diff options
5 files changed, 61 insertions, 18 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala index 8ae2e0a3b8..c6f80c9b20 100644 --- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala @@ -411,7 +411,17 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // TODO: extractor.paramType may contain unbound type params (run/t2800, run/t3530) // `patBinderOrCasted` is assigned the result of casting `patBinder` to `extractor.paramType` val (typeTestTreeMaker, patBinderOrCasted, binderKnownNonNull) = - if (needsTypeTest(patBinder.info.widen, extractor.paramType)) { + if (patBinder.info.widen <:< extractor.paramType) { + // no type test needed, but the tree maker relies on `patBinderOrCasted` having type `extractor.paramType` (and not just some type compatible with it) + // SI-6624 shows this is necessary because apparently patBinder may have an unfortunate type (.decls don't have the case field accessors) + // TODO: get to the bottom of this -- I assume it happens when type checking infers a weird type for an unapply call + // by going back to the parameterType for the extractor call we get a saner type, so let's just do that for now + /* TODO: uncomment when `settings.developer` and `devWarning` become available + if (settings.developer.value && !(patBinder.info =:= extractor.paramType)) + devWarning(s"resetting info of $patBinder: ${patBinder.info} to ${extractor.paramType}") + */ + (Nil, patBinder setInfo extractor.paramType, false) + } else { // chain a type-testing extractor before the actual extractor call // it tests the type, checks the outer pointer and casts to the expected type // TODO: the outer check is mandated by the spec for case classes, but we do it for user-defined unapplies as well [SPEC] @@ -422,16 +432,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // even though the eventual null check will be on patBinderOrCasted // it'll be equal to patBinder casted to extractor.paramType anyway (and the type test is on patBinder) (List(treeMaker), treeMaker.nextBinder, treeMaker.impliesBinderNonNull(patBinder)) - } else { - // no type test needed, but the tree maker relies on `patBinderOrCasted` having type `extractor.paramType` (and not just some type compatible with it) - // SI-6624 shows this is necessary because apparently patBinder may have an unfortunate type (.decls don't have the case field accessors) - // TODO: get to the bottom of this -- I assume it happens when type checking infers a weird type for an unapply call - // by going back to the parameterType for the extractor call we get a saner type, so let's just do that for now - /* TODO: uncomment when `settings.developer` and `devWarning` become available - if (settings.developer.value && !(patBinder.info =:= extractor.paramType)) - devWarning(s"resetting info of $patBinder: ${patBinder.info} to ${extractor.paramType}") - */ - (Nil, patBinder setInfo extractor.paramType, false) } withSubPats(typeTestTreeMaker :+ extractor.treeMaker(patBinderOrCasted, binderKnownNonNull, pos), extractor.subBindersAndPatterns: _*) @@ -1176,9 +1176,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL override def toString = "P"+(prevBinder.name, extraCond getOrElse "", localSubstitution) } - // typetag-based tests are inserted by the type checker - def needsTypeTest(tp: Type, pt: Type): Boolean = !(tp <:< pt) - object TypeTestTreeMaker { // factored out so that we can consistently generate other representations of the tree that implements the test // (e.g. propositions for exhaustivity and friends, boolean for isPureTypeTest) @@ -1192,12 +1189,14 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def equalsTest(pat: Tree, testedBinder: Symbol): Result def eqTest(pat: Tree, testedBinder: Symbol): Result def and(a: Result, b: Result): Result + def tru: Result } object treeCondStrategy extends TypeTestCondStrategy { import CODE._ type Result = Tree def and(a: Result, b: Result): Result = a AND b + def tru = TRUE_typed 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) @@ -1228,6 +1227,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def equalsTest(pat: Tree, testedBinder: Symbol): Result = false def eqTest(pat: Tree, testedBinder: Symbol): Result = false def and(a: Result, b: Result): Result = false // we don't and type tests, so the conjunction must include at least one false + def tru = true } def nonNullImpliedByTestChecker(binder: Symbol) = new TypeTestCondStrategy { @@ -1239,6 +1239,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def equalsTest(pat: Tree, testedBinder: Symbol): Result = false // could in principle analyse pat and see if it's statically known to be non-null def eqTest(pat: Tree, testedBinder: Symbol): Result = false // could in principle analyse pat and see if it's statically known to be non-null def and(a: Result, b: Result): Result = a || b + def tru = false } } @@ -1308,10 +1309,16 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // I think it's okay: // - the isInstanceOf test includes a test for the element type // - Scala's arrays are invariant (so we don't drop type tests unsoundly) - case _ if (expectedTp <:< AnyRefClass.tpe) && !needsTypeTest(testedBinder.info.widen, expectedTp) => - // do non-null check first to ensure we won't select outer on null - if (outerTestNeeded) and(nonNullTest(testedBinder), outerTest(testedBinder, expectedTp)) - else nonNullTest(testedBinder) + case _ if testedBinder.info.widen <:< expectedTp => + // if the expected type is a primitive value type, it cannot be null and it cannot have an outer pointer + // since the types conform, no further checking is required + if (expectedTp.typeSymbol.isPrimitiveValueClass) tru + // have to test outer and non-null only when it's a reference type + else if (expectedTp <:< AnyRefClass.tpe) { + // do non-null check first to ensure we won't select outer on null + if (outerTestNeeded) and(nonNullTest(testedBinder), outerTest(testedBinder, expectedTp)) + else nonNullTest(testedBinder) + } else default case _ => default } @@ -1823,6 +1830,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def nonNullTest(testedBinder: Symbol) = NonNullCond(binderToUniqueTree(testedBinder)) def equalsTest(pat: Tree, testedBinder: Symbol) = EqualityCond(binderToUniqueTree(testedBinder), unique(pat)) def eqTest(pat: Tree, testedBinder: Symbol) = EqualityCond(binderToUniqueTree(testedBinder), unique(pat)) // TODO: eq, not == + def tru = TrueCond } ttm.renderCondition(condStrategy) case EqualityTestTreeMaker(prevBinder, patTree, _) => EqualityCond(binderToUniqueTree(prevBinder), unique(patTree)) diff --git a/test/files/jvm/patmat_opt_primitive_typetest.check b/test/files/jvm/patmat_opt_primitive_typetest.check new file mode 100644 index 0000000000..43f53aba12 --- /dev/null +++ b/test/files/jvm/patmat_opt_primitive_typetest.check @@ -0,0 +1 @@ +bytecode identical diff --git a/test/files/jvm/patmat_opt_primitive_typetest.flags b/test/files/jvm/patmat_opt_primitive_typetest.flags new file mode 100644 index 0000000000..49d036a887 --- /dev/null +++ b/test/files/jvm/patmat_opt_primitive_typetest.flags @@ -0,0 +1 @@ +-optimize diff --git a/test/files/jvm/patmat_opt_primitive_typetest/Analyzed_1.scala b/test/files/jvm/patmat_opt_primitive_typetest/Analyzed_1.scala new file mode 100644 index 0000000000..c5b8811449 --- /dev/null +++ b/test/files/jvm/patmat_opt_primitive_typetest/Analyzed_1.scala @@ -0,0 +1,25 @@ +// this class's bytecode, compiled under -optimize is analyzed by the test +// method a's bytecode should be identical to method b's bytecode +class SameBytecode { + case class Foo(x: Int, y: String) + + def a = + Foo(1, "a") match { + case Foo(_: Int, y) => y + } + + // this method's body holds the tree that should be generated by the pattern matcher for method a (-Xprint:patmat) + // the test checks that bytecode for a and b is identical (modulo line numbers) + // we can't diff trees as they are quite different (patmat uses jumps to labels that cannot be expressed in source, for example) + // note that the actual tree is quite bad: we do an unnecessary null check, and local val (x3) + // some of these will be fixed soon (the initial null check is for the scrutinee, which is harder to fix in patmat) + def b: String = { + val x1 = Foo(1, "a") + if (x1.ne(null)) { + val x3 = x1.x + return x1.y + } + + throw new MatchError(x1) + } +}
\ No newline at end of file diff --git a/test/files/jvm/patmat_opt_primitive_typetest/test.scala b/test/files/jvm/patmat_opt_primitive_typetest/test.scala new file mode 100644 index 0000000000..2927e763d5 --- /dev/null +++ b/test/files/jvm/patmat_opt_primitive_typetest/test.scala @@ -0,0 +1,8 @@ +import scala.tools.partest.BytecodeTest + +object Test extends BytecodeTest { + def show: Unit = { + val classNode = loadClassNode("SameBytecode") + sameBytecode(getMethod(classNode, "a"), getMethod(classNode, "b")) + } +} |