wxWidgets/include/wx/debug.h
2009-03-21 17:18:01 +00:00

315 lines
13 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/debug.h
// Purpose: Misc debug functions and macros
// Author: Vadim Zeitlin
// Created: 29/01/98
// RCS-ID: $Id$
// Copyright: (c) 1998-2009 Vadim Zeitlin <vadim@wxwidgets.org>
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DEBUG_H_
#define _WX_DEBUG_H_
#if !defined(__WXPALMOS5__) && !defined(__WXWINCE__)
#include <assert.h>
#endif // systems without assert.h
#include <limits.h> // for CHAR_BIT used below
#include "wx/chartype.h" // for __TFILE__ and wxChar
#include "wx/cpp.h" // for __WXFUNCTION__
// ----------------------------------------------------------------------------
// 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 the 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 advice on programming style, don't read
// further! ;-)
//
// Extensive use of these macros is recommended! Remember that ASSERTs are
// disabled in final build (without __WXDEBUG__ defined), 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
#if defined(__WXDEBUG__)
/*
This function is called whenever one of debugging macros fails (i.e.
condition is false in an assertion). To customize its behaviour, override
wxApp::OnAssertFailure().
Parameters:
szFile and nLine - file name and line number of the ASSERT
szFunc - function name of the ASSERT, may be NULL (NB: ASCII)
szCond - text form of the condition which failed
szMsg - optional message explaining the reason
*/
/* this version is for compatibility with wx 2.8 Unicode build only: */
extern void WXDLLIMPEXP_BASE wxOnAssert(const wxChar *szFile,
int nLine,
const char *szFunc,
const wxChar *szCond,
const wxChar *szMsg = NULL);
#if wxUSE_UNICODE
/* char versions are used by debugging macros; we have to provide
wxChar* szMsg version because it's common to use _T() in the macros
and finally, we can't use const wx(char)* szMsg = NULL, because that
would be ambiguous: */
extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
int nLine,
const char *szFunc,
const char *szCond);
extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
int nLine,
const char *szFunc,
const char *szCond,
const char *szMsg);
extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
int nLine,
const char *szFunc,
const char *szCond,
const wxChar *szMsg);
#endif /* wxUSE_UNICODE */
class WXDLLIMPEXP_FWD_BASE wxString;
class WXDLLIMPEXP_FWD_BASE wxCStrData;
/* these two work when szMsg passed to debug macro is a string,
we also have to provide wxCStrData overload to resolve ambiguity
which would otherwise arise from wxASSERT( s.c_str() ): */
extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
int nLine,
const wxString& szFunc,
const wxString& szCond,
const wxString& szMsg);
extern void WXDLLIMPEXP_BASE wxOnAssert(const wxString& szFile,
int nLine,
const wxString& szFunc,
const wxString& szCond);
extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
int nLine,
const char *szFunc,
const char *szCond,
const wxCStrData& msg);
extern void WXDLLIMPEXP_BASE wxOnAssert(const char *szFile,
int nLine,
const char *szFunc,
const char *szCond,
const wxString& szMsg);
// call this function to break into the debugger unconditionally (assuming
// the program is running under debugger, of course)
extern void WXDLLIMPEXP_BASE wxTrap();
// generic assert macro
#define wxASSERT(cond) wxASSERT_MSG(cond, (const char*)NULL)
// assert with additional message explaining its cause
// Note: some compilers will give a warning (such as
// "possible unwanted ;") when using a ";" instead of the "{}".
#define wxASSERT_MSG(cond, msg) \
if ( cond ) \
{} \
else \
wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, #cond, msg)
// special form of assert: always triggers it (in debug mode)
#define wxFAIL wxFAIL_MSG((const char*)NULL)
// FAIL with some message
#define wxFAIL_MSG(msg) wxFAIL_COND_MSG("wxAssertFailure", msg)
// FAIL with some message and a condition
#define wxFAIL_COND_MSG(cond, msg) \
wxOnAssert(__FILE__, __LINE__, __WXFUNCTION__, 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 should no
// longer be used.
extern bool WXDLLIMPEXP_BASE wxAssertIsEqual(int x, int y);
#else
#define wxTrap()
// nothing to do in release mode (hopefully at this moment there are
// no more bugs ;-)
#define wxASSERT(cond)
#define wxASSERT_MSG(cond, msg)
#define wxFAIL
#define wxFAIL_MSG(msg)
#define wxFAIL_COND_MSG(cond, msg)
#endif /* __WXDEBUG__ */
// Use of wxFalse instead of false suppresses compiler warnings about testing
// constant expression
extern WXDLLIMPEXP_DATA_BASE(const bool) wxFalse;
#define wxAssertFailure wxFalse
// NB: the following macros also work in release mode!
/*
These macros must be used only in invalid situation: for example, an
invalid parameter (e.g. a 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(cond, rc) wxCHECK_MSG(cond, rc, (const char*)NULL)
// as wxCHECK but with a message explaining why we fail
#define wxCHECK_MSG(cond, rc, msg) wxCHECK2_MSG(cond, return rc, msg)
// check that expression is true, perform op if not
#define wxCHECK2(cond, op) wxCHECK2_MSG(cond, op, (const char*)NULL)
// as wxCHECK2 but with a message explaining why we fail
#define wxCHECK2_MSG(cond, op, msg) \
if ( cond ) \
{} \
else \
{ \
wxFAIL_COND_MSG(#cond, msg); \
op; \
} \
struct wxDummyCheckStruct /* just to force a semicolon */
// 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(cond, msg) wxCHECK2_MSG(cond, return, msg)
// ----------------------------------------------------------------------------
// 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_UNIQUE_ASSERT_NAME wxMAKE_UNIQUE_NAME(wxAssert_)
/*
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.
*/
#if defined(__WATCOMC__)
/* avoid "unused symbol" warning */
#define wxCOMPILE_TIME_ASSERT(expr, msg) \
class wxMAKE_UNIQUE_ASSERT_NAME { \
unsigned int msg: expr; \
wxMAKE_UNIQUE_ASSERT_NAME() { wxUnusedVar(msg); } \
}
#else
#define wxCOMPILE_TIME_ASSERT(expr, msg) \
struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; }
#endif
/*
When using VC++ 6 with "Edit and Continue" on, the compiler completely
mishandles __LINE__ and so wxCOMPILE_TIME_ASSERT() doesn't work, provide a
way to make "unique" assert names by specifying a unique prefix explicitly
*/
#define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxCONCAT(wxAssert_, text)
#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))
// ----------------------------------------------------------------------------
// other miscellaneous debugger-related functions
// ----------------------------------------------------------------------------
/*
Return true if we're running under debugger.
Currently this only really works under Win32 and Mac in CodeWarrior builds,
it always returns false in other cases.
*/
#if defined(__WXMAC__) || defined(__WIN32__)
extern bool WXDLLIMPEXP_BASE wxIsDebuggerRunning();
#else // !Mac
inline bool wxIsDebuggerRunning() { return false; }
#endif // Mac/!Mac
#endif // _WX_DEBUG_H_