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Dotty Repl OOM's on one-liner input

See original GitHub issue

Minimized code

scala> val I1: Int = 0 * * * 8 * 1 - 1 + 1 +

Output

Exception in thread "main" java.lang.OutOfMemoryError: GC overhead limit exceeded
	at scala.runtime.IntRef.create(IntRef.java:22)
	at dotty.tools.dotc.ast.Trees$Tree.treeSize(Trees.scala:182)
	at dotty.tools.dotc.ast.Trees$Tree.addSize$2(Trees.scala:184)
	at dotty.tools.dotc.ast.Trees$Tree.treeSize$$anonfun$1(Trees.scala:188)
	at dotty.tools.dotc.ast.Trees$Tree$$Lambda$786/1712635211.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:563)
	at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:561)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1279)
	at dotty.tools.dotc.ast.Trees$Tree.treeSize(Trees.scala:188)
	at dotty.tools.dotc.ast.Trees$Tree.addSize$2(Trees.scala:184)
	at dotty.tools.dotc.ast.Trees$Tree.addSize$1$$anonfun$1(Trees.scala:185)
	at dotty.tools.dotc.ast.Trees$Tree$$Lambda$853/2081703861.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.ast.Trees$Tree.addSize$2(Trees.scala:185)
	at dotty.tools.dotc.ast.Trees$Tree.treeSize$$anonfun$1(Trees.scala:188)
	at dotty.tools.dotc.ast.Trees$Tree$$Lambda$786/1712635211.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:563)
	at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:561)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1279)
	at dotty.tools.dotc.ast.Trees$Tree.treeSize(Trees.scala:188)
	at dotty.tools.dotc.ast.Trees$Tree.addSize$2(Trees.scala:184)
	at dotty.tools.dotc.ast.Trees$Tree.addSize$1$$anonfun$1(Trees.scala:185)
	at dotty.tools.dotc.ast.Trees$Tree$$Lambda$853/2081703861.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)

Expectation

REPL does not OOM.

For more information, see: https://github.com/lampepfl/dotty/issues/9344.

Issue Analytics

State:
Created 3 years ago
Reactions:1
Comments:5 (2 by maintainers)

Top GitHub Comments

2reactions

oderskycommented, Jan 4, 2021

@emilypi It’s fine. I had another look. The root cause is that errors get propagated too far. They should truncate implicit searches but don’t do it sufficiently well. The compiler is very lenient in that it does not report a type mismatch error if some participant is already erroneous. That’s good to cut down on noise. But it also means that implicit searches can get out of hand, because too much is eligible.

0reactions

emilypicommented, Jan 10, 2021

Thanks for looking into that @odersky

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