Add Lua

third_party/lua/lmem.h

@@ -0,0 +1,93 @@
+/*
+** $Id: lmem.h $
+** 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"
+
+
+#define luaM_error(L)	luaD_throw(L, LUA_ERRMEM)
+
+
+/*
+** 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
+** 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_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_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
+
+#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_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_malloc_(L, (s), tag)
+
+#define luaM_growvector(L,v,nelems,size,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) \
+   (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_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
+