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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   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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  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 or later, or some compiler asserting compatibility with
 122        * GCC 3.4 or later, or XL C 13.0 or 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 or 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  * PCAP_NORETURN, before a function declaration, means "this function
 151  * never returns".  (It must go before the function declaration, e.g.
 152  * "extern PCAP_NORETURN func(...)" rather than after the function
 153  * declaration, as the MSVC version has to go before the declaration.)
 154  */
 155 #if __has_attribute(noreturn) \
 156     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
 157     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
 158     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 159     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 160   /*
 161    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
 162    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
 163    * and later (do any earlier versions of XL C support this?), or
 164    * HP aCC A.06.10 and later.
 165    */
 166   #define PCAP_NORETURN __attribute((noreturn))
 167 #elif defined(_MSC_VER)
 168   /*
 169    * MSVC.
 170    */
 171   #define PCAP_NORETURN __declspec(noreturn)
 172 #else
 173   #define PCAP_NORETURN
 174 #endif
 175
 176 /*
 177  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
 178  * does printf-style formatting, with the xth argument being the format
 179  * string and the yth argument being the first argument for the format
 180  * string".
 181  */
 182 #if __has_attribute(__format__) \
 183     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
 184     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 185     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 186   /*
 187    * Compiler with support for it, or GCC 2.3 and later, or IBM XL C 10.1
 188    * and later (do any earlier versions of XL C support this?),
 189    * or HP aCC A.06.10 and later.
 190    */
 191   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
 192 #else
 193   #define PCAP_PRINTFLIKE(x,y)
 194 #endif
 195
 196 /*
 197  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
 198  * function as deprecated.
 199  *
 200  * The first argument is the name of the function; the second argument is
 201  * a string giving the warning message to use if the compiler supports that.
 202  *
 203  * (Thank you, Microsoft, for requiring the function name.)
 204  */
 205 #if __has_attribute(deprecated) \
 206     || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
 207     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
 208   /*
 209    * Compiler that supports __has_attribute and __attribute__((deprecated)),
 210    * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) or later.
 211    *
 212    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
 213    * incorrectly, that anything that supports __has_attribute() is
 214    * recent enough to support __attribute__((deprecated(msg)))).
 215    */
 216   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated(msg)))
 217 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
 218   /*
 219    * GCC 3.1 through 4.4.
 220    *
 221    * Those support __attribute__((deprecated)) but not
 222    * __attribute__((deprecated(msg))).
 223    */
 224   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated))
 225 #elif (defined(_MSC_VER) && (_MSC_VER >= 1500)) && !defined(BUILDING_PCAP)
 226   /*
 227    * MSVC from Visual Studio 2008 or later, and we're not building
 228    * libpcap itself.
 229    *
 230    * If we *are* building libpcap, we don't want this, as it'll warn
 231    * us even if we *define* the function.
 232    */
 233   #define PCAP_DEPRECATED(func, msg)    __pragma(deprecated(func))
 234 #else
 235   #define PCAP_DEPRECATED(func, msg)
 236 #endif
 237
 238 /*
 239  * For flagging arguments as format strings in MSVC.
 240  */
 241 #ifdef _MSC_VER
 242  #include <sal.h>
 243  #if _MSC_VER > 1400
 244   #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 245  #else
 246   #define PCAP_FORMAT_STRING(p) __format_string p
 247  #endif
 248 #else
 249  #define PCAP_FORMAT_STRING(p) p
 250 #endif
 251
 252 #endif /* lib_pcap_funcattrs_h */