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 __WXPALMOS5__
  18 #ifndef __WXWINCE__
  19 #include  <assert.h>
  20 #endif
  21 #endif // ! __WXPALMOS5__
  22 #include  <limits.h>            /*  for CHAR_BIT used below */
  23
  24 #include  "wx/chartype.h"     /*  for __TFILE__ and wxChar */
  25
  26 /*  ---------------------------------------------------------------------------- */
  27 /*  Defines controlling the debugging macros */
  28 /*  ---------------------------------------------------------------------------- */
  29
  30 /*  if _DEBUG is defined (MS VC++ and others use it in debug builds), define */
  31 /*  __WXDEBUG__ too */
  32 #ifdef _DEBUG
  33     #ifndef __WXDEBUG__
  34         #define __WXDEBUG__
  35     #endif /*  !__WXDEBUG__ */
  36 #endif /*  _DEBUG */
  37
  38 /*  if NDEBUG is defined (<assert.h> uses it), undef __WXDEBUG__ and WXDEBUG */
  39 #ifdef NDEBUG
  40     #undef __WXDEBUG__
  41     #undef WXDEBUG
  42 #endif /*  NDEBUG */
  43
  44 /*  if __WXDEBUG__ is defined, make sure that WXDEBUG is defined and >= 1 */
  45 #ifdef __WXDEBUG__
  46     #if !defined(WXDEBUG) || !WXDEBUG
  47         #undef WXDEBUG
  48         #define WXDEBUG 1
  49     #endif /*  !WXDEBUG */
  50 #endif /*  __WXDEBUG__ */
  51
  52 #ifndef __WXFUNCTION__
  53     /* TODO: add more compilers supporting __FUNCTION__ */
  54     #if defined(__DMC__)
  55         /*
  56            __FUNCTION__ happens to be not defined within class members
  57            http://www.digitalmars.com/drn-bin/wwwnews?c%2B%2B.beta/485
  58         */
  59         #define __WXFUNCTION__ (NULL)
  60     #elif defined(__GNUC__) || \
  61           (defined(_MSC_VER) && _MSC_VER >= 1300) || \
  62           defined(__FUNCTION__)
  63         #define __WXFUNCTION__ __FUNCTION__
  64     #else
  65         /* still define __WXFUNCTION__ to avoid #ifdefs elsewhere */
  66         #define __WXFUNCTION__ (NULL)
  67     #endif
  68 #endif /* __WXFUNCTION__ already defined */
  69
  70 /*  ---------------------------------------------------------------------------- */
  71 /*  Debugging macros */
  72 /*  */
  73 /*  All debugging macros rely on ASSERT() which in turn calls the user-defined */
  74 /*  OnAssert() function. To keep things simple, it's called even when the */
  75 /*  expression is true (i.e. everything is ok) and by default does nothing: just */
  76 /*  returns the same value back. But if you redefine it to do something more sexy */
  77 /*  (popping up a message box in your favourite GUI, sending you e-mail or */
  78 /*  whatever) it will affect all ASSERTs, FAILs and CHECKs in your code. */
  79 /*  */
  80 /*  Warning: if you don't like advice on programming style, don't read */
  81 /*  further! ;-) */
  82 /*  */
  83 /*  Extensive use of these macros is recommended! Remember that ASSERTs are */
  84 /*  disabled in final build (without __WXDEBUG__ defined), so they add strictly */
  85 /*  nothing to your program's code. On the other hand, CHECK macros do stay */
  86 /*  even in release builds, but in general are not much of a burden, while */
  87 /*  a judicious use of them might increase your program's stability. */
  88 /*  ---------------------------------------------------------------------------- */
  89
  90 /*  Macros which are completely disabled in 'release' mode */
  91 /*  */
  92 /*  NB: these functions are implemented in src/common/appcmn.cpp */
  93 #if defined(__cplusplus) && defined(__WXDEBUG__)
  94   /*
  95     This function is called whenever one of debugging macros fails (i.e.
  96     condition is false in an assertion). To customize its behaviour, override
  97     wxApp::OnAssertFailure().
  98
  99     Parameters:
 100        szFile and nLine - file name and line number of the ASSERT
 101        szFunc           - function name of the ASSERT, may be NULL (NB: ASCII)
 102        szCond           - text form of the condition which failed
 103        szMsg            - optional message explaining the reason
 104   */
 105
 106   /* this version is for compatibility with wx 2.8 Unicode build only: */
 107   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
 108                                           int nLine,
 109                                           const char *szFunc,
 110                                           const wxChar *szCond,
 111                                           const wxChar *szMsg = NULL);
 112
 113 #if wxUSE_UNICODE
 114   /* char versions are used by debugging macros; we have to provide
 115      wxChar* szMsg version because it's common to use _T() in the macros
 116      and finally, we can't use const wx(char)* szMsg = NULL, because that
 117      would be ambiguous: */
 118   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 119                                           int nLine,
 120                                           const char *szFunc,
 121                                           const char *szCond);
 122
 123   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 124                                           int nLine,
 125                                           const char *szFunc,
 126                                           const char *szCond,
 127                                           const char *szMsg);
 128
 129   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 130                                           int nLine,
 131                                           const char *szFunc,
 132                                           const char *szCond,
 133                                           const wxChar *szMsg);
 134 #endif /* wxUSE_UNICODE */
 135
 136   class WXDLLIMPEXP_FWD_BASE wxString;
 137   class WXDLLIMPEXP_FWD_BASE wxCStrData;
 138
 139   /* these two work when szMsg passed to debug macro is a string,
 140      we also have to provide wxCStrData overload to resolve ambiguity
 141      which would otherwise arise from wxASSERT( s.c_str() ): */
 142   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
 143                                           int nLine,
 144                                           const wxString& szFunc,
 145                                           const wxString& szCond,
 146                                           const wxString& szMsg);
 147
 148   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
 149                                           int nLine,
 150                                           const wxString& szFunc,
 151                                           const wxString& szCond);
 152
 153   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 154                                           int nLine,
 155                                           const char *szFunc,
 156                                           const char *szCond,
 157                                           const wxCStrData& msg);
 158
 159   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 160                                           int nLine,
 161                                           const char *szFunc,
 162                                           const char *szCond,
 163                                           const wxString& szMsg);
 164
 165   /*  call this function to break into the debugger unconditionally (assuming */
 166   /*  the program is running under debugger, of course) */
 167   extern void WXDLLIMPEXP_BASE wxTrap();
 168
 169   /*  generic assert macro */
 170   #define wxASSERT(cond) wxASSERT_MSG(cond, (const char*)NULL)
 171
 172
 173   /*  assert with additional message explaining its cause */
 174
 175   /*  Note: some compilers will give  a warning (such as           */
 176   /*  "possible unwanted ;") when using a ";" instead of the "{}". */
 177   #define wxASSERT_MSG(cond, msg)                                           \
 178     if ( cond )                                                             \
 179     {}                                                                      \
 180     else                                                                    \
 181         wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, #cond, msg)
 182
 183   /*  special form of assert: always triggers it (in debug mode) */
 184   #define wxFAIL wxFAIL_MSG((const char*)NULL)
 185
 186   /*  FAIL with some message */
 187   #define wxFAIL_MSG(msg) wxFAIL_COND_MSG("wxAssertFailure", msg)
 188
 189   /*  FAIL with some message and a condition */
 190   #define wxFAIL_COND_MSG(cond, msg)                                          \
 191       wxOnAssert(__FILE__, __LINE__,  __WXFUNCTION__, cond, msg)
 192
 193   /*  An assert helper used to avoid warning when testing constant expressions, */
 194   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 195   /*  expression being always true, but not using */
 196   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 197   /*  */
 198   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and should no */
 199   /*      longer be used. */
 200   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 201 #else
 202   #define wxTrap()
 203
 204   /*  nothing to do in release mode (hopefully at this moment there are */
 205   /*  no more bugs ;-) */
 206   #define wxASSERT(cond)
 207   #define wxASSERT_MSG(cond, msg)
 208   #define wxFAIL
 209   #define wxFAIL_MSG(msg)
 210   #define wxFAIL_COND_MSG(cond, msg)
 211 #endif  /* __WXDEBUG__ */
 212
 213 #ifdef __cplusplus
 214     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 215     /*  constant expression */
 216     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 217 #endif
 218
 219 #define wxAssertFailure wxFalse
 220
 221 /*  NB: the following macros also work in release mode! */
 222
 223 /*
 224   These macros must be used only in invalid situation: for example, an
 225   invalid parameter (e.g. a NULL pointer) is passed to a function. Instead of
 226   dereferencing it and causing core dump the function might try using
 227   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 228 */
 229
 230 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 231 #define wxCHECK(cond, rc)            wxCHECK_MSG(cond, rc, (const char*)NULL)
 232
 233 /*  as wxCHECK but with a message explaining why we fail */
 234 #define wxCHECK_MSG(cond, rc, msg)   wxCHECK2_MSG(cond, return rc, msg)
 235
 236 /*  check that expression is true, perform op if not */
 237 #define wxCHECK2(cond, op)           wxCHECK2_MSG(cond, op, (const char*)NULL)
 238
 239 /*  as wxCHECK2 but with a message explaining why we fail */
 240
 241 #define wxCHECK2_MSG(cond, op, msg)                                       \
 242     if ( cond )                                                           \
 243     {}                                                                    \
 244     else                                                                  \
 245     {                                                                     \
 246         wxFAIL_COND_MSG(#cond, msg);                                      \
 247         op;                                                               \
 248     }                                                                     \
 249     struct wxDummyCheckStruct /* just to force a semicolon */
 250
 251 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 252 /*  */
 253 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 254 /*      there is no other way to tell the caller what exactly went wrong */
 255 /*      from the void function (of course, the function shouldn't be void */
 256 /*      to begin with...) */
 257 #define wxCHECK_RET(cond, msg)       wxCHECK2_MSG(cond, return, msg)
 258
 259 /*  ---------------------------------------------------------------------------- */
 260 /*  Compile time asserts */
 261 /*  */
 262 /*  Unlike the normal assert and related macros above which are checked during */
 263 /*  the program tun-time the macros below will result in a compilation error if */
 264 /*  the condition they check is false. This is usually used to check the */
 265 /*  expressions containing sizeof()s which cannot be tested with the */
 266 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 267 /*  detailed error message then. */
 268 /*  ---------------------------------------------------------------------------- */
 269
 270 /*
 271   How this works (you don't have to understand it to be able to use the
 272   macros): we rely on the fact that it is invalid to define a named bit field
 273   in a struct of width 0. All the rest are just the hacks to minimize the
 274   possibility of the compiler warnings when compiling this macro: in
 275   particular, this is why we define a struct and not an object (which would
 276   result in a warning about unused variable) and a named struct (otherwise we'd
 277   get a warning about an unnamed struct not used to define an object!).
 278  */
 279
 280 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 281
 282 /*
 283   The second argument of this macro must be a valid C++ identifier and not a
 284   string. I.e. you should use it like this:
 285
 286     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 287
 288  It may be used both within a function and in the global scope.
 289 */
 290 #if defined(__WATCOMC__) && defined(__cplusplus)
 291     /* avoid "unused symbol" warning */
 292     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 293         class wxMAKE_UNIQUE_ASSERT_NAME { \
 294           unsigned int msg: expr; \
 295           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 296         }
 297 #else
 298     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 299         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 300 #endif
 301
 302 /*
 303    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 304    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 305    way to make "unique" assert names by specifying a unique prefix explicitly
 306  */
 307 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 308
 309 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 310     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 311
 312 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 313 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 314
 315 /*  a special case of compile time assert: check that the size of the given type */
 316 /*  is at least the given number of bits */
 317 #define wxASSERT_MIN_BITSIZE(type, size) \
 318     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 319                           wxMAKE_BITSIZE_MSG(type, size))
 320
 321 /*  ---------------------------------------------------------------------------- */
 322 /*  other miscellaneous debugger-related functions */
 323 /*  ---------------------------------------------------------------------------- */
 324
 325 /*
 326     Return true if we're running under debugger.
 327
 328     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 329     it always returns false in other cases.
 330  */
 331 #ifdef __cplusplus
 332     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 333     #if defined(__WXMAC__) || defined(__WIN32__)
 334         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 335     #else /*  !Mac */
 336         inline bool wxIsDebuggerRunning() { return false; }
 337     #endif /*  Mac/!Mac */
 338 #endif /* __cplusplus */
 339
 340 #endif  /*  _WX_DEBUG_H_ */