--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java Wed Jul 17 14:19:25 2013 +0100
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java Wed Jul 17 14:21:12 2013 +0100
@@ -461,9 +461,10 @@
}
finally {
mlistener.detach();
- if (mlistener.rounds == MAX_INCORPORATION_STEPS) {
+ if (incorporationCache.size() == MAX_INCORPORATION_STEPS) {
inferenceContext.rollback(saved_undet);
}
+ incorporationCache.clear();
}
}
//where
@@ -475,7 +476,6 @@
*/
class MultiUndetVarListener implements UndetVar.UndetVarListener {
- int rounds;
boolean changed;
List<Type> undetvars;
@@ -489,13 +489,12 @@
public void varChanged(UndetVar uv, Set<InferenceBound> ibs) {
//avoid non-termination
- if (rounds < MAX_INCORPORATION_STEPS) {
+ if (incorporationCache.size() < MAX_INCORPORATION_STEPS) {
changed = true;
}
}
void reset() {
- rounds++;
changed = false;
}
@@ -528,17 +527,17 @@
if (uv.inst != null) {
Type inst = uv.inst;
for (Type u : uv.getBounds(InferenceBound.UPPER)) {
- if (!infer.types.isSubtypeUnchecked(inst, inferenceContext.asFree(u), warn)) {
+ if (!isSubtype(inst, inferenceContext.asFree(u), warn, infer)) {
infer.reportBoundError(uv, BoundErrorKind.UPPER);
}
}
for (Type l : uv.getBounds(InferenceBound.LOWER)) {
- if (!infer.types.isSubtypeUnchecked(inferenceContext.asFree(l), inst, warn)) {
+ if (!isSubtype(inferenceContext.asFree(l), inst, warn, infer)) {
infer.reportBoundError(uv, BoundErrorKind.LOWER);
}
}
for (Type e : uv.getBounds(InferenceBound.EQ)) {
- if (!infer.types.isSameType(inst, inferenceContext.asFree(e))) {
+ if (!isSameType(inst, inferenceContext.asFree(e), infer)) {
infer.reportBoundError(uv, BoundErrorKind.EQ);
}
}
@@ -561,19 +560,19 @@
Type eq = null;
for (Type e : uv.getBounds(InferenceBound.EQ)) {
Assert.check(!inferenceContext.free(e));
- if (eq != null && !infer.types.isSameType(e, eq)) {
+ if (eq != null && !isSameType(e, eq, infer)) {
infer.reportBoundError(uv, BoundErrorKind.EQ);
}
eq = e;
for (Type l : uv.getBounds(InferenceBound.LOWER)) {
Assert.check(!inferenceContext.free(l));
- if (!infer.types.isSubtypeUnchecked(l, e, warn)) {
+ if (!isSubtype(l, e, warn, infer)) {
infer.reportBoundError(uv, BoundErrorKind.BAD_EQ_LOWER);
}
}
for (Type u : uv.getBounds(InferenceBound.UPPER)) {
if (inferenceContext.free(u)) continue;
- if (!infer.types.isSubtypeUnchecked(e, u, warn)) {
+ if (!isSubtype(e, u, warn, infer)) {
infer.reportBoundError(uv, BoundErrorKind.BAD_EQ_UPPER);
}
}
@@ -589,12 +588,12 @@
for (Type e : uv.getBounds(InferenceBound.EQ)) {
if (e.containsAny(inferenceContext.inferenceVars())) continue;
for (Type u : uv.getBounds(InferenceBound.UPPER)) {
- if (!infer.types.isSubtypeUnchecked(e, inferenceContext.asFree(u), warn)) {
+ if (!isSubtype(e, inferenceContext.asFree(u), warn, infer)) {
infer.reportBoundError(uv, BoundErrorKind.BAD_EQ_UPPER);
}
}
for (Type l : uv.getBounds(InferenceBound.LOWER)) {
- if (!infer.types.isSubtypeUnchecked(inferenceContext.asFree(l), e, warn)) {
+ if (!isSubtype(inferenceContext.asFree(l), e, warn, infer)) {
infer.reportBoundError(uv, BoundErrorKind.BAD_EQ_LOWER);
}
}
@@ -610,7 +609,7 @@
Infer infer = inferenceContext.infer();
for (Type b1 : uv.getBounds(InferenceBound.UPPER)) {
for (Type b2 : uv.getBounds(InferenceBound.LOWER)) {
- infer.types.isSubtypeUnchecked(inferenceContext.asFree(b2), inferenceContext.asFree(b1));
+ isSubtype(inferenceContext.asFree(b2), inferenceContext.asFree(b1), warn , infer);
}
}
}
@@ -624,7 +623,7 @@
Infer infer = inferenceContext.infer();
for (Type b1 : uv.getBounds(InferenceBound.UPPER)) {
for (Type b2 : uv.getBounds(InferenceBound.EQ)) {
- infer.types.isSubtypeUnchecked(inferenceContext.asFree(b2), inferenceContext.asFree(b1));
+ isSubtype(inferenceContext.asFree(b2), inferenceContext.asFree(b1), warn, infer);
}
}
}
@@ -638,7 +637,7 @@
Infer infer = inferenceContext.infer();
for (Type b1 : uv.getBounds(InferenceBound.EQ)) {
for (Type b2 : uv.getBounds(InferenceBound.LOWER)) {
- infer.types.isSubtypeUnchecked(inferenceContext.asFree(b2), inferenceContext.asFree(b1));
+ isSubtype(inferenceContext.asFree(b2), inferenceContext.asFree(b1), warn, infer);
}
}
}
@@ -653,7 +652,7 @@
for (Type b1 : uv.getBounds(InferenceBound.EQ)) {
for (Type b2 : uv.getBounds(InferenceBound.EQ)) {
if (b1 != b2) {
- infer.types.isSameType(inferenceContext.asFree(b2), inferenceContext.asFree(b1));
+ isSameType(inferenceContext.asFree(b2), inferenceContext.asFree(b1), infer);
}
}
}
@@ -672,14 +671,14 @@
if (uv2.isCaptured()) continue;
//alpha <: beta
//0. set beta :> alpha
- uv2.addBound(InferenceBound.LOWER, uv, infer.types);
+ addBound(InferenceBound.LOWER, uv2, inferenceContext.asInstType(uv.qtype), infer);
//1. copy alpha's lower to beta's
for (Type l : uv.getBounds(InferenceBound.LOWER)) {
- uv2.addBound(InferenceBound.LOWER, inferenceContext.asInstType(l), infer.types);
+ addBound(InferenceBound.LOWER, uv2, inferenceContext.asInstType(l), infer);
}
//2. copy beta's upper to alpha's
for (Type u : uv2.getBounds(InferenceBound.UPPER)) {
- uv.addBound(InferenceBound.UPPER, inferenceContext.asInstType(u), infer.types);
+ addBound(InferenceBound.UPPER, uv, inferenceContext.asInstType(u), infer);
}
}
}
@@ -698,14 +697,14 @@
if (uv2.isCaptured()) continue;
//alpha :> beta
//0. set beta <: alpha
- uv2.addBound(InferenceBound.UPPER, uv, infer.types);
+ addBound(InferenceBound.UPPER, uv2, inferenceContext.asInstType(uv.qtype), infer);
//1. copy alpha's upper to beta's
for (Type u : uv.getBounds(InferenceBound.UPPER)) {
- uv2.addBound(InferenceBound.UPPER, inferenceContext.asInstType(u), infer.types);
+ addBound(InferenceBound.UPPER, uv2, inferenceContext.asInstType(u), infer);
}
//2. copy beta's lower to alpha's
for (Type l : uv2.getBounds(InferenceBound.LOWER)) {
- uv.addBound(InferenceBound.LOWER, inferenceContext.asInstType(l), infer.types);
+ addBound(InferenceBound.LOWER, uv, inferenceContext.asInstType(l), infer);
}
}
}
@@ -724,12 +723,12 @@
if (uv2.isCaptured()) continue;
//alpha == beta
//0. set beta == alpha
- uv2.addBound(InferenceBound.EQ, uv, infer.types);
+ addBound(InferenceBound.EQ, uv2, inferenceContext.asInstType(uv.qtype), infer);
//1. copy all alpha's bounds to beta's
for (InferenceBound ib : InferenceBound.values()) {
for (Type b2 : uv.getBounds(ib)) {
if (b2 != uv2) {
- uv2.addBound(ib, inferenceContext.asInstType(b2), infer.types);
+ addBound(ib, uv2, inferenceContext.asInstType(b2), infer);
}
}
}
@@ -737,7 +736,7 @@
for (InferenceBound ib : InferenceBound.values()) {
for (Type b2 : uv2.getBounds(ib)) {
if (b2 != uv) {
- uv.addBound(ib, inferenceContext.asInstType(b2), infer.types);
+ addBound(ib, uv, inferenceContext.asInstType(b2), infer);
}
}
}
@@ -751,6 +750,41 @@
boolean accepts(UndetVar uv, InferenceContext inferenceContext) {
return !uv.isCaptured();
}
+
+ boolean isSubtype(Type s, Type t, Warner warn, Infer infer) {
+ return doIncorporationOp(IncorporationBinaryOpKind.IS_SUBTYPE, s, t, warn, infer);
+ }
+
+ boolean isSameType(Type s, Type t, Infer infer) {
+ return doIncorporationOp(IncorporationBinaryOpKind.IS_SAME_TYPE, s, t, null, infer);
+ }
+
+ void addBound(InferenceBound ib, UndetVar uv, Type b, Infer infer) {
+ doIncorporationOp(opFor(ib), uv, b, null, infer);
+ }
+
+ IncorporationBinaryOpKind opFor(InferenceBound boundKind) {
+ switch (boundKind) {
+ case EQ:
+ return IncorporationBinaryOpKind.ADD_EQ_BOUND;
+ case LOWER:
+ return IncorporationBinaryOpKind.ADD_LOWER_BOUND;
+ case UPPER:
+ return IncorporationBinaryOpKind.ADD_UPPER_BOUND;
+ default:
+ Assert.error("Can't get here!");
+ return null;
+ }
+ }
+
+ boolean doIncorporationOp(IncorporationBinaryOpKind opKind, Type op1, Type op2, Warner warn, Infer infer) {
+ IncorporationBinaryOp newOp = infer.new IncorporationBinaryOp(opKind, op1, op2);
+ Boolean res = infer.incorporationCache.get(newOp);
+ if (res == null) {
+ infer.incorporationCache.put(newOp, res = newOp.apply(warn));
+ }
+ return res;
+ }
}
/** incorporation steps to be executed when running in legacy mode */
@@ -761,6 +795,102 @@
EnumSet.complementOf(EnumSet.of(IncorporationStep.EQ_CHECK_LEGACY));
/**
+ * Three kinds of basic operation are supported as part of an incorporation step:
+ * (i) subtype check, (ii) same type check and (iii) bound addition (either
+ * upper/lower/eq bound).
+ */
+ enum IncorporationBinaryOpKind {
+ IS_SUBTYPE() {
+ @Override
+ boolean apply(Type op1, Type op2, Warner warn, Types types) {
+ return types.isSubtypeUnchecked(op1, op2, warn);
+ }
+ },
+ IS_SAME_TYPE() {
+ @Override
+ boolean apply(Type op1, Type op2, Warner warn, Types types) {
+ return types.isSameType(op1, op2);
+ }
+ },
+ ADD_UPPER_BOUND() {
+ @Override
+ boolean apply(Type op1, Type op2, Warner warn, Types types) {
+ UndetVar uv = (UndetVar)op1;
+ uv.addBound(InferenceBound.UPPER, op2, types);
+ return true;
+ }
+ },
+ ADD_LOWER_BOUND() {
+ @Override
+ boolean apply(Type op1, Type op2, Warner warn, Types types) {
+ UndetVar uv = (UndetVar)op1;
+ uv.addBound(InferenceBound.LOWER, op2, types);
+ return true;
+ }
+ },
+ ADD_EQ_BOUND() {
+ @Override
+ boolean apply(Type op1, Type op2, Warner warn, Types types) {
+ UndetVar uv = (UndetVar)op1;
+ uv.addBound(InferenceBound.EQ, op2, types);
+ return true;
+ }
+ };
+
+ abstract boolean apply(Type op1, Type op2, Warner warn, Types types);
+ }
+
+ /**
+ * This class encapsulates a basic incorporation operation; incorporation
+ * operations takes two type operands and a kind. Each operation performed
+ * during an incorporation round is stored in a cache, so that operations
+ * are not executed unnecessarily (which would potentially lead to adding
+ * same bounds over and over).
+ */
+ class IncorporationBinaryOp {
+
+ IncorporationBinaryOpKind opKind;
+ Type op1;
+ Type op2;
+
+ IncorporationBinaryOp(IncorporationBinaryOpKind opKind, Type op1, Type op2) {
+ this.opKind = opKind;
+ this.op1 = op1;
+ this.op2 = op2;
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (!(o instanceof IncorporationBinaryOp)) {
+ return false;
+ } else {
+ IncorporationBinaryOp that = (IncorporationBinaryOp)o;
+ return opKind == that.opKind &&
+ types.isSameType(op1, that.op1, true) &&
+ types.isSameType(op2, that.op2, true);
+ }
+ }
+
+ @Override
+ public int hashCode() {
+ int result = opKind.hashCode();
+ result *= 127;
+ result += types.hashCode(op1);
+ result *= 127;
+ result += types.hashCode(op2);
+ return result;
+ }
+
+ boolean apply(Warner warn) {
+ return opKind.apply(op1, op2, warn, types);
+ }
+ }
+
+ /** an incorporation cache keeps track of all executed incorporation-related operations */
+ Map<IncorporationBinaryOp, Boolean> incorporationCache =
+ new HashMap<IncorporationBinaryOp, Boolean>();
+
+ /**
* Make sure that the upper bounds we got so far lead to a solvable inference
* variable by making sure that a glb exists.
*/
@@ -895,6 +1025,41 @@
Assert.check(!g.nodes.isEmpty(), "No nodes to solve!");
return g.nodes.get(0);
}
+
+ boolean isSubtype(Type s, Type t, Warner warn, Infer infer) {
+ return doIncorporationOp(IncorporationBinaryOpKind.IS_SUBTYPE, s, t, warn, infer);
+ }
+
+ boolean isSameType(Type s, Type t, Infer infer) {
+ return doIncorporationOp(IncorporationBinaryOpKind.IS_SAME_TYPE, s, t, null, infer);
+ }
+
+ void addBound(InferenceBound ib, UndetVar uv, Type b, Infer infer) {
+ doIncorporationOp(opFor(ib), uv, b, null, infer);
+ }
+
+ IncorporationBinaryOpKind opFor(InferenceBound boundKind) {
+ switch (boundKind) {
+ case EQ:
+ return IncorporationBinaryOpKind.ADD_EQ_BOUND;
+ case LOWER:
+ return IncorporationBinaryOpKind.ADD_LOWER_BOUND;
+ case UPPER:
+ return IncorporationBinaryOpKind.ADD_UPPER_BOUND;
+ default:
+ Assert.error("Can't get here!");
+ return null;
+ }
+ }
+
+ boolean doIncorporationOp(IncorporationBinaryOpKind opKind, Type op1, Type op2, Warner warn, Infer infer) {
+ IncorporationBinaryOp newOp = infer.new IncorporationBinaryOp(opKind, op1, op2);
+ Boolean res = infer.incorporationCache.get(newOp);
+ if (res == null) {
+ infer.incorporationCache.put(newOp, res = newOp.apply(warn));
+ }
+ return res;
+ }
}
/**