1 /* $NetBSD: lmem.h,v 1.9 2023/04/16 20:46:17 nikita Exp $ */ 2 3 /* 4 ** Id: lmem.h 5 ** Interface to Memory Manager 6 ** See Copyright Notice in lua.h 7 */ 8 9 #ifndef lmem_h 10 #define lmem_h 11 12 13 #ifndef _KERNEL 14 #include <stddef.h> 15 #endif /* _KERNEL */ 16 17 #include "llimits.h" 18 #include "lua.h" 19 20 21 #define luaM_error(L) luaD_throw(L, LUA_ERRMEM) 22 23 24 /* 25 ** This macro tests whether it is safe to multiply 'n' by the size of 26 ** type 't' without overflows. Because 'e' is always constant, it avoids 27 ** the runtime division MAX_SIZET/(e). 28 ** (The macro is somewhat complex to avoid warnings: The 'sizeof' 29 ** comparison avoids a runtime comparison when overflow cannot occur. 30 ** The compiler should be able to optimize the real test by itself, but 31 ** when it does it, it may give a warning about "comparison is always 32 ** false due to limited range of data type"; the +1 tricks the compiler, 33 ** avoiding this warning but also this optimization.) 34 */ 35 #define luaM_testsize(n,e) \ 36 (sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e)) 37 38 #define luaM_checksize(L,n,e) \ 39 (luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0)) 40 41 42 /* 43 ** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that 44 ** the result is not larger than 'n' and cannot overflow a 'size_t' 45 ** when multiplied by the size of type 't'. (Assumes that 'n' is an 46 ** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.) 47 */ 48 #define luaM_limitN(n,t) \ 49 ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) : \ 50 cast_uint((MAX_SIZET/sizeof(t)))) 51 52 53 /* 54 ** Arrays of chars do not need any test 55 */ 56 #define luaM_reallocvchar(L,b,on,n) \ 57 cast_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char))) 58 59 #define luaM_freemem(L, b, s) luaM_free_(L, (b), (s)) 60 #define luaM_free(L, b) luaM_free_(L, (b), sizeof(*(b))) 61 #define luaM_freearray(L, b, n) luaM_free_(L, (b), (n)*sizeof(*(b))) 62 63 #define luaM_new(L,t) cast(t*, luaM_malloc_(L, sizeof(t), 0)) 64 #define luaM_newvector(L,n,t) cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0)) 65 #define luaM_newvectorchecked(L,n,t) \ 66 (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t)) 67 68 #define luaM_newobject(L,tag,s) luaM_malloc_(L, (s), tag) 69 70 #define luaM_growvector(L,v,nelems,size,t,limit,e) \ 71 ((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t), \ 72 luaM_limitN(limit,t),e))) 73 74 #define luaM_reallocvector(L, v,oldn,n,t) \ 75 (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \ 76 cast_sizet(n) * sizeof(t)))) 77 78 #define luaM_shrinkvector(L,v,size,fs,t) \ 79 ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, sizeof(t)))) 80 81 LUAI_FUNC l_noret luaM_toobig (lua_State *L); 82 83 /* not to be called directly */ 84 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize, 85 size_t size); 86 LUAI_FUNC void *luaM_saferealloc_ (lua_State *L, void *block, size_t oldsize, 87 size_t size); 88 LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize); 89 LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems, 90 int *size, int size_elem, int limit, 91 const char *what); 92 LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem, 93 int final_n, int size_elem); 94 LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag); 95 96 #endif 97 98