confstr.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 4. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if defined(LIBC_SCCS) && !defined(lint)
33static char sccsid[] = "@(#)confstr.c	8.1 (Berkeley) 6/4/93";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/11/lib/libc/gen/confstr.c 330897 2018-03-14 03:19:51Z eadler $");
37
38#include <sys/param.h>
39
40#include <errno.h>
41#include <limits.h>
42#include <paths.h>
43#include <string.h>
44#include <unistd.h>
45
46
47size_t
48confstr(int name, char *buf, size_t len)
49{
50	const char *p;
51	const char UPE[] = "unsupported programming environment";
52
53	switch (name) {
54	case _CS_PATH:
55		p = _PATH_STDPATH;
56		goto docopy;
57
58		/*
59		 * POSIX/SUS ``Programming Environments'' stuff
60		 *
61		 * We don't support more than one programming environment
62		 * on any platform (yet), so we just return the empty
63		 * string for the environment we are compiled for,
64		 * and the string "unsupported programming environment"
65		 * for anything else.  (The Standard says that if these
66		 * values are used on a system which does not support
67		 * this environment -- determined via sysconf() -- then
68		 * the value we return is unspecified.  So, we return
69		 * something which will cause obvious breakage.)
70		 */
71	case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
72	case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
73	case _CS_POSIX_V6_ILP32_OFF32_LIBS:
74	case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
75	case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
76	case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
77		/*
78		 * These two environments are never supported.
79		 */
80		p = UPE;
81		goto docopy;
82
83	case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
84	case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
85	case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
86		if (sizeof(long) * CHAR_BIT == 32 &&
87		    sizeof(off_t) > sizeof(long))
88			p = "";
89		else
90			p = UPE;
91		goto docopy;
92
93	case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
94	case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
95	case _CS_POSIX_V6_LP64_OFF64_LIBS:
96		if (sizeof(long) * CHAR_BIT >= 64 &&
97		    sizeof(void *) * CHAR_BIT >= 64 &&
98		    sizeof(int) * CHAR_BIT >= 32 &&
99		    sizeof(off_t) >= sizeof(long))
100			p = "";
101		else
102			p = UPE;
103		goto docopy;
104
105	case _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS:
106		/* XXX - should have more complete coverage */
107		if (sizeof(long) * CHAR_BIT >= 64)
108			p = "_POSIX_V6_LP64_OFF64";
109		else
110			p = "_POSIX_V6_ILP32_OFFBIG";
111		goto docopy;
112
113docopy:
114		if (len != 0 && buf != NULL)
115			strlcpy(buf, p, len);
116		return (strlen(p) + 1);
117
118	default:
119		errno = EINVAL;
120		return (0);
121	}
122	/* NOTREACHED */
123}
124