我已经在这个问题上陷入了一周,但似乎没有任何进展。我正在尝试将一些方法和字段从一个类复制到另一个类。
我有两个阶段参与其中。第一阶段扫描代码,找到需要复制的方法def,并保存对应的Tree
第二阶段将这棵树插入到需要的地方。为了简化这个问题,让我们忘记复制并说我正在尝试插入一个简单的方法def hello(): String = "hello"
到某个阶级的身体
该插件在之后运行typer
(因为我需要包信息),并且我在正确注入类型信息时遇到问题。这会导致后面的断言异常type checking
阶段(底部的完整堆栈跟踪)
我在metaprogramming
不和谐并被指出以下资源。
Scala 编译器插件重写方法调用 https://stackoverflow.com/questions/26219175/scala-compiler-plugin-to-rewrite-method-calls
https://contributors.scala-lang.org/t/scala-compiler-plugin-naming-issues-after-typer/2835 https://contributors.scala-lang.org/t/scala-compiler-plugin-naming-issues-after-typer/2835
但不幸的是,两者都没有取得成功的结果。我假设我必须特别小心,因为返回类型是原始类型(?),因为该类型通过Predef
第一次尝试:
结果最后出现错误
tree match {
case pl @ ClassDef(mods, name, tparams, e @ Template(parent, self, body)) =>
parent.lift(1) match {
case Some(a @ TypeTree()) =>
a.original match {
case AppliedTypeTree(Select(This(TypeName(s)), tpt), args) =>
if (tpt.toString == "Policy") {
val insert = q""" def q(): String = {"hello"}""".asInstanceOf[DefDef]
val DefDef(dmodifiers, dname, dtparams, dvparams, dtpt, drhs) = insert
val source = treeCopy.DefDef(insert, dmodifiers, dname, dtparams, dvparams, dtpt, drhs)
val finalCopy = pl.copy(
mods,
name,
tparams,
Template(
parent,
self,
body.:+(
source
)
)
)
localTyper.typed(finalCopy)
} else {
super.transform(tree)
}
case _ => super.transform(tree)
}
case _ => super.transform(tree)
}
case _ => super.transform(tree)
}
而不是建造source
,我也尝试过手动构建各种东西。
DefDef(
Modifiers(),
TermName("q"),
List(),
List(List()),
TypeTree().setOriginal(Select(Select(Ident(scala), scala.Predef), TypeName("String"))), //attempt1
Ident(TypeName("String")), //attemp2
TypeTree().setOriginal(Ident(TypeName("String"))), //attempt3
gen.mkAttributedRef(typeOf[String].typeSymbol), //attempt 4
Literal(Constant("hello")))
所有这些都会导致相同的错误。请注意,在错误中,正在打印的类已插入方法,但类型检查器由于某种原因无法理解它
根据贡献者论坛上的建议,我尝试设置所有权
val source = ... same as above
pl.symbol.owner.info.decls.unlink(pl.symbol)
localTyper.namer.enterDefDef(source)
source.symbol.owner.info.decls.enter(pl.symbol)
val finalCopy = pl.copy(....) //same as above
localTyper.namer.enterClassDef(finalCopy)
finalCopy.symbol.owner.info.decls.enter(finalCopy.symbol)
localTyper.typed(finalCopy)
但这完全搞砸了一切,编译器弄乱了符号,并告诉我完全实现的类没有实现抽象成员,因此需要声明abstract
我一直在绕圈子,所以如果有人知道在之后将方法附加到类主体的最佳方法是什么typer
或者有一些相关的例子,我当然会很感激
Exception in thread "main" java.lang.AssertionError: assertion failed:
[error] class UserPolicy extends AnyRef with prv.Main.Policy[prv.Main.User] {
[error] <paramaccessor> private[this] val u: prv.Main.User = _;
[error] def <init>(u: prv.Main.User): prv.Main.UserPolicy = {
[error] UserPolicy.super.<init>();
[error] ()
[error] };
[error] private[this] val data: prv.Main.User = UserPolicy.this.u;
[error] <stable> <accessor> def data: prv.Main.User = UserPolicy.this.data;
[error] protected def checkDeclassify(): prv.Main.User = {
[error] def checkExpanded(): prv.Main.User = UserPolicy.this.data;
[error] checkExpanded()
[error] };
[error] def unsafeUnwrap(reason: String): prv.Main.User = UserPolicy.this.data;
[error] def q2(): String = "hello";
[error] def q(): String = "hello"
[error] }
[error] while compiling: <test>
[error] during phase: method-wiring-phase
[error] library version: version 2.13.1
[error] compiler version: version 2.13.1
[error] reconstructed args: -usejavacp
[error] last tree to typer: type UserPolicy
[error] tree position: <unknown>
[error] symbol: <none>
[error] symbol definition: <none> (a NoSymbol)
[error] symbol package: <none>
[error] symbol owners:
[error] call site: <none> in <none>
[error] == Source file context for tree position ==
[error] at scala.reflect.internal.SymbolTable.throwAssertionError(SymbolTable.scala:170)
[error] at scala.tools.nsc.typechecker.Typers$Typer.typedClassDef(Typers.scala:1876)
[error] at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5794)
[error] at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5886)
[error] at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5948)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:254)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:195)
[error] at scala.reflect.api.Trees$Transformer.$anonfun$transformStats$1(Trees.scala:2614)
[error] at scala.reflect.api.Trees$Transformer.transformStats(Trees.scala:2612)
[error] at scala.reflect.internal.Trees$Template.transform(Trees.scala:517)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.$anonfun$transform$1(TypingTransformers.scala:47)
[error] at scala.reflect.api.Trees$Transformer.atOwner(Trees.scala:2625)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:37)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.transform(TypingTransformers.scala:32)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:333)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:195)
[error] at scala.reflect.api.Trees$Transformer.transformTemplate(Trees.scala:2587)
[error] at scala.reflect.internal.Trees$ModuleDef.$anonfun$transform$3(Trees.scala:370)
[error] at scala.reflect.api.Trees$Transformer.atOwner(Trees.scala:2625)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:37)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:32)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:24)
[error] at scala.reflect.internal.Trees$ModuleDef.transform(Trees.scala:369)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.transform(TypingTransformers.scala:51)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:333)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:195)
[error] at scala.reflect.api.Trees$Transformer.$anonfun$transformStats$1(Trees.scala:2614)
[error] at scala.reflect.api.Trees$Transformer.transformStats(Trees.scala:2612)
[error] at scala.reflect.internal.Trees$PackageDef.$anonfun$transform$1(Trees.scala:316)
[error] at scala.reflect.api.Trees$Transformer.atOwner(Trees.scala:2625)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:37)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:32)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:24)
[error] at scala.reflect.internal.Trees$PackageDef.transform(Trees.scala:316)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.$anonfun$transform$2(TypingTransformers.scala:49)
[error] at scala.reflect.api.Trees$Transformer.atOwner(Trees.scala:2625)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.atOwner(TypingTransformers.scala:37)
[error] at scala.tools.nsc.transform.TypingTransformers$TypingTransformer.transform(TypingTransformers.scala:32)
[error] at privacy.MethodWiring$MethodWiringPhase.transform(MethodWire.scala:333)
[error] at privacy.MethodWiring$$anon$3.apply(MethodWire.scala:192)
[error] at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:452)
[error] at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:397)
[error] at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1506)
[error] at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1490)
[error] at scala.tools.nsc.Global$Run.compileSources(Global.scala:1482)
[error] at privacy.AnnotationFinderTest$.delayedEndpoint$privacy$AnnotationFinderTest$1(Test.scala:114)
[error] at privacy.AnnotationFinderTest$delayedInit$body.apply(Test.scala:13)
[error] at scala.Function0.apply$mcV$sp(Function0.scala:39)
[error] at scala.Function0.apply$mcV$sp$(Function0.scala:39)
[error] at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:17)
[error] at scala.App.$anonfun$main$1(App.scala:73)
[error] at scala.App.$anonfun$main$1$adapted(App.scala:73)
[error] at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:553)
[error] at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:551)
[error] at scala.collection.AbstractIterable.foreach(Iterable.scala:921)
[error] at scala.App.main(App.scala:73)
[error] at scala.App.main$(App.scala:71)
[error] at privacy.AnnotationFinderTest$.main(Test.scala:13)
[error] at privacy.AnnotationFinderTest.main(Test.scala)