void goto_checkt::check_rec(const exprt &expr, guardt &guard, bool address)
{
if (address)
{
if (expr.id() == "dereference")
{
assert(expr.operands().size() == 1);
check_rec(expr.op0(), guard, false);
}
else if (expr.id() == "index")
{
assert(expr.operands().size() == 2);
check_rec(expr.op0(), guard, true);
check_rec(expr.op1(), guard, false);
}
else
{
forall_operands(it, expr)
check_rec(*it, guard, true);
}
return;
}
if (expr.is_address_of())
{
assert(expr.operands().size() == 1);
check_rec(expr.op0(), guard, true);
return;
}
else if (expr.is_and() || expr.id() == "or")
{
if (!expr.is_boolean())
throw expr.id_string() + " must be Boolean, but got " + expr.pretty();
unsigned old_guards = guard.size();
for (unsigned i = 0; i < expr.operands().size(); i++)
{
const exprt &op = expr.operands()[i];
if (!op.is_boolean())
throw expr.id_string() + " takes Boolean operands only, but got "
+ op.pretty();
check_rec(op, guard, false);
if (expr.id() == "or")
{
exprt tmp(op);
tmp.make_not();
expr2tc tmp_expr;
migrate_expr(tmp, tmp_expr);
guard.move(tmp_expr);
}
else
{
expr2tc tmp;
migrate_expr(op, tmp);
guard.add(tmp);
}
}
guard.resize(old_guards);
return;
}
else if (expr.id() == "if")
{
if (expr.operands().size() != 3)
throw "if takes three arguments";
if (!expr.op0().is_boolean())
{
std::string msg = "first argument of if must be boolean, but got "
+ expr.op0().to_string();
throw msg;
}
check_rec(expr.op0(), guard, false);
{
unsigned old_guard = guard.size();
expr2tc tmp;
migrate_expr(expr.op0(), tmp);
guard.add(tmp);
check_rec(expr.op1(), guard, false);
guard.resize(old_guard);
}
{
unsigned old_guard = guard.size();
exprt tmp(expr.op0());
tmp.make_not();
expr2tc tmp_expr;
migrate_expr(tmp, tmp_expr);
guard.move(tmp_expr);
check_rec(expr.op2(), guard, false);
guard.resize(old_guard);
}
return;
}
forall_operands(it, expr)
check_rec(*it, guard, false);
if (expr.id() == "index")
{
bounds_check(expr, guard);
}
else if (expr.id() == "/")
{
div_by_zero_check(expr, guard);
if (expr.type().id() == "signedbv")
{
overflow_check(expr, guard);
}
else if (expr.type().id() == "floatbv")
{
nan_check(expr, guard);
}
}
else if (expr.id() == "+" || expr.id() == "-" || expr.id() == "*"
|| expr.id() == "unary-" || expr.id() == "typecast")
{
if (expr.type().id() == "signedbv")
{
overflow_check(expr, guard);
}
else if (expr.type().id() == "floatbv")
{
nan_check(expr, guard);
}
}
else if (expr.id() == "<=" || expr.id() == "<" || expr.id() == ">="
|| expr.id() == ">")
{
pointer_rel_check(expr, guard);
}
else if (expr.id() == "mod")
{
div_by_zero_check(expr, guard);
if (expr.type().id() == "signedbv")
{
overflow_check(expr, guard);
}
else if (expr.type().id() == "floatbv")
{
nan_check(expr, guard);
}
}
}
