The warnings printed by the linker are very handy, and it's not a
local customization either.. it's just not very widely utilized.

/usr/include/`uname -m`/cdefs.h determines if GCC is being used and
defines __warn_references as follows:

#define __warn_references(sym,msg) \
__asm__(".section .gnu.warning." __STRING(sym) \
" ; .ascii \"" msg "\" ; .text")
#endif

Then, in strcpy.c for instance, the C preprocessor first checks to see
if APIWARN is defined, and if it is, the function is marked as unsafe.

#if defined(APIWARN)
__warn_references(strcpy,
"warning: strcpy() is almost always misused, please use strlcpy()");
#endif

Personally, I think it's a brilliant idea.. but this reminds me,
several files don't define that...

/usr/src/lib/libc/stdio/gets.c
/usr/src/lib/libc/stdio/mktemp.c
/usr/src/lib/libc/stdio/tempnam.c
/usr/src/lib/libc/stdio/tmpnam.c
/usr/src/lib/libc/compat-43/getwd.c
/usr/src/lib/libcompat/4.3/setruid.c
/usr/src/lib/libcompat/4.3/setrgid.c

I'm not sure if that was the intent of the developers, or if it was an
oversight.. regardless I'll send patches if anyone wants them.

Be well. 8)

On 6/24/08, Brynet <brynet@gmail.com> wrote:
> Personally, I think it's a brilliant idea.. but this reminds me,
> several files don't define that...
>
> /usr/src/lib/libc/stdio/gets.c
> /usr/src/lib/libc/stdio/mktemp.c

Some warnings are not optional.