Allow separate compilation of Dotty using TASTY

Classfile parser now reads TASTY attributes or annotations and
unpickles them in order to allow for separate compilation.

Author: odersky

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

@@ -335,6 +335,8 @@ class Definitions {
   lazy val ContravariantBetweenClass = ctx.requiredClass("dotty.annotation.internal.ContravariantBetween")
   lazy val ScalaSignatureAnnot = ctx.requiredClass("scala.reflect.ScalaSignature")
   lazy val ScalaLongSignatureAnnot = ctx.requiredClass("scala.reflect.ScalaLongSignature")
+  lazy val TASTYSignatureAnnot = ctx.requiredClass("scala.annotation.internal.TASTYSignature")
+  lazy val TASTYLongSignatureAnnot = ctx.requiredClass("scala.annotation.internal.TASTYLongSignature")
   lazy val DeprecatedAnnot = ctx.requiredClass("scala.deprecated")
   lazy val MigrationAnnot = ctx.requiredClass("scala.annotation.migration")
   lazy val AnnotationDefaultAnnot = ctx.requiredClass("dotty.annotation.internal.AnnotationDefault")

src/dotty/tools/dotc/core/pickling/ClassfileParser.scala

@@ -664,11 +664,17 @@ class ClassfileParser(
         i < attrs
       }
 
-      def unpickle(bytes: Array[Byte]): Boolean = {
+      def unpickleScala(bytes: Array[Byte]): Boolean = {
         new UnPickler(bytes, classRoot, moduleRoot)(ctx).run()
         true
       }
 
+      def unpickleTASTY(bytes: Array[Byte]): Boolean = {
+        new DottyUnpickler(bytes)
+          .enter(roots = Set(classRoot, moduleRoot, moduleRoot.sourceModule))
+        true
+      }
+
       def parseScalaSigBytes: Array[Byte] = {
         val tag = in.nextByte.toChar
         assert(tag == STRING_TAG, tag)
@@ -688,6 +694,11 @@ class ClassfileParser(
         pool.getBytes(entries.toList)
       }
 
+      if (scan(tpnme.TASTYATTR)) {
+        val attrLen = in.nextInt
+        return unpickleTASTY(in.nextBytes(attrLen))
+      }
+
       if (scan(tpnme.RuntimeAnnotationATTR)) {
         val attrLen = in.nextInt
         val nAnnots = in.nextChar
@@ -698,12 +709,16 @@ class ClassfileParser(
           var j = 0
           while (j < nArgs) {
             val argName = pool.getName(in.nextChar)
-            if (attrClass == defn.ScalaSignatureAnnot && argName == nme.bytes)
-              return unpickle(parseScalaSigBytes)
-            else if (attrClass == defn.ScalaLongSignatureAnnot && argName == nme.bytes)
-              return unpickle(parseScalaLongSigBytes)
-            else
-              parseAnnotArg(skip = true)
+            if (argName == nme.bytes)
+              if (attrClass == defn.ScalaSignatureAnnot)
+                return unpickleScala(parseScalaSigBytes)
+              else if (attrClass == defn.ScalaLongSignatureAnnot)
+                return unpickleScala(parseScalaLongSigBytes)
+              else if (attrClass == defn.TASTYSignatureAnnot)
+                return unpickleTASTY(parseScalaSigBytes)
+              else if (attrClass == defn.TASTYLongSignatureAnnot)
+                return unpickleTASTY(parseScalaLongSigBytes)
+            parseAnnotArg(skip = true)
             j += 1
           }
           i += 1

src/scala/annotation/internal/TASTYLongSignature.java

@@ -0,0 +1,12 @@
+package scala.annotation.internal;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface TASTYLongSignature {
+    public String[] bytes();
+}

src/scala/annotation/internal/TASTYSignature.java

@@ -0,0 +1,12 @@
+package scala.annotation.internal;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface TASTYSignature {
+    public String bytes();
+}

tests/pos/sepComp/A_1.scala

@@ -0,0 +1,13 @@
+package sepComp
+
+class A(y: Int) {
+
+  val x: Int = y
+
+}
+
+object A {
+
+  def apply(x: Int) = new A(22)
+
+}

tests/pos/sepComp/B_2.scala

@@ -0,0 +1,13 @@
+package sepComp
+
+class B extends A(22) {
+
+  val y: Int = this.x
+
+  val a = A(33)
+
+  println(a.x)
+
+}
+
+