Add reallocf function

Makefile

@@ -33,6 +33,7 @@ LIB_SRCS := \
 	hash/md5.c \
 	pidfile.c \
 	readpassphrase.c \
+	reallocf.c \
 	setmode.c \
 	setproctitle.c \
 	strmode.c \
@@ -84,6 +85,7 @@ LIB_MANS := \
 	fgetln.3 \
 	flopen.3 \
 	readpassphrase.3 \
+	reallocf.3 \
 	humanize_number.3 \
 	fmtcheck.3 \
 	nlist.3 \

Versions

@@ -65,3 +65,7 @@ LIBBSD_0.2 {
     arc4random_uniform;
 } LIBBSD_0.1;
 
+LIBBSD_0.3 {
+    reallocf;
+} LIBBSD_0.2;
+

include/bsd/stdlib.h

@@ -53,6 +53,8 @@ void setprogname(const char *);
 
 int heapsort (void *, size_t, size_t, int (*)(const void *, const void *));
 
+void *reallocf(void *ptr, size_t size);
+
 long long strtonum(const char *nptr, long long minval, long long maxval,
                    const char **errstr);
 __END_DECLS

src/reallocf.3

@@ -0,0 +1,107 @@
+.\" Copyright (c) 1980, 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" the American National Standards Committee X3, on Information
+.\" Processing Systems.
+.\"
+.\" 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. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
+.\"
+.\"     @(#)malloc.3	8.1 (Berkeley) 6/4/93
+.\" $FreeBSD: src/lib/libc/stdlib/malloc.3,v 1.80.2.2.2.1 2010/06/14 02:09:06 kensmith Exp $
+.\"
+.Dd September 26, 2009
+.Dt MALLOC 3
+.Os
+.Sh NAME
+.Nm reallocf
+.Nd general purpose memory allocation functions
+.Sh LIBRARY
+.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
+.Lb libbsd
+.Sh SYNOPSIS
+.In stdlib.h
+.Ft void *
+.Fn reallocf "void *ptr" "size_t size"
+.Sh DESCRIPTION
+The
+.Fn reallocf
+function changes the size of the previously allocated memory referenced by
+.Fa ptr
+to
+.Fa size
+bytes.
+The contents of the memory are unchanged up to the lesser of the new and
+old sizes.
+If the new size is larger,
+the contents of the newly allocated portion of the memory are undefined.
+Upon success, the memory referenced by
+.Fa ptr
+is freed and a pointer to the newly allocated memory is returned.
+Note that
+.Fn reallocf
+may move the memory allocation, resulting in a different return value than
+.Fa ptr .
+If
+.Fa ptr
+is
+.Dv NULL ,
+the
+.Fn reallocf
+function behaves identically to
+.Fn malloc
+for the specified size.
+Upon failure, when the requested memory cannot be allocated, the passed pointer
+is freed to ease the problems with traditional coding styles for
+.Fn reallocf
+causing memory leaks in libraries.
+.Sh RETURN VALUES
+The
+.Fn reallocf
+function returns a pointer, possibly identical to
+.Fa ptr ,
+to the allocated memory
+if successful; otherwise a
+.Dv NULL
+pointer is returned, and
+.Va errno
+is set to
+.Er ENOMEM
+if the error was the result of an allocation failure.
+The buffer is deallocated in this case.
+.Sh SEE ALSO
+.Xr brk 2 ,
+.Xr mmap 2 ,
+.Xr alloca 3 ,
+.Xr calloc 3 ,
+.Xr free 3 ,
+.Xr malloc 3 ,
+.Xr posix_memalign 3 ,
+.Xr realloc 3 ,
+.Sh HISTORY
+The
+.Fn reallocf
+function first appeared in
+.Fx 3.0 .

src/reallocf.c

@@ -0,0 +1,48 @@
+/*-
+ * Copyright (c) 1998, M. Warner Losh <imp@freebsd.org>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdlib.h>
+
+void *
+reallocf(void *ptr, size_t size)
+{
+	void *nptr;
+
+	nptr = realloc(ptr, size);
+
+	/*
+	 * When the System V compatibility option (malloc "V" flag) is
+	 * in effect, realloc(ptr, 0) frees the memory and returns NULL.
+	 * So, to avoid double free, call free() only when size != 0.
+	 * realloc(ptr, 0) can't fail when ptr != NULL.
+	 */
+	if (!nptr && ptr && size != 0)
+		free(ptr);
+	return (nptr);
+}