http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57653
--- Comment #2 from Allan McRae <allan at archlinux dot org> ---
# echo "int main() { return }" > foo.c
# touch foo.h
# gcc -imacros foo.h foo.c
<command-line>: In function ‘main’:
<command-line>:1:21: error: expected expression before ‘}’ token
