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[bport] Revert to fix false positive reachability warnings #14104

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Merged
merged 1 commit into from
Dec 14, 2021
Merged

[bport] Revert to fix false positive reachability warnings #14104

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5 changes: 3 additions & 2 deletions compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -953,8 +953,9 @@ class SpaceEngine(using Context) extends SpaceLogic {
if prev == Empty && covered == Empty then // defer until a case is reachable
deferred ::= pat
else {
for (pat <- deferred.reverseIterator)
report.warning(MatchCaseUnreachable(), pat.srcPos)
// FIXME: These should be emitted, but reverted for i13931
//for (pat <- deferred.reverseIterator)
// report.warning(MatchCaseUnreachable(), pat.srcPos)
if pat != EmptyTree // rethrow case of catch uses EmptyTree
&& isSubspace(covered, prev)
then {
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12 changes: 6 additions & 6 deletions tests/neg-custom-args/fatal-warnings/i8711.check
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@@ -1,8 +1,8 @@
-- [E030] Match case Unreachable Error: tests/neg-custom-args/fatal-warnings/i8711.scala:7:9 ---------------------------
-- Error: tests/neg-custom-args/fatal-warnings/i8711.scala:7:9 ---------------------------------------------------------
7 | case x: B => x // error: this case is unreachable since class A is not a subclass of class B
| ^^^^
| Unreachable case
-- [E030] Match case Unreachable Error: tests/neg-custom-args/fatal-warnings/i8711.scala:12:9 --------------------------
| ^
| this case is unreachable since type A and class B are unrelated
-- Error: tests/neg-custom-args/fatal-warnings/i8711.scala:12:9 --------------------------------------------------------
12 | case x: C => x // error
| ^^^^
| Unreachable case
| ^
| this case is unreachable since type A | B and class C are unrelated
1 change: 0 additions & 1 deletion tests/patmat/i13485.check
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@@ -1,2 +1 @@
11: Match case Unreachable
16: Match case Unreachable
2 changes: 1 addition & 1 deletion tests/patmat/i13485.scala
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Expand Up @@ -8,7 +8,7 @@ sealed trait Foo
class Bar

def test1(bar: Bar) = bar match
case _: Foo => 1
case _: Foo => 1 // FIXME: this is unreachable, but reverted for i13931
case _: Bar => 2

def test2(bar: Bar) = bar match
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4 changes: 4 additions & 0 deletions tests/patmat/i13931.scala
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@@ -0,0 +1,4 @@
class Test:
def test = Vector() match
case Seq() => println("empty")
case _ => println("non-empty")