source: src/Virtual/Tables.cc @ 91fb850

//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Tables.cc --
//
// Author           : Andrew Beach
// Created On       : Mon Aug 31 11:11:00 2020
// Last Modified By : Andrew Beach
// Last Modified On : Tue Sep  3 14:56:00 2020
// Update Count     : 0
//

#include <SynTree/Declaration.h>
#include <SynTree/Expression.h>
#include <SynTree/Type.h>

namespace Virtual {

std::string vtableTypeName( std::string const & name ) {
        return name + "_vtable";
}

std::string instanceName( std::string const & name ) {
        return std::string("_") + name + "_instance";
}

std::string vtableInstanceName( std::string const & name ) {
        return instanceName( vtableTypeName( name ) );
}

bool isVTableInstanceName( std::string const & name ) {
        // There are some delicate length calculations here.
        return 17 < name.size() && '_' == name[0] &&
                std::string("_vtable_instance") == name.substr(1, name.size() - 17);
}

// Fuse base polymorphic declaration and forall arguments into a new type.
static StructInstType * vtableInstType(
                StructDecl * polyDecl, std::list< Expression * > && parameters ) {
        assert( parameters.size() == polyDecl->parameters.size() );
        StructInstType * type = new StructInstType(
                        Type::Qualifiers( /* Type::Const */ ), polyDecl );
        type->parameters = std::move( parameters );
        return type;
}

static ObjectDecl * makeVtableDeclaration(
                StructInstType * type, Initializer * init ) {
        std::string const & name = instanceName( type->name );
        Type::StorageClasses storage = noStorageClasses;
        if ( nullptr == init ) {
                storage.is_extern = true;
        }
        return new ObjectDecl(
                name,
                storage,
                LinkageSpec::Cforall,
                nullptr,
                type,
                init
        );
}

ObjectDecl * makeVtableForward( StructInstType * type ) {
        return makeVtableDeclaration( type, nullptr );
}

ObjectDecl * makeVtableForward(
                StructDecl * polyDecl, std::list< Expression * > && parameters ) {
        return makeVtableForward( vtableInstType( polyDecl, std::move( parameters ) ) );
}

ObjectDecl * makeVtableInstance(
                StructInstType * vtableType, Type * vobject_type, Initializer * init ) {
        StructDecl * vtableStruct = vtableType->baseStruct;
        // Build the initialization
        if ( nullptr == init ) {
                std::list< Initializer * > inits;

                // This is going to have to be run before the resolver to connect expressions.
                for ( auto field : vtableStruct->members ) {
                        if ( std::string( "parent" ) == field->name ) {
                                // This will not work with polymorphic state.
                                auto oField = strict_dynamic_cast< ObjectDecl * >( field );
                                auto fieldType = strict_dynamic_cast< PointerType * >( oField->type );
                                auto parentType = strict_dynamic_cast< StructInstType * >( fieldType->base );
                                std::string const & parentInstance = instanceName( parentType->name );
                                inits.push_back(
                                                new SingleInit( new AddressExpr( new NameExpr( parentInstance ) ) ) );
                        } else if ( std::string( "size" ) == field->name ) {
                                inits.push_back( new SingleInit( new SizeofExpr( vobject_type->clone() ) ) );
                        } else if ( std::string( "align" ) == field->name ) {
                                inits.push_back( new SingleInit( new AlignofExpr( vobject_type->clone() ) ) );
                        } else {
                                inits.push_back( new SingleInit( new NameExpr( field->name ) ) );
                        }
                }
                init = new ListInit( inits );
        // This should initialize everything except the parent pointer, the
        // size-of and align-of fields. These should be inserted.
        } else {
                assert(false);
        }
        return makeVtableDeclaration( vtableType, init );
}

ObjectDecl * makeVtableInstance(
                StructDecl * polyDecl, std::list< Expression * > && parameters,
                Type * vobject, Initializer * init ) {
        return makeVtableInstance(
                vtableInstType( polyDecl, std::move( parameters ) ), vobject, init );
}

}