text: /*
  ** $Id: lmem.h,v 1.43.1.1 2017/04/19 17:20:42 roberto Exp $
  ** Interface to Memory Manager
  ** See Copyright Notice in lua.h
  */
  
  #ifndef lmem_h
  #define lmem_h
  
  
  #include <stddef.h>
  
  #include "llimits.h"
  #include "lua.h"
  
  
  /*
  ** This macro reallocs a vector 'b' from 'on' to 'n' elements, where
  ** each element has size 'e'. In case of arithmetic overflow of the
  ** product 'n'*'e', it raises an error (calling 'luaM_toobig'). Because
  ** 'e' is always constant, it avoids the runtime division MAX_SIZET/(e).
  **
  ** (The macro is somewhat complex to avoid warnings:  The 'sizeof'
  ** comparison avoids a runtime comparison when overflow cannot occur.
  ** The compiler should be able to optimize the real test by itself, but
  ** when it does it, it may give a warning about "comparison is always
  ** false due to limited range of data type"; the +1 tricks the compiler,
  ** avoiding this warning but also this optimization.)
  */
  #define luaM_reallocv(L,b,on,n,e) \
    (((sizeof(n) >= sizeof(size_t) && cast(size_t, (n)) + 1 > MAX_SIZET/(e)) \
        ? luaM_toobig(L) : cast_void(0)) , \
     luaM_realloc_(L, (b), (on)*(e), (n)*(e)))
  
  /*
  ** Arrays of chars do not need any test
  */
  #define luaM_reallocvchar(L,b,on,n)  \
      cast(char *, luaM_realloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
  
  #define luaM_freemem(L, b, s)	luaM_realloc_(L, (b), (s), 0)
  #define luaM_free(L, b)		luaM_realloc_(L, (b), sizeof(*(b)), 0)
  #define luaM_freearray(L, b, n)   luaM_realloc_(L, (b), (n)*sizeof(*(b)), 0)
  
  #define luaM_malloc(L,s)	luaM_realloc_(L, NULL, 0, (s))
  #define luaM_new(L,t)		cast(t *, luaM_malloc(L, sizeof(t)))
  #define luaM_newvector(L,n,t) \
  		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
  
  #define luaM_newobject(L,tag,s)	luaM_realloc_(L, NULL, tag, (s))
  
  #define luaM_growvector(L,v,nelems,size,t,limit,e) \
            if ((nelems)+1 > (size)) \
              ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
  
  #define luaM_reallocvector(L, v,oldn,n,t) \
     ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
  
  LUAI_FUNC l_noret luaM_toobig (lua_State *L);
  
  /* not to be called directly */
  LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
                                                            size_t size);
  LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
                                 size_t size_elem, int limit,
                                 const char *what);
  
  #endif
  
  