1 /* 2 ** $Id: llimits.h,v 1.141.1.1 2017/04/19 17:20:42 roberto Exp $ 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 ** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count 19 ** the total memory used by Lua (in bytes). Usually, 'size_t' and 20 ** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines. 21 */ 22 #if defined(LUAI_MEM) /* { external definitions? */ 23 typedef LUAI_UMEM lu_mem; 24 typedef LUAI_MEM l_mem; 25 #elif LUAI_BITSINT >= 32 /* }{ */ 26 typedef size_t lu_mem; 27 typedef ptrdiff_t l_mem; 28 #else /* 16-bit ints */ /* }{ */ 29 typedef unsigned long lu_mem; 30 typedef long l_mem; 31 #endif /* } */ 32 33 34 /* chars used as small naturals (so that 'char' is reserved for characters) */ 35 typedef unsigned char lu_byte; 36 37 38 /* maximum value for size_t */ 39 #define MAX_SIZET ((size_t)(~(size_t)0)) 40 41 /* maximum size visible for Lua (must be representable in a lua_Integer */ 42 #define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ 43 : (size_t)(LUA_MAXINTEGER)) 44 45 46 #define MAX_LUMEM ((lu_mem)(~(lu_mem)0)) 47 48 #define MAX_LMEM ((l_mem)(MAX_LUMEM >> 1)) 49 50 51 #define MAX_INT INT_MAX /* maximum value of an int */ 52 53 54 /* 55 ** conversion of pointer to unsigned integer: 56 ** this is for hashing only; there is no problem if the integer 57 ** cannot hold the whole pointer value 58 */ 59 #define point2uint(p) ((unsigned int)((size_t)(p) & UINT_MAX)) 60 61 62 63 /* type to ensure maximum alignment */ 64 #if defined(LUAI_USER_ALIGNMENT_T) 65 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign; 66 #else 67 typedef union { 68 lua_Number n; 69 #if LUA_FLOAT_TYPE != LUA_FLOAT_INT64 70 double u; 71 #endif 72 void *s; 73 lua_Integer i; 74 long l; 75 } L_Umaxalign; 76 #endif 77 78 79 80 /* types of 'usual argument conversions' for lua_Number and lua_Integer */ 81 typedef LUAI_UACNUMBER l_uacNumber; 82 typedef LUAI_UACINT l_uacInt; 83 84 85 /* internal assertions for in-house debugging */ 86 #if defined(lua_assert) 87 #define check_exp(c,e) (lua_assert(c), (e)) 88 /* to avoid problems with conditions too long */ 89 #define lua_longassert(c) ((c) ? (void)0 : lua_assert(0)) 90 #else 91 #define lua_assert(c) ((void)0) 92 #define check_exp(c,e) (e) 93 #define lua_longassert(c) ((void)0) 94 #endif 95 96 /* 97 ** assertion for checking API calls 98 */ 99 #if !defined(luai_apicheck) 100 #define luai_apicheck(l,e) lua_assert(e) 101 #endif 102 103 #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) 104 105 106 /* macro to avoid warnings about unused variables */ 107 #if !defined(UNUSED) 108 #define UNUSED(x) ((void)(x)) 109 #endif 110 111 112 /* type casts (a macro highlights casts in the code) */ 113 #define cast(t, exp) ((t)(exp)) 114 115 #define cast_void(i) cast(void, (i)) 116 #define cast_byte(i) cast(lu_byte, (i)) 117 #define cast_num(i) cast(lua_Number, (i)) 118 #define cast_int(i) cast(int, (i)) 119 #define cast_uchar(i) cast(unsigned char, (i)) 120 121 122 /* cast a signed lua_Integer to lua_Unsigned */ 123 #if !defined(l_castS2U) 124 #define l_castS2U(i) ((lua_Unsigned)(i)) 125 #endif 126 127 /* 128 ** cast a lua_Unsigned to a signed lua_Integer; this cast is 129 ** not strict ISO C, but two-complement architectures should 130 ** work fine. 131 */ 132 #if !defined(l_castU2S) 133 #define l_castU2S(i) ((lua_Integer)(i)) 134 #endif 135 136 137 /* 138 ** non-return type 139 */ 140 #if defined(__GNUC__) 141 #define l_noret void __attribute__((noreturn)) 142 #elif defined(_MSC_VER) && _MSC_VER >= 1200 143 #define l_noret void __declspec(noreturn) 144 #else 145 #define l_noret void 146 #endif 147 148 149 150 /* 151 ** maximum depth for nested C calls and syntactical nested non-terminals 152 ** in a program. (Value must fit in an unsigned short int.) 153 */ 154 #if !defined(LUAI_MAXCCALLS) 155 #define LUAI_MAXCCALLS 200 156 #endif 157 158 159 160 /* 161 ** type for virtual-machine instructions; 162 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) 163 */ 164 #if LUAI_BITSINT >= 32 165 typedef unsigned int Instruction; 166 #else 167 typedef unsigned long Instruction; 168 #endif 169 170 171 172 /* 173 ** Maximum length for short strings, that is, strings that are 174 ** internalized. (Cannot be smaller than reserved words or tags for 175 ** metamethods, as these strings must be internalized; 176 ** #("function") = 8, #("__newindex") = 10.) 177 */ 178 #if !defined(LUAI_MAXSHORTLEN) 179 #define LUAI_MAXSHORTLEN 40 180 #endif 181 182 183 /* 184 ** Initial size for the string table (must be power of 2). 185 ** The Lua core alone registers ~50 strings (reserved words + 186 ** metaevent keys + a few others). Libraries would typically add 187 ** a few dozens more. 188 */ 189 #if !defined(MINSTRTABSIZE) 190 #define MINSTRTABSIZE 128 191 #endif 192 193 194 /* 195 ** Size of cache for strings in the API. 'N' is the number of 196 ** sets (better be a prime) and "M" is the size of each set (M == 1 197 ** makes a direct cache.) 198 */ 199 #if !defined(STRCACHE_N) 200 #define STRCACHE_N 53 201 #define STRCACHE_M 2 202 #endif 203 204 205 /* minimum size for string buffer */ 206 #if !defined(LUA_MINBUFFER) 207 #define LUA_MINBUFFER 32 208 #endif 209 210 211 /* 212 ** macros that are executed whenever program enters the Lua core 213 ** ('lua_lock') and leaves the core ('lua_unlock') 214 */ 215 #if !defined(lua_lock) 216 #define lua_lock(L) ((void) 0) 217 #define lua_unlock(L) ((void) 0) 218 #endif 219 220 /* 221 ** macro executed during Lua functions at points where the 222 ** function can yield. 223 */ 224 #if !defined(luai_threadyield) 225 #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} 226 #endif 227 228 229 /* 230 ** these macros allow user-specific actions on threads when you defined 231 ** LUAI_EXTRASPACE and need to do something extra when a thread is 232 ** created/deleted/resumed/yielded. 233 */ 234 #if !defined(luai_userstateopen) 235 #define luai_userstateopen(L) ((void)L) 236 #endif 237 238 #if !defined(luai_userstateclose) 239 #define luai_userstateclose(L) ((void)L) 240 #endif 241 242 #if !defined(luai_userstatethread) 243 #define luai_userstatethread(L,L1) ((void)L) 244 #endif 245 246 #if !defined(luai_userstatefree) 247 #define luai_userstatefree(L,L1) ((void)L) 248 #endif 249 250 #if !defined(luai_userstateresume) 251 #define luai_userstateresume(L,n) ((void)L) 252 #endif 253 254 #if !defined(luai_userstateyield) 255 #define luai_userstateyield(L,n) ((void)L) 256 #endif 257 258 259 260 /* 261 ** The luai_num* macros define the primitive operations over numbers. 262 */ 263 264 /* floor division (defined as 'floor(a/b)') */ 265 #if !defined(luai_numidiv) 266 #define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) 267 #endif 268 269 /* float division */ 270 #if !defined(luai_numdiv) 271 #define luai_numdiv(L,a,b) ((a)/(b)) 272 #endif 273 274 /* 275 ** modulo: defined as 'a - floor(a/b)*b'; this definition gives NaN when 276 ** 'b' is huge, but the result should be 'a'. 'fmod' gives the result of 277 ** 'a - trunc(a/b)*b', and therefore must be corrected when 'trunc(a/b) 278 ** ~= floor(a/b)'. That happens when the division has a non-integer 279 ** negative result, which is equivalent to the test below. 280 */ 281 #if !defined(luai_nummod) 282 #define luai_nummod(L,a,b,m) \ 283 { (m) = l_mathop(fmod)(a,b); if ((m)*(b) < 0) (m) += (b); } 284 #endif 285 286 /* exponentiation */ 287 #if !defined(luai_numpow) 288 #define luai_numpow(L,a,b) ((void)L, l_mathop(pow)(a,b)) 289 #endif 290 291 /* the others are quite standard operations */ 292 #if !defined(luai_numadd) 293 #define luai_numadd(L,a,b) ((a)+(b)) 294 #define luai_numsub(L,a,b) ((a)-(b)) 295 #define luai_nummul(L,a,b) ((a)*(b)) 296 #define luai_numunm(L,a) (-(a)) 297 #define luai_numeq(a,b) ((a)==(b)) 298 #define luai_numlt(a,b) ((a)<(b)) 299 #define luai_numle(a,b) ((a)<=(b)) 300 #define luai_numisnan(a) (!luai_numeq((a), (a))) 301 #endif 302 303 304 305 306 307 /* 308 ** macro to control inclusion of some hard tests on stack reallocation 309 */ 310 #if !defined(HARDSTACKTESTS) 311 #define condmovestack(L,pre,pos) ((void)0) 312 #else 313 /* realloc stack keeping its size */ 314 #define condmovestack(L,pre,pos) \ 315 { int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_); pos; } 316 #endif 317 318 #if !defined(HARDMEMTESTS) 319 #define condchangemem(L,pre,pos) ((void)0) 320 #else 321 #define condchangemem(L,pre,pos) \ 322 { if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } } 323 #endif 324 325 #endif 326