1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * Copyright (c) 2014, STMicroelectronics International N.V. 4 */ 5 6 #ifndef COMPILER_H 7 #define COMPILER_H 8 9 /* 10 * Macros that should be used instead of using __attribute__ directly to 11 * ease portability and make the code easier to read. 12 * 13 * Some of the defines below is known to sometimes cause conflicts when 14 * this file is included from xtest in normal world. It is assumed that 15 * the conflicting defines has the same meaning in that environment. 16 * Surrounding the troublesome defines with #ifndef should be enough. 17 */ 18 #define __deprecated __attribute__((deprecated)) 19 #ifndef __packed 20 #define __packed __attribute__((packed)) 21 #endif 22 #define __weak __attribute__((weak)) 23 #define __alias(x) __attribute__((alias(x))) 24 #ifndef __noreturn 25 #define __noreturn __attribute__((__noreturn__)) 26 #endif 27 #ifndef __no_stack_protector 28 #define __no_stack_protector __attribute__((no_stack_protector)) 29 #endif 30 #define __pure __attribute__((pure)) 31 #define __aligned(x) __attribute__((aligned(x))) 32 #define __printf(a, b) __attribute__((format(printf, a, b))) 33 #define __noinline __attribute__((noinline)) 34 #define __attr_const __attribute__((__const__)) 35 #ifndef __unused 36 #define __unused __attribute__((unused)) 37 #endif 38 #define __maybe_unused __attribute__((unused)) 39 #ifndef __used 40 #define __used __attribute__((__used__)) 41 #endif 42 #define __must_check __attribute__((warn_unused_result)) 43 #define __cold __attribute__((__cold__)) 44 #define __section(x) __attribute__((section(x))) 45 #define __data __section(".data") 46 #define __bss __section(".bss") 47 #ifdef __clang__ 48 #define __SECTION_FLAGS_RODATA 49 #else 50 /* 51 * Override sections flags/type generated by the C compiler to make sure they 52 * are: "a",%progbits (thus creating an allocatable, non-writeable, non- 53 * executable data section). 54 * The trailing COMMENT_CHAR comments out the flags generated by the compiler. 55 * This avoids a harmless warning with GCC. 56 */ 57 #if defined(__aarch64__) || defined(__arm__) 58 #define COMMENT_CHAR "//" 59 #else 60 #define COMMENT_CHAR "#" 61 #endif 62 #define __SECTION_FLAGS_RODATA ",\"a\",%progbits " COMMENT_CHAR 63 #endif 64 #define __rodata __section(".rodata" __SECTION_FLAGS_RODATA) 65 #define __rodata_dummy __section(".rodata.dummy" __SECTION_FLAGS_RODATA) 66 #define __rodata_unpaged(x) \ 67 __section(".rodata.__unpaged." x __SECTION_FLAGS_RODATA) 68 #ifdef CFG_CORE_ASLR 69 #define __relrodata_unpaged(x) __section(".data.rel.ro.__unpaged." x) 70 #else 71 #define __relrodata_unpaged(x) __rodata_unpaged(x) 72 #endif 73 #ifdef CFG_NS_VIRTUALIZATION 74 #define __nex_bss __section(".nex_bss") 75 #define __nex_data __section(".nex_data") 76 #else /* CFG_NS_VIRTUALIZATION */ 77 #define __nex_bss 78 #define __nex_data 79 #endif /* CFG_NS_VIRTUALIZATION */ 80 #define __noprof __attribute__((no_instrument_function)) 81 #define __nostackcheck __attribute__((no_instrument_function)) 82 83 #define __compiler_bswap64(x) __builtin_bswap64((x)) 84 #define __compiler_bswap32(x) __builtin_bswap32((x)) 85 #define __compiler_bswap16(x) __builtin_bswap16((x)) 86 87 #define __GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \ 88 __GNUC_PATCHLEVEL__) 89 90 #if __GCC_VERSION >= 50100 && !defined(__CHECKER__) 91 #define __HAVE_BUILTIN_OVERFLOW 1 92 #endif 93 94 #if __GCC_VERSION >= 90100 && !defined(__CHECKER__) 95 #define __HAVE_SINGLE_ARGUMENT_STATIC_ASSERT 1 96 #endif 97 98 #ifdef __HAVE_BUILTIN_OVERFLOW 99 #define __compiler_add_overflow(a, b, res) \ 100 __builtin_add_overflow((a), (b), (res)) 101 102 #define __compiler_sub_overflow(a, b, res) \ 103 __builtin_sub_overflow((a), (b), (res)) 104 105 #define __compiler_mul_overflow(a, b, res) \ 106 __builtin_mul_overflow((a), (b), (res)) 107 #else /*!__HAVE_BUILTIN_OVERFLOW*/ 108 109 /* 110 * Copied/inspired from https://www.fefe.de/intof.html 111 */ 112 113 #define __INTOF_ASSIGN(dest, src) (__extension__({ \ 114 typeof(src) __intof_x = (src); \ 115 typeof(dest) __intof_y = __intof_x; \ 116 (((uintmax_t)__intof_x == (uintmax_t)__intof_y) && \ 117 ((__intof_x < 1) == (__intof_y < 1)) ? \ 118 (void)((dest) = __intof_y) , 0 : 1); \ 119 })) 120 121 #define __INTOF_ADD(c, a, b) (__extension__({ \ 122 typeof(a) __intofa_a = (a); \ 123 typeof(b) __intofa_b = (b); \ 124 intmax_t __intofa_a_signed = __intofa_a; \ 125 uintmax_t __intofa_a_unsigned = __intofa_a; \ 126 intmax_t __intofa_b_signed = __intofa_b; \ 127 uintmax_t __intofa_b_unsigned = __intofa_b; \ 128 \ 129 __intofa_b < 1 ? \ 130 __intofa_a < 1 ? \ 131 ((INTMAX_MIN - __intofa_b_signed <= \ 132 __intofa_a_signed)) ? \ 133 __INTOF_ASSIGN((c), __intofa_a_signed + \ 134 __intofa_b_signed) : 1 \ 135 : \ 136 ((__intofa_a_unsigned >= (uintmax_t)-__intofa_b) ? \ 137 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 138 __intofa_b_signed) \ 139 : \ 140 __INTOF_ASSIGN((c), \ 141 (intmax_t)(__intofa_a_unsigned + \ 142 __intofa_b_signed))) \ 143 : \ 144 __intofa_a < 1 ? \ 145 ((__intofa_b_unsigned >= (uintmax_t)-__intofa_a) ? \ 146 __INTOF_ASSIGN((c), __intofa_a_signed + \ 147 __intofa_b_unsigned) \ 148 : \ 149 __INTOF_ASSIGN((c), \ 150 (intmax_t)(__intofa_a_signed + \ 151 __intofa_b_unsigned))) \ 152 : \ 153 ((UINTMAX_MAX - __intofa_b_unsigned >= \ 154 __intofa_a_unsigned) ? \ 155 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 156 __intofa_b_unsigned) : 1); \ 157 })) 158 159 #define __INTOF_SUB(c, a, b) (__extension__({ \ 160 typeof(a) __intofs_a = a; \ 161 typeof(b) __intofs_b = b; \ 162 intmax_t __intofs_a_signed = __intofs_a; \ 163 uintmax_t __intofs_a_unsigned = __intofs_a; \ 164 intmax_t __intofs_b_signed = __intofs_b; \ 165 uintmax_t __intofs_b_unsigned = __intofs_b; \ 166 \ 167 __intofs_b < 1 ? \ 168 __intofs_a < 1 ? \ 169 ((INTMAX_MAX + __intofs_b_signed >= \ 170 __intofs_a_signed) ? \ 171 __INTOF_ASSIGN((c), __intofs_a_signed - \ 172 __intofs_b_signed) : 1) \ 173 : \ 174 (((uintmax_t)(UINTMAX_MAX + __intofs_b_signed) >= \ 175 __intofs_a_unsigned) ? \ 176 __INTOF_ASSIGN((c), __intofs_a - \ 177 __intofs_b) : 1) \ 178 : \ 179 __intofs_a < 1 ? \ 180 (((intmax_t)(INTMAX_MIN + __intofs_b) <= \ 181 __intofs_a_signed) ? \ 182 __INTOF_ASSIGN((c), \ 183 (intmax_t)(__intofs_a_signed - \ 184 __intofs_b_unsigned)) : 1) \ 185 : \ 186 ((__intofs_b_unsigned <= __intofs_a_unsigned) ? \ 187 __INTOF_ASSIGN((c), __intofs_a_unsigned - \ 188 __intofs_b_unsigned) \ 189 : \ 190 __INTOF_ASSIGN((c), \ 191 (intmax_t)(__intofs_a_unsigned - \ 192 __intofs_b_unsigned))); \ 193 })) 194 195 /* 196 * Dealing with detecting overflow in multiplication of integers. 197 * 198 * First step is to remove two corner cases with the minum signed integer 199 * which can't be represented as a positive integer + sign. 200 * Multiply with 0 or 1 can't overflow, no checking needed of the operation, 201 * only if it can be assigned to the result. 202 * 203 * After the corner cases are eliminated we convert the two factors to 204 * positive unsigned values, keeping track of the original in another 205 * variable which is used at the end to determine the sign of the product. 206 * 207 * The two terms (a and b) are divided into upper and lower half (x1 upper 208 * and x0 lower), so the product is: 209 * ((a1 << hshift) + a0) * ((b1 << hshift) + b0) 210 * which also is: 211 * ((a1 * b1) << (hshift * 2)) + (T1) 212 * ((a1 * b0 + a0 * b1) << hshift) + (T2) 213 * (a0 * b0) (T3) 214 * 215 * From this we can tell and (a1 * b1) has to be 0 or we'll overflow, that 216 * is, at least one of a1 or b1 has to be 0. Once this has been checked the 217 * addition: ((a1 * b0) << hshift) + ((a0 * b1) << hshift) 218 * isn't an addition as one of the terms will be 0. 219 * 220 * Since each factor in: (a0 * b0) 221 * only uses half the capicity of the underlaying type it can't overflow 222 * 223 * The addition of T2 and T3 can overflow so we use __INTOF_ADD() to 224 * perform that addition. If the addition succeeds without overflow the 225 * result is assigned the required sign and checked for overflow again. 226 */ 227 228 #define __intof_mul_negate ((__intof_oa < 1) != (__intof_ob < 1)) 229 #define __intof_mul_hshift (sizeof(uintmax_t) * 8 / 2) 230 #define __intof_mul_hmask (UINTMAX_MAX >> __intof_mul_hshift) 231 #define __intof_mul_a0 ((uintmax_t)(__intof_a) >> __intof_mul_hshift) 232 #define __intof_mul_b0 ((uintmax_t)(__intof_b) >> __intof_mul_hshift) 233 #define __intof_mul_a1 ((uintmax_t)(__intof_a) & __intof_mul_hmask) 234 #define __intof_mul_b1 ((uintmax_t)(__intof_b) & __intof_mul_hmask) 235 #define __intof_mul_t (__intof_mul_a1 * __intof_mul_b0 + \ 236 __intof_mul_a0 * __intof_mul_b1) 237 238 #define __INTOF_MUL(c, a, b) (__extension__({ \ 239 typeof(a) __intof_oa = (a); \ 240 typeof(a) __intof_a = __intof_oa < 1 ? -__intof_oa : __intof_oa; \ 241 typeof(b) __intof_ob = (b); \ 242 typeof(b) __intof_b = __intof_ob < 1 ? -__intof_ob : __intof_ob; \ 243 typeof(c) __intof_c; \ 244 \ 245 __intof_oa == 0 || __intof_ob == 0 || \ 246 __intof_oa == 1 || __intof_ob == 1 ? \ 247 __INTOF_ASSIGN((c), __intof_oa * __intof_ob) : \ 248 (__intof_mul_a0 && __intof_mul_b0) || \ 249 __intof_mul_t > __intof_mul_hmask ? 1 : \ 250 __INTOF_ADD((__intof_c), __intof_mul_t << __intof_mul_hshift, \ 251 __intof_mul_a1 * __intof_mul_b1) ? 1 : \ 252 __intof_mul_negate ? __INTOF_ASSIGN((c), -__intof_c) : \ 253 __INTOF_ASSIGN((c), __intof_c); \ 254 })) 255 256 #define __compiler_add_overflow(a, b, res) __INTOF_ADD(*(res), (a), (b)) 257 #define __compiler_sub_overflow(a, b, res) __INTOF_SUB(*(res), (a), (b)) 258 #define __compiler_mul_overflow(a, b, res) __INTOF_MUL(*(res), (a), (b)) 259 260 #endif /*!__HAVE_BUILTIN_OVERFLOW*/ 261 262 #define __compiler_compare_and_swap(p, oval, nval) \ 263 __atomic_compare_exchange_n((p), (oval), (nval), true, \ 264 __ATOMIC_ACQUIRE, __ATOMIC_RELAXED) \ 265 266 #define __compiler_atomic_load(p) __atomic_load_n((p), __ATOMIC_RELAXED) 267 #define __compiler_atomic_store(p, val) \ 268 __atomic_store_n((p), (val), __ATOMIC_RELAXED) 269 270 #define barrier() asm volatile ("" : : : "memory") 271 272 #ifndef __has_attribute 273 #define __has_attribute(x) 0 274 #endif 275 276 #if __has_attribute(__fallthrough__) 277 #define fallthrough __attribute__((__fallthrough__)) 278 #else 279 #define fallthrough do {} while (0) /* fallthrough */ 280 #endif 281 282 #ifndef __clang__ 283 #define __no_stackprot __attribute__((__optimize__ ("-fno-stack-protector"))) 284 #else 285 #define __no_stackprot 286 #endif 287 288 #define __inhibit_loop_to_libcall \ 289 __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns"))) 290 #endif /*COMPILER_H*/ 291