Example #1
0
void invariant_propagationt::add_objects(
  const goto_programt &goto_program)
{
  // get the globals
  object_listt globals;
  get_globals(globals);
  
  // get the locals
  goto_programt::decl_identifierst locals;
  goto_program.get_decl_identifiers(locals);

  // cache the list for the locals to speed things up  
  typedef hash_map_cont<irep_idt, object_listt, irep_id_hash> object_cachet;
  object_cachet object_cache;

  for(goto_programt::instructionst::const_iterator
      i_it=goto_program.instructions.begin();
      i_it!=goto_program.instructions.end();
      i_it++)
  {
    #if 0
    invariant_sett &is=(*this)[i_it].invariant_set;
    
    is.add_objects(globals);
    #endif

    for(goto_programt::decl_identifierst::const_iterator
        l_it=locals.begin();
        l_it!=locals.end();
        l_it++)
    {
      // cache hit?
      object_cachet::const_iterator e_it=object_cache.find(*l_it);

      if(e_it==object_cache.end())
      {
        const symbolt &symbol=ns.lookup(*l_it);
        
        object_listt &objects=object_cache[*l_it];
        get_objects(symbol, objects);
        #if 0
        is.add_objects(objects);
        #endif
      }
      #if 0
      else
        is.add_objects(e_it->second);
      #endif
    }
  }
}    
void string_instrumentationt::do_function_call(
  goto_programt &dest,
  goto_programt::targett target)
{
  code_function_callt &call=
    to_code_function_call(target->code);
  exprt &function=call.function();
  //const exprt &lhs=call.lhs();
  
  if(function.id()==ID_symbol)
  {
    const irep_idt &identifier=
      to_symbol_expr(function).get_identifier();

    if(identifier=="strcoll")
    {
    }
    else if(identifier=="strncmp")
      do_strncmp(dest, target, call);
    else if(identifier=="strxfrm")
    {
    }
    else if(identifier=="strchr")
      do_strchr(dest, target, call);
    else if(identifier=="strcspn")
    {
    }
    else if(identifier=="strpbrk")
    {
    }
    else if(identifier=="strrchr")
      do_strrchr(dest, target, call);
    else if(identifier=="strspn")
    {
    }
    else if(identifier=="strerror")
      do_strerror(dest, target, call);
    else if(identifier=="strstr")
      do_strstr(dest, target, call);
    else if(identifier=="strtok")
      do_strtok(dest, target, call);
    else if(identifier=="sprintf")
      do_sprintf(dest, target, call);
    else if(identifier=="snprintf")
      do_snprintf(dest, target, call);
    else if(identifier=="fscanf")
      do_fscanf(dest, target, call);
    
    dest.update();
  }
}
Example #3
0
void stack_depth(
  goto_programt &goto_program,
  const symbol_exprt &symbol,
  const int i_depth,
  const exprt &max_depth)
{
  assert(!goto_program.instructions.empty());

  goto_programt::targett first=goto_program.instructions.begin();

  binary_relation_exprt guard(symbol, ID_le, max_depth);
  goto_programt::targett assert_ins=goto_program.insert_before(first);
  assert_ins->make_assertion(guard);
  assert_ins->location=first->location;
  assert_ins->function=first->function;

  assert_ins->location.set_comment("Stack depth exceeds "+i2string(i_depth));
  assert_ins->location.set_property("stack-depth");

  goto_programt::targett plus_ins=goto_program.insert_before(first);
  plus_ins->make_assignment();
  plus_ins->code=code_assignt(symbol,
      plus_exprt(symbol, from_integer(1, symbol.type())));
  plus_ins->location=first->location;
  plus_ins->function=first->function;

  goto_programt::targett last=--goto_program.instructions.end();
  assert(last->is_end_function());

  goto_programt::instructiont minus_ins;
  minus_ins.make_assignment();
  minus_ins.code=code_assignt(symbol,
      minus_exprt(symbol, from_integer(1, symbol.type())));
  minus_ins.location=last->location;
  minus_ins.function=last->function;

  goto_program.insert_before_swap(last, minus_ins);
}
Example #4
0
void remove_return(goto_programt &body, const goto_programt::targett pos)
{
  code_function_callt &call=to_code_function_call(pos->code);
  const irep_idt &id=to_symbol_expr(call.function()).get_identifier();
  const typet &type=call.lhs().type();
  const source_locationt &loc=pos->source_location;
  const irep_idt &func=pos->function;
  const goto_programt::targett assign=body.insert_after(pos);
  assign->make_assignment();
  assign->source_location=loc;
  assign->code=code_assignt(call.lhs(), get_ret_val_var(id, type));
  assign->function=func;
  call.lhs().make_nil();
}
void goto_convertt::convert_CPROVER_throw(
  const codet &code,
  goto_programt &dest)
{
  // set the 'exception' flag
  {
    goto_programt::targett t_set_exception=
      dest.add_instruction(ASSIGN);

    t_set_exception->source_location=code.source_location();
    t_set_exception->code=code_assignt(exception_flag(), true_exprt());
  }

  // do we catch locally?
  if(targets.throw_set)
  {
    // need to process destructor stack
    unwind_destructor_stack(
      code.source_location(), targets.throw_stack_size, dest);

    // add goto
    goto_programt::targett t=dest.add_instruction();
    t->make_goto(targets.throw_target);
    t->source_location=code.source_location();
  }
  else // otherwise, we do a return
  {
    // need to process destructor stack
    unwind_destructor_stack(code.source_location(), 0, dest);

    // add goto
    goto_programt::targett t=dest.add_instruction();
    t->make_goto(targets.return_target);
    t->source_location=code.source_location();
  }
}
Example #6
0
void goto_checkt::add_guarded_claim(
  const exprt &_expr,
  const std::string &comment,
  const std::string &property_class,
  const source_locationt &source_location,
  const exprt &src_expr,
  const guardt &guard)
{
  exprt expr(_expr);

  // first try simplifier on it
  if(enable_simplify)
    simplify(expr, ns);

  // throw away trivial properties?
  if(!retain_trivial && expr.is_true())
    return;

  // add the guard
  exprt guard_expr=guard.as_expr();

  exprt new_expr;

  if(guard_expr.is_true())
    new_expr.swap(expr);
  else
  {
    new_expr=exprt(ID_implies, bool_typet());
    new_expr.move_to_operands(guard_expr, expr);
  }

  if(assertions.insert(new_expr).second)
  {
    goto_program_instruction_typet type=
      enable_assert_to_assume?ASSUME:ASSERT;

    goto_programt::targett t=new_code.add_instruction(type);

    std::string source_expr_string=from_expr(ns, "", src_expr);

    t->guard.swap(new_expr);
    t->source_location=source_location;
    t->source_location.set_comment(comment+" in "+source_expr_string);
    t->source_location.set_property_class(property_class);
  }
}
void goto_convertt::do_function_call_other(
  const exprt &lhs,
  const exprt &function,
  const exprt::operandst &arguments,
  goto_programt &dest)
{
  // don't know what to do with it
  goto_programt::targett t=dest.add_instruction(FUNCTION_CALL);

  code_function_callt function_call;
  function_call.add_source_location()=function.source_location();
  function_call.lhs()=lhs;
  function_call.function()=function;
  function_call.arguments()=arguments;

  t->source_location=function.source_location();
  t->code.swap(function_call);
}
Example #8
0
void goto_convertt::convert_try_catch(
  const codet &code,
  goto_programt &dest)
{
  assert(code.operands().size()>=2);
  
  // add the CATCH-push instruction to 'dest'
  goto_programt::targett catch_push_instruction=dest.add_instruction();
  catch_push_instruction->make_catch();
  catch_push_instruction->code.set_statement(ID_catch);
  catch_push_instruction->source_location=code.source_location();
  
  // the CATCH-push instruction is annotated with a list of IDs,
  // one per target
  irept::subt &exception_list=
    catch_push_instruction->code.add(ID_exception_list).get_sub();

  // add a SKIP target for the end of everything
  goto_programt end;
  goto_programt::targett end_target=end.add_instruction();
  end_target->make_skip();
  
  // the first operand is the 'try' block
  convert(to_code(code.op0()), dest);
  
  // add the CATCH-pop to the end of the 'try' block
  goto_programt::targett catch_pop_instruction=dest.add_instruction();
  catch_pop_instruction->make_catch();
  catch_pop_instruction->code.set_statement(ID_catch);
  
  // add a goto to the end of the 'try' block
  dest.add_instruction()->make_goto(end_target);

  for(unsigned i=1; i<code.operands().size(); i++)
  {
    const codet &block=to_code(code.operands()[i]);
  
    // grab the ID and add to CATCH instruction
    exception_list.push_back(irept(block.get(ID_exception_id)));
    
    goto_programt tmp;
    convert(block, tmp);
    catch_push_instruction->targets.push_back(tmp.instructions.begin());
    dest.destructive_append(tmp);

    // add a goto to the end of the 'catch' block
    dest.add_instruction()->make_goto(end_target);
  }

  // add the end-target  
  dest.destructive_append(end);
}
Example #9
0
void goto_checkt::add_guarded_claim(const exprt &_expr,
    const std::string &comment, const std::string &property,
    const locationt &location, const guardt &guard)
{
  bool all_claims = options.get_bool_option("all-claims");
  exprt expr(_expr);

  // first try simplifier on it
  if (!options.get_bool_option("no-simplify"))
  {
    expr2tc tmpexpr;
    migrate_expr(expr, tmpexpr);
    base_type(tmpexpr, ns);
    expr = migrate_expr_back(tmpexpr);
    simplify(expr);
  }

  if (!all_claims && expr.is_true())
    return;

  // add the guard
  exprt guard_expr = migrate_expr_back(guard.as_expr());

  exprt new_expr;

  if (guard_expr.is_true())
    new_expr.swap(expr);
  else
  {
    new_expr = exprt("=>", bool_typet());
    new_expr.move_to_operands(guard_expr, expr);
  }

  if (assertions.insert(new_expr).second)
  {
    goto_programt::targett t = new_code.add_instruction(ASSERT);
    migrate_expr(new_expr, t->guard);

    t->location = location;
    t->location.comment(comment);
    t->location.property(property);
  }
}
Example #10
0
void cfg_dominatorst::construct_cfg(
  const goto_programt &program, 
  goto_programt::const_targett PC)
{
  nodet &node=node_map[PC];
  node.PC=PC;
  
  program.get_successors(PC, node.successors);

  // now do backward edges
  for(goto_programt::const_targetst::const_iterator
        s_it=node.successors.begin();
      s_it!=node.successors.end();
      s_it++)
  {
    node_map[*s_it].predecessors.push_back(node.PC);
  }

}
Example #11
0
void string_instrumentationt::do_snprintf(
  goto_programt &dest,
  goto_programt::targett target,
  code_function_callt &call)
{
  const code_function_callt::argumentst &arguments=call.arguments();

  if(arguments.size()<3)
  {
    error().source_location=target->source_location;
    error() << "snprintf expected to have three or more arguments"
            << eom;
    throw 0;
  }

  goto_programt tmp;

  goto_programt::targett assertion=tmp.add_instruction();
  assertion->source_location=target->source_location;
  assertion->source_location.set_property_class("string");
  assertion->source_location.set_comment("snprintf buffer overflow");

  exprt bufsize=buffer_size(arguments[0]);
  assertion->make_assertion(
    binary_relation_exprt(bufsize, ID_ge, arguments[1]));

  do_format_string_read(tmp, target, arguments, 2, 3, "snprintf");

  if(call.lhs().is_not_nil())
  {
    goto_programt::targett return_assignment=tmp.add_instruction(ASSIGN);
    return_assignment->source_location=target->source_location;

    exprt rhs=side_effect_expr_nondett(call.lhs().type());
    rhs.add_source_location()=target->source_location;

    return_assignment->code=code_assignt(call.lhs(), rhs);
  }

  target->make_skip();
  dest.insert_before_swap(target, tmp);
}
Example #12
0
void havoc_loopst::build_havoc_code(
  const goto_programt::targett loop_head,
  const modifiest &modifies,
  goto_programt &dest)
{
  for(modifiest::const_iterator
      m_it=modifies.begin();
      m_it!=modifies.end();
      m_it++)
  {
    exprt lhs=*m_it;
    exprt rhs=side_effect_expr_nondett(lhs.type());

    goto_programt::targett t=dest.add_instruction(ASSIGN);
    t->function=loop_head->function;
    t->source_location=loop_head->source_location;
    t->code=code_assignt(lhs, rhs);
    t->code.add_source_location()=loop_head->source_location;
  }
}
void string_instrumentationt::do_sprintf(
  goto_programt &dest,
  goto_programt::targett target,
  code_function_callt &call)
{
  const code_function_callt::argumentst &arguments=call.arguments();
    
  if(arguments.size()<2)
  {
    error().source_location=target->source_location;
    error() << "sprintf expected to have two or more arguments" << eom;
    throw 0;
  }
  
  goto_programt tmp;
  
  goto_programt::targett assertion=tmp.add_instruction();  
  assertion->source_location=target->source_location;
  assertion->source_location.set_property_class("string");  
  assertion->source_location.set_comment("sprintf buffer overflow");
  
  // in the abstract model, we have to report a 
  // (possibly false) positive here
  assertion->make_assertion(false_exprt());
  
  do_format_string_read(tmp, target, arguments, 1, 2, "sprintf");
  
  if(call.lhs().is_not_nil())
  {
    goto_programt::targett return_assignment=tmp.add_instruction(ASSIGN);
    return_assignment->source_location=target->source_location;
    
    exprt rhs=side_effect_expr_nondett(call.lhs().type());
    rhs.add_source_location()=target->source_location;
      
    return_assignment->code=code_assignt(call.lhs(), rhs);
  }
  
  target->make_skip();
  dest.insert_before_swap(target, tmp);
}
void goto_convertt::do_atomic_end(
  const exprt &lhs,
  const exprt &function,
  const exprt::operandst &arguments,
  goto_programt &dest)
{
  if(lhs.is_not_nil())
  {
    err_location(lhs);
    throw "atomic_end does not expect an LHS";
  }

  if(!arguments.empty())
  {
    err_location(function);
    throw "atomic_end takes no arguments";
  }

  goto_programt::targett t=dest.add_instruction(ATOMIC_END);
  t->source_location=function.source_location();
}
Example #15
0
static bool skip_loops(
  goto_programt &goto_program,
  const loop_idst &loop_ids,
  messaget &message)
{
  loop_idst::const_iterator l_it=loop_ids.begin();
  Forall_goto_program_instructions(it, goto_program)
  {
    if(l_it==loop_ids.end())
      break;
    if(!it->is_backwards_goto())
      continue;

    const unsigned loop_id=it->loop_number;
    if(*l_it<loop_id)
      break; // error handled below
    if(*l_it>loop_id)
      continue;

    goto_programt::targett loop_head=it->get_target();
    goto_programt::targett next=it;
    ++next;
    assert(next!=goto_program.instructions.end());

    goto_programt::targett g=goto_program.insert_before(loop_head);
    g->make_goto(next, true_exprt());
    g->source_location=loop_head->source_location;
    g->function=loop_head->function;

    ++l_it;
  }
  if(l_it!=loop_ids.end())
  {
    message.error() << "Loop " << *l_it << " not found"
                    << messaget::eom;
    return true;
  }

  return false;
}
Example #16
0
void goto_inlinet::parameter_destruction(
  const source_locationt &source_location,
  const irep_idt &function_name,
  const code_typet &code_type,
  goto_programt &dest)
{
  const code_typet::parameterst &parameter_types=
    code_type.parameters();
  
  // iterates over the types of the parameters
  for(code_typet::parameterst::const_iterator
      it=parameter_types.begin();
      it!=parameter_types.end();
      it++)
  {
    const code_typet::parametert &parameter=*it;

    const irep_idt &identifier=parameter.get_identifier();

    if(identifier==irep_idt())
    {
      error().source_location=source_location;
      error() << "no identifier for function parameter" << eom;
      throw 0;
    }

    {
      const symbolt &symbol=ns.lookup(identifier);

      goto_programt::targett dead=dest.add_instruction();
      dead->make_dead();
      dead->code=code_deadt(symbol.symbol_expr());
      dead->code.add_source_location()=source_location;
      dead->source_location=source_location;
      dead->function=function_name; 
    }
  }
}
void remove_function_pointerst::fix_return_type(
  code_function_callt &function_call,
  goto_programt &dest)
{
  // are we returning anything at all?
  if(function_call.lhs().is_nil())
    return;

  const code_typet &code_type=
    to_code_type(ns.follow(function_call.function().type()));

  // type already ok?
  if(type_eq(
       function_call.lhs().type(),
       code_type.return_type(), ns))
    return;

  symbolt &tmp_symbol=
    get_fresh_aux_symbol(
      code_type.return_type(),
      "remove_function_pointers",
      "tmp_return_val",
      function_call.source_location(),
      irep_idt(),
      symbol_table);

  symbol_exprt tmp_symbol_expr;
  tmp_symbol_expr.type()=tmp_symbol.type;
  tmp_symbol_expr.set_identifier(tmp_symbol.name);

  exprt old_lhs=function_call.lhs();
  function_call.lhs()=tmp_symbol_expr;

  goto_programt::targett t_assign=dest.add_instruction();
  t_assign->make_assignment();
  t_assign->code=code_assignt(
    old_lhs, typecast_exprt(tmp_symbol_expr, old_lhs.type()));
}
void goto_program_dereferencet::dereference_program(
  goto_programt &goto_program,
  bool checks_only)
{
  for(goto_programt::instructionst::iterator
      it=goto_program.instructions.begin();
      it!=goto_program.instructions.end();
      it++)
  {
    new_code.clear();
    assertions.clear();

    dereference_instruction(it, checks_only);

    // insert new instructions
    while(!new_code.instructions.empty())
    {
      goto_program.insert_before_swap(it, new_code.instructions.front());
      new_code.instructions.pop_front();
      it++;
    }
  }
}
Example #19
0
void value_set_analysis_fivrt::add_vars(
  const goto_programt &goto_program)
{
  typedef std::list<value_set_fivrt::entryt> entry_listt;

  // get the globals
  entry_listt globals;
  get_globals(globals);

  // get the locals
  goto_programt::decl_identifierst locals;
  goto_program.get_decl_identifiers(locals);

  // cache the list for the locals to speed things up
  typedef std::unordered_map<irep_idt, entry_listt, irep_id_hash> entry_cachet;
  entry_cachet entry_cache;

  value_set_fivrt &v=state.value_set;
  v.add_vars(globals);

  for(auto l : locals)
  {
    // cache hit?
    entry_cachet::const_iterator e_it=entry_cache.find(l);

    if(e_it==entry_cache.end())
    {
      const symbolt &symbol=ns.lookup(l);

      std::list<value_set_fivrt::entryt> &entries=entry_cache[l];
      get_entries(symbol, entries);
      v.add_vars(entries);
    }
    else
      v.add_vars(e_it->second);
  }
}
Example #20
0
void goto_convertt::convert_msc_try_finally(
  const codet &code,
  goto_programt &dest)
{
  if(code.operands().size()!=2)
  {
    error().source_location=code.find_source_location();
    error() << "msc_try_finally expects two arguments" << eom;
    throw 0;
  }
  
  goto_programt tmp;
  tmp.add_instruction(SKIP)->source_location=code.source_location();

  {  
    // save 'leave' target
    leave_targett leave_target(targets);
    targets.set_leave(tmp.instructions.begin());
    
    // first put 'finally' code onto destructor stack
    targets.destructor_stack.push_back(to_code(code.op1()));
  
    // do 'try' code
    convert(to_code(code.op0()), dest);

    // pop 'finally' from destructor stack
    targets.destructor_stack.pop_back();
    
    // 'leave' target gets restored here
  }

  // now add 'finally' code
  convert(to_code(code.op1()), dest);
  
  // this is the target for 'leave'
  dest.destructive_append(tmp);
}
Example #21
0
void remove_unreachable(goto_programt &goto_program)
{
  std::set<goto_programt::targett> reachable;
  std::stack<goto_programt::targett> working;

  working.push(goto_program.instructions.begin());

  while(!working.empty())
  {
    goto_programt::targett t=working.top();
    working.pop();

    if(reachable.find(t)==reachable.end() &&
       t!=goto_program.instructions.end())
    {
      reachable.insert(t);
      goto_programt::targetst successors;
      goto_program.get_successors(t, successors);

      for(goto_programt::targetst::const_iterator
          s_it=successors.begin();
          s_it!=successors.end();
          s_it++)
        working.push(*s_it);
    }
  }

  // make all unreachable code a skip
  // unless it's an 'end_function'

  Forall_goto_program_instructions(it, goto_program)
  {
    if(reachable.find(it)==reachable.end() &&
       !it->is_end_function())
      it->make_skip();
  }
}
Example #22
0
void goto_convertt::convert_CPROVER_try_catch(
  const codet &code,
  goto_programt &dest)
{
  if(code.operands().size()!=2)
  {
    error().source_location=code.find_source_location();
    error() << "CPROVER_try_catch expects two arguments" << eom;
    throw 0;
  }

  // this is where we go after 'throw'
  goto_programt tmp;
  tmp.add_instruction(SKIP)->source_location=code.source_location();

  // set 'throw' target
  throw_targett throw_target(targets);
  targets.set_throw(tmp.instructions.begin());
  
  // now put 'catch' code onto destructor stack
  code_ifthenelset catch_code;
  catch_code.cond()=exception_flag();
  catch_code.add_source_location()=code.source_location();
  catch_code.then_case()=to_code(code.op1());

  targets.destructor_stack.push_back(catch_code);

  // now convert 'try' code
  convert(to_code(code.op0()), dest);

  // pop 'catch' code off stack
  targets.destructor_stack.pop_back();
  
  // add 'throw' target
  dest.destructive_append(tmp);
}
Example #23
0
void string_instrumentationt::do_strrchr(
  goto_programt &dest,
  goto_programt::targett target,
  code_function_callt &call)
{
  const code_function_callt::argumentst &arguments=call.arguments();

  if(arguments.size()!=2)
  {
    err_location(target->location);
    throw "strrchr expected to have two arguments";
  }
  
  goto_programt tmp;

  goto_programt::targett assertion=tmp.add_instruction();
  assertion->make_assertion(is_zero_string(arguments[0]));
  assertion->location=target->location;
  assertion->location.set("property", "string");
  assertion->location.set("comment", "zero-termination of string argument of strrchr");

  target->make_skip();
  dest.insert_before_swap(target, tmp);
}
Example #24
0
void goto_convertt::convert_msc_leave(
  const codet &code,
  goto_programt &dest)
{
  if(!targets.leave_set)
  {
    err_location(code);
    throw "leave without target";
  }
  
  // need to process destructor stack
  for(unsigned d=targets.destructor_stack.size();
      d!=targets.leave_stack_size;
      d--)
  {
    codet d_code=targets.destructor_stack[d-1];
    d_code.add_source_location()=code.source_location();
    convert(d_code, dest);
  }

  goto_programt::targett t=dest.add_instruction();
  t->make_goto(targets.leave_target);
  t->source_location=code.source_location();
}
Example #25
0
void remove_skip(goto_programt &goto_program)
{
  typedef std::map<goto_programt::targett, goto_programt::targett> new_targetst;
  new_targetst new_targets;

  // remove skip statements

  for(goto_programt::instructionst::iterator
      it=goto_program.instructions.begin();
      it!=goto_program.instructions.end();)
  {
    goto_programt::targett old_target=it;

    // for collecting labels
    std::list<irep_idt> labels;

    while(is_skip(it))
    {
      // don't remove the last skip statement,
      // it could be a target
      if(it==--goto_program.instructions.end())
        break;

      // save labels
      labels.splice(labels.end(), it->labels);
      it++;
    }

    goto_programt::targett new_target=it;

    // save labels
    it->labels.splice(it->labels.begin(), labels);

    if(new_target!=old_target)
    {
      while(new_target!=old_target)
      {
        // remember the old targets
        new_targets[old_target]=new_target;
        old_target=goto_program.instructions.erase(old_target);
      }
    }
    else
      it++;
  }

  // adjust gotos

  Forall_goto_program_instructions(i_it, goto_program)
    if(i_it->is_goto())
    {
      for(goto_programt::instructiont::targetst::iterator
          t_it=i_it->targets.begin();
          t_it!=i_it->targets.end();
          t_it++)
      {
        new_targetst::const_iterator
          result=new_targets.find(*t_it);

        if(result!=new_targets.end())
          *t_it=result->second;
      }
    }

  // remove the last skip statement unless it's a target
  goto_program.compute_incoming_edges();

  if(!goto_program.instructions.empty() &&
     is_skip(--goto_program.instructions.end()) &&
     !goto_program.instructions.back().is_target())
    goto_program.instructions.pop_back();
}
Example #26
0
void goto_inlinet::parameter_assignments(
  const locationt &location,
  const code_typet &code_type,
  const exprt::operandst &arguments,
  goto_programt &dest)
{
  // iterates over the operands
  exprt::operandst::const_iterator it1=arguments.begin();

  goto_programt::local_variablest local_variables;
  
  const code_typet::argumentst &argument_types=
    code_type.arguments();
  
  // iterates over the types of the arguments
  for(code_typet::argumentst::const_iterator
      it2=argument_types.begin();
      it2!=argument_types.end();
      it2++)
  {
    // if you run out of actual arguments there was a mismatch
    if(it1==arguments.end())
    {
      err_location(location);
      throw "function call: not enough arguments";
    }

    const exprt &argument=static_cast<const exprt &>(*it2);

    // this is the type the n-th argument should be
    const typet &arg_type=ns.follow(argument.type());

    const irep_idt &identifier=argument.cmt_identifier();

    if(identifier=="")
    {
      err_location(location);
      throw "no identifier for function argument";
    }

    {
      const symbolt &symbol=ns.lookup(identifier);

      goto_programt::targett decl=dest.add_instruction();
      decl->make_other();
      exprt tmp = code_declt(symbol_expr(symbol));
      migrate_expr(tmp, decl->code);
      decl->location=location;
      decl->function=location.get_function(); 
      decl->local_variables=local_variables;
    }

    local_variables.insert(identifier);
    
    // nil means "don't assign"
    if(it1->is_nil())
    {    
    }
    else
    {
      // this is the actual parameter
      exprt actual(*it1);

      // it should be the same exact type
      type2tc arg_type_2, actual_type_2;
      migrate_type(arg_type, arg_type_2);
      migrate_type(actual.type(), actual_type_2);
      if (!base_type_eq(arg_type_2, actual_type_2, ns))
      {
        const typet &f_argtype = ns.follow(arg_type);
        const typet &f_acttype = ns.follow(actual.type());
        
        // we are willing to do some conversion
        if((f_argtype.id()=="pointer" &&
            f_acttype.id()=="pointer") ||
           (f_argtype.is_array() &&
            f_acttype.id()=="pointer" &&
            f_argtype.subtype()==f_acttype.subtype()))
        {
          actual.make_typecast(arg_type);
        }
        else if((f_argtype.id()=="signedbv" ||
            f_argtype.id()=="unsignedbv" ||
            f_argtype.is_bool()) &&
           (f_acttype.id()=="signedbv" ||
            f_acttype.id()=="unsignedbv" ||
            f_acttype.is_bool()))  
        {
          actual.make_typecast(arg_type);
        }
        else
        {
          err_location(location);

          str << "function call: argument `" << identifier
              << "' type mismatch: got "
              << from_type(ns, identifier, it1->type())
              << ", expected "
              << from_type(ns, identifier, arg_type);
          throw 0;
        }
      }

      // adds an assignment of the actual parameter to the formal parameter
      code_assignt assignment(symbol_exprt(identifier, arg_type), actual);
      assignment.location()=location;

      dest.add_instruction(ASSIGN);
      dest.instructions.back().location=location;
      migrate_expr(assignment, dest.instructions.back().code);
      dest.instructions.back().local_variables=local_variables;
      dest.instructions.back().function=location.get_function();      
    }

    it1++;
  }

  if(it1!=arguments.end())
  {
    // too many arguments -- we just ignore that, no harm done
  }
}
void remove_virtual_functionst::remove_virtual_function(
  goto_programt &goto_program,
  goto_programt::targett target)
{
  const code_function_callt &code=
    to_code_function_call(target->code);

  const auto &vcall_source_loc=target->source_location;

  const exprt &function=code.function();
  assert(function.id()==ID_virtual_function);
  assert(!code.arguments().empty());

  functionst functions;
  get_functions(function, functions);

  if(functions.empty())
  {
    target->make_skip();
    return; // give up
  }

  // only one option?
  if(functions.size()==1)
  {
    assert(target->is_function_call());
    if(functions.begin()->symbol_expr==symbol_exprt())
      target->make_skip();
    else
      to_code_function_call(target->code).function()=
        functions.begin()->symbol_expr;
    return;
  }

  // the final target is a skip
  goto_programt final_skip;

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

  t_final->make_skip();

  // build the calls and gotos

  goto_programt new_code_calls;
  goto_programt new_code_gotos;

  exprt this_expr=code.arguments()[0];
  // If necessary, cast to the last candidate function to
  // get the object's clsid. By the structure of get_functions,
  // this is the parent of all other classes under consideration.
  const auto &base_classid=functions.back().class_id;
  const auto &base_function_symbol=functions.back().symbol_expr;
  symbol_typet suggested_type(base_classid);
  exprt c_id2=get_class_identifier_field(this_expr, suggested_type, ns);

  std::map<irep_idt, goto_programt::targett> calls;
  // Note backwards iteration, to get the least-derived candidate first.
  for(auto it=functions.crbegin(), itend=functions.crend(); it!=itend; ++it)
  {
    const auto &fun=*it;
    auto insertit=calls.insert(
      {fun.symbol_expr.get_identifier(), goto_programt::targett()});

    // Only create one call sequence per possible target:
    if(insertit.second)
    {
      goto_programt::targett t1=new_code_calls.add_instruction();
      t1->source_location=vcall_source_loc;
      if(!fun.symbol_expr.get_identifier().empty())
      {
      // call function
        t1->make_function_call(code);
        auto &newcall=to_code_function_call(t1->code);
        newcall.function()=fun.symbol_expr;
        pointer_typet need_type(symbol_typet(fun.symbol_expr.get(ID_C_class)));
        if(!type_eq(newcall.arguments()[0].type(), need_type, ns))
          newcall.arguments()[0].make_typecast(need_type);
      }
      else
      {
        // No definition for this type; shouldn't be possible...
        t1->make_assertion(false_exprt());
      }
      insertit.first->second=t1;
      // goto final
      goto_programt::targett t3=new_code_calls.add_instruction();
      t3->source_location=vcall_source_loc;
      t3->make_goto(t_final, true_exprt());
    }

    // If this calls the base function we just fall through.
    // Otherwise branch to the right call:
    if(fun.symbol_expr!=base_function_symbol)
    {
      exprt c_id1=constant_exprt(fun.class_id, string_typet());
      goto_programt::targett t4=new_code_gotos.add_instruction();
      t4->source_location=vcall_source_loc;
      t4->make_goto(insertit.first->second, equal_exprt(c_id1, c_id2));
    }
  }

  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)
  {
    const irep_idt property_class=it->source_location.get_property_class();
    const 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);
  }

  goto_programt::targett next_target=target;
  next_target++;

  goto_program.destructive_insert(next_target, new_code);

  // finally, kill original invocation
  target->make_skip();
}
Example #28
0
void goto_checkt::goto_check(goto_functiont &goto_function)
{
  {
    const symbolt *init_symbol;
    if(!ns.lookup(CPROVER_PREFIX "initialize", init_symbol))
      mode=init_symbol->mode;
  }

  assertions.clear();

  local_bitvector_analysist local_bitvector_analysis_obj(goto_function);
  local_bitvector_analysis=&local_bitvector_analysis_obj;

  goto_programt &goto_program=goto_function.body;

  Forall_goto_program_instructions(it, goto_program)
  {
    t=it;
    goto_programt::instructiont &i=*it;

    new_code.clear();

    // we clear all recorded assertions if
    // 1) we want to generate all assertions or
    // 2) the instruction is a branch target
    if(retain_trivial ||
       i.is_target())
      assertions.clear();

    check(i.guard);

    // magic ERROR label?
    for(optionst::value_listt::const_iterator
        l_it=error_labels.begin();
        l_it!=error_labels.end();
        l_it++)
    {
      if(std::find(i.labels.begin(), i.labels.end(), *l_it)!=i.labels.end())
      {
        goto_program_instruction_typet type=
          enable_assert_to_assume?ASSUME:ASSERT;

        goto_programt::targett t=new_code.add_instruction(type);

        t->guard=false_exprt();
        t->source_location=i.source_location;
        t->source_location.set_property_class("error label");
        t->source_location.set_comment("error label "+*l_it);
        t->source_location.set("user-provided", true);
      }
    }

    if(i.is_other())
    {
      const irep_idt &statement=i.code.get(ID_statement);

      if(statement==ID_expression)
      {
        check(i.code);
      }
      else if(statement==ID_printf)
      {
        forall_operands(it, i.code)
          check(*it);
      }
    }
    else if(i.is_assign())
    {
      const code_assignt &code_assign=to_code_assign(i.code);

      check(code_assign.lhs());
      check(code_assign.rhs());

      // the LHS might invalidate any assertion
      invalidate(code_assign.lhs());
    }
    else if(i.is_function_call())
    {
      const code_function_callt &code_function_call=
        to_code_function_call(i.code);

      // for Java, need to check whether 'this' is null
      // on non-static method invocations
      if(mode==ID_java &&
         enable_pointer_check &&
         !code_function_call.arguments().empty() &&
         code_function_call.function().type().id()==ID_code &&
         to_code_type(code_function_call.function().type()).has_this())
      {
        exprt pointer=code_function_call.arguments()[0];

        local_bitvector_analysist::flagst flags=
          local_bitvector_analysis->get(t, pointer);

        if(flags.is_unknown() || flags.is_null())
        {
          notequal_exprt not_eq_null(pointer, gen_zero(pointer.type()));

          add_guarded_claim(
            not_eq_null,
            "this is null on method invokation",
            "pointer dereference",
            i.source_location,
            pointer,
            guardt());
        }
      }

      forall_operands(it, code_function_call)
        check(*it);

      // the call might invalidate any assertion
      assertions.clear();
    }
    else if(i.is_return())
    {
      if(i.code.operands().size()==1)
      {
        check(i.code.op0());
        // the return value invalidate any assertion
        invalidate(i.code.op0());
      }
    }
    else if(i.is_throw())
    {
      if(i.code.get_statement()==ID_expression &&
         i.code.operands().size()==1 &&
         i.code.op0().operands().size()==1)
      {
        // must not throw NULL

        exprt pointer=i.code.op0().op0();

        if(pointer.type().subtype().get(ID_identifier)!="java::java.lang.AssertionError")
        {
          notequal_exprt not_eq_null(pointer, gen_zero(pointer.type()));

          add_guarded_claim(
            not_eq_null,
            "throwing null",
            "pointer dereference",
            i.source_location,
            pointer,
            guardt());
        }
      }

      // this has no successor
      assertions.clear();
    }
    else if(i.is_assert())
    {
      if(i.source_location.get_bool("user-provided") &&
         i.source_location.get_property_class()!="error label" &&
         !enable_assertions)
        i.type=SKIP;
    }
    else if(i.is_assume())
    {
      if(!enable_assumptions)
        i.type=SKIP;
    }
    else if(i.is_dead())
    {
      if(enable_pointer_check)
      {
        assert(i.code.operands().size()==1);
        const symbol_exprt &variable=to_symbol_expr(i.code.op0());

        // is it dirty?
        if(local_bitvector_analysis->dirty(variable))
        {
          // need to mark the dead variable as dead
          goto_programt::targett t=new_code.add_instruction(ASSIGN);
          exprt address_of_expr=address_of_exprt(variable);
          exprt lhs=ns.lookup(CPROVER_PREFIX "dead_object").symbol_expr();
          if(!base_type_eq(lhs.type(), address_of_expr.type(), ns))
            address_of_expr.make_typecast(lhs.type());
          exprt rhs=if_exprt(
            side_effect_expr_nondett(bool_typet()), address_of_expr, lhs, lhs.type());
          t->source_location=i.source_location;
          t->code=code_assignt(lhs, rhs);
          t->code.add_source_location()=i.source_location;
        }
      }
    }
    else if(i.is_end_function())
    {
      if(i.function==goto_functionst::entry_point() &&
         enable_memory_leak_check)
      {
        const symbolt &leak=ns.lookup(CPROVER_PREFIX "memory_leak");
        const symbol_exprt leak_expr=leak.symbol_expr();

        // add self-assignment to get helpful counterexample output
        goto_programt::targett t=new_code.add_instruction();
        t->make_assignment();
        t->code=code_assignt(leak_expr, leak_expr);

        source_locationt source_location;
        source_location.set_function(i.function);

        equal_exprt eq(leak_expr, gen_zero(ns.follow(leak.type)));
        add_guarded_claim(
          eq,
          "dynamically allocated memory never freed",
          "memory-leak",
          source_location,
          eq,
          guardt());
      }
    }

    for(goto_programt::instructionst::iterator
        i_it=new_code.instructions.begin();
        i_it!=new_code.instructions.end();
        i_it++)
    {
      if(i_it->source_location.is_nil())
      {
        i_it->source_location.id(irep_idt());

        if(it->source_location.get_file()!=irep_idt())
          i_it->source_location.set_file(it->source_location.get_file());

        if(it->source_location.get_line()!=irep_idt())
          i_it->source_location.set_line(it->source_location.get_line());

        if(it->source_location.get_function()!=irep_idt())
          i_it->source_location.set_function(it->source_location.get_function());

        if(it->source_location.get_column()!=irep_idt())
          i_it->source_location.set_column(it->source_location.get_column());
      }

      if(i_it->function==irep_idt()) i_it->function=it->function;
    }

    // insert new instructions -- make sure targets are not moved

    while(!new_code.instructions.empty())
    {
      goto_program.insert_before_swap(it, new_code.instructions.front());
      new_code.instructions.pop_front();
      it++;
    }
  }
Example #29
0
void convert( const irept &irep, goto_programt &program )
{
  assert(irep.id()=="goto-program");

  program.instructions.clear();

  std::list< std::list<unsigned> > number_targets_list;

  // convert instructions back
  const irept::subt &subs = irep.get_sub();
  for (irept::subt::const_iterator it=subs.begin();
       it!=subs.end();
       it++)
  {
    program.instructions.push_back(goto_programt::instructiont());
    convert(*it, program.instructions.back());

    number_targets_list.push_back(std::list<unsigned>());
    const irept &targets=it->find(ID_targets);
    const irept::subt &tsubs=targets.get_sub();
    for (irept::subt::const_iterator tit=tsubs.begin();
         tit!=tsubs.end();
         tit++)
    {
      number_targets_list.back().push_back(
          unsafe_string2unsigned(tit->id_string()));
    }
  }

  program.compute_location_numbers();

  // resolve targets
  std::list< std::list<unsigned> >::iterator nit=
        number_targets_list.begin();
  for(goto_programt::instructionst::iterator lit=
        program.instructions.begin();
      lit!=program.instructions.end() && nit!=number_targets_list.end();
      lit++, nit++)
  {
    for (std::list<unsigned>::iterator tit=nit->begin();
         tit!=nit->end();
         tit++)
    {
      goto_programt::targett fit=program.instructions.begin();
      for(;fit!=program.instructions.end();fit++)
      {
        if (fit->location_number==*tit)
        {
          lit->targets.push_back(fit);
          break;
        }
      }

      if (fit==program.instructions.end())
      {
        std::cout << "Warning: could not resolve target link "
                  << "during irep->goto_program translation." << std::endl;
        throw 0;
      }
    }
  }

  program.update();
}
Example #30
0
void goto_inlinet::replace_return(
  goto_programt &dest,
  const exprt &lhs,
  const exprt &constrain __attribute__((unused)) /* ndebug */)
{
  for(goto_programt::instructionst::iterator
      it=dest.instructions.begin();
      it!=dest.instructions.end();
      it++)
  {
    if(it->is_return())
    {
      if(lhs.is_not_nil())
      {
        goto_programt tmp;
        goto_programt::targett assignment=tmp.add_instruction(ASSIGN);
        
        const code_return2t &ret = to_code_return2t(it->code);
        code_assignt code_assign(lhs, migrate_expr_back(ret.operand));

        // this may happen if the declared return type at the call site
        // differs from the defined return type
        if(code_assign.lhs().type()!=
           code_assign.rhs().type())
          code_assign.rhs().make_typecast(code_assign.lhs().type());

        migrate_expr(code_assign, assignment->code);
        assignment->location=it->location;
        assignment->local_variables=it->local_variables;
        assignment->function=it->location.get_function();