int main(int argc, char **argv) {
assert(argc == 4);
// TODO: maybe we want to get them from prompt args
int num_vars = stoi(argv[2]);
int depth = stoi(argv[3]);
ifstream stream(argv[1]);
StateTransitionSystemLoader loader(stream);
unique_ptr<StateTransitionSystem> sts = loader.make();
State* si = sts->states()[0];
VariableAssignment vars = VariableAssignment(num_vars);
for (auto *var : sts->variables()) {
vars.set(var, false);
}
ReachabilitySet rs = computeReachabilitySet(Configuration(si, move(vars)));
size_t siex = (num_vars + 1) + pow(2, depth + 1) - 1;
cout << endl << "SIZE expected: " << siex;
size_t size = rs.size();
cout << endl << "SIZE: " << size << endl;
if (size - siex != 0) return 1;
return 0;
}
CFLAndersAAResult::FunctionInfo::FunctionInfo(const ReachabilitySet &ReachSet,
AliasAttrMap AMap) {
// Populate AttrMap
for (const auto &Mapping : AMap.mappings()) {
auto IVal = Mapping.first;
// AttrMap only cares about top-level values
if (IVal.DerefLevel == 0)
AttrMap[IVal.Val] = Mapping.second;
}
// Populate AliasMap
for (const auto &OuterMapping : ReachSet.value_mappings()) {
// AliasMap only cares about top-level values
if (OuterMapping.first.DerefLevel > 0)
continue;
auto Val = OuterMapping.first.Val;
auto &AliasList = AliasMap[Val];
for (const auto &InnerMapping : OuterMapping.second) {
// Again, AliasMap only cares about top-level values
if (InnerMapping.first.DerefLevel == 0)
AliasList.push_back(InnerMapping.first.Val);
}
// Sort AliasList for faster lookup
std::sort(AliasList.begin(), AliasList.end(), std::less<const Value *>());
}
// TODO: Populate function summary here
}
static void propagate(InstantiatedValue From, InstantiatedValue To,
MatchState State, ReachabilitySet &ReachSet,
std::vector<WorkListItem> &WorkList) {
if (From == To)
return;
if (ReachSet.insert(From, To, State))
WorkList.push_back(WorkListItem{From, To, State});
}
static AliasAttrMap buildAttrMap(const CFLGraph &Graph,
const ReachabilitySet &ReachSet) {
AliasAttrMap AttrMap;
std::vector<InstantiatedValue> WorkList, NextList;
// Initialize each node with its original AliasAttrs in CFLGraph
for (const auto &Mapping : Graph.value_mappings()) {
auto Val = Mapping.first;
auto &ValueInfo = Mapping.second;
for (unsigned I = 0, E = ValueInfo.getNumLevels(); I < E; ++I) {
auto Node = InstantiatedValue{Val, I};
AttrMap.add(Node, ValueInfo.getNodeInfoAtLevel(I).Attr);
WorkList.push_back(Node);
}
}
while (!WorkList.empty()) {
for (const auto &Dst : WorkList) {
auto DstAttr = AttrMap.getAttrs(Dst);
if (DstAttr.none())
continue;
// Propagate attr on the same level
for (const auto &Mapping : ReachSet.reachableValueAliases(Dst)) {
auto Src = Mapping.first;
if (AttrMap.add(Src, DstAttr))
NextList.push_back(Src);
}
// Propagate attr to the levels below
auto DstBelow = getNodeBelow(Graph, Dst);
while (DstBelow) {
if (AttrMap.add(*DstBelow, DstAttr)) {
NextList.push_back(*DstBelow);
break;
}
DstBelow = getNodeBelow(Graph, *DstBelow);
}
}
WorkList.swap(NextList);
NextList.clear();
}
return AttrMap;
}
static void
populateAliasMap(DenseMap<const Value *, std::vector<OffsetValue>> &AliasMap,
const ReachabilitySet &ReachSet) {
for (const auto &OuterMapping : ReachSet.value_mappings()) {
// AliasMap only cares about top-level values
if (OuterMapping.first.DerefLevel > 0)
continue;
auto Val = OuterMapping.first.Val;
auto &AliasList = AliasMap[Val];
for (const auto &InnerMapping : OuterMapping.second) {
// Again, AliasMap only cares about top-level values
if (InnerMapping.first.DerefLevel == 0)
AliasList.push_back(OffsetValue{InnerMapping.first.Val, UnknownOffset});
}
// Sort AliasList for faster lookup
llvm::sort(AliasList.begin(), AliasList.end());
}
}
static void processWorkListItem(const WorkListItem &Item, const CFLGraph &Graph,
ReachabilitySet &ReachSet, AliasMemSet &MemSet,
std::vector<WorkListItem> &WorkList) {
auto FromNode = Item.From;
auto ToNode = Item.To;
auto NodeInfo = Graph.getNode(ToNode);
assert(NodeInfo != nullptr);
// TODO: propagate field offsets
// FIXME: Here is a neat trick we can do: since both ReachSet and MemSet holds
// relations that are symmetric, we could actually cut the storage by half by
// sorting FromNode and ToNode before insertion happens.
// The newly added value alias pair may potentially generate more memory
// alias pairs. Check for them here.
auto FromNodeBelow = getNodeBelow(Graph, FromNode);
auto ToNodeBelow = getNodeBelow(Graph, ToNode);
if (FromNodeBelow && ToNodeBelow &&
MemSet.insert(*FromNodeBelow, *ToNodeBelow)) {
propagate(*FromNodeBelow, *ToNodeBelow,
MatchState::FlowFromMemAliasNoReadWrite, ReachSet, WorkList);
for (const auto &Mapping : ReachSet.reachableValueAliases(*FromNodeBelow)) {
auto Src = Mapping.first;
auto MemAliasPropagate = [&](MatchState FromState, MatchState ToState) {
if (Mapping.second.test(static_cast<size_t>(FromState)))
propagate(Src, *ToNodeBelow, ToState, ReachSet, WorkList);
};
MemAliasPropagate(MatchState::FlowFromReadOnly,
MatchState::FlowFromMemAliasReadOnly);
MemAliasPropagate(MatchState::FlowToWriteOnly,
MatchState::FlowToMemAliasWriteOnly);
MemAliasPropagate(MatchState::FlowToReadWrite,
MatchState::FlowToMemAliasReadWrite);
}
}
// This is the core of the state machine walking algorithm. We expand ReachSet
// based on which state we are at (which in turn dictates what edges we
// should examine)
// From a high-level point of view, the state machine here guarantees two
// properties:
// - If *X and *Y are memory aliases, then X and Y are value aliases
// - If Y is an alias of X, then reverse assignment edges (if there is any)
// should precede any assignment edges on the path from X to Y.
auto NextAssignState = [&](MatchState State) {
for (const auto &AssignEdge : NodeInfo->Edges)
propagate(FromNode, AssignEdge.Other, State, ReachSet, WorkList);
};
auto NextRevAssignState = [&](MatchState State) {
for (const auto &RevAssignEdge : NodeInfo->ReverseEdges)
propagate(FromNode, RevAssignEdge.Other, State, ReachSet, WorkList);
};
auto NextMemState = [&](MatchState State) {
if (auto AliasSet = MemSet.getMemoryAliases(ToNode)) {
for (const auto &MemAlias : *AliasSet)
propagate(FromNode, MemAlias, State, ReachSet, WorkList);
}
};
switch (Item.State) {
case MatchState::FlowFromReadOnly:
NextRevAssignState(MatchState::FlowFromReadOnly);
NextAssignState(MatchState::FlowToReadWrite);
NextMemState(MatchState::FlowFromMemAliasReadOnly);
break;
case MatchState::FlowFromMemAliasNoReadWrite:
NextRevAssignState(MatchState::FlowFromReadOnly);
NextAssignState(MatchState::FlowToWriteOnly);
break;
case MatchState::FlowFromMemAliasReadOnly:
NextRevAssignState(MatchState::FlowFromReadOnly);
NextAssignState(MatchState::FlowToReadWrite);
break;
case MatchState::FlowToWriteOnly:
NextAssignState(MatchState::FlowToWriteOnly);
NextMemState(MatchState::FlowToMemAliasWriteOnly);
break;
case MatchState::FlowToReadWrite:
NextAssignState(MatchState::FlowToReadWrite);
NextMemState(MatchState::FlowToMemAliasReadWrite);
break;
case MatchState::FlowToMemAliasWriteOnly:
NextAssignState(MatchState::FlowToWriteOnly);
break;
case MatchState::FlowToMemAliasReadWrite:
NextAssignState(MatchState::FlowToReadWrite);
break;
}
}
static void populateExternalRelations(
SmallVectorImpl<ExternalRelation> &ExtRelations, const Function &Fn,
const SmallVectorImpl<Value *> &RetVals, const ReachabilitySet &ReachSet) {
// If a function only returns one of its argument X, then X will be both an
// argument and a return value at the same time. This is an edge case that
// needs special handling here.
for (const auto &Arg : Fn.args()) {
if (is_contained(RetVals, &Arg)) {
auto ArgVal = InterfaceValue{Arg.getArgNo() + 1, 0};
auto RetVal = InterfaceValue{0, 0};
ExtRelations.push_back(ExternalRelation{ArgVal, RetVal, 0});
}
}
// Below is the core summary construction logic.
// A naive solution of adding only the value aliases that are parameters or
// return values in ReachSet to the summary won't work: It is possible that a
// parameter P is written into an intermediate value I, and the function
// subsequently returns *I. In that case, *I is does not value alias anything
// in ReachSet, and the naive solution will miss a summary edge from (P, 1) to
// (I, 1).
// To account for the aforementioned case, we need to check each non-parameter
// and non-return value for the possibility of acting as an intermediate.
// 'ValueMap' here records, for each value, which InterfaceValues read from or
// write into it. If both the read list and the write list of a given value
// are non-empty, we know that a particular value is an intermidate and we
// need to add summary edges from the writes to the reads.
DenseMap<Value *, ValueSummary> ValueMap;
for (const auto &OuterMapping : ReachSet.value_mappings()) {
if (auto Dst = getInterfaceValue(OuterMapping.first, RetVals)) {
for (const auto &InnerMapping : OuterMapping.second) {
// If Src is a param/return value, we get a same-level assignment.
if (auto Src = getInterfaceValue(InnerMapping.first, RetVals)) {
// This may happen if both Dst and Src are return values
if (*Dst == *Src)
continue;
if (hasReadOnlyState(InnerMapping.second))
ExtRelations.push_back(ExternalRelation{*Dst, *Src, UnknownOffset});
// No need to check for WriteOnly state, since ReachSet is symmetric
} else {
// If Src is not a param/return, add it to ValueMap
auto SrcIVal = InnerMapping.first;
if (hasReadOnlyState(InnerMapping.second))
ValueMap[SrcIVal.Val].FromRecords.push_back(
ValueSummary::Record{*Dst, SrcIVal.DerefLevel});
if (hasWriteOnlyState(InnerMapping.second))
ValueMap[SrcIVal.Val].ToRecords.push_back(
ValueSummary::Record{*Dst, SrcIVal.DerefLevel});
}
}
}
}
for (const auto &Mapping : ValueMap) {
for (const auto &FromRecord : Mapping.second.FromRecords) {
for (const auto &ToRecord : Mapping.second.ToRecords) {
auto ToLevel = ToRecord.DerefLevel;
auto FromLevel = FromRecord.DerefLevel;
// Same-level assignments should have already been processed by now
if (ToLevel == FromLevel)
continue;
auto SrcIndex = FromRecord.IValue.Index;
auto SrcLevel = FromRecord.IValue.DerefLevel;
auto DstIndex = ToRecord.IValue.Index;
auto DstLevel = ToRecord.IValue.DerefLevel;
if (ToLevel > FromLevel)
SrcLevel += ToLevel - FromLevel;
else
DstLevel += FromLevel - ToLevel;
ExtRelations.push_back(ExternalRelation{
InterfaceValue{SrcIndex, SrcLevel},
InterfaceValue{DstIndex, DstLevel}, UnknownOffset});
}
}
}
// Remove duplicates in ExtRelations
llvm::sort(ExtRelations.begin(), ExtRelations.end());
ExtRelations.erase(std::unique(ExtRelations.begin(), ExtRelations.end()),
ExtRelations.end());
}