diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala | 130 |
1 files changed, 37 insertions, 93 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala index f7579ad249..edece3fb67 100644 --- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala @@ -37,13 +37,11 @@ import scala.reflect.internal.Types * - recover exhaustivity/unreachability of user-defined extractors by partitioning the types they match on using an HList or similar type-level structure */ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL { // self: Analyzer => - import Statistics._ import PatternMatchingStats._ val global: Global // need to repeat here because otherwise last mixin defines global as // SymbolTable. If we had DOT this would not be an issue import global._ // the global environment - import definitions._ // standard classes and methods val phaseName: String = "patmat" @@ -109,6 +107,13 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL import definitions._ import analyzer._ //Typer + // 2.10/2.11 compatibility + protected final def dealiasWiden(tp: Type) = tp.dealias // 2.11: dealiasWiden + protected final def mkTRUE = CODE.TRUE_typed // 2.11: CODE.TRUE + protected final def mkFALSE = CODE.FALSE_typed // 2.11: CODE.FALSE + protected final def hasStableSymbol(p: Tree) = p.hasSymbol && p.symbol.isStable // 2.11: p.hasSymbolField && p.symbol.isStable + protected final def devWarning(str: String) = debugwarn(str) // 2.11: omit + object vpmName { val one = newTermName("one") val drop = newTermName("drop") @@ -189,7 +194,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL trait MatchTranslation extends MatchMonadInterface { self: TreeMakers with CodegenCore => import typer.{typed, context, silent, reallyExists} - // import typer.infer.containsUnchecked // Why is it so difficult to say "here's a name and a context, give me any // matching symbol in scope" ? I am sure this code is wrong, but attempts to @@ -279,7 +283,9 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // we don't transform after uncurry // (that would require more sophistication when generating trees, // and the only place that emits Matches after typers is for exception handling anyway) - if(phase.id >= currentRun.uncurryPhase.id) debugwarn("running translateMatch at "+ phase +" on "+ selector +" match "+ cases) + if (phase.id >= currentRun.uncurryPhase.id) + devWarning(s"running translateMatch past uncurry (at $phase) on $selector match $cases") + patmatDebug("translating "+ cases.mkString("{", "\n", "}")) val start = if (Statistics.canEnable) Statistics.startTimer(patmatNanos) else null @@ -300,7 +306,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL val pt = repeatedToSeq(ptUnCPS) // val packedPt = repeatedToSeq(typer.packedType(match_, context.owner)) - val selectorSym = freshSym(selector.pos, pureType(selectorTp)) setFlag treeInfo.SYNTH_CASE_FLAGS // pt = Any* occurs when compiling test/files/pos/annotDepMethType.scala with -Xexperimental @@ -488,7 +493,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL **/ // must treat Typed and Bind together -- we need to know the patBinder of the Bind pattern to get at the actual type case MaybeBoundTyped(subPatBinder, pt) => - val next = glb(List(patBinder.info.widen, pt)).normalize + val next = glb(List(dealiasWiden(patBinder.info), pt)).normalize // a typed pattern never has any subtrees noFurtherSubPats(TypeTestTreeMaker(subPatBinder, patBinder, pt, next)(pos)) @@ -561,59 +566,8 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// object ExtractorCall { - def apply(unfun: Tree, args: List[Tree]): ExtractorCall = new ExtractorCallRegular(unfun, args) - - def fromCaseClass(fun: Tree, args: List[Tree]): Option[ExtractorCall] = Some(new ExtractorCallProd(fun, args)) - - // THE PRINCIPLED SLOW PATH -- NOT USED - // generate a call to the (synthetically generated) extractor of a case class - // NOTE: it's an apply, not a select, since in general an extractor call may have multiple argument lists (including an implicit one) - // that we need to preserve, so we supply the scrutinee as Ident(nme.SELECTOR_DUMMY), - // and replace that dummy by a reference to the actual binder in translateExtractorPattern - def fromCaseClassUnapply(fun: Tree, args: List[Tree]): Option[ExtractorCall] = { - // TODO: can we rework the typer so we don't have to do all this twice? - // undo rewrite performed in (5) of adapt - val orig = fun match {case tpt: TypeTree => tpt.original case _ => fun} - val origSym = orig.symbol - val extractor = unapplyMember(origSym.filter(sym => reallyExists(unapplyMember(sym.tpe))).tpe) - - if((fun.tpe eq null) || fun.tpe.isError || (extractor eq NoSymbol)) { - None - } else { - // this is a tricky balance: pos/t602.scala, pos/sudoku.scala, run/virtpatmat_alts.scala must all be happy - // bypass typing at own risk: val extractorCall = Select(orig, extractor) setType caseClassApplyToUnapplyTp(fun.tpe) - // can't always infer type arguments (pos/t602): - /* case class Span[K <: Ordered[K]](low: Option[K]) { - override def equals(x: Any): Boolean = x match { - case Span((low0 @ _)) if low0 equals low => true - } - }*/ - // so... leave undetermined type params floating around if we have to - // (if we don't infer types, uninstantiated type params show up later: pos/sudoku.scala) - // (see also run/virtpatmat_alts.scala) - val savedUndets = context.undetparams - val extractorCall = try { - context.undetparams = Nil - silent(_.typed(Apply(Select(orig, extractor), List(Ident(nme.SELECTOR_DUMMY) setType fun.tpe.finalResultType)), EXPRmode, WildcardType), reportAmbiguousErrors = false) match { - case SilentResultValue(extractorCall) => extractorCall // if !extractorCall.containsError() - case _ => - // this fails to resolve overloading properly... - // Apply(typedOperator(Select(orig, extractor)), List(Ident(nme.SELECTOR_DUMMY))) // no need to set the type of the dummy arg, it will be replaced anyway - - // patmatDebug("funtpe after = "+ fun.tpe.finalResultType) - // patmatDebug("orig: "+(orig, orig.tpe)) - val tgt = typed(orig, EXPRmode | QUALmode | POLYmode, HasMember(extractor.name)) // can't specify fun.tpe.finalResultType as the type for the extractor's arg, - // as it may have been inferred incorrectly (see t602, where it's com.mosol.sl.Span[Any], instead of com.mosol.sl.Span[?K]) - // patmatDebug("tgt = "+ (tgt, tgt.tpe)) - val oper = typed(Select(tgt, extractor.name), EXPRmode | FUNmode | POLYmode | TAPPmode, WildcardType) - // patmatDebug("oper: "+ (oper, oper.tpe)) - Apply(oper, List(Ident(nme.SELECTOR_DUMMY))) // no need to set the type of the dummy arg, it will be replaced anyway - } - } finally context.undetparams = savedUndets - - Some(this(extractorCall, args)) // TODO: simplify spliceApply? - } - } + def apply(unfun: Tree, args: List[Tree]): ExtractorCall = new ExtractorCallRegular(unfun, args) + def fromCaseClass(fun: Tree, args: List[Tree]): Option[ExtractorCall] = Some(new ExtractorCallProd(fun, args)) } abstract class ExtractorCall(val args: List[Tree]) { @@ -900,7 +854,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL if (origTp == null || origTp == NoType) to // important: only type when actually substing and when original tree was typed // (don't need to use origTp as the expected type, though, and can't always do this anyway due to unknown type params stemming from polymorphic extractors) - else typer.typed(to, EXPRmode, WildcardType) + else typer.typed(to) override def transform(tree: Tree): Tree = { def subst(from: List[Symbol], to: List[Tree]): Tree = @@ -1197,7 +1151,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL type Result = Tree def and(a: Result, b: Result): Result = a AND b - def tru = TRUE_typed + def tru = mkTRUE def typeTest(testedBinder: Symbol, expectedTp: Type) = codegen._isInstanceOf(testedBinder, expectedTp) def nonNullTest(testedBinder: Symbol) = REF(testedBinder) OBJ_NE NULL def equalsTest(pat: Tree, testedBinder: Symbol) = codegen._equals(pat, testedBinder) @@ -1207,7 +1161,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL val expectedOuter = expectedTp.prefix match { case ThisType(clazz) => THIS(clazz) case pre if pre != NoType => REF(pre.prefix, pre.termSymbol) - case _ => TRUE_typed // fallback for SI-6183 + case _ => mkTRUE // fallback for SI-6183 } // ExplicitOuter replaces `Select(q, outerSym) OBJ_EQ expectedPrefix` by `Select(q, outerAccessor(outerSym.owner)) OBJ_EQ expectedPrefix` @@ -1360,10 +1314,10 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // one alternative may still generate multiple trees (e.g., an extractor call + equality test) // (for now,) alternatives may not bind variables (except wildcards), so we don't care about the final substitution built internally by makeTreeMakers val combinedAlts = altss map (altTreeMakers => - ((casegen: Casegen) => combineExtractors(altTreeMakers :+ TrivialTreeMaker(casegen.one(TRUE_typed)))(casegen)) + ((casegen: Casegen) => combineExtractors(altTreeMakers :+ TrivialTreeMaker(casegen.one(mkTRUE)))(casegen)) ) - val findAltMatcher = codegenAlt.matcher(EmptyTree, NoSymbol, BooleanClass.tpe)(combinedAlts, Some(x => FALSE_typed)) + val findAltMatcher = codegenAlt.matcher(EmptyTree, NoSymbol, BooleanClass.tpe)(combinedAlts, Some(x => mkFALSE)) codegenAlt.ifThenElseZero(findAltMatcher, substitution(next)) } } @@ -1506,10 +1460,8 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // local / context-free def _asInstanceOf(b: Symbol, tp: Type): Tree - def _asInstanceOf(t: Tree, tp: Type): Tree def _equals(checker: Tree, binder: Symbol): Tree def _isInstanceOf(b: Symbol, tp: Type): Tree - def and(a: Tree, b: Tree): Tree def drop(tgt: Tree)(n: Int): Tree def index(tgt: Tree)(i: Int): Tree def mkZero(tp: Type): Tree @@ -1523,7 +1475,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def flatMap(prev: Tree, b: Symbol, next: Tree): Tree def flatMapCond(cond: Tree, res: Tree, nextBinder: Symbol, next: Tree): Tree def flatMapGuard(cond: Tree, next: Tree): Tree - def ifThenElseZero(c: Tree, then: Tree): Tree = IF (c) THEN then ELSE zero + def ifThenElseZero(c: Tree, thenp: Tree): Tree = IF (c) THEN thenp ELSE zero protected def zero: Tree } @@ -1551,18 +1503,14 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL abstract class CommonCodegen extends AbsCodegen { import CODE._ def fun(arg: Symbol, body: Tree): Tree = Function(List(ValDef(arg)), body) - def genTypeApply(tfun: Tree, args: Type*): Tree = if(args contains NoType) tfun else TypeApply(tfun, args.toList map TypeTree) def tupleSel(binder: Symbol)(i: Int): Tree = (REF(binder) DOT nme.productAccessorName(i)) // make tree that accesses the i'th component of the tuple referenced by binder def index(tgt: Tree)(i: Int): Tree = tgt APPLY (LIT(i)) def drop(tgt: Tree)(n: Int): Tree = (tgt DOT vpmName.drop) (LIT(n)) def _equals(checker: Tree, binder: Symbol): Tree = checker MEMBER_== REF(binder) // NOTE: checker must be the target of the ==, that's the patmat semantics for ya - def and(a: Tree, b: Tree): Tree = a AND b // the force is needed mainly to deal with the GADT typing hack (we can't detect it otherwise as tp nor pt need contain an abstract type, we're just casting wildly) - def _asInstanceOf(t: Tree, tp: Type): Tree = if (t.tpe != NoType && t.isTyped && typesConform(t.tpe, tp)) t else gen.mkCastPreservingAnnotations(t, tp) def _asInstanceOf(b: Symbol, tp: Type): Tree = if (typesConform(b.info, tp)) REF(b) else gen.mkCastPreservingAnnotations(REF(b), tp) def _isInstanceOf(b: Symbol, tp: Type): Tree = gen.mkIsInstanceOf(REF(b), tp.withoutAnnotations, true, false) - // if (typesConform(b.info, tpX)) { patmatDebug("warning: emitted spurious isInstanceOf: "+(b, tp)); TRUE } // duplicated out of frustration with cast generation def mkZero(tp: Type): Tree = { @@ -1592,8 +1540,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL import CODE._ def _match(n: Name): SelectStart = matchStrategy DOT n - private lazy val oneSig: Type = - typer.typed(_match(vpmName.one), EXPRmode | POLYmode | TAPPmode | FUNmode, WildcardType).tpe // TODO: error message + private lazy val oneSig: Type = typer.typedOperator(_match(vpmName.one)).tpe // TODO: error message } trait PureCodegen extends CodegenCore with PureMatchMonadInterface { @@ -1611,7 +1558,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // __match.zero protected def zero: Tree = _match(vpmName.zero) // __match.guard(`c`, `then`) - def guard(c: Tree, then: Tree): Tree = _match(vpmName.guard) APPLY (c, then) + def guard(c: Tree, thenp: Tree): Tree = _match(vpmName.guard) APPLY (c, thenp) //// methods in the monad instance -- used directly in translation // `prev`.flatMap(`b` => `next`) @@ -1905,7 +1852,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def toString(x: AnyRef) = if (x eq null) "" else x.toString if (cols.isEmpty || cols.tails.isEmpty) cols map toString else { - val (colStrs, colLens) = cols map {c => val s = toString(c); (s, s.length)} unzip + val colLens = cols map (c => toString(c).length) val maxLen = max(colLens) val avgLen = colLens.sum/colLens.length val goalLen = maxLen min avgLen*2 @@ -2174,7 +2121,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // throws an AnalysisBudget.Exception when the prop results in a CNF that's too big // TODO: be smarter/more efficient about this (http://lara.epfl.ch/w/sav09:tseitin_s_encoding) def eqFreePropToSolvable(p: Prop): Formula = { - def negationNormalFormNot(p: Prop, budget: Int = AnalysisBudget.max): Prop = + def negationNormalFormNot(p: Prop, budget: Int): Prop = if (budget <= 0) throw AnalysisBudget.exceeded else p match { case And(a, b) => Or(negationNormalFormNot(a, budget - 1), negationNormalFormNot(b, budget - 1)) @@ -2388,9 +2335,9 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL private[this] val id: Int = Var.nextId // private[this] var canModify: Option[Array[StackTraceElement]] = None - private[this] def ensureCanModify = {} //if (canModify.nonEmpty) patmatDebug("BUG!"+ this +" modified after having been observed: "+ canModify.get.mkString("\n")) + private[this] def ensureCanModify() = {} //if (canModify.nonEmpty) patmatDebug("BUG!"+ this +" modified after having been observed: "+ canModify.get.mkString("\n")) - private[this] def observed = {} //canModify = Some(Thread.currentThread.getStackTrace) + private[this] def observed() = {} //canModify = Some(Thread.currentThread.getStackTrace) // don't access until all potential equalities have been registered using registerEquality private[this] val symForEqualsTo = new scala.collection.mutable.HashMap[Const, Sym] @@ -2543,7 +2490,13 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL private lazy val equalitySyms = {observed; symForEqualsTo.values.toList} // don't call until all equalities have been registered and registerNull has been called (if needed) - def describe = toString + ": " + staticTp + domain.map(_.mkString(" ::= ", " | ", "// "+ symForEqualsTo.keys)).getOrElse(symForEqualsTo.keys.mkString(" ::= ", " | ", " | ...")) + " // = " + path + def describe = { + def domain_s = domain match { + case Some(d) => d mkString (" ::= ", " | ", "// "+ symForEqualsTo.keys) + case _ => symForEqualsTo.keys mkString (" ::= ", " | ", " | ...") + } + s"$this: ${staticTp}${domain_s} // = $path" + } override def toString = "V"+ id } @@ -2629,7 +2582,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // corresponds to a type test that does not imply any value-equality (well, except for outer checks, which we don't model yet) sealed class TypeConst(val tp: Type) extends Const { assert(!(tp =:= NullTp)) - private[this] val id: Int = Const.nextTypeId + /*private[this] val id: Int = */ Const.nextTypeId val wideTp = widenToClass(tp) def isValue = false @@ -2667,7 +2620,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL } val toString = - if (p.hasSymbol && p.symbol.isStable) p.symbol.name.toString // tp.toString + if (hasStableSymbol(p)) p.symbol.name.toString // tp.toString else p.toString //+"#"+ id Const.unique(narrowTp, new ValueConst(narrowTp, checkableType(wideTp), toString)) // must make wide type checkable so that it is comparable to types from TypeConst @@ -2677,7 +2630,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL sealed class ValueConst(val tp: Type, val wideTp: Type, override val toString: String) extends Const { // patmatDebug("VC"+(tp, wideTp, toString)) assert(!(tp =:= NullTp)) // TODO: assert(!tp.isStable) - private[this] val id: Int = Const.nextValueId + /*private[this] val id: Int = */Const.nextValueId def isValue = true } @@ -2904,7 +2857,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // when does the match fail? val matchFails = Not(\/(symbolicCases)) - val vars = gatherVariables(matchFails) // debug output: patmatDebug("analysing:") @@ -3002,8 +2954,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL v +"(="+ v.path +": "+ v.staticTpCheckable +") "+ assignment }.mkString("\n") - def modelString(model: Model) = varAssignmentString(modelToVarAssignment(model)) - // return constructor call when the model is a true counter example // (the variables don't take into account type information derived from other variables, // so, naively, you might try to construct a counter example like _ :: Nil(_ :: _, _ :: _), @@ -3643,7 +3593,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL override def emitSwitch(scrut: Tree, scrutSym: Symbol, cases: List[List[TreeMaker]], pt: Type, matchFailGenOverride: Option[Tree => Tree], unchecked: Boolean): Option[Tree] = { import CODE._ val regularSwitchMaker = new RegularSwitchMaker(scrutSym, matchFailGenOverride, unchecked) // TODO: if patterns allow switch but the type of the scrutinee doesn't, cast (type-test) the scrutinee to the corresponding switchable type and switch on the result - if (regularSwitchMaker.switchableTpe(scrutSym.tpe.dealias)) { // TODO: switch to dealiasWiden in 2.11 + if (regularSwitchMaker.switchableTpe(dealiasWiden(scrutSym.tpe))) { val caseDefsWithDefault = regularSwitchMaker(cases map {c => (scrutSym, c)}, pt) if (caseDefsWithDefault isEmpty) None // not worth emitting a switch. else { @@ -3662,7 +3612,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // for the catch-cases in a try/catch private object typeSwitchMaker extends SwitchMaker { val unchecked = false - def switchableTpe(tp: Type) = true val alternativesSupported = false // TODO: needs either back-end support of flattening of alternatives during typers val canJump = false @@ -3708,11 +3657,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL trait OptimizedCodegen extends CodegenCore with TypedSubstitution with OptimizedMatchMonadInterface { override def codegen: AbsCodegen = optimizedCodegen - // trait AbsOptimizedCodegen extends AbsCodegen { - // def flatMapCondStored(cond: Tree, condSym: Symbol, res: Tree, nextBinder: Symbol, next: Tree): Tree - // } - // def optimizedCodegen: AbsOptimizedCodegen - // when we know we're targetting Option, do some inlining the optimizer won't do // for example, `o.flatMap(f)` becomes `if(o == None) None else f(o.get)`, similarly for orElse and guard // this is a special instance of the advanced inlining optimization that takes a method call on @@ -3815,7 +3759,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def flatMapCondStored(cond: Tree, condSym: Symbol, res: Tree, nextBinder: Symbol, next: Tree): Tree = ifThenElseZero(cond, BLOCK( - condSym === TRUE_typed, + condSym === mkTRUE, nextBinder === res, next )) |