/*
** $Id: llimits.h,v 1.141 2015/11/19 19:16:22 roberto Exp $
** Limits, basic types, and some other 'installation-dependent' definitions
** See Copyright Notice in lua.h
*/

#ifndef llimits_h
#define llimits_h

#include <limits.h>
#include <stddef.h>

#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_BITSINT >= 32 /* }{ */
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;

/* 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 */

/*
** 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))

/* type to ensure maximum alignment */
#if defined(LUAI_USER_ALIGNMENT_T)
typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
#else
typedef union {
	lua_Number n;
	double u;
	void* s;
	lua_Integer i;
	long l;
} L_Umaxalign;
#endif

/* 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) 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_byte(i) cast(lu_byte, (i))
#define cast_num(i) cast(lua_Number, (i))
#define cast_int(i) cast(int, (i))
#define cast_uchar(i) cast(unsigned char, (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

/*
** non-return type
*/
#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

/*
** maximum depth for nested C calls and syntactical nested non-terminals
** in a program. (Value must fit in an unsigned short int.)
*/
#if !defined(LUAI_MAXCCALLS)
#define LUAI_MAXCCALLS 200
#endif

/*
** type for virtual-machine instructions;
** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
*/
#if LUAI_BITSINT >= 32
typedef unsigned int Instruction;
#else
typedef unsigned long Instruction;
#endif

/*
** 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 on threads when you defined
** LUAI_EXTRASPACE and need to do something extra 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'; this definition gives NaN when
** 'b' is huge, but the result should be 'a'. '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, which is equivalent to the test below.
*/
#if !defined(luai_nummod)
#define luai_nummod(L, a, b, m)                                                                    \
	{                                                                                               \
		(m) = l_mathop(fmod)(a, b);                                                                  \
		if ((m) * (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_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_);                                                                 \
		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
