source: src/ResolvExpr/ResolveTypeof.cc @ 0dd9a5e

//
// 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.
//
// ResolveTypeof.cc --
//
// Author           : Richard C. Bilson
// Created On       : Sun May 17 12:12:20 2015
// Last Modified By : Peter A. Buhr
// Last Modified On : Tue May 19 16:49:04 2015
// Update Count     : 3
//

#include "ResolveTypeof.h"

#include <cassert>               // for assert

#include "AST/CVQualifiers.hpp"
#include "AST/Node.hpp"
#include "AST/Pass.hpp"
#include "AST/Type.hpp"
#include "AST/TypeEnvironment.hpp"
#include "Common/PassVisitor.h"  // for PassVisitor
#include "Common/utility.h"      // for copy
#include "Resolver.h"            // for resolveInVoidContext
#include "SynTree/Expression.h"  // for Expression
#include "SynTree/Mutator.h"     // for Mutator
#include "SynTree/Type.h"        // for TypeofType, Type
#include "SymTab/Mangler.h"
#include "InitTweak/InitTweak.h" // for isConstExpr

namespace SymTab {
class Indexer;
}  // namespace SymTab

namespace ResolvExpr {
        namespace {
#if 0
                void
                printAlts( const AltList &list, std::ostream &os, int indent = 0 )
                {
                        for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
                                i->print( os, indent );
                                os << std::endl;
                        }
                }
#endif
        }

        class ResolveTypeof_old : public WithShortCircuiting {
          public:
                ResolveTypeof_old( const SymTab::Indexer &indexer ) : indexer( indexer ) {}
                void premutate( TypeofType *typeofType );
                Type * postmutate( TypeofType *typeofType );

          private:
                const SymTab::Indexer &indexer;
        };

        Type * resolveTypeof( Type *type, const SymTab::Indexer &indexer ) {
                PassVisitor<ResolveTypeof_old> mutator( indexer );
                return type->acceptMutator( mutator );
        }

        void ResolveTypeof_old::premutate( TypeofType * ) {
                visit_children = false;
        }

        Type * ResolveTypeof_old::postmutate( TypeofType *typeofType ) {
#if 0
                std::cerr << "resolving typeof: ";
                typeofType->print( std::cerr );
                std::cerr << std::endl;
#endif
                // pass on null expression
                if ( ! typeofType->expr ) return typeofType;

                bool isBasetypeof = typeofType->is_basetypeof;
                auto oldQuals = typeofType->get_qualifiers().val;

                Type* newType;
                if ( TypeExpr* tyExpr = dynamic_cast<TypeExpr*>(typeofType->expr) ) {
                        // typeof wrapping type
                        newType = tyExpr->type;
                        tyExpr->type = nullptr;
                        delete tyExpr;
                } else {
                        // typeof wrapping expression
                        Expression * newExpr = resolveInVoidContext( typeofType->expr, indexer );
                        assert( newExpr->result && ! newExpr->result->isVoid() );
                        newType = newExpr->result;
                        newExpr->result = nullptr;
                        delete typeofType;
                        delete newExpr;
                }

                // clear qualifiers for base, combine with typeoftype quals in any case
                if ( isBasetypeof ) {
                        // replace basetypeof(<enum>) by int
                        if ( dynamic_cast<EnumInstType*>(newType) ) {
                                Type* newerType =
                                        new BasicType{ newType->get_qualifiers(), BasicType::SignedInt,
                                        newType->attributes };
                                delete newType;
                                newType = newerType;
                        }
                        newType->get_qualifiers().val
                                = ( newType->get_qualifiers().val & ~Type::Qualifiers::Mask ) | oldQuals;
                } else {
                        newType->get_qualifiers().val |= oldQuals;
                }

                return newType;
        }

namespace {
        struct ResolveTypeof_new : public ast::WithShortCircuiting {
                const ast::SymbolTable & localSymtab;

                ResolveTypeof_new( const ast::SymbolTable & syms ) : localSymtab( syms ) {}

                void previsit( const ast::TypeofType * ) { visit_children = false; }

                const ast::Type * postvisit( const ast::TypeofType * typeofType ) {
                        // pass on null expression
                        if ( ! typeofType->expr ) return typeofType;

                        ast::ptr< ast::Type > newType;
                        if ( auto tyExpr = typeofType->expr.as< ast::TypeExpr >() ) {
                                // typeof wrapping type
                                newType = tyExpr->type;
                        } else {
                                // typeof wrapping expression
                                ast::TypeEnvironment dummy;
                                ast::ptr< ast::Expr > newExpr =
                                        resolveInVoidContext( typeofType->expr, localSymtab, dummy );
                                assert( newExpr->result && ! newExpr->result->isVoid() );
                                newType = newExpr->result;
                        }

                        // clear qualifiers for base, combine with typeoftype quals regardless
                        if ( typeofType->kind == ast::TypeofType::Basetypeof ) {
                                // replace basetypeof(<enum>) by int
                                if ( newType.as< ast::EnumInstType >() ) {
                                        newType = new ast::BasicType{
                                                ast::BasicType::SignedInt, newType->qualifiers, copy(newType->attributes) };
                                }
                                reset_qualifiers(
                                        newType,
                                        ( newType->qualifiers & ~ast::CV::EquivQualifiers ) | typeofType->qualifiers );
                        } else {
                                add_qualifiers( newType, typeofType->qualifiers );
                        }

                        return newType.release();
                }
        };
} // anonymous namespace

const ast::Type * resolveTypeof( const ast::Type * type , const ast::SymbolTable & symtab ) {
        ast::Pass< ResolveTypeof_new > mutator{ symtab };
        return type->accept( mutator );
}

struct FixArrayDimension {
        // should not require a mutable symbol table - prevent pass template instantiation
        const ast::SymbolTable & _symtab; 
        FixArrayDimension(const ast::SymbolTable & symtab): _symtab(symtab) {}

        const ast::ArrayType * previsit (const ast::ArrayType * arrayType) {
                if (!arrayType->dimension) return arrayType;
                auto mutType = mutate(arrayType);
                ast::ptr<ast::Type> sizetype = ast::sizeType ? ast::sizeType : new ast::BasicType(ast::BasicType::LongUnsignedInt); 
                mutType->dimension = findSingleExpression(arrayType->dimension, sizetype, _symtab);

                if (InitTweak::isConstExpr(mutType->dimension)) {
                        mutType->isVarLen = ast::LengthFlag::FixedLen;
                }
                else {
                        mutType->isVarLen = ast::LengthFlag::VariableLen;
                }
                return mutType;
        }
};

const ast::Type * fixArrayType( const ast::Type * type, const ast::SymbolTable & symtab) {
        ast::Pass<FixArrayDimension> visitor {symtab};
        return type->accept(visitor);
}

const ast::ObjectDecl * fixObjectType( const ast::ObjectDecl * decl , const ast::SymbolTable & symtab ) {
        if (!decl->isTypeFixed) { 
                auto mutDecl = mutate(decl);
                auto resolvedType = resolveTypeof(decl->type, symtab);
                resolvedType = fixArrayType(resolvedType, symtab);
                mutDecl->type = resolvedType;

                // check variable length if object is an array.
                // xxx - should this be part of fixObjectType?

                /*
                if (auto arrayType = dynamic_cast<const ast::ArrayType *>(resolvedType)) {
                        auto dimExpr = findSingleExpression(arrayType->dimension, ast::sizeType, symtab);
                        if (auto varexpr = arrayType->dimension.as<ast::VariableExpr>()) {// hoisted previously
                                if (InitTweak::isConstExpr(varexpr->var.strict_as<ast::ObjectDecl>()->init)) {
                                        auto mutType = mutate(arrayType);
                                        mutType->isVarLen = ast::LengthFlag::VariableLen;
                                        mutDecl->type = mutType;
                                }
                        }
                }
                */


                if (!mutDecl->name.empty()) 
                        mutDecl->mangleName = Mangle::mangle(mutDecl); // do not mangle unnamed variables
                
                mutDecl->isTypeFixed = true;
                return mutDecl;
        }
        return decl;
}

} // namespace ResolvExpr

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