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 double u; 70 void *s; 71 lua_Integer i; 72 long l; 73 } L_Umaxalign; 74 #endif 75 76 77 78 /* types of 'usual argument conversions' for lua_Number and lua_Integer */ 79 typedef LUAI_UACNUMBER l_uacNumber; 80 typedef LUAI_UACINT l_uacInt; 81 82 83 /* internal assertions for in-house debugging */ 84 #if defined(lua_assert) 85 #define check_exp(c,e) (lua_assert(c), (e)) 86 /* to avoid problems with conditions too long */ 87 #define lua_longassert(c) ((c) ? (void)0 : lua_assert(0)) 88 #else 89 #define lua_assert(c) ((void)0) 90 #define check_exp(c,e) (e) 91 #define lua_longassert(c) ((void)0) 92 #endif 93 94 /* 95 ** assertion for checking API calls 96 */ 97 #if !defined(luai_apicheck) 98 #define luai_apicheck(l,e) lua_assert(e) 99 #endif 100 101 #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) 102 103 104 /* macro to avoid warnings about unused variables */ 105 #if !defined(UNUSED) 106 #define UNUSED(x) ((void)(x)) 107 #endif 108 109 110 /* type casts (a macro highlights casts in the code) */ 111 #define cast(t, exp) ((t)(exp)) 112 113 #define cast_void(i) cast(void, (i)) 114 #define cast_byte(i) cast(lu_byte, (i)) 115 #define cast_num(i) cast(lua_Number, (i)) 116 #define cast_int(i) cast(int, (i)) 117 #define cast_uchar(i) cast(unsigned char, (i)) 118 119 120 /* cast a signed lua_Integer to lua_Unsigned */ 121 #if !defined(l_castS2U) 122 #define l_castS2U(i) ((lua_Unsigned)(i)) 123 #endif 124 125 /* 126 ** cast a lua_Unsigned to a signed lua_Integer; this cast is 127 ** not strict ISO C, but two-complement architectures should 128 ** work fine. 129 */ 130 #if !defined(l_castU2S) 131 #define l_castU2S(i) ((lua_Integer)(i)) 132 #endif 133 134 135 /* 136 ** non-return type 137 */ 138 #if defined(__GNUC__) 139 #define l_noret void __attribute__((noreturn)) 140 #elif defined(_MSC_VER) && _MSC_VER >= 1200 141 #define l_noret void __declspec(noreturn) 142 #else 143 #define l_noret void 144 #endif 145 146 147 148 /* 149 ** maximum depth for nested C calls and syntactical nested non-terminals 150 ** in a program. (Value must fit in an unsigned short int.) 151 */ 152 #if !defined(LUAI_MAXCCALLS) 153 #define LUAI_MAXCCALLS 200 154 #endif 155 156 157 158 /* 159 ** type for virtual-machine instructions; 160 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) 161 */ 162 #if LUAI_BITSINT >= 32 163 typedef unsigned int Instruction; 164 #else 165 typedef unsigned long Instruction; 166 #endif 167 168 169 170 /* 171 ** Maximum length for short strings, that is, strings that are 172 ** internalized. (Cannot be smaller than reserved words or tags for 173 ** metamethods, as these strings must be internalized; 174 ** #("function") = 8, #("__newindex") = 10.) 175 */ 176 #if !defined(LUAI_MAXSHORTLEN) 177 #define LUAI_MAXSHORTLEN 40 178 #endif 179 180 181 /* 182 ** Initial size for the string table (must be power of 2). 183 ** The Lua core alone registers ~50 strings (reserved words + 184 ** metaevent keys + a few others). Libraries would typically add 185 ** a few dozens more. 186 */ 187 #if !defined(MINSTRTABSIZE) 188 #define MINSTRTABSIZE 128 189 #endif 190 191 192 /* 193 ** Size of cache for strings in the API. 'N' is the number of 194 ** sets (better be a prime) and "M" is the size of each set (M == 1 195 ** makes a direct cache.) 196 */ 197 #if !defined(STRCACHE_N) 198 #define STRCACHE_N 53 199 #define STRCACHE_M 2 200 #endif 201 202 203 /* minimum size for string buffer */ 204 #if !defined(LUA_MINBUFFER) 205 #define LUA_MINBUFFER 32 206 #endif 207 208 209 /* 210 ** macros that are executed whenever program enters the Lua core 211 ** ('lua_lock') and leaves the core ('lua_unlock') 212 */ 213 #if !defined(lua_lock) 214 #define lua_lock(L) ((void) 0) 215 #define lua_unlock(L) ((void) 0) 216 #endif 217 218 /* 219 ** macro executed during Lua functions at points where the 220 ** function can yield. 221 */ 222 #if !defined(luai_threadyield) 223 #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} 224 #endif 225 226 227 /* 228 ** these macros allow user-specific actions on threads when you defined 229 ** LUAI_EXTRASPACE and need to do something extra when a thread is 230 ** created/deleted/resumed/yielded. 231 */ 232 #if !defined(luai_userstateopen) 233 #define luai_userstateopen(L) ((void)L) 234 #endif 235 236 #if !defined(luai_userstateclose) 237 #define luai_userstateclose(L) ((void)L) 238 #endif 239 240 #if !defined(luai_userstatethread) 241 #define luai_userstatethread(L,L1) ((void)L) 242 #endif 243 244 #if !defined(luai_userstatefree) 245 #define luai_userstatefree(L,L1) ((void)L) 246 #endif 247 248 #if !defined(luai_userstateresume) 249 #define luai_userstateresume(L,n) ((void)L) 250 #endif 251 252 #if !defined(luai_userstateyield) 253 #define luai_userstateyield(L,n) ((void)L) 254 #endif 255 256 257 258 /* 259 ** The luai_num* macros define the primitive operations over numbers. 260 */ 261 262 /* floor division (defined as 'floor(a/b)') */ 263 #if !defined(luai_numidiv) 264 #define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) 265 #endif 266 267 /* float division */ 268 #if !defined(luai_numdiv) 269 #define luai_numdiv(L,a,b) ((a)/(b)) 270 #endif 271 272 /* 273 ** modulo: defined as 'a - floor(a/b)*b'; this definition gives NaN when 274 ** 'b' is huge, but the result should be 'a'. 'fmod' gives the result of 275 ** 'a - trunc(a/b)*b', and therefore must be corrected when 'trunc(a/b) 276 ** ~= floor(a/b)'. That happens when the division has a non-integer 277 ** negative result, which is equivalent to the test below. 278 */ 279 #if !defined(luai_nummod) 280 #define luai_nummod(L,a,b,m) \ 281 { (m) = l_mathop(fmod)(a,b); if ((m)*(b) < 0) (m) += (b); } 282 #endif 283 284 /* exponentiation */ 285 #if !defined(luai_numpow) 286 #define luai_numpow(L,a,b) ((void)L, l_mathop(pow)(a,b)) 287 #endif 288 289 /* the others are quite standard operations */ 290 #if !defined(luai_numadd) 291 #define luai_numadd(L,a,b) ((a)+(b)) 292 #define luai_numsub(L,a,b) ((a)-(b)) 293 #define luai_nummul(L,a,b) ((a)*(b)) 294 #define luai_numunm(L,a) (-(a)) 295 #define luai_numeq(a,b) ((a)==(b)) 296 #define luai_numlt(a,b) ((a)<(b)) 297 #define luai_numle(a,b) ((a)<=(b)) 298 #define luai_numisnan(a) (!luai_numeq((a), (a))) 299 #endif 300 301 302 303 304 305 /* 306 ** macro to control inclusion of some hard tests on stack reallocation 307 */ 308 #if !defined(HARDSTACKTESTS) 309 #define condmovestack(L,pre,pos) ((void)0) 310 #else 311 /* realloc stack keeping its size */ 312 #define condmovestack(L,pre,pos) \ 313 { int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_); pos; } 314 #endif 315 316 #if !defined(HARDMEMTESTS) 317 #define condchangemem(L,pre,pos) ((void)0) 318 #else 319 #define condchangemem(L,pre,pos) \ 320 { if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } } 321 #endif 322 323 #endif 324