/* ** $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' is an unsigned integer big enough to count the total memory ** used by Lua (in bytes). 'l_obj' is a signed integer big enough to ** count the total number of objects used by Lua. (It is signed due ** to the use of debt in several computations.) 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_obj; #elif LUAI_IS32INT /* }{ */ typedef size_t lu_mem; typedef ptrdiff_t l_obj; #else /* 16-bit ints */ /* }{ */ typedef unsigned long lu_mem; typedef long l_obj; #endif /* } */ #define MAX_LOBJ \ cast(l_obj, (cast(lu_mem, 1) << (sizeof(l_obj) * CHAR_BIT - 1)) - 1) /* 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 for strings and userdata visible for Lua; should be ** representable as a lua_Integer and as a size_t. */ #define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ : cast_sizet(LUA_MAXINTEGER)) /* ** 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) cast_int(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. (In strict ISO C this may cause undefined behavior, but no ** actual machine seems to bother.) */ #if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \ __STDC_VERSION__ >= 199901L #include #if defined(UINTPTR_MAX) /* even in C99 this type is optional */ #define L_P2I uintptr_t #else /* no 'intptr'? */ #define L_P2I uintmax_t /* use the largest available integer */ #endif #else /* C89 option */ #define L_P2I size_t #endif #define point2uint(p) cast_uint((L_P2I)(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 LUAI_ASSERT #undef NDEBUG #include #define lua_assert(c) assert(c) #endif #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 /* 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_ulong(i) cast(unsigned long, (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 /* ** cast a size_t to lua_Integer: These casts are always valid for ** sizes of Lua objects (see MAX_SIZE) */ #define cast_st2S(sz) ((lua_Integer)(sz)) /* Cast a ptrdiff_t to size_t, when it is known that the minuend ** comes from the subtraend (the base) */ #define ct_diff2sz(df) ((size_t)(df)) /* ptrdiff_t to lua_Integer */ #define ct_diff2S(df) cast_st2S(ct_diff2sz(df)) /* ** Special type equivalent to '(void*)' for functions (to suppress some ** warnings when converting function pointers) */ typedef void (*voidf)(void); /* ** Macro to convert pointer-to-void* to pointer-to-function. This cast ** is undefined according to ISO C, but POSIX assumes that it works. ** (The '__extension__' in gnu compilers is only to avoid warnings.) */ #if defined(__GNUC__) #define cast_func(p) (__extension__ (voidf)(p)) #else #define cast_func(p) ((voidf)(p)) #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 /* ** Inline functions */ #if !defined(LUA_USE_C89) #define l_inline inline #elif defined(__GNUC__) #define l_inline __inline__ #else #define l_inline /* empty */ #endif #define l_sinline static l_inline /* ** An unsigned with (at least) 4 bytes */ #if LUAI_IS32INT typedef unsigned int l_uint32; #else typedef unsigned long l_uint32; #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, (b == 2) ? (a)*(a) : 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 /* ** {================================================================== ** "Abstraction Layer" for basic report of messages and errors ** =================================================================== */ /* print a string */ #if !defined(lua_writestring) #define lua_writestring(s,l) fwrite((s), sizeof(char), (l), stdout) #endif /* print a newline and flush the output */ #if !defined(lua_writeline) #define lua_writeline() (lua_writestring("\n", 1), fflush(stdout)) #endif /* print an error message */ #if !defined(lua_writestringerror) #define lua_writestringerror(s,p) \ (fprintf(stderr, (s), (p)), fflush(stderr)) #endif /* }================================================================== */ #endif