Re: [fetchmail-devel] [PATCH] printf ( #ifdef ... #endif ... )

[Miloslav T. <mi...@re...>]

Hello,
Matthias Andree wrote:
> Miloslav Trmac <mi...@re...> writes:
>>printf () may be a macro (and it actually is a macro e.g. with recent
>>glibc and -D_FORTIFY_SOURCE=2) and preprocessor directives within
>>macros are not permitted.
> 
> What is this _FORTIFY_SOURCE about?  I have it in my include files, but
> ZERO documentation, and all I found out is that it remaps to ominuous
> builtins. So there must be recent gcc as well as it appears.
http://www.redhat.com/magazine/009jul05/features/execshield/#checks
contains a short introduction; basically buffer sizes, when known
to the compiler, are passed to libc and libc aborts the program if
it would overwrite the buffer.

> If this is supposed to be a security helper/feature/whatever and it's
> not documented, it's useless.
The necessary features have not been released in gcc yet (they
are scheduled to be in gcc 4.1); currently this requires using
the Fedora/RHEL toolchain, so evangelizing this for cross-distribution
usage would be a bit premature.
	Mirek