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::OnAssertFailure().
  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 Unicode build only: */
 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   class WXDLLIMPEXP_BASE wxCStrData;
 136
 137   /* these two work when szMsg passed to debug macro is a string,
 138      we also have to provide wxCStrData overload to resolve ambiguity
 139      which would otherwise arise from wxASSERT( s.c_str() ): */
 140   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
 141                                           int nLine,
 142                                           const wxString& szFunc,
 143                                           const wxString& szCond,
 144                                           const wxString& szMsg);
 145
 146   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
 147                                           int nLine,
 148                                           const wxString& szFunc,
 149                                           const wxString& szCond);
 150
 151   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 152                                           int nLine,
 153                                           const char *szFunc,
 154                                           const char *szCond,
 155                                           const wxCStrData& msg);
 156
 157   extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
 158                                           int nLine,
 159                                           const char *szFunc,
 160                                           const char *szCond,
 161                                           const wxString& szMsg);
 162
 163   /*  call this function to break into the debugger unconditionally (assuming */
 164   /*  the program is running under debugger, of course) */
 165   extern void WXDLLIMPEXP_BASE wxTrap();
 166
 167   /*  generic assert macro */
 168   #define wxASSERT(cond) wxASSERT_MSG(cond, (const char*)NULL)
 169
 170
 171   /*  assert with additional message explaining its cause */
 172
 173   /*  compilers can give a warning (such as "possible unwanted ;") when using */
 174   /*  the default definition of wxASSERT_MSG so we provide an alternative */
 175   #if defined(__MWERKS__)
 176     #define wxASSERT_MSG(cond, msg)                                           \
 177       if ( cond )                                                             \
 178       {}                                                                      \
 179       else                                                                    \
 180           wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, #cond, msg)
 181   #else
 182     #define wxASSERT_MSG(cond, msg)                                           \
 183       if ( cond )                                                             \
 184           ;                                                                   \
 185       else                                                                    \
 186           wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, #cond, msg)
 187   #endif
 188
 189   /*  special form of assert: always triggers it (in debug mode) */
 190   #define wxFAIL wxFAIL_MSG((const char*)NULL)
 191
 192   /*  FAIL with some message */
 193   #define wxFAIL_MSG(msg) wxFAIL_COND_MSG("wxAssertFailure", msg)
 194
 195   /*  FAIL with some message and a condition */
 196   #define wxFAIL_COND_MSG(cond, msg)                                          \
 197       wxOnAssert(__FILE__, __LINE__,  __WXFUNCTION__, cond, msg)
 198
 199   /*  An assert helper used to avoid warning when testing constant expressions, */
 200   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 201   /*  expression being always true, but not using */
 202   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 203   /*  */
 204   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and should no */
 205   /*      longer be used. */
 206   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 207 #else
 208   #define wxTrap()
 209
 210   /*  nothing to do in release mode (hopefully at this moment there are */
 211   /*  no more bugs ;-) */
 212   #define wxASSERT(cond)
 213   #define wxASSERT_MSG(cond, msg)
 214   #define wxFAIL
 215   #define wxFAIL_MSG(msg)
 216   #define wxFAIL_COND_MSG(cond, msg)
 217 #endif  /* __WXDEBUG__ */
 218
 219 #ifdef __cplusplus
 220     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 221     /*  constant expression */
 222     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 223 #endif
 224
 225 #define wxAssertFailure wxFalse
 226
 227 /*  NB: the following macros also work in release mode! */
 228
 229 /*
 230   These macros must be used only in invalid situation: for example, an
 231   invalid parameter (e.g. a NULL pointer) is passed to a function. Instead of
 232   dereferencing it and causing core dump the function might try using
 233   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 234 */
 235
 236 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 237 #define wxCHECK(cond, rc)            wxCHECK_MSG(cond, rc, (const char*)NULL)
 238
 239 /*  as wxCHECK but with a message explaining why we fail */
 240 #define wxCHECK_MSG(cond, rc, msg)   wxCHECK2_MSG(cond, return rc, msg)
 241
 242 /*  check that expression is true, perform op if not */
 243 #define wxCHECK2(cond, op)           wxCHECK2_MSG(cond, op, (const char*)NULL)
 244
 245 /*  as wxCHECK2 but with a message explaining why we fail */
 246
 247 /* see comment near the definition of wxASSERT_MSG for the # if/else reason */
 248 #if defined(__MWERKS__)
 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 #else
 259     #define wxCHECK2_MSG(cond, op, msg)                                       \
 260         if ( cond )                                                           \
 261             ;                                                                 \
 262         else                                                                  \
 263         {                                                                     \
 264             wxFAIL_COND_MSG(#cond, msg);                                      \
 265             op;                                                               \
 266         }                                                                     \
 267         struct wxDummyCheckStruct /* just to force a semicolon */
 268 #endif
 269
 270 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 271 /*  */
 272 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 273 /*      there is no other way to tell the caller what exactly went wrong */
 274 /*      from the void function (of course, the function shouldn't be void */
 275 /*      to begin with...) */
 276 #define wxCHECK_RET(cond, msg)       wxCHECK2_MSG(cond, return, msg)
 277
 278 /*  ---------------------------------------------------------------------------- */
 279 /*  Compile time asserts */
 280 /*  */
 281 /*  Unlike the normal assert and related macros above which are checked during */
 282 /*  the program tun-time the macros below will result in a compilation error if */
 283 /*  the condition they check is false. This is usually used to check the */
 284 /*  expressions containing sizeof()s which cannot be tested with the */
 285 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 286 /*  detailed error message then. */
 287 /*  ---------------------------------------------------------------------------- */
 288
 289 /*
 290   How this works (you don't have to understand it to be able to use the
 291   macros): we rely on the fact that it is invalid to define a named bit field
 292   in a struct of width 0. All the rest are just the hacks to minimize the
 293   possibility of the compiler warnings when compiling this macro: in
 294   particular, this is why we define a struct and not an object (which would
 295   result in a warning about unused variable) and a named struct (otherwise we'd
 296   get a warning about an unnamed struct not used to define an object!).
 297  */
 298
 299 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 300
 301 /*
 302   The second argument of this macro must be a valid C++ identifier and not a
 303   string. I.e. you should use it like this:
 304
 305     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 306
 307  It may be used both within a function and in the global scope.
 308 */
 309 #if defined(__WATCOMC__) && defined(__cplusplus)
 310     /* avoid "unused symbol" warning */
 311     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 312         class wxMAKE_UNIQUE_ASSERT_NAME { \
 313           unsigned int msg: expr; \
 314           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 315         }
 316 #else
 317     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 318         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 319 #endif
 320
 321 /*
 322    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 323    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 324    way to make "unique" assert names by specifying a unique prefix explicitly
 325  */
 326 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 327
 328 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 329     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 330
 331 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 332 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 333
 334 /*  a special case of compile time assert: check that the size of the given type */
 335 /*  is at least the given number of bits */
 336 #define wxASSERT_MIN_BITSIZE(type, size) \
 337     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 338                           wxMAKE_BITSIZE_MSG(type, size))
 339
 340 /*  ---------------------------------------------------------------------------- */
 341 /*  other miscellaneous debugger-related functions */
 342 /*  ---------------------------------------------------------------------------- */
 343
 344 /*
 345     Return true if we're running under debugger.
 346
 347     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 348     it always returns false in other cases.
 349  */
 350 #ifdef __cplusplus
 351     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 352     #if defined(__WXMAC__) || defined(__WIN32__)
 353         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 354     #else /*  !Mac */
 355         inline bool wxIsDebuggerRunning() { return false; }
 356     #endif /*  Mac/!Mac */
 357 #endif /* __cplusplus */
 358
 359 #endif  /*  _WX_DEBUG_H_ */