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   #define DIAG_OFF_CAST_QUAL
  65   #define DIAG_ON_CAST_QUAL
  66   #define DIAG_OFF_DEPRECATION
  67   #define DIAG_ON_DEPRECATION
  68 /*
  69  * The current clang compilers also define __GNUC__ and __GNUC_MINOR__
  70  * thus we need to test the clang case before the GCC one
  71  */
  72 #elif ND_IS_AT_LEAST_CLANG_VERSION(2,8)
  73   /*
  74    * Clang complains if you OR together multiple enum values of a
  75    * given enum type and them pass it as an argument of that enum
  76    * type.  Some libcap-ng routines use enums to define bit flags;
  77    * we want to squelch the warnings that produces.
  78    */
  79   #define DIAG_OFF_ASSIGN_ENUM \
  80     DIAG_DO_PRAGMA(clang diagnostic push) \
  81     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wassign-enum")
  82   #define DIAG_ON_ASSIGN_ENUM \
  83     DIAG_DO_PRAGMA(clang diagnostic pop)
  84
  85   /*
  86    * It also legitimately complains about some code in the BSD
  87    * getopt_long() - that code explicitly and deliberately
  88    * violates the contract by permuting the argument vector
  89    * (declared as char const *argv[], meaning "I won't change
  90    * the vector by changing any of its elements), as do the
  91    * GNU and Solaris getopt_long().  This is documented in the
  92    * man pages for all versions; it can be suppressed by setting
  93    * the environment variable POSIXLY_CORRECT or by putting a "+"
  94    * at the beginning of the option string.
  95    *
  96    * We suppress the warning.
  97    */
  98   #define DIAG_OFF_CAST_QUAL \
  99     DIAG_DO_PRAGMA(clang diagnostic push) \
 100     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wcast-qual")
 101   #define DIAG_ON_CAST_QUAL \
 102     DIAG_DO_PRAGMA(clang diagnostic pop)
 103
 104   /*
 105    * Suppress deprecation warnings.
 106    */
 107   #define DIAG_OFF_DEPRECATION \
 108     DIAG_DO_PRAGMA(clang diagnostic push) \
 109     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wdeprecated-declarations")
 110   #define DIAG_ON_DEPRECATION \
 111     DIAG_DO_PRAGMA(clang diagnostic pop)
 112
 113   /*
 114    * Clang supports the generic C11 extension even if run with the -std=gnu99
 115    * flag, which leads FreeBSD <sys/cdefs.h> to use the extension, which
 116    * results in Clang emitting a -Wc11-extensions warning. The warning is not
 117    * documented in the user manual, but it happens with Clang 10.0.1 on
 118    * FreeBSD 12.2, so let's use that as a reference.
 119    */
 120   #if ND_IS_AT_LEAST_CLANG_VERSION(10,0)
 121     #define DIAG_OFF_C11_EXTENSIONS \
 122       DIAG_DO_PRAGMA(clang diagnostic push) \
 123       DIAG_DO_PRAGMA(clang diagnostic ignored "-Wc11-extensions")
 124     #define DIAG_ON_C11_EXTENSIONS \
 125       DIAG_DO_PRAGMA(clang diagnostic pop)
 126   #endif
 127 #elif ND_IS_AT_LEAST_GNUC_VERSION(4,2)
 128   /* GCC apparently doesn't complain about ORing enums together. */
 129   #define DIAG_OFF_ASSIGN_ENUM
 130   #define DIAG_ON_ASSIGN_ENUM
 131
 132   /*
 133    * It does, however, complain about casting away constness in
 134    * missing/getopt_long.c.
 135    */
 136   #define DIAG_OFF_CAST_QUAL \
 137     DIAG_DO_PRAGMA(GCC diagnostic push) \
 138     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wcast-qual")
 139   #define DIAG_ON_CAST_QUAL \
 140     DIAG_DO_PRAGMA(GCC diagnostic pop)
 141
 142   /*
 143    * Suppress deprecation warnings.
 144    */
 145   #define DIAG_OFF_DEPRECATION \
 146     DIAG_DO_PRAGMA(GCC diagnostic push) \
 147     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wdeprecated-declarations")
 148   #define DIAG_ON_DEPRECATION \
 149     DIAG_DO_PRAGMA(GCC diagnostic pop)
 150   /*
 151    * GCC supports -Wc99-c11-compat since version 5.1.0, but the warning does
 152    * not trigger for now, so let's just leave it be.
 153    */
 154 #else
 155   #define DIAG_OFF_ASSIGN_ENUM
 156   #define DIAG_ON_ASSIGN_ENUM
 157   #define DIAG_OFF_CAST_QUAL
 158   #define DIAG_ON_CAST_QUAL
 159   #define DIAG_OFF_DEPRECATION
 160   #define DIAG_ON_DEPRECATION
 161 #endif
 162
 163 #ifndef DIAG_OFF_C11_EXTENSIONS
 164 #define DIAG_OFF_C11_EXTENSIONS
 165 #endif
 166 #ifndef DIAG_ON_C11_EXTENSIONS
 167 #define DIAG_ON_C11_EXTENSIONS
 168 #endif
 169
 170 /*
 171  * GCC needs this on AIX for longjmp().
 172  */
 173 #if ND_IS_AT_LEAST_GNUC_VERSION(5,1)
 174   /*
 175    * Beware that the effect of this builtin is more than just squelching the
 176    * warning! GCC trusts it enough for the process to segfault if the control
 177    * flow reaches the builtin (an infinite empty loop in the same context would
 178    * squelch the warning and ruin the process too, albeit in a different way).
 179    * So please remember to use this very carefully.
 180    */
 181   #define ND_UNREACHABLE __builtin_unreachable();
 182 #else
 183   #define ND_UNREACHABLE
 184 #endif
 185
 186 #endif /* _diag_control_h */