http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42636
--- Comment #1 from Joern Heissler <gccbugs at joern dot heissler.de> 2011-04-12 21:51:30 UTC --- New compiler output: gcc version 4.5.2 (Debian 4.5.2-8) outputs a new message: $ gcc-4.5 -O -Wuninitialized kr-1-17.c #‘ssa_name’ not supported by pp_c_expression#]’kr-1-17.c: In function ‘main’: kr-1-17.c:12:10: warning: may be used uninitialized in this function gcc version 4.6.1 20110329 (prerelease) (Debian 4.6.0-2) outputs nothing at all. $ gcc-4.6 -O3 -Wall -Wextra -pedantic kr-1-17.c The bug might be fixed in the latest versions. Can anyone please comment on this?