protected Node checkReachability(Term n) throws SemanticException {
FlowGraph g = currentFlowGraph();
if (g != null) {
Collection peers = g.peers(n);
if (peers != null && !peers.isEmpty()) {
boolean isInitializer = (n instanceof Initializer);
for (Iterator iter = peers.iterator(); iter.hasNext(); ) {
FlowGraph.Peer p = (FlowGraph.Peer) iter.next();
// the peer is reachable if at least one of its out items
// is reachable. This would cover all cases, except that some
// peers may have no successors (e.g. peers that throw an
// an exception that is not caught by the method). So we need
// to also check the inItem.
if (p.inItem() != null) {
DataFlowItem dfi = (DataFlowItem) p.inItem();
// there will only be one peer for an initializer,
// as it cannot occur in a finally block.
if (isInitializer && !dfi.normalReachable) {
throw new SemanticException(
"Initializers must be able to complete normally.", n.position());
}
if (dfi.reachable) {
return n.reachable(true);
}
}
if (p.outItems != null) {
for (Iterator k = p.outItems.values().iterator(); k.hasNext(); ) {
DataFlowItem item = (DataFlowItem) k.next();
if (item != null && item.reachable) {
// n is reachable.
return n.reachable(true);
}
}
}
}
// if we fall through to here, then no peer for n was reachable.
n = n.reachable(false);
// Compound statements are allowed to be unreachable
// (e.g., "{ // return; }" or "while (true) S"). If a compound
// statement is truly unreachable, one of its sub-statements will
// be also and we will report an error there.
if ((n instanceof Block && ((Block) n).statements().isEmpty())
|| (n instanceof Stmt && !(n instanceof CompoundStmt))) {
throw new SemanticException("Unreachable statement.", n.position());
}
}
}
return n;
}
private Node translateSJInbranch(SJInbranch ib, QQ qq) {
StringBuilder translation = new StringBuilder("{ ");
Collection<Object> mapping = new LinkedList<Object>();
String labVar = UniqueID.newID(SJ_INBRANCH_LABEL_FIELD_PREFIX);
translation.append("%T %s = %E; ");
mapping.add(qq.parseType(SJ_LABEL_CLASS));
mapping.add(labVar);
mapping.add(ib.inlabel());
for (Iterator<SJInbranchCase> i = ib.branchCases().iterator(); i.hasNext(); ) {
SJInbranchCase ibc = i.next();
translation.append("if (%s.equals(%E)) { %LS } ");
mapping.add(labVar);
mapping.add(sjnf.StringLit(ib.position(), ibc.label().labelValue()));
mapping.add(ibc.statements());
if (i.hasNext()) {
translation.append("else ");
}
}
translation.append("else { throw new SJIOException(\"Unexpected inbranch label: \" + %s); }");
mapping.add(labVar);
// FIXME: need a final else case to better handle, if runtime monitoring is disabled,
// non-sj-compatibility mode and in case of malicious peers.
translation.append('}');
return qq.parseStmt(translation.toString(), mapping.toArray());
}
protected Node checkReachability(Term n) {
FlowGraph g = currentFlowGraph();
if (g != null) {
Collection<FlowGraph.Peer> peers = g.peers(n, Term.EXIT);
if (peers != null && !peers.isEmpty()) {
boolean isInitializer = (n instanceof Initializer);
for (FlowGraph.Peer p : peers) {
// the peer is reachable if at least one of its out items
// is reachable. This would cover all cases, except that some
// peers may have no successors (e.g. peers that throw an
// an exception that is not caught by the method). So we need
// to also check the inItem.
if (p.inItem() != null) {
DataFlowItem dfi = (DataFlowItem) p.inItem();
// there will only be one peer for an initializer,
// as it cannot occur in a finally block.
if (isInitializer && !dfi.normalReachable) {
reportError(new Errors.InitializersMustCompleteNormally(n.position()));
}
if (dfi.reachable) {
return n.reachable(true);
}
}
if (p.outItems != null) {
for (Item v : p.outItems.values()) {
DataFlowItem item = (DataFlowItem) v;
if (item != null && item.reachable) {
// n is reachable.
return n.reachable(true);
}
}
}
}
// if we fall through to here, then no peer for n was reachable.
n = n.reachable(false);
}
}
return n;
}
// FIXME: does not integrate with recursive session method calls: recursionEnter/Exit and also
// recurse do not match the control flow of recursive calls, and hence runtime type monitoring
// does not work.
private Node translateSJRecursion(SJRecursion r, QQ qq)
// recursionEnter inserted by node factory, but translation is finished here..
{
SJSessionOperationExt soe = getSJSessionOperationExt(r);
Position pos = r.position();
Collection<Object> mapping = new LinkedList<Object>();
String bname = getRecursionBooleanName(soe.targetNames(), r.label());
mapping.add(bname);
mapping.add(bname);
String translation = "for (boolean %s = true; %s; ) { }";
For f = (For) qq.parseStmt(translation, mapping.toArray());
mapping.clear();
r = (SJRecursion) r.inits(f.inits());
r = (SJRecursion) r.cond(f.cond());
List stmts = new LinkedList();
stmts.addAll(r.body().statements());
translation = "%s = %E;";
mapping.add(bname);
mapping.add(((Eval) stmts.remove(0)).expr()); // Factor out constant.
Eval e = (Eval) qq.parseStmt(translation, mapping.toArray());
stmts.add(0, e);
r = (SJRecursion) r.body(sjnf.Block(pos, stmts));
/*// Appending the recursion-exit hook. // Disabled to support delegation from within recursion scopes (socket will be null on recursion-exit).
List<Local> targets = new LinkedList<Local>(); // FIXME: should be SJLocalSockets.
for (String sjname : soe.targetNames()) // Unicast optimisation for SJRecursionExit is done within the NodeFactory method - this pass comes after SJUnicastOptimiser.
{
targets.add(sjnf.Local(pos, sjnf.Id(pos, sjname))); // Would it be bad to instead alias the recursionEnter targets?
}
SJRecursionExit re = sjnf.SJRecursionExit(pos, targets); // Problem: the sockets argument array is not yet filled (for other (internal) basic operations, this was done earlier by SJSessionOperationParser)...
re = (SJRecursionExit) SJVariableParser.parseSJSessionOperation(this, re); // ...Current fix: use those routines form those earlier passes.
re = (SJRecursionExit) SJSessionOperationParser.fixSJBasicOperationArguments(this, re);*/
// return sjnf.Block(pos, r, sjnf.Eval(pos, re));
return sjnf.Block(pos, r);
}