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msg_166.c revision 1.4 
      1  1.4  rillig /*	$NetBSD: msg_166.c,v 1.4 2022/06/16 16:58:36 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  1.4  rillig 	/* expect+1: warning: bit-field of type plain 'int' has implementation-defined signedness [344] */
     26  1.4  rillig 	int minus_1_to_0: 1;
     27  1.4  rillig 	/* expect+1: warning: bit-field of type plain 'int' has implementation-defined signedness [344] */
     28  1.4  rillig 	int minus_8_to_7: 4;
     29  1.2  rillig 	unsigned zero_to_1: 1;
     30  1.2  rillig 	unsigned zero_to_15: 4;
     31  1.2  rillig };
     32  1.2  rillig 
     33  1.2  rillig void example(void) {
     34  1.2  rillig 	struct bit_set bits;
     35  1.2  rillig 
     36  1.2  rillig 	/* Clang doesn't warn about the 1. */
     37  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     38  1.4  rillig 	bits.minus_1_to_0 = -2;
     39  1.2  rillig 	bits.minus_1_to_0 = -1;
     40  1.2  rillig 	bits.minus_1_to_0 = 0;
     41  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     42  1.4  rillig 	bits.minus_1_to_0 = 1;
     43  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     44  1.4  rillig 	bits.minus_1_to_0 = 2;
     45  1.2  rillig 
     46  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     47  1.4  rillig 	bits.minus_8_to_7 = -9;
     48  1.2  rillig 	bits.minus_8_to_7 = -8;
     49  1.2  rillig 	bits.minus_8_to_7 = 7;
     50  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     51  1.4  rillig 	bits.minus_8_to_7 = 8;
     52  1.2  rillig 
     53  1.2  rillig 	/* Clang doesn't warn about the -1. */
     54  1.4  rillig 	/* expect+1: warning: assignment of negative constant to unsigned type [164] */
     55  1.4  rillig 	bits.zero_to_1 = -2;
     56  1.4  rillig 	/* expect+1: warning: assignment of negative constant to unsigned type [164] */
     57  1.4  rillig 	bits.zero_to_1 = -1;
     58  1.2  rillig 	bits.zero_to_1 = 0;
     59  1.2  rillig 	bits.zero_to_1 = 1;
     60  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     61  1.4  rillig 	bits.zero_to_1 = 2;
     62  1.2  rillig 
     63  1.2  rillig 	/* Clang doesn't warn about the -8. */
     64  1.4  rillig 	/* expect+1: warning: assignment of negative constant to unsigned type [164] */
     65  1.4  rillig 	bits.zero_to_15 = -9;
     66  1.4  rillig 	/* expect+1: warning: assignment of negative constant to unsigned type [164] */
     67  1.4  rillig 	bits.zero_to_15 = -8;
     68  1.2  rillig 	bits.zero_to_15 = 0;
     69  1.2  rillig 	bits.zero_to_15 = 15;
     70  1.4  rillig 	/* expect+1: warning: precision lost in bit-field assignment [166] */
     71  1.4  rillig 	bits.zero_to_15 = 16;
     72  1.2  rillig }
     73