wxWidgets/include/wx/debug.h
Vadim Zeitlin 2b5f62a0b2 merged 2.4 branch into the trunk
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18040 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2002-12-04 14:11:26 +00:00

214 lines
8.6 KiB
C

/////////////////////////////////////////////////////////////////////////////
// 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 <zeitlin@dptmaths.ens-cachan.fr>
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DEBUG_H_
#define _WX_DEBUG_H_
#include <assert.h>
#include <limits.h> // 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 (<assert.h> 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 *szCond,
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();
// helper function used to implement wxASSERT and wxASSERT_MSG
//
// note using "int" and not "bool" for cond to avoid VC++ warnings about
// implicit conversions when doing "wxAssert( pointer )" and also use of
// "!!cond" below to ensure that everything is converted to int
extern void WXDLLEXPORT wxAssert(int cond,
const wxChar *szFile,
int nLine,
const wxChar *szCond,
const wxChar *szMsg = NULL) ;
// generic assert macro
#define wxASSERT(cond) wxAssert(!!(cond), __TFILE__, __LINE__, _T(#cond))
// assert with additional message explaining it's cause
#define wxASSERT_MSG(cond, msg) \
wxAssert(!!(cond), __TFILE__, __LINE__, _T(#cond), msg)
// 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) )
//
// NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and shouldn't be
// used any longer
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;
#define wxAssertFailure wxFalse
// special form of assert: always triggers it (in debug mode)
#define wxFAIL wxASSERT(wxAssertFailure)
// FAIL with some message
#define wxFAIL_MSG(msg) wxASSERT_MSG(wxAssertFailure, 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_