[Bug libstdc++/51785] gets not anymore declared

[bkoz at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51785

--- Comment #19 from Benjamin Kosnik <bkoz at gcc dot gnu.org> 2012-03-01 00:21:11 UTC ---
Created attachment 26794
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26794
gets conditionally declared/used


Here's a way to deal with gets that is pretty simple. If it's around at
configure time, it's used. If not, it's dropped from <cstdio>. This uses the
same configure bits and approach used for math.

This should prevent any compile error at bootstrap time. That seems sufficient
for gcc-4.7 release. RMs?

Note, I'm on f17 and I'm not running into this during make/check of trunk gcc. 
If somebody can give me self-contained sources that fail on f17 it would be
appreciated.

Please don't put in GLIBC macros to cstdio. Boo.

Instead, if you need to layer on a glibc part to this, you should start with
this patch, and then conditionally define/undefine _GLIBCXX_HAVE_GETS in 

libstdc++-v3/config/os/gnu-linux/os_defines.h

based on the glibc prerequisites and version checks.

-benjamin