1 /* 2 ** $Id: llimits.h $ 3 ** Limits, basic types, and some other 'installation-dependent' definitions 4 ** See Copyright Notice in lua.h 5 */ 6 7 #ifndef llimits_h 8 #define llimits_h 9 10 11 #include <limits.h> 12 #include <stddef.h> 13 14 15 #include "lua.h" 16 17 18 /* 19 ** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count 20 ** the total memory used by Lua (in bytes). Usually, 'size_t' and 21 ** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines. 22 */ 23 #if defined(LUAI_MEM) /* { external definitions? */ 24 typedef LUAI_UMEM lu_mem; 25 typedef LUAI_MEM l_mem; 26 #elif LUAI_IS32INT /* }{ */ 27 typedef size_t lu_mem; 28 typedef ptrdiff_t l_mem; 29 #else /* 16-bit ints */ /* }{ */ 30 typedef unsigned long lu_mem; 31 typedef long l_mem; 32 #endif /* } */ 33 34 35 /* chars used as small naturals (so that 'char' is reserved for characters) */ 36 typedef unsigned char lu_byte; 37 typedef signed char ls_byte; 38 39 40 /* maximum value for size_t */ 41 #define MAX_SIZET ((size_t)(~(size_t)0)) 42 43 /* maximum size visible for Lua (must be representable in a lua_Integer) */ 44 #define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ 45 : (size_t)(LUA_MAXINTEGER)) 46 47 48 #define MAX_LUMEM ((lu_mem)(~(lu_mem)0)) 49 50 #define MAX_LMEM ((l_mem)(MAX_LUMEM >> 1)) 51 52 53 #define MAX_INT INT_MAX /* maximum value of an int */ 54 55 56 /* 57 ** floor of the log2 of the maximum signed value for integral type 't'. 58 ** (That is, maximum 'n' such that '2^n' fits in the given signed type.) 59 */ 60 #define log2maxs(t) (sizeof(t) * 8 - 2) 61 62 63 /* 64 ** test whether an unsigned value is a power of 2 (or zero) 65 */ 66 #define ispow2(x) (((x) & ((x) - 1)) == 0) 67 68 69 /* number of chars of a literal string without the ending \0 */ 70 #define LL(x) (sizeof(x)/sizeof(char) - 1) 71 72 73 /* 74 ** conversion of pointer to unsigned integer: this is for hashing only; 75 ** there is no problem if the integer cannot hold the whole pointer 76 ** value. (In strict ISO C this may cause undefined behavior, but no 77 ** actual machine seems to bother.) 78 */ 79 #if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \ 80 __STDC_VERSION__ >= 199901L 81 #include <stdint.h> 82 #if defined(UINTPTR_MAX) /* even in C99 this type is optional */ 83 #define L_P2I uintptr_t 84 #else /* no 'intptr'? */ 85 #define L_P2I uintmax_t /* use the largest available integer */ 86 #endif 87 #else /* C89 option */ 88 #define L_P2I size_t 89 #endif 90 91 #define point2uint(p) ((unsigned int)((L_P2I)(p) & UINT_MAX)) 92 93 94 95 /* types of 'usual argument conversions' for lua_Number and lua_Integer */ 96 typedef LUAI_UACNUMBER l_uacNumber; 97 typedef LUAI_UACINT l_uacInt; 98 99 100 /* 101 ** Internal assertions for in-house debugging 102 */ 103 #if defined LUAI_ASSERT 104 #undef NDEBUG 105 #include <assert.h> 106 #define lua_assert(c) assert(c) 107 #endif 108 109 #if defined(lua_assert) 110 #define check_exp(c,e) (lua_assert(c), (e)) 111 /* to avoid problems with conditions too long */ 112 #define lua_longassert(c) ((c) ? (void)0 : lua_assert(0)) 113 #else 114 #define lua_assert(c) ((void)0) 115 #define check_exp(c,e) (e) 116 #define lua_longassert(c) ((void)0) 117 #endif 118 119 /* 120 ** assertion for checking API calls 121 */ 122 #if !defined(luai_apicheck) 123 #define luai_apicheck(l,e) ((void)l, lua_assert(e)) 124 #endif 125 126 #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) 127 128 129 /* macro to avoid warnings about unused variables */ 130 #if !defined(UNUSED) 131 #define UNUSED(x) ((void)(x)) 132 #endif 133 134 135 /* type casts (a macro highlights casts in the code) */ 136 #define cast(t, exp) ((t)(exp)) 137 138 #define cast_void(i) cast(void, (i)) 139 #define cast_voidp(i) cast(void *, (i)) 140 #define cast_num(i) cast(lua_Number, (i)) 141 #define cast_int(i) cast(int, (i)) 142 #define cast_uint(i) cast(unsigned int, (i)) 143 #define cast_byte(i) cast(lu_byte, (i)) 144 #define cast_uchar(i) cast(unsigned char, (i)) 145 #define cast_char(i) cast(char, (i)) 146 #define cast_charp(i) cast(char *, (i)) 147 #define cast_sizet(i) cast(size_t, (i)) 148 149 150 /* cast a signed lua_Integer to lua_Unsigned */ 151 #if !defined(l_castS2U) 152 #define l_castS2U(i) ((lua_Unsigned)(i)) 153 #endif 154 155 /* 156 ** cast a lua_Unsigned to a signed lua_Integer; this cast is 157 ** not strict ISO C, but two-complement architectures should 158 ** work fine. 159 */ 160 #if !defined(l_castU2S) 161 #define l_castU2S(i) ((lua_Integer)(i)) 162 #endif 163 164 165 /* 166 ** non-return type 167 */ 168 #if !defined(l_noret) 169 170 #if defined(__GNUC__) 171 #define l_noret void __attribute__((noreturn)) 172 #elif defined(_MSC_VER) && _MSC_VER >= 1200 173 #define l_noret void __declspec(noreturn) 174 #else 175 #define l_noret void 176 #endif 177 178 #endif 179 180 181 /* 182 ** Inline functions 183 */ 184 #if !defined(LUA_USE_C89) 185 #define l_inline inline 186 #elif defined(__GNUC__) 187 #define l_inline __inline__ 188 #else 189 #define l_inline /* empty */ 190 #endif 191 192 #define l_sinline static l_inline 193 194 195 /* 196 ** type for virtual-machine instructions; 197 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) 198 */ 199 #if LUAI_IS32INT 200 typedef unsigned int l_uint32; 201 #else 202 typedef unsigned long l_uint32; 203 #endif 204 205 typedef l_uint32 Instruction; 206 207 208 209 /* 210 ** Maximum length for short strings, that is, strings that are 211 ** internalized. (Cannot be smaller than reserved words or tags for 212 ** metamethods, as these strings must be internalized; 213 ** #("function") = 8, #("__newindex") = 10.) 214 */ 215 #if !defined(LUAI_MAXSHORTLEN) 216 #define LUAI_MAXSHORTLEN 40 217 #endif 218 219 220 /* 221 ** Initial size for the string table (must be power of 2). 222 ** The Lua core alone registers ~50 strings (reserved words + 223 ** metaevent keys + a few others). Libraries would typically add 224 ** a few dozens more. 225 */ 226 #if !defined(MINSTRTABSIZE) 227 #define MINSTRTABSIZE 128 228 #endif 229 230 231 /* 232 ** Size of cache for strings in the API. 'N' is the number of 233 ** sets (better be a prime) and "M" is the size of each set (M == 1 234 ** makes a direct cache.) 235 */ 236 #if !defined(STRCACHE_N) 237 #define STRCACHE_N 53 238 #define STRCACHE_M 2 239 #endif 240 241 242 /* minimum size for string buffer */ 243 #if !defined(LUA_MINBUFFER) 244 #define LUA_MINBUFFER 32 245 #endif 246 247 248 /* 249 ** Maximum depth for nested C calls, syntactical nested non-terminals, 250 ** and other features implemented through recursion in C. (Value must 251 ** fit in a 16-bit unsigned integer. It must also be compatible with 252 ** the size of the C stack.) 253 */ 254 #if !defined(LUAI_MAXCCALLS) 255 #define LUAI_MAXCCALLS 200 256 #endif 257 258 259 /* 260 ** macros that are executed whenever program enters the Lua core 261 ** ('lua_lock') and leaves the core ('lua_unlock') 262 */ 263 #if !defined(lua_lock) 264 #define lua_lock(L) ((void) 0) 265 #define lua_unlock(L) ((void) 0) 266 #endif 267 268 /* 269 ** macro executed during Lua functions at points where the 270 ** function can yield. 271 */ 272 #if !defined(luai_threadyield) 273 #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} 274 #endif 275 276 277 /* 278 ** these macros allow user-specific actions when a thread is 279 ** created/deleted/resumed/yielded. 280 */ 281 #if !defined(luai_userstateopen) 282 #define luai_userstateopen(L) ((void)L) 283 #endif 284 285 #if !defined(luai_userstateclose) 286 #define luai_userstateclose(L) ((void)L) 287 #endif 288 289 #if !defined(luai_userstatethread) 290 #define luai_userstatethread(L,L1) ((void)L) 291 #endif 292 293 #if !defined(luai_userstatefree) 294 #define luai_userstatefree(L,L1) ((void)L) 295 #endif 296 297 #if !defined(luai_userstateresume) 298 #define luai_userstateresume(L,n) ((void)L) 299 #endif 300 301 #if !defined(luai_userstateyield) 302 #define luai_userstateyield(L,n) ((void)L) 303 #endif 304 305 306 307 /* 308 ** The luai_num* macros define the primitive operations over numbers. 309 */ 310 311 /* floor division (defined as 'floor(a/b)') */ 312 #if !defined(luai_numidiv) 313 #define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) 314 #endif 315 316 /* float division */ 317 #if !defined(luai_numdiv) 318 #define luai_numdiv(L,a,b) ((a)/(b)) 319 #endif 320 321 /* 322 ** modulo: defined as 'a - floor(a/b)*b'; the direct computation 323 ** using this definition has several problems with rounding errors, 324 ** so it is better to use 'fmod'. 'fmod' gives the result of 325 ** 'a - trunc(a/b)*b', and therefore must be corrected when 326 ** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a 327 ** non-integer negative result: non-integer result is equivalent to 328 ** a non-zero remainder 'm'; negative result is equivalent to 'a' and 329 ** 'b' with different signs, or 'm' and 'b' with different signs 330 ** (as the result 'm' of 'fmod' has the same sign of 'a'). 331 */ 332 #if !defined(luai_nummod) 333 #define luai_nummod(L,a,b,m) \ 334 { (void)L; (m) = l_mathop(fmod)(a,b); \ 335 if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); } 336 #endif 337 338 /* exponentiation */ 339 #if !defined(luai_numpow) 340 #define luai_numpow(L,a,b) \ 341 ((void)L, (b == 2) ? (a)*(a) : l_mathop(pow)(a,b)) 342 #endif 343 344 /* the others are quite standard operations */ 345 #if !defined(luai_numadd) 346 #define luai_numadd(L,a,b) ((a)+(b)) 347 #define luai_numsub(L,a,b) ((a)-(b)) 348 #define luai_nummul(L,a,b) ((a)*(b)) 349 #define luai_numunm(L,a) (-(a)) 350 #define luai_numeq(a,b) ((a)==(b)) 351 #define luai_numlt(a,b) ((a)<(b)) 352 #define luai_numle(a,b) ((a)<=(b)) 353 #define luai_numgt(a,b) ((a)>(b)) 354 #define luai_numge(a,b) ((a)>=(b)) 355 #define luai_numisnan(a) (!luai_numeq((a), (a))) 356 #endif 357 358 359 360 361 362 /* 363 ** macro to control inclusion of some hard tests on stack reallocation 364 */ 365 #if !defined(HARDSTACKTESTS) 366 #define condmovestack(L,pre,pos) ((void)0) 367 #else 368 /* realloc stack keeping its size */ 369 #define condmovestack(L,pre,pos) \ 370 { int sz_ = stacksize(L); pre; luaD_reallocstack((L), sz_, 0); pos; } 371 #endif 372 373 #if !defined(HARDMEMTESTS) 374 #define condchangemem(L,pre,pos) ((void)0) 375 #else 376 #define condchangemem(L,pre,pos) \ 377 { if (gcrunning(G(L))) { pre; luaC_fullgc(L, 0); pos; } } 378 #endif 379 380 #endif 381