msg_132.c revision 1.19
1 /* $NetBSD: msg_132.c,v 1.19 2022/06/19 12:14:34 rillig Exp $ */ 2 # 3 "msg_132.c" 3 4 // Test for message: conversion from '%s' to '%s' may lose accuracy [132] 5 6 /* 7 * NetBSD's default lint flags only include a single -a, which only flags 8 * narrowing conversions from long. To get warnings for all narrowing 9 * conversions, -a needs to be given more than once. 10 * 11 * https://gnats.netbsd.org/14531 12 */ 13 14 /* lint1-extra-flags: -aa */ 15 16 unsigned char u8; 17 unsigned short u16; 18 unsigned int u32; 19 unsigned long long u64; 20 21 signed char s8; 22 signed short s16; 23 signed int s32; 24 signed long long s64; 25 26 void 27 unsigned_to_unsigned(void) 28 { 29 /* expect+1: warning: conversion from 'unsigned short' to 'unsigned char' may lose accuracy [132] */ 30 u8 = u16; 31 /* expect+1: warning: conversion from 'unsigned int' to 'unsigned char' may lose accuracy [132] */ 32 u8 = u32; 33 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned char' may lose accuracy [132] */ 34 u8 = u64; 35 36 u16 = u8; 37 /* expect+1: warning: conversion from 'unsigned int' to 'unsigned short' may lose accuracy [132] */ 38 u16 = u32; 39 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned short' may lose accuracy [132] */ 40 u16 = u64; 41 42 u32 = u8; 43 u32 = u16; 44 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 45 u32 = u64; 46 47 u64 = u8; 48 u64 = u16; 49 u64 = u32; 50 } 51 52 void 53 unsigned_to_signed(void) 54 { 55 /* expect+1: warning: conversion from 'unsigned short' to 'signed char' may lose accuracy [132] */ 56 s8 = u16; 57 /* expect+1: warning: conversion from 'unsigned int' to 'signed char' may lose accuracy [132] */ 58 s8 = u32; 59 /* expect+1: warning: conversion from 'unsigned long long' to 'signed char' may lose accuracy [132] */ 60 s8 = u64; 61 62 s16 = u8; 63 /* expect+1: warning: conversion from 'unsigned int' to 'short' may lose accuracy [132] */ 64 s16 = u32; 65 /* expect+1: warning: conversion from 'unsigned long long' to 'short' may lose accuracy [132] */ 66 s16 = u64; 67 68 s32 = u8; 69 s32 = u16; 70 /* expect+1: warning: conversion from 'unsigned long long' to 'int' may lose accuracy [132] */ 71 s32 = u64; 72 73 s64 = u8; 74 s64 = u16; 75 s64 = u32; 76 } 77 78 void 79 signed_to_unsigned(void) 80 { 81 /* expect+1: warning: conversion from 'short' to 'unsigned char' may lose accuracy [132] */ 82 u8 = s16; 83 /* expect+1: warning: conversion from 'int' to 'unsigned char' may lose accuracy [132] */ 84 u8 = s32; 85 /* expect+1: warning: conversion from 'long long' to 'unsigned char' may lose accuracy [132] */ 86 u8 = s64; 87 88 u16 = s8; 89 /* expect+1: warning: conversion from 'int' to 'unsigned short' may lose accuracy [132] */ 90 u16 = s32; 91 /* expect+1: warning: conversion from 'long long' to 'unsigned short' may lose accuracy [132] */ 92 u16 = s64; 93 94 u32 = s8; 95 u32 = s16; 96 /* expect+1: warning: conversion from 'long long' to 'unsigned int' may lose accuracy [132] */ 97 u32 = s64; 98 99 u64 = s8; 100 u64 = s16; 101 u64 = s32; 102 } 103 104 void 105 signed_to_signed(void) 106 { 107 /* expect+1: warning: conversion from 'short' to 'signed char' may lose accuracy [132] */ 108 s8 = s16; 109 /* expect+1: warning: conversion from 'int' to 'signed char' may lose accuracy [132] */ 110 s8 = s32; 111 /* expect+1: warning: conversion from 'long long' to 'signed char' may lose accuracy [132] */ 112 s8 = s64; 113 114 s16 = s8; 115 /* expect+1: warning: conversion from 'int' to 'short' may lose accuracy [132] */ 116 s16 = s32; 117 /* expect+1: warning: conversion from 'long long' to 'short' may lose accuracy [132] */ 118 s16 = s64; 119 120 s32 = s8; 121 s32 = s16; 122 /* expect+1: warning: conversion from 'long long' to 'int' may lose accuracy [132] */ 123 s32 = s64; 124 125 s64 = s8; 126 s64 = s16; 127 s64 = s32; 128 } 129 130 /* 131 * Before tree.c 1.268 from 2021-04-06, lint wrongly warned that conversion 132 * to _Bool might lose accuracy. C99 6.3.1.2 defines a special conversion 133 * rule from scalar to _Bool though by comparing the value to 0. 134 */ 135 _Bool 136 to_bool(long a, long b) 137 { 138 /* seen in fp_lib.h, function wideRightShiftWithSticky */ 139 return a | b; 140 } 141 142 /* ARGSUSED */ 143 const char * 144 cover_build_plus_minus(const char *arr, double idx) 145 { 146 /* expect+3: error: operands of '+' have incompatible types 'pointer' and 'double' [107] */ 147 /* expect+2: warning: function 'cover_build_plus_minus' expects to return value [214] */ 148 if (idx > 0.0) 149 return arr + idx; 150 return arr + (unsigned int)idx; 151 } 152 153 int 154 non_constant_expression(void) 155 { 156 /* 157 * Even though this variable definition looks like a constant, it 158 * does not fall within C's definition of an integer constant 159 * expression. Due to that, lint does not perform constant folding 160 * on the expression built from this variable and thus doesn't know 161 * that the conversion will always succeed. 162 */ 163 const int not_a_constant = 8; 164 /* expect+1: warning: conversion from 'unsigned long long' to 'int' may lose accuracy [132] */ 165 return not_a_constant * 8ULL; 166 } 167 168 typedef unsigned char u8_t; 169 typedef unsigned short u16_t; 170 typedef unsigned int u32_t; 171 typedef unsigned long long u64_t; 172 173 /* 174 * PR 36668 notices that lint wrongly complains about the possible loss. 175 * 176 * The expression 'u8_t << 8' is guaranteed to fit into an 'u16_t', and its 177 * lower 8 bits are guaranteed to be clear. 'u16_t | u8_t' is guaranteed to 178 * fit into 'u16_t'. 179 * 180 * Since tree.c 1.444 from 2022-05-26, lint tracks simple bitwise and 181 * arithmetic constraints across a single expression. 182 */ 183 static inline u16_t 184 be16dec(const void *buf) 185 { 186 const u8_t *p = buf; 187 188 /* 189 * Before tree.c 1.444 from 2022-05-26, lint complained that the 190 * conversion from 'int' to 'unsigned short' may lose accuracy. 191 */ 192 return ((u16_t)p[0]) << 8 | p[1]; 193 } 194 195 /* 196 * Since tree.c 1.434 from 2022-04-19, lint infers the possible values of 197 * expressions of the form 'integer & constant', see can_represent. 198 */ 199 static inline void 200 be32enc(void *buf, u32_t u) 201 { 202 u8_t *p = buf; 203 204 p[0] = u >> 24 & 0xff; 205 p[1] = u >> 16 & 0xff; 206 p[2] = u >> 8 & 0xff; 207 p[3] = u & 0xff; 208 } 209 210 u32_t 211 test_ic_shr(u64_t x) 212 { 213 if (x > 3) 214 return x >> 32; 215 if (x > 2) 216 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 217 return x >> 31; 218 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 219 return x; 220 } 221 222 223 struct bit_fields { 224 unsigned bits_32: 32; 225 unsigned bits_5: 5; 226 unsigned bits_3: 3; 227 }; 228 229 unsigned char 230 test_bit_fields(struct bit_fields s, unsigned long long m) 231 { 232 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 233 s.bits_3 = s.bits_32 & m; 234 235 s.bits_5 = s.bits_3 & m; 236 s.bits_32 = s.bits_5 & m; 237 238 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned char' may lose accuracy [132] */ 239 return s.bits_32 & m; 240 } 241
Indexes created Thu Oct 02 14:10:14 GMT 2025