C++ (Cpp) type_mapt Example

Introduction

The c++ (cpp) type_mapt example is extracted from the most popular open source projects, you can refer to the following example for usage.

Programming language: C++ (Cpp)

Class/type: type_mapt

Example#1

void remove_function_pointerst::remove_function_pointer(
  goto_programt &goto_program,
  goto_programt::targett target)
{
  const code_function_callt &code=
    to_code_function_call(target->code);

  const exprt &function=code.function();
  
  // this better have the right type
  const code_typet &call_type=to_code_type(function.type());
  
  assert(function.id()==ID_dereference);
  assert(function.operands().size()==1);

  const exprt &pointer=function.op0();
  
  typedef std::list<exprt> functionst;
  functionst functions;
  
  // get all type-compatible functions
  // whose address is ever taken
  for(type_mapt::const_iterator f_it=
      type_map.begin();
      f_it!=type_map.end();
      f_it++)
  {
    // address taken?
    if(address_taken.find(f_it->first)==address_taken.end())
      continue;

    // type-compatible?
    if(!is_type_compatible(call_type, f_it->second))
      continue;
    
    symbol_exprt expr;
    expr.type()=f_it->second;
    expr.set_identifier(f_it->first);
    functions.push_back(expr);
  }
  
  // the final target is a skip
  goto_programt final_skip;

  goto_programt::targett t_final=final_skip.add_instruction();
  t_final->make_skip();
  
  // build the calls and gotos

  goto_programt new_code_calls;
  goto_programt new_code_gotos;

  for(functionst::const_iterator
      it=functions.begin();
      it!=functions.end();
      it++)
  {
    // call function
    goto_programt::targett t1=new_code_calls.add_instruction();
    t1->make_function_call(code);
    to_code_function_call(t1->code).function()=*it;
    
    // the signature of the function might not match precisely
    fix_argument_types(to_code_function_call(t1->code));
    
    fix_return_type(to_code_function_call(t1->code), new_code_calls);
    // goto final
    goto_programt::targett t3=new_code_calls.add_instruction();
    t3->make_goto(t_final, true_exprt());
  
    // goto to call
    address_of_exprt address_of;
    address_of.object()=*it;
    address_of.type()=pointer_typet();
    address_of.type().subtype()=it->type();
    
    if(address_of.type()!=pointer.type())
      address_of.make_typecast(pointer.type());
    
    goto_programt::targett t4=new_code_gotos.add_instruction();
    t4->make_goto(t1, equal_exprt(pointer, address_of));
  }

  // fall-through
  if(add_safety_assertion)
  {
    goto_programt::targett t=new_code_gotos.add_instruction();
    t->make_assertion(false_exprt());
    t->location.set(ID_property, "pointer dereference");
    t->location.set(ID_comment, "invalid function pointer");
  }
  
  goto_programt new_code;
  
  // patch them all together
  new_code.destructive_append(new_code_gotos);
  new_code.destructive_append(new_code_calls);
  new_code.destructive_append(final_skip);
  
  // set locations
  Forall_goto_program_instructions(it, new_code)
  {
    irep_idt property=it->location.get_property();
    irep_idt comment=it->location.get_comment();
    it->location=target->location;
    it->function=target->function;
    if(!property.empty()) it->location.set_property(property);
    if(!comment.empty()) it->location.set_comment(comment);
  }

Example#2

File: remove_function_pointers.cppProject: diffblue/cbmc

void remove_function_pointerst::remove_function_pointer(
  goto_programt &goto_program,
  goto_programt::targett target)
{
  const code_function_callt &code=
    to_code_function_call(target->code);

  const exprt &function=code.function();

  // this better have the right type
  code_typet call_type=to_code_type(function.type());

  // refine the type in case the forward declaration was incomplete
  if(call_type.has_ellipsis() &&
     call_type.parameters().empty())
  {
    call_type.remove_ellipsis();
    forall_expr(it, code.arguments())
      call_type.parameters().push_back(
        code_typet::parametert(it->type()));
  }

  assert(function.id()==ID_dereference);
  assert(function.operands().size()==1);

  const exprt &pointer=function.op0();

  // Is this simple?
  if(pointer.id()==ID_address_of &&
     to_address_of_expr(pointer).object().id()==ID_symbol)
  {
    to_code_function_call(target->code).function()=
      to_address_of_expr(pointer).object();
    return;
  }

  typedef std::list<exprt> functionst;
  functionst functions;

  bool return_value_used=code.lhs().is_not_nil();

  // get all type-compatible functions
  // whose address is ever taken
  for(type_mapt::const_iterator f_it=
      type_map.begin();
      f_it!=type_map.end();
      f_it++)
  {
    // address taken?
    if(address_taken.find(f_it->first)==address_taken.end())
      continue;

    // type-compatible?
    if(!is_type_compatible(return_value_used, call_type, f_it->second))
      continue;

    if(f_it->first=="pthread_mutex_cleanup")
      continue;

    symbol_exprt expr;
    expr.type()=f_it->second;
    expr.set_identifier(f_it->first);
    functions.push_back(expr);
  }

  // the final target is a skip
  goto_programt final_skip;

  goto_programt::targett t_final=final_skip.add_instruction();
  t_final->make_skip();

  // build the calls and gotos

  goto_programt new_code_calls;
  goto_programt new_code_gotos;

  for(functionst::const_iterator
      it=functions.begin();
      it!=functions.end();
      it++)
  {
    // call function
    goto_programt::targett t1=new_code_calls.add_instruction();
    t1->make_function_call(code);
    to_code_function_call(t1->code).function()=*it;

    // the signature of the function might not match precisely
    fix_argument_types(to_code_function_call(t1->code));

    fix_return_type(to_code_function_call(t1->code), new_code_calls);
    // goto final
    goto_programt::targett t3=new_code_calls.add_instruction();
    t3->make_goto(t_final, true_exprt());

    // goto to call
    address_of_exprt address_of;
    address_of.object()=*it;
    address_of.type()=pointer_typet();
    address_of.type().subtype()=it->type();

    if(address_of.type()!=pointer.type())
      address_of.make_typecast(pointer.type());

    goto_programt::targett t4=new_code_gotos.add_instruction();
    t4->make_goto(t1, equal_exprt(pointer, address_of));
  }

  // fall-through
  if(add_safety_assertion)
  {
    goto_programt::targett t=new_code_gotos.add_instruction();
    t->make_assertion(false_exprt());
    t->source_location.set_property_class("pointer dereference");
    t->source_location.set_comment("invalid function pointer");
  }

  goto_programt new_code;

  // patch them all together
  new_code.destructive_append(new_code_gotos);
  new_code.destructive_append(new_code_calls);
  new_code.destructive_append(final_skip);

  // set locations
  Forall_goto_program_instructions(it, new_code)
  {
    irep_idt property_class=it->source_location.get_property_class();
    irep_idt comment=it->source_location.get_comment();
    it->source_location=target->source_location;
    it->function=target->function;
    if(!property_class.empty()) it->source_location.set_property_class(property_class);
    if(!comment.empty()) it->source_location.set_comment(comment);
  }