source: src/ResolvExpr/RenameVars.cc@ 03bf5c8

//
// 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.
//
// RenameVars.cc --
//
// Author           : Richard C. Bilson
// Created On       : Sun May 17 12:05:18 2015
// Last Modified By : Andrew Beach
// Last Modified On : Thr Jun 20 17:39:00 2019
// Update Count     : 8
//

#include <ext/alloc_traits.h>      // for __alloc_traits<>::value_type
#include <memory>                  // for allocator_traits<>::value_type
#include <sstream>                 // for operator<<, basic_ostream, ostring...
#include <utility>                 // for pair

#include "AST/ForallSubstitutionTable.hpp"
#include "AST/Pass.hpp"
#include "AST/Type.hpp"
#include "Common/PassVisitor.h"
#include "Common/ScopedMap.h"
#include "Common/SemanticError.h"  // for SemanticError
#include "RenameVars.h"
#include "SynTree/Declaration.h"   // for DeclarationWithType, TypeDecl, Dec...
#include "SynTree/Expression.h"    // for Expression
#include "SynTree/Type.h"          // for Type, TypeInstType, TraitInstType
#include "SynTree/Visitor.h"       // for acceptAll, maybeAccept

namespace ResolvExpr {

namespace {
        class RenamingData {
                int level = 0;
                int resetCount = 0;
                ScopedMap< std::string, std::string > nameMap;
        public:
                ast::ForallSubstitutionTable subs;

                void reset() {
                        level = 0;
                        ++resetCount;
                }

                void rename( TypeInstType * type ) {
                        auto it = nameMap.find( type->name );
                        if ( it != nameMap.end() ) {
                                type->name = it->second;
                        }
                }

                void openLevel( Type * type ) {
                        if ( ! type->forall.empty() ) {
                                nameMap.beginScope();
                                // renames all "forall" type names to `_${level}_${name}'
                                for ( auto td : type->forall ) {
                                        std::ostringstream output;
                                        output << "_" << resetCount << "_" << level << "_" << td->name;
                                        std::string newname( output.str() );
                                        nameMap[ td->get_name() ] = newname;
                                        td->name = newname;
                                        // ditto for assertion names, the next level in
                                        level++;
                                }
                        }
                }

                void closeLevel( Type * type ) {
                        if ( !type->forall.empty() ) {
                                nameMap.endScope();
                        }
                }

                const ast::TypeInstType * rename( const ast::TypeInstType * type ) {
                        // re-linking of base type handled by WithForallSubstitutor

                        // rename
                        auto it = nameMap.find( type->name );
                        if ( it != nameMap.end() ) {
                                // unconditionally mutate because map will *always* have different name, 
                                // if this mutates, will *always* have been mutated by ForallSubstitutor above
                                ast::TypeInstType * mut = ast::mutate( type );
                                mut->name = it->second;
                    type = mut;
                        }

                        return type;
                }

                template<typename NodeT>
                const NodeT * openLevel( const NodeT * type ) {
                        if ( type->forall.empty() ) return type;
                        
                        nameMap.beginScope();

                        // Load new names from this forall clause and perform renaming.
                        NodeT * mutType = ast::mutate( type );
                        assert( type == mutType && "mutated type must be unique from ForallSubstitutor" );
                        for ( ast::ptr< ast::TypeDecl > & td : mutType->forall ) {
                                std::ostringstream output;
                                output << "_" << resetCount << "_" << level << "_" << td->name;
                                std::string newname =  output.str();
                                nameMap[ td->name ] = newname;
                                ++level;

                                ast::TypeDecl * mutDecl = ast::mutate( td.get() );
                                assert( td == mutDecl && "mutated decl must be unique from ForallSubstitutor" );
                                mutDecl->name = newname;
                                // assertion above means `td = mutDecl;` is unnecessary
                        }
                        // assertion above means `type = mutType;` is unnecessary

                        return type;
                }

                void closeLevel( const ast::ParameterizedType * type ) {
                        if ( type->forall.empty() ) return;
                        
                        nameMap.endScope();
                }
        };

        // Global State:
        RenamingData renaming;

        struct RenameVars_old {
                void previsit( TypeInstType * instType ) {
                        renaming.openLevel( (Type*)instType );
                        renaming.rename( instType );
                }
                void previsit( Type * type ) {
                        renaming.openLevel( type );
                }
                void postvisit( Type * type ) {
                        renaming.closeLevel( type );
                }
        };
        
        struct RenameVars_new /*: public ast::WithForallSubstitutor*/ {
                #warning when old RenameVars goes away, replace hack below with global pass inheriting from WithForallSubstitutor
                ast::ForallSubstitutionTable & subs = renaming.subs;

                const ast::FunctionType * previsit( const ast::FunctionType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::StructInstType * previsit( const ast::StructInstType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::UnionInstType * previsit( const ast::UnionInstType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::TraitInstType * previsit( const ast::TraitInstType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::TypeInstType * previsit( const ast::TypeInstType * type ) {
                        return renaming.rename( renaming.openLevel( type ) );
                }
                void postvisit( const ast::ParameterizedType * type ) {
                        renaming.closeLevel( type );
                }
        };

} // namespace

void renameTyVars( Type * t ) {
        PassVisitor<RenameVars_old> renamer;
        t->accept( renamer );
}

const ast::Type * renameTyVars( const ast::Type * t ) {
        ast::Pass<RenameVars_new> renamer;
        return t->accept( renamer );
}

void resetTyVarRenaming() {
        renaming.reset();
}

} // namespace ResolvExpr

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