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: |
75 | ** this is for hashing only; there is no problem if the integer |
76 | ** cannot hold the whole pointer value |
77 | */ |
78 | #define point2uint(p) ((unsigned int)((size_t)(p) & UINT_MAX)) |
79 | |
80 | |
81 | |
82 | /* types of 'usual argument conversions' for lua_Number and lua_Integer */ |
83 | typedef LUAI_UACNUMBER l_uacNumber; |
84 | typedef LUAI_UACINT l_uacInt; |
85 | |
86 | |
87 | /* |
88 | ** Internal assertions for in-house debugging |
89 | */ |
90 | #if defined LUAI_ASSERT |
91 | #undef NDEBUG |
92 | #include <assert.h> |
93 | #define lua_assert(c) assert(c) |
94 | #endif |
95 | |
96 | #if defined(lua_assert) |
97 | #define check_exp(c,e) (lua_assert(c), (e)) |
98 | /* to avoid problems with conditions too long */ |
99 | #define lua_longassert(c) ((c) ? (void)0 : lua_assert(0)) |
100 | #else |
101 | #define lua_assert(c) ((void)0) |
102 | #define check_exp(c,e) (e) |
103 | #define lua_longassert(c) ((void)0) |
104 | #endif |
105 | |
106 | /* |
107 | ** assertion for checking API calls |
108 | */ |
109 | #if !defined(luai_apicheck) |
110 | #define luai_apicheck(l,e) ((void)l, lua_assert(e)) |
111 | #endif |
112 | |
113 | #define api_check(l,e,msg) luai_apicheck(l,(e) && msg) |
114 | |
115 | |
116 | /* macro to avoid warnings about unused variables */ |
117 | #if !defined(UNUSED) |
118 | #define UNUSED(x) ((void)(x)) |
119 | #endif |
120 | |
121 | |
122 | /* type casts (a macro highlights casts in the code) */ |
123 | #define cast(t, exp) ((t)(exp)) |
124 | |
125 | #define cast_void(i) cast(void, (i)) |
126 | #define cast_voidp(i) cast(void *, (i)) |
127 | #define cast_num(i) cast(lua_Number, (i)) |
128 | #define cast_int(i) cast(int, (i)) |
129 | #define cast_uint(i) cast(unsigned int, (i)) |
130 | #define cast_byte(i) cast(lu_byte, (i)) |
131 | #define cast_uchar(i) cast(unsigned char, (i)) |
132 | #define cast_char(i) cast(char, (i)) |
133 | #define cast_charp(i) cast(char *, (i)) |
134 | #define cast_sizet(i) cast(size_t, (i)) |
135 | |
136 | |
137 | /* cast a signed lua_Integer to lua_Unsigned */ |
138 | #if !defined(l_castS2U) |
139 | #define l_castS2U(i) ((lua_Unsigned)(i)) |
140 | #endif |
141 | |
142 | /* |
143 | ** cast a lua_Unsigned to a signed lua_Integer; this cast is |
144 | ** not strict ISO C, but two-complement architectures should |
145 | ** work fine. |
146 | */ |
147 | #if !defined(l_castU2S) |
148 | #define l_castU2S(i) ((lua_Integer)(i)) |
149 | #endif |
150 | |
151 | |
152 | /* |
153 | ** macros to improve jump prediction (used mainly for error handling) |
154 | */ |
155 | #if !defined(likely) |
156 | |
157 | #if defined(__GNUC__) |
158 | #define likely(x) (__builtin_expect(((x) != 0), 1)) |
159 | #define unlikely(x) (__builtin_expect(((x) != 0), 0)) |
160 | #else |
161 | #define likely(x) (x) |
162 | #define unlikely(x) (x) |
163 | #endif |
164 | |
165 | #endif |
166 | |
167 | |
168 | /* |
169 | ** non-return type |
170 | */ |
171 | #if !defined(l_noret) |
172 | |
173 | #if defined(__GNUC__) |
174 | #define l_noret void __attribute__((noreturn)) |
175 | #elif defined(_MSC_VER) && _MSC_VER >= 1200 |
176 | #define l_noret void __declspec(noreturn) |
177 | #else |
178 | #define l_noret void |
179 | #endif |
180 | |
181 | #endif |
182 | |
183 | |
184 | /* |
185 | ** type for virtual-machine instructions; |
186 | ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) |
187 | */ |
188 | #if LUAI_IS32INT |
189 | typedef unsigned int l_uint32; |
190 | #else |
191 | typedef unsigned long l_uint32; |
192 | #endif |
193 | |
194 | typedef l_uint32 Instruction; |
195 | |
196 | |
197 | |
198 | /* |
199 | ** Maximum length for short strings, that is, strings that are |
200 | ** internalized. (Cannot be smaller than reserved words or tags for |
201 | ** metamethods, as these strings must be internalized; |
202 | ** #("function") = 8, #("__newindex") = 10.) |
203 | */ |
204 | #if !defined(LUAI_MAXSHORTLEN) |
205 | #define LUAI_MAXSHORTLEN 40 |
206 | #endif |
207 | |
208 | |
209 | /* |
210 | ** Initial size for the string table (must be power of 2). |
211 | ** The Lua core alone registers ~50 strings (reserved words + |
212 | ** metaevent keys + a few others). Libraries would typically add |
213 | ** a few dozens more. |
214 | */ |
215 | #if !defined(MINSTRTABSIZE) |
216 | #define MINSTRTABSIZE 128 |
217 | #endif |
218 | |
219 | |
220 | /* |
221 | ** Size of cache for strings in the API. 'N' is the number of |
222 | ** sets (better be a prime) and "M" is the size of each set (M == 1 |
223 | ** makes a direct cache.) |
224 | */ |
225 | #if !defined(STRCACHE_N) |
226 | #define STRCACHE_N 53 |
227 | #define STRCACHE_M 2 |
228 | #endif |
229 | |
230 | |
231 | /* minimum size for string buffer */ |
232 | #if !defined(LUA_MINBUFFER) |
233 | #define LUA_MINBUFFER 32 |
234 | #endif |
235 | |
236 | |
237 | /* |
238 | ** Maximum depth for nested C calls, syntactical nested non-terminals, |
239 | ** and other features implemented through recursion in C. (Value must |
240 | ** fit in a 16-bit unsigned integer. It must also be compatible with |
241 | ** the size of the C stack.) |
242 | */ |
243 | #if !defined(LUAI_MAXCCALLS) |
244 | #define LUAI_MAXCCALLS 200 |
245 | #endif |
246 | |
247 | |
248 | /* |
249 | ** macros that are executed whenever program enters the Lua core |
250 | ** ('lua_lock') and leaves the core ('lua_unlock') |
251 | */ |
252 | #if !defined(lua_lock) |
253 | #define lua_lock(L) ((void) 0) |
254 | #define lua_unlock(L) ((void) 0) |
255 | #endif |
256 | |
257 | /* |
258 | ** macro executed during Lua functions at points where the |
259 | ** function can yield. |
260 | */ |
261 | #if !defined(luai_threadyield) |
262 | #define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} |
263 | #endif |
264 | |
265 | |
266 | /* |
267 | ** these macros allow user-specific actions when a thread is |
268 | ** created/deleted/resumed/yielded. |
269 | */ |
270 | #if !defined(luai_userstateopen) |
271 | #define luai_userstateopen(L) ((void)L) |
272 | #endif |
273 | |
274 | #if !defined(luai_userstateclose) |
275 | #define luai_userstateclose(L) ((void)L) |
276 | #endif |
277 | |
278 | #if !defined(luai_userstatethread) |
279 | #define luai_userstatethread(L,L1) ((void)L) |
280 | #endif |
281 | |
282 | #if !defined(luai_userstatefree) |
283 | #define luai_userstatefree(L,L1) ((void)L) |
284 | #endif |
285 | |
286 | #if !defined(luai_userstateresume) |
287 | #define luai_userstateresume(L,n) ((void)L) |
288 | #endif |
289 | |
290 | #if !defined(luai_userstateyield) |
291 | #define luai_userstateyield(L,n) ((void)L) |
292 | #endif |
293 | |
294 | |
295 | |
296 | /* |
297 | ** The luai_num* macros define the primitive operations over numbers. |
298 | */ |
299 | |
300 | /* floor division (defined as 'floor(a/b)') */ |
301 | #if !defined(luai_numidiv) |
302 | #define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) |
303 | #endif |
304 | |
305 | /* float division */ |
306 | #if !defined(luai_numdiv) |
307 | #define luai_numdiv(L,a,b) ((a)/(b)) |
308 | #endif |
309 | |
310 | /* |
311 | ** modulo: defined as 'a - floor(a/b)*b'; the direct computation |
312 | ** using this definition has several problems with rounding errors, |
313 | ** so it is better to use 'fmod'. 'fmod' gives the result of |
314 | ** 'a - trunc(a/b)*b', and therefore must be corrected when |
315 | ** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a |
316 | ** non-integer negative result: non-integer result is equivalent to |
317 | ** a non-zero remainder 'm'; negative result is equivalent to 'a' and |
318 | ** 'b' with different signs, or 'm' and 'b' with different signs |
319 | ** (as the result 'm' of 'fmod' has the same sign of 'a'). |
320 | */ |
321 | #if !defined(luai_nummod) |
322 | #define luai_nummod(L,a,b,m) \ |
323 | { (void)L; (m) = l_mathop(fmod)(a,b); \ |
324 | if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); } |
325 | #endif |
326 | |
327 | /* exponentiation */ |
328 | #if !defined(luai_numpow) |
329 | #define luai_numpow(L,a,b) ((void)L, l_mathop(pow)(a,b)) |
330 | #endif |
331 | |
332 | /* the others are quite standard operations */ |
333 | #if !defined(luai_numadd) |
334 | #define luai_numadd(L,a,b) ((a)+(b)) |
335 | #define luai_numsub(L,a,b) ((a)-(b)) |
336 | #define luai_nummul(L,a,b) ((a)*(b)) |
337 | #define luai_numunm(L,a) (-(a)) |
338 | #define luai_numeq(a,b) ((a)==(b)) |
339 | #define luai_numlt(a,b) ((a)<(b)) |
340 | #define luai_numle(a,b) ((a)<=(b)) |
341 | #define luai_numgt(a,b) ((a)>(b)) |
342 | #define luai_numge(a,b) ((a)>=(b)) |
343 | #define luai_numisnan(a) (!luai_numeq((a), (a))) |
344 | #endif |
345 | |
346 | |
347 | |
348 | |
349 | |
350 | /* |
351 | ** macro to control inclusion of some hard tests on stack reallocation |
352 | */ |
353 | #if !defined(HARDSTACKTESTS) |
354 | #define condmovestack(L,pre,pos) ((void)0) |
355 | #else |
356 | /* realloc stack keeping its size */ |
357 | #define condmovestack(L,pre,pos) \ |
358 | { int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_, 0); pos; } |
359 | #endif |
360 | |
361 | #if !defined(HARDMEMTESTS) |
362 | #define condchangemem(L,pre,pos) ((void)0) |
363 | #else |
364 | #define condchangemem(L,pre,pos) \ |
365 | { if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } } |
366 | #endif |
367 | |
368 | #endif |
369 | |