bool
sortVerticesByAddress(const ControlFlowGraph::ConstVertexIterator &a,
const ControlFlowGraph::ConstVertexIterator &b) {
const CfgVertex &av = a->value();
const CfgVertex &bv = b->value();
if (av.type() != bv.type() || av.type() != V_BASIC_BLOCK)
return av.type() < bv.type();
return av.address() < bv.address();
}
CfgConstEdgeSet
findCallReturnEdges(const ControlFlowGraph::ConstVertexIterator &callSite) {
CfgConstEdgeSet retval;
for (ControlFlowGraph::ConstEdgeIterator ei=callSite->outEdges().begin(); ei!=callSite->outEdges().end(); ++ei) {
if (ei->value().type() == E_CALL_RETURN)
retval.insert(ei);
}
return retval;
}
Sawyer::Optional<bool>
Partitioner::basicBlockOptionalMayReturn(const ControlFlowGraph::ConstVertexIterator &start) const {
ASSERT_require(start != cfg_.vertices().end());
// Return a cached value if there is one
if (start->value().type() == V_BASIC_BLOCK) {
if (BasicBlock::Ptr bblock = start->value().bblock()) {
bool b;
if (bblock->mayReturn().getOptional().assignTo(b))
return b;
}
}
// Do the hard work
std::vector<MayReturnVertexInfo> vertexInfo(cfg_.nVertices());
return basicBlockOptionalMayReturn(start, vertexInfo);
}
// Internal: Run the may-return analysis on the callees and return true if any of them have a positive or indeterminate
// may-return property.
boost::logic::tribool
Partitioner::mayReturnDoesCalleeReturn(const ControlFlowGraph::ConstVertexIterator &caller,
std::vector<MayReturnVertexInfo> &vertexInfo) const {
ASSERT_require(caller != cfg_.vertices().end());
if (!vertexInfo[caller->id()].processedCallees) {
vertexInfo[caller->id()].anyCalleesReturn = false;
bool hasPositiveCallee = false, hasIndeterminateCallee = false;
BOOST_FOREACH (const ControlFlowGraph::Edge &edge, caller->outEdges()) {
if (edge.value().type() == E_FUNCTION_CALL) {
ControlFlowGraph::ConstVertexIterator callee = edge.target();
bool mayReturn = false;
if (!basicBlockOptionalMayReturn(callee, vertexInfo).assignTo(mayReturn)) {
hasIndeterminateCallee = true;
} else if (mayReturn) {
hasPositiveCallee = true;
break;
}
}
}
if (hasPositiveCallee) {
vertexInfo[caller->id()].anyCalleesReturn = true;
} else if (hasIndeterminateCallee) {
vertexInfo[caller->id()].anyCalleesReturn = boost::logic::indeterminate;
}
vertexInfo[caller->id()].processedCallees = true;
}
