Document that wxTrap() now traps [almost] always.
[wxWidgets.git] / interface / wx / debug.h
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: wx/debug.h
3 // Purpose: interface of global functions
4 // Author: wxWidgets team
5 // RCS-ID: $Id$
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
8
9 /** @addtogroup group_funcmacro_debug */
10 //@{
11
12 /**
13 @def wxDEBUG_LEVEL
14
15 Preprocessor symbol defining the level of debug support available.
16
17 This symbol is defined to 1 by default meaning that asserts are compiled in
18 (although they may be disabled by a call to wxDisableAsserts()). You may
19 predefine it as 0 prior to including any wxWidgets headers to omit the
20 calls to wxASSERT() and related macros entirely in your own code and you
21 may also predefine it as 0 when building wxWidgets to also avoid including
22 any asserts in wxWidgets itself.
23
24 Alternatively, you may predefine it as 2 to include wxASSERT_LEVEL_2() and
25 similar macros which are used for asserts which have non-trivial run-time
26 costs and so are disabled by default.
27
28 @since 2.9.1
29
30 @header{wx/debug.h}
31 */
32 #define wxDEBUG_LEVEL
33
34 /**
35 @def __WXDEBUG__
36
37 Compatibility macro indicating presence of debug support.
38
39 This symbol is defined if wxDEBUG_LEVEL is greater than 0 and undefined
40 otherwise.
41
42 @header{wx/debug.h}
43 */
44 #define __WXDEBUG__
45
46 /**
47 Type for the function called in case of assert failure.
48
49 @see wxSetAssertHandler()
50 */
51 typedef void (*wxAssertHandler_t)(const wxString& file,
52 int line,
53 const wxString& func,
54 const wxString& cond,
55 const wxString& msg);
56
57 /**
58 Assert macro. An error message will be generated if the condition is @false in
59 debug mode, but nothing will be done in the release build.
60
61 Please note that the condition in wxASSERT() should have no side effects
62 because it will not be executed in release mode at all.
63
64 This macro should be used to catch (in debug builds) logical errors done
65 by the programmer.
66
67 @see wxASSERT_MSG(), wxCOMPILE_TIME_ASSERT()
68
69 @header{wx/debug.h}
70 */
71 #define wxASSERT( condition )
72
73 /**
74 Assert macro for expensive run-time checks.
75
76 This macro does nothing unless wxDEBUG_LEVEL is 2 or more and is meant to
77 be used for the assertions with noticeable performance impact and which,
78 hence, should be disabled during run-time.
79
80 If wxDEBUG_LEVEL is 2 or more, it becomes the same as wxASSERT().
81
82 @header{wx/debug.h}
83 */
84 #define wxASSERT_LEVEL_2( condition )
85
86 /**
87 Assert macro with a custom message for expensive run-time checks.
88
89 If wxDEBUG_LEVEL is 2 or more, this is the same as wxASSERT_MSG(),
90 otherwise it doesn't do anything at all.
91
92 @see wxASSERT_LEVEL_2()
93
94 @header{wx/debug.h}
95 */
96 #define wxASSERT_LEVEL_2_MSG( condition, msg)
97
98
99 /**
100 This macro results in a @ref wxCOMPILE_TIME_ASSERT "compile time assertion failure"
101 if the size of the given @c type is less than @c size bits.
102
103 This macro should be used to catch (in debug builds) logical errors done
104 by the programmer.
105
106 You may use it like this, for example:
107
108 @code
109 // we rely on the int being able to hold values up to 2^32
110 wxASSERT_MIN_BITSIZE(int, 32);
111
112 // can't work with the platforms using UTF-8 for wchar_t
113 wxASSERT_MIN_BITSIZE(wchar_t, 16);
114 @endcode
115
116 @header{wx/debug.h}
117 */
118 #define wxASSERT_MIN_BITSIZE( type, size )
119
120 /**
121 Assert macro with message.
122 An error message will be generated if the condition is @false.
123
124 This macro should be used to catch (in debug builds) logical errors done
125 by the programmer.
126
127 @see wxASSERT(), wxCOMPILE_TIME_ASSERT()
128
129 @header{wx/debug.h}
130 */
131 #define wxASSERT_MSG( condition, message )
132
133 /**
134 Checks that the condition is @true, returns with the given return value if
135 not (stops execution in debug mode). This check is done even in release mode.
136
137 This macro should be used to catch (both in debug and release builds) logical
138 errors done by the programmer.
139
140 @header{wx/debug.h}
141 */
142 #define wxCHECK( condition, retValue )
143
144 /**
145 Checks that the condition is @true, returns with the given return value if
146 not (stops execution in debug mode). This check is done even in release mode.
147
148 This macro may be only used in non-void functions, see also wxCHECK_RET().
149
150 This macro should be used to catch (both in debug and release builds) logical
151 errors done by the programmer.
152
153 @header{wx/debug.h}
154 */
155 #define wxCHECK_MSG( condition, retValue, message )
156
157 /**
158 Checks that the condition is @true, and returns if not (stops execution
159 with the given error message in debug mode). This check is done even in
160 release mode.
161
162 This macro should be used in void functions instead of wxCHECK_MSG().
163
164 This macro should be used to catch (both in debug and release builds) logical
165 errors done by the programmer.
166
167 @header{wx/debug.h}
168 */
169 #define wxCHECK_RET( condition, message )
170
171 /**
172 Checks that the condition is @true, and if not, it will wxFAIL() and
173 execute the given @c operation if it is not. This is a generalisation of
174 wxCHECK() and may be used when something else than just returning from the
175 function must be done when the @c condition is @false. This check is done
176 even in release mode.
177
178 This macro should be used to catch (both in debug and release builds) logical
179 errors done by the programmer.
180
181 @header{wx/debug.h}
182 */
183 #define wxCHECK2(condition, operation)
184
185 /**
186 This is the same as wxCHECK2(), but wxFAIL_MSG() with the specified
187 @c message is called instead of wxFAIL() if the @c condition is @false.
188
189 This macro should be used to catch (both in debug and release builds) logical
190 errors done by the programmer.
191
192 @header{wx/debug.h}
193 */
194 #define wxCHECK2_MSG( condition, operation, message )
195
196 /**
197 Using wxCOMPILE_TIME_ASSERT() results in a compilation error if the
198 specified @c condition is @false. The compiler error message should include
199 the @c message identifier - please note that it must be a valid C++
200 identifier and not a string unlike in the other cases.
201
202 This macro is mostly useful for testing the expressions involving the
203 @c sizeof operator as they can't be tested by the preprocessor but it is
204 sometimes desirable to test them at the compile time.
205
206 Note that this macro internally declares a struct whose name it tries to
207 make unique by using the @c __LINE__ in it but it may still not work if you
208 use it on the same line in two different source files. In this case you may
209 either change the line in which either of them appears on or use the
210 wxCOMPILE_TIME_ASSERT2() macro.
211
212 Also note that Microsoft Visual C++ has a bug which results in compiler
213 errors if you use this macro with 'Program Database For Edit And Continue'
214 (@c /ZI) option, so you shouldn't use it ('Program Database' (@c /Zi) is ok
215 though) for the code making use of this macro.
216
217 This macro should be used to catch misconfigurations at compile-time.
218
219 @see wxASSERT_MSG(), wxASSERT_MIN_BITSIZE()
220
221 @header{wx/debug.h}
222 */
223 #define wxCOMPILE_TIME_ASSERT( condition, message )
224
225 /**
226 This macro is identical to wxCOMPILE_TIME_ASSERT() except that it allows
227 you to specify a unique @c name for the struct internally defined by this
228 macro to avoid getting the compilation errors described for
229 wxCOMPILE_TIME_ASSERT().
230
231 This macro should be used to catch misconfigurations at compile-time.
232
233 @header{wx/debug.h}
234 */
235 #define wxCOMPILE_TIME_ASSERT2(condition, message, name)
236
237 /**
238 Disable the condition checks in the assertions.
239
240 This is the same as calling wxSetAssertHandler() with @NULL handler.
241
242 @since 2.9.0
243
244 @header{wx/debug.h}
245 */
246 void wxDisableAsserts();
247
248 /**
249 @def wxDISABLE_ASSERTS_IN_RELEASE_BUILD
250
251 Use this macro to disable asserts in release build when not using
252 IMPLEMENT_APP().
253
254 By default, assert message boxes are suppressed in release build by
255 IMPLEMENT_APP() which uses this macro. If you don't use IMPLEMENT_APP()
256 because your application initializes wxWidgets directly (e.g. calls
257 wxEntry() or wxEntryStart() itself) but still want to suppress assert
258 notifications in release build you need to use this macro directly.
259
260 @see wxDISABLE_DEBUG_SUPPORT()
261
262 @since 2.9.1
263
264 @header{wx/debug.h}
265 */
266 #define wxDISABLE_ASSERTS_IN_RELEASE_BUILD() wxDisableAsserts()
267
268 /**
269 Will always generate an assert error if this code is reached (in debug mode).
270 Note that you don't have to (and cannot) use brackets when invoking this
271 macro:
272
273 @code
274 if (...some condition...) {
275 wxFAIL;
276 }
277 @endcode
278
279 This macro should be used to catch (in debug builds) logical errors done
280 by the programmer.
281
282 @see wxFAIL_MSG()
283
284 @header{wx/debug.h}
285 */
286 #define wxFAIL
287
288 /**
289 Will always generate an assert error with specified message if this code is
290 reached (in debug mode).
291
292 This macro is useful for marking unreachable" code areas, for example it
293 may be used in the "default:" branch of a switch statement if all possible
294 cases are processed above.
295
296 This macro should be used to catch (in debug builds) logical errors done
297 by the programmer.
298
299 @see wxFAIL()
300
301 @header{wx/debug.h}
302 */
303 #define wxFAIL_MSG( message )
304
305 /**
306 Returns @true if the program is running under debugger, @false otherwise.
307
308 Please note that this function is currently only implemented for Win32 and
309 Mac builds using CodeWarrior and always returns @false elsewhere.
310
311 @header{wx/debug.h}
312 */
313 bool wxIsDebuggerRunning();
314
315 /**
316 Sets the function to be called in case of assertion failure.
317
318 The default assert handler forwards to wxApp::OnAssertFailure() whose
319 default behaviour is, in turn, to show the standard assertion failure
320 dialog if a wxApp object exists or shows the same dialog itself directly
321 otherwise.
322
323 While usually it is enough -- and more convenient -- to just override
324 OnAssertFailure(), to handle all assertion failures, including those
325 occurring even before wxApp object creation of after its destruction you
326 need to provide your assertion handler function.
327
328 This function also provides a simple way to disable all asserts: simply
329 pass @NULL pointer to it. Doing this will result in not even evaluating
330 assert conditions at all, avoiding almost all run-time cost of asserts.
331
332 Notice that this function is not MT-safe, so you should call it before
333 starting any other threads.
334
335 The return value of this function is the previous assertion handler. It can
336 be called after any pre-processing by your handler and can also be restored
337 later if you uninstall your handler.
338
339 @param handler
340 The function to call in case of assertion failure or @NULL.
341 @return
342 The previous assert handler which is not @NULL by default but could be
343 @NULL if it had been previously set to this value using this function.
344
345 @since 2.9.0
346
347 @header{wx/debug.h}
348 */
349 wxAssertHandler_t wxSetAssertHandler(wxAssertHandler_t handler);
350
351 /**
352 Reset the assert handler to default function which shows a message box when
353 an assert happens.
354
355 This can be useful for the applications compiled in release build (with @c
356 NDEBUG defined) for which the asserts are by default disabled: if you wish
357 to enable them even in this case you need to call this function.
358
359 @since 2.9.1
360
361 @header{wx/debug.h}
362 */
363 void wxSetDefaultAssertHandler();
364
365 /**
366 Generate a debugger exception meaning that the control is passed to the
367 debugger if one is attached to the process.
368
369 Otherwise the program just terminates abnormally.
370
371 If @c wxDEBUG_LEVEL is 0 (which is not the default) this function does
372 nothing.
373
374 @header{wx/debug.h}
375 */
376 void wxTrap();
377
378 //@}
379