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author | phaller <hallerp@gmail.com> | 2012-05-25 17:36:19 +0200 |
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committer | phaller <philipp.haller@typesafe.com> | 2012-06-14 17:42:31 +0200 |
commit | 796024c7429a03e974a7d8e1dc5c80b84f82467d (patch) | |
tree | b4c900328a78ec7941530d1ecc27d544284febaf /src/compiler | |
parent | 4448e7a530626105776997fde04b4af76bf13de1 (diff) | |
download | scala-796024c7429a03e974a7d8e1dc5c80b84f82467d.tar.gz scala-796024c7429a03e974a7d8e1dc5c80b84f82467d.tar.bz2 scala-796024c7429a03e974a7d8e1dc5c80b84f82467d.zip |
CPS: enable return expressions in CPS code if they are in tail position
Adds a stack of context trees to AnnotationChecker(s). Here, it is used to
enforce that adaptAnnotations will only adapt the annotation of a return
expression if the expected type is a CPS type.
The remove-tail-return transform is reasonably general, covering cases such as
try-catch-finally. Moreover, an error is thrown if, in a CPS method, a return
is encountered which is not in a tail position such that it will be removed
subsequently.
Diffstat (limited to 'src/compiler')
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 2bdae4164a..7e4f50ecd7 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -3987,7 +3987,11 @@ trait Typers extends Modes with Adaptations with Tags { ReturnWithoutTypeError(tree, enclMethod.owner) } else { context.enclMethod.returnsSeen = true + //TODO: also pass enclMethod.tree, so that adaptAnnotations can check whether return is in tail position + pushAnnotationContext(tree) val expr1: Tree = typed(expr, EXPRmode | BYVALmode, restpt.tpe) + popAnnotationContext() + // Warn about returning a value if no value can be returned. if (restpt.tpe.typeSymbol == UnitClass) { // The typing in expr1 says expr is Unit (it has already been coerced if |