ExternalInterface.cc

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/*
 * ExternalInterface.cc
 *
 * Smalltalk like class library for C++
 * Interface to dynamicaly loaded libraries.
 *
 * Copyright (c) 2003-2005 Milan Cermak
 */
/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <dlfcn.h>

#include <stlib/external/ExternalInterface.h>
#include <stlib/external/EObjNotFoundError.h>
#include <stlib/external/LibNotFoundError.h>

#include <stlib/String.h>

#if !defined(NOGC)
/* It seems this declaration is missing in the GC headers */
extern "C" void *GC_dlopen(const char *libName, int flag);
#endif

namespace External {

ExternalInterface::ExternalInterface(String *library)
{
    libName = library;
    libHandler = dlopen(libName->asCString(), RTLD_NOW);
    if (libHandler == NULL) {
        (new LibraryNotFoundError(libName, new String(dlerror())))->raise();
    }
}

ExternalInterface::~ExternalInterface(void)
{
    dlclose(libHandler);
}

/* Private protocol */
void *ExternalInterface::symbol(String *selector)
{
    void *funcHandler;
    const char *errMsg;

    funcHandler = dlsym(libHandler, selector->asCString());
    if ((errMsg = dlerror()) != NULL) {
        (new ExternalObjectNotFoundError(selector, new String(errMsg)))->raiseFrom(this);
    }
    return funcHandler;
}

};

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