[exception] What's wrong with boost::get_error_info?
Dear boost community, I'm really new to using the boost library. Whatever, the first part I want to use is boost::exception. But already there start my problems: I'm using 'boost::get_error_info<boost::throw_file>( myBoostException )' to retrieve the file name where my exception was thrown. The problem is that the returned 'const char*' pointer contains several wild characters at its end. It seems that the null-termination get lost somehow, somewhere. The same is with 'boost::throw_function' and the string returned by 'boost::diagnostic_information( myBoostException )'! For example, that is what I get from boost::diagnostic_information: ".\myFile.cppÍýýýý««««««««îþ(134): Throw in function MyClass::DoSomething()ÍÍÍÍÍÍ^ñ6 Dynamic exception type: class MyBoostException" That's really strange because the strings are correctly stored to the boost::exception class attributes 'throw_function_' and 'throw_file_'. So what do I wrong??? I would be so thankful when anyone could help me! Following some detailed information: - plattfrom: Windows XP SP3 - compiler: MS VC++ 8 - character set: multi-byte - boost version: Release 1.37.0 code snippet for throwing my exception: throw MyBoostException() << boost::throw_file( __FILE__ ) << boost::throw_line( __LINE__ ) << boost::throw_function( "MyClass::DoSomething()" ); code snippet for catching my exception: catch( MyBoostException& myBoostException ) { std::string info = boost::diagnostic_information( myBoostException ); const char* string = info.c_str(); } My best regards, Markus
2009/5/29 Markus Schweiß <M.Schweiss@cs-group.de>:
Dear boost community,
I'm really new to using the boost library. Whatever, the first part I want to use is boost::exception. But already there start my problems:
I'm using 'boost::get_error_info<boost::throw_file>( myBoostException )' to retrieve the file name where my exception was thrown. The problem is that the returned 'const char*' pointer contains several wild characters at its end. It seems that the null-termination get lost somehow, somewhere.
The same is with 'boost::throw_function' and the string returned by 'boost::diagnostic_information( myBoostException )'!
For example, that is what I get from boost::diagnostic_information: ".\myFile.cppÍýýýý««««««««îþ(134): Throw in function MyClass::DoSomething()ÍÍÍÍÍÍ^ñ6 Dynamic exception type: class MyBoostException"
That's really strange because the strings are correctly stored to the boost::exception class attributes 'throw_function_' and 'throw_file_'.
So what do I wrong??? I would be so thankful when anyone could help me!
Following some detailed information: - plattfrom: Windows XP SP3 - compiler: MS VC++ 8 - character set: multi-byte - boost version: Release 1.37.0
code snippet for throwing my exception:
throw MyBoostException() << boost::throw_file( __FILE__ ) << boost::throw_line( __LINE__ ) << boost::throw_function( "MyClass::DoSomething()" );
code snippet for catching my exception:
catch( MyBoostException& myBoostException ) { std::string info = boost::diagnostic_information( myBoostException ); const char* string = info.c_str(); }
Long shot, but it looks like you have ABI conflict of some sort. Could you post a simple, complete program that demonstrates your problems? Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode
2009/5/30 Emil Dotchevski <emildotchevski@gmail.com>:
Long shot, but it looks like you have ABI conflict of some sort. Could you post a simple, complete program that demonstrates your problems?
Here is the complete sourcecode of a Win32 console application that reproduces my problem. And shame on me, I forgot to mention that my application as well as the Boost libraries uses STLport version 5.0.2 #define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers #include <stdio.h> #include <tchar.h> #include <boost/exception.hpp> class MyBoostException : public boost::exception { public: MyBoostException() { /*do nothing*/ }; virtual ~MyBoostException() { /*do nothing*/ }; }; void DoSomething() { throw MyBoostException() << boost::throw_file( _T(__FILE__) ) << boost::throw_line( __LINE__ ) << boost::throw_function( _T("DoSomething()") ); } int _tmain( int argc, _TCHAR* argv[] ) { try { DoSomething(); } catch( MyBoostException& ex ) { boost::shared_ptr<const int> pLine = boost::get_error_info<boost::throw_line>(ex); boost::shared_ptr<const char* const> pMethod = boost::get_error_info<boost::throw_function>(ex); const char* sMethod = *pMethod; boost::shared_ptr<const char* const> pFile = boost::get_error_info<boost::throw_file>(ex); const char* sFile= *pFile; std::string info = boost::diagnostic_information( ex ); const char* sString = info.c_str(); } return 0; }
2009/6/2 Markus Schweiß <M.Schweiss@cs-group.de>:
2009/5/30 Emil Dotchevski <emildotchevski@gmail.com>:
Long shot, but it looks like you have ABI conflict of some sort. Could you post a simple, complete program that demonstrates your problems?
Here is the complete sourcecode of a Win32 console application that reproduces my problem. And shame on me, I forgot to mention that my application as well as the Boost libraries uses STLport version 5.0.2
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers #include <stdio.h> #include <tchar.h> #include <boost/exception.hpp>
class MyBoostException : public boost::exception { public: MyBoostException() { /*do nothing*/ }; virtual ~MyBoostException() { /*do nothing*/ }; };
void DoSomething() { throw MyBoostException() << boost::throw_file( _T(__FILE__) ) << boost::throw_line( __LINE__ ) << boost::throw_function( _T("DoSomething()") ); }
int _tmain( int argc, _TCHAR* argv[] ) { try { DoSomething(); } catch( MyBoostException& ex ) {
boost::shared_ptr<const int> pLine = boost::get_error_info<boost::throw_line>(ex);
boost::shared_ptr<const char* const> pMethod = boost::get_error_info<boost::throw_function>(ex); const char* sMethod = *pMethod;
boost::shared_ptr<const char* const> pFile = boost::get_error_info<boost::throw_file>(ex); const char* sFile= *pFile;
std::string info = boost::diagnostic_information( ex ); const char* sString = info.c_str();
} return 0; }
I am puzzled, but here is another guess. Boost::throw_line, boost::throw_function and boost::throw_file have special handling in Boost Exception; adding them to exceptions does not use anything from STL. So here is something to try: print *pLine, sMethod and sFile directly. If you get correct strings, then the problem could be in some interference between STLport and std::ostringstream. Step into boost::diagnostic_information and see what is passed into std::ostringstream's operator<<. If the data entering it is good but the output from .str() is bad, it's definitely an issue with STLport's installation. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode
2009/6/2 Emil Dotchevski <emildotchevski@gmail.com>:
I am puzzled, but here is another guess.
Boost::throw_line, boost::throw_function and boost::throw_file have special handling in Boost Exception; adding them to exceptions does not use anything from STL. So here is something to try: print *pLine, sMethod and sFile directly. If you get correct strings, then the problem could be in some interference between STLport and std::ostringstream. Step into boost::diagnostic_information and see what is passed into std::ostringstream's operator<<. If the data entering it is good but the output from .str() is bad, it's definitely an issue with STLport's installation.
It seems that std::ostringstream has nothing to do with my problems. But the STLport installation might still be the guilty party. I detected the source of annoyance within file 'get_error_info.hpp', at line 49 respectively 67, where a string wrapper instance is created: shared_ptr<strwrap> s(new strwrap(x.throw_function_)); respectively shared_ptr<strwrap> s(new strwrap(x.throw_file_)); Initialization of attribute 'str' (a std::string) within strwrap's c'tor, is the point where the null-termination get lost. For now I try to compile my application with a newer STLport version, respectively without any STLport, to see what happen. Progress will be reported soon...
2009/6/3 Markus Schweiß <M.Schweiss@cs-group.de>:
For now I try to compile my application with a newer STLport version, respectively without any STLport, to see what happen. Progress will be reported soon...
I also recommend upgrading to the newest version of Boost; get_error_info now returns a raw pointer, not shared_ptr. It will probably save you time to make the switch to this new behavior sooner rather than later. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode
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Markus Schweiß