Upgrade to lua 5.4.0.

Test: treehugger
Change-Id: I14a181b5f9633b6d59b2d3f891aa97aa67a1cd21
diff --git a/src/lmem.h b/src/lmem.h
index 357b1e4..8c75a44 100644
--- a/src/lmem.h
+++ b/src/lmem.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.43.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lmem.h $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -14,12 +14,13 @@
 #include "lua.h"
 
 
+#define luaM_error(L)	luaD_throw(L, LUA_ERRMEM)
+
+
 /*
-** 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
@@ -27,43 +28,66 @@
 ** 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)))
+#define luaM_testsize(n,e)  \
+	(sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e))
+
+#define luaM_checksize(L,n,e)  \
+	(luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0))
+
+
+/*
+** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that
+** the result is not larger than 'n' and cannot overflow a 'size_t'
+** when multiplied by the size of type 't'. (Assumes that 'n' is an
+** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.)
+*/
+#define luaM_limitN(n,t)  \
+  ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) :  \
+     cast_uint((MAX_SIZET/sizeof(t))))
+
 
 /*
 ** 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)))
+  cast_charp(luaM_saferealloc_(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_newvector(L,n,t) \
-		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
+#define luaM_new(L,t)		cast(t*, luaM_malloc_(L, sizeof(t), 0))
+#define luaM_newvector(L,n,t)	cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0))
+#define luaM_newvectorchecked(L,n,t) \
+  (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t))
 
-#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), \
+                         luaM_limitN(limit,t),e)))
 
 #define luaM_reallocvector(L, v,oldn,n,t) \
-   ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
+   (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \
+                                  cast_sizet(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_saferealloc_ (lua_State *L, void *block, size_t oldsize,
+                                                              size_t size);
+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