glibc/include/programs/xmalloc.h
Martin Sebor c1760eaf3b Enable support for GCC 11 -Wmismatched-dealloc.
To help detect common kinds of memory (and other resource) management
bugs, GCC 11 adds support for the detection of mismatched calls to
allocation and deallocation functions.  At each call site to a known
deallocation function GCC checks the set of allocation functions
the former can be paired with and, if the two don't match, issues
a -Wmismatched-dealloc warning (something similar happens in C++
for mismatched calls to new and delete).  GCC also uses the same
mechanism to detect attempts to deallocate objects not allocated
by any allocation function (or pointers past the first byte into
allocated objects) by -Wfree-nonheap-object.

This support is enabled for built-in functions like malloc and free.
To extend it beyond those, GCC extends attribute malloc to designate
a deallocation function to which pointers returned from the allocation
function may be passed to deallocate the allocated objects.  Another,
optional argument designates the positional argument to which
the pointer must be passed.

This change is the first step in enabling this extended support for
Glibc.
2021-05-16 15:21:18 -06:00

34 lines
1.3 KiB
C

/* Memory related definitions for program modules.
Copyright (C) 1998-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <https://www.gnu.org/licenses/>. */
#ifndef _XMALLOC_H
#define _XMALLOC_H 1
#include <sys/cdefs.h>
#include <stddef.h>
/* Prototypes for a few program-wide used functions. */
extern void *xmalloc (size_t n)
__attribute_malloc__ __attribute_alloc_size__ ((1)) __attr_dealloc_free;
extern void *xcalloc (size_t n, size_t s)
__attribute_malloc__ __attribute_alloc_size__ ((1, 2)) __attr_dealloc_free;
extern void *xrealloc (void *o, size_t n)
__attribute_malloc__ __attribute_alloc_size__ ((2)) __attr_dealloc_free;
extern char *xstrdup (const char *) __attribute_malloc__ __attr_dealloc_free;
#endif /* xmalloc.h */