/* $NetBSD: msg_166.c,v 1.6 2024/06/08 06:37:06 rillig Exp $ */
# 3 "msg_166.c"
// Test for message: precision lost in bit-field assignment [166]
/* lint1-extra-flags: -hp -X 351 */
struct bit_set {
/*
* C99 6.7.2p5 and 6.7.2.1p9 footnote 104 say that for bit-fields of
* underlying type 'int', "it is implementation-defined whether the
* specifier 'int' designates the same type as 'signed int' or the
* same type as 'unsigned int'".
*
*
https://gcc.gnu.org/onlinedocs/gcc/Structures-unions-enumerations
* -and-bit-fields-implementation.html says: "By default it is treated
* as 'signed int' but this may be changed by the
* '-funsigned-bitfields' option".
*
* Clang doesn't document implementation-defined behavior, see
*
https://bugs.llvm.org/show_bug.cgi?id=11272.
*/
/* expect+1: warning: bit-field of type plain 'int' has implementation-defined signedness [344] */
int minus_1_to_0: 1;
/* expect+1: warning: bit-field of type plain 'int' has implementation-defined signedness [344] */
int minus_8_to_7: 4;
unsigned zero_to_1: 1;
unsigned zero_to_15: 4;
};
void example(void) {
struct bit_set bits;
/* Clang doesn't warn about the 1. */
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.minus_1_to_0 = -2;
bits.minus_1_to_0 = -1;
bits.minus_1_to_0 = 0;
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.minus_1_to_0 = 1;
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.minus_1_to_0 = 2;
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.minus_8_to_7 = -9;
bits.minus_8_to_7 = -8;
bits.minus_8_to_7 = 7;
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.minus_8_to_7 = 8;
/* Clang doesn't warn about the -1. */
/* expect+1: warning: assignment of negative constant -2 to unsigned type 'unsigned int:1' [164] */
bits.zero_to_1 = -2;
/* expect+1: warning: assignment of negative constant -1 to unsigned type 'unsigned int:1' [164] */
bits.zero_to_1 = -1;
bits.zero_to_1 = 0;
bits.zero_to_1 = 1;
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.zero_to_1 = 2;
/* Clang doesn't warn about the -8. */
/* expect+1: warning: assignment of negative constant -9 to unsigned type 'unsigned int:4' [164] */
bits.zero_to_15 = -9;
/* expect+1: warning: assignment of negative constant -8 to unsigned type 'unsigned int:4' [164] */
bits.zero_to_15 = -8;
bits.zero_to_15 = 0;
bits.zero_to_15 = 15;
/* expect+1: warning: precision lost in bit-field assignment [166] */
bits.zero_to_15 = 16;
}
