efl/src/bin/eolian_mono/eolian/mono/marshall_type.hh

/*
 * Copyright 2019 by its authors. See AUTHORS.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef EOLIAN_MONO_MARSHALL_TYPE_HH
#define EOLIAN_MONO_MARSHALL_TYPE_HH

#include "grammar/generator.hpp"
#include "grammar/klass_def.hpp"
#include "grammar/case.hpp"

namespace eolian_mono {

namespace attributes = efl::eolian::grammar::attributes;
namespace detail {
template <typename OutputIterator, typename Context>
struct marshall_type_visitor_generate;
template <typename OutputIterator, typename Context>
struct marshall_annotation_visitor_generate;
}

/*
 * Converts a given type/parameter to the type used in the DllImport signatures.
 *
 * For example, Eina.Value can be marshaled either as an eina.Value instance through
 * CustomMarshallers if we have a ptr(Eina.Value) or through the intermediate
 * eina.ValueNative blittable struct if it is passed by value.
 *
 * For details, check marshall_type_impl.h with the actual conversion rules.
 */
struct marshall_type_generator
{
   marshall_type_generator(bool is_return = false, bool is_special_subtype = false)
     : is_return(is_return)
     , is_special_subtype(is_special_subtype)
   {}

   template <typename OutputIterator, typename Context>
   bool generate(OutputIterator sink, attributes::type_def const& type, Context const& context) const
   {
      return type.original_type.visit(detail::marshall_type_visitor_generate<OutputIterator, Context>{
        sink
        , &context
        , type.c_type
        , false
        , is_return
        , type.is_ptr
        , is_special_subtype
      });
   }
   /* Some types may require a different conversion when they are in @out parameters. */
   template <typename OutputIterator, typename Context>
   bool generate(OutputIterator sink, attributes::parameter_def const& param, Context const& context) const
   {
      return param.type.original_type.visit(detail::marshall_type_visitor_generate<OutputIterator, Context>{
        sink
        , &context
        , param.type.c_type
        , param.direction != attributes::parameter_direction::in
        , false
        , param.type.is_ptr
        , is_special_subtype
      });
   }

   bool is_return;
   bool is_special_subtype;
};

/*
 * Generates the "[MarshalAs(...)]" rules for the given type.
 *
 * For example, the CustomMarshallers definitions for String and eina.Values and the
 * boolean size defintion (Eina_Value is 1 byte, while C# bool has 4 bytes).
 */
struct marshall_annotation_generator
{
   marshall_annotation_generator(bool is_return = false)
     : is_return(is_return) {}
  
   template <typename OutputIterator, typename Context>
   bool generate(OutputIterator sink, attributes::type_def const& type, Context const& context) const
   {
      return type.original_type.visit(detail::marshall_annotation_visitor_generate<OutputIterator, Context>{sink, &context, type.c_type, false, is_return, type.is_ptr});
   }
   template <typename OutputIterator, typename Context>
   bool generate(OutputIterator sink, attributes::parameter_def const& param, Context const& context) const
   {
      return param.type.original_type.visit(detail::marshall_annotation_visitor_generate<OutputIterator, Context>{sink, &context, param.type.c_type
            , param.direction != attributes::parameter_direction::in, false, param.type.is_ptr});
   }

   bool is_return;
};

struct marshall_type_terminal
{
  marshall_type_generator const operator()(bool is_return, bool is_special_subtype = false) const
  {
    return marshall_type_generator(is_return, is_special_subtype);
  }
} const marshall_type = {};

marshall_type_generator const as_generator(marshall_type_terminal)
{
  return marshall_type_generator{};
}

struct marshall_annotation_terminal
{
  marshall_annotation_generator const operator()(bool is_return) const
  {
    return marshall_annotation_generator(is_return);
  }
} const marshall_annotation = {};

marshall_annotation_generator const as_generator(marshall_annotation_terminal)
{
  return marshall_annotation_generator{};
}


}

namespace efl { namespace eolian { namespace grammar {

template <>
struct is_eager_generator< ::eolian_mono::marshall_type_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::marshall_type_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::marshall_type_terminal> : std::true_type {};

namespace type_traits {
template <>
struct attributes_needed< ::eolian_mono::marshall_type_generator> : std::integral_constant<int, 1> {};  
template <>
struct attributes_needed< ::eolian_mono::marshall_type_terminal> : std::integral_constant<int, 1> {};  
}

template <>
struct is_eager_generator< ::eolian_mono::marshall_annotation_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::marshall_annotation_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::marshall_annotation_terminal> : std::true_type {};

namespace type_traits {
template <>
struct attributes_needed< ::eolian_mono::marshall_annotation_generator> : std::integral_constant<int, 1> {};  
template <>
struct attributes_needed< ::eolian_mono::marshall_annotation_terminal> : std::integral_constant<int, 1> {};  

}
      
} } }

#endif