msg_132.c revision 1.21
1 /* $NetBSD: msg_132.c,v 1.21 2022/07/03 14:35:54 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 typedef unsigned char u8_t; 17 typedef unsigned short u16_t; 18 typedef unsigned int u32_t; 19 typedef unsigned long long u64_t; 20 typedef signed char s8_t; 21 typedef signed short s16_t; 22 typedef signed int s32_t; 23 typedef signed long long s64_t; 24 25 u8_t u8; 26 u16_t u16; 27 u32_t u32; 28 u64_t u64; 29 30 s8_t s8; 31 s16_t s16; 32 s32_t s32; 33 s64_t s64; 34 35 void 36 unsigned_to_unsigned(void) 37 { 38 /* expect+1: warning: conversion from 'unsigned short' to 'unsigned char' may lose accuracy [132] */ 39 u8 = u16; 40 /* expect+1: warning: conversion from 'unsigned int' to 'unsigned char' may lose accuracy [132] */ 41 u8 = u32; 42 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned char' may lose accuracy [132] */ 43 u8 = u64; 44 45 u16 = u8; 46 /* expect+1: warning: conversion from 'unsigned int' to 'unsigned short' may lose accuracy [132] */ 47 u16 = u32; 48 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned short' may lose accuracy [132] */ 49 u16 = u64; 50 51 u32 = u8; 52 u32 = u16; 53 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 54 u32 = u64; 55 56 u64 = u8; 57 u64 = u16; 58 u64 = u32; 59 } 60 61 void 62 unsigned_to_signed(void) 63 { 64 /* expect+1: warning: conversion from 'unsigned short' to 'signed char' may lose accuracy [132] */ 65 s8 = u16; 66 /* expect+1: warning: conversion from 'unsigned int' to 'signed char' may lose accuracy [132] */ 67 s8 = u32; 68 /* expect+1: warning: conversion from 'unsigned long long' to 'signed char' may lose accuracy [132] */ 69 s8 = u64; 70 71 s16 = u8; 72 /* expect+1: warning: conversion from 'unsigned int' to 'short' may lose accuracy [132] */ 73 s16 = u32; 74 /* expect+1: warning: conversion from 'unsigned long long' to 'short' may lose accuracy [132] */ 75 s16 = u64; 76 77 s32 = u8; 78 s32 = u16; 79 /* expect+1: warning: conversion from 'unsigned long long' to 'int' may lose accuracy [132] */ 80 s32 = u64; 81 82 s64 = u8; 83 s64 = u16; 84 s64 = u32; 85 } 86 87 void 88 signed_to_unsigned(void) 89 { 90 /* expect+1: warning: conversion from 'short' to 'unsigned char' may lose accuracy [132] */ 91 u8 = s16; 92 /* expect+1: warning: conversion from 'int' to 'unsigned char' may lose accuracy [132] */ 93 u8 = s32; 94 /* expect+1: warning: conversion from 'long long' to 'unsigned char' may lose accuracy [132] */ 95 u8 = s64; 96 97 u16 = s8; 98 /* expect+1: warning: conversion from 'int' to 'unsigned short' may lose accuracy [132] */ 99 u16 = s32; 100 /* expect+1: warning: conversion from 'long long' to 'unsigned short' may lose accuracy [132] */ 101 u16 = s64; 102 103 u32 = s8; 104 u32 = s16; 105 /* expect+1: warning: conversion from 'long long' to 'unsigned int' may lose accuracy [132] */ 106 u32 = s64; 107 108 u64 = s8; 109 u64 = s16; 110 u64 = s32; 111 } 112 113 void 114 signed_to_signed(void) 115 { 116 /* expect+1: warning: conversion from 'short' to 'signed char' may lose accuracy [132] */ 117 s8 = s16; 118 /* expect+1: warning: conversion from 'int' to 'signed char' may lose accuracy [132] */ 119 s8 = s32; 120 /* expect+1: warning: conversion from 'long long' to 'signed char' may lose accuracy [132] */ 121 s8 = s64; 122 123 s16 = s8; 124 /* expect+1: warning: conversion from 'int' to 'short' may lose accuracy [132] */ 125 s16 = s32; 126 /* expect+1: warning: conversion from 'long long' to 'short' may lose accuracy [132] */ 127 s16 = s64; 128 129 s32 = s8; 130 s32 = s16; 131 /* expect+1: warning: conversion from 'long long' to 'int' may lose accuracy [132] */ 132 s32 = s64; 133 134 s64 = s8; 135 s64 = s16; 136 s64 = s32; 137 } 138 139 /* 140 * Before tree.c 1.268 from 2021-04-06, lint wrongly warned that conversion 141 * to _Bool might lose accuracy. C99 6.3.1.2 defines a special conversion 142 * rule from scalar to _Bool though by comparing the value to 0. 143 */ 144 _Bool 145 to_bool(long a, long b) 146 { 147 /* seen in fp_lib.h, function wideRightShiftWithSticky */ 148 return a | b; 149 } 150 151 /* ARGSUSED */ 152 const char * 153 cover_build_plus_minus(const char *arr, double idx) 154 { 155 /* expect+3: error: operands of '+' have incompatible types 'pointer' and 'double' [107] */ 156 /* expect+2: warning: function 'cover_build_plus_minus' expects to return value [214] */ 157 if (idx > 0.0) 158 return arr + idx; 159 return arr + (unsigned int)idx; 160 } 161 162 int 163 non_constant_expression(void) 164 { 165 /* 166 * Even though this variable definition looks like a constant, it 167 * does not fall within C's definition of an integer constant 168 * expression. Due to that, lint does not perform constant folding 169 * on the expression built from this variable and thus doesn't know 170 * that the conversion will always succeed. 171 */ 172 const int not_a_constant = 8; 173 /* expect+1: warning: conversion from 'unsigned long long' to 'int' may lose accuracy [132] */ 174 return not_a_constant * 8ULL; 175 } 176 177 /* 178 * PR 36668 notices that lint wrongly complains about the possible loss. 179 * 180 * The expression 'u8_t << 8' is guaranteed to fit into an 'u16_t', and its 181 * lower 8 bits are guaranteed to be clear. 'u16_t | u8_t' is guaranteed to 182 * fit into 'u16_t'. 183 * 184 * Since tree.c 1.444 from 2022-05-26, lint tracks simple bitwise and 185 * arithmetic constraints across a single expression. 186 */ 187 static inline u16_t 188 be16dec(const void *buf) 189 { 190 const u8_t *p = buf; 191 192 /* 193 * Before tree.c 1.444 from 2022-05-26, lint complained that the 194 * conversion from 'int' to 'unsigned short' may lose accuracy. 195 */ 196 return ((u16_t)p[0]) << 8 | p[1]; 197 } 198 199 /* 200 * Since tree.c 1.434 from 2022-04-19, lint infers the possible values of 201 * expressions of the form 'integer & constant', see can_represent. 202 */ 203 static inline void 204 be32enc(void *buf, u32_t u) 205 { 206 u8_t *p = buf; 207 208 p[0] = u >> 24 & 0xff; 209 p[1] = u >> 16 & 0xff; 210 p[2] = u >> 8 & 0xff; 211 p[3] = u & 0xff; 212 } 213 214 u32_t 215 test_ic_shr(u64_t x) 216 { 217 if (x > 3) 218 return x >> 32; 219 if (x > 2) 220 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 221 return x >> 31; 222 /* expect+1: warning: conversion from 'unsigned long long' to 'unsigned int' may lose accuracy [132] */ 223 return x; 224 } 225 226 227 struct bit_fields { 228 unsigned bits_32: 32; 229 unsigned bits_5: 5; 230 unsigned bits_3: 3; 231 }; 232 233 unsigned char 234 test_bit_fields(struct bit_fields s, unsigned long long m) 235 { 236 /* expect+1: warning: conversion from 'unsigned long long:32' to 'unsigned int:3' may lose accuracy [132] */ 237 s.bits_3 = s.bits_32 & m; 238 239 s.bits_5 = s.bits_3 & m; 240 s.bits_32 = s.bits_5 & m; 241 242 /* expect+1: warning: conversion from 'unsigned long long:32' to 'unsigned char' may lose accuracy [132] */ 243 return s.bits_32 & m; 244 } 245 246 u64_t 247 u64_shl(u64_t lhs, u64_t rhs) 248 { 249 return lhs << rhs; 250 } 251 252 u64_t 253 u64_shr(u64_t lhs, u64_t rhs) 254 { 255 return lhs >> rhs; 256 } 257 258 s64_t 259 s64_shl(s64_t lhs, s64_t rhs) 260 { 261 return lhs << rhs; 262 } 263 264 s64_t 265 s64_shr(s64_t lhs, s64_t rhs) 266 { 267 return lhs >> rhs; 268 } 269
Indexes created Thu Oct 02 14:10:14 GMT 2025