SI-7582 ClassfileParser: populate privateWithin of Java module class

The `privateWithin` attribute of Java companion module classes was
correctly set under joint compilation (ie, when using JavaParser),
but not under separate compilation.

This commit remedies this. The test covers variety of Java symbols.

4 files changed, 43 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index cbfe5460f6..4c0c16690f 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -517,7 +517,7 @@ abstract class ClassfileParser {
     skipMembers() // methods
     if (!isScala) {
       clazz setFlag sflags
-      propagatePackageBoundary(jflags, clazz, staticModule)
+      propagatePackageBoundary(jflags, clazz, staticModule, staticModule.moduleClass)
       clazz setInfo classInfo
       moduleClass setInfo staticInfo
       staticModule setInfo moduleClass.tpe
diff --git a/test/files/run/t7582-private-within.check b/test/files/run/t7582-private-within.check
new file mode 100644
index 0000000000..b2743ffa06
--- /dev/null
+++ b/test/files/run/t7582-private-within.check
@@ -0,0 +1,12 @@
+private[package pack] class JavaPackagePrivate
+private[package pack] module JavaPackagePrivate
+private[package pack] module class JavaPackagePrivate
+private[package pack] field field
+private[package pack] primary constructor <init>
+private[package pack] method meth
+private[package pack] field staticField
+private[package pack] method staticMeth
+private[package pack] method <clinit>
+private[package pack] field staticField
+private[package pack] method staticMeth
+private[package pack] method <clinit>
diff --git a/test/files/run/t7582-private-within/JavaPackagePrivate.java b/test/files/run/t7582-private-within/JavaPackagePrivate.java
new file mode 100644
index 0000000000..672d19b57e
--- /dev/null
+++ b/test/files/run/t7582-private-within/JavaPackagePrivate.java
@@ -0,0 +1,8 @@
+package pack;
+
+class JavaPackagePrivate {
+	int field = 0;
+	static int staticField = 0;
+	void meth() { }
+	static void staticMeth() { }
+}
diff --git a/test/files/run/t7582-private-within/Test.scala b/test/files/run/t7582-private-within/Test.scala
new file mode 100644
index 0000000000..3d581f063b
--- /dev/null
+++ b/test/files/run/t7582-private-within/Test.scala
@@ -0,0 +1,22 @@
+import scala.tools.partest.DirectTest
+
+// Testing that the `privateWithin` field is correctly populated on all
+// the related symbols (e.g. module class) under separate compilation.
+object Test extends DirectTest {
+  def code = ???
+
+  def show(): Unit = {
+    val classpath = List(sys.props("partest.lib"), testOutput.path) mkString sys.props("path.separator")
+    val global = newCompiler("-usejavacp", "-cp", classpath, "-d", testOutput.path)
+    import global._
+    withRun(global) { _ =>
+      def check(sym: Symbol) = {
+        sym.initialize
+        println(f"${sym.accessString}%12s ${sym.accurateKindString} ${sym.name.decode}") // we want to see private[pack] for all of these.
+      }
+      val sym = rootMirror.getRequiredClass("pack.JavaPackagePrivate")
+      val syms = Seq(sym, sym.companionModule, sym.companionModule.moduleClass)
+      (syms ++ syms.flatMap(_.info.decls)).foreach(check)
+    }
+  }
+}