/* $NetBSD: msg_217.c,v 1.16 2024/11/30 11:27:20 rillig Exp $ */ # 3 "msg_217.c" // Test for message: function '%s' falls off bottom without returning value [217] /* lint1-extra-flags: -X 351 */ int random(int n) { if (n < 0) return -3; } /* expect-1: warning: function 'random' falls off bottom without returning value [217] */ /* * The pattern 'do { } while (0)' is often used in statement macros. * Putting a 'return' at the end of such a macro is legitimate, the embracing * 'do { } while (0)' is probably there to conform to a coding standard or * to otherwise reduce confusion. * * Seen in external/bsd/libevent/dist/event_tagging.c, function * encode_int_internal. * * Before tree.c 1.243 from 2021-03-21, lint wrongly reported that the * 'while 0' was unreachable. This has been fixed by allowing the 'while 0' * in a do-while-false loop to be unreachable. The same could be useful for a * do-while-true. * * Before func.c 1.83 from 2021-03-21, lint wrongly reported that the function * would fall off the bottom. */ int do_while_return(int i) { do { return i; } while (0); } /* * C99 5.1.2.2.3 "Program termination" p1 defines that as a special exception, * the function 'main' does not have to return a value, reaching the bottom * is equivalent to returning 0. * * Before func.c 1.72 from 2021-02-21, lint had wrongly warned about this. */ int main(void) { } int reachable_continue_leads_to_endless_loop(void) { for (;;) { if (1) continue; break; } } int unreachable_continue_falls_through(void) { for (;;) { if (0) /* expect+1: warning: 'continue' statement not reached [193] */ continue; break; } } /* expect-1: warning: function 'unreachable_continue_falls_through' falls off bottom without returning value [217] */ _Noreturn void noreturn_c11(void); [[noreturn]] void noreturn_c23(void); __attribute__((__noreturn__)) void noreturn_gnu_prefix(void); void __attribute__((__noreturn__)) noreturn_gnu_infix(void); void noreturn_gnu_suffix(void) __attribute__((__noreturn__)); int call_noreturn_c11(void) { noreturn_c11(); } inline int call_noreturn_c23(void) { noreturn_c23(); } int call_noreturn_gnu_prefix(void) { noreturn_gnu_prefix(); } int call_noreturn_gnu_infix(void) { noreturn_gnu_infix(); } int call_noreturn_gnu_suffix(void) { noreturn_gnu_suffix(); } double *force_function_attributes_in_diagnostic[] = { // Force the word 'noreturn' to occur in a diagnostic. /* expect+1: warning: illegal combination of 'pointer to double' and 'pointer to noreturn function(void) returning void', op 'init' [124] */ noreturn_c23, // The 'inline' does affect the type of the function. /* expect+1: warning: illegal combination of 'pointer to double' and 'pointer to function(void) returning int', op 'init' [124] */ call_noreturn_c23, };