Where* WhereInvariant::Make(TypeCSU *csu, Exp *lval, Bit *bit)
{
Assert(bit);
Bit *new_bit;
if (csu) {
Variable *this_var = Variable::Make(NULL, VK_This, NULL, 0, NULL);
Exp *this_exp = Exp::MakeVar(this_var);
Exp *this_drf = Exp::MakeDrf(this_exp);
new_bit = TranslateHeapBit(lval, this_drf, false, bit);
this_drf->DecRef();
}
else {
new_bit = TranslateHeapBit(NULL, NULL, false, bit);
}
Where *res = NULL;
if (new_bit) {
// additionally visit it to make sure we can find all lvalues.
CheckInvariantVisitor visitor;
new_bit->DoVisit(&visitor);
if (!visitor.exclude)
res = new WhereInvariant(csu, NULL, new_bit);
new_bit->DecRef();
}
return res;
}
void WhereInvariant::AssertRecursive(CheckerFrame *frame, Exp *exp)
{
if (m_csu == NULL)
return;
Exp *read_csu = GetWriteCSU(exp);
if (read_csu == NULL)
return;
Variable *this_var = Variable::Make(NULL, VK_This, NULL, 0, NULL);
Exp *this_exp = Exp::MakeVar(this_var);
Exp *this_drf = Exp::MakeDrf(this_exp);
Bit *entry_bit = TranslateHeapBit(this_drf, read_csu, false, m_bit);
frame->AddAssert(entry_bit);
}
void WhereInvariant::GetHeapBits(CheckerFrame *write_frame,
Exp *write_csu, Exp *base_csu,
Bit **base_bit, GuardBitVector *res)
{
BlockMemory *mcfg = write_frame->Memory();
Exp *old_lval = NULL;
if (m_csu) {
Variable *this_var = Variable::Make(NULL, VK_This, NULL, 0, NULL);
Exp *old_this = Exp::MakeVar(this_var);
old_lval = Exp::MakeDrf(old_this);
}
Bit *exit_bit = TranslateHeapBit(old_lval, write_csu, true, m_bit);
Assert(exit_bit);
if (old_lval)
old_lval->DecRef();
// TODO: using this to get the base bit for an invariant is fairly
// hacked up, but for now we can't do this correctly as the base bit
// needs to be relative to the CFG exit point, not the point where
// any writes occur at. for now just get the displayable point for
// the base CSU, and hope that means the same thing at exit as at
// the point of the write.
Bit *new_bit = BitConvertExitClobber(m_bit);
if (base_csu) {
*base_bit = BitReplaceExp(new_bit, old_lval, base_csu);
new_bit->DecRef();
}
else {
*base_bit = new_bit;
}
GuardBitVector base_res;
PPoint exit_point = mcfg->GetCFG()->GetExitPoint();
mcfg->TranslateBit(TRK_Exit, exit_point, exit_bit, &base_res);
exit_bit->DecRef();
RemoveValBit(write_frame->Id(), write_frame->Memory(), base_res, res);
}
