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 /*  ---------------------------------------------------------------------------- */
  51 /*  Debugging macros */
  52 /*  */
  53 /*  All debugging macros rely on ASSERT() which in turn calls user-defined */
  54 /*  OnAssert() function. To keep things simple, it's called even when the */
  55 /*  expression is true (i.e. everything is ok) and by default does nothing: just */
  56 /*  returns the same value back. But if you redefine it to do something more sexy */
  57 /*  (popping up a message box in your favourite GUI, sending you e-mail or */
  58 /*  whatever) it will affect all ASSERTs, FAILs and CHECKs in your code. */
  59 /*  */
  60 /*  Warning: if you don't like advice on programming style, don't read */
  61 /*  further! ;-) */
  62 /*  */
  63 /*  Extensive use of these macros is recommended! Remember that ASSERTs are */
  64 /*  disabled in final build (without __WXDEBUG__ defined), so they add strictly */
  65 /*  nothing to your program's code. On the other hand, CHECK macros do stay */
  66 /*  even in release builds, but in general are not much of a burden, while */
  67 /*  a judicious use of them might increase your program's stability. */
  68 /*  ---------------------------------------------------------------------------- */
  69
  70 /*  Macros which are completely disabled in 'release' mode */
  71 /*  */
  72 /*  NB: these functions are implemented in src/common/appcmn.cpp */
  73 #if defined(__cplusplus) && defined(__WXDEBUG__)
  74   /*
  75     This function is called whenever one of debugging macros fails (i.e.
  76     condition is false in an assertion). To customize its behaviour, override
  77     wxApp::OnAssert().
  78
  79     Parameters:
  80        szFile and nLine - file name and line number of the ASSERT
  81        szCond           - text form of the condition which failed
  82        szMsg            - optional message explaining the reason
  83   */
  84   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
  85                                           int nLine,
  86                                           const wxChar *szCond,
  87                                           const wxChar *szMsg = NULL);
  88
  89   /*  call this function to break into the debugger unconditionally (assuming */
  90   /*  the program is running under debugger, of course) */
  91   extern void WXDLLIMPEXP_BASE wxTrap();
  92
  93   /*  generic assert macro */
  94   #define wxASSERT(cond) wxASSERT_MSG(cond, NULL)
  95
  96   /*  assert with additional message explaining it's cause */
  97   #define wxASSERT_MSG(cond, msg) \
  98     if (cond) ; else wxOnAssert(__TFILE__, __LINE__, _T(#cond), msg)
  99
 100   /*  special form of assert: always triggers it (in debug mode) */
 101   #define wxFAIL wxFAIL_MSG(NULL)
 102
 103   /*  FAIL with some message */
 104   #define wxFAIL_MSG(msg) wxOnAssert(__TFILE__, __LINE__, wxT("wxAssertFailure"), msg)
 105
 106   /*  an assert helper used to avoid warning when testing constant expressions, */
 107   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 108   /*  expression being always true, but not using */
 109   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 110   /*  */
 111   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and shouldn't be */
 112   /*      used any longer */
 113   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 114 #else
 115   #define wxTrap()
 116
 117   /*  nothing to do in release modes (hopefully at this moment there are */
 118   /*  no more bugs ;-) */
 119   #define wxASSERT(cond)
 120   #define wxASSERT_MSG(x, m)
 121   #define wxFAIL
 122   #define wxFAIL_MSG(msg)
 123 #endif  /* __WXDEBUG__ */
 124
 125 #ifdef __cplusplus
 126     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 127     /*  constant expression */
 128     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 129 #endif
 130
 131 #define wxAssertFailure wxFalse
 132
 133 /*  NB: the following macros work also in release mode! */
 134
 135 /*
 136   These macros must be used only in invalid situation: for example, an
 137   invalid parameter (NULL pointer) is passed to a function. Instead of
 138   dereferencing it and causing core dump the function might try using
 139   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 140 */
 141
 142 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 143 #define wxCHECK(x, rc)            wxCHECK_MSG(x, rc, NULL)
 144
 145 /*  as wxCHECK but with a message explaining why we fail */
 146 #define wxCHECK_MSG(x, rc, msg)   wxCHECK2_MSG(x, return rc, msg)
 147
 148 /*  check that expression is true, perform op if not */
 149 #define wxCHECK2(x, op)           wxCHECK2_MSG(x, op, NULL)
 150
 151 /*  as wxCHECK2 but with a message explaining why we fail */
 152 #define wxCHECK2_MSG(x, op, msg)  if (x) ; else do { wxFAIL_MSG(msg); op; } while (0)
 153
 154 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 155 /*  */
 156 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 157 /*      there is no other way to tell the caller what exactly went wrong */
 158 /*      from the void function (of course, the function shouldn't be void */
 159 /*      to begin with...) */
 160 #define wxCHECK_RET(x, msg)       wxCHECK2_MSG(x, return, msg)
 161
 162 /*  ---------------------------------------------------------------------------- */
 163 /*  Compile time asserts */
 164 /*  */
 165 /*  Unlike the normal assert and related macros above which are checked during */
 166 /*  the program tun-time the macros below will result in a compilation error if */
 167 /*  the condition they check is false. This is usually used to check the */
 168 /*  expressions containing sizeof()s which cannot be tested with the */
 169 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 170 /*  detailed error message then. */
 171 /*  ---------------------------------------------------------------------------- */
 172
 173 /*
 174   How this works (you don't have to understand it to be able to use the
 175   macros): we rely on the fact that it is invalid to define a named bit field
 176   in a struct of width 0. All the rest are just the hacks to minimize the
 177   possibility of the compiler warnings when compiling this macro: in
 178   particular, this is why we define a struct and not an object (which would
 179   result in a warning about unused variable) and a named struct (otherwise we'd
 180   get a warning about an unnamed struct not used to define an object!).
 181  */
 182
 183 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 184
 185 /*
 186   The second argument of this macro must be a valid C++ identifier and not a
 187   string. I.e. you should use it like this:
 188
 189     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 190
 191  It may be used both within a function and in the global scope.
 192 */
 193 #if defined(__WATCOMC__) && defined(__cplusplus)
 194     /* avoid "unused symbol" warning */
 195     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 196         class wxMAKE_UNIQUE_ASSERT_NAME { \
 197           unsigned int msg: expr; \
 198           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 199         }
 200 #else
 201     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 202         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 203 #endif
 204
 205 /*
 206    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 207    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 208    way to make "unique" assert names by specifying a unique prefix explicitly
 209  */
 210 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 211
 212 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 213     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 214
 215 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 216 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 217
 218 /*  a special case of compile time assert: check that the size of the given type */
 219 /*  is at least the given number of bits */
 220 #define wxASSERT_MIN_BITSIZE(type, size) \
 221     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 222                           wxMAKE_BITSIZE_MSG(type, size))
 223
 224 /*  ---------------------------------------------------------------------------- */
 225 /*  other miscellaneous debugger-related functions */
 226 /*  ---------------------------------------------------------------------------- */
 227
 228 /*
 229     Return true if we're running under debugger.
 230
 231     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 232     it always returns false in other cases.
 233  */
 234 #ifdef __cplusplus
 235     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 236     #if defined(__WXMAC__) || defined(__WIN32__)
 237         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 238     #else /*  !Mac */
 239         inline bool wxIsDebuggerRunning() { return false; }
 240     #endif /*  Mac/!Mac */
 241 #endif /* __cplusplus */
 242
 243 #endif  /*  _WX_DEBUG_H_ */