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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  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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  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, so we should export functions in our
  89      * API.
  90      */
  91     #define PCAP_API_DEF        __declspec(dllexport)
  92   #elif defined(PCAP_DLL)
  93     #define PCAP_API_DEF        __declspec(dllimport)
  94   #else
  95     #define PCAP_API_DEF
  96   #endif
  97 #elif defined(MSDOS)
  98   /* XXX - does this need special treatment? */
  99   #define PCAP_API_DEF
 100 #else /* UN*X */
 101   #ifdef pcap_EXPORTS
 102     /*
 103      * We're compiling libpcap, so we should export functions in our API.
 104      * The compiler might be configured not to export functions from a
 105      * shared library by default, so we might have to explicitly mark
 106      * functions as exported.
 107      */
 108     #if PCAP_IS_AT_LEAST_GNUC_VERSION(3,4) \
 109         || PCAP_IS_AT_LEAST_XL_C_VERSION(12,0)
 110       /*
 111        * GCC 3.4 or later, or some compiler asserting compatibility with
 112        * GCC 3.4 or later, or XL C 13.0 or later, so we have
 113        * __attribute__((visibility()).
 114        */
 115       #define PCAP_API_DEF      __attribute__((visibility("default")))
 116     #elif PCAP_IS_AT_LEAST_SUNC_VERSION(5,5)
 117       /*
 118        * Sun C 5.5 or later, so we have __global.
 119        * (Sun C 5.9 and later also have __attribute__((visibility()),
 120        * but there's no reason to prefer it with Sun C.)
 121        */
 122       #define PCAP_API_DEF      __global
 123     #else
 124       /*
 125        * We don't have anything to say.
 126        */
 127       #define PCAP_API_DEF
 128     #endif
 129   #else
 130     /*
 131      * We're not building libpcap.
 132      */
 133     #define PCAP_API_DEF
 134   #endif
 135 #endif /* _WIN32/MSDOS/UN*X */
 136
 137 #define PCAP_API        PCAP_API_DEF extern
 138
 139 /*
 140  * PCAP_NORETURN, before a function declaration, means "this function
 141  * never returns".  (It must go before the function declaration, e.g.
 142  * "extern PCAP_NORETURN func(...)" rather than after the function
 143  * declaration, as the MSVC version has to go before the declaration.)
 144  */
 145 #if __has_attribute(noreturn) \
 146     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
 147     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
 148     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 149     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 150   /*
 151    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
 152    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
 153    * and later (do any earlier versions of XL C support this?), or
 154    * HP aCC A.06.10 and later.
 155    */
 156   #define PCAP_NORETURN __attribute((noreturn))
 157 #elif defined(_MSC_VER)
 158   /*
 159    * MSVC.
 160    */
 161   #define PCAP_NORETURN __declspec(noreturn)
 162 #else
 163   #define PCAP_NORETURN
 164 #endif
 165
 166 /*
 167  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
 168  * does printf-style formatting, with the xth argument being the format
 169  * string and the yth argument being the first argument for the format
 170  * string".
 171  */
 172 #if __has_attribute(__format__) \
 173     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
 174     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
 175     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
 176   /*
 177    * Compiler with support for it, or GCC 2.3 and later, or IBM XL C 10.1
 178    * and later (do any earlier versions of XL C support this?),
 179    * or HP aCC A.06.10 and later.
 180    */
 181   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
 182 #else
 183   #define PCAP_PRINTFLIKE(x,y)
 184 #endif
 185
 186 /*
 187  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
 188  * function as deprecated.
 189  *
 190  * The first argument is the name of the function; the second argument is
 191  * a string giving the warning message to use if the compiler supports that.
 192  *
 193  * (Thank you, Microsoft, for requiring the function name.)
 194  */
 195 #if __has_attribute(deprecated) \
 196     || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
 197     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
 198   /*
 199    * Compiler that supports __has_attribute and __attribute__((deprecated)),
 200    * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) or later.
 201    *
 202    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
 203    * incorrectly, that anything that supports __has_attribute() is
 204    * recent enough to support __attribute__((deprecated(msg)))).
 205    */
 206   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated(msg)))
 207 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
 208   /*
 209    * GCC 3.1 through 4.4.
 210    *
 211    * Those support __attribute__((deprecated)) but not
 212    * __attribute__((deprecated(msg))).
 213    */
 214   #define PCAP_DEPRECATED(func, msg)    __attribute__((deprecated))
 215 #elif (defined(_MSC_VER) && (_MSC_VER >= 1500)) && !defined(pcap_EXPORTS)
 216   /*
 217    * MSVC from Visual Studio 2008 or later, and we're not building
 218    * libpcap itself.
 219    *
 220    * If we *are* building libpcap, we don't want this, as it'll warn
 221    * us even if we *define* the function.
 222    */
 223   #define PCAP_DEPRECATED(func, msg)    __pragma(deprecated(func))
 224 #else
 225   #define PCAP_DEPRECATED(func, msg)
 226 #endif
 227
 228 /*
 229  * For flagging arguments as format strings in MSVC.
 230  */
 231 #ifdef _MSC_VER
 232  #include <sal.h>
 233  #if _MSC_VER > 1400
 234   #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 235  #else
 236   #define PCAP_FORMAT_STRING(p) __format_string p
 237  #endif
 238 #else
 239  #define PCAP_FORMAT_STRING(p) p
 240 #endif
 241
 242 #endif /* lib_pcap_funcattrs_h */