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