libpcap  1.10.1
About: libpcap is a packet filter library used by tools like tcpdump.
  Fossies Dox: libpcap-1.10.1.tar.gz  ("unofficial" and yet experimental doxygen-generated source code documentation)  

funcattrs.h
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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 */