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1 /*
2 ** $Id: llimits.h,v 1.103.1.1 2013/04/12 18:48:47 roberto Exp $
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 typedef unsigned LUA_INT32 lu_int32;
19 
20 typedef LUAI_UMEM lu_mem;
21 
22 typedef LUAI_MEM l_mem;
23 
24 
25 
26 /* chars used as small naturals (so that `char' is reserved for characters) */
27 typedef unsigned char lu_byte;
28 
29 
30 #define MAX_SIZET	((size_t)(~(size_t)0)-2)
31 
32 #define MAX_LUMEM	((lu_mem)(~(lu_mem)0)-2)
33 
34 #define MAX_LMEM	((l_mem) ((MAX_LUMEM >> 1) - 2))
35 
36 
37 #define MAX_INT (INT_MAX-2)  /* maximum value of an int (-2 for safety) */
38 
39 /*
40 ** conversion of pointer to integer
41 ** this is for hashing only; there is no problem if the integer
42 ** cannot hold the whole pointer value
43 */
44 #define IntPoint(p)  ((unsigned int)(lu_mem)(p))
45 
46 
47 
48 /* type to ensure maximum alignment */
49 #if !defined(LUAI_USER_ALIGNMENT_T)
50 #define LUAI_USER_ALIGNMENT_T	union { double u; void *s; long l; }
51 #endif
52 
53 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
54 
55 
56 /* result of a `usual argument conversion' over lua_Number */
57 typedef LUAI_UACNUMBER l_uacNumber;
58 
59 
60 /* internal assertions for in-house debugging */
61 #if defined(lua_assert)
62 #define check_exp(c,e)		(lua_assert(c), (e))
63 /* to avoid problems with conditions too long */
64 #define lua_longassert(c)	{ if (!(c)) lua_assert(0); }
65 #else
66 #define lua_assert(c)		((void)0)
67 #define check_exp(c,e)		(e)
68 #define lua_longassert(c)	((void)0)
69 #endif
70 
71 /*
72 ** assertion for checking API calls
73 */
74 #if !defined(luai_apicheck)
75 
76 #if defined(LUA_USE_APICHECK)
77 #include <assert.h>
78 #define luai_apicheck(L,e)	assert(e)
79 #else
80 #define luai_apicheck(L,e)	lua_assert(e)
81 #endif
82 
83 #endif
84 
85 #define api_check(l,e,msg)	luai_apicheck(l,(e) && msg)
86 
87 
88 #if !defined(UNUSED)
89 #define UNUSED(x)	((void)(x))	/* to avoid warnings */
90 #endif
91 
92 
93 #define cast(t, exp)	((t)(exp))
94 
95 #define cast_byte(i)	cast(lu_byte, (i))
96 #define cast_num(i)	cast(lua_Number, (i))
97 #define cast_int(i)	cast(int, (i))
98 #define cast_uchar(i)	cast(unsigned char, (i))
99 
100 
101 /*
102 ** non-return type
103 */
104 #if defined(__GNUC__)
105 #define l_noret		void __attribute__((noreturn))
106 #elif defined(_MSC_VER)
107 #define l_noret		void __declspec(noreturn)
108 #else
109 #define l_noret		void
110 #endif
111 
112 
113 
114 /*
115 ** maximum depth for nested C calls and syntactical nested non-terminals
116 ** in a program. (Value must fit in an unsigned short int.)
117 */
118 #if !defined(LUAI_MAXCCALLS)
119 #define LUAI_MAXCCALLS		200
120 #endif
121 
122 /*
123 ** maximum number of upvalues in a closure (both C and Lua). (Value
124 ** must fit in an unsigned char.)
125 */
126 #define MAXUPVAL	UCHAR_MAX
127 
128 
129 /*
130 ** type for virtual-machine instructions
131 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
132 */
133 typedef lu_int32 Instruction;
134 
135 
136 
137 /* maximum stack for a Lua function */
138 #define MAXSTACK	250
139 
140 
141 
142 /* minimum size for the string table (must be power of 2) */
143 #if !defined(MINSTRTABSIZE)
144 #define MINSTRTABSIZE	32
145 #endif
146 
147 
148 /* minimum size for string buffer */
149 #if !defined(LUA_MINBUFFER)
150 #define LUA_MINBUFFER	32
151 #endif
152 
153 
154 #if !defined(lua_lock)
155 #define lua_lock(L)     ((void) 0)
156 #define lua_unlock(L)   ((void) 0)
157 #endif
158 
159 #if !defined(luai_threadyield)
160 #define luai_threadyield(L)     {lua_unlock(L); lua_lock(L);}
161 #endif
162 
163 
164 /*
165 ** these macros allow user-specific actions on threads when you defined
166 ** LUAI_EXTRASPACE and need to do something extra when a thread is
167 ** created/deleted/resumed/yielded.
168 */
169 #if !defined(luai_userstateopen)
170 #define luai_userstateopen(L)		((void)L)
171 #endif
172 
173 #if !defined(luai_userstateclose)
174 #define luai_userstateclose(L)		((void)L)
175 #endif
176 
177 #if !defined(luai_userstatethread)
178 #define luai_userstatethread(L,L1)	((void)L)
179 #endif
180 
181 #if !defined(luai_userstatefree)
182 #define luai_userstatefree(L,L1)	((void)L)
183 #endif
184 
185 #if !defined(luai_userstateresume)
186 #define luai_userstateresume(L,n)       ((void)L)
187 #endif
188 
189 #if !defined(luai_userstateyield)
190 #define luai_userstateyield(L,n)        ((void)L)
191 #endif
192 
193 /*
194 ** lua_number2int is a macro to convert lua_Number to int.
195 ** lua_number2integer is a macro to convert lua_Number to lua_Integer.
196 ** lua_number2unsigned is a macro to convert a lua_Number to a lua_Unsigned.
197 ** lua_unsigned2number is a macro to convert a lua_Unsigned to a lua_Number.
198 ** luai_hashnum is a macro to hash a lua_Number value into an integer.
199 ** The hash must be deterministic and give reasonable values for
200 ** both small and large values (outside the range of integers).
201 */
202 
203 #if defined(MS_ASMTRICK) || defined(LUA_MSASMTRICK)	/* { */
204 /* trick with Microsoft assembler for X86 */
205 
206 #define lua_number2int(i,n)  __asm {__asm fld n   __asm fistp i}
207 #define lua_number2integer(i,n)		lua_number2int(i, n)
208 #define lua_number2unsigned(i,n)  \
209   {__int64 l; __asm {__asm fld n   __asm fistp l} i = (unsigned int)l;}
210 
211 
212 #elif defined(LUA_IEEE754TRICK)		/* }{ */
213 /* the next trick should work on any machine using IEEE754 with
214    a 32-bit int type */
215 
216 union luai_Cast { double l_d; LUA_INT32 l_p[2]; };
217 
218 #if !defined(LUA_IEEEENDIAN)	/* { */
219 #define LUAI_EXTRAIEEE	\
220   static const union luai_Cast ieeeendian = {-(33.0 + 6755399441055744.0)};
221 #define LUA_IEEEENDIANLOC	(ieeeendian.l_p[1] == 33)
222 #else
223 #define LUA_IEEEENDIANLOC	LUA_IEEEENDIAN
224 #define LUAI_EXTRAIEEE		/* empty */
225 #endif				/* } */
226 
227 #define lua_number2int32(i,n,t) \
228   { LUAI_EXTRAIEEE \
229     volatile union luai_Cast u; u.l_d = (n) + 6755399441055744.0; \
230     (i) = (t)u.l_p[LUA_IEEEENDIANLOC]; }
231 
232 #define luai_hashnum(i,n)  \
233   { volatile union luai_Cast u; u.l_d = (n) + 1.0;  /* avoid -0 */ \
234     (i) = u.l_p[0]; (i) += u.l_p[1]; }  /* add double bits for his hash */
235 
236 #define lua_number2int(i,n)		lua_number2int32(i, n, int)
237 #define lua_number2unsigned(i,n)	lua_number2int32(i, n, lua_Unsigned)
238 
239 /* the trick can be expanded to lua_Integer when it is a 32-bit value */
240 #if defined(LUA_IEEELL)
241 #define lua_number2integer(i,n)		lua_number2int32(i, n, lua_Integer)
242 #endif
243 
244 #endif				/* } */
245 
246 
247 /* the following definitions always work, but may be slow */
248 
249 #if !defined(lua_number2int)
250 #define lua_number2int(i,n)	((i)=(int)(n))
251 #endif
252 
253 #if !defined(lua_number2integer)
254 #define lua_number2integer(i,n)	((i)=(lua_Integer)(n))
255 #endif
256 
257 #if !defined(lua_number2unsigned)	/* { */
258 /* the following definition assures proper modulo behavior */
259 #if defined(LUA_NUMBER_DOUBLE) || defined(LUA_NUMBER_FLOAT)
260 #include <math.h>
261 #define SUPUNSIGNED	((lua_Number)(~(lua_Unsigned)0) + 1)
262 #define lua_number2unsigned(i,n)  \
263 	((i)=(lua_Unsigned)((n) - floor((n)/SUPUNSIGNED)*SUPUNSIGNED))
264 #else
265 #define lua_number2unsigned(i,n)	((i)=(lua_Unsigned)(n))
266 #endif
267 #endif				/* } */
268 
269 
270 #if !defined(lua_unsigned2number)
271 /* on several machines, coercion from unsigned to double is slow,
272    so it may be worth to avoid */
273 #define lua_unsigned2number(u)  \
274     (((u) <= (lua_Unsigned)INT_MAX) ? (lua_Number)(int)(u) : (lua_Number)(u))
275 #endif
276 
277 
278 
279 #if defined(ltable_c) && !defined(luai_hashnum)
280 
281 #include <float.h>
282 #include <math.h>
283 
284 #define luai_hashnum(i,n) { int e;  \
285   n = l_mathop(frexp)(n, &e) * (lua_Number)(INT_MAX - DBL_MAX_EXP);  \
286   lua_number2int(i, n); i += e; }
287 
288 #endif
289 
290 
291 
292 /*
293 ** macro to control inclusion of some hard tests on stack reallocation
294 */
295 #if !defined(HARDSTACKTESTS)
296 #define condmovestack(L)	((void)0)
297 #else
298 /* realloc stack keeping its size */
299 #define condmovestack(L)	luaD_reallocstack((L), (L)->stacksize)
300 #endif
301 
302 #if !defined(HARDMEMTESTS)
303 #define condchangemem(L)	condmovestack(L)
304 #else
305 #define condchangemem(L)  \
306 	((void)(!(G(L)->gcrunning) || (luaC_fullgc(L, 0), 1)))
307 #endif
308 
309 #endif
310