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
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   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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  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  * We don't define it ourselves because, if you're building and
 165  * installing libpcap on macOS yourself, the APIs will be available
 166  * no matter what OS version you're installing it on.
 167  *
 168  * For other platforms, we don't define them, leaving it up to
 169  * others to do so based on their OS versions, if appropriate.
 170  *
 171  * We start with libpcap 0.4, as that was the last LBL release, and
 172  * I've never seen earlier releases.
 173  */
 174 #ifdef __APPLE__
 175 #define PCAP_AVAILABLE_MACOS(v) /* define to say "first appears in v" */
 176 #define PCAP_AVAILABLE_0_4      PCAP_AVAILABLE_MACOS(10.0) /* Did any version of Mac OS X ship with this? */
 177 #define PCAP_AVAILABLE_0_5      PCAP_AVAILABLE_MACOS(10.0) /* Did any version of Mac OS X ship with this? */
 178 #define PCAP_AVAILABLE_0_6      PCAP_AVAILABLE_MACOS(10.1)
 179 #define PCAP_AVAILABLE_0_7      PCAP_AVAILABLE_MACOS(10.4)
 180 #define PCAP_AVAILABLE_0_8      PCAP_AVAILABLE_MACOS(10.4)
 181 #define PCAP_AVAILABLE_0_9      PCAP_AVAILABLE_MACOS(10.5)
 182 #define PCAP_AVAILABLE_1_0      PCAP_AVAILABLE_MACOS(10.6)
 183 /* #define PCAP_AVAILABLE_1_1   no routines added to the API */
 184 #define PCAP_AVAILABLE_1_2      PCAP_AVAILABLE_MACOS(10.9)
 185 /* #define PCAP_AVAILABLE_1_3   no routines added to the API */
 186 /* #define PCAP_AVAILABLE_1_4   no routines added to the API */
 187 #define PCAP_AVAILABLE_1_5      PCAP_AVAILABLE_MACOS(10.10)
 188 /* #define PCAP_AVAILABLE_1_6   no routines added to the API */
 189 #define PCAP_AVAILABLE_1_7      PCAP_AVAILABLE_MACOS(10.12)
 190 #define PCAP_AVAILABLE_1_8      PCAP_AVAILABLE_MACOS(10.13) /* only Windows adds routines to the API; XXX - what version first had it? */
 191 #define PCAP_AVAILABLE_1_9      PCAP_AVAILABLE_MACOS(10.13)
 192 #define PCAP_AVAILABLE_1_10     /* not in macOS yet */
 193 #define PCAP_AVAILABLE_1_11     /* not released yet, so not in macOS yet */
 194 #else /* __APPLE__ */
 195 #define PCAP_AVAILABLE_0_4
 196 #define PCAP_AVAILABLE_0_5
 197 #define PCAP_AVAILABLE_0_6
 198 #define PCAP_AVAILABLE_0_7
 199 #define PCAP_AVAILABLE_0_8
 200 #define PCAP_AVAILABLE_0_9
 201 #define PCAP_AVAILABLE_1_0
 202 /* #define PCAP_AVAILABLE_1_1   no routines added to the API */
 203 #define PCAP_AVAILABLE_1_2
 204 /* #define PCAP_AVAILABLE_1_3   no routines added to the API */
 205 /* #define PCAP_AVAILABLE_1_4   no routines added to the API */
 206 #define PCAP_AVAILABLE_1_5
 207 /* #define PCAP_AVAILABLE_1_6   no routines added to the API */
 208 #define PCAP_AVAILABLE_1_7
 209 #define PCAP_AVAILABLE_1_8
 210 #define PCAP_AVAILABLE_1_9
 211 #define PCAP_AVAILABLE_1_10
 212 #define PCAP_AVAILABLE_1_11
 213 #endif /* __APPLE__ */
 214
 215 /*
 216  * PCAP_NORETURN, before a function declaration, means "this function
 217  * never returns".  (It must go before the function declaration, e.g.
 218  * "extern PCAP_NORETURN func(...)" rather than after the function
 219  * declaration, as the MSVC version has to go before the declaration.)
 220  *
 221  * PCAP_NORETURN_DEF, before a function *definition*, means "this
 222  * function never returns"; it would be used only for static functions
 223  * that are defined before any use, and thus have no declaration.
 224  * (MSVC doesn't support that; I guess the "decl" in "__declspec"
 225  * means "declaration", and __declspec doesn't work with definitions.)
 226  */
 227 #if __has_attribute(noreturn) \
 228     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
 229     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
 230     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 231     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 232   /*
 233    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
 234    * later, or some compiler asserting compatibility with GCC 2.5 and
 235    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
 236    * and later (do any earlier versions of XL C support this?), or HP aCC
 237    * A.06.10 and later.
 238    */
 239   #define PCAP_NORETURN __attribute((noreturn))
 240   #define PCAP_NORETURN_DEF __attribute((noreturn))
 241 #elif defined(_MSC_VER)
 242   /*
 243    * MSVC.
 244    */
 245   #define PCAP_NORETURN __declspec(noreturn)
 246   #define PCAP_NORETURN_DEF
 247 #else
 248   #define PCAP_NORETURN
 249   #define PCAP_NORETURN_DEF
 250 #endif
 251
 252 /*
 253  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
 254  * does printf-style formatting, with the xth argument being the format
 255  * string and the yth argument being the first argument for the format
 256  * string".
 257  */
 258 #if __has_attribute(__format__) \
 259     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
 260     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 261     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 262   /*
 263    * Compiler with support for it, or GCC 2.3 and later, or some compiler
 264    * asserting compatibility with GCC 2.3 and later, or IBM XL C 10.1
 265    * and later (do any earlier versions of XL C support this?),
 266    * or HP aCC A.06.10 and later.
 267    */
 268   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
 269 #else
 270   #define PCAP_PRINTFLIKE(x,y)
 271 #endif
 272
 273 /*
 274  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
 275  * function as deprecated.
 276  *
 277  * The first argument is the name of the function; the second argument is
 278  * a string giving the warning message to use if the compiler supports that.
 279  *
 280  * (Thank you, Microsoft, for requiring the function name.)
 281  */
 282 #if __has_attribute(deprecated) \
 283     || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
 284     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
 285   /*
 286    * Compiler that supports __has_attribute and __attribute__((deprecated)),
 287    * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) and later.
 288    *
 289    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
 290    * incorrectly, that anything that supports __has_attribute() is
 291    * recent enough to support __attribute__((deprecated(msg)))).
 292    */
 293   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated(msg)))
 294 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
 295   /*
 296    * GCC 3.1 through 4.4.
 297    *
 298    * Those support __attribute__((deprecated)) but not
 299    * __attribute__((deprecated(msg))).
 300    */
 301   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated))
 302 #elif defined(_MSC_VER) && !defined(BUILDING_PCAP)
 303   /*
 304    * MSVC, and we're not building libpcap itself; it's VS 2015
 305    * and later, so we have the deprecated pragma.
 306    *
 307    * If we *are* building libpcap, we don't want this, as it'll warn
 308    * us even if we *define* the function.
 309    */
 310   #define PCAP_DEPRECATED(func, msg)    __pragma(deprecated(func))
 311 #else
 312   #define PCAP_DEPRECATED(func, msg)
 313 #endif
 314
 315 /*
 316  * For flagging arguments as format strings in MSVC.
 317  */
 318 #ifdef _MSC_VER
 319  #include <sal.h>
 320  #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 321 #else
 322  #define PCAP_FORMAT_STRING(p) p
 323 #endif
 324
 325 #endif /* lib_pcap_funcattrs_h */