http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56746
--- Comment #11 from Mathias Gaunard <mathias at gaunard dot com> --- 4.8.1 is still affected by this. I wouldn't say it's NOTABUG if a new diagnostic feature enabled by default increases memory consumption by 50%, even when no diagnostic is emitted. I cannot easily give a test case; the problem being preprocessor-related, the issues disappear once preprocessed. The code incriminated includes hundreds of files (if not more), split in about 20 different include directories. Those files contain templates instantiated hundreds of times each, and their body is generated by macros which may end up creating lines that are thousands of characters long.