Portable Binary Archive fails for -1 on AIX

[Avi Singh Bahra <avibahra@…>]

================ Main.cpp ========================= This example demonstrates a bug in portable binary format on AIX when serialising -1 that is specific only to the AIX compiler/platform (i.e HPUX/Acc and linux/gcc run without any problems) However on AIX on the restore, an exception is thrown in load_impl(..) This test consists of 1 files 1/ Main.cpp It appears that when restoring an integer of value -1, it binds to: void load(T & t){ boost::intmax_t l; load_impl(l, sizeof(T)); use cast to avoid compile time warning t = static_cast< T >(l); t = T(l); } void load_impl(boost::intmax_t & l, char maxsize); This appears to be the wrong load as the signature of load_impl() will lead to truncation ! 2/ Note You will need to pull out and compile the portable binary archive from the boost serialisation example dir.

#include <sstream> #include <ostream> #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include "portable_binary_oarchive.hpp" #include "portable_binary_iarchive.hpp" #include <boost/serialization/serialization.hpp>

using namespace std;

void save(const std::string& fileName, const int& ts, bool textArchive)

{

if ( textArchive ) std::cout << "Text archive Saving " << ts ; else std::cout << "portable binary archive Saving " << ts; try {

if (textArchive) {

std::ofstream ofs( "fred.txt" ); boost::archive::text_oarchive ar( ofs ); ar << ts;

} else {

std::ofstream ofs( fileName.c_str(), ios::binary );

portable_binary_oarchive ar(ofs);

ar << ts;

}

std::cout << " OK \n";

} catch (const boost::archive::archive_exception& ae) {

std::cout << " save " << fileName << " failed. boost::archive exception "

<< ": " << ae.what() << std::endl;

}

}

void restore(const std::string& fileName, int& restored, bool textArchive) {

if ( textArchive ) std::cout << "Text archive Restoring "; else std::cout << "portable binary archive Restoring " ;

try {

if ( textArchive ) {

std::ifstream ifs( fileName.c_str() ); boost::archive::text_iarchive ar( ifs ); ar >> restored;

} else {

std::ifstream ifs( fileName.c_str(), ios::binary ); portable_binary_iarchive ar( ifs ); ar >> restored;

}

std::cout << restored << " OK \n";

} catch ( const boost::archive::archive_exception& ae ) {

std::cout << " restore " << fileName << " failed. boost::archive exception "

<< ": " << ae.what() << std::endl;

}

}

int main() {

{

int saved = -1; save("fred.txt",saved,true);

int restored = 44; restore("fred.txt",restored,true); assert(saved == restored);

} {

int saved = -1; save("fred.txt",saved,false); int restored = 44; restore("fred.txt",restored,false); assert(saved == restored);

} return 0;

}

[Robert Ramey]

OK - looks like a compiler bug. I don't have this compiler. If you want to suggest a compiler specific workaround in the form of a patch, I would be willing to incorporate it. But lacking that there is not much I can do. You might want to contact the compiler vendor about this.

Robert Ramey

[Vicente Botet <vicente.botet@…>]

As you have access to the compiler, maybe be you can run regression test on this compiler regularly, so we can take care of this and other bugs.

[clord@…]

It's not a compiler bug. The bug is in the example code (load_impl and save_impl in portable_binary_iarchive.hpp and portable_binary_oarchive.hpp respectively). The example code should not assume that 'char' is signed -- not all compilers implement char as default-signed. I suggest changing the above functions to use 'signed char' if you're trying to represent negative char in a portable manner.

see: ​http://stackoverflow.com/questions/2054939/char-is-signed-or-unsigned-by-default