llimits.h revision 344220
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? */ 23typedef LUAI_UMEM lu_mem; 24typedef LUAI_MEM l_mem; 25#elif LUAI_BITSINT >= 32 /* }{ */ 26typedef size_t lu_mem; 27typedef ptrdiff_t l_mem; 28#else /* 16-bit ints */ /* }{ */ 29typedef unsigned long lu_mem; 30typedef long l_mem; 31#endif /* } */ 32 33 34/* chars used as small naturals (so that 'char' is reserved for characters) */ 35typedef 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) 65typedef LUAI_USER_ALIGNMENT_T L_Umaxalign; 66#else 67typedef 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 */ 81typedef LUAI_UACNUMBER l_uacNumber; 82typedef 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 165typedef unsigned int Instruction; 166#else 167typedef 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