Strange output from boost::exception diagnostic_information
-------------------------------------------------------------------------------- I've been having a look at the diagnostic_information function in the boost exception library, but seem to be getting a strangely formatted output. The code I'm using is as follows Code: #include <boost/exception/diagnostic_information.hpp> #include <stdexcept> #include <iostream> void myerror(){ throw boost::enable_error_info(std::range_error("blah")); } int main(){ try{ myerror(); } catch(boost::exception & e){ std::cerr << diagnostic_information(e) << std::endl; } return 0; }The output is as follows: Quote: Throw in function (unknown) Dynamic exception type: N5boost16exception_detail19error_info_injectorISt1 1range_errorEE std::exception::what: blah What I don't understand is why I'm getting N5, 16, 19, ISt11 and EE between the details of the exception type. To rule out my code, I compiled the example_io.cpp file provided in the boost example documentation and I'm getting a similar output. Does anyone what is causing the strange characters displayed? I'm running Ubuntu 9.10 and the version of g++ is 4.4.1 -- View this message in context: http://old.nabble.com/Strange-output-from-boost%3A%3Aexception-diagnostic_in... Sent from the Boost - Users mailing list archive at Nabble.com.
On Sun, Jan 31, 2010 at 4:41 AM, pholding <pholding@blueyonder.co.uk> wrote:
Throw in function (unknown) Dynamic exception type: N5boost16exception_detail19error_info_injectorISt1 1range_errorEE std::exception::what: blah
Your code is correct and the output is correct too. The weird type name you're seeing is the mangled C++ identifier, see http://en.wikipedia.org/wiki/Name_mangling#Name_mangling_in_C.2B.2B. Note that by design, the diagnostic_information message is not intended to be user-friendly. However I will accept any patches that improve the output from diagnostic_information, not only in terms of prettifying the mangled names but also including more diagnostic information, even if it is platform-specific. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode
On Sunday 31 January 2010 13:37:08 Emil Dotchevski wrote:
Note that by design, the diagnostic_information message is not intended to be user-friendly. However I will accept any patches that improve the output from diagnostic_information, not only in terms of prettifying the mangled names but also including more diagnostic information, even if it is platform-specific.
Is there a reason not use the following directly? http://www.boost.org/doc/libs/1_41_0/boost/units/detail/utility.hpp The above produces pretty clean demangling on gcc; I have used variants of it in my projects with plenty of success. Regards, Ravi
Ravi wrote:
On Sunday 31 January 2010 13:37:08 Emil Dotchevski wrote:
Note that by design, the diagnostic_information message is not intended to be user-friendly. However I will accept any patches that improve the output from diagnostic_information, not only in terms of prettifying the mangled names but also including more diagnostic information, even if it is platform-specific.
Is there a reason not use the following directly? http://www.boost.org/doc/libs/1_41_0/boost/units/detail/utility.hpp
The above produces pretty clean demangling on gcc; I have used variants of it in my projects with plenty of success.
On the OP's platform, one would ordinarily use the stand-alone c++filt program. c++filt fails on this particular example, though, for reasons that escape me. (I happen to be sitting at a machine with the same OS and compiler versions as the OP.) Thanks for pointing out the Boost version; I didn't know about it. Since the OP is using GCC, the following will also work: char* demangle(char const* const name, int* const status) { typedef char* buffer_pointer_t; typedef std::size_t* length_pointer_t; return abi::__cxa_demangle( name , buffer_pointer_t( ) , length_pointer_t( ) , status); } For example, wrapping this function in a c++filt work-alike: ./main N5boost16exception_detail19error_info_injectorISt11range_errorEE boost::exception_detail::error_info_injector<std::range_error> I've just posted sample code on GitHub; see demangle.hh and main.cc: http://github.com/jeffs/jms/tree/master/src/jms/demangle
AMDG Jeff Schwab wrote:
Thanks for pointing out the Boost version; I didn't know about it. Since the OP is using GCC, the following will also work:
The version in Boost.Units effectively does the same thing wrapped in #ifdefs to make it compile for non-GCC.
char* demangle(char const* const name, int* const status) { typedef char* buffer_pointer_t; typedef std::size_t* length_pointer_t; return abi::__cxa_demangle( name , buffer_pointer_t( ) , length_pointer_t( ) , status); }
For example, wrapping this function in a c++filt work-alike: ./main N5boost16exception_detail19error_info_injectorISt11range_errorEE boost::exception_detail::error_info_injector<std::range_error>
I've just posted sample code on GitHub; see demangle.hh and main.cc: http://github.com/jeffs/jms/tree/master/src/jms/demangle
In Christ, Steven Watanabe
On Sun, Jan 31, 2010 at 12:01 PM, Ravi <lists_ravi@lavabit.com> wrote:
On Sunday 31 January 2010 13:37:08 Emil Dotchevski wrote:
Note that by design, the diagnostic_information message is not intended to be user-friendly. However I will accept any patches that improve the output from diagnostic_information, not only in terms of prettifying the mangled names but also including more diagnostic information, even if it is platform-specific.
Is there a reason not use the following directly? http://www.boost.org/doc/libs/1_41_0/boost/units/detail/utility.hpp
OK, trunk revision 59398 uses boost/units/detail/utility.hpp for demangling type names used in diagnostic_information (except under rtti=off). We should probably do a mini-review and make this an official utility function. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode
participants (5)
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Emil Dotchevski -
Jeff Schwab -
pholding -
Ravi -
Steven Watanabe