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::OnAssert().
  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   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
 104                                           int nLine,
 105                                           const char *szFunc,
 106                                           const wxChar *szCond,
 107                                           const wxChar *szMsg = NULL);
 108
 109   /*  call this function to break into the debugger unconditionally (assuming */
 110   /*  the program is running under debugger, of course) */
 111   extern void WXDLLIMPEXP_BASE wxTrap();
 112
 113   /*  generic assert macro */
 114   #define wxASSERT(cond) wxASSERT_MSG(cond, NULL)
 115
 116
 117   /*  assert with additional message explaining its cause */
 118
 119   /*  compilers can give a warning (such as "possible unwanted ;") when using */
 120   /*  the default definition of wxASSERT_MSG so we provide an alternative */
 121   #if defined(__MWERKS__)
 122     #define wxASSERT_MSG(cond, msg)                                           \
 123       if ( cond )                                                             \
 124       {}                                                                      \
 125       else                                                                    \
 126           wxOnAssert(__TFILE__, __LINE__, __WXFUNCTION__, _T(#cond), msg)
 127   #else
 128     #define wxASSERT_MSG(cond, msg)                                           \
 129       if ( cond )                                                             \
 130           ;                                                                   \
 131       else                                                                    \
 132           wxOnAssert(__TFILE__, __LINE__, __WXFUNCTION__, _T(#cond), msg)
 133   #endif
 134
 135   /*  special form of assert: always triggers it (in debug mode) */
 136   #define wxFAIL wxFAIL_MSG(NULL)
 137
 138   /*  FAIL with some message */
 139   #define wxFAIL_MSG(msg) wxFAIL_COND_MSG("wxAssertFailure", msg)
 140
 141   /*  FAIL with some message and a condition */
 142   #define wxFAIL_COND_MSG(cond, msg)                                          \
 143       wxOnAssert(__TFILE__, __LINE__,  __WXFUNCTION__, _T(cond), msg)
 144
 145   /*  An assert helper used to avoid warning when testing constant expressions, */
 146   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 147   /*  expression being always true, but not using */
 148   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 149   /*  */
 150   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and should no */
 151   /*      longer be used. */
 152   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 153 #else
 154   #define wxTrap()
 155
 156   /*  nothing to do in release mode (hopefully at this moment there are */
 157   /*  no more bugs ;-) */
 158   #define wxASSERT(cond)
 159   #define wxASSERT_MSG(cond, msg)
 160   #define wxFAIL
 161   #define wxFAIL_MSG(msg)
 162   #define wxFAIL_COND_MSG(cond, msg)
 163 #endif  /* __WXDEBUG__ */
 164
 165 #ifdef __cplusplus
 166     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 167     /*  constant expression */
 168     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 169 #endif
 170
 171 #define wxAssertFailure wxFalse
 172
 173 /*  NB: the following macros also work in release mode! */
 174
 175 /*
 176   These macros must be used only in invalid situation: for example, an
 177   invalid parameter (e.g. a NULL pointer) is passed to a function. Instead of
 178   dereferencing it and causing core dump the function might try using
 179   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 180 */
 181
 182 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 183 #define wxCHECK(cond, rc)            wxCHECK_MSG(cond, rc, NULL)
 184
 185 /*  as wxCHECK but with a message explaining why we fail */
 186 #define wxCHECK_MSG(cond, rc, msg)   wxCHECK2_MSG(cond, return rc, msg)
 187
 188 /*  check that expression is true, perform op if not */
 189 #define wxCHECK2(cond, op)           wxCHECK2_MSG(cond, op, NULL)
 190
 191 /*  as wxCHECK2 but with a message explaining why we fail */
 192
 193 /* see comment near the definition of wxASSERT_MSG for the # if/else reason */
 194 #if defined(__MWERKS__)
 195     #define wxCHECK2_MSG(cond, op, msg)                                       \
 196         if ( cond )                                                           \
 197         {}                                                                    \
 198         else                                                                  \
 199         {                                                                     \
 200             wxFAIL_COND_MSG(#cond, msg);                                      \
 201             op;                                                               \
 202         }                                                                     \
 203         struct wxDummyCheckStruct /* just to force a semicolon */
 204 #else
 205     #define wxCHECK2_MSG(cond, op, msg)                                       \
 206         if ( cond )                                                           \
 207             ;                                                                 \
 208         else                                                                  \
 209         {                                                                     \
 210             wxFAIL_COND_MSG(#cond, msg);                                      \
 211             op;                                                               \
 212         }                                                                     \
 213         struct wxDummyCheckStruct /* just to force a semicolon */
 214 #endif
 215
 216 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 217 /*  */
 218 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 219 /*      there is no other way to tell the caller what exactly went wrong */
 220 /*      from the void function (of course, the function shouldn't be void */
 221 /*      to begin with...) */
 222 #define wxCHECK_RET(cond, msg)       wxCHECK2_MSG(cond, return, msg)
 223
 224 /*  ---------------------------------------------------------------------------- */
 225 /*  Compile time asserts */
 226 /*  */
 227 /*  Unlike the normal assert and related macros above which are checked during */
 228 /*  the program tun-time the macros below will result in a compilation error if */
 229 /*  the condition they check is false. This is usually used to check the */
 230 /*  expressions containing sizeof()s which cannot be tested with the */
 231 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 232 /*  detailed error message then. */
 233 /*  ---------------------------------------------------------------------------- */
 234
 235 /*
 236   How this works (you don't have to understand it to be able to use the
 237   macros): we rely on the fact that it is invalid to define a named bit field
 238   in a struct of width 0. All the rest are just the hacks to minimize the
 239   possibility of the compiler warnings when compiling this macro: in
 240   particular, this is why we define a struct and not an object (which would
 241   result in a warning about unused variable) and a named struct (otherwise we'd
 242   get a warning about an unnamed struct not used to define an object!).
 243  */
 244
 245 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 246
 247 /*
 248   The second argument of this macro must be a valid C++ identifier and not a
 249   string. I.e. you should use it like this:
 250
 251     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 252
 253  It may be used both within a function and in the global scope.
 254 */
 255 #if defined(__WATCOMC__) && defined(__cplusplus)
 256     /* avoid "unused symbol" warning */
 257     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 258         class wxMAKE_UNIQUE_ASSERT_NAME { \
 259           unsigned int msg: expr; \
 260           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 261         }
 262 #else
 263     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 264         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 265 #endif
 266
 267 /*
 268    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 269    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 270    way to make "unique" assert names by specifying a unique prefix explicitly
 271  */
 272 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 273
 274 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 275     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 276
 277 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 278 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 279
 280 /*  a special case of compile time assert: check that the size of the given type */
 281 /*  is at least the given number of bits */
 282 #define wxASSERT_MIN_BITSIZE(type, size) \
 283     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 284                           wxMAKE_BITSIZE_MSG(type, size))
 285
 286 /*  ---------------------------------------------------------------------------- */
 287 /*  other miscellaneous debugger-related functions */
 288 /*  ---------------------------------------------------------------------------- */
 289
 290 /*
 291     Return true if we're running under debugger.
 292
 293     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 294     it always returns false in other cases.
 295  */
 296 #ifdef __cplusplus
 297     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 298     #if defined(__WXMAC__) || defined(__WIN32__)
 299         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 300     #else /*  !Mac */
 301         inline bool wxIsDebuggerRunning() { return false; }
 302     #endif /*  Mac/!Mac */
 303 #endif /* __cplusplus */
 304
 305 #endif  /*  _WX_DEBUG_H_ */