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