diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala | 42 |
1 files changed, 28 insertions, 14 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala index f7579ad249..87fe3fb3f6 100644 --- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala @@ -936,7 +936,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // the making of the trees /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// trait TreeMakers extends TypedSubstitution { self: CodegenCore => - def optimizeCases(prevBinder: Symbol, cases: List[List[TreeMaker]], pt: Type, unchecked: Boolean): (List[List[TreeMaker]], List[Tree]) = + def optimizeCases(prevBinder: Symbol, cases: List[List[TreeMaker]], pt: Type, supression: Suppression): (List[List[TreeMaker]], List[Tree]) = (cases, Nil) def emitSwitch(scrut: Tree, scrutSym: Symbol, cases: List[List[TreeMaker]], pt: Type, matchFailGenOverride: Option[Tree => Tree], unchecked: Boolean): Option[Tree] = @@ -1408,18 +1408,24 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def matchFailGen = (matchFailGenOverride orElse Some(CODE.MATCHERROR(_: Tree))) patmatDebug("combining cases: "+ (casesNoSubstOnly.map(_.mkString(" >> ")).mkString("{", "\n", "}"))) - val (unchecked, requireSwitch) = - if (settings.XnoPatmatAnalysis.value) (true, false) + val (suppression, requireSwitch): (Suppression, Boolean) = + if (settings.XnoPatmatAnalysis.value) (Suppression.NoSuppresion, false) else scrut match { - case Typed(_, tpt) => - (tpt.tpe hasAnnotation UncheckedClass, - // matches with two or fewer cases need not apply for switchiness (if-then-else will do) - treeInfo.isSwitchAnnotation(tpt.tpe) && casesNoSubstOnly.lengthCompare(2) > 0) + case Typed(tree, tpt) => + val suppressExhaustive = tpt.tpe hasAnnotation UncheckedClass + val supressUnreachable = tree match { + case Ident(name) if name startsWith nme.CHECK_IF_REFUTABLE_STRING => true // SI-7183 don't warn for withFilter's that turn out to be irrefutable. + case _ => false + } + val suppression = Suppression(suppressExhaustive, supressUnreachable) + // matches with two or fewer cases need not apply for switchiness (if-then-else will do) + val requireSwitch = treeInfo.isSwitchAnnotation(tpt.tpe) && casesNoSubstOnly.lengthCompare(2) > 0 + (suppression, requireSwitch) case _ => - (false, false) + (Suppression.NoSuppresion, false) } - emitSwitch(scrut, scrutSym, casesNoSubstOnly, pt, matchFailGenOverride, unchecked).getOrElse{ + emitSwitch(scrut, scrutSym, casesNoSubstOnly, pt, matchFailGenOverride, suppression.exhaustive).getOrElse{ if (requireSwitch) typer.context.unit.warning(scrut.pos, "could not emit switch for @switch annotated match") if (casesNoSubstOnly nonEmpty) { @@ -1436,7 +1442,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL }) None else matchFailGen - val (cases, toHoist) = optimizeCases(scrutSym, casesNoSubstOnly, pt, unchecked) + val (cases, toHoist) = optimizeCases(scrutSym, casesNoSubstOnly, pt, suppression) val matchRes = codegen.matcher(scrut, scrutSym, pt)(cases map combineExtractors, synthCatchAll) @@ -3831,11 +3837,13 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL with OptimizedCodegen with SymbolicMatchAnalysis with DPLLSolver { self: TreeMakers => - override def optimizeCases(prevBinder: Symbol, cases: List[List[TreeMaker]], pt: Type, unchecked: Boolean): (List[List[TreeMaker]], List[Tree]) = { - unreachableCase(prevBinder, cases, pt) foreach { caseIndex => - reportUnreachable(cases(caseIndex).last.pos) + override def optimizeCases(prevBinder: Symbol, cases: List[List[TreeMaker]], pt: Type, suppression: Suppression): (List[List[TreeMaker]], List[Tree]) = { + if (!suppression.unreachable) { + unreachableCase(prevBinder, cases, pt) foreach { caseIndex => + reportUnreachable(cases(caseIndex).last.pos) + } } - if (!unchecked) { + if (!suppression.exhaustive) { val counterExamples = exhaustive(prevBinder, cases, pt) if (counterExamples.nonEmpty) reportMissingCases(prevBinder.pos, counterExamples) @@ -3860,3 +3868,9 @@ object PatternMatchingStats { val patmatAnaExhaust = Statistics.newSubTimer (" of which in exhaustivity", patmatNanos) val patmatAnaReach = Statistics.newSubTimer (" of which in unreachability", patmatNanos) } + +final case class Suppression(exhaustive: Boolean, unreachable: Boolean) + +object Suppression { + val NoSuppresion = Suppression(false, false) +}
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