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? */
 24typedef LUAI_UMEM lu_mem;
 25typedef LUAI_MEM l_mem;
 26#elif LUAI_IS32INT	/* }{ */
 27typedef size_t lu_mem;
 28typedef ptrdiff_t l_mem;
 29#else  /* 16-bit ints */	/* }{ */
 30typedef unsigned long lu_mem;
 31typedef long l_mem;
 32#endif				/* } */
 33
 34
 35/* chars used as small naturals (so that 'char' is reserved for characters) */
 36typedef unsigned char lu_byte;
 37typedef 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 */
 96typedef LUAI_UACNUMBER l_uacNumber;
 97typedef 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
200typedef unsigned int l_uint32;
201#else
202typedef unsigned long l_uint32;
203#endif
204
205typedef 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