Exception.cpp

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* Copyright (C) 2005, Vintela, Inc. All rights reserved.
* Copyright (C) 2006, Novell, Inc. All rights reserved.
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#include "blocxx/BLOCXX_config.h"
#include "blocxx/Exception.hpp"
#include "blocxx/StackTrace.hpp"
#include "blocxx/Format.hpp"
#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
#include "blocxx/Mutex.hpp"
#endif
#include <string.h>
// Not <cstring>, because strerror_r is not part of C or C++ standard lib,
// but is a POSIX function defined to be in <string.h>.
#include <cstdlib>
#if defined(BLOCXX_HAVE_ISTREAM) && defined(BLOCXX_HAVE_OSTREAM)
#include <istream>
#include <ostream>
#else
#include <iostream>
#endif
#include <algorithm> // for std::swap

namespace BLOCXX_NAMESPACE
{

#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
Mutex* Exception::m_mutex = new Mutex();
#endif

static void freeBuf(char** ptr)
{
   delete [] *ptr;
   *ptr = NULL;
}
char* Exception::dupString(const char* str)
{
   if (!str)
   {
      return 0;
   }
   char* rv = new (std::nothrow) char[strlen(str)+1];
   if (!rv)
   {
      return 0;
   }
   strcpy(rv, str);
   return rv;
}
Exception::Exception(const char* file, int line, const char* msg)
   : std::exception()
   , m_file(dupString(file))
   , m_line(line)
   , m_msg(dupString(msg))
   , m_subClassId(UNKNOWN_SUBCLASS_ID)
   , m_subException(0)
   , m_errorCode(UNKNOWN_ERROR_CODE)
{
#ifdef BLOCXX_ENABLE_STACK_TRACE_ON_EXCEPTIONS
   StackTrace::printStackTrace();
#endif
#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
   m_mutex->acquire();
#endif
}
Exception::Exception(int subClassId, const char* file, int line, const char* msg, int errorCode, const Exception* subException)
   : std::exception()
   , m_file(dupString(file))
   , m_line(line)
   , m_msg(dupString(msg))
   , m_subClassId(subClassId)
   , m_subException(subException ? subException->clone() : 0)
   , m_errorCode(errorCode)
{
#ifdef BLOCXX_ENABLE_STACK_TRACE_ON_EXCEPTIONS
   StackTrace::printStackTrace();
#endif
#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
   m_mutex->acquire();
#endif
}
Exception::Exception(const char* file, int line, const char* msg, int errorCode, const Exception* subException, int subClassId)
   : std::exception()
   , m_file(dupString(file))
   , m_line(line)
   , m_msg(dupString(msg))
   , m_subClassId(subClassId)
   , m_subException(subException ? subException->clone() : 0)
   , m_errorCode(errorCode)
{
#ifdef BLOCXX_ENABLE_STACK_TRACE_ON_EXCEPTIONS
   StackTrace::printStackTrace();
#endif
#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
   m_mutex->acquire();
#endif
}
Exception::Exception( const Exception& e )
    : std::exception(e)
    , m_file(dupString(e.m_file))
    , m_line(e.m_line)
    , m_msg(dupString(e.m_msg))
   , m_subClassId(e.m_subClassId)
    , m_subException(e.m_subException ? e.m_subException->clone() : 0)
   , m_errorCode(e.m_errorCode)
{
#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
    m_mutex->acquire();
#endif
}
Exception::~Exception() throw()
{
   try
   {
      delete m_subException;
      freeBuf(&m_file);
      freeBuf(&m_msg);
#if defined(BLOCXX_NON_THREAD_SAFE_EXCEPTION_HANDLING)
      m_mutex->release();
#endif
   }
   catch (...)
   {
      // don't let exceptions escape
   }
}
Exception&
Exception::operator=(const Exception& rhs)
{
    Exception(rhs).swap(*this);
    return *this;
}
void
Exception::swap(Exception& rhs)
{
   std::swap(static_cast<std::exception&>(*this), static_cast<std::exception&>(rhs));
   std::swap(m_file, rhs.m_file);
   std::swap(m_line, rhs.m_line);
   std::swap(m_msg, rhs.m_msg);
   std::swap(m_subClassId, rhs.m_subClassId);
   std::swap(m_subException, rhs.m_subException);
   std::swap(m_errorCode, rhs.m_errorCode);
}
      
const char*
Exception::type() const
{
   return "Exception";
}

int
Exception::getLine() const
{
   return m_line;
}

const char*
Exception::getMessage() const
{
   return (m_msg != NULL) ? m_msg : "";
}
const char*
Exception::getFile() const
{
   return (m_file != NULL) ? m_file : "";
}
std::ostream&
operator<<(std::ostream& os, const Exception& e)
{
   if (*e.getFile() == '\0')
   {
      os << "[no file]: ";
   }
   else
   {
      os << e.getFile() << ": ";
   }
   
   if (e.getLine() == 0)
   {
      os << "[no line] ";
   }
   else
   {
      os << e.getLine() << ' ';
   }
   
   os << e.type() << ": ";

   if (e.getErrorCode() != Exception::UNKNOWN_ERROR_CODE)
   {
      os << e.getErrorCode() << ": ";
   }
   
   if (*e.getMessage() == '\0')
   {
      os << "[no message]";
   }
   else
   {
      os << e.getMessage();
   }

   const Exception* subEx = e.getSubException();
   if (subEx)
   {
      os << " <" << *subEx << '>';
   }
   return os;
}
const char*
Exception::what() const throw()
{
   return getMessage();
}

int
Exception::getSubClassId() const
{
   return m_subClassId;
}

void
Exception::setSubClassId(int subClassId)
{
   m_subClassId = subClassId;
}

Exception*
Exception::clone() const
{
   return new(std::nothrow) Exception(*this);
}

void Exception::rethrow() const
{
   throw *this;
}

const Exception*
Exception::getSubException() const
{
   return m_subException;
}

int
Exception::getErrorCode() const
{
   return m_errorCode;
}

void
Exception::setErrorCode(int errorCode)
{
   m_errorCode = errorCode;
}

namespace ExceptionDetail
{

// HPUX, solaris have a thread safe strerror(), windows doesn't have strerror_r(), and doesn't document whether strerror() is thread safe or not.
#if defined(BLOCXX_HPUX) || defined(BLOCXX_SOLARIS) || defined(BLOCXX_WIN32) || defined(BLOCXX_NCR)

   void portable_strerror_r(int errnum, char * buf, unsigned n)
   {
      ::strncpy(buf, strerror(errnum), n);
      buf[n-1] = '\0'; // just in case...
   }

#else
   typedef int (*posix_fct)(int, char *, ::std::size_t);
   typedef char * (*gnu_fct)(int, char *, ::std::size_t);
   typedef int (*aix_fct)(int, char *, int);

   struct dummy
   {
   };

   // We make the strerror_r_wrap functions into templates so that
   // code is generated only for the one that gets used.

   template <typename Dummy>
   inline int
   strerror_r_wrap(posix_fct strerror_r, int errnum, char * buf, unsigned n,
                   Dummy)
   {
      return strerror_r(errnum, buf, n);
   }

   template <typename Dummy>
   inline int
   strerror_r_wrap(aix_fct strerror_r, int errnum, char * buf, unsigned n,
                   Dummy)
   {
      return strerror_r(errnum, buf, n);
   }

   template <typename Dummy>
   inline int
   strerror_r_wrap(gnu_fct strerror_r, int errnum, char * buf, unsigned n,
                   Dummy)
   {
      char * errstr = strerror_r(errnum, buf, n);
      if (errstr != buf)
      {
         if (errstr)
         {
            ::strncpy(buf, errstr, n);
         }
         else
         {
            return -1;
         }
      }
      return 0;
   }

   void portable_strerror_r(int errnum, char * buf, unsigned n)
   {
      int errc = strerror_r_wrap(&::strerror_r, errnum, buf, n, dummy());
      if (errc != 0)
      {
         ::strncpy(buf, "[Could not create error message for error code]", n);
      }
      buf[n-1] = '\0'; // just in case...
   }
#endif

   struct BLOCXX_COMMON_API FormatMsgImpl
   {
      String fm;
   };

   FormatMsg::FormatMsg(char const * msg, int errnum)
      : pImpl(new FormatMsgImpl)
   {
      char arr[BUFSZ];
      portable_strerror_r(errnum, arr, BUFSZ);
      char const * sarr = static_cast<char const *>(arr);
      pImpl->fm = Format("%1: %2(%3)", msg, errnum, sarr).toString();
   }

   FormatMsg::~FormatMsg()
   {
   }

   char const * FormatMsg::get() const
   {
      return pImpl->fm.c_str();
   }

} // namespace ExceptionDetail

} // end namespace BLOCXX_NAMESPACE