include/ws_diag_control.h

   1 /* ws_diag_control.h
   2  * Turn compiler diagnostic messages on and off.
   3  *
   4  * From FreeRADIUS build.h.
   5  *
   6  * @copyright 2013 The FreeRADIUS server project
   7  *
   8  * That project is covered by the GPLv2, so:
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  */
  12
  13 #ifndef __WS_DIAG_CONTROL_H__
  14 #define __WS_DIAG_CONTROL_H__
  15
  16 #include "ws_compiler_tests.h"
  17
  18 #ifdef __cplusplus
  19 extern "C" {
  20 #endif
  21
  22 #define XSTRINGIFY(x) #x
  23
  24 /*
  25  *      Macros for controlling warnings in various compilers.
  26  */
  27 #define DIAG_JOINSTR(x,y) XSTRINGIFY(x ## y)
  28
  29 /*
  30  * XXX - this is only for GCC or GCC-compatible compilers, and we only use
  31  * it to have a macro that takes a warning as an argument and turns it
  32  * off in the appropriate fashion for Clang and GCC; it should only be
  33  * used internally in this header.
  34  */
  35 #define DIAG_DO_PRAGMA(x) _Pragma (#x)
  36
  37 #if defined(__clang__)
  38   /*
  39    * Clang, so we'd use _Pragma("clang diagnostic XXX"), if it's
  40    * supported.
  41    */
  42   #if WS_IS_AT_LEAST_CLANG_VERSION(2,8)
  43     /*
  44      * This is Clang 2.8 or later: we can use "clang diagnostic ignored -Wxxx"
  45      * and "clang diagnostic push/pop".
  46      */
  47     #define DIAG_PRAGMA(x) DIAG_DO_PRAGMA(clang diagnostic x)
  48     #define DIAG_OFF(x) DIAG_PRAGMA(push) DIAG_PRAGMA(ignored DIAG_JOINSTR(-W,x))
  49     #define DIAG_WARN(x) DIAG_PRAGMA(push) DIAG_PRAGMA(warning DIAG_JOINSTR(-W,x))
  50     #define DIAG_ON(x) DIAG_PRAGMA(pop)
  51   #endif
  52
  53   /*
  54    * Not all versions of Clang understand -Wpedantic.  Clang 4.0 appears
  55    * to be the first version to do so.
  56    */
  57   #if WS_IS_AT_LEAST_CLANG_VERSION(4,0)
  58     #define DIAG_OFF_PEDANTIC DIAG_OFF(pedantic)
  59     #define DIAG_ON_PEDANTIC DIAG_ON(pedantic)
  60   #else
  61     #define DIAG_OFF_PEDANTIC
  62     #define DIAG_ON_PEDANTIC
  63   #endif
  64
  65   /*
  66    * Do any pre-5.0 versions of Clang understand -Winitializer-overrides?
  67    */
  68   #if WS_IS_AT_LEAST_CLANG_VERSION(4,0)
  69     #define DIAG_OFF_INIT_TWICE DIAG_OFF(initializer-overrides)
  70     #define DIAG_ON_INIT_TWICE DIAG_ON(initializer-overrides)
  71   #else
  72     #define DIAG_OFF_INIT_TWICE
  73     #define DIAG_ON_INIT_TWICE
  74   #endif
  75 #elif defined(__GNUC__)
  76   /*
  77    * GCC, or a compiler (other than Clang) that claims to be GCC.
  78    * We assume that the compiler accepts _Pragma("GCC diagnostic xxx")
  79    * even if it's only claiming to be GCC.
  80    */
  81   #if WS_IS_AT_LEAST_GNUC_VERSION(4,8)
  82     /*
  83      * This is GCC 4.8 or later, or a compiler claiming to be that.
  84      * We can use "GCC diagnostic ignored -Wxxx" (introduced in 4.2)
  85      * and "GCC diagnostic push/pop" (introduced in 4.6), *and* gcc
  86      * supports "-Wpedantic" (introduced in 4.8), allowing us to
  87      * turn off pedantic warnings with DIAG_OFF().
  88      */
  89     #define DIAG_PRAGMA(x) DIAG_DO_PRAGMA(GCC diagnostic x)
  90     #define DIAG_OFF(x) DIAG_PRAGMA(push) DIAG_PRAGMA(ignored DIAG_JOINSTR(-W,x))
  91     #define DIAG_WARN(x) DIAG_PRAGMA(push) DIAG_PRAGMA(warning DIAG_JOINSTR(-W,x))
  92     #define DIAG_ON(x) DIAG_PRAGMA(pop)
  93
  94     /*
  95      * We assume GCC 4.8 and later understand -Wpedantic.
  96      */
  97     #define DIAG_OFF_PEDANTIC DIAG_OFF(pedantic)
  98     #define DIAG_ON_PEDANTIC DIAG_ON(pedantic)
  99
 100     /*
 101      * GCC 4.2 and later understand -Woverride-init.
 102      */
 103     #define DIAG_OFF_INIT_TWICE DIAG_OFF(override-init)
 104     #define DIAG_ON_INIT_TWICE DIAG_ON(override-init)
 105   #else
 106     #define DIAG_OFF_PEDANTIC
 107     #define DIAG_ON_PEDANTIC
 108
 109     #define DIAG_OFF_INIT_TWICE
 110     #define DIAG_ON_INIT_TWICE
 111   #endif
 112 #endif
 113
 114 #ifndef DIAG_OFF
 115   /*
 116    * This is none of the above; we don't have any way to turn diagnostics
 117    * on or off.
 118    *
 119    * XXX - you can do that in MSVC, but it's done differently; we'd
 120    * have to have macros for *particular* diagnostics, using the
 121    * warning flag for GCC and Clang and the error number for MSVC.
 122    */
 123   #define DIAG_OFF(x)
 124   #define DIAG_WARN(x)
 125   #define DIAG_ON(x)
 126   #define DIAG_OFF_PEDANTIC
 127   #define DIAG_ON_PEDANTIC
 128   #define DIAG_OFF_INIT_TWICE
 129   #define DIAG_ON_INIT_TWICE
 130 #endif
 131
 132 /* Use for clang specific pragmas, so we can keep -Wpragmas enabled */
 133 #ifdef __clang__
 134 #  define DIAG_OFF_CLANG(x) DIAG_OFF(x)
 135 #  define DIAG_WARN_CLANG(x) DIAG_WARN(x)
 136 #  define DIAG_ON_CLANG(x)  DIAG_ON(x)
 137 #else
 138 #  define DIAG_OFF_CLANG(x)
 139 #  define DIAG_ON_CLANG(x)
 140 #endif
 141
 142 /*
 143  * Suppress complaints about narrowing conversations and about signed vs.
 144  * unsigned comparison.
 145  *
 146  * XXX - this is done solely to squelch complaints from code generated
 147  * by Flex, but newer versions of Flex might fix the code; can we
 148  * check the version of Flex and suppress only the checks that code
 149  * generated by that version of Flex triggers?
 150  */
 151 #if defined(_MSC_VER)
 152   /*
 153    * Suppress:
 154    *
 155    *   warning C4018: signed/unsigned mismatch
 156    *   warning C4244: 'initializing' : conversion from '__int64' to 'int', possible loss of data
 157    *   warning C4267: 'argument' : conversion from 'size_t' to 'int', possible loss of data
 158    *
 159    * as well as Visual Studio Code Analyzer warnings:
 160    *
 161    *   warning C6011: Dereferencing NULL pointer
 162    *   warning C6308: 'realloc' might return null pointer
 163    *   warning C6386: Buffer overrun
 164    *   warning C6387: 'XXX' could be '0'
 165    *   warning C28182: Dereferencing NULL pointer
 166    */
 167   #define DIAG_OFF_FLEX() \
 168     __pragma(warning(push)) \
 169     __pragma(warning(disable:4018)) \
 170     __pragma(warning(disable:4244)) \
 171     __pragma(warning(disable:4267)) \
 172     __pragma(warning(disable:6011)) \
 173     __pragma(warning(disable:6308)) \
 174     __pragma(warning(disable:6386)) \
 175     __pragma(warning(disable:6387)) \
 176     __pragma(warning(disable:28182))
 177   #define DIAG_ON_FLEX() \
 178     __pragma(warning(pop))
 179 #else
 180   /*
 181    * Suppress:
 182    *
 183    *   -Wsigned-compare warnings
 184    *   -Wshorten-64-to-32 warnings, if the compiler *has* -Wshorten-64-to-32
 185    *   -Wunreachable-code warnings
 186    * The version of Flex in the macOS Intel build bots triggers documentation warnings.
 187    *   -Wdocumentation
 188    *
 189    * We use DIAG_OFF() and DIAG_ON(), so we only use features that the
 190    * compiler supports.
 191    *
 192    * We disable -Wshorten-64-to-32 if we're using Clang, or if __APPLE__
 193    * is defined; that option was originally added to an Apple version of
 194    * GCC, and at least some versions of Clang support it - given that
 195    * the Clang work started at Apple, it may be in all versions of Clang.
 196    *
 197    * (Does no version of GCC or Clang support the same generic "you're
 198    * narrowing a value, and you didn't throw in a cast to assert that
 199    * you know what you're doing" warning that MSVC does?)
 200    */
 201   #if defined(__clang__) || defined(__APPLE__)
 202     #define DIAG_OFF_FLEX() \
 203       DIAG_OFF(sign-compare) \
 204       DIAG_OFF(unused-parameter) \
 205       DIAG_OFF(shorten-64-to-32) \
 206       DIAG_OFF(unreachable-code) \
 207       DIAG_OFF(documentation)
 208     #define DIAG_ON_FLEX() \
 209       DIAG_ON(documentation)    \
 210       DIAG_ON(unreachable-code) \
 211       DIAG_ON(shorten-64-to-32) \
 212       DIAG_ON(unused-parameter) \
 213       DIAG_ON(sign-compare)
 214   #else
 215     #define DIAG_OFF_FLEX() \
 216       DIAG_OFF(sign-compare) \
 217       DIAG_OFF(unused-parameter)
 218     #define DIAG_ON_FLEX() \
 219       DIAG_ON(unused-parameter) \
 220       DIAG_ON(sign-compare)
 221   #endif
 222 #endif
 223
 224 /* Disable Lemon warnings. */
 225 #if defined(_MSC_VER)
 226   #define DIAG_OFF_LEMON()
 227   #define DIAG_ON_LEMON()
 228 #else
 229   #define DIAG_OFF_LEMON() \
 230     DIAG_OFF_CLANG(unreachable-code)
 231   #define DIAG_ON_LEMON() \
 232     DIAG_ON_CLANG(unreachable-code)
 233 #endif
 234
 235 /*
 236  * Suppress warnings about casting away constness.
 237  * Do this only if you know that the pointer is to something that can
 238  * be written and, in this context, should be writable.
 239  */
 240 #if defined(__GNUC__) || defined(__clang__)
 241   /*
 242    * GCC or a compiler that claims to be GCC-compatible.
 243    * We throw in Clang just in case clang-cl doesn't define
 244    * __GNUC__; if it does, __GNUC__ should suffice.
 245    */
 246   #define DIAG_OFF_CAST_AWAY_CONST DIAG_OFF(cast-qual)
 247   #define DIAG_ON_CAST_AWAY_CONST DIAG_OFF(cast-qual)
 248 #elif defined(_MSC_VER)
 249   #define DIAG_OFF_CAST_AWAY_CONST
 250   #define DIAG_ON_CAST_AWAY_CONST
 251 #else
 252   #define DIAG_OFF_CAST_AWAY_CONST
 253   #define DIAG_ON_CAST_AWAY_CONST
 254 #endif
 255
 256 /*
 257  * This warning is only supported by GCC since version 7.1 (and not
 258  * Clang or other compilers that claim GNU C support).
 259  */
 260 #if WS_GCC_VERSION >= 70100
 261   #define DIAG_OFF_STRINGOP_OVERFLOW() DIAG_OFF(stringop-overflow=)
 262   #define DIAG_ON_STRINGOP_OVERFLOW() DIAG_ON(stringop-overflow=)
 263 #else
 264   #define DIAG_OFF_STRINGOP_OVERFLOW()
 265   #define DIAG_ON_STRINGOP_OVERFLOW()
 266 #endif
 267
 268 /*
 269  *      For dealing with APIs which are only deprecated in macOS (like the
 270  *      OpenSSL and MIT/Heimdal Kerberos APIs).
 271  *
 272  *      Dear Apple: this is a cross-platform program, and we're not
 273  *      going to use your Shiny New Frameworks on macOS unless there's
 274  *      a sufficiently clear benefit to make it worth our while to have
 275  *      both macOS and non-macOS versions of the code.
 276  */
 277 #ifdef __APPLE__
 278 #  define USES_APPLE_DEPRECATED_API DIAG_OFF(deprecated-declarations)
 279 #  define USES_APPLE_RST DIAG_ON(deprecated-declarations)
 280 #else
 281 #  define USES_APPLE_DEPRECATED_API
 282 #  define USES_APPLE_RST
 283 #endif
 284
 285 #ifdef __cplusplus
 286 }
 287 #endif
 288 #endif /* __WS_DIAG_CONTROL_H__ */