On 11/07/2016 23:28, Emil Velikov wrote:
On 10 July 2016 at 10:00, Quentin Glidic
<[email protected]> wrote:
From: Quentin Glidic <[email protected]>
clients/terminal.c: In function 'redraw_handler':
clients/terminal.c:213:28: warning: 'machine.unicode' may be used
uninitialized in this function [-Wmaybe-uninitialized]
struct utf8_state_machine machine;
^~~~~~~
clients/terminal.c: In function 'handle_char':
clients/terminal.c:213:28: warning: 'machine.unicode' may be used
uninitialized in this function [-Wmaybe-uninitialized]
Warning produced by GCC 5.3 and 6.1, with -O3.
Signed-off-by: Quentin Glidic <[email protected]>
---
You have to look at the file directly to completely understand this one.
Not sure that is the value to return in this case, but at least it
silences the warning.
::unicode will never be read (get_unicode) when it's invalid, since
::state will equal to utf8state_reject (as set in utf8_next_char).
Seems like the compiler/optimiser cannot see that far, thus throws a
warning message.
With anything vaguely like the above in the commit message, the patch is
Reviewed-by: Emil Velikov <[email protected]>
I found it weird that the compiler wouldn’t see that, so I re-checked
the code.
I think with -O3, this specific "for" is compile-time unlooped, and
utf8_next_char inlined.
And there is *one* path that can keep machine.state to utf8state_start,
thus triggering the warning.
Without -O3, the function is globally tagged as “changing unicode”, so
no warning is produced.
I will let the pusher to choose what to include in the commit message,
as I find the wording “silence” (and not “fix”) clear enough, though in
this specific case, it could need an actual fix.
Side note: I picked 0 as the default value, but maybe in this case
0xfffd would be better?
Cheers,
--
Quentin “Sardem FF7” Glidic
_______________________________________________
wayland-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/wayland-devel
