source: src/ControlStruct/HoistControlDecls.cpp @ 41870a5

//
// 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.
//
// HoistControlDecls.cpp -- Desugar Cforall control structures.
//
// Author           : Andrew Beach
// Created On       : Fri Dec  3 15:34:00 2021
// Last Modified By : Peter A. Buhr
// Last Modified On : Tue Feb  1 18:59:47 2022
// Update Count     : 25
//

#include "HoistControlDecls.hpp"

#include "AST/Decl.hpp"
#include "AST/Pass.hpp"
#include "AST/TranslationUnit.hpp"
using namespace ast;

namespace ControlStruct {

template<typename StmtT>
const Stmt * hoist( const StmtT * stmt ) {
        // If no hoisting is needed, then make no changes.

        if ( stmt->inits.size() == 0 ) {                                        // no declarations ?
                // if ( /* no conditional declarations */ ...  ) ...
                return stmt;
        } // if

        // Put hoist declarations and modified statement in a compound statement.

        CompoundStmt * block = new CompoundStmt( stmt->location ); // create empty compound statement
        //    {}

        for ( const Stmt * next : stmt->inits ) {                       // link conditional declarations into compound
                block->kids.push_back( next );
        }
        //    if ( int x = f(), y = g(); ... ) ...
        // link declarations into compound statement
        //    {
        //         int x = f();
        //         int y = g();
        //    }

        StmtT * mutStmt = mutate( stmt );                                       // create mutate handle to change statement
        mutStmt->inits.clear();                                                         // remove declarations
        //    if ( ... ) ...

        block->kids.push_back( mutStmt );                                       // link modified statement into compound
        //    {
        //        int x = f();
        //        int y = g();
        //        if ( ... ) ...
        //    }
        return block;
}

struct hoistControlDeclsCore {
        // Statements with declarations in conditional.
        const Stmt * postvisit( const IfStmt * stmt ) {
                return hoist<IfStmt>( stmt );
        }
        const Stmt * postvisit( const ForStmt * stmt ) {
                return hoist<ForStmt>( stmt );
        }
        const Stmt * postvisit( const WhileDoStmt * stmt ) {
                return hoist<WhileDoStmt>( stmt );
        }
};

// Hoist initialization out of for statements.
void hoistControlDecls( TranslationUnit & translationUnit ) {
        Pass<hoistControlDeclsCore>::run( translationUnit );
}

} // namespace ControlStruct

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