zombiezen.com/go/lua@v0.0.0-20231013005828-290725fb9140/internal/lua54/llimits.h (about)

     1  /*
     2  ** $Id: llimits.h $
     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  /*
    19  ** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count
    20  ** the total memory used by Lua (in bytes). Usually, 'size_t' and
    21  ** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines.
    22  */
    23  #if defined(LUAI_MEM)		/* { external definitions? */
    24  typedef LUAI_UMEM lu_mem;
    25  typedef LUAI_MEM l_mem;
    26  #elif LUAI_IS32INT	/* }{ */
    27  typedef size_t lu_mem;
    28  typedef ptrdiff_t l_mem;
    29  #else  /* 16-bit ints */	/* }{ */
    30  typedef unsigned long lu_mem;
    31  typedef long l_mem;
    32  #endif				/* } */
    33  
    34  
    35  /* chars used as small naturals (so that 'char' is reserved for characters) */
    36  typedef unsigned char lu_byte;
    37  typedef signed char ls_byte;
    38  
    39  
    40  /* maximum value for size_t */
    41  #define MAX_SIZET	((size_t)(~(size_t)0))
    42  
    43  /* maximum size visible for Lua (must be representable in a lua_Integer) */
    44  #define MAX_SIZE	(sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \
    45                            : (size_t)(LUA_MAXINTEGER))
    46  
    47  
    48  #define MAX_LUMEM	((lu_mem)(~(lu_mem)0))
    49  
    50  #define MAX_LMEM	((l_mem)(MAX_LUMEM >> 1))
    51  
    52  
    53  #define MAX_INT		INT_MAX  /* maximum value of an int */
    54  
    55  
    56  /*
    57  ** floor of the log2 of the maximum signed value for integral type 't'.
    58  ** (That is, maximum 'n' such that '2^n' fits in the given signed type.)
    59  */
    60  #define log2maxs(t)	(sizeof(t) * 8 - 2)
    61  
    62  
    63  /*
    64  ** test whether an unsigned value is a power of 2 (or zero)
    65  */
    66  #define ispow2(x)	(((x) & ((x) - 1)) == 0)
    67  
    68  
    69  /* number of chars of a literal string without the ending \0 */
    70  #define LL(x)   (sizeof(x)/sizeof(char) - 1)
    71  
    72  
    73  /*
    74  ** conversion of pointer to unsigned integer: this is for hashing only;
    75  ** there is no problem if the integer cannot hold the whole pointer
    76  ** value. (In strict ISO C this may cause undefined behavior, but no
    77  ** actual machine seems to bother.)
    78  */
    79  #if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \
    80      __STDC_VERSION__ >= 199901L
    81  #include <stdint.h>
    82  #if defined(UINTPTR_MAX)  /* even in C99 this type is optional */
    83  #define L_P2I	uintptr_t
    84  #else  /* no 'intptr'? */
    85  #define L_P2I	uintmax_t  /* use the largest available integer */
    86  #endif
    87  #else  /* C89 option */
    88  #define L_P2I	size_t
    89  #endif
    90  
    91  #define point2uint(p)	((unsigned int)((L_P2I)(p) & UINT_MAX))
    92  
    93  
    94  
    95  /* types of 'usual argument conversions' for lua_Number and lua_Integer */
    96  typedef LUAI_UACNUMBER l_uacNumber;
    97  typedef LUAI_UACINT l_uacInt;
    98  
    99  
   100  /*
   101  ** Internal assertions for in-house debugging
   102  */
   103  #if defined LUAI_ASSERT
   104  #undef NDEBUG
   105  #include <assert.h>
   106  #define lua_assert(c)           assert(c)
   107  #endif
   108  
   109  #if defined(lua_assert)
   110  #define check_exp(c,e)		(lua_assert(c), (e))
   111  /* to avoid problems with conditions too long */
   112  #define lua_longassert(c)	((c) ? (void)0 : lua_assert(0))
   113  #else
   114  #define lua_assert(c)		((void)0)
   115  #define check_exp(c,e)		(e)
   116  #define lua_longassert(c)	((void)0)
   117  #endif
   118  
   119  /*
   120  ** assertion for checking API calls
   121  */
   122  #if !defined(luai_apicheck)
   123  #define luai_apicheck(l,e)	((void)l, lua_assert(e))
   124  #endif
   125  
   126  #define api_check(l,e,msg)	luai_apicheck(l,(e) && msg)
   127  
   128  
   129  /* macro to avoid warnings about unused variables */
   130  #if !defined(UNUSED)
   131  #define UNUSED(x)	((void)(x))
   132  #endif
   133  
   134  
   135  /* type casts (a macro highlights casts in the code) */
   136  #define cast(t, exp)	((t)(exp))
   137  
   138  #define cast_void(i)	cast(void, (i))
   139  #define cast_voidp(i)	cast(void *, (i))
   140  #define cast_num(i)	cast(lua_Number, (i))
   141  #define cast_int(i)	cast(int, (i))
   142  #define cast_uint(i)	cast(unsigned int, (i))
   143  #define cast_byte(i)	cast(lu_byte, (i))
   144  #define cast_uchar(i)	cast(unsigned char, (i))
   145  #define cast_char(i)	cast(char, (i))
   146  #define cast_charp(i)	cast(char *, (i))
   147  #define cast_sizet(i)	cast(size_t, (i))
   148  
   149  
   150  /* cast a signed lua_Integer to lua_Unsigned */
   151  #if !defined(l_castS2U)
   152  #define l_castS2U(i)	((lua_Unsigned)(i))
   153  #endif
   154  
   155  /*
   156  ** cast a lua_Unsigned to a signed lua_Integer; this cast is
   157  ** not strict ISO C, but two-complement architectures should
   158  ** work fine.
   159  */
   160  #if !defined(l_castU2S)
   161  #define l_castU2S(i)	((lua_Integer)(i))
   162  #endif
   163  
   164  
   165  /*
   166  ** non-return type
   167  */
   168  #if !defined(l_noret)
   169  
   170  #if defined(__GNUC__)
   171  #define l_noret		void __attribute__((noreturn))
   172  #elif defined(_MSC_VER) && _MSC_VER >= 1200
   173  #define l_noret		void __declspec(noreturn)
   174  #else
   175  #define l_noret		void
   176  #endif
   177  
   178  #endif
   179  
   180  
   181  /*
   182  ** Inline functions
   183  */
   184  #if !defined(LUA_USE_C89)
   185  #define l_inline	inline
   186  #elif defined(__GNUC__)
   187  #define l_inline	__inline__
   188  #else
   189  #define l_inline	/* empty */
   190  #endif
   191  
   192  #define l_sinline	static l_inline
   193  
   194  
   195  /*
   196  ** type for virtual-machine instructions;
   197  ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
   198  */
   199  #if LUAI_IS32INT
   200  typedef unsigned int l_uint32;
   201  #else
   202  typedef unsigned long l_uint32;
   203  #endif
   204  
   205  typedef l_uint32 Instruction;
   206  
   207  
   208  
   209  /*
   210  ** Maximum length for short strings, that is, strings that are
   211  ** internalized. (Cannot be smaller than reserved words or tags for
   212  ** metamethods, as these strings must be internalized;
   213  ** #("function") = 8, #("__newindex") = 10.)
   214  */
   215  #if !defined(LUAI_MAXSHORTLEN)
   216  #define LUAI_MAXSHORTLEN	40
   217  #endif
   218  
   219  
   220  /*
   221  ** Initial size for the string table (must be power of 2).
   222  ** The Lua core alone registers ~50 strings (reserved words +
   223  ** metaevent keys + a few others). Libraries would typically add
   224  ** a few dozens more.
   225  */
   226  #if !defined(MINSTRTABSIZE)
   227  #define MINSTRTABSIZE	128
   228  #endif
   229  
   230  
   231  /*
   232  ** Size of cache for strings in the API. 'N' is the number of
   233  ** sets (better be a prime) and "M" is the size of each set (M == 1
   234  ** makes a direct cache.)
   235  */
   236  #if !defined(STRCACHE_N)
   237  #define STRCACHE_N		53
   238  #define STRCACHE_M		2
   239  #endif
   240  
   241  
   242  /* minimum size for string buffer */
   243  #if !defined(LUA_MINBUFFER)
   244  #define LUA_MINBUFFER	32
   245  #endif
   246  
   247  
   248  /*
   249  ** Maximum depth for nested C calls, syntactical nested non-terminals,
   250  ** and other features implemented through recursion in C. (Value must
   251  ** fit in a 16-bit unsigned integer. It must also be compatible with
   252  ** the size of the C stack.)
   253  */
   254  #if !defined(LUAI_MAXCCALLS)
   255  #define LUAI_MAXCCALLS		200
   256  #endif
   257  
   258  
   259  /*
   260  ** macros that are executed whenever program enters the Lua core
   261  ** ('lua_lock') and leaves the core ('lua_unlock')
   262  */
   263  #if !defined(lua_lock)
   264  #define lua_lock(L)	((void) 0)
   265  #define lua_unlock(L)	((void) 0)
   266  #endif
   267  
   268  /*
   269  ** macro executed during Lua functions at points where the
   270  ** function can yield.
   271  */
   272  #if !defined(luai_threadyield)
   273  #define luai_threadyield(L)	{lua_unlock(L); lua_lock(L);}
   274  #endif
   275  
   276  
   277  /*
   278  ** these macros allow user-specific actions when a thread is
   279  ** created/deleted/resumed/yielded.
   280  */
   281  #if !defined(luai_userstateopen)
   282  #define luai_userstateopen(L)		((void)L)
   283  #endif
   284  
   285  #if !defined(luai_userstateclose)
   286  #define luai_userstateclose(L)		((void)L)
   287  #endif
   288  
   289  #if !defined(luai_userstatethread)
   290  #define luai_userstatethread(L,L1)	((void)L)
   291  #endif
   292  
   293  #if !defined(luai_userstatefree)
   294  #define luai_userstatefree(L,L1)	((void)L)
   295  #endif
   296  
   297  #if !defined(luai_userstateresume)
   298  #define luai_userstateresume(L,n)	((void)L)
   299  #endif
   300  
   301  #if !defined(luai_userstateyield)
   302  #define luai_userstateyield(L,n)	((void)L)
   303  #endif
   304  
   305  
   306  
   307  /*
   308  ** The luai_num* macros define the primitive operations over numbers.
   309  */
   310  
   311  /* floor division (defined as 'floor(a/b)') */
   312  #if !defined(luai_numidiv)
   313  #define luai_numidiv(L,a,b)     ((void)L, l_floor(luai_numdiv(L,a,b)))
   314  #endif
   315  
   316  /* float division */
   317  #if !defined(luai_numdiv)
   318  #define luai_numdiv(L,a,b)      ((a)/(b))
   319  #endif
   320  
   321  /*
   322  ** modulo: defined as 'a - floor(a/b)*b'; the direct computation
   323  ** using this definition has several problems with rounding errors,
   324  ** so it is better to use 'fmod'. 'fmod' gives the result of
   325  ** 'a - trunc(a/b)*b', and therefore must be corrected when
   326  ** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a
   327  ** non-integer negative result: non-integer result is equivalent to
   328  ** a non-zero remainder 'm'; negative result is equivalent to 'a' and
   329  ** 'b' with different signs, or 'm' and 'b' with different signs
   330  ** (as the result 'm' of 'fmod' has the same sign of 'a').
   331  */
   332  #if !defined(luai_nummod)
   333  #define luai_nummod(L,a,b,m)  \
   334    { (void)L; (m) = l_mathop(fmod)(a,b); \
   335      if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); }
   336  #endif
   337  
   338  /* exponentiation */
   339  #if !defined(luai_numpow)
   340  #define luai_numpow(L,a,b)  \
   341    ((void)L, (b == 2) ? (a)*(a) : l_mathop(pow)(a,b))
   342  #endif
   343  
   344  /* the others are quite standard operations */
   345  #if !defined(luai_numadd)
   346  #define luai_numadd(L,a,b)      ((a)+(b))
   347  #define luai_numsub(L,a,b)      ((a)-(b))
   348  #define luai_nummul(L,a,b)      ((a)*(b))
   349  #define luai_numunm(L,a)        (-(a))
   350  #define luai_numeq(a,b)         ((a)==(b))
   351  #define luai_numlt(a,b)         ((a)<(b))
   352  #define luai_numle(a,b)         ((a)<=(b))
   353  #define luai_numgt(a,b)         ((a)>(b))
   354  #define luai_numge(a,b)         ((a)>=(b))
   355  #define luai_numisnan(a)        (!luai_numeq((a), (a)))
   356  #endif
   357  
   358  
   359  
   360  
   361  
   362  /*
   363  ** macro to control inclusion of some hard tests on stack reallocation
   364  */
   365  #if !defined(HARDSTACKTESTS)
   366  #define condmovestack(L,pre,pos)	((void)0)
   367  #else
   368  /* realloc stack keeping its size */
   369  #define condmovestack(L,pre,pos)  \
   370    { int sz_ = stacksize(L); pre; luaD_reallocstack((L), sz_, 0); pos; }
   371  #endif
   372  
   373  #if !defined(HARDMEMTESTS)
   374  #define condchangemem(L,pre,pos)	((void)0)
   375  #else
   376  #define condchangemem(L,pre,pos)  \
   377  	{ if (gcrunning(G(L))) { pre; luaC_fullgc(L, 0); pos; } }
   378  #endif
   379  
   380  #endif