Systemd/src/basic/alloc-util.h

142 lines
5.1 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#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);
}
#if !HAVE_REALLOCARRAY
_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
if (size_multiply_overflow(size, need))
return NULL;
return realloc(p, size * need);
}
#endif
_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_); \
})
/* Takes inspiration from Rusts's Option::take() method: reads and returns a pointer, but at the same time resets it to
* NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
#define TAKE_PTR(ptr) \
({ \
typeof(ptr) _ptr_ = (ptr); \
(ptr) = NULL; \
_ptr_; \
})