Пример #1
0
void cpp_typecheckt::convert_non_template_declaration(
  cpp_declarationt &declaration)
{
  assert(!declaration.is_template());

  // we first check if this is a typedef
  typet &declaration_type=declaration.type();
  bool is_typedef=declaration.is_typedef();

  declaration.name_anon_struct_union();
  typecheck_type(declaration_type);
  
  // Elaborate any class template instance _unless_ we do a typedef.
  // These are only elaborated on usage!
  if(!is_typedef)
    elaborate_class_template(declaration_type);
  
  // Special treatment for anonymous unions
  if(declaration.declarators().empty() &&
     follow(declaration.type()).get_bool(ID_C_is_anonymous))
  {
    typet final_type=follow(declaration.type());

    if(final_type.id()!=ID_union)
    {
      error().source_location=final_type.source_location();
      error() << "top-level declaration does not declare anything"
              << eom;
      throw 0;
    }

    codet dummy;
    convert_anonymous_union(declaration, dummy);
  }

  // do the declarators (optional)
  Forall_cpp_declarators(it, declaration)
  {
    // copy the declarator (we destroy the original)
    cpp_declaratort declarator=*it;

    cpp_declarator_convertert cpp_declarator_converter(*this);

    cpp_declarator_converter.is_typedef=is_typedef;

    symbolt &symbol=cpp_declarator_converter.convert(
      declaration_type, declaration.storage_spec(),
      declaration.member_spec(), declarator);

    // any template instance to remember?
    if(declaration.find(ID_C_template).is_not_nil())
    {
      symbol.type.set(ID_C_template, declaration.find(ID_C_template));
      symbol.type.set(ID_C_template_arguments, declaration.find(ID_C_template_arguments));
    }

    // replace declarator by symbol expression
    exprt tmp=cpp_symbol_expr(symbol);
    it->swap(tmp);

    // is there a constructor to be called for the declarator?
    if(symbol.is_lvalue &&
       declarator.init_args().has_operands())
    {
      symbol.value=
        cpp_constructor(
          symbol.location,
          cpp_symbol_expr(symbol),
          declarator.init_args().operands());
    }
  }
void cpp_typecheckt::typecheck_friend_declaration(
  symbolt &symbol,
  cpp_declarationt &declaration)
{
  // A friend of a class can be a function/method,
  // or a struct/class/union type.

  if(declaration.is_template())
  {
    return; // TODO
    err_location(declaration.type().location());
    str << "friend template not supported";
    throw 0;
  }
  
  // we distinguish these whether there is a declarator
  if(declaration.declarators().empty())
  {
    typet &ftype=declaration.type();

    // must be struct or union
    if(ftype.id()!=ID_struct && ftype.id()!=ID_union)
    {
      err_location(declaration.type());
      str << "unexpected friend";
      throw 0;
    }
       
    if(ftype.find(ID_body).is_not_nil())
    {
      err_location(declaration.type());
      str << "friend declaration must not have compound body";
      throw 0;
    }

    // typecheck ftype
    
    // TODO
//    typecheck_type(ftype);
//    assert(ftype.id()==ID_symbol);
//    symbol.type.add("#friends").move_to_sub(ftype);

    return;
  }

  // It should be a friend function.
  // Do the declarators.
  
  Forall_cpp_declarators(sub_it, declaration)
  {
    bool has_value = sub_it->value().is_not_nil();

    if(!has_value)
    {
      // If no value is found, then we jump to the
      // global scope, and we convert the declarator
      // as if it were declared there
      cpp_save_scopet saved_scope(cpp_scopes);
      cpp_scopes.go_to_global_scope();
      cpp_declarator_convertert cpp_declarator_converter(*this);
      const symbolt &conv_symb = cpp_declarator_converter.convert(
          declaration.type(), declaration.storage_spec(),
          declaration.member_spec(), *sub_it);
      exprt symb_expr = cpp_symbol_expr(conv_symb);
      symbol.type.add("#friends").move_to_sub(symb_expr);
    }
    else
    {
      cpp_declarator_convertert cpp_declarator_converter(*this);
      cpp_declarator_converter.is_friend = true;

      declaration.member_spec().set_inline(true);

      const symbolt &conv_symb = cpp_declarator_converter.convert(
        declaration.type(), declaration.storage_spec(),
        declaration.member_spec(), *sub_it);

      exprt symb_expr = cpp_symbol_expr(conv_symb);

      symbol.type.add("#friends").move_to_sub(symb_expr);
    }
  }
Пример #3
0
void cpp_typecheckt::convert_template_declaration(
  cpp_declarationt &declaration)
{
  assert(declaration.is_template());

  if(declaration.member_spec().is_virtual())
  {
    err_location(declaration);
    str <<  "invalid use of 'virtual' in template declaration";
    throw 0;
  }

  if(declaration.is_typedef())
  {
    err_location(declaration);
    str << "template declaration for typedef";
    throw 0;
  }

  typet &type=declaration.type();

  // there are
  // 1) function templates
  // 2) class templates
  // 3) template members of class templates (static or methods)
  // 4) variable templates (C++14)

  if(declaration.is_class_template())
  {
    // there should not be declarators
    if(!declaration.declarators().empty())
    {
      err_location(declaration);
      throw "class template not expected to have declarators";
    }

    // it needs to be a class template
    if(type.id()!=ID_struct)
    {
      err_location(declaration);
      throw "expected class template";
    }

    // Is it class template specialization?
    // We can tell if there are template arguments in the class name,
    // like template<...> class tag<stuff> ...
    if((static_cast<const cpp_namet &>(
       type.find(ID_tag))).has_template_args())
    {
      convert_class_template_specialization(declaration);
      return;
    }

    typecheck_class_template(declaration);
    return;
  }
  else // maybe function template, maybe class template member, maye template variable
  {
    // there should be declarators in either case
    if(declaration.declarators().empty())
    {
      err_location(declaration);
      throw "non-class template is expected to have a declarator";
    }

    // Is it function template specialization?
    // Only full specialization is allowed!
    if(declaration.template_type().template_parameters().empty())
    {
      convert_template_function_or_member_specialization(declaration);
      return;
    }

    // Explicit qualification is forbidden for function templates,
    // which we can use to distinguish them.

    assert(declaration.declarators().size()>=1);

    cpp_declaratort &declarator=declaration.declarators()[0];
    const cpp_namet &cpp_name=to_cpp_name(declarator.add(ID_name));

    if(cpp_name.is_qualified() ||
       cpp_name.has_template_args())
      return typecheck_class_template_member(declaration);

    // must be function template  
    typecheck_function_template(declaration);
    return;
  }
}
void cpp_typecheckt::typecheck_compound_declarator(
  const symbolt &symbol,
  const cpp_declarationt &declaration,
  cpp_declaratort &declarator,
  struct_typet::componentst &components,
  const irep_idt &access,
  bool is_static,
  bool is_typedef,
  bool is_mutable)
{
  bool is_cast_operator=
    declaration.type().id()=="cpp-cast-operator";

  if(is_cast_operator)
  {
    assert(declarator.name().get_sub().size()==2 &&
           declarator.name().get_sub().front().id()==ID_operator);

    typet type=static_cast<typet &>(declarator.name().get_sub()[1]);
    declarator.type().subtype()=type;

    irept name(ID_name);
    name.set(ID_identifier, "("+cpp_type2name(type)+")");
    declarator.name().get_sub().back().swap(name);
  }

  typet final_type=
    declarator.merge_type(declaration.type());

  // this triggers template elaboration
  elaborate_class_template(final_type);

  typecheck_type(final_type);
  
  cpp_namet cpp_name;
  cpp_name.swap(declarator.name());
  
  irep_idt base_name;
  
  if(cpp_name.is_nil())
  {
    // Yes, there can be members without name.
    base_name=irep_idt();
  }
  else if(cpp_name.is_simple_name())
  {
    base_name=cpp_name.get_base_name();
  }
  else
  {
    err_location(cpp_name.location());
    str << "declarator in compound needs to be simple name";
    throw 0;
  }


  bool is_method=!is_typedef && final_type.id()==ID_code;
  bool is_constructor=declaration.is_constructor();
  bool is_destructor=declaration.is_destructor();
  bool is_virtual=declaration.member_spec().is_virtual();
  bool is_explicit=declaration.member_spec().is_explicit();
  bool is_inline=declaration.member_spec().is_inline();

  final_type.set(ID_C_member_name, symbol.name);

  // first do some sanity checks

  if(is_virtual && !is_method)
  {
    err_location(cpp_name.location());
    str << "only methods can be virtual";
    throw 0;
  }

  if(is_inline && !is_method)
  {
    err_location(cpp_name.location());
    str << "only methods can be inlined";
    throw 0;
  }

  if(is_virtual && is_static)
  {
    err_location(cpp_name.location());
    str << "static methods cannot be virtual";
    throw 0;
  }

  if(is_cast_operator && is_static)
  {
    err_location(cpp_name.location());
    str << "cast operators cannot be static`";
    throw 0;
  }

  if(is_constructor && is_virtual)
  {
    err_location(cpp_name.location());
    str << "constructors cannot be virtual";
    throw 0;
  }

  if(!is_constructor && is_explicit)
  {
    err_location(cpp_name.location());
    str << "only constructors can be explicit";
    throw 0;
  }

  if(is_constructor &&
     base_name!=id2string(symbol.base_name))
  {
    err_location(cpp_name.location());
    str << "member function must return a value or void";
    throw 0;
  }

  if(is_destructor &&
     base_name!="~"+id2string(symbol.base_name))
  {
    err_location(cpp_name.location());
    str << "destructor with wrong name";
    throw 0;
  }

  // now do actual work

  struct_typet::componentt component;

  irep_idt identifier=
    language_prefix+
    cpp_scopes.current_scope().prefix+
    id2string(base_name);

  component.set(ID_name, identifier);
  component.type()=final_type;
  component.set(ID_access, access);
  component.set(ID_base_name, base_name);
  component.set(ID_pretty_name, base_name);
  component.location()=cpp_name.location();

  if(cpp_name.is_operator())
  {
    component.set("is_operator", true);
    component.type().set("#is_operator", true);
  }

  if(is_cast_operator)
    component.set("is_cast_operator", true);

  if(declaration.member_spec().is_explicit())
    component.set("is_explicit", true);

  typet &method_qualifier=
    (typet &)declarator.add("method_qualifier");

  if(is_static)
  {
    component.set(ID_is_static, true);
    component.type().set("#is_static", true);
  }

  if(is_typedef)
    component.set("is_type", true);

  if(is_mutable)
    component.set("is_mutable", true);

  exprt &value=declarator.value();
  irept &initializers=declarator.member_initializers();

  if(is_method)
  {
    component.set(ID_is_inline, declaration.member_spec().is_inline());

    // the 'virtual' name of the function
    std::string virtual_name=
    component.get_string(ID_base_name)+
      id2string(
        function_identifier(static_cast<const typet &>(component.find(ID_type))));

    if(method_qualifier.id()==ID_const)
      virtual_name += "$const";

    if(component.type().get(ID_return_type) == ID_destructor)
      virtual_name= "@dtor";
    
    // The method may be virtual implicitly.
    std::set<irep_idt> virtual_bases;

    for(struct_typet::componentst::const_iterator
        it=components.begin();
        it!=components.end();
        it++)
    {
      if(it->get_bool("is_virtual"))
      {
        if(it->get("virtual_name")==virtual_name)
        {
          is_virtual=true;
          const code_typet& code_type = to_code_type(it->type());
          assert(code_type.arguments().size()>0);
          const typet& pointer_type = code_type.arguments()[0].type();
          assert(pointer_type.id() == ID_pointer);
          virtual_bases.insert(pointer_type.subtype().get(ID_identifier));
        }
      }
    }

    if(!is_virtual)
    {
      typecheck_member_function(
        symbol.name, component, initializers,
        method_qualifier, value);

      if(!value.is_nil() && !is_static)
      {
        err_location(cpp_name.location());
        str << "no initialization allowed here";
        throw 0;
      }
    }
    else // virtual
    {
      component.type().set("#is_virtual", true);
      component.type().set("#virtual_name",virtual_name);

      // Check if it is a pure virtual method
      if(is_virtual)
      {
        if(value.is_not_nil() && value.id() == ID_constant)
        {
          mp_integer i;
          to_integer(value, i);
          if(i!=0)
          {
            err_location(declarator.name().location());
            str << "expected 0 to mark pure virtual method, got " << i;
          }
          component.set("is_pure_virtual", true);
          value.make_nil();
        }
      }

      typecheck_member_function(
        symbol.name,
        component,
        initializers,
        method_qualifier,
        value);

      // get the virtual-table symbol type
      irep_idt vt_name = "virtual_table::"+symbol.name.as_string();

      contextt::symbolst::iterator vtit =
        context.symbols.find(vt_name);

      if(vtit == context.symbols.end())
      {
        // first time: create a virtual-table symbol type 
        symbolt vt_symb_type;
        vt_symb_type.name= vt_name;
        vt_symb_type.base_name="virtual_table::"+symbol.base_name.as_string();
        vt_symb_type.pretty_name = vt_symb_type.base_name;
        vt_symb_type.mode=ID_cpp;
        vt_symb_type.module=module;
        vt_symb_type.location=symbol.location;
        vt_symb_type.type = struct_typet();
        vt_symb_type.type.set(ID_name, vt_symb_type.name);
        vt_symb_type.is_type = true;

        bool failed = context.move(vt_symb_type);
        assert(!failed);
        vtit = context.symbols.find(vt_name);

        // add a virtual-table pointer 
        struct_typet::componentt compo;
        compo.type() = pointer_typet(symbol_typet(vt_name));
        compo.set_name(symbol.name.as_string() +"::@vtable_pointer");
        compo.set(ID_base_name, "@vtable_pointer");
        compo.set(ID_pretty_name, symbol.base_name.as_string() +"@vtable_pointer");
        compo.set("is_vtptr", true);
        compo.set(ID_access, ID_public);
        components.push_back(compo);
        put_compound_into_scope(compo);
      }
      
      assert(vtit->second.type.id()==ID_struct);

      struct_typet &virtual_table=
        to_struct_type(vtit->second.type);

      component.set("virtual_name", virtual_name);
      component.set("is_virtual", is_virtual);

      // add an entry to the virtual table
      struct_typet::componentt vt_entry;
      vt_entry.type() = pointer_typet(component.type());
      vt_entry.set_name(vtit->first.as_string()+"::"+virtual_name);
      vt_entry.set(ID_base_name, virtual_name);
      vt_entry.set(ID_pretty_name, virtual_name);
      vt_entry.set(ID_access, ID_public);
      vt_entry.location() = symbol.location;
      virtual_table.components().push_back(vt_entry);

      // take care of overloading
      while(!virtual_bases.empty())
      {
        irep_idt virtual_base = *virtual_bases.begin();

        // a new function that does 'late casting' of the 'this' parameter
        symbolt func_symb;
        func_symb.name=component.get_name().as_string() + "::" +virtual_base.as_string();
        func_symb.base_name=component.get(ID_base_name);
        func_symb.pretty_name = component.get(ID_base_name);
        func_symb.mode=ID_cpp;
        func_symb.module=module;
        func_symb.location=component.location();
        func_symb.type=component.type();

        // change the type of the 'this' pointer
        code_typet& code_type = to_code_type(func_symb.type);
        code_typet::argumentt& arg= code_type.arguments().front();
        arg.type().subtype().set(ID_identifier, virtual_base);

        // create symbols for the arguments
        code_typet::argumentst& args =  code_type.arguments();
        for(unsigned i=0; i<args.size(); i++)
        {
          code_typet::argumentt& arg = args[i];
          irep_idt base_name = arg.get_base_name();

          if(base_name==irep_idt())
            base_name="arg"+i2string(i);

          symbolt arg_symb;
          arg_symb.name = func_symb.name.as_string() + "::"+ base_name.as_string();
          arg_symb.base_name = base_name;
          arg_symb.pretty_name = base_name;
          arg_symb.mode=ID_cpp;
          arg_symb.location=func_symb.location;
          arg_symb.type = arg.type();

          arg.set(ID_C_identifier, arg_symb.name);

          // add the argument to the symbol table
          bool failed = context.move(arg_symb);
          assert(!failed);
        }

        // do the body of the function
        typecast_exprt late_cast(to_code_type(component.type()).arguments()[0].type());

        late_cast.op0()=
          symbol_expr(namespacet(context).lookup(
            args[0].get(ID_C_identifier)));
        
        if(code_type.return_type().id()!=ID_empty &&
           code_type.return_type().id()!=ID_destructor)
        {
          side_effect_expr_function_callt expr_call;
          expr_call.function() = symbol_exprt(component.get_name(),component.type());
          expr_call.type() = to_code_type(component.type()).return_type();
          expr_call.arguments().reserve(args.size());
          expr_call.arguments().push_back(late_cast);

          for(unsigned i=1; i < args.size(); i++)
          {
            expr_call.arguments().push_back(
              symbol_expr(namespacet(context).lookup(
                args[i].get(ID_C_identifier))));
          }

          code_returnt code_return;
          code_return.return_value() = expr_call;

          func_symb.value = code_return;
        }
        else
        {
          code_function_callt code_func;
          code_func.function() = symbol_exprt(component.get_name(),component.type());
          code_func.arguments().reserve(args.size());
          code_func.arguments().push_back(late_cast);

          for(unsigned i=1; i < args.size(); i++)
          {
            code_func.arguments().push_back(
              symbol_expr(namespacet(context).lookup(
                args[i].get(ID_C_identifier))));
          }

          func_symb.value = code_func;
        }

        // add this new function to the list of components
        
        struct_typet::componentt new_compo = component;
        new_compo.type() = func_symb.type;
        new_compo.set_name(func_symb.name);
        components.push_back(new_compo);

        // add the function to the symbol table
        {
          bool failed = context.move(func_symb);
          assert(!failed);
        }

        // next base
        virtual_bases.erase(virtual_bases.begin());
      }
    }
  }
  
  if(is_static && !is_method) // static non-method member
  {
    // add as global variable to context
    symbolt static_symbol;
    static_symbol.mode=symbol.mode;
    static_symbol.name=identifier;
    static_symbol.type=component.type();
    static_symbol.base_name=component.get(ID_base_name);
    static_symbol.lvalue=true;
    static_symbol.static_lifetime=true;
    static_symbol.location=cpp_name.location();
    static_symbol.is_extern=true;
    
    // TODO: not sure about this: should be defined separately!
    dynamic_initializations.push_back(static_symbol.name);

    symbolt *new_symbol;
    if(context.move(static_symbol, new_symbol))
    {
      err_location(cpp_name.location());
	str << "redeclaration of static member `" 
	    << static_symbol.base_name.as_string()
	    << "'";
      throw 0;
    }

    if(value.is_not_nil())
    {
      if(cpp_is_pod(new_symbol->type))
      {
        new_symbol->value.swap(value);
        c_typecheck_baset::do_initializer(*new_symbol);

        // these are macros if they are PODs and come with a (constant) value
        if(new_symbol->type.get_bool(ID_C_constant))
        {
          simplify(new_symbol->value, *this);
          new_symbol->is_macro=true;
        }
      }
      else
      {
        symbol_exprt symexpr;
        symexpr.set_identifier(new_symbol->name);

        exprt::operandst ops;
        ops.push_back(value);
        codet defcode =
          cpp_constructor(locationt(), symexpr, ops);

        new_symbol->value.swap(defcode);
      }
    }
  }

  // array members must have fixed size
  check_fixed_size_array(component.type());

  put_compound_into_scope(component);

  components.push_back(component);
}