https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84739
--- Comment #1 from G. Steinmetz <gs...@t-online.de> --- Configured with --enable-checking=yes : $ gcc-8-20180304 -O2 -c z1.c z1.c:1:13: warning: 'baz' alias between functions of incompatible types 'void(void)' and 'void(int, int)' [-Wattribute-alias] static void baz (void) __attribute__((weakref("bar"))); ^~~ z1.c:14:1: note: aliased declaration here bar (int x, int y) ^~~ during GIMPLE pass: tailr z1.c: In function 'bar': z1.c:19:1: internal compiler error: in gimple_call_arg, at gimple.h:3179 } ^ 0xecae86 gimple_call_arg ../../gcc/gimple.h:3179 0xecae86 gimple_call_arg ../../gcc/gimple.h:3187 0xecae86 eliminate_tail_call ../../gcc/tree-tailcall.c:921 0xecae86 optimize_tail_call ../../gcc/tree-tailcall.c:953 0xecae86 tree_optimize_tail_calls_1 ../../gcc/tree-tailcall.c:1082