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SI-6375, warn on lost annotation.

Annotations on abstract vals which are not meta-annotated
were silently discarded. Still discarded, only less silently.
I warned on as many "lost annotation" situations as I was
reasonably able to cover without false positives.
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1 parent ebdc0ff commit 61f70e48cecddf27fba162c165dfaf712c84278c @paulp paulp committed Jan 14, 2013
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35 src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
@@ -126,7 +126,7 @@ trait MethodSynthesis {
/** There are two key methods in here.
*
- * 1) Enter methods such as enterGetterSetterare called
+ * 1) Enter methods such as enterGetterSetter are called
* from Namer with a tree which may generate further trees such as accessors or
* implicit wrappers. Some setup is performed. In general this creates symbols
* and enters them into the scope of the owner.
@@ -171,14 +171,45 @@ trait MethodSynthesis {
enterBeans(tree)
}
+ /** This is called for those ValDefs which addDerivedTrees ignores, but
+ * which might have a warnable annotation situation.
+ */
+ private def warnForDroppedAnnotations(tree: Tree) {
+ val annotations = tree.symbol.initialize.annotations
+ val targetClass = defaultAnnotationTarget(tree)
+ val retained = deriveAnnotations(annotations, targetClass, keepClean = true)
+
+ annotations filterNot (retained contains _) foreach (ann => issueAnnotationWarning(ann, targetClass))
+ }
+ private def issueAnnotationWarning(ann: AnnotationInfo, defaultTarget: Symbol) {
+ global.reporter.warning(ann.pos,
+ s"Annotation is unused - it can be retained with a meta-annotation such as @($ann @${defaultTarget.name})")
+ }
+
def addDerivedTrees(typer: Typer, stat: Tree): List[Tree] = stat match {
case vd @ ValDef(mods, name, tpt, rhs) if !noFinishGetterSetter(vd) =>
// If we don't save the annotations, they seem to wander off.
val annotations = stat.symbol.initialize.annotations
- ( allValDefDerived(vd)
+ val trees = (
+ allValDefDerived(vd)
map (acc => atPos(vd.pos.focus)(acc derive annotations))
filterNot (_ eq EmptyTree)
)
+ // Verify each annotation landed safely somewhere, else warn.
+ // Filtering when isParamAccessor is a necessary simplification
+ // because there's a bunch of unwritten annotation code involving
+ // the propagation of annotations - constructor parameter annotations
+ // may need to make their way to parameters of the constructor as
+ // well as fields of the class, etc.
+ if (!mods.isParamAccessor) annotations foreach (ann =>
+ if (!trees.exists(_.symbol hasAnnotation ann.symbol))
+ issueAnnotationWarning(ann, GetterTargetClass)
+ )
+
+ trees
+ case vd: ValDef =>
+ warnForDroppedAnnotations(vd)
+ vd :: Nil
case cd @ ClassDef(mods, _, _, _) if mods.isImplicit =>
val annotations = stat.symbol.initialize.annotations
// TODO: need to shuffle annotations between wrapper and class.
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27 test/files/neg/t6375.check
@@ -0,0 +1,27 @@
+t6375.scala:6: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @getter)
+ @Bippy val x1: Int // warn
+ ^
+t6375.scala:7: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.field @getter)
+ @(Bippy @field) val x2: Int // warn
+ ^
+t6375.scala:9: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.setter @getter)
+ @(Bippy @setter) val x4: Int // warn
+ ^
+t6375.scala:10: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.param @getter)
+ @(Bippy @param) val x5: Int // warn
+ ^
+t6375.scala:20: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.getter @field)
+ @(Bippy @getter) private[this] val q1: Int = 1 // warn
+ ^
+t6375.scala:40: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.getter @param)
+ @(Bippy @getter) p2: Int, // warn
+ ^
+t6375.scala:41: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.setter @param)
+ @(Bippy @setter) p3: Int, // warn
+ ^
+t6375.scala:42: warning: Annotation is unused - it can be retained with a meta-annotation such as @(Bippy @scala.annotation.meta.field @param)
+ @(Bippy @field) p4: Int // warn
+ ^
+error: No warnings can be incurred under -Xfatal-warnings.
+8 warnings found
+one error found
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1 test/files/neg/t6375.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
View
67 test/files/neg/t6375.scala
@@ -0,0 +1,67 @@
+import scala.annotation.meta._
+
+class Bippy extends scala.annotation.StaticAnnotation
+
+abstract class Foo {
+ @Bippy val x1: Int // warn
+ @(Bippy @field) val x2: Int // warn
+ @(Bippy @getter) val x3: Int // no warn
+ @(Bippy @setter) val x4: Int // warn
+ @(Bippy @param) val x5: Int // warn
+}
+
+object Bar extends Foo {
+ val x1 = 1
+ val x2 = 2
+ val x3 = 3
+ val x4 = 4
+ val x5 = 5
+
+ @(Bippy @getter) private[this] val q1: Int = 1 // warn
+ @(Bippy @getter) private val q2: Int = 1 // no warn
+
+ def f1(@(Bippy @param) x: Int): Int = 0 // no warn
+ def f2(@(Bippy @getter) x: Int): Int = 0 // warn - todo
+ def f3(@(Bippy @setter) x: Int): Int = 0 // warn - todo
+ def f4(@(Bippy @field) x: Int): Int = 0 // warn - todo
+ def f5(@Bippy x: Int): Int = 0 // no warn
+
+ @(Bippy @companionClass) def g1(x: Int): Int = 0 // warn - todo
+ @(Bippy @companionObject) def g2(x: Int): Int = 0 // warn - todo
+ @(Bippy @companionMethod) def g3(x: Int): Int = 0 // no warn
+ @Bippy def g4(x: Int): Int = 0 // no warn
+
+ @(Bippy @companionObject @companionMethod) def g5(x: Int): Int = 0 // no warn
+}
+
+class Dingo(
+ @Bippy p0: Int, // no warn
+ @(Bippy @param) p1: Int, // no warn
+ @(Bippy @getter) p2: Int, // warn
+ @(Bippy @setter) p3: Int, // warn
+ @(Bippy @field) p4: Int // warn
+)
+
+class ValDingo(
+ @Bippy val p0: Int, // no warn
+ @(Bippy @param) val p1: Int, // no warn
+ @(Bippy @getter) val p2: Int, // no warn
+ @(Bippy @setter) val p3: Int, // warn - todo
+ @(Bippy @field) val p4: Int // no warn
+)
+
+class VarDingo(
+ @Bippy var p0: Int, // no warn
+ @(Bippy @param) var p1: Int, // no warn
+ @(Bippy @getter) var p2: Int, // no warn
+ @(Bippy @setter) var p3: Int, // no warn
+ @(Bippy @field) var p4: Int // no warn
+)
+
+case class CaseDingo(
+ @Bippy p0: Int, // no warn
+ @(Bippy @param) p1: Int, // no warn
+ @(Bippy @getter) p2: Int, // no warn
+ @(Bippy @setter) p3: Int, // warn - todo
+ @(Bippy @field) p4: Int // no warn
+)

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