On 2022-12-01 18:19, Kees Cook wrote:
On Thu, Dec 01, 2022 at 10:27:41PM +0000, Qing Zhao wrote:
Hi, Sid,
Thanks a lot for the input.
After more thinking based on your and Kees’ comments, I have the following
thought:
1. -fstrict-flex-arrays=level should control both GCC code gen and warnings
consistently;
2. We need warnings specifically for -fstrict-flex-arrays=level to report any
misuse of flexible
array corresponding to the “level” to gradually encourage language
standard.
So, based on the above two, I think what I did in this current patch is correct:
1. We eliminate the control from -Warray-bounds=level on treating flex arrays,
now only "-fstrict-flex-arrasy=level" controls how the warning treating
the flex arrays.
2. We add a separate new warning -Wstrict-flex-arrays to report any misuse
corresponding to
the different level of -fstrict-flex-arrays.
Although we can certainly merge these new warnings into -Warray-bounds,
however, as Sid mentioned,
-Warray-bounds does issue a lot more warnings than just flexible arrays misuse.
I think it’s necessary
To provide a seperate warning to only issue flexible array misuse.
Let me know if you have any more comments on this.
That's how I understood Richard's comment.
Okay, that seems good. Given that -Warray-bounds is part of -Wall, what
should happen for -Wstrict-flex-arrays=N?
I suppose it would be independent of -Wall, dependent completely on
-fstrict-flex-arrays.
Thanks,
Sid
