Systemd/src/basic/alloc-util.h
Lennart Poettering c165d97d16 alloc-util: add new helpers memdup_suffix0() and newdup_suffix0()
These are similar to memdup() and newdup(), but reserve one extra NUL
byte at the end of the new allocation and initialize it. It's useful
when copying out data from fixed size character arrays where NUL
termination can't be assumed.
2017-07-31 18:20:28 +02:00

130 lines
4.6 KiB
C

#pragma once
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <alloca.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "macro.h"
#define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
#define new0(t, n) ((t*) calloc((n), sizeof(t)))
#define newa(t, n) ((t*) alloca(sizeof(t)*(n)))
#define newa0(t, n) ((t*) alloca0(sizeof(t)*(n)))
#define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
#define newdup_suffix0(t, p, n) ((t*) memdup_suffix0_multiply(p, sizeof(t), (n)))
#define malloc0(n) (calloc(1, (n)))
static inline void *mfree(void *memory) {
free(memory);
return NULL;
}
#define free_and_replace(a, b) \
({ \
free(a); \
(a) = (b); \
(b) = NULL; \
0; \
})
void* memdup(const void *p, size_t l) _alloc_(2);
void* memdup_suffix0(const void*p, size_t l) _alloc_(2);
static inline void freep(void *p) {
free(*(void**) p);
}
#define _cleanup_free_ _cleanup_(freep)
static inline bool size_multiply_overflow(size_t size, size_t need) {
return _unlikely_(need != 0 && size > (SIZE_MAX / need));
}
_malloc_ _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return malloc(size * need);
}
_alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return realloc(p, size * need);
}
_alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return memdup(p, size * need);
}
_alloc_(2, 3) static inline void *memdup_suffix0_multiply(const void *p, size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return memdup_suffix0(p, size * need);
}
void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
#define GREEDY_REALLOC(array, allocated, need) \
greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
#define GREEDY_REALLOC0(array, allocated, need) \
greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
#define alloca0(n) \
({ \
char *_new_; \
size_t _len_ = n; \
_new_ = alloca(_len_); \
(void *) memset(_new_, 0, _len_); \
})
/* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
#define alloca_align(size, align) \
({ \
void *_ptr_; \
size_t _mask_ = (align) - 1; \
_ptr_ = alloca((size) + _mask_); \
(void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_); \
})
#define alloca0_align(size, align) \
({ \
void *_new_; \
size_t _size_ = (size); \
_new_ = alloca_align(_size_, (align)); \
(void*)memset(_new_, 0, _size_); \
})