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3  * Copyright (c) 1993, 1994, 1995, 1996, 1997
4  *	The Regents of the University of California.  All rights reserved.
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10  *    notice, this list of conditions and the following disclaimer.
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16  *	This product includes software developed by the Computer Systems
17  *	Engineering Group at Lawrence Berkeley Laboratory.
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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  * PCAP_NORETURN_DEF, before a function *definition*, means "this
156  * function never returns"; it would be used only for static functions
157  * that are defined before any use, and thus have no declaration.
158  * (MSVC doesn't support that; I guess the "decl" in "__declspec"
159  * means "declaration", and __declspec doesn't work with definitions.)
160  */
161 #if __has_attribute(noreturn) \
162     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
163     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
164     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
165     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
166   /*
167    * Compiler with support for __attribute((noreturn)), or GCC 2.5 or
168    * later, or some compiler asserting compatibility with GCC 2.5 or
169    * later, or Solaris Studio 12 (Sun C 5.9) or later, or IBM XL C 10.1
170    * or later (do any earlier versions of XL C support this?), or HP aCC
171    * A.06.10 or later.
172    */
173   #define PCAP_NORETURN __attribute((noreturn))
174   #define PCAP_NORETURN_DEF __attribute((noreturn))
175 #elif defined(_MSC_VER)
176   /*
177    * MSVC.
178    */
179   #define PCAP_NORETURN __declspec(noreturn)
180   #define PCAP_NORETURN_DEF
181 #else
182   #define PCAP_NORETURN
183   #define PCAP_NORETURN_DEF
184 #endif
185 
186 /*
187  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
188  * does printf-style formatting, with the xth argument being the format
189  * string and the yth argument being the first argument for the format
190  * string".
191  */
192 #if __has_attribute(__format__) \
193     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
194     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
195     || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
196   /*
197    * Compiler with support for it, or GCC 2.3 or later, or some compiler
198    * asserting compatibility with GCC 2.3 or later, or IBM XL C 10.1
199    * and later (do any earlier versions of XL C support this?),
200    * or HP aCC A.06.10 and later.
201    */
202   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
203 #else
204   #define PCAP_PRINTFLIKE(x,y)
205 #endif
206 
207 /*
208  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
209  * function as deprecated.
210  *
211  * The first argument is the name of the function; the second argument is
212  * a string giving the warning message to use if the compiler supports that.
213  *
214  * (Thank you, Microsoft, for requiring the function name.)
215  */
216 #if __has_attribute(deprecated) \
217     || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
218     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
219   /*
220    * Compiler that supports __has_attribute and __attribute__((deprecated)),
221    * or GCC 4.5 or later, or Sun/Oracle C 12.4 (Sun C 5.13) or later.
222    *
223    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
224    * incorrectly, that anything that supports __has_attribute() is
225    * recent enough to support __attribute__((deprecated(msg)))).
226    */
227   #define PCAP_DEPRECATED(func, msg)	__attribute__((deprecated(msg)))
228 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
229   /*
230    * GCC 3.1 through 4.4.
231    *
232    * Those support __attribute__((deprecated)) but not
233    * __attribute__((deprecated(msg))).
234    */
235   #define PCAP_DEPRECATED(func, msg)	__attribute__((deprecated))
236 #elif (defined(_MSC_VER) && (_MSC_VER >= 1500)) && !defined(BUILDING_PCAP)
237   /*
238    * MSVC from Visual Studio 2008 or later, and we're not building
239    * libpcap itself.
240    *
241    * If we *are* building libpcap, we don't want this, as it'll warn
242    * us even if we *define* the function.
243    */
244   #define PCAP_DEPRECATED(func, msg)	__pragma(deprecated(func))
245 #else
246   #define PCAP_DEPRECATED(func, msg)
247 #endif
248 
249 /*
250  * For flagging arguments as format strings in MSVC.
251  */
252 #ifdef _MSC_VER
253  #include <sal.h>
254  #if _MSC_VER > 1400
255   #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
256  #else
257   #define PCAP_FORMAT_STRING(p) __format_string p
258  #endif
259 #else
260  #define PCAP_FORMAT_STRING(p) p
261 #endif
262 
263 #endif /* lib_pcap_funcattrs_h */
264