1 /* $NetBSD: msg_217.c,v 1.12 2023/07/07 19:45:22 rillig Exp $ */ 2 # 3 "msg_217.c" 3 4 // Test for message: function '%s' falls off bottom without returning value [217] 5 6 /* lint1-extra-flags: -X 351 */ 7 8 int 9 random(int n) 10 { 11 if (n < 0) 12 return -3; 13 } 14 /* expect-1: warning: function 'random' falls off bottom without returning value [217] */ 15 16 /* 17 * The pattern 'do { } while (0)' is often used in statement macros. 18 * Putting a 'return' at the end of such a macro is legitimate, the embracing 19 * 'do { } while (0)' is probably there to conform to a coding standard or 20 * to otherwise reduce confusion. 21 * 22 * Seen in external/bsd/libevent/dist/event_tagging.c, function 23 * encode_int_internal. 24 * 25 * Before tree.c 1.243 from 2021-03-21, lint wrongly reported that the 26 * 'while 0' was unreachable. This has been fixed by allowing the 'while 0' 27 * in a do-while-false loop to be unreachable. The same could be useful for a 28 * do-while-true. 29 * 30 * Before func.c 1.83 from 2021-03-21, lint wrongly reported that the function 31 * would fall off the bottom. 32 */ 33 int 34 do_while_return(int i) 35 { 36 do { 37 return i; 38 } while (0); 39 } 40 41 /* 42 * C99 5.1.2.2.3 "Program termination" p1 defines that as a special exception, 43 * the function 'main' does not have to return a value, reaching the bottom 44 * is equivalent to returning 0. 45 * 46 * Before func.c 1.72 from 2021-02-21, lint had wrongly warned about this. 47 */ 48 int 49 main(void) 50 { 51 } 52 53 int 54 reachable_continue_leads_to_endless_loop(void) 55 { 56 for (;;) { 57 if (1) 58 continue; 59 break; 60 } 61 } 62 63 int 64 unreachable_continue_falls_through(void) 65 { 66 for (;;) { 67 if (0) 68 /* expect+1: warning: statement not reached [193] */ 69 continue; 70 break; 71 } 72 } 73 /* expect-1: warning: function 'unreachable_continue_falls_through' falls off bottom without returning value [217] */ 74