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  *
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   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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  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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  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 #include <pcap/compiler-tests.h>
  39
  40 /*
  41  * Attributes to apply to functions and their arguments, using various
  42  * compiler-specific extensions.
  43  */
  44
  45 /*
  46  * PCAP_API_DEF must be used when defining *data* exported from
  47  * libpcap.  It can be used when defining *functions* exported
  48  * from libpcap, but it doesn't have to be used there.  It
  49  * should not be used in declarations in headers.
  50  *
  51  * PCAP_API must be used when *declaring* data or functions
  52  * exported from libpcap; PCAP_API_DEF won't work on all platforms.
  53  */
  54
  55 #if defined(_WIN32)
  56   /*
  57    * For Windows:
  58    *
  59    *    when building libpcap:
  60    *
  61    *       if we're building it as a DLL, we have to declare API
  62    *       functions with __declspec(dllexport);
  63    *
  64    *       if we're building it as a static library, we don't want
  65    *       to do so.
  66    *
  67    *    when using libpcap:
  68    *
  69    *       if we're using the DLL, calls to its functions are a
  70    *       little more efficient if they're declared with
  71    *       __declspec(dllimport);
  72    *
  73    *       if we're not using the dll, we don't want to declare
  74    *       them that way.
  75    *
  76    * So:
  77    *
  78    *    if pcap_EXPORTS is defined, we define PCAP_API_DEF as
  79    *     __declspec(dllexport);
  80    *
  81    *    if PCAP_DLL is defined, we define PCAP_API_DEF as
  82    *    __declspec(dllimport);
  83    *
  84    *    otherwise, we define PCAP_API_DEF as nothing.
  85    */
  86   #if defined(pcap_EXPORTS)
  87     /*
  88      * We're compiling libpcap as a DLL, so we should export functions
  89      * in our API.
  90      */
  91     #define PCAP_API_DEF        __declspec(dllexport)
  92   #elif defined(PCAP_DLL)
  93     /*
  94      * We're using libpcap as a DLL, so the calls will be a little more
  95      * efficient if we explicitly import the functions.
  96      */
  97     #define PCAP_API_DEF        __declspec(dllimport)
  98   #else
  99     /*
 100      * Either we're building libpcap as a static library, or we're using
 101      * it as a static library, or we don't know for certain that we're
 102      * using it as a dynamic library, so neither import nor export the
 103      * functions explicitly.
 104      */
 105     #define PCAP_API_DEF
 106   #endif
 107 #elif defined(MSDOS)
 108   /* XXX - does this need special treatment? */
 109   #define PCAP_API_DEF
 110 #else /* UN*X */
 111   #ifdef pcap_EXPORTS
 112     /*
 113      * We're compiling libpcap as a (dynamic) shared library, so we should
 114      * export functions in our API.  The compiler might be configured not
 115      * to export functions from a shared library by default, so we might
 116      * have to explicitly mark functions as exported.
 117      */
 118     #if PCAP_IS_AT_LEAST_GNUC_VERSION(3,4) \
 119         || PCAP_IS_AT_LEAST_XL_C_VERSION(12,0)
 120       /*
 121        * GCC 3.4 and later, or some compiler asserting compatibility with
 122        * GCC 3.4 and later, or XL C 13.0 and later, so we have
 123        * __attribute__((visibility()).
 124        */
 125       #define PCAP_API_DEF      __attribute__((visibility("default")))
 126     #elif PCAP_IS_AT_LEAST_SUNC_VERSION(5,5)
 127       /*
 128        * Sun C 5.5 and later, so we have __global.
 129        * (Sun C 5.9 and later also have __attribute__((visibility()),
 130        * but there's no reason to prefer it with Sun C.)
 131        */
 132       #define PCAP_API_DEF      __global
 133     #else
 134       /*
 135        * We don't have anything to say.
 136        */
 137       #define PCAP_API_DEF
 138     #endif
 139   #else
 140     /*
 141      * We're not building libpcap.
 142      */
 143     #define PCAP_API_DEF
 144   #endif
 145 #endif /* _WIN32/MSDOS/UN*X */
 146
 147 #define PCAP_API        PCAP_API_DEF extern
 148
 149 /*
 150  * Definitions to 1) indicate what version of libpcap first had a given
 151  * API and 2) allow upstream providers whose build environments allow
 152  * APIs to be designated as "first available in this release" to do so
 153  * by appropriately defining them.
 154  *
 155  * Yes, that's you, Apple. :-)  Please define PCAP_AVAILABLE_MACOS()
 156  * as necessary to make various APIs "weak exports" to make it easier
 157  * for software that's distributed in binary form and that uses libpcap
 158  * to run on multiple macOS versions and use new APIs when available.
 159  * (Yes, such third-party software exists - Wireshark provides binary
 160  * packages for macOS, for example.  tcpdump doesn't count, as that's
 161  * provided by Apple, so each release can come with a version compiled
 162  * to use the APIs present in that release.)
 163  *
 164  * The non-macOS versioning is based on
 165  *
 166  *    https://en.wikipedia.org/wiki/Darwin_(operating_system)#Release_history
 167  *
 168  * If there are any corrections, please submit it upstream to the
 169  * libpcap maintainers, preferably as a pull request on
 170  *
 171  *    https://github.com/the-tcpdump-group/libpcap
 172  *
 173  * We don't define it ourselves because, if you're building and
 174  * installing libpcap on macOS yourself, the APIs will be available
 175  * no matter what OS version you're installing it on.
 176  *
 177  * For other platforms, we don't define them, leaving it up to
 178  * others to do so based on their OS versions, if appropriate.
 179  *
 180  * We start with libpcap 0.4, as that was the last LBL release, and
 181  * I've never seen earlier releases.
 182  */
 183 #ifdef __APPLE__
 184 #include <Availability.h>
 185 /*
 186  * When building as part of macOS, define this as __API_AVAILABLE(__VA_ARGS__).
 187  *
 188  * XXX - if there's some #define to indicate that this is being built
 189  * as part of the macOS build process, we could make that Just Work.
 190  */
 191 #define PCAP_AVAILABLE(...)
 192 #define PCAP_AVAILABLE_0_4      PCAP_AVAILABLE(macos(10.0)) /* Did any version of Mac OS X ship with this? */
 193 #define PCAP_AVAILABLE_0_5      PCAP_AVAILABLE(macos(10.0)) /* Did any version of Mac OS X ship with this? */
 194 #define PCAP_AVAILABLE_0_6      PCAP_AVAILABLE(macos(10.1))
 195 #define PCAP_AVAILABLE_0_7      PCAP_AVAILABLE(macos(10.4))
 196 #define PCAP_AVAILABLE_0_8      PCAP_AVAILABLE(macos(10.4))
 197 #define PCAP_AVAILABLE_0_9      PCAP_AVAILABLE(macos(10.5), ios(1.0))
 198 #define PCAP_AVAILABLE_1_0      PCAP_AVAILABLE(macos(10.6), ios(4.0))
 199 /* #define PCAP_AVAILABLE_1_1   no routines added to the API */
 200 #define PCAP_AVAILABLE_1_2      PCAP_AVAILABLE(macos(10.9), ios(6.0))
 201 /* #define PCAP_AVAILABLE_1_3   no routines added to the API */
 202 /* #define PCAP_AVAILABLE_1_4   no routines added to the API */
 203 #define PCAP_AVAILABLE_1_5      PCAP_AVAILABLE(macos(10.10), ios(7.0), watchos(1.0))
 204 /* #define PCAP_AVAILABLE_1_6   no routines added to the API */
 205 #define PCAP_AVAILABLE_1_7      PCAP_AVAILABLE(macos(10.12), ios(10.0), tvos(10.0), watchos(3.0))
 206 #define PCAP_AVAILABLE_1_8      PCAP_AVAILABLE(macos(10.13), ios(11.0), tvos(11.0), watchos(4.0)) /* only Windows adds routines to the API; XXX - what version first had it? */
 207 #define PCAP_AVAILABLE_1_9      PCAP_AVAILABLE(macos(10.13), ios(11.0), tvos(11.0), watchos(4.0))
 208 #define PCAP_AVAILABLE_1_10     /* not in macOS yet */
 209 #define PCAP_AVAILABLE_1_11     /* not released yet, so not in macOS yet */
 210 #else /* __APPLE__ */
 211 #define PCAP_AVAILABLE_0_4
 212 #define PCAP_AVAILABLE_0_5
 213 #define PCAP_AVAILABLE_0_6
 214 #define PCAP_AVAILABLE_0_7
 215 #define PCAP_AVAILABLE_0_8
 216 #define PCAP_AVAILABLE_0_9
 217 #define PCAP_AVAILABLE_1_0
 218 /* #define PCAP_AVAILABLE_1_1   no routines added to the API */
 219 #define PCAP_AVAILABLE_1_2
 220 /* #define PCAP_AVAILABLE_1_3   no routines added to the API */
 221 /* #define PCAP_AVAILABLE_1_4   no routines added to the API */
 222 #define PCAP_AVAILABLE_1_5
 223 /* #define PCAP_AVAILABLE_1_6   no routines added to the API */
 224 #define PCAP_AVAILABLE_1_7
 225 #define PCAP_AVAILABLE_1_8
 226 #define PCAP_AVAILABLE_1_9
 227 #define PCAP_AVAILABLE_1_10
 228 #define PCAP_AVAILABLE_1_11
 229 #endif /* __APPLE__ */
 230
 231 /*
 232  * PCAP_NORETURN, before a function declaration, means "this function
 233  * never returns".  (It must go before the function declaration, e.g.
 234  * "extern PCAP_NORETURN func(...)" rather than after the function
 235  * declaration, as the MSVC version has to go before the declaration.)
 236  *
 237  * PCAP_NORETURN_DEF, before a function *definition*, means "this
 238  * function never returns"; it would be used only for static functions
 239  * that are defined before any use, and thus have no declaration.
 240  * (MSVC doesn't support that; I guess the "decl" in "__declspec"
 241  * means "declaration", and __declspec doesn't work with definitions.)
 242  */
 243 #if __has_attribute(noreturn) \
 244     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
 245     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
 246     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 247     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 248   /*
 249    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
 250    * later, or some compiler asserting compatibility with GCC 2.5 and
 251    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
 252    * and later (do any earlier versions of XL C support this?), or HP aCC
 253    * A.06.10 and later.
 254    */
 255   #define PCAP_NORETURN __attribute((noreturn))
 256   #define PCAP_NORETURN_DEF __attribute((noreturn))
 257 #elif defined(_MSC_VER)
 258   /*
 259    * MSVC.
 260    */
 261   #define PCAP_NORETURN __declspec(noreturn)
 262   #define PCAP_NORETURN_DEF
 263 #else
 264   #define PCAP_NORETURN
 265   #define PCAP_NORETURN_DEF
 266 #endif
 267
 268 /*
 269  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
 270  * does printf-style formatting, with the xth argument being the format
 271  * string and the yth argument being the first argument for the format
 272  * string".
 273  */
 274 #if __has_attribute(__format__) \
 275     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
 276     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 277     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 278   /*
 279    * Compiler with support for it, or GCC 2.3 and later, or some compiler
 280    * asserting compatibility with GCC 2.3 and later, or IBM XL C 10.1
 281    * and later (do any earlier versions of XL C support this?),
 282    * or HP aCC A.06.10 and later.
 283    */
 284   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
 285 #else
 286   #define PCAP_PRINTFLIKE(x,y)
 287 #endif
 288
 289 /*
 290  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
 291  * function as deprecated.
 292  *
 293  * The argument is a string giving the warning message to use if the
 294  * compiler supports that.
 295  */
 296 #if __has_attribute(deprecated) \
 297     || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
 298     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
 299   /*
 300    * Compiler that supports __has_attribute and __attribute__((deprecated)),
 301    * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) and later.
 302    *
 303    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
 304    * incorrectly, that anything that supports __has_attribute() is
 305    * recent enough to support __attribute__((deprecated(msg)))).
 306    */
 307   #define PCAP_DEPRECATED(msg)  __attribute__((deprecated(msg)))
 308 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
 309   /*
 310    * GCC 3.1 through 4.4.
 311    *
 312    * Those support __attribute__((deprecated)) but not
 313    * __attribute__((deprecated(msg))).
 314    */
 315   #define PCAP_DEPRECATED(msg)  __attribute__((deprecated))
 316 #elif defined(_MSC_VER) && !defined(BUILDING_PCAP)
 317   /*
 318    * MSVC, and we're not building libpcap itself; it's VS 2015
 319    * and later, so we have the deprecated pragma.
 320    *
 321    * If we *are* building libpcap, we don't want this, as it'll warn
 322    * us even if we *define* the function.
 323    */
 324   #define PCAP_DEPRECATED(msg)  _declspec(deprecated(msg))
 325 #else
 326   #define PCAP_DEPRECATED(msg)
 327 #endif
 328
 329 /*
 330  * For flagging arguments as format strings in MSVC.
 331  */
 332 #ifdef _MSC_VER
 333  #include <sal.h>
 334  #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 335 #else
 336  #define PCAP_FORMAT_STRING(p) p
 337 #endif
 338
 339 #endif /* lib_pcap_funcattrs_h */