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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 "pcap/compiler-tests.h"
39 
40 #if PCAP_IS_AT_LEAST_CLANG_VERSION(2,8) || PCAP_IS_AT_LEAST_GNUC_VERSION(4,6)
41   /*
42    * Clang and GCC both support this way of putting pragmas into #defines.
43    * We use it only if we have a compiler that supports it; see below
44    * for the code that uses it and the #defines that control whether
45    * that code is used.
46    */
47   #define PCAP_DO_PRAGMA(x) _Pragma (#x)
48 #endif
49 
50 /*
51  * Suppress "enum value not explicitly handled in switch" warnings.
52  * We may have to build on multiple different Windows SDKs, so we
53  * may not be able to include all enum values in a switch, as they
54  * won't necessarily be defined on all the SDKs, and, unlike
55  * #defines, there's no easy way to test whether a given enum has
56  * a given value.  It *could* be done by the configure script or
57  * CMake tests.
58  */
59 #if defined(_MSC_VER)
60   #define DIAG_OFF_ENUM_SWITCH \
61     __pragma(warning(push)) \
62     __pragma(warning(disable:4061))
63   #define DIAG_ON_ENUM_SWITCH \
64     __pragma(warning(pop))
65 #else
66   #define DIAG_OFF_ENUM_SWITCH
67   #define DIAG_ON_ENUM_SWITCH
68 #endif
69 
70 /*
71  * Suppress "switch statement has only a default case" warnings.
72  * There's a switch in bpf_filter.c that only has additional
73  * cases on Linux.
74  */
75 #if defined(_MSC_VER)
76   #define DIAG_OFF_DEFAULT_ONLY_SWITCH \
77     __pragma(warning(push)) \
78     __pragma(warning(disable:4065))
79   #define DIAG_ON_DEFAULT_ONLY_SWITCH \
80     __pragma(warning(pop))
81 #else
82   #define DIAG_OFF_DEFAULT_ONLY_SWITCH
83   #define DIAG_ON_DEFAULT_ONLY_SWITCH
84 #endif
85 
86 /*
87  * Suppress Flex, narrowing, and deprecation warnings.
88  */
89 #if PCAP_IS_AT_LEAST_CLANG_VERSION(2,8)
90   /*
91    * This is Clang 2.8 or later; we can use "clang diagnostic
92    * ignored -Wxxx" and "clang diagnostic push/pop".
93    *
94    * Suppress -Wdocumentation warnings; GCC doesn't support -Wdocumentation,
95    * at least according to the GCC 7.3 documentation.  Apparently, Flex
96    * generates code that upsets at least some versions of Clang's
97    * -Wdocumentation.
98    *
99    * (This could be clang-cl, which defines _MSC_VER, so test this
100    * before testing _MSC_VER.)
101    */
102   #define DIAG_OFF_FLEX \
103     PCAP_DO_PRAGMA(clang diagnostic push) \
104     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wsign-compare") \
105     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wdocumentation") \
106     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wshorten-64-to-32") \
107     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wmissing-noreturn") \
108     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wunused-parameter") \
109     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wunreachable-code")
110   #define DIAG_ON_FLEX \
111     PCAP_DO_PRAGMA(clang diagnostic pop)
112 
113   /*
114    * Suppress the only narrowing warnings you get from Clang.
115    */
116   #define DIAG_OFF_NARROWING \
117     PCAP_DO_PRAGMA(clang diagnostic push) \
118     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wshorten-64-to-32")
119 
120   #define DIAG_ON_NARROWING \
121     PCAP_DO_PRAGMA(clang diagnostic pop)
122 
123   /*
124    * Suppress deprecation warnings.
125    */
126   #define DIAG_OFF_DEPRECATION \
127     PCAP_DO_PRAGMA(clang diagnostic push) \
128     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wdeprecated-declarations")
129   #define DIAG_ON_DEPRECATION \
130     PCAP_DO_PRAGMA(clang diagnostic pop)
131   #define DIAG_OFF_FORMAT_TRUNCATION
132   #define DIAG_ON_FORMAT_TRUNCATION
133 #elif defined(_MSC_VER)
134   /*
135    * This is Microsoft Visual Studio; we can use __pragma(warning(disable:XXXX))
136    * and __pragma(warning(push/pop)).
137    *
138    * Suppress signed-vs-unsigned comparison, narrowing, and unreachable
139    * code warnings.
140    */
141   #define DIAG_OFF_FLEX \
142     __pragma(warning(push)) \
143     __pragma(warning(disable:4127)) \
144     __pragma(warning(disable:4242)) \
145     __pragma(warning(disable:4244)) \
146     __pragma(warning(disable:4702))
147   #define DIAG_ON_FLEX \
148     __pragma(warning(pop))
149 
150   /*
151    * Suppress narrowing warnings.
152    */
153   #define DIAG_OFF_NARROWING \
154     __pragma(warning(push)) \
155     __pragma(warning(disable:4242)) \
156     __pragma(warning(disable:4311))
157   #define DIAG_ON_NARROWING \
158     __pragma(warning(pop))
159 
160   /*
161    * Suppress deprecation warnings.
162    */
163   #define DIAG_OFF_DEPRECATION \
164     __pragma(warning(push)) \
165     __pragma(warning(disable:4996))
166   #define DIAG_ON_DEPRECATION \
167     __pragma(warning(pop))
168   #define DIAG_OFF_FORMAT_TRUNCATION
169   #define DIAG_ON_FORMAT_TRUNCATION
170 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(4,6)
171   /*
172    * This is GCC 4.6 or later, or a compiler claiming to be that.
173    * We can use "GCC diagnostic ignored -Wxxx" (introduced in 4.2)
174    * and "GCC diagnostic push/pop" (introduced in 4.6).
175    */
176   #define DIAG_OFF_FLEX \
177     PCAP_DO_PRAGMA(GCC diagnostic push) \
178     PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wsign-compare") \
179     PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wunused-parameter") \
180     PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wunreachable-code")
181   #define DIAG_ON_FLEX \
182     PCAP_DO_PRAGMA(GCC diagnostic pop)
183 
184   /*
185    * GCC currently doesn't issue any narrowing warnings.
186    */
187   #define DIAG_OFF_NARROWING
188   #define DIAG_ON_NARROWING
189 
190   /*
191    * Suppress deprecation warnings.
192    */
193   #define DIAG_OFF_DEPRECATION \
194     PCAP_DO_PRAGMA(GCC diagnostic push) \
195     PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wdeprecated-declarations")
196   #define DIAG_ON_DEPRECATION \
197     PCAP_DO_PRAGMA(GCC diagnostic pop)
198 
199   /*
200    * Suppress format-truncation= warnings.
201    * GCC 7.1 had introduced this warning option. Earlier versions (at least
202    * one particular copy of GCC 4.6.4) treat the request as a warning.
203    */
204   #if PCAP_IS_AT_LEAST_GNUC_VERSION(7,1)
205     #define DIAG_OFF_FORMAT_TRUNCATION \
206       PCAP_DO_PRAGMA(GCC diagnostic push) \
207       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wformat-truncation=")
208     #define DIAG_ON_FORMAT_TRUNCATION \
209       PCAP_DO_PRAGMA(GCC diagnostic pop)
210   #else
211    #define DIAG_OFF_FORMAT_TRUNCATION
212    #define DIAG_ON_FORMAT_TRUNCATION
213   #endif
214 #else
215   /*
216    * Neither Visual Studio, nor Clang 2.8 or later, nor GCC 4.6 or later
217    * or a compiler claiming to be that; there's nothing we know of that
218    * we can do.
219    */
220   #define DIAG_OFF_FLEX
221   #define DIAG_ON_FLEX
222   #define DIAG_OFF_NARROWING
223   #define DIAG_ON_NARROWING
224   #define DIAG_OFF_DEPRECATION
225   #define DIAG_ON_DEPRECATION
226   #define DIAG_OFF_FORMAT_TRUNCATION
227   #define DIAG_ON_FORMAT_TRUNCATION
228 #endif
229 
230 #ifdef YYBYACC
231   /*
232    * Berkeley YACC.
233    *
234    * It generates a global declaration of yylval, or the appropriately
235    * prefixed version of yylval, in grammar.h, *even though it's been
236    * told to generate a pure parser, meaning it doesn't have any global
237    * variables*.  Bison doesn't do this.
238    *
239    * That causes a warning due to the local declaration in the parser
240    * shadowing the global declaration.
241    *
242    * So, if the compiler warns about that, we turn off -Wshadow warnings.
243    *
244    * In addition, the generated code may have functions with unreachable
245    * code, so suppress warnings about those.
246    */
247   #if PCAP_IS_AT_LEAST_CLANG_VERSION(2,8)
248     /*
249      * This is Clang 2.8 or later (including clang-cl, so test this
250      * before _MSC_VER); we can use "clang diagnostic ignored -Wxxx".
251      */
252     #define DIAG_OFF_BISON_BYACC \
253       PCAP_DO_PRAGMA(clang diagnostic ignored "-Wshadow") \
254       PCAP_DO_PRAGMA(clang diagnostic ignored "-Wunreachable-code")
255   #elif defined(_MSC_VER)
256     /*
257      * This is Microsoft Visual Studio; we can use
258      * __pragma(warning(disable:XXXX)).
259      */
260     #define DIAG_OFF_BISON_BYACC \
261       __pragma(warning(disable:4702))
262   #elif PCAP_IS_AT_LEAST_GNUC_VERSION(4,6)
263     /*
264      * This is GCC 4.6 or later, or a compiler claiming to be that.
265      * We can use "GCC diagnostic ignored -Wxxx" (introduced in 4.2,
266      * but it may not actually work very well prior to 4.6).
267      */
268     #define DIAG_OFF_BISON_BYACC \
269       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wshadow") \
270       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wunreachable-code")
271   #else
272     /*
273      * Neither Clang 2.8 or later nor GCC 4.6 or later or a compiler
274      * claiming to be that; there's nothing we know of that we can do.
275      */
276     #define DIAG_OFF_BISON_BYACC
277   #endif
278 #else
279   /*
280    * Bison.
281    *
282    * The generated code may have functions with unreachable code and
283    * switches with only a default case, so suppress warnings about those.
284    */
285   #if PCAP_IS_AT_LEAST_CLANG_VERSION(2,8)
286     /*
287      * This is Clang 2.8 or later (including clang-cl, so test this
288      * before _MSC_VER); we can use "clang diagnostic ignored -Wxxx".
289      */
290     #define DIAG_OFF_BISON_BYACC \
291       PCAP_DO_PRAGMA(clang diagnostic ignored "-Wunreachable-code")
292   #elif defined(_MSC_VER)
293     /*
294      * This is Microsoft Visual Studio; we can use
295      * __pragma(warning(disable:XXXX)).
296      *
297      * Suppress some /Wall warnings.
298      */
299     #define DIAG_OFF_BISON_BYACC \
300       __pragma(warning(disable:4065)) \
301       __pragma(warning(disable:4127)) \
302       __pragma(warning(disable:4242)) \
303       __pragma(warning(disable:4244)) \
304       __pragma(warning(disable:4702))
305   #elif PCAP_IS_AT_LEAST_GNUC_VERSION(4,6)
306     /*
307      * This is GCC 4.6 or later, or a compiler claiming to be that.
308      * We can use "GCC diagnostic ignored -Wxxx" (introduced in 4.2,
309      * but it may not actually work very well prior to 4.6).
310      */
311     #define DIAG_OFF_BISON_BYACC \
312       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wunreachable-code")
313   #else
314     /*
315      * Neither Clang 2.8 or later nor GCC 4.6 or later or a compiler
316      * claiming to be that; there's nothing we know of that we can do.
317      */
318     #define DIAG_OFF_BISON_BYACC
319   #endif
320 #endif
321 
322 /*
323  * GCC needs this on AIX for longjmp().
324  */
325 #if PCAP_IS_AT_LEAST_GNUC_VERSION(5,1)
326   /*
327    * Beware that the effect of this builtin is more than just squelching the
328    * warning! GCC trusts it enough for the process to segfault if the control
329    * flow reaches the builtin (an infinite empty loop in the same context would
330    * squelch the warning and ruin the process too, albeit in a different way).
331    * So please remember to use this very carefully.
332    */
333   #define PCAP_UNREACHABLE __builtin_unreachable();
334 #else
335   #define PCAP_UNREACHABLE
336 #endif
337 
338 #endif /* _diag_control_h */
339