The Battle for Wesnoth  1.15.2+dev
lmem.h
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1 /*
2 ** $Id: lmem.h,v 1.43.1.1 2017/04/19 17:20:42 roberto Exp $
3 ** Interface to Memory Manager
4 ** See Copyright Notice in lua.h
5 */
6 
7 #ifndef lmem_h
8 #define lmem_h
9 
10 
11 #include <stddef.h>
12 
13 #include "llimits.h"
14 #include "lua.h"
15 
16 
17 /*
18 ** This macro reallocs a vector 'b' from 'on' to 'n' elements, where
19 ** each element has size 'e'. In case of arithmetic overflow of the
20 ** product 'n'*'e', it raises an error (calling 'luaM_toobig'). Because
21 ** 'e' is always constant, it avoids the runtime division MAX_SIZET/(e).
22 **
23 ** (The macro is somewhat complex to avoid warnings: The 'sizeof'
24 ** comparison avoids a runtime comparison when overflow cannot occur.
25 ** The compiler should be able to optimize the real test by itself, but
26 ** when it does it, it may give a warning about "comparison is always
27 ** false due to limited range of data type"; the +1 tricks the compiler,
28 ** avoiding this warning but also this optimization.)
29 */
30 #define luaM_reallocv(L,b,on,n,e) \
31  (((sizeof(n) >= sizeof(size_t) && cast(size_t, (n)) + 1 > MAX_SIZET/(e)) \
32  ? luaM_toobig(L) : cast_void(0)) , \
33  luaM_realloc_(L, (b), (on)*(e), (n)*(e)))
34 
35 /*
36 ** Arrays of chars do not need any test
37 */
38 #define luaM_reallocvchar(L,b,on,n) \
39  cast(char *, luaM_realloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
40 
41 #define luaM_freemem(L, b, s) luaM_realloc_(L, (b), (s), 0)
42 #define luaM_free(L, b) luaM_realloc_(L, (b), sizeof(*(b)), 0)
43 #define luaM_freearray(L, b, n) luaM_realloc_(L, (b), (n)*sizeof(*(b)), 0)
44 
45 #define luaM_malloc(L,s) luaM_realloc_(L, NULL, 0, (s))
46 #define luaM_new(L,t) cast(t *, luaM_malloc(L, sizeof(t)))
47 #define luaM_newvector(L,n,t) \
48  cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
49 
50 #define luaM_newobject(L,tag,s) luaM_realloc_(L, NULL, tag, (s))
51 
52 #define luaM_growvector(L,v,nelems,size,t,limit,e) \
53  if ((nelems)+1 > (size)) \
54  ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
55 
56 #define luaM_reallocvector(L, v,oldn,n,t) \
57  ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
58 
60 
61 /* not to be called directly */
62 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
63  size_t size);
64 LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
65  size_t size_elem, int limit,
66  const char *what);
67 
68 #endif
69 
#define LUAI_FUNC
Definition: luaconf.h:282
#define l_noret
Definition: llimits.h:143
std::size_t size(const std::string &str)
Length in characters of a UTF-8 string.
Definition: unicode.cpp:86
LUAI_FUNC void * luaM_realloc_(lua_State *L, void *block, size_t oldsize, size_t size)
Definition: lmem.cpp:77
static void block(LexState *ls)
Definition: lparser.cpp:1093
LUAI_FUNC void * luaM_growaux_(lua_State *L, void *block, int *size, size_t size_elem, int limit, const char *what)
Definition: lmem.cpp:48
LUAI_FUNC l_noret luaM_toobig(lua_State *L)
Definition: lmem.cpp:68