Re: Too many warnings building Emacs with GCC 6 on MSYS2-MinGW64

[Eli Zaretskii <eliz@gnu.org>]

> Cc: kbrown@cornell.edu, emacs-devel@gnu.org
> From: Angelo Graziosi <angelo.graziosi@alice.it>
> Date: Thu, 1 Sep 2016 09:44:59 +0200
> 
> > Thanks.  What happens if you remove the unistd.h inclusion?
> >
> 
> It builds without warnings. So the simplest test case is:
> 
> 
> extern int execve (const char *, char * const *, char * const *);
> 
> int main()
> {
>    return 0;
> }

Thanks, I made the changes on the master branch that are supposed to
fix the warnings.  Please test.

The prototype that fixes this, with 'int' as the return value, is
wrong, and is IMO a MinGW64 GCC bug which should be reported.
intptr_t is a 64-bit type in MinGW64, while int is still 32 bits.  By
enforcing the wrong type, GCC contradicts MinGW64's own library
headers.

Btw, another possibility to avoid the warnings would be to use the GCC
option -fno-builtin-execve.  Can you try that (with the previous
prototype)?