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| author | Jakub Jelinek <jakub@redhat.com> | 2023-03-14 16:17:32 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2023-03-14 16:17:32 +0100 |
| commit | c35cf160a0ed81570cff6600dba465cf95fa80fa (patch) | |
| tree | 81d3ab44a48fc02958b1c4af22d7b1943cfcb8a1 | |
| parent | 0e6f87835ccabfe84afe412583544ff6e6292352 (diff) | |
| download | gcc-c35cf160a0ed81570cff6600dba465cf95fa80fa.zip gcc-c35cf160a0ed81570cff6600dba465cf95fa80fa.tar.gz gcc-c35cf160a0ed81570cff6600dba465cf95fa80fa.tar.bz2 | |
c++: Treat unnamed bitfields as padding for __has_unique_object_representations [PR109096]
As reported in the PR, for __has_unique_object_representations we
were treating unnamed bitfields as named ones, which is wrong, they
are actually padding.
THe following patch fixes that.
2023-03-14 Jakub Jelinek <jakub@redhat.com>
PR c++/109096
* tree.cc (record_has_unique_obj_representations): Ignore unnamed
bitfields.
* g++.dg/cpp1z/has-unique-obj-representations3.C: New test.
| -rw-r--r-- | gcc/cp/tree.cc | 4 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp1z/has-unique-obj-representations3.C | 10 |
2 files changed, 12 insertions, 2 deletions
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index de83d41..16b8fcb 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -4851,7 +4851,7 @@ record_has_unique_obj_representations (const_tree t, const_tree sz) DECL_SIZE (field))) return false; } - else if (DECL_C_BIT_FIELD (field)) + else if (DECL_C_BIT_FIELD (field) && !DECL_UNNAMED_BIT_FIELD (field)) { tree btype = DECL_BIT_FIELD_TYPE (field); if (!type_has_unique_obj_representations (btype)) @@ -4862,7 +4862,7 @@ record_has_unique_obj_representations (const_tree t, const_tree sz) offset_int cur = 0; for (tree field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) - if (TREE_CODE (field) == FIELD_DECL) + if (TREE_CODE (field) == FIELD_DECL && !DECL_UNNAMED_BIT_FIELD (field)) { offset_int fld = wi::to_offset (DECL_FIELD_OFFSET (field)); offset_int bitpos = wi::to_offset (DECL_FIELD_BIT_OFFSET (field)); diff --git a/gcc/testsuite/g++.dg/cpp1z/has-unique-obj-representations3.C b/gcc/testsuite/g++.dg/cpp1z/has-unique-obj-representations3.C new file mode 100644 index 0000000..349c93e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/has-unique-obj-representations3.C @@ -0,0 +1,10 @@ +// PR c++/109096 +// { dg-do compile { target c++11 } } + +#define INTB (__SIZEOF_INT__ * __CHAR_BIT__) +struct U { int i : INTB * 3 / 4; int : INTB / 4; }; +struct V { int : INTB * 3 / 4; int j : INTB / 4; }; +struct W { int i; int : 0; int j; }; +static_assert (__has_unique_object_representations (U) == false, ""); +static_assert (__has_unique_object_representations (V) == false, ""); +static_assert (sizeof (W) != 2 * sizeof (int) || __has_unique_object_representations (W) == true, ""); |