xref: /freebsd/contrib/libpcap/pcap/compiler-tests.h (revision 6ef644f5889afbd0f681b08ed1a2f369524af83e)
1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
2 /*
3  * Copyright (c) 1993, 1994, 1995, 1996, 1997
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the Computer Systems
17  *	Engineering Group at Lawrence Berkeley Laboratory.
18  * 4. Neither the name of the University nor of the Laboratory may be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #ifndef lib_pcap_compiler_tests_h
36 #define lib_pcap_compiler_tests_h
37 
38 /*
39  * This was introduced by Clang:
40  *
41  *     https://clang.llvm.org/docs/LanguageExtensions.html#has-attribute
42  *
43  * in some version (which version?); it has been picked up by GCC 5.0.
44  */
45 #ifndef __has_attribute
46   /*
47    * It's a macro, so you can check whether it's defined to check
48    * whether it's supported.
49    *
50    * If it's not, define it to always return 0, so that we move on to
51    * the fallback checks.
52    */
53   #define __has_attribute(x) 0
54 #endif
55 
56 /*
57  * Note that the C90 spec's "6.8.1 Conditional inclusion" and the
58  * C99 spec's and C11 spec's "6.10.1 Conditional inclusion" say:
59  *
60  *    Prior to evaluation, macro invocations in the list of preprocessing
61  *    tokens that will become the controlling constant expression are
62  *    replaced (except for those macro names modified by the defined unary
63  *    operator), just as in normal text.  If the token "defined" is
64  *    generated as a result of this replacement process or use of the
65  *    "defined" unary operator does not match one of the two specified
66  *    forms prior to macro replacement, the behavior is undefined.
67  *
68  * so you shouldn't use defined() in a #define that's used in #if or
69  * #elif.  Some versions of Clang, for example, will warn about this.
70  *
71  * Instead, we check whether the pre-defined macros for particular
72  * compilers are defined and, if not, define the "is this version XXX
73  * or a later version of this compiler" macros as 0.
74  */
75 
76 /*
77  * Check whether this is GCC major.minor or a later release, or some
78  * compiler that claims to be "just like GCC" of that version or a
79  * later release.
80  */
81 
82 #if ! defined(__GNUC__)
83   /* Not GCC and not "just like GCC" */
84   #define PCAP_IS_AT_LEAST_GNUC_VERSION(major, minor) 0
85 #else
86   /* GCC or "just like GCC" */
87   #define PCAP_IS_AT_LEAST_GNUC_VERSION(major, minor) \
88 	(__GNUC__ > (major) || \
89 	 (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
90 #endif
91 
92 /*
93  * Check whether this is Clang major.minor or a later release.
94  */
95 
96 #if !defined(__clang__)
97   /* Not Clang */
98   #define PCAP_IS_AT_LEAST_CLANG_VERSION(major, minor) 0
99 #else
100   /* Clang */
101   #define PCAP_IS_AT_LEAST_CLANG_VERSION(major, minor) \
102 	(__clang_major__ > (major) || \
103 	 (__clang_major__ == (major) && __clang_minor__ >= (minor)))
104 #endif
105 
106 /*
107  * Check whether this is Sun C/SunPro C/Oracle Studio major.minor
108  * or a later release.
109  *
110  * The version number in __SUNPRO_C is encoded in hex BCD, with the
111  * uppermost hex digit being the major version number, the next
112  * one or two hex digits being the minor version number, and
113  * the last digit being the patch version.
114  *
115  * It represents the *compiler* version, not the product version;
116  * see
117  *
118  *    https://sourceforge.net/p/predef/wiki/Compilers/
119  *
120  * for a partial mapping, which we assume continues for later
121  * 12.x product releases.
122  */
123 
124 #if ! defined(__SUNPRO_C)
125   /* Not Sun/Oracle C */
126   #define PCAP_IS_AT_LEAST_SUNC_VERSION(major,minor) 0
127 #else
128   /* Sun/Oracle C */
129   #define PCAP_SUNPRO_VERSION_TO_BCD(major, minor) \
130 	(((minor) >= 10) ? \
131 	    (((major) << 12) | (((minor)/10) << 8) | (((minor)%10) << 4)) : \
132 	    (((major) << 8) | ((minor) << 4)))
133   #define PCAP_IS_AT_LEAST_SUNC_VERSION(major,minor) \
134 	(__SUNPRO_C >= PCAP_SUNPRO_VERSION_TO_BCD((major), (minor)))
135 #endif
136 
137 /*
138  * Check whether this is IBM XL C major.minor or a later release.
139  *
140  * The version number in __xlC__ has the major version in the
141  * upper 8 bits and the minor version in the lower 8 bits.
142  * On AIX __xlC__ is always defined, __ibmxl__ becomes defined in XL C 16.1.
143  * On Linux since XL C 13.1.6 __xlC__ is not defined by default anymore, but
144  * __ibmxl__ is defined since at least XL C 13.1.1.
145  */
146 
147 #if ! defined(__xlC__) && ! defined(__ibmxl__)
148   /* Not XL C */
149   #define PCAP_IS_AT_LEAST_XL_C_VERSION(major,minor) 0
150 #else
151   /* XL C */
152   #if defined(__ibmxl__)
153     /*
154      * Later Linux version of XL C; use __ibmxl_version__ to test
155      * the version.
156      */
157     #define PCAP_IS_AT_LEAST_XL_C_VERSION(major, minor) \
158 	(__ibmxl_version__ > (major) || \
159 	 (__ibmxl_version__ == (major) && __ibmxl_release__ >= (minor)))
160   #else /* __ibmxl__ */
161     /*
162      * __ibmxl__ not defined; use __xlC__ to test the version.
163      */
164     #define PCAP_IS_AT_LEAST_XL_C_VERSION(major, minor) \
165 	(__xlC__ >= (((major) << 8) | (minor)))
166   #endif /* __ibmxl__ */
167 #endif
168 
169 /*
170  * Check whether this is HP aC++/HP C major.minor or a later release.
171  *
172  * The version number in __HP_aCC is encoded in zero-padded decimal BCD,
173  * with the "A." stripped off, the uppermost two decimal digits being
174  * the major version number, the next two decimal digits being the minor
175  * version number, and the last two decimal digits being the patch version.
176  * (Strip off the A., remove the . between the major and minor version
177  * number, and add two digits of patch.)
178  */
179 
180 #if ! defined(__HP_aCC)
181   /* Not HP C */
182   #define PCAP_IS_AT_LEAST_HP_C_VERSION(major,minor) 0
183 #else
184   /* HP C */
185   #define PCAP_IS_AT_LEAST_HP_C_VERSION(major,minor) \
186 	(__HP_aCC >= ((major)*10000 + (minor)*100))
187 #endif
188 
189 #endif /* lib_pcap_compiler_tests_h */
190