/*      $NetBSD: d_c99_bool.c,v 1.11 2023/07/03 09:37:14 rillig Exp $   */
# 3 "d_c99_bool.c"

/*
 * C99 6.3.1.2 says: "When any scalar value is converted to _Bool, the result
 * is 0 if the value compares equal to 0; otherwise the result is 1."
 *
 * This is different from the other integer types, which get truncated or
 * invoke undefined behavior.
 */

/* lint1-extra-flags: -X 351 */

/* expect+1: error: negative array dimension (-2) [20] */
int int_0[(_Bool)0 ? -1 : -2];

/* expect+1: error: negative array dimension (-1) [20] */
int int_1[(_Bool)1 ? -1 : -2];

/* expect+1: error: negative array dimension (-1) [20] */
int int_2[(_Bool)2 ? -1 : -2];

/* expect+1: error: negative array dimension (-1) [20] */
int int_256[(_Bool)256 ? -1 : -2];

/* expect+1: error: negative array dimension (-2) [20] */
int null_pointer[(_Bool)(void *)0 ? -1 : -2];

/*
 * XXX: In initializers for global variables, taking the address of a variable
 * is allowed and may be modified by a constant offset.  This is not a constant
 * expression though.
 *
 * In such a case, the grammar rule array_size_opt calls to_int_constant, which
 * returns 1 for the array size without reporting an error.  This is why
 * neither of the following array declarations generates an error message.
 */
char ch;
int nonnull_pointer_converts_to_false[(_Bool)&ch ? -1 : 1];
int nonnull_pointer_converts_to_true_[(_Bool)&ch ? 1 : -1];

/* expect+1: error: negative array dimension (-1) [20] */
int double_minus_1_0[(_Bool)-1.0 ? -1 : -2];

/* expect+1: error: negative array dimension (-1) [20] */
int double_minus_0_5[(_Bool)-0.5 ? -1 : -2];

/* expect+1: error: negative array dimension (-2) [20] */
int double_minus_0_0[(_Bool)-0.0 ? -1 : -2];

/* expect+1: error: negative array dimension (-2) [20] */
int double_0_0[(_Bool)0.0 ? -1 : -2];

/* The C99 rationale explains in 6.3.1.2 why (_Bool)0.5 is true. */
/* expect+1: error: negative array dimension (-1) [20] */
int double_0_5_converts_to_false[(_Bool)0.5 ? -1 : -2];

/* expect+1: error: negative array dimension (-1) [20] */
int double_1_0_converts_to_false[(_Bool)1.0 ? -1 : -2];

_Bool
convert_to_bool(int selector)
{
        static struct variant {
                _Bool b;
                char c;
                int i;
                double d;
                enum color {
                        RED
                } e;
                const char *pcc;
                void (*f)(void);
                double _Complex dc;
        } v = { .i = 0 };

        switch (selector) {
        case 0: return v.b;
        case 1: return v.c;
        case 2: return v.i;
        case 3: return v.d;
        case 4: return v.e;
        case 5: return v.pcc;
        case 6: return v.f;
        case 7: return v.dc;
        default: return v.b;
        }
}