1/*
2** $Id: llimits.h,v 1.141.1.1 2017/04/19 17:20:42 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** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count
19** the total memory used by Lua (in bytes). Usually, 'size_t' and
20** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines.
21*/
22#if defined(LUAI_MEM) /* { external definitions? */
23typedef LUAI_UMEM lu_mem;
24typedef LUAI_MEM l_mem;
25#elif LUAI_BITSINT >= 32 /* }{ */
26typedef size_t lu_mem;
27typedef ptrdiff_t l_mem;
28#else /* 16-bit ints */ /* }{ */
29typedef unsigned long lu_mem;
30typedef long l_mem;
31#endif /* } */
32
33
34/* chars used as small naturals (so that 'char' is reserved for characters) */
35typedef unsigned char lu_byte;
36
37
38/* maximum value for size_t */
39#define MAX_SIZET ((size_t)(~(size_t)0))
40
41/* maximum size visible for Lua (must be representable in a lua_Integer */
42#define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \
43 : (size_t)(LUA_MAXINTEGER))
44
45
46#define MAX_LUMEM ((lu_mem)(~(lu_mem)0))
47
48#define MAX_LMEM ((l_mem)(MAX_LUMEM >> 1))
49
50
51#define MAX_INT INT_MAX /* maximum value of an int */
52
53
54/*
55** conversion of pointer to unsigned integer:
56** this is for hashing only; there is no problem if the integer
57** cannot hold the whole pointer value
58*/
59#define point2uint(p) ((unsigned int)((size_t)(p) & UINT_MAX))
60
61
62
63/* type to ensure maximum alignment */
64#if defined(LUAI_USER_ALIGNMENT_T)
65typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
66#else
67typedef union {
68 lua_Number n;
69 double u;
70 void *s;
71 lua_Integer i;
72 long l;
73} L_Umaxalign;
74#endif
75
76
77
78/* types of 'usual argument conversions' for lua_Number and lua_Integer */
79typedef LUAI_UACNUMBER l_uacNumber;
80typedef LUAI_UACINT l_uacInt;
81
82
83/* internal assertions for in-house debugging */
84#if defined(lua_assert)
85#define check_exp(c,e) (lua_assert(c), (e))
86/* to avoid problems with conditions too long */
87#define lua_longassert(c) ((c) ? (void)0 : lua_assert(0))
88#else
89#define lua_assert(c) ((void)0)
90#define check_exp(c,e) (e)
91#define lua_longassert(c) ((void)0)
92#endif
93
94/*
95** assertion for checking API calls
96*/
97#if !defined(luai_apicheck)
98#define luai_apicheck(l,e) lua_assert(e)
99#endif
100
101#define api_check(l,e,msg) luai_apicheck(l,(e) && msg)
102
103
104/* macro to avoid warnings about unused variables */
105#if !defined(UNUSED)
106#define UNUSED(x) ((void)(x))
107#endif
108
109
110/* type casts (a macro highlights casts in the code) */
111#define cast(t, exp) ((t)(exp))
112
113#define cast_void(i) cast(void, (i))
114#define cast_byte(i) cast(lu_byte, (i))
115#define cast_num(i) cast(lua_Number, (i))
116#define cast_int(i) cast(int, (i))
117#define cast_uchar(i) cast(unsigned char, (i))
118
119
120/* cast a signed lua_Integer to lua_Unsigned */
121#if !defined(l_castS2U)
122#define l_castS2U(i) ((lua_Unsigned)(i))
123#endif
124
125/*
126** cast a lua_Unsigned to a signed lua_Integer; this cast is
127** not strict ISO C, but two-complement architectures should
128** work fine.
129*/
130#if !defined(l_castU2S)
131#define l_castU2S(i) ((lua_Integer)(i))
132#endif
133
134
135/*
136** non-return type
137*/
138#if defined(__GNUC__)
139#define l_noret void __attribute__((noreturn))
140#elif defined(_MSC_VER) && _MSC_VER >= 1200
141#define l_noret void __declspec(noreturn)
142#else
143#define l_noret void
144#endif
145
146
147
148/*
149** maximum depth for nested C calls and syntactical nested non-terminals
150** in a program. (Value must fit in an unsigned short int.)
151*/
152#if !defined(LUAI_MAXCCALLS)
153#define LUAI_MAXCCALLS 200
154#endif
155
156
157
158/*
159** type for virtual-machine instructions;
160** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
161*/
162#if LUAI_BITSINT >= 32
163typedef unsigned int Instruction;
164#else
165typedef unsigned long Instruction;
166#endif
167
168
169
170/*
171** Maximum length for short strings, that is, strings that are
172** internalized. (Cannot be smaller than reserved words or tags for
173** metamethods, as these strings must be internalized;
174** #("function") = 8, #("__newindex") = 10.)
175*/
176#if !defined(LUAI_MAXSHORTLEN)
177#define LUAI_MAXSHORTLEN 40
178#endif
179
180
181/*
182** Initial size for the string table (must be power of 2).
183** The Lua core alone registers ~50 strings (reserved words +
184** metaevent keys + a few others). Libraries would typically add
185** a few dozens more.
186*/
187#if !defined(MINSTRTABSIZE)
188#define MINSTRTABSIZE 128
189#endif
190
191
192/*
193** Size of cache for strings in the API. 'N' is the number of
194** sets (better be a prime) and "M" is the size of each set (M == 1
195** makes a direct cache.)
196*/
197#if !defined(STRCACHE_N)
198#define STRCACHE_N 53
199#define STRCACHE_M 2
200#endif
201
202
203/* minimum size for string buffer */
204#if !defined(LUA_MINBUFFER)
205#define LUA_MINBUFFER 32
206#endif
207
208
209/*
210** macros that are executed whenever program enters the Lua core
211** ('lua_lock') and leaves the core ('lua_unlock')
212*/
213#if !defined(lua_lock)
214#define lua_lock(L) ((void) 0)
215#define lua_unlock(L) ((void) 0)
216#endif
217
218/*
219** macro executed during Lua functions at points where the
220** function can yield.
221*/
222#if !defined(luai_threadyield)
223#define luai_threadyield(L) {lua_unlock(L); lua_lock(L);}
224#endif
225
226
227/*
228** these macros allow user-specific actions on threads when you defined
229** LUAI_EXTRASPACE and need to do something extra when a thread is
230** created/deleted/resumed/yielded.
231*/
232#if !defined(luai_userstateopen)
233#define luai_userstateopen(L) ((void)L)
234#endif
235
236#if !defined(luai_userstateclose)
237#define luai_userstateclose(L) ((void)L)
238#endif
239
240#if !defined(luai_userstatethread)
241#define luai_userstatethread(L,L1) ((void)L)
242#endif
243
244#if !defined(luai_userstatefree)
245#define luai_userstatefree(L,L1) ((void)L)
246#endif
247
248#if !defined(luai_userstateresume)
249#define luai_userstateresume(L,n) ((void)L)
250#endif
251
252#if !defined(luai_userstateyield)
253#define luai_userstateyield(L,n) ((void)L)
254#endif
255
256
257
258/*
259** The luai_num* macros define the primitive operations over numbers.
260*/
261
262/* floor division (defined as 'floor(a/b)') */
263#if !defined(luai_numidiv)
264#define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b)))
265#endif
266
267/* float division */
268#if !defined(luai_numdiv)
269#define luai_numdiv(L,a,b) ((a)/(b))
270#endif
271
272/*
273** modulo: defined as 'a - floor(a/b)*b'; this definition gives NaN when
274** 'b' is huge, but the result should be 'a'. 'fmod' gives the result of
275** 'a - trunc(a/b)*b', and therefore must be corrected when 'trunc(a/b)
276** ~= floor(a/b)'. That happens when the division has a non-integer
277** negative result, which is equivalent to the test below.
278*/
279#if !defined(luai_nummod)
280#define luai_nummod(L,a,b,m) \
281 { (m) = l_mathop(fmod)(a,b); if ((m)*(b) < 0) (m) += (b); }
282#endif
283
284/* exponentiation */
285#if !defined(luai_numpow)
286#define luai_numpow(L,a,b) ((void)L, l_mathop(pow)(a,b))
287#endif
288
289/* the others are quite standard operations */
290#if !defined(luai_numadd)
291#define luai_numadd(L,a,b) ((a)+(b))
292#define luai_numsub(L,a,b) ((a)-(b))
293#define luai_nummul(L,a,b) ((a)*(b))
294#define luai_numunm(L,a) (-(a))
295#define luai_numeq(a,b) ((a)==(b))
296#define luai_numlt(a,b) ((a)<(b))
297#define luai_numle(a,b) ((a)<=(b))
298#define luai_numisnan(a) (!luai_numeq((a), (a)))
299#endif
300
301
302
303
304
305/*
306** macro to control inclusion of some hard tests on stack reallocation
307*/
308#if !defined(HARDSTACKTESTS)
309#define condmovestack(L,pre,pos) ((void)0)
310#else
311/* realloc stack keeping its size */
312#define condmovestack(L,pre,pos) \
313 { int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_); pos; }
314#endif
315
316#if !defined(HARDMEMTESTS)
317#define condchangemem(L,pre,pos) ((void)0)
318#else
319#define condchangemem(L,pre,pos) \
320 { if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } }
321#endif
322
323#endif
324