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