Support use-site meta-annotations

compiler/src/dotty/tools/dotc/core/Annotations.scala

@@ -2,12 +2,13 @@ package dotty.tools
 package dotc
 package core
 
-import Symbols._, Types._, Contexts._, Constants._
-import dotty.tools.dotc.ast.tpd, tpd.*
+import Symbols._, Types._, Contexts._, Constants._, Phases.*
+import ast.tpd, tpd.*
 import util.Spans.Span
 import printing.{Showable, Printer}
 import printing.Texts.Text
-import annotation.internal.sharable
+
+import scala.annotation.internal.sharable
 
 object Annotations {
 
@@ -87,6 +88,20 @@ object Annotations {
     def sameAnnotation(that: Annotation)(using Context): Boolean =
       symbol == that.symbol && tree.sameTree(that.tree)
 
+    def hasOneOfMetaAnnotation(metaSyms: Symbol*)(using Context): Boolean = atPhaseNoLater(erasurePhase) {
+      def recTp(tp: Type): Boolean = tp.dealiasKeepAnnots match
+        case AnnotatedType(parent, metaAnnot) => metaSyms.exists(metaAnnot.matches) || recTp(parent)
+        case _ => false
+      def rec(tree: Tree): Boolean = methPart(tree) match
+        case New(tpt) => rec(tpt)
+        case Select(qual, _) => rec(qual)
+        case Annotated(arg, metaAnnot) => metaSyms.exists(metaAnnot.tpe.classSymbol.derivesFrom) || rec(arg)
+        case t @ Ident(_) => recTp(t.tpe)
+        case Typed(expr, _) => rec(expr)
+        case _ => false
+      metaSyms.exists(symbol.hasAnnotation) || rec(tree)
+    }
+
     /** Operations for hash-consing, can be overridden */
     def hash: Int = System.identityHashCode(this)
     def eql(that: Annotation) = this eq that

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -1021,6 +1021,8 @@ class Definitions {
   @tu lazy val UncheckedVarianceAnnot: ClassSymbol = requiredClass("scala.annotation.unchecked.uncheckedVariance")
   @tu lazy val VolatileAnnot: ClassSymbol = requiredClass("scala.volatile")
   @tu lazy val WithPureFunsAnnot: ClassSymbol = requiredClass("scala.annotation.internal.WithPureFuns")
+  @tu lazy val BeanGetterMetaAnnot: ClassSymbol = requiredClass("scala.annotation.meta.beanGetter")
+  @tu lazy val BeanSetterMetaAnnot: ClassSymbol = requiredClass("scala.annotation.meta.beanSetter")
   @tu lazy val FieldMetaAnnot: ClassSymbol = requiredClass("scala.annotation.meta.field")
   @tu lazy val GetterMetaAnnot: ClassSymbol = requiredClass("scala.annotation.meta.getter")
   @tu lazy val ParamMetaAnnot: ClassSymbol = requiredClass("scala.annotation.meta.param")
@@ -1037,8 +1039,10 @@ class Definitions {
   @tu lazy val JavaRepeatableAnnot: ClassSymbol = requiredClass("java.lang.annotation.Repeatable")
 
   // A list of meta-annotations that are relevant for fields and accessors
-  @tu lazy val FieldAccessorMetaAnnots: Set[Symbol] =
+  @tu lazy val NonBeanMetaAnnots: Set[Symbol] =
     Set(FieldMetaAnnot, GetterMetaAnnot, ParamMetaAnnot, SetterMetaAnnot)
+  @tu lazy val MetaAnnots: Set[Symbol] =
+    NonBeanMetaAnnots + BeanGetterMetaAnnot + BeanSetterMetaAnnot
 
   // A list of annotations that are commonly used to indicate that a field/method argument or return
   // type is not null. These annotations are used by the nullification logic in JavaNullInterop to

compiler/src/dotty/tools/dotc/transform/BeanProperties.scala

@@ -34,9 +34,12 @@ class BeanProperties(thisPhase: DenotTransformer):
         info = MethodType(Nil, valDef.denot.info),
         coord = annot.tree.span
       ).enteredAfter(thisPhase).asTerm
-      meth.addAnnotations(valDef.symbol.annotations)
+      val annots = valDef.symbol.annotations.filterConserve { a =>
+        a.hasOneOfMetaAnnotation(defn.BeanGetterMetaAnnot)
+      }
+      meth.addAnnotations(annots)
       val body: Tree = ref(valDef.symbol)
-      DefDef(meth, body)
+      DefDef(meth, body).withSpan(meth.span)
 
     def maybeGenerateSetter(valDef: ValDef, annot: Annotation)(using Context): Option[Tree] =
       Option.when(valDef.denot.asSymDenotation.flags.is(Mutable)) {
@@ -48,9 +51,12 @@ class BeanProperties(thisPhase: DenotTransformer):
           info = MethodType(valDef.name :: Nil, valDef.denot.info :: Nil, defn.UnitType),
           coord = annot.tree.span
         ).enteredAfter(thisPhase).asTerm
-        meth.addAnnotations(valDef.symbol.annotations)
+        val annots = valDef.symbol.annotations.filterConserve { a =>
+          a.hasOneOfMetaAnnotation(defn.BeanSetterMetaAnnot)
+        }
+        meth.addAnnotations(annots)
         def body(params: List[List[Tree]]): Tree = Assign(ref(valDef.symbol), params.head.head)
-        DefDef(meth, body)
+        DefDef(meth, body).withSpan(meth.span)
       }
 
     def prefixedName(prefix: String, valName: Name) =

compiler/src/dotty/tools/dotc/transform/Memoize.scala

@@ -4,7 +4,7 @@ package transform
 import core._
 import DenotTransformers._
 import Contexts._
-import Phases.phaseOf
+import Phases.*
 import SymDenotations.SymDenotation
 import Denotations._
 import Symbols._
@@ -108,29 +108,24 @@ class Memoize extends MiniPhase with IdentityDenotTransformer { thisPhase =>
         if (sym.isGetter) sym.info.resultType
         else /*sym.isSetter*/ sym.info.firstParamTypes.head
 
-      newSymbol(
+      val fieldSym = newSymbol(
         owner = ctx.owner,
         name  = sym.name.asTermName.fieldName,
         flags = Private | (if (sym.is(StableRealizable)) EmptyFlags else Mutable),
         info  = fieldType,
         coord = tree.span
-      ).withAnnotationsCarrying(sym, defn.FieldMetaAnnot)
-       .enteredAfter(thisPhase)
-    }
-
-    def addAnnotations(denot: Denotation): Unit =
-      denot match {
-        case fieldDenot: SymDenotation if sym.annotations.nonEmpty =>
-          val cpy = fieldDenot.copySymDenotation()
-          cpy.annotations = sym.annotations
-          cpy.installAfter(thisPhase)
-        case _ => ()
+      )
+      fieldSym.annotations = sym.annotations.filterConserve { annot =>
+        annot.hasOneOfMetaAnnotation(defn.FieldMetaAnnot)
+        || !annot.hasOneOfMetaAnnotation(defn.MetaAnnots.toList*)
       }
+      fieldSym.enteredAfter(thisPhase)
+    }
 
     def removeUnwantedAnnotations(denot: SymDenotation, metaAnnotSym: ClassSymbol): Unit =
       if (sym.annotations.nonEmpty) {
         val cpy = sym.copySymDenotation()
-        cpy.filterAnnotations(_.symbol.hasAnnotation(metaAnnotSym))
+        cpy.filterAnnotations(annot => annot.hasOneOfMetaAnnotation(metaAnnotSym))
         cpy.installAfter(thisPhase)
       }
 
@@ -183,7 +178,6 @@ class Memoize extends MiniPhase with IdentityDenotTransformer { thisPhase =>
             if isErasableBottomField(field, rhsClass) then erasedBottomTree(rhsClass)
             else transformFollowingDeep(ref(field))(using ctx.withOwner(sym))
           val getterDef = cpy.DefDef(tree)(rhs = getterRhs)
-          addAnnotations(fieldDef.denot)
           removeUnwantedAnnotations(sym, defn.GetterMetaAnnot)
           Thicket(fieldDef, getterDef)
       else if sym.isSetter then

compiler/src/dotty/tools/dotc/transform/Pickler.scala

@@ -1,4 +1,5 @@
-package dotty.tools.dotc
+package dotty.tools
+package dotc
 package transform
 
 import core._
@@ -147,6 +148,7 @@ class Pickler extends Phase {
     if unequal then
       output("before-pickling.txt", previous)
       output("after-pickling.txt", unpickled)
+      //sys.process.Process("diff -u before-pickling.txt after-pickling.txt").!
       report.error(em"""pickling difference for $cls in ${cls.source}, for details:
                     |
                     |  diff before-pickling.txt after-pickling.txt""")

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -1,4 +1,5 @@
-package dotty.tools.dotc
+package dotty.tools
+package dotc
 package transform
 
 import dotty.tools.dotc.ast.{Trees, tpd, untpd, desugar}
@@ -186,12 +187,8 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
     private def removeUnwantedAnnotations(sym: Symbol, metaAnnotSym: Symbol,
         metaAnnotSymBackup: Symbol, keepIfNoRelevantAnnot: Boolean)(using Context): Unit =
       def shouldKeep(annot: Annotation): Boolean =
-        val annotSym = annot.symbol
-        annotSym.hasAnnotation(metaAnnotSym)
-          || annotSym.hasAnnotation(metaAnnotSymBackup)
-          || (keepIfNoRelevantAnnot && {
-            !annotSym.annotations.exists(metaAnnot => defn.FieldAccessorMetaAnnots.contains(metaAnnot.symbol))
-          })
+        annot.hasOneOfMetaAnnotation(metaAnnotSym, metaAnnotSymBackup)
+        || keepIfNoRelevantAnnot && !annot.hasOneOfMetaAnnotation(defn.NonBeanMetaAnnots.toList*)
       if sym.annotations.nonEmpty then
         sym.filterAnnotations(shouldKeep(_))
 

compiler/src/dotty/tools/dotc/transform/SymUtils.scala

@@ -271,7 +271,7 @@ object SymUtils:
       self.isAllOf(EnumCase, butNot = JavaDefined)
 
     def annotationsCarrying(meta: ClassSymbol)(using Context): List[Annotation] =
-      self.annotations.filter(_.symbol.hasAnnotation(meta))
+      self.annotations.filter(_.hasOneOfMetaAnnotation(meta))
 
     def withAnnotationsCarrying(from: Symbol, meta: ClassSymbol)(using Context): self.type = {
       self.addAnnotations(from.annotationsCarrying(meta))

compiler/src/dotty/tools/dotc/util/Spans.scala

@@ -182,6 +182,7 @@ object Spans {
       assert(isSpan)
       if (this == NoCoord) NoSpan else Span(-1 - encoding)
     }
+    override def toString = if isSpan then s"$toSpan" else s"Coord(idx=$toIndex)"
   }
 
   /** An index coordinate */

tests/run/beans.check

@@ -2,5 +2,6 @@
 true
 10
 [@beans.LibraryAnnotation_1()]
+[]
 some text
 other text

tests/run/beans/Test_3.java

@@ -7,6 +7,7 @@ public A run() throws ReflectiveOperationException{
     System.out.println(a.isY());
     System.out.println(new T2().getX());
 
+    System.out.println(Arrays.asList(a.getClass().getDeclaredField("retainingAnnotation").getAnnotations()));
     System.out.println(Arrays.asList(a.getClass().getMethod("getRetainingAnnotation").getAnnotations()));
 
     System.out.println(a.getMutableOneWithLongName());

tests/run/i12492.check

@@ -0,0 +1,37 @@
+inspecting constructor MyTable
+inspecting param aaaParam1 @MyColumnBase
+inspecting param fldParam1
+inspecting param getParam1
+inspecting param parParam1 @MyColumnBase
+inspecting field aaaField1 @MyColumnBase
+inspecting field aaaParam1
+inspecting field fldField1 @MyColumnBase
+inspecting field fldParam1 @MyColumnBase
+inspecting field getField1
+inspecting field getParam1
+inspecting field parField1
+inspecting field parParam1
+inspecting method aaaField1
+inspecting method aaaParam1
+inspecting method fldField1
+inspecting method fldParam1
+inspecting method getField1 @MyColumnBase
+inspecting method getParam1 @MyColumnBase
+inspecting method parField1
+inspecting method parParam1
+inspecting constructor MyTable2
+inspecting param fldParam2
+inspecting param getParam2
+inspecting param parParam2 @MyColumnBase
+inspecting field fldField2 @MyColumnBase
+inspecting field fldParam2 @MyColumnBase
+inspecting field getField2
+inspecting field getParam2
+inspecting field parField2
+inspecting field parParam2
+inspecting method fldField2
+inspecting method fldParam2
+inspecting method getField2 @MyColumnBase
+inspecting method getParam2 @MyColumnBase
+inspecting method parField2
+inspecting method parParam2

tests/run/i12492/MyColumnBase.java

@@ -0,0 +1,5 @@
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface MyColumnBase {}

tests/run/i12492/MyTable.scala

@@ -0,0 +1,27 @@
+import scala.annotation.meta.{ field as fld, getter as get, param as par }
+
+type FldColumn = MyColumnBase @fld
+type GetColumn = MyColumnBase @get
+type ParColumn = MyColumnBase @par
+
+class MyTable(
+  @(MyColumnBase     ) val aaaParam1: String,
+  @(MyColumnBase @fld) val fldParam1: String,
+  @(MyColumnBase @get) val getParam1: String,
+  @(MyColumnBase @par) val parParam1: String,
+) {
+  @(MyColumnBase     ) val aaaField1: String = ""
+  @(MyColumnBase @fld) val fldField1: String = ""
+  @(MyColumnBase @get) val getField1: String = ""
+  @(MyColumnBase @par) val parField1: String = ""
+}
+
+class MyTable2(
+  @FldColumn val fldParam2: String,
+  @GetColumn val getParam2: String,
+  @ParColumn val parParam2: String,
+) {
+  @FldColumn val fldField2: String = ""
+  @GetColumn val getField2: String = ""
+  @ParColumn val parField2: String = ""
+}

tests/run/i12492/Test.scala

@@ -0,0 +1,31 @@
+// scalajs: --skip
+object Test:
+  def main(args: Array[String]): Unit =
+    go(classOf[MyTable])
+    go(classOf[MyTable2])
+
+  def go(cls: Class[?]): Unit =
+    for c <- cls.getDeclaredConstructors.sortBy(_.getName) do
+      c.setAccessible(true)
+      println(s"inspecting constructor ${c.getName}")
+      for p <- c.getParameters.sortBy(_.getName) do
+        print(s"inspecting param ${p.getName}")
+        for a <- p.getAnnotations.sortBy(_.annotationType.toString) do
+          print(s" @${a.annotationType.getName}")
+        println()
+
+    for (m <- cls.getDeclaredFields.sortBy(_.getName)) {
+      m.setAccessible(true)
+      print(s"inspecting field ${m.getName}")
+      for a <- m.getAnnotations().sortBy(_.annotationType.toString) do
+        print(s" @${a.annotationType.getName}")
+      println()
+    }
+
+    for (m <- cls.getDeclaredMethods.sortBy(_.getName)) {
+      m.setAccessible(true)
+      print(s"inspecting method ${m.getName}")
+      for a <- m.getAnnotations().sortBy(_.annotationType.toString) do
+        print(s" @${a.annotationType.getName}")
+      println()
+    }

tests/run/i15318.check

@@ -0,0 +1,30 @@
+inspecting constructor Bean
+inspecting field beanAaa @JsonProperty
+inspecting field beanGet
+inspecting field beanSet
+inspecting field normAaa @JsonProperty
+inspecting field normFld @JsonProperty
+inspecting field normGet
+inspecting field normSet
+inspecting method beanAaa
+inspecting method beanGet
+inspecting method beanSet
+inspecting method beanSet_$eq
+inspecting method getBeanAaa
+inspecting method getBeanGet @JsonProperty
+inspecting method getBeanSet
+inspecting method normAaa
+inspecting method normFld
+inspecting method normGet @JsonProperty
+inspecting method normSet
+inspecting method normSet_$eq @JsonProperty
+inspecting method setBeanSet @JsonProperty
+inspecting constructor Bean2
+inspecting field beanGet
+inspecting field beanSet
+inspecting method beanGet
+inspecting method beanSet
+inspecting method beanSet_$eq
+inspecting method getBeanGet @JsonProperty
+inspecting method getBeanSet
+inspecting method setBeanSet @JsonProperty

tests/run/i15318/Bean.scala

@@ -0,0 +1,21 @@
+import scala.annotation.meta.{ field as fld, getter as get, setter as set, * }
+import scala.beans.BeanProperty
+
+type BeanGetJsonProperty = JsonProperty @beanGetter
+type BeanSetJsonProperty = JsonProperty @beanSetter
+
+class Bean {
+  @(JsonProperty     ) val normAaa: String = ""
+  @(JsonProperty @fld) val normFld: String = ""
+  @(JsonProperty @get) val normGet: String = ""
+  @(JsonProperty @set) var normSet: String = ""
+
+  @(JsonProperty            ) @BeanProperty val beanAaa: String = ""
+  @(JsonProperty @beanGetter) @BeanProperty val beanGet: String = ""
+  @(JsonProperty @beanSetter) @BeanProperty var beanSet: String = ""
+}
+
+class Bean2 {
+  @BeanGetJsonProperty @BeanProperty val beanGet: String = ""
+  @BeanSetJsonProperty @BeanProperty var beanSet: String = ""
+}

tests/run/i15318/JsonProperty.java

@@ -0,0 +1,5 @@
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface JsonProperty {}