/* ** $Id: llimits.h $ ** Limits, basic types, and some other 'installation-dependent' definitions ** See Copyright Notice in lua.h */ #ifndef llimits_h #define llimits_h #include #include #include "lua.h" /* ** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count ** the total memory used by Lua (in bytes). Usually, 'size_t' and ** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines. */ #if defined(LUAI_MEM) /* { external definitions? */ typedef LUAI_UMEM lu_mem; typedef LUAI_MEM l_mem; #elif LUAI_IS32INT /* }{ */ typedef size_t lu_mem; typedef ptrdiff_t l_mem; #else /* 16-bit ints */ /* }{ */ typedef unsigned long lu_mem; typedef long l_mem; #endif /* } */ /* chars used as small naturals (so that 'char' is reserved for characters) */ typedef unsigned char lu_byte; typedef signed char ls_byte; /* maximum value for size_t */ #define MAX_SIZET ((size_t)(~(size_t)0)) /* maximum size visible for Lua (must be representable in a lua_Integer) */ #define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ : (size_t)(LUA_MAXINTEGER)) #define MAX_LUMEM ((lu_mem)(~(lu_mem)0)) #define MAX_LMEM ((l_mem)(MAX_LUMEM >> 1)) #define MAX_INT INT_MAX /* maximum value of an int */ /* ** floor of the log2 of the maximum signed value for integral type 't'. ** (That is, maximum 'n' such that '2^n' fits in the given signed type.) */ #define log2maxs(t) (sizeof(t) * 8 - 2) /* ** test whether an unsigned value is a power of 2 (or zero) */ #define ispow2(x) (((x) & ((x) - 1)) == 0) /* number of chars of a literal string without the ending \0 */ #define LL(x) (sizeof(x)/sizeof(char) - 1) /* ** conversion of pointer to unsigned integer: ** this is for hashing only; there is no problem if the integer ** cannot hold the whole pointer value */ #define point2uint(p) ((unsigned int)((size_t)(p) & UINT_MAX)) /* types of 'usual argument conversions' for lua_Number and lua_Integer */ typedef LUAI_UACNUMBER l_uacNumber; typedef LUAI_UACINT l_uacInt; /* internal assertions for in-house debugging */ #if defined(lua_assert) #define check_exp(c,e) (lua_assert(c), (e)) /* to avoid problems with conditions too long */ #define lua_longassert(c) ((c) ? (void)0 : lua_assert(0)) #else #define lua_assert(c) ((void)0) #define check_exp(c,e) (e) #define lua_longassert(c) ((void)0) #endif /* ** assertion for checking API calls */ #if !defined(luai_apicheck) #define luai_apicheck(l,e) ((void)l, lua_assert(e)) #endif #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) /* macro to avoid warnings about unused variables */ #if !defined(UNUSED) #define UNUSED(x) ((void)(x)) #endif /* type casts (a macro highlights casts in the code) */ #define cast(t, exp) ((t)(exp)) #define cast_void(i) cast(void, (i)) #define cast_voidp(i) cast(void *, (i)) #define cast_num(i) cast(lua_Number, (i)) #define cast_int(i) cast(int, (i)) #define cast_uint(i) cast(unsigned int, (i)) #define cast_byte(i) cast(lu_byte, (i)) #define cast_uchar(i) cast(unsigned char, (i)) #define cast_char(i) cast(char, (i)) #define cast_charp(i) cast(char *, (i)) #define cast_sizet(i) cast(size_t, (i)) /* cast a signed lua_Integer to lua_Unsigned */ #if !defined(l_castS2U) #define l_castS2U(i) ((lua_Unsigned)(i)) #endif /* ** cast a lua_Unsigned to a signed lua_Integer; this cast is ** not strict ISO C, but two-complement architectures should ** work fine. */ #if !defined(l_castU2S) #define l_castU2S(i) ((lua_Integer)(i)) #endif /* ** macros to improve jump prediction (used mainly for error handling) */ #if !defined(likely) #if defined(__GNUC__) #define likely(x) (__builtin_expect(((x) != 0), 1)) #define unlikely(x) (__builtin_expect(((x) != 0), 0)) #else #define likely(x) (x) #define unlikely(x) (x) #endif #endif /* ** non-return type */ #if !defined(l_noret) #if defined(__GNUC__) #define l_noret void __attribute__((noreturn)) #elif defined(_MSC_VER) && _MSC_VER >= 1200 #define l_noret void __declspec(noreturn) #else #define l_noret void #endif #endif /* ** type for virtual-machine instructions; ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) */ #if LUAI_IS32INT typedef unsigned int l_uint32; #else typedef unsigned long l_uint32; #endif typedef l_uint32 Instruction; /* ** Maximum length for short strings, that is, strings that are ** internalized. (Cannot be smaller than reserved words or tags for ** metamethods, as these strings must be internalized; ** #("function") = 8, #("__newindex") = 10.) */ #if !defined(LUAI_MAXSHORTLEN) #define LUAI_MAXSHORTLEN 40 #endif /* ** Initial size for the string table (must be power of 2). ** The Lua core alone registers ~50 strings (reserved words + ** metaevent keys + a few others). Libraries would typically add ** a few dozens more. */ #if !defined(MINSTRTABSIZE) #define MINSTRTABSIZE 128 #endif /* ** Size of cache for strings in the API. 'N' is the number of ** sets (better be a prime) and "M" is the size of each set (M == 1 ** makes a direct cache.) */ #if !defined(STRCACHE_N) #define STRCACHE_N 53 #define STRCACHE_M 2 #endif /* minimum size for string buffer */ #if !defined(LUA_MINBUFFER) #define LUA_MINBUFFER 32 #endif /* ** macros that are executed whenever program enters the Lua core ** ('lua_lock') and leaves the core ('lua_unlock') */ #if !defined(lua_lock) #define lua_lock(L) ((void) 0) #define lua_unlock(L) ((void) 0) #endif /* ** macro executed during Lua functions at points where the ** function can yield. */ #if !defined(luai_threadyield) #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} #endif /* ** these macros allow user-specific actions when a thread is ** created/deleted/resumed/yielded. */ #if !defined(luai_userstateopen) #define luai_userstateopen(L) ((void)L) #endif #if !defined(luai_userstateclose) #define luai_userstateclose(L) ((void)L) #endif #if !defined(luai_userstatethread) #define luai_userstatethread(L,L1) ((void)L) #endif #if !defined(luai_userstatefree) #define luai_userstatefree(L,L1) ((void)L) #endif #if !defined(luai_userstateresume) #define luai_userstateresume(L,n) ((void)L) #endif #if !defined(luai_userstateyield) #define luai_userstateyield(L,n) ((void)L) #endif /* ** The luai_num* macros define the primitive operations over numbers. */ /* floor division (defined as 'floor(a/b)') */ #if !defined(luai_numidiv) #define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) #endif /* float division */ #if !defined(luai_numdiv) #define luai_numdiv(L,a,b) ((a)/(b)) #endif /* ** modulo: defined as 'a - floor(a/b)*b'; the direct computation ** using this definition has several problems with rounding errors, ** so it is better to use 'fmod'. 'fmod' gives the result of ** 'a - trunc(a/b)*b', and therefore must be corrected when ** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a ** non-integer negative result: non-integer result is equivalent to ** a non-zero remainder 'm'; negative result is equivalent to 'a' and ** 'b' with different signs, or 'm' and 'b' with different signs ** (as the result 'm' of 'fmod' has the same sign of 'a'). */ #if !defined(luai_nummod) #define luai_nummod(L,a,b,m) \ { (void)L; (m) = l_mathop(fmod)(a,b); \ if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); } #endif /* exponentiation */ #if !defined(luai_numpow) #define luai_numpow(L,a,b) ((void)L, l_mathop(pow)(a,b)) #endif /* the others are quite standard operations */ #if !defined(luai_numadd) #define luai_numadd(L,a,b) ((a)+(b)) #define luai_numsub(L,a,b) ((a)-(b)) #define luai_nummul(L,a,b) ((a)*(b)) #define luai_numunm(L,a) (-(a)) #define luai_numeq(a,b) ((a)==(b)) #define luai_numlt(a,b) ((a)<(b)) #define luai_numle(a,b) ((a)<=(b)) #define luai_numgt(a,b) ((a)>(b)) #define luai_numge(a,b) ((a)>=(b)) #define luai_numisnan(a) (!luai_numeq((a), (a))) #endif /* ** macro to control inclusion of some hard tests on stack reallocation */ #if !defined(HARDSTACKTESTS) #define condmovestack(L,pre,pos) ((void)0) #else /* realloc stack keeping its size */ #define condmovestack(L,pre,pos) \ { int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_, 0); pos; } #endif #if !defined(HARDMEMTESTS) #define condchangemem(L,pre,pos) ((void)0) #else #define condchangemem(L,pre,pos) \ { if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } } #endif #endif