Support use-site meta-annotations

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

@@ -87,6 +87,19 @@ object Annotations {
     def sameAnnotation(that: Annotation)(using Context): Boolean =
       symbol == that.symbol && tree.sameTree(that.tree)
 
+    def hasOneOfMetaAnnotation(metaSyms: Symbol*)(using Context): Boolean =
+      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")

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.filter { a =>
+        a.hasOneOfMetaAnnotation(defn.BeanGetterMetaAnnot) | !a.hasOneOfMetaAnnotation(defn.BeanSetterMetaAnnot)
+      }
+      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 +51,11 @@ 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)
-        def body(params: List[List[Tree]]): Tree = Assign(ref(valDef.symbol), params.head.head)
-        DefDef(meth, body)
+        val annots = valDef.symbol.annotations.filter { a =>
+          a.hasOneOfMetaAnnotation(defn.BeanSetterMetaAnnot) | !a.hasOneOfMetaAnnotation(defn.BeanGetterMetaAnnot)
+        }
+        meth.addAnnotations(annots)
+        DefDef(meth, (params: List[List[Tree]]) => Assign(ref(valDef.symbol), params.head.head)).withSpan(meth.span)
       }
 
     def prefixedName(prefix: String, valName: Name) =

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.FieldAccessorMetaAnnots.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/i12492.check

@@ -0,0 +1,9 @@
+inspecting field brandName
+interface MyColumnBase
+inspecting field companyName
+interface MyColumnBase
+inspecting method brandName
+inspecting method companyName
+inspecting constructor MyTable
+inspecting param brandName
+inspecting param companyName

tests/run/i12492/MyColumnBase.java

@@ -0,0 +1,7 @@
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface MyColumnBase {
+    String name() default "";
+}

tests/run/i12492/MyTable.scala

@@ -0,0 +1,10 @@
+import scala.annotation.meta.field
+
+type MyColumn = MyColumnBase @field
+
+class MyTable(
+  @(MyColumnBase @field)(name="BRAND_NAME")
+  val brandName: String,
+  @MyColumn(name="COMPANY_NAME")
+  val companyName: String,
+)

tests/run/i12492/Test.scala

@@ -0,0 +1,26 @@
+// scalajs: --skip
+object Test:
+  def main(args: Array[String]): Unit =
+    val cls = classOf[MyTable]
+
+    for (m <- cls.getDeclaredFields.sortBy(_.getName)) {
+      m.setAccessible(true)
+      println(s"inspecting field ${m.getName}")
+      for a <- m.getAnnotations().sortBy(_.annotationType.toString) do
+        println(a.annotationType)
+    }
+
+    for (m <- cls.getDeclaredMethods.sortBy(_.getName)) {
+      m.setAccessible(true)
+      println(s"inspecting method ${m.getName}")
+      for a <- m.getAnnotations().sortBy(_.annotationType.toString) do
+        println(a.annotationType)
+    }
+
+    for c <- cls.getDeclaredConstructors.sortBy(_.getName) do
+      c.setAccessible(true)
+      println(s"inspecting constructor ${c.getName}")
+      for p <- c.getParameters.sortBy(_.getName) do
+        println(s"inspecting param ${p.getName}")
+        for a <- p.getAnnotations.sortBy(_.annotationType.toString) do
+          println(a.annotationType)

tests/run/i15318.check

@@ -0,0 +1,8 @@
+inspecting field value
+interface JsonProperty
+inspecting method getValue
+interface JsonProperty
+inspecting method setValue
+inspecting method value
+inspecting method value_$eq
+inspecting constructor TestBeanProperty

tests/run/i15318/JsonProperty.java

@@ -0,0 +1,7 @@
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface JsonProperty {
+    String value() default "";
+}

tests/run/i15318/Test.scala

@@ -0,0 +1,26 @@
+// scalajs: --skip
+object Test:
+  def main(args: Array[String]): Unit =
+    val cls = classOf[TestBeanProperty]
+
+    for (m <- cls.getDeclaredFields.sortBy(_.getName)) {
+      m.setAccessible(true)
+      println(s"inspecting field ${m.getName}")
+      for a <- m.getAnnotations().sortBy(_.annotationType.toString) do
+        println(a.annotationType)
+    }
+
+    for (m <- cls.getDeclaredMethods.sortBy(_.getName)) {
+      m.setAccessible(true)
+      println(s"inspecting method ${m.getName}")
+      for a <- m.getAnnotations().sortBy(_.annotationType.toString) do
+        println(a.annotationType)
+    }
+
+    for c <- cls.getDeclaredConstructors.sortBy(_.getName) do
+      c.setAccessible(true)
+      println(s"inspecting constructor ${c.getName}")
+      for p <- c.getParameters.sortBy(_.getName) do
+        println(s"inspecting param ${p.getName}")
+        for a <- p.getAnnotations.sortBy(_.annotationType.toString) do
+          println(a.annotationType)

tests/run/i15318/TestBeanProperty.scala

@@ -0,0 +1,10 @@
+import scala.annotation.meta.beanGetter
+import scala.beans.BeanProperty
+
+class TestBeanProperty {
+
+  @(JsonProperty @beanGetter)(value = "REAL_VALUE")
+  @BeanProperty
+  var value: String = _
+
+}