module/lua/llimits.h

   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