strace/xmalloc.c

/*
 * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
 * Copyright (c) 2015-2017 The strace developers.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdlib.h>
#include <string.h>

#include "error_prints.h"
#include "xmalloc.h"

static void
die_out_of_memory(void)
{
	static int recursed;

	if (recursed)
		exit(1);
	recursed = 1;

	error_msg_and_die("Out of memory");
}

void *
xmalloc(size_t size)
{
	void *p = malloc(size);

	if (!p)
		die_out_of_memory();

	return p;
}

void *
xcalloc(size_t nmemb, size_t size)
{
	void *p = calloc(nmemb, size);

	if (!p)
		die_out_of_memory();

	return p;
}

#define HALF_SIZE_T	(((size_t) 1) << (sizeof(size_t) * 4))

void *
xreallocarray(void *ptr, size_t nmemb, size_t size)
{
	size_t bytes = nmemb * size;

	if ((nmemb | size) >= HALF_SIZE_T &&
	    size && bytes / size != nmemb)
		die_out_of_memory();

	void *p = realloc(ptr, bytes);

	if (!p)
		die_out_of_memory();

	return p;
}

void *
xgrowarray(void *const ptr, size_t *const nmemb, const size_t memb_size)
{
	/* this is the same value as glibc DEFAULT_MXFAST */
	enum { DEFAULT_ALLOC_SIZE = 64 * SIZEOF_LONG / 4 };

	size_t grow_memb;

	if (ptr == NULL)
		grow_memb = *nmemb ? 0 :
			(DEFAULT_ALLOC_SIZE + memb_size - 1) / memb_size;
	else
		grow_memb = (*nmemb >> 1) + 1;

	if ((*nmemb + grow_memb) < *nmemb)
		die_out_of_memory();

	*nmemb += grow_memb;

	return xreallocarray(ptr, *nmemb, memb_size);
}

char *
xstrdup(const char *str)
{
	if (!str)
		return NULL;

	char *p = strdup(str);

	if (!p)
		die_out_of_memory();

	return p;
}

char *
xstrndup(const char *str, size_t n)
{
	char *p;

	if (!str)
		return NULL;

#ifdef HAVE_STRNDUP
	p = strndup(str, n);
#else
	p = xmalloc(n + 1);
#endif

	if (!p)
		die_out_of_memory();

#ifndef HAVE_STRNDUP
	strncpy(p, str, n);
	p[n] = '\0';
#endif

	return p;
}