The Tcpdump Group git mirrors - libpcap/blob - pcap/funcattrs.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.
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  19  *    to endorse or promote products derived from this software without
  20  *    specific prior written permission.
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  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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  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 lib_pcap_funcattrs_h
  36 #define lib_pcap_funcattrs_h
  37
  38 /*
  39  * Attributes to apply to functions and their arguments, using various
  40  * compiler-specific extensions.
  41  */
  42
  43 /*
  44  * PCAP_API_DEF must be used when defining *data* exported from
  45  * libpcap.  It can be used when defining *functions* exported
  46  * from libpcap, but it doesn't have to be used there.  It
  47  * should not be used in declarations in headers.
  48  *
  49  * PCAP_API must be used when *declaring* data or functions
  50  * exported from libpcap; PCAP_API_DEF won't work on all platforms.
  51  */
  52
  53 /*
  54  * This was introduced by Clang:
  55  *
  56  *     http://clang.llvm.org/docs/LanguageExtensions.html#has-attribute
  57  *
  58  * in some version (which version?); it has been picked up by GCC 5.0.
  59  */
  60 #ifndef __has_attribute
  61   /*
  62    * It's a macro, so you can check whether it's defined to check
  63    * whether it's supported.
  64    *
  65    * If it's not, define it to always return 0, so that we move on to
  66    * the fallback checks.
  67    */
  68   #define __has_attribute(x) 0
  69 #endif
  70
  71 /*
  72  * Check whether this is GCC major.minor or a later release, or some
  73  * compiler that claims to be "just like GCC" of that version or a
  74  * later release.
  75  */
  76 #define PCAP_IS_AT_LEAST_GNUC_VERSION(major, minor) \
  77         (defined(__GNUC__) && \
  78             (__GNUC__ > (major) || \
  79              (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))))
  80
  81 /*
  82  * Check wehether this is Sun C/SunPro C/Oracle Studio major.minor
  83  * or a later release.
  84  *
  85  * The version number in __SUNPRO_C is encoded in hex BCD, with the
  86  * uppermost hex digit being the major version number, the next
  87  * one or two hex digits being the minor version number, and
  88  * the last digit being the patch version.
  89  *
  90  * It represents the *compiler* version, not the product version;
  91  * see
  92  *
  93  *    https://sourceforge.net/p/predef/wiki/Compilers/
  94  *
  95  * for a partial mapping, which we assume continues for later
  96  * 12.x product releases.
  97  */
  98 #define PCAP_SUNPRO_VERSION_TO_BCD(major, minor) \
  99         (((minor) >= 10) ? \
 100             (((major) << 12) | (((minor)/10) << 8) | (((minor)%10) << 4)) : \
 101             (((major) << 8) | ((minor) << 4)))
 102 #define PCAP_IS_AT_LEAST_SUNC_VERSION(major, minor) \
 103         (defined(__SUNPRO_C) && \
 104             (__SUNPRO_C >= PCAP_SUNPRO_VERSION_TO_BCD((major), (minor))))
 105
 106 /*
 107  * Check wehether this is IBM XL C major.minor or a later release.
 108  *
 109  * The version number in __xlC__ has the major version in the
 110  * upper 8 bits and the minor version in the lower 8 bits.
 111  */
 112 #define PCAP_IS_AT_LEAST_XL_C_VERSION(major, minor) \
 113         (defined(__xlC__) && __xlC__ >= (((major) << 8) | (minor)))
 114
 115 /*
 116  * Check wehether this is Sun C/SunPro C/Oracle Studio major.minor
 117  * or a later release.
 118  *
 119  * The version number in __HP_aCC is encoded in zero-padded decimal BCD,
 120  * with the "A." stripped off, the uppermost two decimal digits being
 121  * the major version number, the next two decimal digits being the minor
 122  * version number, and the last two decimal digits being the patch version.
 123  * (Strip off the A., remove the . between the major and minor version
 124  * number, and add two digits of patch.)
 125  */
 126 #define PCAP_IS_AT_LEAST_HP_C_VERSION(major, minor) \
 127         (defined(__HP_aCC) && \
 128             (__HP_aCC >= ((major)*10000 + (minor)*100)))
 129
 130 #if defined(_WIN32)
 131   #ifdef BUILDING_PCAP
 132     /*
 133      * We're compiling libpcap, so we should export functions in our
 134      * API.
 135      */
 136     #define PCAP_API_DEF        __declspec(dllexport)
 137   #else
 138     #define PCAP_API_DEF        __declspec(dllimport)
 139   #endif
 140 #elif defined(MSDOS)
 141   /* XXX - does this need special treatment? */
 142   #define PCAP_API_DEF
 143 #else /* UN*X */
 144   #ifdef BUILDING_PCAP
 145     /*
 146      * We're compiling libpcap, so we should export functions in our API.
 147      * The compiler might be configured not to export functions from a
 148      * shared library by default, so we might have to explicitly mark
 149      * functions as exported.
 150      */
 151     #if PCAP_IS_AT_LEAST_GNUC_VERSION(3, 4) \
 152         || PCAP_IS_AT_LEAST_XL_C_VERSION(12, 0)
 153       /*
 154        * GCC 3.4 or later, or some compiler asserting compatibility with
 155        * GCC 3.4 or later, or XL C 13.0 or later, so we have
 156        * __attribute__((visibility()).
 157        */
 158       #define PCAP_API_DEF      __attribute__((visibility("default")))
 159     #elif PCAP_IS_AT_LEAST_SUNC_VERSION(5, 5)
 160       /*
 161        * Sun C 5.5 or later, so we have __global.
 162        * (Sun C 5.9 and later also have __attribute__((visibility()),
 163        * but there's no reason to prefer it with Sun C.)
 164        */
 165       #define PCAP_API_DEF      __global
 166     #else
 167       /*
 168        * We don't have anything to say.
 169        */
 170       #define PCAP_API_DEF
 171     #endif
 172   #else
 173     /*
 174      * We're not building libpcap.
 175      */
 176     #define PCAP_API_DEF
 177   #endif
 178 #endif /* _WIN32/MSDOS/UN*X */
 179
 180 #define PCAP_API        PCAP_API_DEF extern
 181
 182 /*
 183  * PCAP_NORETURN, before a function declaration, means "this function
 184  * never returns".  (It must go before the function declaration, e.g.
 185  * "extern PCAP_NORETURN func(...)" rather than after the function
 186  * declaration, as the MSVC version has to go before the declaration.)
 187  */
 188 #if __has_attribute(noreturn) \
 189     || PCAP_IS_AT_LEAST_GNUC_VERSION(2, 5) \
 190     || PCAP_IS_AT_LEAST_SUNC_VERSION(5, 9) \
 191     || PCAP_IS_AT_LEAST_XL_C_VERSION(10, 1) \
 192     || PCAP_IS_AT_LEAST_HP_C_VERSION(6, 10)
 193   /*
 194    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
 195    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
 196    * and later (do any earlier versions of XL C support this?), or
 197    * HP aCC A.06.10 and later.
 198    */
 199   #define PCAP_NORETURN __attribute((noreturn))
 200 #elif defined(_MSC_VER)
 201   /*
 202    * MSVC.
 203    */
 204   #define PCAP_NORETURN __declspec(noreturn)
 205 #else
 206   #define PCAP_NORETURN
 207 #endif
 208
 209 /*
 210  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
 211  * does printf-style formatting, with the xth argument being the format
 212  * string and the yth argument being the first argument for the format
 213  * string".
 214  */
 215 #if __has_attribute(__format__) \
 216     || PCAP_IS_AT_LEAST_GNUC_VERSION(2, 3) \
 217     || PCAP_IS_AT_LEAST_XL_C_VERSION(10, 1) \
 218     || PCAP_IS_AT_LEAST_HP_C_VERSION(6, 10)
 219   /*
 220    * Compiler with support for it, or GCC 2.3 and later, or IBM XL C 10.1
 221    * and later (do any earlier versions of XL C support this?),
 222    * or HP aCC A.06.10 and later.
 223    */
 224   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
 225 #else
 226   #define PCAP_PRINTFLIKE(x,y)
 227 #endif
 228
 229 /*
 230  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
 231  * function as deprecated.
 232  *
 233  * The first argument is the name of the function; the second argument is
 234  * a string giving the warning message to use if the compiler supports that.
 235  *
 236  * (Thank you, Microsoft, for requiring the function name.)
 237  */
 238 #if __has_attribute(deprecated) \
 239     || PCAP_IS_AT_LEAST_GNUC_VERSION(4, 5) \
 240     || PCAP_IS_AT_LEAST_SUNC_VERSION(5, 13)
 241   /*
 242    * Compiler that supports __has_attribute and __attribute__((deprecated)),
 243    * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) or later.
 244    *
 245    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
 246    * incorrectly, that anything that supports __has_attribute() is
 247    * recent enough to support __attribute__((deprecated(msg)))).
 248    */
 249   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated(msg)))
 250 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3, 1)
 251   /*
 252    * GCC 3.1 through 4.4.
 253    *
 254    * Those support __attribute__((deprecated)) but not
 255    * __attribute__((deprecated(msg))).
 256    */
 257   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated))
 258 #elif (defined(_MSC_VER) && (_MSC_VER >= 1500)) && !defined(BUILDING_PCAP)
 259   /*
 260    * MSVC from Visual Studio 2008 or later, and we're not building
 261    * libpcap itself.
 262    *
 263    * If we *are* building libpcap, we don't want this, as it'll warn
 264    * us even if we *define* the function.
 265    */
 266   #define PCAP_DEPRECATED(func, msg)    __pragma(deprecated(func))
 267 #else
 268   #define PCAP_DEPRECATED(func, msg)
 269 #endif
 270
 271 /*
 272  * For flagging arguments as format strings in MSVC.
 273  */
 274 #if _MSC_VER >= 1400
 275  #include <sal.h>
 276  #if _MSC_VER > 1400
 277   #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 278  #else
 279   #define PCAP_FORMAT_STRING(p) __format_string p
 280  #endif
 281 #else
 282  #define PCAP_FORMAT_STRING(p) p
 283 #endif
 284
 285 #endif /* lib_pcap_funcattrs_h */