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/wxchar.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 /* TODO: add more compilers supporting __FUNCTION__ */
  51 #if defined(__GNUC__) || (defined(_MSC_VER) && _MSC_VER >= 1300)
  52     #define __TFUNC__ wxAPPLY_T(__FUNCTION__)
  53 #else /* old compilers without __FUNCTION__ support */
  54     #define __TFUNC__ _T("")
  55 #endif
  56
  57 /*  ---------------------------------------------------------------------------- */
  58 /*  Debugging macros */
  59 /*  */
  60 /*  All debugging macros rely on ASSERT() which in turn calls user-defined */
  61 /*  OnAssert() function. To keep things simple, it's called even when the */
  62 /*  expression is true (i.e. everything is ok) and by default does nothing: just */
  63 /*  returns the same value back. But if you redefine it to do something more sexy */
  64 /*  (popping up a message box in your favourite GUI, sending you e-mail or */
  65 /*  whatever) it will affect all ASSERTs, FAILs and CHECKs in your code. */
  66 /*  */
  67 /*  Warning: if you don't like advice on programming style, don't read */
  68 /*  further! ;-) */
  69 /*  */
  70 /*  Extensive use of these macros is recommended! Remember that ASSERTs are */
  71 /*  disabled in final build (without __WXDEBUG__ defined), so they add strictly */
  72 /*  nothing to your program's code. On the other hand, CHECK macros do stay */
  73 /*  even in release builds, but in general are not much of a burden, while */
  74 /*  a judicious use of them might increase your program's stability. */
  75 /*  ---------------------------------------------------------------------------- */
  76
  77 /*  Macros which are completely disabled in 'release' mode */
  78 /*  */
  79 /*  NB: these functions are implemented in src/common/appcmn.cpp */
  80 #if defined(__cplusplus) && defined(__WXDEBUG__)
  81   /*
  82     This function is called whenever one of debugging macros fails (i.e.
  83     condition is false in an assertion). To customize its behaviour, override
  84     wxApp::OnAssert().
  85
  86     Parameters:
  87        szFile and nLine - file name and line number of the ASSERT
  88        szFunc           - function name of the ASSERT, may be empty
  89        szCond           - text form of the condition which failed
  90        szMsg            - optional message explaining the reason
  91   */
  92   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
  93                                           int nLine,
  94                                           const wxChar *szFunc,
  95                                           const wxChar *szCond,
  96                                           const wxChar *szMsg = NULL);
  97
  98   /*  call this function to break into the debugger unconditionally (assuming */
  99   /*  the program is running under debugger, of course) */
 100   extern void WXDLLIMPEXP_BASE wxTrap();
 101
 102   /*  generic assert macro */
 103   #define wxASSERT(cond) wxASSERT_MSG(cond, NULL)
 104
 105   /*  assert with additional message explaining it's cause */
 106   #define wxASSERT_MSG(cond, msg)                                             \
 107     if ( cond )                                                               \
 108         ;                                                                     \
 109     else                                                                      \
 110         wxOnAssert(__TFILE__, __LINE__, __TFUNC__, _T(#cond), msg)
 111
 112   /*  special form of assert: always triggers it (in debug mode) */
 113   #define wxFAIL wxFAIL_MSG(NULL)
 114
 115   /*  FAIL with some message */
 116   #define wxFAIL_MSG(msg)                                                     \
 117       wxOnAssert(__TFILE__, __LINE__,  __TFUNC__, _T("wxAssertFailure"), msg)
 118
 119   /*  an assert helper used to avoid warning when testing constant expressions, */
 120   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 121   /*  expression being always true, but not using */
 122   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 123   /*  */
 124   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and shouldn't be */
 125   /*      used any longer */
 126   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 127 #else
 128   #define wxTrap()
 129
 130   /*  nothing to do in release modes (hopefully at this moment there are */
 131   /*  no more bugs ;-) */
 132   #define wxASSERT(cond)
 133   #define wxASSERT_MSG(cond, msg)
 134   #define wxFAIL
 135   #define wxFAIL_MSG(msg)
 136 #endif  /* __WXDEBUG__ */
 137
 138 #ifdef __cplusplus
 139     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 140     /*  constant expression */
 141     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 142 #endif
 143
 144 #define wxAssertFailure wxFalse
 145
 146 /*  NB: the following macros work also in release mode! */
 147
 148 /*
 149   These macros must be used only in invalid situation: for example, an
 150   invalid parameter (NULL pointer) is passed to a function. Instead of
 151   dereferencing it and causing core dump the function might try using
 152   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 153 */
 154
 155 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 156 #define wxCHECK(cond, rc)            wxCHECK_MSG(cond, rc, NULL)
 157
 158 /*  as wxCHECK but with a message explaining why we fail */
 159 #define wxCHECK_MSG(cond, rc, msg)   wxCHECK2_MSG(cond, return rc, msg)
 160
 161 /*  check that expression is true, perform op if not */
 162 #define wxCHECK2(cond, op)           wxCHECK2_MSG(cond, op, NULL)
 163
 164 /*  as wxCHECK2 but with a message explaining why we fail */
 165 #define wxCHECK2_MSG(cond, op, msg)                                           \
 166     if ( cond )                                                               \
 167         ;                                                                     \
 168     else                                                                      \
 169         do                                                                    \
 170         {                                                                     \
 171             wxOnAssert(__TFILE__, __LINE__, __TFUNC__, _T(#cond), msg);       \
 172             op;                                                               \
 173         } while ( 0 )
 174
 175 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 176 /*  */
 177 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 178 /*      there is no other way to tell the caller what exactly went wrong */
 179 /*      from the void function (of course, the function shouldn't be void */
 180 /*      to begin with...) */
 181 #define wxCHECK_RET(cond, msg)       wxCHECK2_MSG(cond, return, msg)
 182
 183 /*  ---------------------------------------------------------------------------- */
 184 /*  Compile time asserts */
 185 /*  */
 186 /*  Unlike the normal assert and related macros above which are checked during */
 187 /*  the program tun-time the macros below will result in a compilation error if */
 188 /*  the condition they check is false. This is usually used to check the */
 189 /*  expressions containing sizeof()s which cannot be tested with the */
 190 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 191 /*  detailed error message then. */
 192 /*  ---------------------------------------------------------------------------- */
 193
 194 /*
 195   How this works (you don't have to understand it to be able to use the
 196   macros): we rely on the fact that it is invalid to define a named bit field
 197   in a struct of width 0. All the rest are just the hacks to minimize the
 198   possibility of the compiler warnings when compiling this macro: in
 199   particular, this is why we define a struct and not an object (which would
 200   result in a warning about unused variable) and a named struct (otherwise we'd
 201   get a warning about an unnamed struct not used to define an object!).
 202  */
 203
 204 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 205
 206 /*
 207   The second argument of this macro must be a valid C++ identifier and not a
 208   string. I.e. you should use it like this:
 209
 210     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 211
 212  It may be used both within a function and in the global scope.
 213 */
 214 #if defined(__WATCOMC__) && defined(__cplusplus)
 215     /* avoid "unused symbol" warning */
 216     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 217         class wxMAKE_UNIQUE_ASSERT_NAME { \
 218           unsigned int msg: expr; \
 219           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 220         }
 221 #else
 222     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 223         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 224 #endif
 225
 226 /*
 227    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 228    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 229    way to make "unique" assert names by specifying a unique prefix explicitly
 230  */
 231 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 232
 233 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 234     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 235
 236 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 237 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 238
 239 /*  a special case of compile time assert: check that the size of the given type */
 240 /*  is at least the given number of bits */
 241 #define wxASSERT_MIN_BITSIZE(type, size) \
 242     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 243                           wxMAKE_BITSIZE_MSG(type, size))
 244
 245 /*  ---------------------------------------------------------------------------- */
 246 /*  other miscellaneous debugger-related functions */
 247 /*  ---------------------------------------------------------------------------- */
 248
 249 /*
 250     Return true if we're running under debugger.
 251
 252     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 253     it always returns false in other cases.
 254  */
 255 #ifdef __cplusplus
 256     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 257     #if defined(__WXMAC__) || defined(__WIN32__)
 258         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 259     #else /*  !Mac */
 260         inline bool wxIsDebuggerRunning() { return false; }
 261     #endif /*  Mac/!Mac */
 262 #endif /* __cplusplus */
 263
 264 #endif  /*  _WX_DEBUG_H_ */