https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78068
--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #1) > time declaration really is not present in the preprocessed source file. I > can't seem to figure out why it is not though. > > I doubt this is a GCC bug rather than a gdb one (sim is considered part of > gdb) or a glibc one. David asked me to open this bug. It is more an aesthetic issue. Clearly the suggestion "nice" is bogus. I think suggestions should be turned off for -Wimplicit-function-declaration in general. Other compiler turn them off, too. markus@x4 tmp % clang -c emul_unix.i emul_unix.c:818:16: warning: implicit declaration of function 'time' is invalid in C99 [-Wimplicit-function-declaration] time_t now = time ((time_t *)0); ^ 1 warning generated. markus@x4 tmp % icc -c emul_unix.i emul_unix.c(818): warning #266: function "time" declared implicitly time_t now = time ((time_t *)0); ^