http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53880
--- Comment #28 from Steven Bosscher <steven at gcc dot gnu.org> 2012-07-30 14:22:37 UTC --- With -ftrack-macro-expansion=2 (the default): (gdb) call dump_line_table_statistics() Number of expanded macros: 237994 Average number of tokens per macro expansion: 12 Line Table allocations during the compilation process Number of ordinary maps used: 2732 Ordinary map used size: 106k Number of ordinary maps allocated: 6553 Ordinary maps allocated size: 255k Number of macro maps used: 183k Macro maps used size: 7339k Macro maps locations size: 24M Macro maps size: 31M Duplicated maps locations size: 5598k Total allocated maps size: 40M Total used maps size: 31M With -ftrack-macro-expansion=0: (gdb) call dump_line_table_statistics() Number of expanded macros: 233678 Average number of tokens per macro expansion: 13 Line Table allocations during the compilation process Number of ordinary maps used: 2732 Ordinary map used size: 106k Number of ordinary maps allocated: 6553 Ordinary maps allocated size: 255k Number of macro maps used: 0 Macro maps used size: 0 Macro maps locations size: 0 Macro maps size: 0 Duplicated maps locations size: 0 Total allocated maps size: 255k Total used maps size: 106k (The count for number of tokens per macro expansion should be the same, looks like a bug...).