https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114986
Bug ID: 114986
Summary: Seemingly incorrect "ignoring packed attribute"
warning
Product: gcc
Version: 14.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: pdimov at gmail dot com
Target Milestone: ---
The following program
```
#include <cstdint>
#include <cstddef>
struct uuid
{
std::uint8_t data[ 16 ] = {};
};
struct __attribute__((packed)) X
{
uuid a;
unsigned char b;
unsigned c;
unsigned char d;
};
static_assert( offsetof(X, c) == 17 );
static_assert( sizeof(X) == 22 );
```
(https://godbolt.org/z/WvxjM3eqn)
gives
```
<source>:11:10: warning: ignoring packed attribute because of unpacked non-POD
field 'uuid X::a'
```
However, the attribute is applied, because the static assertions pass.
If `__attribute__((packed))` is removed, the assertions (correctly) fail
(https://godbolt.org/z/hP4oG98fq).
Therefore, the warning seems wrong.
GCC 14, 13, 12 warn; 11 and earlier do not.
