From 62d97d7f110894a0c2f36b1ed9dd7ad59c0115fa Mon Sep 17 00:00:00 2001 From: Adriaan Moors Date: Tue, 29 Mar 2016 19:25:06 -0700 Subject: LMF cannot run trait's "initializer" (constructor) Thus, rule out traits that have a constructor (which we use as a proxy for having potentially side-effecting statements), and create an anonymous subclass for them at compile time. --- src/compiler/scala/tools/nsc/transform/Erasure.scala | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src/compiler') diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index cdf3e18b5a..ebb55afca9 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -1213,6 +1213,10 @@ abstract class Erasure extends AddInterfaces // When we delay sam expansion until after explicit outer & lambda lift, we could decide there whether // to expand sam at compile time or use LMF, and this implementation restriction could be lifted. sym.isStatic && + // HACK: this is to rule out traits with an effectful initializer. + // The constructor only exists if the trait's template has statements. + // Sadly, we can't be more precise without access to the tree that defines the SAM's owner. + !sym.primaryConstructor.exists && (sym.isInterface || sym.info.decls.forall(mem => mem.isMethod || mem.isType)) // TODO OPT: && {sym setFlag INTERFACE; true}) // we still need to check our ancestors even if the INTERFACE flag is set, as it doesn't take inheritance into account -- cgit v1.2.3