xref: /dragonfly/contrib/libpcap/pcap/funcattrs.h (revision c090269b)
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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  * 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 or
234    * later, or some compiler asserting compatibility with GCC 2.5 or
235    * later, or Solaris Studio 12 (Sun C 5.9) or later, or IBM XL C 10.1
236    * or later (do any earlier versions of XL C support this?), or HP aCC
237    * A.06.10 or 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 or later, or some compiler
264    * asserting compatibility with GCC 2.3 or 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 or later, or Sun/Oracle C 12.4 (Sun C 5.13) or 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    * or 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 */
326