void ExprSMTLIBPrinter::scan(const ref<Expr> &e) {
if (e.isNull()) {
std::cerr << "ExprSMTLIBPrinter::scan() : Found NULL expression!"
<< std::endl;
return;
}
if (isa<ConstantExpr>(e))
return; // we don't need to scan simple constants
if (const ReadExpr *re = dyn_cast<ReadExpr>(e)) {
// Attempt to insert array and if array wasn't present before do more things
if (usedArrays.insert(re->updates.root).second) {
// check if the array is constant
if (re->updates.root->isConstantArray())
haveConstantArray = true;
// scan the update list
scanUpdates(re->updates.head);
}
}
// recurse into the children
Expr *ep = e.get();
for (unsigned int i = 0; i < ep->getNumKids(); i++)
scan(ep->getKid(i));
}
void ExprSMTLIBLetPrinter::scan(const ref<Expr> &e) {
if (isa<ConstantExpr>(e))
return; // we don't need to scan simple constants
if (firstEO.insert(e).second) {
// We've not seen this expression before
if (const ReadExpr *re = dyn_cast<ReadExpr>(e)) {
// Attempt to insert array and if array wasn't present before do more
// things
if (usedArrays.insert(re->updates.root).second) {
// check if the array is constant
if (re->updates.root->isConstantArray())
haveConstantArray = true;
// scan the update list
scanUpdates(re->updates.head);
}
}
// recurse into the children
Expr *ep = e.get();
for (unsigned int i = 0; i < ep->getNumKids(); i++)
scan(ep->getKid(i));
} else {
/* We must of seen the expression before. Add it to
* the set of twoOrMoreOccurances. We don't need to
* check if the insertion fails.
*/
twoOrMoreEO.insert(e);
}
}
void klee::findReads(ref<Expr> e,
bool visitUpdates,
std::vector< ref<ReadExpr> > &results) {
// Invariant: \forall_{i \in stack} !i.isConstant() && i \in visited
std::vector< ref<Expr> > stack;
ExprHashSet visited;
std::set<const UpdateNode *> updates;
if (!isa<ConstantExpr>(e)) {
visited.insert(e);
stack.push_back(e);
}
while (!stack.empty()) {
ref<Expr> top = stack.back();
stack.pop_back();
if (ReadExpr *re = dyn_cast<ReadExpr>(top)) {
// We memoized so can just add to list without worrying about
// repeats.
results.push_back(re);
if (!isa<ConstantExpr>(re->index) &&
visited.insert(re->index).second)
stack.push_back(re->index);
if (visitUpdates) {
// XXX this is probably suboptimal. We want to avoid a potential
// explosion traversing update lists which can be quite
// long. However, it seems silly to hash all of the update nodes
// especially since we memoize all the expr results anyway. So
// we take a simple approach of memoizing the results for the
// head, which often will be shared among multiple nodes.
if (updates.insert(re->updates.head).second) {
for (const UpdateNode *un=re->updates.head; un; un=un->next) {
if (!isa<ConstantExpr>(un->index) &&
visited.insert(un->index).second)
stack.push_back(un->index);
if (!isa<ConstantExpr>(un->value) &&
visited.insert(un->value).second)
stack.push_back(un->value);
}
}
}
} else if (!isa<ConstantExpr>(top)) {
Expr *e = top.get();
for (unsigned i=0; i<e->getNumKids(); i++) {
ref<Expr> k = e->getKid(i);
if (!isa<ConstantExpr>(k) &&
visited.insert(k).second)
stack.push_back(k);
}
}
}
}
ExprVisitor::Action ExprEvaluator::visitExpr(const Expr &e) {
// Evaluate all constant expressions here, in case they weren't folded in
// construction. Don't do this for reads though, because we want them to go to
// the normal rewrite path.
unsigned N = e.getNumKids();
if (!N || isa<ReadExpr>(e))
return Action::doChildren();
for (unsigned i = 0; i != N; ++i)
if (!isa<ConstantExpr>(e.getKid(i)))
return Action::doChildren();
ref<Expr> Kids[3];
for (unsigned i = 0; i != N; ++i) {
assert(i < 3);
Kids[i] = e.getKid(i);
}
return Action::changeTo(e.rebuild(Kids));
}