xref: /freebsd/contrib/tcpdump/diag-control.h (revision 87b759f0fa1f7554d50ce640c40138512bbded44)
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 _diag_control_h
36 #define _diag_control_h
37 
38 #include "compiler-tests.h"
39 
40 #ifndef _MSC_VER
41   /*
42    * Clang and GCC both support this way of putting pragmas into #defines.
43    * We don't use it unless we have a compiler that supports it; the
44    * warning-suppressing pragmas differ between Clang and GCC, so we test
45    * for both of those separately.
46    */
47   #define DIAG_DO_PRAGMA(x) _Pragma (#x)
48 #endif
49 
50 /*
51  * XL C 12.1 and 13.1 for AIX require no attention in this department.
52  * XL C 16.1 defines both __GNUC__ and __clang__, so has to be tested first.
53  */
54 #if ND_IS_AT_LEAST_XL_C_VERSION(16,1)
55   /*
56    * See respective Clang note below.
57    */
58   #define DIAG_OFF_ASSIGN_ENUM \
59     DIAG_DO_PRAGMA(clang diagnostic push) \
60     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wassign-enum")
61   #define DIAG_ON_ASSIGN_ENUM \
62     DIAG_DO_PRAGMA(clang diagnostic pop)
63 /*
64  * The current clang compilers also define __GNUC__ and __GNUC_MINOR__
65  * thus we need to test the clang case before the GCC one
66  */
67 #elif ND_IS_AT_LEAST_CLANG_VERSION(2,8)
68   /*
69    * Clang complains if you OR together multiple enum values of a
70    * given enum type and them pass it as an argument of that enum
71    * type.  Some libcap-ng routines use enums to define bit flags;
72    * we want to squelch the warnings that produces.
73    */
74   #define DIAG_OFF_ASSIGN_ENUM \
75     DIAG_DO_PRAGMA(clang diagnostic push) \
76     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wassign-enum")
77   #define DIAG_ON_ASSIGN_ENUM \
78     DIAG_DO_PRAGMA(clang diagnostic pop)
79 
80   /*
81    * It also legitimately complains about some code in the BSD
82    * getopt_long() - that code explicitly and deliberately
83    * violates the contract by permuting the argument vector
84    * (declared as char const *argv[], meaning "I won't change
85    * the vector by changing any of its elements), as do the
86    * GNU and Solaris getopt_long().  This is documented in the
87    * man pages for all versions; it can be suppressed by setting
88    * the environment variable POSIXLY_CORRECT or by putting a "+"
89    * at the beginning of the option string.
90    *
91    * We suppress the warning.
92    */
93   #define DIAG_OFF_CAST_QUAL \
94     DIAG_DO_PRAGMA(clang diagnostic push) \
95     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wcast-qual")
96   #define DIAG_ON_CAST_QUAL \
97     DIAG_DO_PRAGMA(clang diagnostic pop)
98 
99   /*
100    * Suppress deprecation warnings.
101    */
102   #define DIAG_OFF_DEPRECATION \
103     DIAG_DO_PRAGMA(clang diagnostic push) \
104     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wdeprecated-declarations")
105   #define DIAG_ON_DEPRECATION \
106     DIAG_DO_PRAGMA(clang diagnostic pop)
107 
108   /*
109    * Clang supports the generic C11 extension even if run with the -std=gnu99
110    * flag, which leads FreeBSD <sys/cdefs.h> to use the extension, which
111    * results in Clang emitting a -Wc11-extensions warning. The warning is not
112    * documented in the user manual, but it happens with Clang 10.0.1 on
113    * FreeBSD 12.2, so let's use that as a reference.
114    */
115   #if ND_IS_AT_LEAST_CLANG_VERSION(10,0)
116     #define DIAG_OFF_C11_EXTENSIONS \
117       DIAG_DO_PRAGMA(clang diagnostic push) \
118       DIAG_DO_PRAGMA(clang diagnostic ignored "-Wc11-extensions")
119     #define DIAG_ON_C11_EXTENSIONS \
120       DIAG_DO_PRAGMA(clang diagnostic pop)
121   #endif
122 
123   /*
124    * When Clang correctly detects an old-style function prototype after
125    * preprocessing, the warning can be irrelevant to this source tree because
126    * the prototype comes from a system header macro.
127    */
128   #if ND_IS_AT_LEAST_CLANG_VERSION(5,0)
129     #define DIAG_OFF_STRICT_PROTOTYPES \
130       DIAG_DO_PRAGMA(clang diagnostic push) \
131       DIAG_DO_PRAGMA(clang diagnostic ignored "-Wstrict-prototypes")
132     #define DIAG_ON_STRICT_PROTOTYPES \
133       DIAG_DO_PRAGMA(clang diagnostic pop)
134   #endif
135 #elif ND_IS_AT_LEAST_GNUC_VERSION(4,2)
136   /* GCC apparently doesn't complain about ORing enums together. */
137 
138   /*
139    * It does, however, complain about casting away constness in
140    * missing/getopt_long.c.
141    */
142   #define DIAG_OFF_CAST_QUAL \
143     DIAG_DO_PRAGMA(GCC diagnostic push) \
144     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wcast-qual")
145   #define DIAG_ON_CAST_QUAL \
146     DIAG_DO_PRAGMA(GCC diagnostic pop)
147 
148   #if ND_IS_AT_LEAST_GNUC_VERSION(4,5)
149     /*
150      * GCC warns about unused return values if a function is marked as
151      * "warn about ignoring this function's return value".
152      *
153      * Clang appears to let you ignore a result without a warning by
154      * casting the function result to void, so we don't appear to
155      * need this for Clang.
156      */
157     #define DIAG_OFF_WARN_UNUSED_RESULT \
158       DIAG_DO_PRAGMA(GCC diagnostic push) \
159       DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wunused-result")
160     #define DIAG_ON_WARN_UNUSED_RESULT \
161       DIAG_DO_PRAGMA(GCC diagnostic pop)
162   #endif
163 
164   /*
165    * Suppress deprecation warnings.
166    */
167   #define DIAG_OFF_DEPRECATION \
168     DIAG_DO_PRAGMA(GCC diagnostic push) \
169     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wdeprecated-declarations")
170   #define DIAG_ON_DEPRECATION \
171     DIAG_DO_PRAGMA(GCC diagnostic pop)
172   /*
173    * GCC supports -Wc99-c11-compat since version 5.1.0, but the warning does
174    * not trigger for now, so let's just leave it be.
175    *
176    * GCC does not currently generate any -Wstrict-prototypes warnings that
177    * would need silencing as is done for Clang above.
178    */
179 #endif
180 
181 /*
182  * GCC needs this on AIX for longjmp().
183  */
184 #if ND_IS_AT_LEAST_GNUC_VERSION(5,1)
185   /*
186    * Beware that the effect of this builtin is more than just squelching the
187    * warning! GCC trusts it enough for the process to segfault if the control
188    * flow reaches the builtin (an infinite empty loop in the same context would
189    * squelch the warning and ruin the process too, albeit in a different way).
190    * So please remember to use this very carefully.
191    */
192   #define ND_UNREACHABLE __builtin_unreachable();
193 #endif
194 
195 #ifndef DIAG_OFF_ASSIGN_ENUM
196 #define DIAG_OFF_ASSIGN_ENUM
197 #endif
198 #ifndef DIAG_ON_ASSIGN_ENUM
199 #define DIAG_ON_ASSIGN_ENUM
200 #endif
201 #ifndef DIAG_OFF_CAST_QUAL
202 #define DIAG_OFF_CAST_QUAL
203 #endif
204 #ifndef DIAG_ON_CAST_QUAL
205 #define DIAG_ON_CAST_QUAL
206 #endif
207 #ifndef DIAG_OFF_WARN_UNUSED_RESULT
208 #define DIAG_OFF_WARN_UNUSED_RESULT
209 #endif
210 #ifndef DIAG_ON_WARN_UNUSED_RESULT
211 #define DIAG_ON_WARN_UNUSED_RESULT
212 #endif
213 #ifndef DIAG_OFF_DEPRECATION
214 #define DIAG_OFF_DEPRECATION
215 #endif
216 #ifndef DIAG_ON_DEPRECATION
217 #define DIAG_ON_DEPRECATION
218 #endif
219 #ifndef DIAG_OFF_C11_EXTENSIONS
220 #define DIAG_OFF_C11_EXTENSIONS
221 #endif
222 #ifndef DIAG_ON_C11_EXTENSIONS
223 #define DIAG_ON_C11_EXTENSIONS
224 #endif
225 #ifndef DIAG_OFF_STRICT_PROTOTYPES
226 #define DIAG_OFF_STRICT_PROTOTYPES
227 #endif
228 #ifndef DIAG_ON_STRICT_PROTOTYPES
229 #define DIAG_ON_STRICT_PROTOTYPES
230 #endif
231 #ifndef ND_UNREACHABLE
232 #define ND_UNREACHABLE
233 #endif
234 
235 #endif /* _diag_control_h */
236