https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109197
David Malcolm <dmalcolm at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|GCC Static Analyzer does |Analyzer gets confused
|not kown `c || b.d` is |about conditionals
|false with the fact that |involving bitfields
|`c=0` and `b.d=0` |
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2023-03-20
--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Thanks for filing this.
Simpler reproducer:
https://godbolt.org/z/qe5cEY9Kh
struct a
{
int d : 10;
} b;
void e()
{
b.d = 0;
if (b.d)
{
__analyzer_eval (b.d);
__analyzer_dump_path ();
}
}
[skipping -Wimplicit-function-declaration warnings]
<source>:11:9: warning: FALSE
11 | __analyzer_eval (b.d);
| ^~~~~~~~~~~~~~~~~~~~~
<source>:12:9: note: path
12 | __analyzer_dump_path ();
| ^~~~~~~~~~~~~~~~~~~~~~~
'e': events 1-3
|
| 9 | if (b.d)
| | ^
| | |
| | (1) following 'true' branch...
| 10 | {
| 11 | __analyzer_eval (b.d);
| | ~~~
| | |
| | (2) ...to here
| 12 | __analyzer_dump_path ();
| | ~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (3) here
|
where it's erronesously considering the case where b.d is 0, but then b.d is
somehow true.
