SI-7501 Pickler: owner adjustment for param syms in annotation args

Pickling of trees within annotation arguments led to an unfortunate
situation: the MethodType of a symbol contained a value parameter
symbol that was pickled as though it were owned by the enclosing
class (the root symbol of the pickle.)

Under separate compilation, this would appear as a member of that
class.

Anyone using `@deprecatedName('oldName)` was exposed to this problem,
as the argument expands to `Symbol.apply("oldName")`.

This commit extends some similar treatment of local type parameters
to also consider value parameters.

4 files changed, 30 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala b/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
index 9bad29097c..9ac1ce1b9c 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
@@ -88,12 +88,17 @@ abstract class Pickler extends SubComponent {
     /** Returns usually symbol's owner, but picks classfile root instead
      *  for existentially bound variables that have a non-local owner.
      *  Question: Should this be done for refinement class symbols as well?
+     *
+     *  Note: tree pickling also finds its way here; e.g. in SI-7501 the pickling
+     *  of trees in annotation arguments considers the parameter symbol of a method
+     *  called in such a tree as "local". The condition `sym.isValueParameter` was
+     *  added to fix that bug, but there may be a better way.
      */
     private def localizedOwner(sym: Symbol) =
       if (isLocal(sym) && !isRootSym(sym) && !isLocal(sym.owner))
         // don't use a class as the localized owner for type parameters that are not owned by a class: those are not instantiated by asSeenFrom
         // however, they would suddenly be considered by asSeenFrom if their localized owner became a class (causing the crashes of #4079, #2741)
-        (if(sym.isTypeParameter && !sym.owner.isClass) nonClassRoot
+        (if ((sym.isTypeParameter || sym.isValueParameter) && !sym.owner.isClass) nonClassRoot
          else root)
       else sym.owner
 
diff --git a/test/files/neg/t7501.check b/test/files/neg/t7501.check
new file mode 100644
index 0000000000..2ded07c7ed
--- /dev/null
+++ b/test/files/neg/t7501.check
@@ -0,0 +1,7 @@
+t7501_2.scala:2: error: value name is not a member of A
+  def foo(a: A) = a.name
+                    ^
+t7501_2.scala:4: error: not found: type X
+  type TP = X // already failed before this fix
+            ^
+two errors found
diff --git a/test/files/neg/t7501/t7501_1.scala b/test/files/neg/t7501/t7501_1.scala
new file mode 100644
index 0000000000..323c327623
--- /dev/null
+++ b/test/files/neg/t7501/t7501_1.scala
@@ -0,0 +1,12 @@
+object Test2 {
+ def test[X](name: String) = 12
+}
+class strangeTest(x: Int) extends scala.annotation.StaticAnnotation
+
+trait A {
+  // When picking the type of `test`, the value parameter
+  // `x` was pickled with the owner `trait A`. On unpickling,
+  // it was taken to be a member!
+  @strangeTest(Test2.test("test"))
+  def test(x: String): Unit
+}
diff --git a/test/files/neg/t7501/t7501_2.scala b/test/files/neg/t7501/t7501_2.scala
new file mode 100644
index 0000000000..044caea3c3
--- /dev/null
+++ b/test/files/neg/t7501/t7501_2.scala
@@ -0,0 +1,5 @@
+object Test {
+  def foo(a: A) = a.name
+
+  type TP = X // already failed before this fix
+}