c84e..1426f9a 100644 --- a/gcc/cp/init.c +++ b/gcc/cp/init.c @@ -427,6 +427,11 @@ build_value_init_noctor (tree type, tsubst_flags_t complain) == NULL_TREE)) continue; + /* Ignore unnamed zero-width bitfields. */ + if (DECL_UNNAMED_BIT_FIELD (field) + && integer_zerop (DECL_SIZE (field))) + continue; + /* We could skip vfields and fields of types with user-defined constructors, but I think that won't improve performance at all; it should be simpler in general just |