module_definition.cpp

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2025 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */
 
#include "python_common.h"
#include "module_definition.h"
#include "enum_definition.h"
 
 
#if PY_VERSION_HEX < 0x030a0000 // < 3.10
 
namespace
{
 
int PyModule_AddObjectRef(PyObject* module, const char* name, PyObject* value)
{
    Py_XINCREF(value);
    if (PyModule_AddObject(module, name, value) != 0)
    {
        Py_XDECREF(value);
        return -1;
    }
    return 0;
}
 
}
 
#endif
 
namespace lass
{
namespace python
{
 
ModuleDefinition::ModuleDefinition(const char* name, const char* doc):
    module_(0),
    isInjected_(false)
{
    PyModuleDef def = {
        PyModuleDef_HEAD_INIT,
        0, /* m_name */
        0, /* m_doc */
        0, /* m_size */
        0, /* m_methods */
        0, /* m_reload */
        0, /* m_traverse */
        0, /* m_clear */
        0, /* m_free */
    };
    def_ = def;
 
    setName(name);
    setDoc(doc);
}
 
namespace experimental
{
    typedef std::unique_ptr<char[]> TScopedCString;
    void assignScopedCString(TScopedCString& out, const char* in)
    {
        if (in)
        {
            const size_t n = strlen(in) + 1;
            TScopedCString temp(new char[n]);
            memcpy(temp.get(), in, n);
            out.swap(temp);
        }
        else
        {
            out.reset();
        }
    }
}
 
void ModuleDefinition::setName(const char* name)
{
    experimental::assignScopedCString(name_, name);
}
 
void ModuleDefinition::setDoc(const char* doc)
{
    experimental::assignScopedCString(doc_, doc);
}
 
/** callback called at start of module injection
 */
void ModuleDefinition::setPreInject(const TPreInject& callback)
{
    preInject_ = callback;
}
 
/** callback called at end of module injection, with module as parameter
 */
void ModuleDefinition::setPostInject(const TPostInject& callback)
{
    postInject_ = callback;
}
 
/** new-style class addition.
 *
 *  This function adds a class definition to a table that will be injected when the module is.
 */
void ModuleDefinition::addClass(impl::ClassDefinition& classDef)
{
    LASS_ASSERT(!isInjected_);
    classes_.push_back(&classDef);
}
 
void ModuleDefinition::addEnum(EnumDefinitionBase* enumDef)
{
    LASS_ASSERT(!isInjected_);
    enums_.push_back(enumDef);
}
 
void ModuleDefinition::addObject(PyObject* object, const char* name)
{
    LASS_ASSERT(!isInjected_);
    NamedObject *tempObject = new NamedObject;
    experimental::assignScopedCString(tempObject->name, name);
    tempObject->object = object;
    objects_.push_back(tempObject);
}
 
void ModuleDefinition::addLong(long object, const char* name)
{
    LASS_ASSERT(!isInjected_);
    LongObject *tempObject = new LongObject;
    experimental::assignScopedCString(tempObject->name, name);
    tempObject->object = object;
    longObjects_.push_back(tempObject);
}
 
void ModuleDefinition::addString(const char* object, const char* name)
{
    LASS_ASSERT(!isInjected_);
    StringObject* tempObject = new StringObject;
    experimental::assignScopedCString(tempObject->name, name);
    experimental::assignScopedCString(tempObject->object, object);
    stringObjects_.push_back(tempObject);
}
 
 
void ModuleDefinition::addFunctionDispatcher(
        PyCFunction dispatcher, const char* name, const char* doc, PyCFunction& overloadChain)
{
    TMethods::iterator i = ::std::find_if(methods_.begin(), methods_.end(), impl::NamePredicate(name));
    if (i == methods_.end())
    {
        methods_.push_back(impl::createPyMethodDef(name, dispatcher, METH_VARARGS , doc));
        overloadChain = 0;
    }
    else
    {
        overloadChain = i->ml_meth;
        i->ml_meth = dispatcher;
    };
}
 
 
void ModuleDefinition::injectLong(const char* name, long value)
{
    LASS_ENFORCE_POINTER(module_);
    PyModule_AddIntConstant(module_, name, value);
}
 
 
void ModuleDefinition::injectString(const char* name, const char* value)
{
    LASS_ENFORCE_POINTER(module_);
    PyModule_AddStringConstant(module_, name, value);
}
 
 
/** old-style class injection.
 *
 *  This function can injects a class in an already-injected module
 *  @deprecated
 */
bool ModuleDefinition::injectClass(impl::ClassDefinition& classDef)
{
    LASS_ENFORCE_POINTER(module_);
    const char* shortName = classDef.name(); // finalizePyType will expand tp_name with module name.
    PyObject* type = classDef.freezeDefinition(module_);
    return PyModule_AddObjectRef(module_, const_cast<char*>(shortName), type) == 0;
}
 
 
 
PyObject* ModuleDefinition::inject()
{
    PyObject* mod = doInject();
    if (!mod)
    {
        chainErrFormat(PyExc_ImportError, "Failed to import '%s'", name_.get());
    }
    return mod;
}
 
 
 
PyObject* ModuleDefinition::doInject()
{
    if (isInjected_)
    {
        // this can happen when the module was imported before, and then removed
        // from sys.modules, and then re-imported. In that case, the module will
        // be injected again. The only thing we can do is to return the same
        // module again.
        Py_INCREF(module_);
        return module_;
    }
    if (!module_)
    {
        LASS_ASSERT(name_.get());
        preInject_();
        methods_.push_back(impl::createPyMethodDef(0, 0, 0, 0));
        Py_Initialize();
        def_.m_name = name_.get();
        def_.m_doc = doc_.get();
        def_.m_methods = &methods_[0];
        module_ = PyModule_Create(&def_);
        if (!module_)
        {
            return nullptr;
        }
    }
    for (auto def: classes_)
    {
        if (!injectClass(*def) != 0)
        {
            return nullptr;
        }
    }
    for (auto def: enums_)
    {
        PyObject* enumType = def->freezeDefinition(name_.get(), nullptr);
        if (PyModule_AddObjectRef(module_, def->name(), enumType) != 0)
        {
            return nullptr;
        }
    }
    for (TObjects::const_iterator obj = objects_.begin(); obj != objects_.end(); ++obj)
    {
        PyModule_AddObject(module_, (*obj)->name.get(), (*obj)->object);
    }
    for (TLongObjects::const_iterator obj = longObjects_.begin(); obj != longObjects_.end(); ++obj)
    {
        if (PyModule_AddIntConstant(module_, (*obj)->name.get(), (*obj)->object) != 0)
        {
            return nullptr;
        }
    }
    for (TStringObjects::const_iterator obj = stringObjects_.begin(); obj != stringObjects_.end(); ++obj)
    {
        if (PyModule_AddStringConstant(module_, (*obj)->name.get(), (*obj)->object.get()) != 0)
        {
            return nullptr;
        }
    }
    postInject_(module_);
    isInjected_ = true;
    Py_INCREF(module_);
    return module_;
}
 
}
}
 
// EOF