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| author | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-09-14 12:15:35 +0000 |
|---|---|---|
| committer | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-09-14 12:15:35 +0000 |
| commit | c0f03d837c9af04f404e800ce6fbeb65d1eac38a (patch) | |
| tree | 67d603a233023c8204c6d0665506af8e03fcf884 /src | |
| parent | 4c47e9435d8872a30f579ed451293d4772b95c31 (diff) | |
| download | scala-c0f03d837c9af04f404e800ce6fbeb65d1eac38a.tar.gz scala-c0f03d837c9af04f404e800ce6fbeb65d1eac38a.tar.bz2 scala-c0f03d837c9af04f404e800ce6fbeb65d1eac38a.zip | |
closes #3692: make instantiateTypeVar more care...
closes #3692: make instantiateTypeVar more careful so it does not change
T's info to >: T <: T.
review by odersky
Diffstat (limited to 'src')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Infer.scala | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala index d4979b0589..0c81bb3887 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala @@ -1250,6 +1250,8 @@ trait Infer { solve(tvars1, tvars1 map (_.origin.typeSymbol), tvars1 map (x => COVARIANT), false) } + // this is quite nasty: it destructively changes the info of the syms of e.g., method type params (see #3692, where the type param T's bounds were set to >: T <: T, so that parts looped) + // the changes are rolled back by restoreTypeBounds, but might be unintentially observed in the mean time def instantiateTypeVar(tvar: TypeVar) { val tparam = tvar.origin.typeSymbol if (false && @@ -1263,7 +1265,8 @@ trait Infer { } else { val (lo, hi) = instBounds(tvar) if (lo <:< hi) { - if (!((lo <:< tparam.info.bounds.lo) && (tparam.info.bounds.hi <:< hi))) { + if (!((lo <:< tparam.info.bounds.lo) && (tparam.info.bounds.hi <:< hi)) // bounds were improved + && tparam != lo.typeSymbolDirect && tparam != hi.typeSymbolDirect) { // don't create illegal cycles context.nextEnclosing(_.tree.isInstanceOf[CaseDef]).pushTypeBounds(tparam) tparam setInfo TypeBounds(lo, hi) if (settings.debug.value) log("new bounds of " + tparam + " = " + tparam.info) |