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 /* TODO: add more compilers supporting __FUNCTION__ */
  51 #if !defined(__GNUC__) && \
  52     !(defined(_MSC_VER) && _MSC_VER >= 1300) && \
  53     !defined(__FUNCTION__)
  54     /* no __FUNCTION__ support, still define it to avoid #ifdefs elsewhere */
  55     #define __FUNCTION__ (NULL)
  56 #endif
  57
  58 /*  ---------------------------------------------------------------------------- */
  59 /*  Debugging macros */
  60 /*  */
  61 /*  All debugging macros rely on ASSERT() which in turn calls user-defined */
  62 /*  OnAssert() function. To keep things simple, it's called even when the */
  63 /*  expression is true (i.e. everything is ok) and by default does nothing: just */
  64 /*  returns the same value back. But if you redefine it to do something more sexy */
  65 /*  (popping up a message box in your favourite GUI, sending you e-mail or */
  66 /*  whatever) it will affect all ASSERTs, FAILs and CHECKs in your code. */
  67 /*  */
  68 /*  Warning: if you don't like advice on programming style, don't read */
  69 /*  further! ;-) */
  70 /*  */
  71 /*  Extensive use of these macros is recommended! Remember that ASSERTs are */
  72 /*  disabled in final build (without __WXDEBUG__ defined), so they add strictly */
  73 /*  nothing to your program's code. On the other hand, CHECK macros do stay */
  74 /*  even in release builds, but in general are not much of a burden, while */
  75 /*  a judicious use of them might increase your program's stability. */
  76 /*  ---------------------------------------------------------------------------- */
  77
  78 /*  Macros which are completely disabled in 'release' mode */
  79 /*  */
  80 /*  NB: these functions are implemented in src/common/appcmn.cpp */
  81 #if defined(__cplusplus) && defined(__WXDEBUG__)
  82   /*
  83     This function is called whenever one of debugging macros fails (i.e.
  84     condition is false in an assertion). To customize its behaviour, override
  85     wxApp::OnAssert().
  86
  87     Parameters:
  88        szFile and nLine - file name and line number of the ASSERT
  89        szFunc           - function name of the ASSERT, may be NULL (NB: ASCII)
  90        szCond           - text form of the condition which failed
  91        szMsg            - optional message explaining the reason
  92   */
  93   extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
  94                                           int nLine,
  95                                           const char *szFunc,
  96                                           const wxChar *szCond,
  97                                           const wxChar *szMsg = NULL);
  98
  99   /*  call this function to break into the debugger unconditionally (assuming */
 100   /*  the program is running under debugger, of course) */
 101   extern void WXDLLIMPEXP_BASE wxTrap();
 102
 103   /*  generic assert macro */
 104   #define wxASSERT(cond) wxASSERT_MSG(cond, NULL)
 105
 106   /*  assert with additional message explaining it's cause */
 107   #define wxASSERT_MSG(cond, msg)                                             \
 108     if ( cond )                                                               \
 109         ;                                                                     \
 110     else                                                                      \
 111         wxOnAssert(__TFILE__, __LINE__, __FUNCTION__, _T(#cond), msg)
 112
 113   /*  special form of assert: always triggers it (in debug mode) */
 114   #define wxFAIL wxFAIL_MSG(NULL)
 115
 116   /*  FAIL with some message */
 117   #define wxFAIL_MSG(msg) wxFAIL_COND_MSG("wxAssertFailure", msg)
 118
 119   /*  FAIL with some message and a condition */
 120   #define wxFAIL_COND_MSG(cond, msg)                                          \
 121       wxOnAssert(__TFILE__, __LINE__,  __FUNCTION__, _T(cond), msg)
 122
 123   /*  an assert helper used to avoid warning when testing constant expressions, */
 124   /*  i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about */
 125   /*  expression being always true, but not using */
 126   /*  wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) */
 127   /*  */
 128   /*  NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and shouldn't be */
 129   /*      used any longer */
 130   extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
 131 #else
 132   #define wxTrap()
 133
 134   /*  nothing to do in release modes (hopefully at this moment there are */
 135   /*  no more bugs ;-) */
 136   #define wxASSERT(cond)
 137   #define wxASSERT_MSG(cond, msg)
 138   #define wxFAIL
 139   #define wxFAIL_MSG(msg)
 140   #define wxFAIL_COND_MSG(cond, msg)
 141 #endif  /* __WXDEBUG__ */
 142
 143 #ifdef __cplusplus
 144     /*  Use of wxFalse instead of false suppresses compiler warnings about testing */
 145     /*  constant expression */
 146     extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
 147 #endif
 148
 149 #define wxAssertFailure wxFalse
 150
 151 /*  NB: the following macros work also in release mode! */
 152
 153 /*
 154   These macros must be used only in invalid situation: for example, an
 155   invalid parameter (NULL pointer) is passed to a function. Instead of
 156   dereferencing it and causing core dump the function might try using
 157   CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") )
 158 */
 159
 160 /*  check that expression is true, "return" if not (also FAILs in debug mode) */
 161 #define wxCHECK(cond, rc)            wxCHECK_MSG(cond, rc, NULL)
 162
 163 /*  as wxCHECK but with a message explaining why we fail */
 164 #define wxCHECK_MSG(cond, rc, msg)   wxCHECK2_MSG(cond, return rc, msg)
 165
 166 /*  check that expression is true, perform op if not */
 167 #define wxCHECK2(cond, op)           wxCHECK2_MSG(cond, op, NULL)
 168
 169 /*  as wxCHECK2 but with a message explaining why we fail */
 170 #define wxCHECK2_MSG(cond, op, msg)                                           \
 171     if ( cond )                                                               \
 172         ;                                                                     \
 173     else                                                                      \
 174     {                                                                         \
 175         wxFAIL_COND_MSG(#cond, msg);                                          \
 176         op;                                                                   \
 177     }                                                                         \
 178     struct wxDummyCheckStruct /* just to force a semicolon */
 179
 180 /*  special form of wxCHECK2: as wxCHECK, but for use in void functions */
 181 /*  */
 182 /*  NB: there is only one form (with msg parameter) and it's intentional: */
 183 /*      there is no other way to tell the caller what exactly went wrong */
 184 /*      from the void function (of course, the function shouldn't be void */
 185 /*      to begin with...) */
 186 #define wxCHECK_RET(cond, msg)       wxCHECK2_MSG(cond, return, msg)
 187
 188 /*  ---------------------------------------------------------------------------- */
 189 /*  Compile time asserts */
 190 /*  */
 191 /*  Unlike the normal assert and related macros above which are checked during */
 192 /*  the program tun-time the macros below will result in a compilation error if */
 193 /*  the condition they check is false. This is usually used to check the */
 194 /*  expressions containing sizeof()s which cannot be tested with the */
 195 /*  preprocessor. If you can use the #if's, do use them as you can give a more */
 196 /*  detailed error message then. */
 197 /*  ---------------------------------------------------------------------------- */
 198
 199 /*
 200   How this works (you don't have to understand it to be able to use the
 201   macros): we rely on the fact that it is invalid to define a named bit field
 202   in a struct of width 0. All the rest are just the hacks to minimize the
 203   possibility of the compiler warnings when compiling this macro: in
 204   particular, this is why we define a struct and not an object (which would
 205   result in a warning about unused variable) and a named struct (otherwise we'd
 206   get a warning about an unnamed struct not used to define an object!).
 207  */
 208
 209 #define wxMAKE_UNIQUE_ASSERT_NAME           wxMAKE_UNIQUE_NAME(wxAssert_)
 210
 211 /*
 212   The second argument of this macro must be a valid C++ identifier and not a
 213   string. I.e. you should use it like this:
 214
 215     wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall );
 216
 217  It may be used both within a function and in the global scope.
 218 */
 219 #if defined(__WATCOMC__) && defined(__cplusplus)
 220     /* avoid "unused symbol" warning */
 221     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 222         class wxMAKE_UNIQUE_ASSERT_NAME { \
 223           unsigned int msg: expr; \
 224           wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
 225         }
 226 #else
 227     #define wxCOMPILE_TIME_ASSERT(expr, msg) \
 228         struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
 229 #endif
 230
 231 /*
 232    When using VC++ 6 with "Edit and Continue" on, the compiler completely
 233    mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
 234    way to make "unique" assert names by specifying a unique prefix explicitly
 235  */
 236 #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
 237
 238 #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \
 239     struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; }
 240
 241 /*  helpers for wxCOMPILE_TIME_ASSERT below, for private use only */
 242 #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits
 243
 244 /*  a special case of compile time assert: check that the size of the given type */
 245 /*  is at least the given number of bits */
 246 #define wxASSERT_MIN_BITSIZE(type, size) \
 247     wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \
 248                           wxMAKE_BITSIZE_MSG(type, size))
 249
 250 /*  ---------------------------------------------------------------------------- */
 251 /*  other miscellaneous debugger-related functions */
 252 /*  ---------------------------------------------------------------------------- */
 253
 254 /*
 255     Return true if we're running under debugger.
 256
 257     Currently this only really works under Win32 and Mac in CodeWarrior builds,
 258     it always returns false in other cases.
 259  */
 260 #ifdef __cplusplus
 261     /* ABX: check __WIN32__ instead of __WXMSW__ for the same MSWBase in any Win32 port */
 262     #if defined(__WXMAC__) || defined(__WIN32__)
 263         extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
 264     #else /*  !Mac */
 265         inline bool wxIsDebuggerRunning() { return false; }
 266     #endif /*  Mac/!Mac */
 267 #endif /* __cplusplus */
 268
 269 #endif  /*  _WX_DEBUG_H_ */