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);
}
}
}
void rw_sett::read_write_rec(
const exprt &expr,
bool r, bool w,
const std::string &suffix,
const guardt &guard)
{
if(expr.id()=="symbol" && !expr.has_operands())
{
const symbol_exprt &symbol_expr=to_symbol_expr(expr);
const symbolt *symbol;
if(!ns.lookup(symbol_expr.get_identifier(), symbol))
{
if(!symbol->static_lifetime /*&& expr.type().id()=="pointer"*/)
{
return; // ignore for now
}
if(symbol->name=="c::__ESBMC_alloc" ||
symbol->name=="c::__ESBMC_alloc_size" ||
symbol->name=="c::stdin" ||
symbol->name=="c::stdout" ||
symbol->name=="c::stderr" ||
symbol->name=="c::sys_nerr")
{
return; // ignore for now
}
}
irep_idt object=id2string(symbol_expr.get_identifier())+suffix;
entryt &entry=entries[object];
entry.object=object;
entry.r=entry.r || r;
entry.w=entry.w || w;
entry.guard = migrate_expr_back(guard.as_expr());
}
else if(expr.id()=="member")
{
assert(expr.operands().size()==1);
const std::string &component_name=expr.component_name().as_string();
read_write_rec(expr.op0(), r, w, "."+component_name+suffix, guard);
}
else if(expr.id()=="index")
{
// we don't distinguish the array elements for now
assert(expr.operands().size()==2);
std::string tmp;
tmp = integer2string(binary2integer(expr.op1().value().as_string(), true),10);
read_write_rec(expr.op0(), r, w, "["+suffix+tmp+"]", guard);
read(expr.op1(), guard);
}
else if(expr.id()=="dereference")
{
assert(expr.operands().size()==1);
read(expr.op0(), guard);
exprt tmp(expr.op0());
expr2tc tmp_expr;
migrate_expr(tmp, tmp_expr);
dereference(target, tmp_expr, ns, value_sets);
tmp = migrate_expr_back(tmp_expr);
read_write_rec(tmp, r, w, suffix, guard);
}
else if(expr.is_address_of() ||
expr.id()=="implicit_address_of")
{
assert(expr.operands().size()==1);
}
else if(expr.id()=="if")
{
assert(expr.operands().size()==3);
read(expr.op0(), guard);
guardt true_guard(guard);
expr2tc tmp_expr;
migrate_expr(expr.op0(), tmp_expr);
true_guard.add(tmp_expr);
read_write_rec(expr.op1(), r, w, suffix, true_guard);
guardt false_guard(guard);
migrate_expr(gen_not(expr.op0()), tmp_expr);
false_guard.add(tmp_expr);
read_write_rec(expr.op2(), r, w, suffix, false_guard);
}
else
{
forall_operands(it, expr)
read_write_rec(*it, r, w, suffix, guard);
}
}