TESTING EMSCRIPTEN WITH C++11 AND BOOST

build.sh

# BUILDING BOOST FOR EMSCRIPTEN...
# REFERENCE: http://www.boost.org/doc/libs/1_58_0/more/getting_started/unix-variants.html

# TESTED WITH: BOOST 1.53 ON OSX 10.10
# DEPENDS ON: MODIFIED user-config.jam

# REQUIRED FOR iostreams
# REFERENCE: http://www.boost.org/doc/libs/1_58_0/libs/iostreams/doc/installation.html#bjam
cd $EMSCRIPTEN_PATH; ./embuilder.py build zlib
export NO_BZIP2=1

cd $BOOST_PATH
./bootstrap.sh
rm -rf stage
./b2 -a -j8 toolset=clang-emscripten link=static threading=single variant=release --with-system --with-filesystem --with-iostreams stage

rm -rf lib/emscripten
mkdir lib/emscripten
cp stage/lib/*.a lib/emscripten

unset NO_BZIP2

hello_boost.cpp

/*
 * COMPILE WITH:
 * emcc hello_boost.cpp -v -Wno-warn-absolute-paths -std=c++11 -I${BOOST_PATH} -L${BOOST_PATH}/lib/emscripten -lboost_system -lboost_filesystem -lboost_iostreams
 */

#include <boost/algorithm/string.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/filesystem.hpp>
#include <boost/iostreams/device/file_descriptor.hpp>
#include <boost/iostreams/stream.hpp>

using namespace std;
using namespace boost::filesystem;

namespace io = boost::iostreams;

int main()
{
  string input = "12345";

  if (boost::iequals(input, "foo"))
  {
    cout << input << endl;
  }
  else
  {
    auto tmp = boost::lexical_cast<int>(input);
    cout << tmp << endl;
  }

  if (true)
  {
    path documents("/Users/arielm/Documents");
    path filePath = documents / "bar.jpg";
    cout << filePath.string() << endl;
  }

  if (true)
  {
    io::file_descriptor_sink sink(fileno(stdout), io::file_descriptor_flags::never_close_handle);
    io::stream<io::file_descriptor_sink> stream(sink); 
    stream << "BAZ" << endl; 
  }

  return 0;
}

user-config.jam

# APPEND THE FOLLOWING TO ${BOOST_PATH}/tools/build/v2/user-config.jam
# REFERENCE: http://border-town.com/blog.php?id=2013-08-11_23_45_43

# ---------------------
# EMSCRIPTEN
# ---------------------

using clang : emscripten
  : emcc -v -s USE_ZLIB=1
  :   <root>${EMSCRIPTEN_PATH}
      <archiver>${EMSCRIPTEN_PATH}/emar
      <ranlib>${EMSCRIPTEN_PATH}/emranlib
      <linker>${EMSCRIPTEN_PATH}/emlink
      <cxxflags>-std=c++11
;

import type : change-generated-target-suffix ;
type.change-generated-target-suffix EXE : <toolset-clang:version>emscripten : js ;

Some open questions / issues:

A) build.sh

1. [SOLVED] Is it the best way to include zlib in term of performance, code-size and potential interferences between different systems using the lib within the same emscripten app?..

2. Somehow, ./bootstrap.sh --with-libraries=system,filesystem,iostreams is not working as intended (i.e. libs are not properly listed in the resulting project-config.jam.)

3. Does it make sense to use threading=single with ./b2?

4. [SOLVED] Somehow, stage is not working as intended with ./b2 (it can help reducing the currently long destination paths for the resulting .o and .a files...)

B) user-config.jam

1. What's the point with the change-generated-target-suffix part?..

Update regarding A1:

No need to provide the zlib source-files (i.e. via the ZLIB_SOURCE environment variable) when building boost/iostreams.

Instead: emcc should be invoked with -s USE_ZLIB=1.

Update regarding A4:

stage is working as intended with ./b2, as long as each of the libs-to-build are prefixed with --with-.

Follow-up: https://github.com/arielm/chronotext-boost