1 /* BEGIN CSTYLED */ 2 /* 3 ** $Id: llimits.h,v 1.103.1.1 2013/04/12 18:48:47 roberto Exp $ 4 ** Limits, basic types, and some other `installation-dependent' definitions 5 ** See Copyright Notice in lua.h 6 */ 7 8 #ifndef llimits_h 9 #define llimits_h 10 11 12 #include <sys/lua/lua.h> 13 14 15 typedef unsigned LUA_INT32 lu_int32; 16 17 typedef LUAI_UMEM lu_mem; 18 19 typedef LUAI_MEM l_mem; 20 21 22 23 /* chars used as small naturals (so that `char' is reserved for characters) */ 24 typedef unsigned char lu_byte; 25 26 27 #define MAX_SIZET ((size_t)(~(size_t)0)-2) 28 29 #define MAX_LUMEM ((lu_mem)(~(lu_mem)0)-2) 30 31 #define MAX_LMEM ((l_mem) ((MAX_LUMEM >> 1) - 2)) 32 33 34 #define MAX_INT (INT_MAX-2) /* maximum value of an int (-2 for safety) */ 35 36 /* 37 ** conversion of pointer to integer 38 ** this is for hashing only; there is no problem if the integer 39 ** cannot hold the whole pointer value 40 */ 41 #define IntPoint(p) ((unsigned int)(lu_mem)(p)) 42 43 44 45 /* type to ensure maximum alignment */ 46 #if !defined(LUAI_USER_ALIGNMENT_T) 47 #define LUAI_USER_ALIGNMENT_T union { double u; void *s; long l; } 48 #endif 49 50 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign; 51 52 53 /* result of a `usual argument conversion' over lua_Number */ 54 typedef LUAI_UACNUMBER l_uacNumber; 55 56 57 /* internal assertions for in-house debugging */ 58 #if defined(lua_assert) 59 #define check_exp(c,e) (lua_assert(c), (e)) 60 /* to avoid problems with conditions too long */ 61 #define lua_longassert(c) { if (!(c)) lua_assert(0); } 62 #else 63 #define lua_assert(c) ((void)0) 64 #define check_exp(c,e) (e) 65 #define lua_longassert(c) ((void)0) 66 #endif 67 68 /* 69 ** assertion for checking API calls 70 */ 71 #if !defined(luai_apicheck) 72 73 #if defined(LUA_USE_APICHECK) 74 #include <assert.h> 75 #define luai_apicheck(L,e) assert(e) 76 #else 77 #define luai_apicheck(L,e) lua_assert(e) 78 #endif 79 80 #endif 81 82 #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) 83 84 85 #if !defined(UNUSED) 86 #define UNUSED(x) ((void)(x)) /* to avoid warnings */ 87 #endif 88 89 90 #define cast(t, exp) ((t)(exp)) 91 92 #define cast_byte(i) cast(lu_byte, (i)) 93 #define cast_num(i) cast(lua_Number, (i)) 94 #define cast_int(i) cast(int, (i)) 95 #define cast_uchar(i) cast(unsigned char, (i)) 96 97 98 /* 99 ** non-return type 100 ** 101 ** Suppress noreturn attribute in kernel builds to avoid objtool check warnings 102 */ 103 #if defined(__GNUC__) && !defined(_KERNEL) 104 #define l_noret void __attribute__((noreturn)) 105 #elif defined(_MSC_VER) 106 #define l_noret void __declspec(noreturn) 107 #else 108 #define l_noret void 109 #endif 110 111 112 113 /* 114 ** maximum depth for nested C calls and syntactical nested non-terminals 115 ** in a program. (Value must fit in an unsigned short int.) 116 ** 117 ** Note: On amd64 platform, the limit has been measured to be 45. We set 118 ** the maximum lower to give a margin for changing the amount of stack 119 ** used by various functions involved in parsing and executing code. 120 */ 121 #if !defined(LUAI_MAXCCALLS) 122 #define LUAI_MAXCCALLS 20 123 #endif 124 125 /* 126 * Minimum amount of available stack space (in bytes) to make a C call. With 127 * gsub() recursion, the stack space between each luaD_call() is 1256 bytes. 128 */ 129 #if defined(__FreeBSD__) 130 /* 131 * FreeBSD needs a few extra bytes in unoptimized debug builds to avoid a 132 * double-fault handling the error when the max call depth is exceeded just 133 * before the C stack runs out. 64 bytes seems to do the trick. 134 */ 135 #define LUAI_MINCSTACK 4160 136 #else 137 #define LUAI_MINCSTACK 4096 138 #endif 139 140 /* 141 ** maximum number of upvalues in a closure (both C and Lua). (Value 142 ** must fit in an unsigned char.) 143 */ 144 #define MAXUPVAL UCHAR_MAX 145 146 147 /* 148 ** type for virtual-machine instructions 149 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) 150 */ 151 typedef lu_int32 Instruction; 152 153 154 155 /* maximum stack for a Lua function */ 156 #define MAXSTACK 250 157 158 159 160 /* minimum size for the string table (must be power of 2) */ 161 #if !defined(MINSTRTABSIZE) 162 #define MINSTRTABSIZE 32 163 #endif 164 165 166 /* minimum size for string buffer */ 167 #if !defined(LUA_MINBUFFER) 168 #define LUA_MINBUFFER 32 169 #endif 170 171 172 #if !defined(lua_lock) 173 #define lua_lock(L) ((void) 0) 174 #define lua_unlock(L) ((void) 0) 175 #endif 176 177 #if !defined(luai_threadyield) 178 #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} 179 #endif 180 181 182 /* 183 ** these macros allow user-specific actions on threads when you defined 184 ** LUAI_EXTRASPACE and need to do something extra when a thread is 185 ** created/deleted/resumed/yielded. 186 */ 187 #if !defined(luai_userstateopen) 188 #define luai_userstateopen(L) ((void)L) 189 #endif 190 191 #if !defined(luai_userstateclose) 192 #define luai_userstateclose(L) ((void)L) 193 #endif 194 195 #if !defined(luai_userstatethread) 196 #define luai_userstatethread(L,L1) ((void)L) 197 #endif 198 199 #if !defined(luai_userstatefree) 200 #define luai_userstatefree(L,L1) ((void)L) 201 #endif 202 203 #if !defined(luai_userstateresume) 204 #define luai_userstateresume(L,n) ((void)L) 205 #endif 206 207 #if !defined(luai_userstateyield) 208 #define luai_userstateyield(L,n) ((void)L) 209 #endif 210 211 /* 212 ** lua_number2int is a macro to convert lua_Number to int. 213 ** lua_number2integer is a macro to convert lua_Number to lua_Integer. 214 ** lua_number2unsigned is a macro to convert a lua_Number to a lua_Unsigned. 215 ** lua_unsigned2number is a macro to convert a lua_Unsigned to a lua_Number. 216 ** luai_hashnum is a macro to hash a lua_Number value into an integer. 217 ** The hash must be deterministic and give reasonable values for 218 ** both small and large values (outside the range of integers). 219 */ 220 221 #if defined(MS_ASMTRICK) || defined(LUA_MSASMTRICK) /* { */ 222 /* trick with Microsoft assembler for X86 */ 223 224 #define lua_number2int(i,n) __asm {__asm fld n __asm fistp i} 225 #define lua_number2integer(i,n) lua_number2int(i, n) 226 #define lua_number2unsigned(i,n) \ 227 {__int64 l; __asm {__asm fld n __asm fistp l} i = (unsigned int)l;} 228 229 230 #elif defined(LUA_IEEE754TRICK) /* }{ */ 231 /* the next trick should work on any machine using IEEE754 with 232 a 32-bit int type */ 233 234 union luai_Cast { double l_d; LUA_INT32 l_p[2]; }; 235 236 #if !defined(LUA_IEEEENDIAN) /* { */ 237 #define LUAI_EXTRAIEEE \ 238 static const union luai_Cast ieeeendian = {-(33.0 + 6755399441055744.0)}; 239 #define LUA_IEEEENDIANLOC (ieeeendian.l_p[1] == 33) 240 #else 241 #define LUA_IEEEENDIANLOC LUA_IEEEENDIAN 242 #define LUAI_EXTRAIEEE /* empty */ 243 #endif /* } */ 244 245 #define lua_number2int32(i,n,t) \ 246 { LUAI_EXTRAIEEE \ 247 volatile union luai_Cast u; u.l_d = (n) + 6755399441055744.0; \ 248 (i) = (t)u.l_p[LUA_IEEEENDIANLOC]; } 249 250 #define luai_hashnum(i,n) \ 251 { volatile union luai_Cast u; u.l_d = (n) + 1.0; /* avoid -0 */ \ 252 (i) = u.l_p[0]; (i) += u.l_p[1]; } /* add double bits for his hash */ 253 254 #define lua_number2int(i,n) lua_number2int32(i, n, int) 255 #define lua_number2unsigned(i,n) lua_number2int32(i, n, lua_Unsigned) 256 257 /* the trick can be expanded to lua_Integer when it is a 32-bit value */ 258 #if defined(LUA_IEEELL) 259 #define lua_number2integer(i,n) lua_number2int32(i, n, lua_Integer) 260 #endif 261 262 #endif /* } */ 263 264 265 /* the following definitions always work, but may be slow */ 266 267 #if !defined(lua_number2int) 268 #define lua_number2int(i,n) ((i)=(int)(n)) 269 #endif 270 271 #if !defined(lua_number2integer) 272 #define lua_number2integer(i,n) ((i)=(lua_Integer)(n)) 273 #endif 274 275 #if !defined(lua_number2unsigned) /* { */ 276 /* the following definition assures proper modulo behavior */ 277 #if defined(LUA_NUMBER_DOUBLE) || defined(LUA_NUMBER_FLOAT) 278 #include <math.h> 279 #define SUPUNSIGNED ((lua_Number)(~(lua_Unsigned)0) + 1) 280 #define lua_number2unsigned(i,n) \ 281 ((i)=(lua_Unsigned)((n) - floor((n)/SUPUNSIGNED)*SUPUNSIGNED)) 282 #else 283 #define lua_number2unsigned(i,n) ((i)=(lua_Unsigned)(n)) 284 #endif 285 #endif /* } */ 286 287 288 #if !defined(lua_unsigned2number) 289 /* on several machines, coercion from unsigned to double is slow, 290 so it may be worth to avoid */ 291 #define lua_unsigned2number(u) \ 292 (((u) <= (lua_Unsigned)INT_MAX) ? (lua_Number)(int)(u) : (lua_Number)(u)) 293 #endif 294 295 296 297 #if defined(ltable_c) && !defined(luai_hashnum) 298 299 #define luai_hashnum(i,n) (i = lcompat_hashnum(n)) 300 301 #endif 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) ((void)0) 310 #else 311 /* realloc stack keeping its size */ 312 #define condmovestack(L) luaD_reallocstack((L), (L)->stacksize) 313 #endif 314 315 #if !defined(HARDMEMTESTS) 316 #define condchangemem(L) condmovestack(L) 317 #else 318 #define condchangemem(L) \ 319 ((void)(!(G(L)->gcrunning) || (luaC_fullgc(L, 0), 1))) 320 #endif 321 322 #endif 323 /* END CSTYLED */ 324