avoid using one function for different tasks (malloc, free, etc.)

lmem.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.42 2014/12/19 13:45:40 roberto Exp roberto $
+** $Id: lmem.h,v 1.43 2014/12/19 17:26:14 roberto Exp roberto $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -15,11 +15,9 @@
 
 
 /*
-** 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).
-**
+** This macro tests whether it is safe to multiply 'n' by the size of
+** type 't' without overflows. 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
@@ -27,10 +25,20 @@
 ** false due to limited range of data type"; the +1 tricks the compiler,
 ** avoiding this warning but also this optimization.)
 */
+#define luaM_testsize(n,e)  \
+	(sizeof(n) >= sizeof(size_t) && cast(size_t, (n)) + 1 > MAX_SIZET/(e))
+
+#define luaM_checksize(L,n,e)  \
+	(luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0))
+
+/*
+** 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').
+*/
 #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)))
+  (luaM_checksize(L,n,e), \
+   luaM_realloc_(L, (b), cast(size_t, on)*(e), cast(size_t, n)*(e)))
 
 /*
 ** Arrays of chars do not need any test
@@ -38,32 +46,37 @@
 #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_freemem(L, b, s)	luaM_free_(L, (b), (s))
+#define luaM_free(L, b)		luaM_free_(L, (b), sizeof(*(b)))
+#define luaM_freearray(L, b, n)   luaM_free_(L, (b), (n)*sizeof(*(b)))
 
-#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_new(L,t)		cast(t *, luaM_malloc(L, sizeof(t), 0))
 #define luaM_newvector(L,n,t) \
-		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
+  (luaM_checksize(L,n,sizeof(t)), cast(t *, luaM_malloc(L, (n)*sizeof(t), 0)))
 
-#define luaM_newobject(L,tag,s)	luaM_realloc_(L, NULL, tag, (s))
+#define luaM_newobject(L,tag,s)	luaM_malloc(L, (s), tag)
 
 #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)))
+	((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t),limit,e)))
 
 #define luaM_reallocvector(L, v,oldn,n,t) \
    ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
 
+#define luaM_shrinkvector(L,v,size,fs,t) \
+   ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, 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,
+LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize);
+LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems,
+                               int *size, int size_elem, int limit,
                                const char *what);
+LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem,
+                                    int final_n, int size_elem);
+LUAI_FUNC void *luaM_malloc (lua_State *L, size_t size, int tag);
 
 #endif