std::string array_name(
const namespacet &ns,
const exprt &expr)
{
if(expr.id()==ID_index)
{
if(expr.operands().size()!=2)
throw "index takes two operands";
return array_name(ns, expr.op0())+"[]";
}
else if(is_ssa_expr(expr))
{
const symbolt &symbol=
ns.lookup(to_ssa_expr(expr).get_object_name());
return "array `"+id2string(symbol.base_name)+"'";
}
else if(expr.id()==ID_symbol)
{
const symbolt &symbol=ns.lookup(expr);
return "array `"+id2string(symbol.base_name)+"'";
}
else if(expr.id()==ID_string_constant)
{
return "string constant";
}
else if(expr.id()==ID_member)
{
assert(expr.operands().size()==1);
return array_name(ns, expr.op0())+"."+
expr.get_string(ID_component_name);
}
return "array";
}
void value_set_dereferencet::valid_check(
const exprt &object,
const guardt &guard,
const modet mode)
{
if(!options.get_bool_option("pointer-check"))
return;
const exprt &symbol_expr=get_symbol(object);
if(symbol_expr.id()==ID_string_constant)
{
// always valid, but can't write
if(mode==modet::WRITE)
{
dereference_callback.dereference_failure(
"pointer dereference",
"write access to string constant",
guard);
}
}
else if(symbol_expr.is_nil() ||
symbol_expr.get_bool(ID_C_invalid_object))
{
// always "valid", shut up
return;
}
else if(symbol_expr.id()==ID_symbol)
{
const irep_idt identifier=
is_ssa_expr(symbol_expr)?
to_ssa_expr(symbol_expr).get_object_name():
to_symbol_expr(symbol_expr).get_identifier();
const symbolt &symbol=ns.lookup(identifier);
if(symbol.type.get_bool(ID_C_is_failed_symbol))
{
dereference_callback.dereference_failure(
"pointer dereference",
"invalid pointer",
guard);
}
#if 0
if(dereference_callback.is_valid_object(identifier))
return; // always ok
#endif
}
}
