source: src/AST/Copy.hpp @ 468c5aa

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Copy.hpp -- Provides functions to copy the AST.
//
// Author           : Andrew Beach
// Created On       : Wed Jul 10 16:13:00 2019
// Last Modified By : Andrew Beach
// Last Modified On : Fri Jun 19 16:43:00 2020
// Update Count     : 1
//

#pragma once

#include "Decl.hpp"
#include "Expr.hpp"
#include "Pass.hpp"
#include "Stmt.hpp"
#include "Type.hpp"
#include <unordered_set>
#include <unordered_map>

namespace ast {

template<typename node_t>
node_t * shallowCopy( const node_t * node );
/* Create a shallow copy of the node given.
 *
 * The new node has all the same primitive field values and points to the
 * same children nodes as the parent.
 */

template<typename node_t>
node_t * deepCopy( const node_t * localRoot );
/* Create a deep copy of the tree rooted at localRoot.
 *
 * This creates a copy of every node in the sub-tree (reachable by strong
 * reference from local_root) and updates any readonly pointers on those nodes
 * that point to another node in the sub-tree to the new version of that node.
 */

class DeepCopyCore {
        std::unordered_map< const Node *, const Node * > nodeCache;
        std::unordered_set< readonly<Node> * > readonlyCache;

        template<typename node_t>
        void readonlyInsert( const readonly<node_t> * ptrptr ) {
                readonlyCache.insert( (readonly<Node> *) ptrptr );
        }

public:
        template<typename node_t>
        const node_t * previsit( const node_t * node ) {
                const node_t * copy = shallowCopy( node );
                nodeCache.insert( std::make_pair( node, copy ) );
                return copy;
        }

        void postvisit( const AggregateDecl * node ) {
                readonlyInsert( &node->parent );
        }

        void postvisit( const StructInstType * node ) {
                readonlyInsert( &node->base );
        }

        void postvisit( const UnionInstType * node ) {
                readonlyInsert( &node->base );
        }

        void postvisit( const EnumInstType * node ) {
                readonlyInsert( &node->base );
        }

        void postvisit( const TraitInstType * node ) {
                readonlyInsert( &node->base );
        }

        void postvisit( const TypeInstType * node ) {
                readonlyInsert( &node->base );
        }

        void postvisit( const ImplicitCtorDtorStmt * node ) {
                readonlyInsert( (const readonly<Stmt> *) &node->callStmt );
        }

        void postvisit( const MemberExpr * node ) {
                readonlyInsert( &node->member );
        }

        void postvisit( const VariableExpr * node ) {
                readonlyInsert( &node->var );
        }

        void postvisit( const OffsetofExpr * node ) {
                readonlyInsert( &node->member );
        }

        void postvisit( const DeletedExpr * node ) {
                readonlyInsert( &node->deleteStmt );
        }

        void readonlyUpdates() {
                for ( readonly<Node> * ptr : readonlyCache ) {
                        auto it = nodeCache.find( ptr->get() );
                        if ( nodeCache.end() != it ) {
                                *ptr = it->second;
                        }
                }
        }
};

template<typename node_t>
node_t * shallowCopy( const node_t * localRoot ) {
        return localRoot->clone();
}

template<typename node_t>
node_t * deepCopy( const node_t * localRoot ) {
        Pass< DeepCopyCore > dc;
        node_t const * newRoot = localRoot->accept( dc );
        dc.core.readonlyUpdates();
        return const_cast< node_t * >( newRoot );
}

}

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //