include/wx/debug.h

   1 /**
   2 *  Name:        wx/debug.h
   3 *  Purpose:     Misc debug functions and macros
   4 *  Author:      Vadim Zeitlin
   5 *  Modified by: Ryan Norton (Converted to C)
   6 *  Created:     29/01/98
   7 *  RCS-ID:      $Id$
   8 *  Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 *  Licence:     wxWindows licence
  10 */
  11
  12 /* THIS IS A C FILE, DON'T USE C++ FEATURES (IN PARTICULAR COMMENTS) IN IT */
  13
  14 #ifndef   _WX_DEBUG_H_
  15 #define   _WX_DEBUG_H_
  16
  17 #ifndef __WXWINCE__
  18 #include  <assert.h>
  19 #endif
  20 #include  <limits.h>            /*  for CHAR_BIT used below */
  21
  22 #include  "wx/chartype.h"     /*  for __TFILE__ and wxChar */
  23
  24 /*  ---------------------------------------------------------------------------- */
  25 /*  Defines controlling the debugging macros */
  26 /*  ---------------------------------------------------------------------------- */
  27
  28 /*  if _DEBUG is defined (MS VC++ and others use it in debug builds), define */
  29 /*  __WXDEBUG__ too */
  30 #ifdef _DEBUG
  31     #ifndef __WXDEBUG__
  32         #define __WXDEBUG__
  33     #endif /*  !__WXDEBUG__ */
  34 #endif /*  _DEBUG */
  35
  36 /*  if NDEBUG is defined (<assert.h> uses it), undef __WXDEBUG__ and WXDEBUG */
  37 #ifdef NDEBUG
  38     #undef __WXDEBUG__
  39     #undef WXDEBUG
  40 #endif /*  NDEBUG */
  41
  42 /*  if __WXDEBUG__ is defined, make sure that WXDEBUG is defined and >= 1 */
  43 #ifdef __WXDEBUG__
  44     #if !defined(WXDEBUG) || !WXDEBUG
  45         #undef WXDEBUG
  46         #define WXDEBUG 1
  47     #endif /*  !WXDEBUG */
  48 #endif /*  __WXDEBUG__ */
  49
  50 #ifndef __WXFUNCTION__
  51     /* TODO: add more compilers supporting __FUNCTION__ */
  52     #if defined(__DMC__)
  53         /*
  54            __FUNCTION__ happens to be not defined within class members
  55            http://www.digitalmars.com/drn-bin/wwwnews?c%2B%2B.beta/485
  56         */
  57         #define __WXFUNCTION__ (NULL)
  58     #elif defined(__GNUC__) || \
  59           (defined(_MSC_VER) && _MSC_VER >= 1300) || \
  60           defined(__FUNCTION__)
  61         #define __WXFUNCTION__ __FUNCTION__
  62     #else
  63         /* still define __WXFUNCTION__ to avoid #ifdefs elsewhere */
  64         #define __WXFUNCTION__ (NULL)
  65     #endif
  66 #endif /* __WXFUNCTION__ already defined */
  67
  68 /*  ---------------------------------------------------------------------------- */
  69 /*  Debugging macros */
  70 /*  */
  71 /*  All debugging macros rely on ASSERT() which in turn calls the user-defined */
  72 /*  OnAssert() function. To keep things simple, it's called even when the */
  73 /*  expression is true (i.e. everything is ok) and by default does nothing: just */
  74 /*  returns the same value back. But if you redefine it to do something more sexy */
  75 /*  (popping up a message box in your favourite GUI, sending you e-mail or */
  76 /*  whatever) it will affect all ASSERTs, FAILs and CHECKs in your code. */
  77 /*  */
  78 /*  Warning: if you don't like advice on programming style, don't read */
  79 /*  further! ;-) */
  80 /*  */
  81 /*  Extensive use of these macros is recommended! Remember that ASSERTs are */
  82 /*  disabled in final build (without __WXDEBUG__ defined), so they add strictly */
  83 /*  nothing to your program's code. On the other hand, CHECK macros do stay */
  84 /*  even in release builds, but in general are not much of a burden, while */
  85 /*  a judicious use of them might increase your program's stability. */
  86 /*  ---------------------------------------------------------------------------- */
  87
  88 /*  Macros which are completely disabled in 'release' mode */
  89 /*  */
  90 /*  NB: these functions are implemented in src/common/appcmn.cpp */
  91 #if defined(__cplusplus) && defined(__WXDEBUG__)
  92   /*
  93     This function is called whenever one of debugging macros fails (i.e.
  94     condition is false in an assertion). To customize its behaviour, override
  95     wxApp::OnAssert().
  96
  97     Parameters:
  98        szFile and nLine - file name and line number of the ASSERT
  99        szFunc           - function name of the ASSERT, may be NULL (NB: ASCII)
 100        szCond           - text form of the condition which failed
 101        szMsg            - optional message explaining the reason
 102   */
 103
 104   /* this version is for compatibility with wx 2.8: */
 105   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
 106                                           int nLine,
 107                                           const char *szFunc,
 108                                           const wxChar *szCond,
 109                                           const wxChar *szMsg = NULL);
 110
 111 #if wxUSE_UNICODE
 112   /* char versions are used by debugging macros; we have to provide
 113      wxChar* szMsg version because it's common to use _T() in the macros
 114      and finally, we can't use const wx(char)* szMsg = NULL, because that
 115      would be ambiguous: */
 116   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 117                                           int nLine,
 118                                           const char *szFunc,
 119                                           const char *szCond);
 120
 121   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 122                                           int nLine,
 123                                           const char *szFunc,
 124                                           const char *szCond,
 125                                           const char *szMsg);
 126
 127   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 128                                           int nLine,
 129                                           const char *szFunc,
 130                                           const char *szCond,
 131                                           const wxChar *szMsg);
 132 #endif // wxUSE_UNICODE
 133
 134   class WXDLLIMPEXP_BASE wxString;
 135   /* these two work when szMsg passed to debug macro is a string: */
 136   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
 137                                           int nLine,
 138                                           const wxString& szFunc,
 139                                           const wxString& szCond,
 140                                           const wxString& szMsg);
 141
 142   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
 143                                           int nLine,
 144                                           const wxString& szFunc,
 145                                           const wxString& szCond);
 146
 147   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 148                                           int nLine,
 149                                           const char *szFunc,
 150                                           const char *szCond,
 151                                           const wxString& szMsg);
 152
 153   /*  call this function to break into the debugger unconditionally (assuming */
 154   /*  the program is running under debugger, of course) */
 155   extern void WXDLLIMPEXP_BASE wxTrap();
 156
 157   /*  generic assert macro */
 158   #define wxASSERT(cond) wxASSERT_MSG(cond, (const char*)NULL)
 159
 160
 161   /*  assert with additional message explaining its cause */
 162
 163   /*  compilers can give a warning (such as "possible unwanted ;") when using */
 164   /*  the default definition of wxASSERT_MSG so we provide an alternative */
 165   #if defined(__MWERKS__)
 166     #define wxASSERT_MSG(cond, msg)                                           \
 167       if ( cond )                                                             \
 168       {}                                                                      \
 169       else                                                                    \
 170           wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, #cond, msg)
 171   #else
 172     #define wxASSERT_MSG(cond, msg)                                           \
 173       if ( cond )                                                             \
 174           ;                                                                   \
 175       else                                                                    \
 176           wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, #cond, msg)
 177   #endif
 178
 179   /*  special form of assert: always triggers it (in debug mode) */
 180   #define wxFAIL wxFAIL_MSG((const char*)NULL)
 181
 182   /*  FAIL with some message */
 183   #define wxFAIL_MSG(msg) wxFAIL_COND_MSG("wxAssertFailure", msg)
 184
 185   /*  FAIL with some message and a condition */
 186   #define wxFAIL_COND_MSG(cond, msg)                                          \
 187       wxOnAssert(__FILE__, __LINE__,  __WXFUNCTION__, cond, msg)
 188
 189   /*  An assert helper used to avoid warning when testing constant expressions, */
 190   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 191   /*  expression being always true, but not using */
 192   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 193   /*  */
 194   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and should no */
 195   /*      longer be used. */
 196   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 197 #else
 198   #define wxTrap()
 199
 200   /*  nothing to do in release mode (hopefully at this moment there are */
 201   /*  no more bugs ;-) */
 202   #define wxASSERT(cond)
 203   #define wxASSERT_MSG(cond, msg)
 204   #define wxFAIL
 205   #define wxFAIL_MSG(msg)
 206   #define wxFAIL_COND_MSG(cond, msg)
 207 #endif  /* __WXDEBUG__ */
 208
 209 #ifdef __cplusplus
 210     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 211     /*  constant expression */
 212     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 213 #endif
 214
 215 #define wxAssertFailure wxFalse
 216
 217 /*  NB: the following macros also work in release mode! */
 218
 219 /*
 220   These macros must be used only in invalid situation: for example, an
 221   invalid parameter (e.g. a NULL pointer) is passed to a function. Instead of
 222   dereferencing it and causing core dump the function might try using
 223   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 224 */
 225
 226 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 227 #define wxCHECK(cond, rc)            wxCHECK_MSG(cond, rc, (const char*)NULL)
 228
 229 /*  as wxCHECK but with a message explaining why we fail */
 230 #define wxCHECK_MSG(cond, rc, msg)   wxCHECK2_MSG(cond, return rc, msg)
 231
 232 /*  check that expression is true, perform op if not */
 233 #define wxCHECK2(cond, op)           wxCHECK2_MSG(cond, op, (const char*)NULL)
 234
 235 /*  as wxCHECK2 but with a message explaining why we fail */
 236
 237 /* see comment near the definition of wxASSERT_MSG for the # if/else reason */
 238 #if defined(__MWERKS__)
 239     #define wxCHECK2_MSG(cond, op, msg)                                       \
 240         if ( cond )                                                           \
 241         {}                                                                    \
 242         else                                                                  \
 243         {                                                                     \
 244             wxFAIL_COND_MSG(#cond, msg);                                      \
 245             op;                                                               \
 246         }                                                                     \
 247         struct wxDummyCheckStruct /* just to force a semicolon */
 248 #else
 249     #define wxCHECK2_MSG(cond, op, msg)                                       \
 250         if ( cond )                                                           \
 251             ;                                                                 \
 252         else                                                                  \
 253         {                                                                     \
 254             wxFAIL_COND_MSG(#cond, msg);                                      \
 255             op;                                                               \
 256         }                                                                     \
 257         struct wxDummyCheckStruct /* just to force a semicolon */
 258 #endif
 259
 260 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 261 /*  */
 262 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 263 /*      there is no other way to tell the caller what exactly went wrong */
 264 /*      from the void function (of course, the function shouldn't be void */
 265 /*      to begin with...) */
 266 #define wxCHECK_RET(cond, msg)       wxCHECK2_MSG(cond, return, msg)
 267
 268 /*  ---------------------------------------------------------------------------- */
 269 /*  Compile time asserts */
 270 /*  */
 271 /*  Unlike the normal assert and related macros above which are checked during */
 272 /*  the program tun-time the macros below will result in a compilation error if */
 273 /*  the condition they check is false. This is usually used to check the */
 274 /*  expressions containing sizeof()s which cannot be tested with the */
 275 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 276 /*  detailed error message then. */
 277 /*  ---------------------------------------------------------------------------- */
 278
 279 /*
 280   How this works (you don't have to understand it to be able to use the
 281   macros): we rely on the fact that it is invalid to define a named bit field
 282   in a struct of width 0. All the rest are just the hacks to minimize the
 283   possibility of the compiler warnings when compiling this macro: in
 284   particular, this is why we define a struct and not an object (which would
 285   result in a warning about unused variable) and a named struct (otherwise we'd
 286   get a warning about an unnamed struct not used to define an object!).
 287  */
 288
 289 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 290
 291 /*
 292   The second argument of this macro must be a valid C++ identifier and not a
 293   string. I.e. you should use it like this:
 294
 295     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 296
 297  It may be used both within a function and in the global scope.
 298 */
 299 #if defined(__WATCOMC__) && defined(__cplusplus)
 300     /* avoid "unused symbol" warning */
 301     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 302         class wxMAKE_UNIQUE_ASSERT_NAME { \
 303           unsigned int msg: expr; \
 304           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 305         }
 306 #else
 307     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 308         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 309 #endif
 310
 311 /*
 312    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 313    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 314    way to make "unique" assert names by specifying a unique prefix explicitly
 315  */
 316 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 317
 318 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 319     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 320
 321 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 322 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 323
 324 /*  a special case of compile time assert: check that the size of the given type */
 325 /*  is at least the given number of bits */
 326 #define wxASSERT_MIN_BITSIZE(type, size) \
 327     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 328                           wxMAKE_BITSIZE_MSG(type, size))
 329
 330 /*  ---------------------------------------------------------------------------- */
 331 /*  other miscellaneous debugger-related functions */
 332 /*  ---------------------------------------------------------------------------- */
 333
 334 /*
 335     Return true if we're running under debugger.
 336
 337     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 338     it always returns false in other cases.
 339  */
 340 #ifdef __cplusplus
 341     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 342     #if defined(__WXMAC__) || defined(__WIN32__)
 343         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 344     #else /*  !Mac */
 345         inline bool wxIsDebuggerRunning() { return false; }
 346     #endif /*  Mac/!Mac */
 347 #endif /* __cplusplus */
 348
 349 #endif  /*  _WX_DEBUG_H_ */