Backtrace.cc

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\---------------------------------------------------------------------*/
#include <execinfo.h>
#include <cxxabi.h>

#include <iostream>
#include "zypp/base/LogTools.h"
#include "zypp/base/String.h"
#include "zypp/base/Backtrace.h"

using std::endl;

namespace zypp
{
  std::ostream & dumpBacktrace( std::ostream & stream_r )
  {
    // get void*'s for all entries on the stack
    static const size_t arraySize = 50;
    void *array[arraySize];
    size_t size = ::backtrace( array, arraySize );

    // Print out all frames to stderr. Separate sigsegvHandler stack
    // [dumpBacktrace][sigsegvHandler][libc throwing] from actual
    // code stack.
    char ** messages = ::backtrace_symbols( array, size );
    if ( messages )
    {
      static const size_t handlerStack = 3; // [dumpBacktrace][sigsegvHandler][libc throwing]
      static const size_t first = 0;
      for ( size_t i = first; i < size; ++i )
      {
        char * mangled_name = 0;
        char * offset_begin = 0;
        char * offset_end = 0;

        // find parentheses and +address offset surrounding mangled name
        for ( char * p = messages[i]; *p; ++p )
        {
          if ( *p == '(' )
          {
            mangled_name = p;
          }
          else if ( *p == '+' )
          {
            offset_begin = p;
          }
          else if ( *p == ')' )
          {
            offset_end = p;
            break;
          }
        }

        int btLevel = i-handlerStack; // negative level in sigsegvHandler
        if ( i > first )
        {
          stream_r << endl;
          if ( btLevel == 0 )
            stream_r << "vvvvvvvvvv----------------------------------------" << endl;
        }
        stream_r << "[" << (btLevel<0 ?"hd":"bt") << "]: (" << btLevel << ") ";

        // if the line could be processed, attempt to demangle the symbol
        if ( mangled_name && offset_begin && offset_end && mangled_name < offset_begin )
        {
          *mangled_name++ = '\0';
          *offset_begin++ = '\0';
          *offset_end++ = '\0';

          int status;
          char * real_name = ::abi::__cxa_demangle( mangled_name, 0, 0, &status );

          // if demangling is successful, output the demangled function name
          if ( status == 0 )
          {
            stream_r << messages[i] << " : " << real_name << "+" << offset_begin << offset_end;
          }
          // otherwise, output the mangled function name
          else
          {
            stream_r << messages[i] << " : " << mangled_name << "+" << offset_begin << offset_end;
          }
          ::free( real_name );
        }
        else
        {
          // otherwise, print the whole line
          stream_r << messages[i];
        }
      }
      ::free( messages );
    }
    return stream_r;
  }

} // namespace zypp