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author | Jason Zaugg <jzaugg@gmail.com> | 2012-05-26 22:49:12 +0200 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2012-05-27 12:18:44 +0200 |
commit | c82bc67737a31f2a639172e677cafdefe8fdbf4e (patch) | |
tree | 6da5069e6c92b72e36d5118cb79424f511d1fe2b | |
parent | 688c558b0257636f8f46240616b8b3d448847a47 (diff) | |
download | scala-c82bc67737a31f2a639172e677cafdefe8fdbf4e.tar.gz scala-c82bc67737a31f2a639172e677cafdefe8fdbf4e.tar.bz2 scala-c82bc67737a31f2a639172e677cafdefe8fdbf4e.zip |
Fix a NSDNHAO in extension methods.
A bridge method, created when we override a method from
a superclass and refine the return type, was appearing
as an overloaded alternative. (`erasure` doesn't create
new scopes, so the bridges it builds are visible at
earlier phases.)
The problem was masked when compiling with specialization,
which *does* create a new scope, shielding the code in
question from the artefacts of erasure.
To fix the problem, we filter out bridge methods from
the overloaded alternatives returned by `.decl`, as would
happen internally in `.member`.
4 files changed, 32 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala b/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala index 007457ef7b..8556cc9ddc 100644 --- a/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala +++ b/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala @@ -44,8 +44,18 @@ abstract class ExtensionMethods extends Transform with TypingTransformers { * in `extensionMethod` if the first name has the wrong type. We thereby gain a level of insensitivity * of how overloaded types are ordered between phases and picklings. */ - private def extensionNames(imeth: Symbol): Stream[Name] = - imeth.owner.info.decl(imeth.name).tpe match { + private def extensionNames(imeth: Symbol): Stream[Name] = { + val decl = imeth.owner.info.decl(imeth.name) + + // Bridge generation is done at phase `erasure`, but new scopes are only generated + // for the phase after that. So bridges are visible in earlier phases. + // + // `info.member(imeth.name)` filters these out, but we need to use `decl` + // to restrict ourselves to members defined in the current class, so we + // must do the filtering here. + val declTypeNoBridge = decl.filter(sym => !sym.isBridge).tpe + + declTypeNoBridge match { case OverloadedType(_, alts) => val index = alts indexOf imeth assert(index >= 0, alts+" does not contain "+imeth) @@ -55,6 +65,7 @@ abstract class ExtensionMethods extends Transform with TypingTransformers { assert(tpe != NoType, imeth.name+" not found in "+imeth.owner+"'s decls: "+imeth.owner.info.decls) Stream(newTermName("extension$"+imeth.name)) } + } /** Return the extension method that corresponds to given instance method `meth`. */ diff --git a/test/files/pos/value-class-override-no-spec.flags b/test/files/pos/value-class-override-no-spec.flags new file mode 100644 index 0000000000..a7e64e4f0c --- /dev/null +++ b/test/files/pos/value-class-override-no-spec.flags @@ -0,0 +1 @@ +-no-specialization
\ No newline at end of file diff --git a/test/files/pos/value-class-override-no-spec.scala b/test/files/pos/value-class-override-no-spec.scala new file mode 100644 index 0000000000..79de5d9305 --- /dev/null +++ b/test/files/pos/value-class-override-no-spec.scala @@ -0,0 +1,9 @@ +// There are two versions of this tests: one with and one without specialization. +// The bug was only exposed *without* specialization. +trait T extends Any { + def x: Any +} + +final class StringOps(val repr0: String) extends AnyVal with T { + def x = () +} diff --git a/test/files/pos/value-class-override-spec.scala b/test/files/pos/value-class-override-spec.scala new file mode 100644 index 0000000000..79de5d9305 --- /dev/null +++ b/test/files/pos/value-class-override-spec.scala @@ -0,0 +1,9 @@ +// There are two versions of this tests: one with and one without specialization. +// The bug was only exposed *without* specialization. +trait T extends Any { + def x: Any +} + +final class StringOps(val repr0: String) extends AnyVal with T { + def x = () +} |