The Tcpdump Group git mirrors - tcpdump/blob - diag-control.h

   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 #elif ND_IS_AT_LEAST_SUNC_VERSION(5,5)
 180   /*
 181    * error_messages() is a valid pragma.
 182    */
 183   #if ND_IS_AT_LEAST_SUNC_VERSION(5,13)
 184     /*
 185      * E_DEPRECATED_ATT is a valid warning tag.
 186      */
 187     #define DIAG_OFF_DEPRECATION \
 188       DIAG_DO_PRAGMA(error_messages(off,E_DEPRECATED_ATT))
 189     #define DIAG_ON_DEPRECATION \
 190       DIAG_DO_PRAGMA(error_messages(default,E_DEPRECATED_ATT))
 191   #endif
 192 #endif
 193
 194 /*
 195  * GCC needs this on AIX for longjmp().
 196  *
 197  * We call it ND_NOT_REACHABLE rather than ND_UNREACHABLE, as, at
 198  * least on some versions of Illumos (and Solaris?), ND_UNREACHABLE
 199  * is defined differently by <net/if.h>.
 200  */
 201 #if ND_IS_AT_LEAST_GNUC_VERSION(5,1)
 202   /*
 203    * Beware that the effect of this builtin is more than just squelching the
 204    * warning! GCC trusts it enough for the process to segfault if the control
 205    * flow reaches the builtin (an infinite empty loop in the same context would
 206    * squelch the warning and ruin the process too, albeit in a different way).
 207    * So please remember to use this very carefully.
 208    */
 209   #define ND_NOT_REACHABLE __builtin_unreachable();
 210 #endif
 211
 212 #ifndef DIAG_OFF_ASSIGN_ENUM
 213 #define DIAG_OFF_ASSIGN_ENUM
 214 #endif
 215 #ifndef DIAG_ON_ASSIGN_ENUM
 216 #define DIAG_ON_ASSIGN_ENUM
 217 #endif
 218 #ifndef DIAG_OFF_CAST_QUAL
 219 #define DIAG_OFF_CAST_QUAL
 220 #endif
 221 #ifndef DIAG_ON_CAST_QUAL
 222 #define DIAG_ON_CAST_QUAL
 223 #endif
 224 #ifndef DIAG_OFF_WARN_UNUSED_RESULT
 225 #define DIAG_OFF_WARN_UNUSED_RESULT
 226 #endif
 227 #ifndef DIAG_ON_WARN_UNUSED_RESULT
 228 #define DIAG_ON_WARN_UNUSED_RESULT
 229 #endif
 230 #ifndef DIAG_OFF_DEPRECATION
 231 #define DIAG_OFF_DEPRECATION
 232 #endif
 233 #ifndef DIAG_ON_DEPRECATION
 234 #define DIAG_ON_DEPRECATION
 235 #endif
 236 #ifndef DIAG_OFF_C11_EXTENSIONS
 237 #define DIAG_OFF_C11_EXTENSIONS
 238 #endif
 239 #ifndef DIAG_ON_C11_EXTENSIONS
 240 #define DIAG_ON_C11_EXTENSIONS
 241 #endif
 242 #ifndef DIAG_OFF_STRICT_PROTOTYPES
 243 #define DIAG_OFF_STRICT_PROTOTYPES
 244 #endif
 245 #ifndef DIAG_ON_STRICT_PROTOTYPES
 246 #define DIAG_ON_STRICT_PROTOTYPES
 247 #endif
 248 #ifndef ND_NOT_REACHABLE
 249 #define ND_NOT_REACHABLE
 250 #endif
 251
 252 #endif /* _diag_control_h */