Re: may be a buffer overflow problem

On 18.06.24 04:35, Andres Freund wrote:
> On 2024-06-17 23:52:54 +0200, Daniel Gustafsson wrote:
>> Since sqlca is, according to our docs, present in other database systems we
>> should probably keep it a 5-char array for portability reasons.  Adding a
>> padding character should be fine though.
> 
> How about, additionally, adding __attribute__((nonstring))? Wrapped in an
> attribute, of course.  That'll trigger warning for many unsafe uses, like
> strlen().
> 
> It doesn't quite detect the problematic case in ecpg_log() though, seems it
> doesn't understand fprintf() well enough (it does trigger in simple printf()
> cases, because they get reduced to puts(), which it understands).

See also <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115513>.

> Adding nonstring possibly allow us to re-enable -Wstringop-truncation,

Note that that would only work because we now always use our own 
snprintf(), which is not covered by that option.  I mean, we could still 
do it, but it's not like the reasons we originally disabled that option 
have actually gone away.