liblua/lmem.h

   1 /*
   2 ** $Id: lmem.h,v 1.40 2013/02/20 14:08:21 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 avoids the runtime division MAX_SIZET/(e), as 'e' is
  19 ** always constant.
  20 ** The macro is somewhat complex to avoid warnings:
  21 ** +1 avoids warnings of "comparison has constant result";
  22 ** cast to 'void' avoids warnings of "value unused".
  23 */
  24 #define luaM_reallocv(L,b,on,n,e) \
  25   (cast(void, \
  26      (cast(size_t, (n)+1) > MAX_SIZET/(e)) ? (luaM_toobig(L), 0) : 0), \
  27    luaM_realloc_(L, (b), (on)*(e), (n)*(e)))
  28
  29 #define luaM_freemem(L, b, s)   luaM_realloc_(L, (b), (s), 0)
  30 #define luaM_free(L, b)         luaM_realloc_(L, (b), sizeof(*(b)), 0)
  31 #define luaM_freearray(L, b, n)   luaM_reallocv(L, (b), n, 0, sizeof((b)[0]))
  32
  33 #define luaM_malloc(L,s)        luaM_realloc_(L, NULL, 0, (s))
  34 #define luaM_new(L,t)           cast(t *, luaM_malloc(L, sizeof(t)))
  35 #define luaM_newvector(L,n,t) \
  36                 cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
  37
  38 #define luaM_newobject(L,tag,s) luaM_realloc_(L, NULL, tag, (s))
  39
  40 #define luaM_growvector(L,v,nelems,size,t,limit,e) \
  41           if ((nelems)+1 > (size)) \
  42             ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
  43
  44 #define luaM_reallocvector(L, v,oldn,n,t) \
  45    ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
  46
  47 LUAI_FUNC l_noret luaM_toobig (lua_State *L);
  48
  49 /* not to be called directly */
  50 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
  51                                                           size_t size);
  52 LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
  53                                size_t size_elem, int limit,
  54                                const char *what);
  55
  56 #endif
  57