[Log4cplus-devel] [ log4cplus-Support Requests-3570926 ] Buffer overrun with Hello World example

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Support Requests item #3570926, was opened at 2012-09-22 21:00
Message generated for change (Comment added) made by wilx
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https://sourceforge.net/tracker/?func=detail&atid=429074&aid=3570926&group_id=40830

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Category: None
Group: v1.1.0
Status: Pending
Priority: 5
Private: No
Submitted By: https://www.google.com/accounts ()
Assigned to: Václav Zeman (wilx)
Summary: Buffer overrun with Hello World example

Initial Comment:
I'm attempting to use logforcplus in my first c++ project in over ten years, so please assume I might have done something simple wrong.  I cannot get the Hello World example working without buffer overrun errors.

I downloaded log4cplus-1.1.0-rc10. I used VS2010 to open the sln in msvc10 folder, set log4cplus project to Debug_Unicode, and compile.
I created a new project directory log4cplusDemo, with subdirectories bin, include, lib, and src.  "Bin" contains log4cplusUD.dll and pdb, "include" contains include\log4cplus, and "lib" contains log4cplusUD.lib.

I used VS2012 to create a new C++ Win32 exe in the "src" directory.  Project Properties..Configuration Properties..General..Character Set is Unicode.  Configuration Properties..C/C++..General..Additional Include Directories has a reference to "include".  Configuration Properties..Linker..General..Additional Library Directories has a reference to "lib". Linker..Input..Additional Dependencies has a reference to "log4cplusUD.lib".

Trying the hello world example resulted in a buffer overrun error. I was able to expand the macro and isolate the failing line.  Replacing it with a hardcoded string works, but causes a buffer overrun when main() exits.  What am I doing wrong?

#include "stdafx.h"

#include <log4cplus/logger.h>
#include <log4cplus/loggingmacros.h>
#include <log4cplus/configurator.h>

using namespace log4cplus;

int _tmain(int argc, _TCHAR* argv[])
{
    BasicConfigurator config;
    config.configure();
    
    Logger logger = Logger::getInstance(LOG4CPLUS_TEXT("main"));
    
	// This causes buffer overrun on this line
	// LOG4CPLUS_WARN(logger, LOG4CPLUS_TEXT("Hello, World!"));
	
	// This works (by commenting out original call to .str() and sending a string directly),
	// but buffer overflow error occurs on return statement.
	do {                                                            
        log4cplus::Logger const & _l                                    
            = log4cplus::detail::macros_get_logger (logger);            
		// I can't figure out this macro, and it's just checking if the desired log level is enabled so comment out
		//     if (LOG4CPLUS_MACRO_LOGLEVEL_PRED (
			//_l.isEnabledFor (log4cplus::logLevel), logLevel)) {
    
		log4cplus::tostringstream & _log4cplus_buf                  
                = log4cplus::detail::get_macro_body_oss ();             
            _log4cplus_buf << LOG4CPLUS_TEXT("Hello, World!");                                 
			log4cplus::detail::macro_forced_log (_l,                    
				log4cplus::WARN_LOG_LEVEL, 				
				// This causes buffer overflow error, replace with string directly
				//_log4cplus_buf.str(),
				L"Hello world!",
                __FILE__,
				__LINE__, 
				LOG4CPLUS_MACRO_FUNCTION ()
				);       
		//}
    } while (0);
	
    getchar();
	return 0;
}

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>Comment By: Václav Zeman (wilx)
Date: 2012-09-23 22:42

Message:
The code should work in both VS 2010 and VS 2012 but mixing binaries from
different VS versions is not possible. I will try to take a look at the
problem but first I will have to get VS 2012.

----------------------------------------------------------------------

Comment By: https://www.google.com/accounts ()
Date: 2012-09-23 20:10

Message:
Building log4cplus in VS 2012 didn't help (yes, it does open the VS2010
solution just fine).  I moved hello world to VS 2010 and it works, even
with the VS 2012 compiled log4cplus, which I thought was interesting. 
After digging through the project options for VS 2012 hello world, I found
Configuration Properties..General..Platform Toolkit.  It was set to VS 2012
(v110), setting it to VS 2010 (v100) made the buffer overrun disappear, and
I was able run hello world without any macro hacking.  Unfortunately this
means choosing between using the new C++11 libraries or log4cplus in my
project.

I flipped it back to v110 and experimented some. The buffer overrun at the
end of main() in the code I first posted is actually coming from the
declaration of BasicConfigurator.  Using the  v110 toolset, simply doing
this:

int _tmain(int argc, _TCHAR* argv[])
{
    BasicConfigurator config;
	return 0;
}

 causes the overrun at the return statement.  I thought you might want to
know for when you start adding C++11 support.

Thanks for your time and advice on this, I really appreciate it. Your
project looked great and I'm disappointed I'm not going to be able to use
it.

----------------------------------------------------------------------

Comment By: Václav Zeman (wilx)
Date: 2012-09-22 22:48

Message:
AFAIK, you cannot do that. Trying to combine VS 2010 built library and VS
2012 compiled executable, in general, does not work. Build log4cplus using
VS 2012 as well. I have not tried but there should be no problem opening
the VS 2010 solution in VS 2012 and building it there.

----------------------------------------------------------------------

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