include/wx/debug.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/debug.h
   3 // Purpose:     Misc debug functions and macros
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     29/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef   _WX_DEBUG_H_
  13 #define   _WX_DEBUG_H_
  14
  15 #include  <assert.h>
  16
  17 #include  "wx/wxchar.h"
  18
  19 // ----------------------------------------------------------------------------
  20 /**
  21   @name Debugging macros
  22
  23   All debugging macros rely on ASSERT() which in turn calls user-defined
  24   OnAssert() function. To keep things simple, it's called even when the
  25   expression is TRUE (i.e. everything is ok) and by default does nothing: just
  26   returns the same value back. But if you redefine it to do something more sexy
  27   (popping up a message box in your favourite GUI, sending you e-mail or
  28   whatever) it will affect all ASSERTs, FAILs and CHECKs in your code.
  29   <BR>
  30   <BR>
  31   <b>Warning</b>: if you don't like advices on programming style, don't read
  32   further! ;-)
  33   <BR>
  34   <BR>
  35   Extensive use of these macros is recommended! Remember that ASSERTs are
  36   disabled in final (without __WXDEBUG__ defined) build, so they add strictly
  37   nothing to your program's code. On the other hand, CHECK macros do stay
  38   even in release builds, but in general are not much of a burden, while
  39   a judicious use of them might increase your program's stability.
  40
  41   @memo Debugging macros (replacement for standard assert()) and more.
  42   */
  43 // ----------------------------------------------------------------------------
  44 //@{
  45
  46 // Use of these suppresses compiler warnings about testing constant expression
  47 WXDLLEXPORT_DATA(extern const bool) wxTrue;
  48 WXDLLEXPORT_DATA(extern const bool) wxFalse;
  49
  50 /** @name Macros which are completely disabled in 'release' mode */
  51 //@{
  52 #ifdef  __WXDEBUG__
  53   /**
  54   this function may be redefined to do something non trivial and is called
  55   whenever one of debugging macros fails (i.e. condition is false in an
  56   assertion)
  57   @param   szFile and nLine - file name and line number of the ASSERT
  58            szMsg            - optional message explaining the reason
  59   */
  60   void WXDLLEXPORT wxOnAssert(const wxChar *szFile, int nLine, const wxChar *szMsg = (const wxChar *) NULL);
  61
  62   /// generic assert macro
  63   #define   wxASSERT(cond)   if ( !(cond) ) wxOnAssert(__TFILE__, __LINE__)
  64
  65   /// assert with additional message explaining it's cause
  66   #define   wxASSERT_MSG(x, m)  if ( !(x) ) wxOnAssert(__TFILE__, __LINE__, m)
  67 #else
  68   // nothing to do in release modes (hopefully at this moment there are
  69   // no more bugs ;-)
  70   #define   wxASSERT(cond)
  71   #define   wxASSERT_MSG(x, m)
  72 #endif  //__WXDEBUG__
  73
  74 /// special form of assert: always triggers it (in debug mode)
  75 #define   wxFAIL                 wxASSERT(wxFalse)
  76
  77 /// FAIL with some message
  78 #define   wxFAIL_MSG(msg)        wxASSERT_MSG(wxFalse, msg)
  79 //@}
  80
  81 // NB: these macros work also in release mode!
  82
  83 /**
  84   These macros must be used only in invalid situation: for example, an
  85   invalid parameter (NULL pointer) is passed to a function. Instead of
  86   dereferencing it and causing core dump the function might try using
  87   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
  88
  89   @name Macros which remain even in 'release' mode
  90 */
  91 //@{
  92   /// check that expression is true, "return" if not (also FAILs in debug mode)
  93 #define   wxCHECK(x, rc)            if (!(x)) {wxFAIL; return rc; }
  94   /// as wxCHECK but with a message explaining why we fail
  95 #define   wxCHECK_MSG(x, rc, msg)   if (!(x)) {wxFAIL_MSG(msg); return rc; }
  96   /// check that expression is true, perform op if not
  97 #define   wxCHECK2(x, op)           if (!(x)) {wxFAIL; op; }
  98   /// as wxCHECK2 but with a message explaining why we fail
  99 #define   wxCHECK2_MSG(x, op, msg)  if (!(x)) {wxFAIL_MSG(msg); op; }
 100   /// special form of wxCHECK2: as wxCHECK, but for use in void functions
 101   //  NB: there is only one form (with msg parameter) and it's intentional:
 102   //      there is no other way to tell the caller what exactly went wrong
 103   //      from the void function (of course, the function shouldn't be void
 104   //      to begin with...)
 105 #define   wxCHECK_RET(x, msg)       if (!(x)) {wxFAIL_MSG(msg); return; }
 106 //@}
 107
 108 //@}
 109
 110 #endif  // _WX_DEBUG_H_