GSoC: Working on the static analyzer

[Basile Starynkevitch <basile@starynkevitch.net>]

Hello,


Mir Immad asked:

> Should the analyzer warn for code like this "when open fails" (like strchr
> does when  'strchr' returns NULL)
>
> int fd = open("NOFILE", O_RDONLY);
> write(fd, "a", 1);
>
> because of the bad file descriptor.
> unless it is written like this:
> if (!errno)
>    write(fd, "a", 1);

My opinion is yes, in most cases. BTW, the write should fail for a 
read-only file descriptor.


A case (on Linux) where a check is probably not needed: isint 
fd=open("/proc/self/exe", O_RDONLY); or int fd=open ("/dev/random", 
O_RDONLY); done *near the beginning* of main. There are only 
pathological cases where they won't succeed. I suspect that except for 
very critical executable, testing such failures is practically useless.

And your analyzer might start from https://github.com/bstarynk/bismon/ 
or use https://frama-c.com/ <https://frama-c.com/>



PS. My pet project is http://refpersys.org/ (Soon generating code 
compiled by GCC). It is not GCC related.

-- 
Basile Starynkevitch<basile@starynkevitch.net>
(only mine opinions / les opinions sont miennes uniquement)
92340 Bourg-la-Reine, France
web page: starynkevitch.net/Basile/