Esempio n. 1
0
void c_qualifierst::read(const typet &src)
{
  if(src.get_bool(ID_C_constant))
    is_constant=true;

  if(src.get_bool(ID_C_volatile))
    is_volatile=true;

  if(src.get_bool(ID_C_restricted))
    is_restricted=true;

  if(src.get_bool(ID_C_atomic))
    is_atomic=true;

  if(src.get_bool(ID_C_ptr32))
    is_ptr32=true;

  if(src.get_bool(ID_C_ptr64))
    is_ptr64=true;

  if(src.get_bool(ID_C_transparent_union))
    is_transparent_union=true;

  if(src.get_bool(ID_C_noreturn))
    is_noreturn=true;
}
Esempio n. 2
0
bool is_global_const(const irep_idt &name, const typet &type)
{
  if (!type.get_bool(ID_C_constant)) return false;
  const std::string &n=id2string(name);
  if (std::string::npos != n.find(CEGIS_CONSTANT_PREFIX)) return true;
  return std::string::npos == n.find(NS_SEP);
}
void c_qualifierst::read(const typet &src)
{
  if(src.get_bool(ID_C_constant))
    is_constant=true;

  if(src.get_bool(ID_C_volatile))
    is_volatile=true;

  if(src.get_bool(ID_C_restricted))
    is_restricted=true;

  if(src.get_bool(ID_C_ptr32))
    is_ptr32=true;

  if(src.get_bool(ID_C_ptr64))
    is_ptr64=true;
}
Esempio n. 4
0
void c_typecheck_baset::typecheck_symbol_type(typet &type)
{
  {
    // add prefix
    symbol_typet &symbol_type=to_symbol_type(type);
    symbol_type.set_identifier(add_language_prefix(symbol_type.get_identifier()));
  }

  // adjust identifier, if needed
  replace_symbol(type);

  const irep_idt &identifier=
    to_symbol_type(type).get_identifier();

  symbol_tablet::symbolst::const_iterator s_it=
    symbol_table.symbols.find(identifier);

  if(s_it==symbol_table.symbols.end())
  {
    err_location(type);
    str << "type symbol `" << identifier << "' not found";
    throw 0;
  }

  const symbolt &symbol=s_it->second;

  if(!symbol.is_type)
  {
    err_location(type);
    throw "expected type symbol";
  }
  
  if(symbol.is_macro)
  {
    // overwrite, but preserve (add) any qualifiers and other flags

    c_qualifierst c_qualifiers(type);
    bool is_packed=type.get_bool(ID_C_packed);
    irept alignment=type.find(ID_C_alignment);
    
    c_qualifiers+=c_qualifierst(symbol.type);
    type=symbol.type;
    c_qualifiers.write(type);
    
    if(is_packed) type.set(ID_C_packed, true);
    if(alignment.is_not_nil()) type.set(ID_C_alignment, alignment);
  }
    
  // CPROVER extensions
  if(symbol.base_name=="__CPROVER_rational")
  {
    type=rational_typet();
  }
  else if(symbol.base_name=="__CPROVER_integer")
  {
    type=integer_typet();
  }
}
Esempio n. 5
0
void c_typecheck_baset::typecheck_type(typet &type)
{
  // we first convert, and then check
  
  // do we have alignment?
  if(type.find(ID_C_alignment).is_not_nil())
  {
    exprt &alignment=static_cast<exprt &>(type.add(ID_C_alignment));
    if(alignment.id()!=ID_default)
    {
      typecheck_expr(alignment);
      make_constant(alignment);
    }
  }

  if(type.id()==ID_code)
    typecheck_code_type(to_code_type(type));
  else if(type.id()==ID_array)
    typecheck_array_type(to_array_type(type));
  else if(type.id()==ID_pointer)
    typecheck_type(type.subtype());
  else if(type.id()==ID_struct ||
          type.id()==ID_union)
    typecheck_compound_type(to_struct_union_type(type));
  else if(type.id()==ID_c_enum)
  {
  }
  else if(type.id()==ID_c_bitfield)
    typecheck_c_bit_field_type(type);
  else if(type.id()==ID_typeof)
    typecheck_typeof_type(type);
  else if(type.id()==ID_symbol)
    typecheck_symbol_type(type);
  else if(type.id()==ID_vector)
    typecheck_vector_type(to_vector_type(type));
  else if(type.id()==ID_custom_unsignedbv ||
          type.id()==ID_custom_signedbv ||
          type.id()==ID_custom_floatbv ||
          type.id()==ID_custom_fixedbv)
    typecheck_custom_type(type);

  // do a bit of rule checking

  if(type.get_bool(ID_C_restricted) &&
     type.id()!=ID_pointer &&
     type.id()!=ID_array)
  {
    err_location(type);
    error("only a pointer can be 'restrict'");
    throw 0;
  }
  
}
Esempio n. 6
0
void cpp_typecheckt::typecheck_type(typet &type)
{
  assert(!type.id().empty());
  assert(type.is_not_nil());

  try
  {
    cpp_convert_plain_type(type);
  }

  catch(const char *err)
  {
    error().source_location=type.source_location();
    error() << err << eom;
    throw 0;
  }

  catch(const std::string &err)
  {
    error().source_location=type.source_location();
    error() << err << eom;
    throw 0;
  }

  if(type.id()==ID_cpp_name)
  {
    c_qualifierst qualifiers(type);

    cpp_namet cpp_name;
    cpp_name.swap(type);

    exprt symbol_expr=resolve(
      cpp_name,
      cpp_typecheck_resolvet::wantt::TYPE,
      cpp_typecheck_fargst());

    if(symbol_expr.id()!=ID_type)
    {
      error().source_location=type.source_location();
      error() << "error: expected type" << eom;
      throw 0;
    }

    type=symbol_expr.type();
    assert(type.is_not_nil());

    if(type.get_bool(ID_C_constant))
      qualifiers.is_constant = true;

    qualifiers.write(type);
  }
  else if(type.id()==ID_struct ||
          type.id()==ID_union)
  {
    typecheck_compound_type(to_struct_union_type(type));
  }
  else if(type.id()==ID_pointer)
  {
    // the pointer might have a qualifier, but do subtype first
    typecheck_type(type.subtype());

    // Check if it is a pointer-to-member
    if(type.find("to-member").is_not_nil())
    {
      // these can point either to data members or member functions
      // of a class

      typet &class_object=static_cast<typet &>(type.add("to-member"));

      if(class_object.id()==ID_cpp_name)
      {
        assert(class_object.get_sub().back().id()=="::");
        class_object.get_sub().pop_back();
      }

      typecheck_type(class_object);

      // there may be parameters if this is a pointer to member function
      if(type.subtype().id()==ID_code)
      {
        irept::subt &parameters=type.subtype().add(ID_parameters).get_sub();

        if(parameters.empty() ||
           parameters.front().get(ID_C_base_name)!=ID_this)
        {
          // Add 'this' to the parameters
          exprt a0(ID_parameter);
          a0.set(ID_C_base_name, ID_this);
          a0.type().id(ID_pointer);
          a0.type().subtype() = class_object;
          parameters.insert(parameters.begin(), a0);
        }
      }
    }
  }
  else if(type.id()==ID_array)
  {
    exprt &size_expr=to_array_type(type).size();

    if(size_expr.is_not_nil())
    {
      typecheck_expr(size_expr);
      simplify(size_expr, *this);
    }

    typecheck_type(type.subtype());

    if(type.subtype().get_bool(ID_C_constant))
      type.set(ID_C_constant, true);

    if(type.subtype().get_bool(ID_C_volatile))
      type.set(ID_C_volatile, true);
  }
  else if(type.id()==ID_code)
  {
    code_typet &code_type=to_code_type(type);
    typecheck_type(code_type.return_type());

    code_typet::parameterst &parameters=code_type.parameters();

    for(auto &param : parameters)
    {
      typecheck_type(param.type());

      // see if there is a default value
      if(param.has_default_value())
      {
        typecheck_expr(param.default_value());
        implicit_typecast(param.default_value(), param.type());
      }
    }
  }
  else if(type.id()==ID_template)
  {
    typecheck_type(type.subtype());
  }
  else if(type.id()==ID_c_enum)
  {
    typecheck_enum_type(type);
  }
  else if(type.id()==ID_c_enum_tag)
  {
  }
  else if(type.id()==ID_c_bit_field)
  {
    typecheck_c_bit_field_type(to_c_bit_field_type(type));
  }
  else if(type.id()==ID_unsignedbv ||
          type.id()==ID_signedbv ||
          type.id()==ID_bool ||
          type.id()==ID_floatbv ||
          type.id()==ID_fixedbv ||
          type.id()==ID_empty)
  {
  }
  else if(type.id()==ID_symbol)
  {
  }
  else if(type.id()==ID_constructor ||
          type.id()==ID_destructor)
  {
  }
  else if(type.id()=="cpp-cast-operator")
  {
  }
  else if(type.id()=="cpp-template-type")
  {
  }
  else if(type.id()==ID_typeof)
  {
    exprt e=static_cast<const exprt &>(type.find(ID_expr_arg));

    if(e.is_nil())
    {
      typet tmp_type=
        static_cast<const typet &>(type.find(ID_type_arg));

      if(tmp_type.id()==ID_cpp_name)
      {
        // this may be ambiguous -- it can be either a type or
        // an expression

        cpp_typecheck_fargst fargs;

        exprt symbol_expr=resolve(
          to_cpp_name(static_cast<const irept &>(tmp_type)),
          cpp_typecheck_resolvet::wantt::BOTH,
          fargs);

        type=symbol_expr.type();
      }
      else
      {
        typecheck_type(tmp_type);
        type=tmp_type;
      }
    }
    else
    {
      typecheck_expr(e);
      type=e.type();
    }
  }
  else if(type.id()==ID_decltype)
  {
    exprt e=static_cast<const exprt &>(type.find(ID_expr_arg));
    typecheck_expr(e);
    type=e.type();
  }
  else if(type.id()==ID_unassigned)
  {
    // ignore, for template parameter guessing
  }
  else if(type.id()==ID_template_class_instance)
  {
    // ok (internally generated)
  }
  else if(type.id()==ID_block_pointer)
  {
    // This is an Apple extension for lambda-like constructs.
    // http://thirdcog.eu/pwcblocks/
  }
  else if(type.id()==ID_nullptr)
  {
  }
  else
  {
    error().source_location=type.source_location();
    error() << "unexpected cpp type: " << type.pretty() << eom;
    throw 0;
  }

  assert(type.is_not_nil());
}
Esempio n. 7
0
bool is_rvalue_reference(const typet &type)
{
  return type.id()==ID_pointer &&
         type.get_bool(ID_C_rvalue_reference);
}
Esempio n. 8
0
std::string type2name(const typet &type)
{
  std::string result;
  
  // qualifiers first
  if(type.get_bool(ID_C_constant))
    result+="c";

  if(type.get_bool(ID_C_restricted))
    result+="r";

  if(type.get_bool(ID_C_volatile))
    result+="v";

  if(type.id()==irep_idt())
    throw "Empty type encountered.";
  else if(type.id()==ID_empty)
    result+="V";   
  else if(type.id()==ID_signedbv)
    result+="S" + type.get_string(ID_width);
  else if(type.id()==ID_unsignedbv)
    result+="U" + type.get_string(ID_width);
  else if(type.id()==ID_bool) 
    result+="B";
  else if(type.id()==ID_integer) 
    result+="I";
  else if(type.id()==ID_real) 
    result+="R";
  else if(type.id()==ID_complex) 
    result+="C";
  else if(type.id()==ID_floatbv) 
    result+="F" + type.get_string(ID_width);
  else if(type.id()==ID_fixedbv) 
    result+="X" + type.get_string(ID_width);
  else if(type.id()==ID_natural)
    result+="N";
  else if(type.id()==ID_pointer)
    result+="*";
  else if(type.id()==ID_reference)
    result+="&";
  else if(type.id()==ID_code)
  {
    const code_typet &t=to_code_type(type);
    const code_typet::argumentst arguments=t.arguments();
    result+="P(";

    for(code_typet::argumentst::const_iterator it=arguments.begin();
        it!=arguments.end();
        it++)
    {      
      result+=type2name(it->type());
      result+="'" + id2string(it->get_identifier()) + "'|";
    }
    result.resize(result.size()-1);
    result+=")";
  }
  else if(type.id()==ID_array)
  {
    const array_typet &t=to_array_type(type);
    if(t.size().is_nil())
      result+="ARR?";
    else
      result+="ARR"+t.size().get_string(ID_value);
  }
  else if(type.id()==ID_symbol)
  {
    result+="SYM#"+type.get_string(ID_identifier)+"#";
  }
  else if(type.id()==ID_struct || 
          type.id()==ID_union)
  {
    if(type.id()==ID_struct) result+="ST";
    if(type.id()==ID_union) result+="UN";
    const struct_union_typet &t=to_struct_union_type(type);
    const struct_union_typet::componentst &components = t.components();
    result+="[";
    for(struct_union_typet::componentst::const_iterator
        it=components.begin();
        it!=components.end();
        it++)
    {            
      if(it!=components.begin()) result+="|";
      result+=type2name(it->type());
      result+="'"+it->get_string(ID_name)+"'|";
    }
    result+="]";
  }
  else if(type.id()==ID_incomplete_struct)
    result +="ST?";
  else if(type.id()==ID_incomplete_union)
    result +="UN?";
  else if(type.id()==ID_c_enum)
    result +="EN"+type.get_string(ID_width);
  else if(type.id()==ID_incomplete_c_enum)
    result +="EN?";
  else if(type.id()==ID_c_bitfield)
    result+="BF"+type.get_string(ID_size);
  else if(type.id()==ID_vector)
    result+="VEC"+type.get_string(ID_size);
  else
    throw (std::string("Unknown type '") + 
           type.id_string() + 
           "' encountered."); 
    
  if(type.has_subtype())
  {
    result+="{";
    result+=type2name(type.subtype());    
    result+="}";
  }

  if(type.has_subtypes())
  {
    result+="$";
    forall_subtypes(it, type)
    {      
      result+=type2name(*it);
      result+="|";      
    }
Esempio n. 9
0
exprt c_sizeoft::sizeof_rec(const typet &type)
{
  exprt dest;

  if(type.id()==ID_signedbv ||
     type.id()==ID_unsignedbv ||
     type.id()==ID_floatbv ||
     type.id()==ID_fixedbv ||
     type.id()==ID_c_enum ||
     type.id()==ID_incomplete_c_enum)
  {
    // We round up to bytes.
    // See special treatment for bit-fields below.
    unsigned bits=type.get_int(ID_width);
    unsigned bytes=bits/8;
    if((bits%8)!=0) bytes++;
    dest=from_integer(bytes, size_type());
  }
  else if(type.id()==ID_pointer)
  {
    // the following is an MS extension
    if(type.get_bool(ID_C_ptr32))
      return from_integer(4, size_type());
             
    unsigned bits=config.ansi_c.pointer_width;
    unsigned bytes=bits/8;
    if((bits%8)!=0) bytes++;
    dest=from_integer(bytes, size_type());
  }
  else if(type.id()==ID_bool)
  {
    // We fit booleans into a byte.
    dest=from_integer(1, size_type());
  }
  else if(type.id()==ID_array)
  {
    const exprt &size_expr=
      to_array_type(type).size();
      
    if(size_expr.is_nil())
    {
      // treated like an empty array
      dest=from_integer(0, size_type());
    }
    else
    {
      exprt tmp_dest=sizeof_rec(type.subtype());

      if(tmp_dest.is_nil())
        return tmp_dest;

      mp_integer a, b;

      if(!to_integer(tmp_dest, a) &&
         !to_integer(size_expr, b))
      {
        dest=from_integer(a*b, size_type());
      }
      else
      {
        dest.id(ID_mult);
        dest.type()=size_type();
        dest.copy_to_operands(size_expr);
        dest.move_to_operands(tmp_dest);
        c_implicit_typecast(dest.op0(), dest.type(), ns);
        c_implicit_typecast(dest.op1(), dest.type(), ns);
      }
    }
  }
  else if(type.id()==ID_struct)
  {
    const struct_typet::componentst &components=
      to_struct_type(type).components();

    dest=from_integer(0, size_type());
    
    mp_integer bit_field_width=0;

    for(struct_typet::componentst::const_iterator
        it=components.begin();
        it!=components.end();
        it++)
    {
      const typet &sub_type=ns.follow(it->type());

      if(it->get_bool(ID_is_type))
      {
      }
      else if(sub_type.id()==ID_code)
      {
      }
      else if(it->get_is_bit_field())
      {
        // this needs to be a signedbv/unsignedbv/enum
        if(sub_type.id()!=ID_signedbv &&
           sub_type.id()!=ID_unsignedbv &&
           sub_type.id()!=ID_c_enum)
          return nil_exprt();
          
        // We just sum them up.
        // This assumes they are properly padded.
        bit_field_width+=sub_type.get_int(ID_width);
      }
      else
      {
        exprt tmp=sizeof_rec(sub_type);

        if(tmp.is_nil())
          return tmp;

        dest=plus_exprt(dest, tmp);
      }
    }
    
    if(bit_field_width!=0)
      dest=plus_exprt(dest, from_integer(bit_field_width/8, size_type()));
  }
  else if(type.id()==ID_union)
  {
    const irept::subt &components=
      type.find(ID_components).get_sub();

    mp_integer max_size=0;

    forall_irep(it, components)
    {
      if(it->get_bool(ID_is_type))
        continue;

      const typet &sub_type=static_cast<const typet &>(it->find(ID_type));

      if(sub_type.id()==ID_code)
      {
      }
      else
      {
        exprt tmp=sizeof_rec(sub_type);

        if(tmp.is_nil())
          return tmp;
          
        simplify(tmp, ns);

        mp_integer tmp_int;

        if(to_integer(tmp, tmp_int))
          return static_cast<const exprt &>(get_nil_irep());

        if(tmp_int>max_size) max_size=tmp_int;
      }
    }

    dest=from_integer(max_size, size_type());
  }
  else if(type.id()==ID_symbol)
Esempio n. 10
0
void c_typecastt::implicit_typecast_followed(
  exprt &expr,
  const typet &src_type,
  const typet &dest_type)
{
  if(dest_type.id()==ID_union)

  // do transparent union
  if(dest_type.id()==ID_union &&
     dest_type.get_bool(ID_C_transparent_union) &&
     src_type.id()!=ID_union)
  {
    // The argument corresponding to a transparent union type can be of any
    // type in the union; no explicit cast is required.
    
    // Check union members.
    const union_typet &dest_union_type=to_union_type(dest_type);

    for(union_typet::componentst::const_iterator
        it=dest_union_type.components().begin();
        it!=dest_union_type.components().end();
        it++)
    {
      if(!check_c_implicit_typecast(src_type, it->type()))
      {
        // build union constructor
        exprt union_expr(ID_union, dest_union_type);
        union_expr.move_to_operands(expr);
        union_expr.set(ID_component_name, it->get_name());
        expr=union_expr;
        return; // ok
      }
    }
  }

  if(dest_type.id()==ID_pointer)
  {
    // special case: 0 == NULL

    if(expr.is_zero() && (
       src_type.id()==ID_unsignedbv ||
       src_type.id()==ID_signedbv ||
       src_type.id()==ID_natural ||
       src_type.id()==ID_integer))
    {
      expr=exprt(ID_constant, dest_type);
      expr.set(ID_value, ID_NULL);
      return; // ok
    }
  
    if(src_type.id()==ID_pointer ||
       src_type.id()==ID_array)
    {
      // we are quite generous about pointers
      
      const typet &src_sub=ns.follow(src_type.subtype());
      const typet &dest_sub=ns.follow(dest_type.subtype());

      if(is_void_pointer(src_type) ||
         is_void_pointer(dest_type))
      {
        // from/to void is always good
      }
      else if(src_sub.id()==ID_code &&
              dest_sub.id()==ID_code)
      {
        // very generous:
        // between any two function pointers it's ok
      }
      else if(base_type_eq(src_type.subtype(), dest_type.subtype(), ns))
      {
        // ok
      }
      else if((is_number(src_sub) || src_sub.id()==ID_c_enum) &&
              (is_number(dest_sub) || dest_sub.id()==ID_c_enum))
      {
        // Also generous: between any to scalar types it's ok.
        // We should probably check the size.
      }
      else
        warnings.push_back("incompatible pointer types");

      // check qualifiers

      /*
      if(src_type.subtype().get_bool(ID_C_constant) &&
         !dest_type.subtype().get_bool(ID_C_constant))
        warnings.push_back("disregarding const");
      */

      if(src_type.subtype().get_bool(ID_C_volatile) &&
         !dest_type.subtype().get_bool(ID_C_volatile))
        warnings.push_back("disregarding volatile");

      if(src_type==dest_type)
      {
        expr.type()=src_type; // because of qualifiers
      }
      else
        do_typecast(expr, dest_type);

      return; // ok
    }
  }
  
  if(check_c_implicit_typecast(src_type, dest_type))
    errors.push_back("implicit conversion not permitted");
  else if(src_type!=dest_type)
    do_typecast(expr, dest_type);
}
Esempio n. 11
0
void c_typecheck_baset::typecheck_type(typet &type)
{
  // we first convert, and then check
  {
    ansi_c_convert_typet ansi_c_convert_type(get_message_handler());

    ansi_c_convert_type.read(type);
    ansi_c_convert_type.write(type);
  }

  if(type.id()==ID_already_typechecked)
  {
    // need to preserve any qualifiers
    c_qualifierst c_qualifiers(type);
    c_qualifiers+=c_qualifierst(type.subtype());
    bool packed=type.get_bool(ID_C_packed);
    exprt alignment=static_cast<const exprt &>(type.find(ID_C_alignment));
    irept _typedef=type.find(ID_C_typedef);

    type=type.subtype();

    c_qualifiers.write(type);
    if(packed)
      type.set(ID_C_packed, true);
    if(alignment.is_not_nil())
      type.add(ID_C_alignment, alignment);
    if(_typedef.is_not_nil())
      type.add(ID_C_typedef, _typedef);

    return; // done
  }

  // do we have alignment?
  if(type.find(ID_C_alignment).is_not_nil())
  {
    exprt &alignment=static_cast<exprt &>(type.add(ID_C_alignment));
    if(alignment.id()!=ID_default)
    {
      typecheck_expr(alignment);
      make_constant(alignment);
    }
  }

  if(type.id()==ID_code)
    typecheck_code_type(to_code_type(type));
  else if(type.id()==ID_array)
    typecheck_array_type(to_array_type(type));
  else if(type.id()==ID_pointer)
    typecheck_type(type.subtype());
  else if(type.id()==ID_struct ||
          type.id()==ID_union)
    typecheck_compound_type(to_struct_union_type(type));
  else if(type.id()==ID_c_enum)
    typecheck_c_enum_type(type);
  else if(type.id()==ID_c_enum_tag)
    typecheck_c_enum_tag_type(to_c_enum_tag_type(type));
  else if(type.id()==ID_c_bit_field)
    typecheck_c_bit_field_type(to_c_bit_field_type(type));
  else if(type.id()==ID_typeof)
    typecheck_typeof_type(type);
  else if(type.id()==ID_symbol)
    typecheck_symbol_type(type);
  else if(type.id()==ID_vector)
    typecheck_vector_type(to_vector_type(type));
  else if(type.id()==ID_custom_unsignedbv ||
          type.id()==ID_custom_signedbv ||
          type.id()==ID_custom_floatbv ||
          type.id()==ID_custom_fixedbv)
    typecheck_custom_type(type);
  else if(type.id()==ID_gcc_attribute_mode)
  {
    // get that mode
    irep_idt mode=type.get(ID_size);

    // A list of all modes ist at
    // http://www.delorie.com/gnu/docs/gcc/gccint_53.html
    typecheck_type(type.subtype());

    typet underlying_type=type.subtype();

    // gcc allows this, but clang doesn't; it's a compiler hint only,
    // but we'll try to interpret it the GCC way
    if(underlying_type.id()==ID_c_enum_tag)
    {
      underlying_type=
        follow_tag(to_c_enum_tag_type(underlying_type)).subtype();

      assert(underlying_type.id()==ID_signedbv ||
             underlying_type.id()==ID_unsignedbv);
    }

    if(underlying_type.id()==ID_signedbv ||
       underlying_type.id()==ID_unsignedbv)
    {
      bool is_signed=underlying_type.id()==ID_signedbv;

      typet result;

      if(mode=="__QI__") // 8 bits
        result=is_signed?signed_char_type():unsigned_char_type();
      else if(mode=="__byte__") // 8 bits
        result=is_signed?signed_char_type():unsigned_char_type();
      else if(mode=="__HI__") // 16 bits
        result=is_signed?signed_short_int_type():unsigned_short_int_type();
      else if(mode=="__SI__") // 32 bits
        result=is_signed?signed_int_type():unsigned_int_type();
      else if(mode=="__word__") // long int, we think
        result=is_signed?signed_long_int_type():unsigned_long_int_type();
      else if(mode=="__pointer__") // we think this is size_t/ssize_t
        result=is_signed?signed_size_type():size_type();
      else if(mode=="__DI__") // 64 bits
      {
        if(config.ansi_c.long_int_width==64)
          result=is_signed?signed_long_int_type():unsigned_long_int_type();
        else
        {
          assert(config.ansi_c.long_long_int_width==64);
          result=
            is_signed?signed_long_long_int_type():unsigned_long_long_int_type();
        }
      }
      else if(mode=="__TI__") // 128 bits
        result=is_signed?gcc_signed_int128_type():gcc_unsigned_int128_type();
      else if(mode=="__V2SI__") // vector of 2 ints, deprecated by gcc
        result=
          vector_typet(
            is_signed?signed_int_type():unsigned_int_type(),
            from_integer(2, size_type()));
      else if(mode=="__V4SI__") // vector of 4 ints, deprecated by gcc
        result=
          vector_typet(
            is_signed?signed_int_type():unsigned_int_type(),
            from_integer(4, size_type()));
      else // give up, just use subtype
        result=type.subtype();

      // save the location
      result.add_source_location()=type.source_location();

      if(type.subtype().id()==ID_c_enum_tag)
      {
        const irep_idt &tag_name=
          to_c_enum_tag_type(type.subtype()).get_identifier();

        symbol_tablet::symbolst::iterator entry=
          symbol_table.symbols.find(tag_name);
        assert(entry!=symbol_table.symbols.end());

        entry->second.type.subtype()=result;
      }

      type=result;
    }
    else if(underlying_type.id()==ID_floatbv)
    {
      typet result;

      if(mode=="__SF__") // 32 bits
        result=float_type();
      else if(mode=="__DF__") // 64 bits
        result=double_type();
      else if(mode=="__TF__") // 128 bits
        result=gcc_float128_type();
      else if(mode=="__V2SF__") // vector of 2 floats, deprecated by gcc
        result=vector_typet(float_type(), from_integer(2, size_type()));
      else if(mode=="__V2DF__") // vector of 2 doubles, deprecated by gcc
        result=vector_typet(double_type(), from_integer(2, size_type()));
      else if(mode=="__V4SF__") // vector of 4 floats, deprecated by gcc
        result=vector_typet(float_type(), from_integer(4, size_type()));
      else if(mode=="__V4DF__") // vector of 4 doubles, deprecated by gcc
        result=vector_typet(double_type(), from_integer(4, size_type()));
      else // give up, just use subtype
        result=type.subtype();

      // save the location
      result.add_source_location()=type.source_location();

      type=result;
    }
    else if(underlying_type.id()==ID_complex)
    {
      // gcc allows this, but clang doesn't -- see enums above
      typet result;

      if(mode=="__SC__") // 32 bits
        result=float_type();
      else if(mode=="__DC__") // 64 bits
        result=double_type();
      else if(mode=="__TC__") // 128 bits
        result=gcc_float128_type();
      else // give up, just use subtype
        result=type.subtype();

      // save the location
      result.add_source_location()=type.source_location();

      type=complex_typet(result);
    }
    else
    {
      error().source_location=type.source_location();
      error() << "attribute mode `" << mode
              << "' applied to inappropriate type `"
              << to_string(type) << "'" << eom;
      throw 0;
    }
  }

  // do a mild bit of rule checking

  if(type.get_bool(ID_C_restricted) &&
     type.id()!=ID_pointer &&
     type.id()!=ID_array)
  {
    error().source_location=type.source_location();
    error() << "only a pointer can be 'restrict'" << eom;
    throw 0;
  }
}
Esempio n. 12
0
void c_typecheck_baset::typecheck_c_enum_type(typet &type)
{
  // These come with the declarations
  // of the enum constants as operands.

  exprt &as_expr=static_cast<exprt &>(static_cast<irept &>(type));
  source_locationt source_location=type.source_location();

  // We allow empty enums in the grammar to get better
  // error messages.
  if(as_expr.operands().empty())
  {
    error().source_location=source_location;
    error() << "empty enum" << eom;
    throw 0;
  }

  // enums start at zero;
  // we also track min and max to find a nice base type
  mp_integer value=0, min_value=0, max_value=0;

  std::list<c_enum_typet::c_enum_membert> enum_members;

  // We need to determine a width, and a signedness
  // to obtain an 'underlying type'.
  // We just do int, but gcc might pick smaller widths
  // if the type is marked as 'packed'.
  // gcc/clang may also pick a larger width. Visual Studio doesn't.

  for(auto &op : as_expr.operands())
  {
    ansi_c_declarationt &declaration=to_ansi_c_declaration(op);
    exprt &v=declaration.declarator().value();

    if(v.is_not_nil()) // value given?
    {
      exprt tmp_v=v;
      typecheck_expr(tmp_v);
      add_rounding_mode(tmp_v);
      simplify(tmp_v, *this);
      if(tmp_v.is_true())
        value=1;
      else if(tmp_v.is_false())
        value=0;
      else if(!to_integer(tmp_v, value))
      {
      }
      else
      {
        error().source_location=v.source_location();
        error() << "enum is not a constant";
        throw 0;
      }
    }

    if(value<min_value)
      min_value=value;
    if(value>max_value)
      max_value=value;

    typet constant_type=
      enum_constant_type(min_value, max_value);

    v=from_integer(value, constant_type);

    declaration.type()=constant_type;
    typecheck_declaration(declaration);

    irep_idt base_name=
      declaration.declarator().get_base_name();

    irep_idt identifier=
      declaration.declarator().get_name();

    // store
    c_enum_typet::c_enum_membert member;
    member.set_identifier(identifier);
    member.set_base_name(base_name);
    member.set_value(integer2string(value));
    enum_members.push_back(member);

    // produce value for next constant
    ++value;
  }

  // Remove these now; we add them to the
  // c_enum symbol later.
  as_expr.operands().clear();

  bool is_packed=type.get_bool(ID_C_packed);

  // tag?
  if(type.find(ID_tag).is_nil())
  {
    // None, it's anonymous. We generate a tag.
    std::string anon_identifier="#anon_enum";

    for(const auto &member : enum_members)
    {
      anon_identifier+='$';
      anon_identifier+=id2string(member.get_base_name());
      anon_identifier+='=';
      anon_identifier+=id2string(member.get_value());
    }

    if(is_packed)
      anon_identifier+="#packed";

    type.add(ID_tag).set(ID_identifier, anon_identifier);
  }

  irept &tag=type.add(ID_tag);
  irep_idt base_name=tag.get(ID_C_base_name);
  irep_idt identifier=tag.get(ID_identifier);

  // Put into symbol table
  symbolt enum_tag_symbol;

  enum_tag_symbol.is_type=true;
  enum_tag_symbol.type=type;
  enum_tag_symbol.location=source_location;
  enum_tag_symbol.is_file_local=true;
  enum_tag_symbol.base_name=base_name;
  enum_tag_symbol.name=identifier;

  // throw in the enum members as 'body'
  irept::subt &body=enum_tag_symbol.type.add(ID_body).get_sub();

  for(const auto &member : enum_members)
    body.push_back(member);

  // We use a subtype to store the underlying type.
  typet underlying_type=
    enum_underlying_type(min_value, max_value, is_packed);

  enum_tag_symbol.type.subtype()=underlying_type;

  // is it in the symbol table already?
  symbol_tablet::symbolst::iterator s_it=
    symbol_table.symbols.find(identifier);

  if(s_it!=symbol_table.symbols.end())
  {
    // Yes.
    symbolt &symbol=s_it->second;

    if(symbol.type.id()==ID_incomplete_c_enum)
    {
      // Ok, overwrite the type in the symbol table.
      // This gives us the members and the subtype.
      symbol.type=enum_tag_symbol.type;
    }
    else if(symbol.type.id()==ID_c_enum)
    {
      // We might already have the same anonymous enum, and this is
      // simply ok. Note that the C standard treats these as
      // different types.
      if(!base_name.empty())
      {
        error().source_location=type.source_location();
        error() << "redeclaration of enum tag" << eom;
        throw 0;
      }
    }
    else
    {
      error().source_location=source_location;
      error() << "use of tag that does not match previous declaration" << eom;
      throw 0;
    }
  }
  else
  {
    symbolt *new_symbol;
    move_symbol(enum_tag_symbol, new_symbol);
  }

  // We produce a c_enum_tag as the resulting type.
  type.id(ID_c_enum_tag);
  type.remove(ID_tag);
  type.set(ID_identifier, identifier);
}