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| author | Jakub Jelinek <jakub@redhat.com> | 2020-11-25 10:37:58 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-11-25 10:37:58 +0100 |
| commit | a7285c8659689e9ade53fcb996b26d874455a4f3 (patch) | |
| tree | 5db8400816f1cad1b376e8d8f448dfef057be0fa /gcc/gimple-fold.c | |
| parent | 1e2c9a2761097a6758b6aaaf612d629aa7e9febf (diff) | |
| download | gcc-a7285c8659689e9ade53fcb996b26d874455a4f3.zip gcc-a7285c8659689e9ade53fcb996b26d874455a4f3.tar.gz gcc-a7285c8659689e9ade53fcb996b26d874455a4f3.tar.bz2 | |
middle-end: Reject flexible array members in __builtin_clear_padding [PR97943]
As mentioned in the PR, we currently ICE on flexible array members in
structs and unions during __builtin_clear_padding processing.
Jason said in the PR he'd prefer an error in these cases over forcefully
handling it as [0] arrays (everything is padding then) or consider the
arrays to have as many whole elements as would fit into the tail padding.
So, this patch implements that.
2020-11-25 Jakub Jelinek <jakub@redhat.com>
PR middle-end/97943
* gimple-fold.c (clear_padding_union, clear_padding_type): Error on and
ignore flexible array member fields. Ignore fields with
error_mark_node type.
* c-c++-common/builtin-clear-padding-2.c: New test.
* c-c++-common/builtin-clear-padding-3.c: New test.
* g++.dg/ext/builtin-clear-padding-1.C: New test.
* gcc.dg/builtin-clear-padding-2.c: New test.
Diffstat (limited to 'gcc/gimple-fold.c')
| -rw-r--r-- | gcc/gimple-fold.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 905c0a0..1f0a6097 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -4329,6 +4329,17 @@ clear_padding_union (clear_padding_struct *buf, tree type, HOST_WIDE_INT sz) for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL) { + if (DECL_SIZE_UNIT (field) == NULL_TREE) + { + if (TREE_TYPE (field) == error_mark_node) + continue; + gcc_assert (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE + && !COMPLETE_TYPE_P (TREE_TYPE (field))); + error_at (buf->loc, "flexible array member %qD does not have " + "well defined padding bits for %qs", + field, "__builtin_clear_padding"); + continue; + } HOST_WIDE_INT fldsz = tree_to_shwi (DECL_SIZE_UNIT (field)); gcc_assert (union_buf->size == 0); union_buf->off = start_off; @@ -4446,11 +4457,12 @@ clear_padding_type (clear_padding_struct *buf, tree type, HOST_WIDE_INT sz) for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL) { + tree ftype = TREE_TYPE (field); if (DECL_BIT_FIELD (field)) { if (DECL_NAME (field) == NULL_TREE) continue; - HOST_WIDE_INT fldsz = TYPE_PRECISION (TREE_TYPE (field)); + HOST_WIDE_INT fldsz = TYPE_PRECISION (ftype); if (fldsz == 0) continue; HOST_WIDE_INT pos = int_byte_position (field); @@ -4513,6 +4525,16 @@ clear_padding_type (clear_padding_struct *buf, tree type, HOST_WIDE_INT sz) } } } + else if (DECL_SIZE_UNIT (field) == NULL_TREE) + { + if (ftype == error_mark_node) + continue; + gcc_assert (TREE_CODE (ftype) == ARRAY_TYPE + && !COMPLETE_TYPE_P (ftype)); + error_at (buf->loc, "flexible array member %qD does not have " + "well defined padding bits for %qs", + field, "__builtin_clear_padding"); + } else { HOST_WIDE_INT pos = int_byte_position (field); |