1 /*
2 * Copyright (c) 2014-2019 Pavel Kalvoda <me@pavelkalvoda.com>
3 *
4 * libcbor is free software; you can redistribute it and/or modify
5 * it under the terms of the MIT license. See LICENSE for details.
6 */
7
8 #include "memory_utils.h"
9 #include "cbor/common.h"
10
11 // TODO: Consider builtins
12 // (https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html)
13
14 /** Highest on bit position */
_cbor_highest_bit(size_t number)15 size_t _cbor_highest_bit(size_t number) {
16 size_t bit = 0;
17 while (number != 0) {
18 bit++;
19 number >>= 1;
20 }
21
22 return bit;
23 }
24
_cbor_safe_to_multiply(size_t a,size_t b)25 bool _cbor_safe_to_multiply(size_t a, size_t b) {
26 return _cbor_highest_bit(a) + _cbor_highest_bit(b) <= sizeof(size_t) * 8;
27 }
28
_cbor_alloc_multiple(size_t item_size,size_t item_count)29 void* _cbor_alloc_multiple(size_t item_size, size_t item_count) {
30 if (_cbor_safe_to_multiply(item_size, item_count)) {
31 return _CBOR_MALLOC(item_size * item_count);
32 } else {
33 return NULL;
34 }
35 }
36
_cbor_realloc_multiple(void * pointer,size_t item_size,size_t item_count)37 void* _cbor_realloc_multiple(void* pointer, size_t item_size,
38 size_t item_count) {
39 if (_cbor_safe_to_multiply(item_size, item_count)) {
40 return _CBOR_REALLOC(pointer, item_size * item_count);
41 } else {
42 return NULL;
43 }
44 }
45