https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118135
Bug ID: 118135
Summary: undefined std::bit_cast for bool is not detected
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
Target Milestone: ---
Take:
```
#include <bit>
auto c = (char)('A'&~0x1);
int main()
{
bool t1 = std::bit_cast<bool>(c);
__builtin_printf("%s\n", t1 ? "true" : "false");
}
```
-fsanitize=undefined should detect an invalid value for bool but currently does
not.
If we do:
```
#include <bit>
auto c = (char)('A'&~0x1);
bool t;
int main()
{
bool t1 = std::bit_cast<bool>(c);
t = t1;
__builtin_printf("%s\n", t ? "true" : "false");
}
```
Then GCC is able to detect it.
