1 1.8 rillig /* $NetBSD: d_c99_bool.c,v 1.8 2022/01/15 14:22:03 rillig Exp $ */ 2 1.5 rillig # 3 "d_c99_bool.c" 3 1.1 rillig 4 1.1 rillig /* 5 1.1 rillig * C99 6.3.1.2 says: "When any scalar value is converted to _Bool, the result 6 1.1 rillig * is 0 if the value compares equal to 0; otherwise the result is 1." 7 1.1 rillig * 8 1.1 rillig * This is different from the other integer types, which get truncated or 9 1.1 rillig * invoke undefined behavior. 10 1.1 rillig */ 11 1.1 rillig 12 1.7 rillig /* Below, each false statement produces "negative array dimension" [20]. */ 13 1.1 rillig 14 1.1 rillig int int_0_converts_to_false[(_Bool)0 ? -1 : 1]; 15 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 16 1.8 rillig int int_0_converts_to_true_[(_Bool)0 ? 1 : -1]; 17 1.1 rillig 18 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 19 1.8 rillig int int_1_converts_to_false[(_Bool)1 ? -1 : 1]; 20 1.1 rillig int int_1_converts_to_true_[(_Bool)1 ? 1 : -1]; 21 1.1 rillig 22 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 23 1.8 rillig int int_2_converts_to_false[(_Bool)2 ? -1 : 1]; 24 1.1 rillig int int_2_converts_to_true_[(_Bool)2 ? 1 : -1]; 25 1.1 rillig 26 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 27 1.8 rillig int int_256_converts_to_false[(_Bool)256 ? -1 : 1]; 28 1.3 rillig int int_256_converts_to_true_[(_Bool)256 ? 1 : -1]; 29 1.1 rillig 30 1.1 rillig int null_pointer_converts_to_false[(_Bool)(void *)0 ? -1 : 1]; 31 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 32 1.8 rillig int null_pointer_converts_to_true_[(_Bool)(void *)0 ? 1 : -1]; 33 1.1 rillig 34 1.5 rillig /* 35 1.5 rillig * XXX: lint does not treat the address of a global variable as a constant 36 1.5 rillig * expression. This goes against C99 6.6p7 but is probably not too relevant 37 1.5 rillig * in practice. 38 1.5 rillig * 39 1.5 rillig * The call to constant(tn, 0) defaults to 1, then. This is why neither of 40 1.5 rillig * the following array declarations generates an error message. 41 1.5 rillig */ 42 1.5 rillig char ch; 43 1.5 rillig int nonnull_pointer_converts_to_false[(_Bool)&ch ? -1 : 1]; 44 1.5 rillig int nonnull_pointer_converts_to_true_[(_Bool)&ch ? 1 : -1]; 45 1.1 rillig 46 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 47 1.8 rillig int double_minus_1_0_converts_to_false[(_Bool)-1.0 ? -1 : 1]; 48 1.3 rillig int double_minus_1_0_converts_to_true_[(_Bool)-1.0 ? 1 : -1]; 49 1.1 rillig 50 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 51 1.8 rillig int double_minus_0_5_converts_to_false[(_Bool)-0.5 ? -1 : 1]; 52 1.3 rillig int double_minus_0_5_converts_to_true_[(_Bool)-0.5 ? 1 : -1]; 53 1.1 rillig 54 1.1 rillig int double_minus_0_0_converts_to_false[(_Bool)-0.0 ? -1 : 1]; 55 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 56 1.8 rillig int double_minus_0_0_converts_to_true_[(_Bool)-0.0 ? 1 : -1]; 57 1.1 rillig 58 1.1 rillig int double_0_0_converts_to_false[(_Bool)0.0 ? -1 : 1]; 59 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 60 1.8 rillig int double_0_0_converts_to_true_[(_Bool)0.0 ? 1 : -1]; 61 1.1 rillig 62 1.1 rillig /* The C99 rationale explains in 6.3.1.2 why (_Bool)0.5 is true. */ 63 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 64 1.8 rillig int double_0_5_converts_to_false[(_Bool)0.5 ? -1 : 1]; 65 1.3 rillig int double_0_5_converts_to_true_[(_Bool)0.5 ? 1 : -1]; 66 1.1 rillig 67 1.8 rillig /* expect+1: error: negative array dimension (-1) [20] */ 68 1.8 rillig int double_1_0_converts_to_false[(_Bool)1.0 ? -1 : 1]; 69 1.1 rillig int double_1_0_converts_to_true_[(_Bool)1.0 ? 1 : -1]; 70 1.2 rillig 71 1.2 rillig _Bool 72 1.2 rillig bool_to_bool(_Bool b) 73 1.2 rillig { 74 1.2 rillig return b; 75 1.2 rillig } 76 1.2 rillig 77 1.2 rillig _Bool 78 1.2 rillig char_to_bool(char c) 79 1.2 rillig { 80 1.2 rillig return c; 81 1.2 rillig } 82 1.2 rillig 83 1.2 rillig _Bool 84 1.2 rillig int_to_bool(int i) 85 1.2 rillig { 86 1.2 rillig return i; 87 1.2 rillig } 88 1.2 rillig 89 1.2 rillig _Bool 90 1.2 rillig double_to_bool(double d) 91 1.2 rillig { 92 1.2 rillig return d; 93 1.2 rillig } 94 1.2 rillig 95 1.2 rillig enum color { 96 1.2 rillig RED 97 1.2 rillig }; 98 1.2 rillig 99 1.2 rillig _Bool 100 1.2 rillig enum_to_bool(enum color e) 101 1.2 rillig { 102 1.2 rillig return e; 103 1.2 rillig } 104 1.2 rillig 105 1.2 rillig _Bool 106 1.2 rillig pointer_to_bool(const char *p) 107 1.2 rillig { 108 1.4 rillig return p; 109 1.2 rillig } 110 1.2 rillig 111 1.2 rillig _Bool 112 1.2 rillig function_pointer_to_bool(void (*f)(void)) 113 1.2 rillig { 114 1.4 rillig return f; 115 1.2 rillig } 116 1.2 rillig 117 1.2 rillig _Bool 118 1.2 rillig complex_to_bool(double _Complex c) 119 1.2 rillig { 120 1.2 rillig return c; 121 1.2 rillig } 122