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Do you see why this slains the compiler?
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| import scala.reflect.macros.Context | |
| import scala.reflect.api.Universe | |
| object Foo { | |
| def doit[T](t: T) = ??? | |
| def bar[T](body: T): Option[T] = macro barImpl[T] | |
| def barImpl[T: c.WeakTypeTag](c: Context)(body: c.Expr[T]): c.Expr[Option[T]] = { | |
| import c.universe._, c.internal._, decorators._, Flag._ | |
| def doitMethod(u: Universe)(macroSymbol: u.Symbol): u.Symbol = { | |
| import u._ | |
| macroSymbol.owner.typeSignature.member(newTermName("doit")) | |
| } | |
| lazy val doitSymbol = doitMethod(c.universe)(c.macroApplication.symbol).ensuring(_ != NoSymbol) | |
| val res = typingTransform(body.tree)((tree, api) => { | |
| def defineVal(prefix: String, lhs: Tree, pos: Position): ValDef = { | |
| val sym = api.currentOwner.newTermSymbol(c.freshName(prefix), pos, SYNTHETIC).setInfo(lhs.tpe) | |
| lhs.changeOwner(api.currentOwner, sym) | |
| valDef(sym, lhs.changeOwner(api.currentOwner, sym)).setType(NoType).setPos(pos) | |
| } | |
| def defineParam(prefix: String, pos: Position, tpe: Type): ValDef = { | |
| val sym = api.currentOwner.newTermSymbol(c.freshName(prefix), pos, PARAM).setInfo(tpe) | |
| valDef(sym).setType(tpe).setPos(pos) | |
| } | |
| tree match { | |
| case q"$fun($t)" if(fun.symbol == doitSymbol) => | |
| /** | |
| Foo.bar[Int](5) should generate this code: | |
| { | |
| <synthetic> val toto$macro$148: Some[Int] = scala.Some.apply[Int](5); | |
| <synthetic> val toto$macro$151: Option[Int] = toto$macro$148.map[Int](((t$macro$149: Int) => { | |
| <synthetic> val toto$macro$150: Int = { | |
| scala.this.Predef.println("result:".+(t$macro$149)); | |
| t$macro$149 | |
| }; | |
| toto$macro$150 | |
| })); | |
| toto$macro$151 | |
| } | |
| */ | |
| // GENERATES: | |
| // <synthetic> val toto$macro$148: Some[Int] = scala.Some.apply[Int](5); | |
| val code = api.typecheck(q"Some($t)") | |
| val valDef = defineVal("toto", code, tree.pos) | |
| val valDefRef = gen.mkAttributedRef(valDef.symbol).setType(code.tpe).setPos(tree.pos) | |
| val tpe = implicitly[WeakTypeTag[T]].tpe | |
| val param = defineParam("t", tree.pos, tpe) | |
| val paramRef = gen.mkAttributedRef(param.symbol).setType(tpe).setPos(tree.pos) | |
| // GENERATES: | |
| // scala.this.Predef.println("result:".+(t$macro$149)); | |
| // toto$macro$149 | |
| // | |
| val innerCode = api.typecheck(q""" | |
| println("result:"+$paramRef) | |
| $paramRef | |
| """) | |
| // GENERATES: | |
| // <synthetic> val toto$macro$150: Int = { | |
| // scala.this.Predef.println("result:".+(t$macro$149)); | |
| // toto$macro$149 | |
| // }; | |
| // toto$macro$150 | |
| val valInner = defineVal("toto", innerCode, tree.pos) | |
| val valInnerRef = gen.mkAttributedRef(valInner.symbol).setType(innerCode.tpe).setPos(tree.pos) | |
| val inner = Block(List(valInner), valInnerRef) | |
| // GENERATES: | |
| // <synthetic> val toto$macro$151: Option[Int] = toto$macro$148.map[Int](((t$macro$149: Int) => { | |
| // <synthetic> val toto$macro$150: Int = { | |
| // scala.this.Predef.println("result:".+(t$macro$149)); | |
| // t$macro$149 | |
| // }; | |
| // toto$macro$150 | |
| // })); | |
| val code2 = api.typecheck(q""" | |
| $valDefRef.map[$tpe]( ($param) => $inner ) | |
| """) | |
| val valDef2 = defineVal("toto", code2, tree.pos) | |
| val valDefRef2 = gen.mkAttributedRef(valDef2.symbol).setType(code.tpe).setPos(tree.pos) | |
| // GENERATES: | |
| // { | |
| // <synthetic> val toto$macro$148: Some[Int] = scala.Some.apply[Int](5); | |
| // <synthetic> val toto$macro$151: Option[Int] = toto$macro$148.map[Int](((t$macro$149: Int) => { | |
| // <synthetic> val toto$macro$150: Int = { | |
| // scala.this.Predef.println("result:".+(t$macro$149)); | |
| // t$macro$149 | |
| // }; | |
| // toto$macro$150 | |
| // })); | |
| // toto$macro$151 | |
| // } | |
| Block(List(valDef, valDef2), valDefRef2) | |
| case e => e | |
| } | |
| }) | |
| println("CODE:"+res) | |
| println("AST:"+showRaw(res, printTypes = true, /*printIds = true,*/ printKinds = true)) | |
| c.Expr[Option[T]](res) | |
| } | |
| } | |
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| scala> import Foo._ | |
| import Foo._ | |
| scala> Foo.bar[Int]{ doit(5) } | |
| CODE:{ | |
| <synthetic> val toto$macro$161: Some[Int] = scala.Some.apply[Int](5); | |
| <synthetic> val toto$macro$164: Option[Int] = toto$macro$161.map[Int](((t$macro$162: Int) => { | |
| <synthetic> val toto$macro$163: Int = { | |
| scala.this.Predef.println("result:".+(t$macro$162)); | |
| t$macro$162 | |
| }; | |
| toto$macro$163 | |
| })); | |
| toto$macro$164 | |
| } | |
| AST:Block(List(ValDef[23](Modifiers(SYNTHETIC), TermName("toto$macro$161")#VAL, TypeTree[41](), Apply[41](TypeApply[92](Select[29](Select[93](Ident[94](scala#PK), scala.Some#MOD), TermName("apply")#METH), List(TypeTree[10]())), List(Literal[95](Constant(5))))), ValDef[23](Modifiers(SYNTHETIC), TermName("toto$macro$164")#VAL, TypeTree[61](), Apply[61](TypeApply[96](Select[97](Ident[41](TermName("toto$macro$161")#VAL), TermName("map")#METH), List(TypeTree[10]())), List(Function[64](List(ValDef[23](Modifiers(PARAM), TermName("t$macro$162")#VAL, TypeTree[10](), EmptyTree)), Block[10](List(ValDef[23](Modifiers(SYNTHETIC), TermName("toto$macro$163")#VAL, TypeTree[10](), Block[10](List(Apply[77](Select[78](Select[98](This[80](TypeName("scala")), scala.Predef#MOD), TermName("println")#METH), List(Apply[81](Select[82](Literal[99](Constant("result:")), TermName("$plus")#METH), List(Ident[10](TermName("t$macro$162")#VAL)))))), Ident[10](TermName("t$macro$162")#VAL)))), Ident[10](TermName("toto$macro$163")#VAL))))))), Ident[41](TermName("toto$macro$164")#VAL)) | |
| [10] TypeRef(ThisType(scala#PKC), scala.Int#CLS, List()) | |
| [23] NoType | |
| [29] PolyType(List(TypeName("A")#TPE), MethodType(List(TermName("x")#VAL), TypeRef(ThisType(scala#PKC), scala.Some#CLS, List(TypeRef(NoPrefix, TypeName("A")#TPE, List()))))) | |
| [41] TypeRef(ThisType(scala#PKC), scala.Some#CLS, List(TypeRef(ThisType(scala#PKC), scala.Int#CLS, List()))) | |
| [61] TypeRef(ThisType(scala#PKC), scala.Option#CLS, List(TypeRef(ThisType(scala#PKC), scala.Int#CLS, List()))) | |
| [64] TypeRef(ThisType(scala#PKC), scala.Function1#TRT, List(TypeRef(ThisType(scala#PKC), scala.Int#CLS, List()), TypeRef(ThisType(scala#PKC), scala.Int#CLS, List()))) | |
| [77] TypeRef(ThisType(scala#PKC), scala.Unit#CLS, List()) | |
| [78] MethodType(List(TermName("x")#VAL), TypeRef(ThisType(scala#PKC), scala.Unit#CLS, List())) | |
| [80] ThisType(scala#PKC) | |
| [81] TypeRef(ThisType(java.lang#PKC), java.lang.String#CLS, List()) | |
| [82] MethodType(List(TermName("x$1")#VAL), TypeRef(ThisType(java.lang#PKC), java.lang.String#CLS, List())) | |
| [92] MethodType(List(TermName("x")#VAL), TypeRef(ThisType(scala#PKC), scala.Some#CLS, List(TypeRef(ThisType(scala#PKC), scala.Int#CLS, List())))) | |
| [93] SingleType(SingleType(ThisType(<root>#PKC), scala#PK), scala.Some#MOD) | |
| [94] SingleType(ThisType(<root>#PKC), scala#PK) | |
| [95] ConstantType(Constant(5)) | |
| [96] MethodType(List(TermName("f")#VAL), TypeRef(ThisType(scala#PKC), scala.Option#CLS, List(TypeRef(ThisType(scala#PKC), scala.Int#CLS, List())))) | |
| [97] PolyType(List(TypeName("B")#TPE), MethodType(List(TermName("f")#VAL), TypeRef(ThisType(scala#PKC), scala.Option#CLS, List(TypeRef(NoPrefix, TypeName("B")#TPE, List()))))) | |
| [98] SingleType(ThisType(scala#PKC), scala.Predef#MOD) | |
| [99] ConstantType(Constant(result:)) | |
| java.lang.IllegalArgumentException: Could not find proxy for t$macro$162: Int in List(value t$macro$162, method apply$mcII$sp, <$anon: Function1>, value toto$macro$164, value res7, object $iw, object $iw, object $iw, object $iw, object $read, package $line179, package <root>) (currentOwner= value toto$macro$163 ) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:317) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$searchIn$1(LambdaLift.scala:322) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.proxy(LambdaLift.scala:331) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.scala$tools$nsc$transform$LambdaLift$LambdaLifter$$proxyRef(LambdaLift.scala:364) | |
| at scala.tools.nsc.transform.LambdaLift$LambdaLifter.postTransform(LambdaLift.scala:503) | |
| ... |
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