///////////////////////////////////////////////////////////////////////////// // Name: wx/debug.h // Purpose: Misc debug functions and macros // Author: Vadim Zeitlin // Modified by: // Created: 29/01/98 // RCS-ID: $Id$ // Copyright: (c) 1998 Vadim Zeitlin // Licence: wxWindows license ///////////////////////////////////////////////////////////////////////////// #ifndef _WX_DEBUG_H_ #define _WX_DEBUG_H_ #include #include // for CHAR_BIT used below #include "wx/wxchar.h" // for __TFILE__ and wxChar // ---------------------------------------------------------------------------- // Defines controlling the debugging macros // ---------------------------------------------------------------------------- // if _DEBUG is defined (MS VC++ and others use it in debug builds), define // __WXDEBUG__ too #ifdef _DEBUG #ifndef __WXDEBUG__ #define __WXDEBUG__ #endif // !__WXDEBUG__ #endif // _DEBUG // if NDEBUG is defined ( uses it), undef __WXDEBUG__ and WXDEBUG #ifdef NDEBUG #undef __WXDEBUG__ #undef WXDEBUG #endif // NDEBUG // if __WXDEBUG__ is defined, make sure that WXDEBUG is defined and >= 1 #ifdef __WXDEBUG__ #if !defined(WXDEBUG) || !WXDEBUG #undef WXDEBUG #define WXDEBUG 1 #endif // !WXDEBUG #endif // __WXDEBUG__ // ---------------------------------------------------------------------------- // Debugging macros // // All debugging macros rely on ASSERT() which in turn calls user-defined // OnAssert() function. To keep things simple, it's called even when the // expression is TRUE (i.e. everything is ok) and by default does nothing: just // returns the same value back. But if you redefine it to do something more sexy // (popping up a message box in your favourite GUI, sending you e-mail or // whatever) it will affect all ASSERTs, FAILs and CHECKs in your code. // // Warning: if you don't like advices on programming style, don't read // further! ;-) // // Extensive use of these macros is recommended! Remember that ASSERTs are // disabled in final (without __WXDEBUG__ defined) build, so they add strictly // nothing to your program's code. On the other hand, CHECK macros do stay // even in release builds, but in general are not much of a burden, while // a judicious use of them might increase your program's stability. // ---------------------------------------------------------------------------- // Macros which are completely disabled in 'release' mode // // NB: these functions are implemented in src/common/appcmn.cpp #ifdef __WXDEBUG__ /* this function may be redefined to do something non trivial and is called whenever one of debugging macros fails (i.e. condition is false in an assertion) parameters: szFile and nLine - file name and line number of the ASSERT szMsg - optional message explaining the reason */ extern void WXDLLEXPORT wxOnAssert(const wxChar *szFile, int nLine, const wxChar *szMsg = NULL); // call this function to break into the debugger uncodnitionally (assuming // the program is running under debugger, of course) extern void WXDLLEXPORT wxTrap(); /* notice the usage of else at the end of wxASSERT macro: this ensures that the following code if ( ... ) wxASSERT(...); else ... works like expected: if there were no "else", the one in the code above would be matched with a wrong "if" */ // generic assert macro #define wxASSERT(cond) if ( !(cond) ) wxOnAssert(__TFILE__, __LINE__); else // assert with additional message explaining it's cause #define wxASSERT_MSG(cond, msg) \ if ( !(cond) ) wxOnAssert(__TFILE__, __LINE__, msg); else // an assert helper used to avoid warning when testing constant expressions, // i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about // expression being always true, but not using // wxASSERT( wxAssertIsEqual(sizeof(int), 4) ) extern bool WXDLLEXPORT wxAssertIsEqual(int x, int y); #else #define wxTrap() // nothing to do in release modes (hopefully at this moment there are // no more bugs ;-) #define wxASSERT(cond) #define wxASSERT_MSG(x, m) #endif //__WXDEBUG__ // Use of wxFalse instead of FALSE suppresses compiler warnings about testing // constant expression WXDLLEXPORT_DATA(extern const bool) wxFalse; // special form of assert: always triggers it (in debug mode) #define wxFAIL wxASSERT(wxFalse) // FAIL with some message #define wxFAIL_MSG(msg) wxASSERT_MSG(wxFalse, msg) // NB: the following macros work also in release mode! /* These macros must be used only in invalid situation: for example, an invalid parameter (NULL pointer) is passed to a function. Instead of dereferencing it and causing core dump the function might try using CHECK( p != NULL ) or CHECK( p != NULL, return LogError("p is NULL!!") ) */ // check that expression is true, "return" if not (also FAILs in debug mode) #define wxCHECK(x, rc) if (!(x)) {wxFAIL; return rc; } // as wxCHECK but with a message explaining why we fail #define wxCHECK_MSG(x, rc, msg) if (!(x)) {wxFAIL_MSG(msg); return rc; } // check that expression is true, perform op if not #define wxCHECK2(x, op) if (!(x)) {wxFAIL; op; } // as wxCHECK2 but with a message explaining why we fail #define wxCHECK2_MSG(x, op, msg) if (!(x)) {wxFAIL_MSG(msg); op; } // special form of wxCHECK2: as wxCHECK, but for use in void functions // // NB: there is only one form (with msg parameter) and it's intentional: // there is no other way to tell the caller what exactly went wrong // from the void function (of course, the function shouldn't be void // to begin with...) #define wxCHECK_RET(x, msg) if (!(x)) {wxFAIL_MSG(msg); return; } // ---------------------------------------------------------------------------- // Compile time asserts // // Unlike the normal assert and related macros above which are checked during // the program tun-time the macros below will result in a compilation error if // the condition they check is false. This is usually used to check the // expressions containing sizeof()s which cannot be tested with the // preprocessor. If you can use the #if's, do use them as you can give a more // detailed error message then. // ---------------------------------------------------------------------------- /* How this works (you don't have to understand it to be able to use the macros): we rely on the fact that it is invalid to define a named bit field in a struct of width 0. All the rest are just the hacks to minimize the possibility of the compiler warnings when compiling this macro: in particular, this is why we define a struct and not an object (which would result in a warning about unused variable) and a named struct (otherwise we'd get a warning about an unnamed struct not used to define an object!). */ #define wxMAKE_ASSERT_NAME_HELPER(line) wxAssert_ ## line #define wxMAKE_ASSERT_NAME(line) wxMAKE_ASSERT_NAME_HELPER(line) #define wxMAKE_UNIQUE_ASSERT_NAME wxMAKE_ASSERT_NAME(__LINE__) #define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxMAKE_ASSERT_NAME(text) /* The second argument of this macro must be a valid C++ identifier and not a string. I.e. you should use it like this: wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall ); It may be used both within a function and in the global scope. */ #define wxCOMPILE_TIME_ASSERT(expr, msg) \ struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; } #define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \ struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; } // helpers for wxCOMPILE_TIME_ASSERT below, for private use only #define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits // a special case of compile time assert: check that the size of the given type // is at least the given number of bits #define wxASSERT_MIN_BITSIZE(type, size) \ wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \ wxMAKE_BITSIZE_MSG(type, size)) #endif // _WX_DEBUG_H_