public Item confluence(List inItems, List itemKeys, Term node, FlowGraph graph) {
// if any predecessor is reachable, so is this one, and if any
// predecessor is normal reachable, and the edge key is not an
// exception edge key, then so is this one.
List l = this.filterItemsNonException(inItems, itemKeys);
for (Iterator i = l.iterator(); i.hasNext(); ) {
if (i.next() == DataFlowItem.REACHABLE) {
// this term is reachable via a non-exception edge
return DataFlowItem.REACHABLE;
}
}
// If we fall through to here, then there were
// no non-exception edges that were normally reachable.
// We now need to determine if this node is
// reachable via an exception edge key, or if
// it is not reachable at all.
for (Iterator i = inItems.iterator(); i.hasNext(); ) {
if (((DataFlowItem) i.next()).reachable) {
// this term is reachable, but only through an
// exception edge.
return DataFlowItem.REACHABLE_EX_ONLY;
}
}
return DataFlowItem.NOT_REACHABLE;
}
/**
* The confluence operator is essentially the union of all of the inItems. However, if two or more
* of the initCount maps from the inItems each have a MinMaxInitCounts entry for the same
* VarInstance, the conflict must be resolved, by using the minimum of all mins and the maximum of
* all maxs.
*/
public Item confluence(List inItems, Term node, FlowGraph graph) {
// Resolve any conflicts pairwise.
Iterator iter = inItems.iterator();
Map m = null;
while (iter.hasNext()) {
Item itm = (Item) iter.next();
if (itm == BOTTOM) continue;
if (m == null) {
m = new HashMap(((DataFlowItem) itm).initStatus);
} else {
Map n = ((DataFlowItem) itm).initStatus;
for (Iterator iter2 = n.entrySet().iterator(); iter2.hasNext(); ) {
Map.Entry entry = (Map.Entry) iter2.next();
VarInstance v = (VarInstance) entry.getKey();
MinMaxInitCount initCount1 = (MinMaxInitCount) m.get(v);
MinMaxInitCount initCount2 = (MinMaxInitCount) entry.getValue();
m.put(v, MinMaxInitCount.join(initCount1, initCount2));
}
}
}
if (m == null) return BOTTOM;
return new DataFlowItem(m);
}
/** Write the statement to an output file. */
public void prettyPrint(CodeWriter w, PrettyPrinter tr) {
w.write("for (");
w.begin(0);
if (inits != null) {
boolean first = true;
for (Iterator i = inits.iterator(); i.hasNext(); ) {
ForInit s = (ForInit) i.next();
printForInit(s, w, tr, first);
first = false;
if (i.hasNext()) {
w.write(",");
w.allowBreak(2, " ");
}
}
}
w.write(";");
w.allowBreak(0);
if (cond != null) {
printBlock(cond, w, tr);
}
w.write(";");
w.allowBreak(0);
if (iters != null) {
for (Iterator i = iters.iterator(); i.hasNext(); ) {
ForUpdate s = (ForUpdate) i.next();
printForUpdate(s, w, tr);
if (i.hasNext()) {
w.write(",");
w.allowBreak(2, " ");
}
}
}
w.end();
w.write(")");
printSubStmt(body, w, tr);
}
/**
* Insert the list of <code>newPasses</code> into <code>passes</code> immediately after the pass
* named <code>id</code>.
*/
public void afterPass(List passes, Pass.ID id, List newPasses) {
for (ListIterator i = passes.listIterator(); i.hasNext(); ) {
Pass p = (Pass) i.next();
if (p.id() == id) {
for (Iterator j = newPasses.iterator(); j.hasNext(); ) {
i.add(j.next());
}
return;
}
}
throw new InternalCompilerError("Pass " + id + " not found.");
}
/**
* Insert the list of <code>newPasses</code> into <code>passes</code> immediately before the pass
* named <code>id</code>.
*/
public void beforePass(List passes, Pass.ID id, List newPasses) {
for (ListIterator i = passes.listIterator(); i.hasNext(); ) {
Pass p = (Pass) i.next();
if (p.id() == id) {
// Backup one position.
i.previous();
for (Iterator j = newPasses.iterator(); j.hasNext(); ) {
i.add(j.next());
}
return;
}
}
throw new InternalCompilerError("Pass " + id + " not found.");
}
/**
* Replace the pass named <code>id</code> in <code>passes</code> with the list of <code>newPasses
* </code>.
*/
public void replacePass(List passes, Pass.ID id, List newPasses) {
for (ListIterator i = passes.listIterator(); i.hasNext(); ) {
Pass p = (Pass) i.next();
if (p.id() == id) {
if (p instanceof BarrierPass) {
throw new InternalCompilerError("Cannot replace a barrier pass.");
}
i.remove();
for (Iterator j = newPasses.iterator(); j.hasNext(); ) {
i.add(j.next());
}
return;
}
}
throw new InternalCompilerError("Pass " + id + " not found.");
}
/**
* Get the sub-list of passes for the job between passes <code>begin</code> and <code>end</code>,
* inclusive.
*/
public List passes(Job job, Pass.ID begin, Pass.ID end) {
List l = passes(job);
Pass p = null;
Iterator i = l.iterator();
while (i.hasNext()) {
p = (Pass) i.next();
if (begin == p.id()) break;
if (!(p instanceof BarrierPass)) i.remove();
}
while (p.id() != end && i.hasNext()) {
p = (Pass) i.next();
}
while (i.hasNext()) {
p = (Pass) i.next();
i.remove();
}
return l;
}
/** Type check the statement. */
public Node typeCheck(TypeChecker tc) throws SemanticException {
TypeSystem ts = tc.typeSystem();
// Check that all initializers have the same type.
// This should be enforced by the parser, but check again here,
// just to be sure.
Type t = null;
for (Iterator i = inits.iterator(); i.hasNext(); ) {
ForInit s = (ForInit) i.next();
if (s instanceof LocalDecl) {
LocalDecl d = (LocalDecl) s;
Type dt = d.type().type();
if (t == null) {
t = dt;
} else if (!t.equals(dt)) {
throw new InternalCompilerError(
"Local variable "
+ "declarations in a for loop initializer must all "
+ "be the same type, in this case "
+ t
+ ", not "
+ dt
+ ".",
d.position());
}
}
}
if (cond != null && !ts.isImplicitCastValid(cond.type(), ts.Boolean())) {
throw new SemanticException(
"The condition of a for statement must have boolean type.", cond.position());
}
return this;
}
/**
* Before running <code>Pass pass</code> on <code>SourceJob job</code> make sure that all
* appropriate scheduling invariants are satisfied, to ensure that all passes of other jobs that
* <code>job</code> depends on will have already been done.
*/
protected void enforceInvariants(Job job, Pass pass) throws CyclicDependencyException {
SourceJob srcJob = job.sourceJob();
if (srcJob == null) {
return;
}
BarrierPass lastBarrier = srcJob.lastBarrier();
if (lastBarrier != null) {
// make sure that _all_ dependent jobs have completed at least up to
// the last barrier (not just children).
//
// Ideally the invariant should be that only the source jobs that
// job _depends on_ should be brought up to the last barrier.
// This is work to be done in the future...
List allDependentSrcs = new ArrayList(srcJob.dependencies());
Iterator i = allDependentSrcs.iterator();
while (i.hasNext()) {
Source s = (Source) i.next();
Object o = jobs.get(s);
if (o == COMPLETED_JOB) continue;
if (o == null) {
throw new InternalCompilerError("Unknown source " + s);
}
SourceJob sj = (SourceJob) o;
if (sj.pending(lastBarrier.id())) {
// Make the job run up to the last barrier.
// We ignore the return result, since even if the job
// fails, we will keep on going and see
// how far we get...
if (Report.should_report(Report.frontend, 3)) {
Report.report(3, "Running " + sj + " to " + lastBarrier.id() + " for " + srcJob);
}
runToPass(sj, lastBarrier.id());
}
}
}
if (pass instanceof GlobalBarrierPass) {
// need to make sure that _all_ jobs have completed just up to
// this global barrier.
// If we hit a cyclic dependency, ignore it and run the other
// jobs up to that pass. Then try again to run the cyclic
// pass. If we hit the cycle again for the same job, stop.
LinkedList barrierWorklist = new LinkedList(jobs.values());
while (!barrierWorklist.isEmpty()) {
Object o = barrierWorklist.removeFirst();
if (o == COMPLETED_JOB) continue;
SourceJob sj = (SourceJob) o;
if (sj.completed(pass.id()) || sj.nextPass() == sj.passByID(pass.id())) {
// the source job has either done this global pass
// (which is possible if the job was loaded late in the
// game), or is right up to the global barrier.
continue;
}
// Make the job run up to just before the global barrier.
// We ignore the return result, since even if the job
// fails, we will keep on going and see
// how far we get...
Pass beforeGlobal = sj.getPreviousTo(pass.id());
if (Report.should_report(Report.frontend, 3)) {
Report.report(3, "Running " + sj + " to " + beforeGlobal.id() + " for " + srcJob);
}
// Don't use runToPass, since that catches the
// CyclicDependencyException that we should report
// back to the caller.
while (!sj.pendingPasses().isEmpty()) {
Pass p = (Pass) sj.pendingPasses().get(0);
runPass(sj, p);
if (p == beforeGlobal) {
break;
}
}
}
}
}