From 6c7f2b6460de1aa6d15a6005921ca50e98a54027 Mon Sep 17 00:00:00 2001 From: Lukas Rytz Date: Thu, 5 Jul 2012 11:12:46 +0200 Subject: SI-5907, SI-5009 case-class copy defaults only for first param list `copy` no longer returns anonymous functions if there are multiple parameter lists, reverts most of 40e7cab7a2. Cleaned up the special type completer for copy methods. --- .../scala/tools/nsc/typechecker/Namers.scala | 43 ++++++------- .../scala/tools/nsc/typechecker/Unapplies.scala | 73 ++++++++++++++-------- 2 files changed, 66 insertions(+), 50 deletions(-) (limited to 'src') diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala index decd18b599..6428173577 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala @@ -502,32 +502,29 @@ trait Namers extends MethodSynthesis { noDuplicates(selectors map (_.rename), AppearsTwice) } - def enterCopyMethodOrGetter(tree: Tree, tparams: List[TypeDef]): Symbol = { - val sym = tree.symbol - val lazyType = completerOf(tree, tparams) - def completeCopyFirst = sym.isSynthetic && (!sym.hasDefault || sym.owner.info.member(nme.copy).isSynthetic) - def completeCopyMethod(clazz: Symbol) { - // the 'copy' method of case classes needs a special type completer to make - // bug0054.scala (and others) work. the copy method has to take exactly the same - // parameter types as the primary constructor. + def enterCopyMethod(copyDefDef: Tree, tparams: List[TypeDef]): Symbol = { + val sym = copyDefDef.symbol + val lazyType = completerOf(copyDefDef, tparams) + + /** Assign the types of the class parameters to the parameters of the + * copy method. See comment in `Unapplies.caseClassCopyMeth` */ + def assignParamTypes() { + val clazz = sym.owner val constructorType = clazz.primaryConstructor.tpe - val subst = new SubstSymMap(clazz.typeParams, tparams map (_.symbol)) - val vparamss = tree match { case x: DefDef => x.vparamss ; case _ => Nil } - val cparamss = constructorType.paramss - - map2(vparamss, cparamss)((vparams, cparams) => - map2(vparams, cparams)((param, cparam) => - // need to clone the type cparam.tpe??? - // problem is: we don't have the new owner yet (the new param symbol) - param.tpt setType subst(cparam.tpe) + val subst = new SubstSymMap(clazz.typeParams, tparams map (_.symbol)) + val classParamss = constructorType.paramss + val DefDef(_, _, _, copyParamss, _, _) = copyDefDef + + map2(copyParamss, classParamss)((copyParams, classParams) => + map2(copyParams, classParams)((copyP, classP) => + copyP.tpt setType subst(classP.tpe) ) ) } - sym setInfo { - mkTypeCompleter(tree) { copySym => - if (completeCopyFirst) - completeCopyMethod(copySym.owner) + sym setInfo { + mkTypeCompleter(copyDefDef) { sym => + assignParamTypes() lazyType complete sym } } @@ -604,8 +601,8 @@ trait Namers extends MethodSynthesis { val bridgeFlag = if (mods hasAnnotationNamed tpnme.bridgeAnnot) BRIDGE else 0 val sym = assignAndEnterSymbol(tree) setFlag bridgeFlag - if (name == nme.copy || tree.symbol.name.startsWith(nme.copy + nme.DEFAULT_GETTER_STRING)) - enterCopyMethodOrGetter(tree, tparams) + if (name == nme.copy && sym.isSynthetic) + enterCopyMethod(tree, tparams) else sym setInfo completerOf(tree, tparams) } diff --git a/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala b/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala index 4c20d14406..1b89f3db44 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala @@ -197,42 +197,61 @@ trait Unapplies extends ast.TreeDSL ) } + /** + * Generates copy methods for case classes. Copy only has defaults on the first + * parameter list, as of SI-5009. + * + * The parameter types of the copy method need to be exactly the same as the parameter + * types of the primary constructor. Just copying the TypeTree is not enough: a type `C` + * might refer to something else *inside* the class (i.e. as parameter type of `copy`) + * than *outside* the class (i.e. in the class parameter list). + * + * One such example is t0054.scala: + * class A { + * case class B(x: C) extends A { def copy(x: C = x) = ... } + * class C {} ^ ^ + * } (1) (2) + * + * The reference (1) to C is `A.this.C`. The reference (2) is `B.this.C` - not the same. + * + * This is fixed with a hack currently. `Unapplies.caseClassCopyMeth`, which creates the + * copy method, uses empty `TypeTree()` nodes for parameter types. + * + * In `Namers.enterDefDef`, the copy method gets a special type completer (`enterCopyMethod`). + * Before computing the body type of `copy`, the class parameter types are assigned the copy + * method parameters. + * + * This attachment class stores the copy method parameter ValDefs as an attachment in the + * ClassDef of the case class. + */ def caseClassCopyMeth(cdef: ClassDef): Option[DefDef] = { def isDisallowed(vd: ValDef) = isRepeatedParamType(vd.tpt) || isByNameParamType(vd.tpt) - val cparamss = constrParamss(cdef) - val flat = cparamss.flatten + val classParamss = constrParamss(cdef) - if (cdef.symbol.hasAbstractFlag || (flat exists isDisallowed)) None + if (cdef.symbol.hasAbstractFlag || mexists(classParamss)(isDisallowed)) None else { + def makeCopyParam(vd: ValDef, putDefault: Boolean) = { + val rhs = if (putDefault) toIdent(vd) else EmptyTree + val flags = PARAM | (vd.mods.flags & IMPLICIT) | (if (putDefault) DEFAULTPARAM else 0) + // empty tpt: see comment above + val tpt = atPos(vd.pos.focus)(TypeTree() setOriginal vd.tpt) + treeCopy.ValDef(vd, Modifiers(flags), vd.name, tpt, rhs) + } + val tparams = cdef.tparams map copyUntypedInvariant - // the parameter types have to be exactly the same as the constructor's parameter types; so it's - // not good enough to just duplicated the (untyped) tpt tree; the parameter types are removed here - // and re-added in ``finishWith'' in the namer. - def paramWithDefault(vd: ValDef) = - treeCopy.ValDef(vd, vd.mods | DEFAULTPARAM, vd.name, atPos(vd.pos.focus)(TypeTree() setOriginal vd.tpt), toIdent(vd)) - - val (copyParamss, funParamss) = cparamss match { - case Nil => (Nil, Nil) + val paramss = classParamss match { + case Nil => Nil case ps :: pss => - (List(ps.map(paramWithDefault)), mmap(pss)(p => copyUntyped[ValDef](p).copy(rhs = EmptyTree))) + ps.map(makeCopyParam(_, putDefault = true)) :: mmap(pss)(makeCopyParam(_, putDefault = false)) } val classTpe = classType(cdef, tparams) - val bodyTpe = funParamss.foldRight(classTpe)((params, restp) => gen.scalaFunctionConstr(params.map(_.tpt), restp)) - - val argss = copyParamss match { - case Nil => Nil - case ps :: _ => mmap(ps :: funParamss)(toIdent) - } - def mkFunction(vparams: List[ValDef], body: Tree) = Function(vparams, body) - val body = funParamss.foldRight(New(classTpe, argss): Tree)(mkFunction) - // [Eugene++] no longer compiles after I moved the `Function` case class into scala.reflect.internal - // val body = funParamss.foldRight(New(classTpe, argss): Tree)(Function) - - Some(atPos(cdef.pos.focus)( - DefDef(Modifiers(SYNTHETIC), nme.copy, tparams, copyParamss, bodyTpe, - body) - )) + val argss = mmap(paramss)(toIdent) + val body: Tree = New(classTpe, argss) + val copyDefDef = atPos(cdef.pos.focus)( + DefDef(Modifiers(SYNTHETIC), nme.copy, tparams, paramss, TypeTree(), body) + ) + Some(copyDefDef) } } } -- cgit v1.2.3