1 /* 2 ** $Id: llimits.h,v 1.103.1.1 2013/04/12 18:48:47 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 <sys/lua/lua.h> 12 13 14 typedef unsigned LUA_INT32 lu_int32; 15 16 typedef LUAI_UMEM lu_mem; 17 18 typedef LUAI_MEM l_mem; 19 20 21 22 /* chars used as small naturals (so that `char' is reserved for characters) */ 23 typedef unsigned char lu_byte; 24 25 26 #define MAX_SIZET ((size_t)(~(size_t)0)-2) 27 28 #define MAX_LUMEM ((lu_mem)(~(lu_mem)0)-2) 29 30 #define MAX_LMEM ((l_mem) ((MAX_LUMEM >> 1) - 2)) 31 32 33 #define MAX_INT (INT_MAX-2) /* maximum value of an int (-2 for safety) */ 34 35 /* 36 ** conversion of pointer to integer 37 ** this is for hashing only; there is no problem if the integer 38 ** cannot hold the whole pointer value 39 */ 40 #define IntPoint(p) ((unsigned int)(lu_mem)(p)) 41 42 43 44 /* type to ensure maximum alignment */ 45 #if !defined(LUAI_USER_ALIGNMENT_T) 46 #define LUAI_USER_ALIGNMENT_T union { double u; void *s; long l; } 47 #endif 48 49 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign; 50 51 52 /* result of a `usual argument conversion' over lua_Number */ 53 typedef LUAI_UACNUMBER l_uacNumber; 54 55 56 /* internal assertions for in-house debugging */ 57 #if defined(lua_assert) 58 #define check_exp(c,e) (lua_assert(c), (e)) 59 /* to avoid problems with conditions too long */ 60 #define lua_longassert(c) { if (!(c)) lua_assert(0); } 61 #else 62 #define lua_assert(c) ((void)0) 63 #define check_exp(c,e) (e) 64 #define lua_longassert(c) ((void)0) 65 #endif 66 67 /* 68 ** assertion for checking API calls 69 */ 70 #if !defined(luai_apicheck) 71 72 #if defined(LUA_USE_APICHECK) 73 #include <assert.h> 74 #define luai_apicheck(L,e) assert(e) 75 #else 76 #define luai_apicheck(L,e) lua_assert(e) 77 #endif 78 79 #endif 80 81 #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) 82 83 84 #if !defined(UNUSED) 85 #define UNUSED(x) ((void)(x)) /* to avoid warnings */ 86 #endif 87 88 89 #define cast(t, exp) ((t)(exp)) 90 91 #define cast_byte(i) cast(lu_byte, (i)) 92 #define cast_num(i) cast(lua_Number, (i)) 93 #define cast_int(i) cast(int, (i)) 94 #define cast_uchar(i) cast(unsigned char, (i)) 95 96 97 /* 98 ** non-return type 99 ** 100 ** Suppress noreturn attribute in kernel builds to avoid objtool check warnings 101 */ 102 #if defined(__GNUC__) && !defined(_KERNEL) 103 #define l_noret void __attribute__((noreturn)) 104 #elif defined(_MSC_VER) 105 #define l_noret void __declspec(noreturn) 106 #else 107 #define l_noret void 108 #endif 109 110 111 112 /* 113 ** maximum depth for nested C calls and syntactical nested non-terminals 114 ** in a program. (Value must fit in an unsigned short int.) 115 ** 116 ** Note: On amd64 platform, the limit has been measured to be 45. We set 117 ** the maximum lower to give a margin for changing the amount of stack 118 ** used by various functions involved in parsing and executing code. 119 */ 120 #if !defined(LUAI_MAXCCALLS) 121 #define LUAI_MAXCCALLS 20 122 #endif 123 124 /* 125 * Minimum amount of available stack space (in bytes) to make a C call. With 126 * gsub() recursion, the stack space between each luaD_call() is 1256 bytes. 127 */ 128 #define LUAI_MINCSTACK 4096 129 130 /* 131 ** maximum number of upvalues in a closure (both C and Lua). (Value 132 ** must fit in an unsigned char.) 133 */ 134 #define MAXUPVAL UCHAR_MAX 135 136 137 /* 138 ** type for virtual-machine instructions 139 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) 140 */ 141 typedef lu_int32 Instruction; 142 143 144 145 /* maximum stack for a Lua function */ 146 #define MAXSTACK 250 147 148 149 150 /* minimum size for the string table (must be power of 2) */ 151 #if !defined(MINSTRTABSIZE) 152 #define MINSTRTABSIZE 32 153 #endif 154 155 156 /* minimum size for string buffer */ 157 #if !defined(LUA_MINBUFFER) 158 #define LUA_MINBUFFER 32 159 #endif 160 161 162 #if !defined(lua_lock) 163 #define lua_lock(L) ((void) 0) 164 #define lua_unlock(L) ((void) 0) 165 #endif 166 167 #if !defined(luai_threadyield) 168 #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} 169 #endif 170 171 172 /* 173 ** these macros allow user-specific actions on threads when you defined 174 ** LUAI_EXTRASPACE and need to do something extra when a thread is 175 ** created/deleted/resumed/yielded. 176 */ 177 #if !defined(luai_userstateopen) 178 #define luai_userstateopen(L) ((void)L) 179 #endif 180 181 #if !defined(luai_userstateclose) 182 #define luai_userstateclose(L) ((void)L) 183 #endif 184 185 #if !defined(luai_userstatethread) 186 #define luai_userstatethread(L,L1) ((void)L) 187 #endif 188 189 #if !defined(luai_userstatefree) 190 #define luai_userstatefree(L,L1) ((void)L) 191 #endif 192 193 #if !defined(luai_userstateresume) 194 #define luai_userstateresume(L,n) ((void)L) 195 #endif 196 197 #if !defined(luai_userstateyield) 198 #define luai_userstateyield(L,n) ((void)L) 199 #endif 200 201 /* 202 ** lua_number2int is a macro to convert lua_Number to int. 203 ** lua_number2integer is a macro to convert lua_Number to lua_Integer. 204 ** lua_number2unsigned is a macro to convert a lua_Number to a lua_Unsigned. 205 ** lua_unsigned2number is a macro to convert a lua_Unsigned to a lua_Number. 206 ** luai_hashnum is a macro to hash a lua_Number value into an integer. 207 ** The hash must be deterministic and give reasonable values for 208 ** both small and large values (outside the range of integers). 209 */ 210 211 #if defined(MS_ASMTRICK) || defined(LUA_MSASMTRICK) /* { */ 212 /* trick with Microsoft assembler for X86 */ 213 214 #define lua_number2int(i,n) __asm {__asm fld n __asm fistp i} 215 #define lua_number2integer(i,n) lua_number2int(i, n) 216 #define lua_number2unsigned(i,n) \ 217 {__int64 l; __asm {__asm fld n __asm fistp l} i = (unsigned int)l;} 218 219 220 #elif defined(LUA_IEEE754TRICK) /* }{ */ 221 /* the next trick should work on any machine using IEEE754 with 222 a 32-bit int type */ 223 224 union luai_Cast { double l_d; LUA_INT32 l_p[2]; }; 225 226 #if !defined(LUA_IEEEENDIAN) /* { */ 227 #define LUAI_EXTRAIEEE \ 228 static const union luai_Cast ieeeendian = {-(33.0 + 6755399441055744.0)}; 229 #define LUA_IEEEENDIANLOC (ieeeendian.l_p[1] == 33) 230 #else 231 #define LUA_IEEEENDIANLOC LUA_IEEEENDIAN 232 #define LUAI_EXTRAIEEE /* empty */ 233 #endif /* } */ 234 235 #define lua_number2int32(i,n,t) \ 236 { LUAI_EXTRAIEEE \ 237 volatile union luai_Cast u; u.l_d = (n) + 6755399441055744.0; \ 238 (i) = (t)u.l_p[LUA_IEEEENDIANLOC]; } 239 240 #define luai_hashnum(i,n) \ 241 { volatile union luai_Cast u; u.l_d = (n) + 1.0; /* avoid -0 */ \ 242 (i) = u.l_p[0]; (i) += u.l_p[1]; } /* add double bits for his hash */ 243 244 #define lua_number2int(i,n) lua_number2int32(i, n, int) 245 #define lua_number2unsigned(i,n) lua_number2int32(i, n, lua_Unsigned) 246 247 /* the trick can be expanded to lua_Integer when it is a 32-bit value */ 248 #if defined(LUA_IEEELL) 249 #define lua_number2integer(i,n) lua_number2int32(i, n, lua_Integer) 250 #endif 251 252 #endif /* } */ 253 254 255 /* the following definitions always work, but may be slow */ 256 257 #if !defined(lua_number2int) 258 #define lua_number2int(i,n) ((i)=(int)(n)) 259 #endif 260 261 #if !defined(lua_number2integer) 262 #define lua_number2integer(i,n) ((i)=(lua_Integer)(n)) 263 #endif 264 265 #if !defined(lua_number2unsigned) /* { */ 266 /* the following definition assures proper modulo behavior */ 267 #if defined(LUA_NUMBER_DOUBLE) || defined(LUA_NUMBER_FLOAT) 268 #include <math.h> 269 #define SUPUNSIGNED ((lua_Number)(~(lua_Unsigned)0) + 1) 270 #define lua_number2unsigned(i,n) \ 271 ((i)=(lua_Unsigned)((n) - floor((n)/SUPUNSIGNED)*SUPUNSIGNED)) 272 #else 273 #define lua_number2unsigned(i,n) ((i)=(lua_Unsigned)(n)) 274 #endif 275 #endif /* } */ 276 277 278 #if !defined(lua_unsigned2number) 279 /* on several machines, coercion from unsigned to double is slow, 280 so it may be worth to avoid */ 281 #define lua_unsigned2number(u) \ 282 (((u) <= (lua_Unsigned)INT_MAX) ? (lua_Number)(int)(u) : (lua_Number)(u)) 283 #endif 284 285 286 287 #if defined(ltable_c) && !defined(luai_hashnum) 288 289 #define luai_hashnum(i,n) (i = lcompat_hashnum(n)) 290 291 #endif 292 293 294 295 /* 296 ** macro to control inclusion of some hard tests on stack reallocation 297 */ 298 #if !defined(HARDSTACKTESTS) 299 #define condmovestack(L) ((void)0) 300 #else 301 /* realloc stack keeping its size */ 302 #define condmovestack(L) luaD_reallocstack((L), (L)->stacksize) 303 #endif 304 305 #if !defined(HARDMEMTESTS) 306 #define condchangemem(L) condmovestack(L) 307 #else 308 #define condchangemem(L) \ 309 ((void)(!(G(L)->gcrunning) || (luaC_fullgc(L, 0), 1))) 310 #endif 311 312 #endif 313