[Boost-users] Q: exceptions and -fPIC

From: Andrey Nechypurenko (andreynech_at_[hidden])
Date: 2003-09-19 07:16:58

Hi,

I am on the following platform:

Linux 2.6.0-test5 #11 Wed Sep 10 20:28:31 CEST 2003 i686 unknown

Reading specs from /usr/lib/gcc-lib/i386-slackware-linux/3.2.2/specs
Configured with: ../gcc-3.2.2/configure --prefix=/usr --enable-shared
--enable-threads=posix --enable-__cxa_atexit --disable-checking --with-gnu-ld
--verbose --target=i386-slackware-linux --host=i386-slackware-linux
Thread model: posix
gcc version 3.2.2

Boost version 1.30.2 compiled with: bjam "-sTOOLS=gcc"

I have a question regarding the following boost::filesystem use case:

  try
  {
    for(fs::directory_iterator dir_itr(full_path);
      dir_itr != end_iter; ++dir_itr )
    {
      // use dir_itr
    }
  }
  catch(const std::exception &ex)
  {
    std::cout << ex.what() << std::endl;
  }

In case of full_path pointed to the directory without read permissions the
corresponding exception is thrown and catched in the catch block.

My problem is that if I compile my application with -fPIC option, I am unable
to catch the exception anymore and the program is simply aborted. I need to 
use -fPIC because of other library which has own build system and if I follow
suggested guidlines for Makefile, I get -fPIC automatically. 

I would verry appreciate if somebody could tell me are there any ways to make
the code mentioned above work when it is compiled with -fPIC? Should I
recompile boost with -fPIC? If yes, what is the right place to set this
parameter? BTW how it is supposed to write a shared library which includes 
boost code? As I understand, than my code must be compiled with -fPIC... 

Thanks,
Andrey.

P.S.
Here is example I am using and the makefile:

// ttt.cpp
#include <iostream>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>

namespace fs = boost::filesystem;

int main(int argc, char **argv)
{
  try
  {
    fs::path full_path =
      fs::system_complete(fs::path(argv[1], fs::native));
    fs::directory_iterator end_iter;
    for(fs::directory_iterator dir_itr(full_path);
      dir_itr != end_iter; ++dir_itr )
    {
      std::cout << dir_itr->leaf() << std::endl;
    }
  }
  catch(const std::exception &ex)
  {
    std::cout << ex.what() << std::endl;
  }

  return 0;
}

Makefile:

CPPFLAGS        := -I/usr/local/src/boost
LDFLAGS         :=
-L/usr/local/src/boost/libs/filesystem/build/bin/libboost_filesystem.a/gcc/debug/runtime-link-dynamic/
LIBS            := $(LIBS) -lboost_filesystem

ttt: ttt.cpp
        c++ $(CPPFLAGS) -g  -ftemplate-depth-128 -fPIC -Wall $(LDFLAGS) -o $@
ttt.cpp $(LIBS)

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