https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61861
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> --- It looks like a pretty old issue. E.g. on void foo (void) { __FILE__; "foo"; } 4.8 says: r.c: In function ‘foo’: r.c:4:1: warning: statement with no effect [-Wunused-value] __FILE__; ^ r.c:5:3: warning: statement with no effect [-Wunused-value] "foo"; ^ See how that first caret is off. I have an untested patch that should fix this.