1/* 2** $Id: lmem.h $ 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#define luaM_error(L) luaD_throw(L, LUA_ERRMEM) 18 19 20/* 21** This macro tests whether it is safe to multiply 'n' by the size of 22** type 't' without overflows. Because 'e' is always constant, it avoids 23** the runtime division MAX_SIZET/(e). 24** (The macro is somewhat complex to avoid warnings: The 'sizeof' 25** comparison avoids a runtime comparison when overflow cannot occur. 26** The compiler should be able to optimize the real test by itself, but 27** when it does it, it may give a warning about "comparison is always 28** false due to limited range of data type"; the +1 tricks the compiler, 29** avoiding this warning but also this optimization.) 30*/ 31#define luaM_testsize(n,e) \ 32 (sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e)) 33 34#define luaM_checksize(L,n,e) \ 35 (luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0)) 36 37 38/* 39** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that 40** the result is not larger than 'n' and cannot overflow a 'size_t' 41** when multiplied by the size of type 't'. (Assumes that 'n' is an 42** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.) 43*/ 44#define luaM_limitN(n,t) \ 45 ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) : \ 46 cast_uint((MAX_SIZET/sizeof(t)))) 47 48 49/* 50** Arrays of chars do not need any test 51*/ 52#define luaM_reallocvchar(L,b,on,n) \ 53 cast_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char))) 54 55#define luaM_freemem(L, b, s) luaM_free_(L, (b), (s)) 56#define luaM_free(L, b) luaM_free_(L, (b), sizeof(*(b))) 57#define luaM_freearray(L, b, n) luaM_free_(L, (b), (n)*sizeof(*(b))) 58 59#define luaM_new(L,t) cast(t*, luaM_malloc_(L, sizeof(t), 0)) 60#define luaM_newvector(L,n,t) cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0)) 61#define luaM_newvectorchecked(L,n,t) \ 62 (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t)) 63 64#define luaM_newobject(L,tag,s) luaM_malloc_(L, (s), tag) 65 66#define luaM_growvector(L,v,nelems,size,t,limit,e) \ 67 ((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t), \ 68 luaM_limitN(limit,t),e))) 69 70#define luaM_reallocvector(L, v,oldn,n,t) \ 71 (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \ 72 cast_sizet(n) * sizeof(t)))) 73 74#define luaM_shrinkvector(L,v,size,fs,t) \ 75 ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, sizeof(t)))) 76 77LUAI_FUNC l_noret luaM_toobig (lua_State *L); 78 79/* not to be called directly */ 80LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize, 81 size_t size); 82LUAI_FUNC void *luaM_saferealloc_ (lua_State *L, void *block, size_t oldsize, 83 size_t size); 84LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize); 85LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems, 86 int *size, int size_elem, int limit, 87 const char *what); 88LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem, 89 int final_n, int size_elem); 90LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag); 91 92#endif 93 94