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author | Jason Zaugg <jzaugg@gmail.com> | 2013-05-07 23:29:02 +0200 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2014-11-14 22:19:49 +1000 |
commit | 5b8327b807c40cab867065cf695191a36c9210ee (patch) | |
tree | 8e3964382814439fe2436fa37941610179a92781 /src/compiler/scala/tools/nsc/typechecker/Typers.scala | |
parent | b431a4bd83d3bfb2b95d0426d2905b34ce1265ad (diff) | |
download | scala-5b8327b807c40cab867065cf695191a36c9210ee.tar.gz scala-5b8327b807c40cab867065cf695191a36c9210ee.tar.bz2 scala-5b8327b807c40cab867065cf695191a36c9210ee.zip |
SI-7459 Handle pattern binders used as prefixes in TypeTrees.
Match translation was incorrect for:
case t => new t.C
case D(t) => new d.C
We would end up with Types in TypeTrees referring to the wrong
symbols, e.g:
// t7459a.scala
((x0$1: this.LM) => {
case <synthetic> val x1: this.LM = x0$1;
case4(){
matchEnd3(new tttt.Node[Any]())
};
matchEnd3(x: Any){
x
}
Or:
// t7459b.scala
((x0$1: CC) => {
case <synthetic> val x1: CC = x0$1;
case4(){
if (x1.ne(null))
matchEnd3(new tttt.Node[Any]())
else
case5()
};
This commit:
- Changes `bindSubPats` to traverse types, as well as terms,
in search of references to bound symbols
- Changes `Substitution` to reuse `Tree#substituteSymbols` rather
than the home-brew substitution from `Tree`s to `Tree`s, if the
`to` trees are all `Ident`s
- extends `substIdentsForTrees` to substitute selections like
`x1.caseField` into types.
I had to dance around the awkward handling of "swatches" (exception
handlers that can be implemented with JVM native type switches) by
duplicating trees to avoid seeing the results of `substituteSymbols`
in `caseDefs` after we abandon that approach if we detect the
patterns are too complex late in the game.
I also had to add an escape hatch for the "type selection from
volatile type" check in the type checker. Without this, the
translation of `pos/t7459c.scala`:
case <synthetic> val x1: _$1 = (null: Test.Mirror[_]).universe;
case5(){
if (x1.isInstanceOf[Test.JavaUniverse])
{
<synthetic> val x2: _$1 with Test.JavaUniverse = (x1.asInstanceOf[_$1 with Test.JavaUniverse]: _$1 with Test.JavaUniverse);
matchEnd4({
val ju1: Test.JavaUniverse = x2;
val f: () => x2.Type = (() => (null: x2.TypeTag[Nothing]).tpe);
.. triggers that error at `x2.TypeTag`.
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/Typers.scala')
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 70acb03584..f93f8a781d 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -3727,8 +3727,12 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper case TypeRef(pre, sym, args) => if (sym.isAliasType && containsLocal(tp) && (tp.dealias ne tp)) apply(tp.dealias) else { - if (pre.isVolatile) - InferTypeWithVolatileTypeSelectionError(tree, pre) + if (pre.isVolatile) pre match { + case SingleType(_, sym) if sym.isSynthetic && isPastTyper => + debuglog(s"ignoring volatility of prefix in pattern matcher generated inferred type: $tp") // See pos/t7459c.scala + case _ => + InferTypeWithVolatileTypeSelectionError(tree, pre) + } mapOver(tp) } case _ => |