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msg_166.c revision 1.2 
      1  1.2  rillig /*	$NetBSD: msg_166.c,v 1.2 2021/01/31 13:11:08 rillig Exp $	*/
      2  1.1  rillig # 3 "msg_166.c"
      3  1.1  rillig 
      4  1.1  rillig // Test for message: precision lost in bit-field assignment [166]
      5  1.1  rillig 
      6  1.2  rillig /* lint1-extra-flags: -hp */
      7  1.2  rillig 
      8  1.2  rillig struct bit_set {
      9  1.2  rillig 
     10  1.2  rillig 	/*
     11  1.2  rillig 	 * C99 6.7.2p5 and 6.7.2.1p9 footnote 104 say that for bit-fields of
     12  1.2  rillig 	 * underlying type 'int', "it is implementation-defined whether the
     13  1.2  rillig 	 * specifier 'int' designates the same type as 'signed int' or the
     14  1.2  rillig 	 * same type as 'unsigned int'".
     15  1.2  rillig 	 *
     16  1.2  rillig 	 * https://gcc.gnu.org/onlinedocs/gcc/Structures-unions-enumerations
     17  1.2  rillig 	 * -and-bit-fields-implementation.html says: "By default it is treated
     18  1.2  rillig 	 * as 'signed int' but this may be changed by the
     19  1.2  rillig 	 * '-funsigned-bitfields' option".
     20  1.2  rillig 	 *
     21  1.2  rillig 	 * Clang doesn't document implementation-defined behavior, see
     22  1.2  rillig 	 * https://bugs.llvm.org/show_bug.cgi?id=11272.
     23  1.2  rillig 	 */
     24  1.2  rillig 
     25  1.2  rillig 	int minus_1_to_0: 1;		/* expect: 34 */
     26  1.2  rillig 	int minus_8_to_7: 4;		/* expect: 34 */
     27  1.2  rillig 	unsigned zero_to_1: 1;
     28  1.2  rillig 	unsigned zero_to_15: 4;
     29  1.2  rillig };
     30  1.2  rillig 
     31  1.2  rillig void example(void) {
     32  1.2  rillig 	struct bit_set bits;
     33  1.2  rillig 
     34  1.2  rillig 	/* Clang doesn't warn about the 1. */
     35  1.2  rillig 	bits.minus_1_to_0 = -2;		/* expect: 166 */
     36  1.2  rillig 	bits.minus_1_to_0 = -1;
     37  1.2  rillig 	bits.minus_1_to_0 = 0;
     38  1.2  rillig 	bits.minus_1_to_0 = 1;		/* expect: 166 */
     39  1.2  rillig 	bits.minus_1_to_0 = 2;		/* expect: 166 */
     40  1.2  rillig 
     41  1.2  rillig 	bits.minus_8_to_7 = -9;		/* expect: 166 */
     42  1.2  rillig 	bits.minus_8_to_7 = -8;
     43  1.2  rillig 	bits.minus_8_to_7 = 7;
     44  1.2  rillig 	bits.minus_8_to_7 = 8;		/* expect: 166 */
     45  1.2  rillig 
     46  1.2  rillig 	/* Clang doesn't warn about the -1. */
     47  1.2  rillig 	bits.zero_to_1 = -2;		/* expect: 164 */
     48  1.2  rillig 	bits.zero_to_1 = -1;		/* expect: 164 */
     49  1.2  rillig 	bits.zero_to_1 = 0;
     50  1.2  rillig 	bits.zero_to_1 = 1;
     51  1.2  rillig 	bits.zero_to_1 = 2;		/* expect: 166 */
     52  1.2  rillig 
     53  1.2  rillig 	/* Clang doesn't warn about the -8. */
     54  1.2  rillig 	bits.zero_to_15 = -9;		/* expect: 164 */
     55  1.2  rillig 	bits.zero_to_15 = -8;		/* expect: 164 */
     56  1.2  rillig 	bits.zero_to_15 = 0;
     57  1.2  rillig 	bits.zero_to_15 = 15;
     58  1.2  rillig 	bits.zero_to_15 = 16;		/* expect: 166 */
     59  1.2  rillig }
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