Fix #1441: init MODULE$ in <clinit>

.github/workflows/ci.yaml

@@ -15,6 +15,9 @@ jobs:
     container: lampepfl/dotty:2020-04-24
 
     steps:
+      - name: Set JDK 11 as default
+        run: echo "::add-path::/usr/lib/jvm/java-11-openjdk-amd64/bin"
+
       - name: Checkout cleanup script
         uses: actions/checkout@v2
 
@@ -55,6 +58,9 @@ jobs:
     container: lampepfl/dotty:2020-04-24
 
     steps:
+      - name: Set JDK 11 as default
+        run: echo "::add-path::/usr/lib/jvm/java-11-openjdk-amd64/bin"
+
       - name: Checkout cleanup script
         uses: actions/checkout@v2
 
@@ -174,7 +180,7 @@ jobs:
       - name: Test
         run: ./project/scripts/sbt sbt-dotty/scripted
 
-  test_java11:
+  test_java8:
     runs-on: self-hosted
     container: lampepfl/dotty:2020-04-24
     if: (
@@ -184,6 +190,9 @@ jobs:
         github.event_name == 'schedule'
 
     steps:
+      - name: Set JDK 8 as default
+        run: echo "::add-path::/usr/lib/jvm/java-1.8.0-openjdk-amd64/bin"
+
       - name: Checkout cleanup script
         uses: actions/checkout@v2
 
@@ -215,14 +224,12 @@ jobs:
           restore-keys: ${{ runner.os }}-general-
 
       - name: Test
-        run: |
-          export PATH="/usr/lib/jvm/java-11-openjdk-amd64/bin:$PATH"
-          ./project/scripts/sbt ";compile ;test"
+        run: ./project/scripts/sbt ";compile ;test"
 
   publish_nightly:
     runs-on: self-hosted
     container: lampepfl/dotty:2020-04-24
-    needs: [test, test_bootstrapped, community_build, test_sbt, test_java11]
+    needs: [test, test_bootstrapped, community_build, test_sbt, test_java8]
     if: github.event_name == 'schedule'
     env:
       NIGHTLYBUILD: yes
@@ -323,7 +330,7 @@ jobs:
   publish_release:
     runs-on: self-hosted
     container: lampepfl/dotty:2020-04-24
-    needs: [test, test_bootstrapped, community_build, test_sbt, test_java11]
+    needs: [test, test_bootstrapped, community_build, test_sbt, test_java8]
     if: github.event_name == 'push' &&
         startsWith(github.event.ref, 'refs/tags/') &&
         !startsWith(github.event.ref, 'refs/tags/sbt-dotty-')
@@ -475,7 +482,7 @@ jobs:
   publish_sbt_release:
     runs-on: self-hosted
     container: lampepfl/dotty:2020-04-24
-    needs: [test, test_bootstrapped, community_build, test_sbt, test_java11]
+    needs: [test, test_bootstrapped, community_build, test_sbt, test_java8]
     if: github.event_name == 'push' &&
         startsWith(github.event.ref, 'refs/tags/sbt-dotty-')
 

compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala

@@ -364,9 +364,13 @@ trait BCodeBodyBuilder extends BCodeSkelBuilder {
           }
           else {
             mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
-            generatedType =
-              if (tree.symbol == defn.ArrayClass) ObjectReference
-              else classBTypeFromSymbol(claszSymbol)
+            // When compiling Array.scala, the constructor invokes `Array.this.super.<init>`. The expectedType
+            // is `[Object` (computed by typeToBType, the type of This(Array) is `Array[T]`). If we would set
+            // the generatedType to `Array` below, the call to adapt at the end would fail. The situation is
+            // similar for primitives (`I` vs `Int`).
+            if (tree.symbol != defn.ArrayClass && !tree.symbol.isPrimitiveValueClass) {
+              generatedType = classBTypeFromSymbol(claszSymbol)
+            }
           }
 
         case DesugaredSelect(Ident(nme.EMPTY_PACKAGE), module) =>
@@ -710,33 +714,18 @@ trait BCodeBodyBuilder extends BCodeSkelBuilder {
             if (t.symbol ne defn.Object_synchronized) genTypeApply(t)
             else genSynchronized(app, expectedType)
 
-        case Apply(fun @ DesugaredSelect(Super(_, _), _), args) =>
-          def initModule(): Unit = {
-            // we initialize the MODULE$ field immediately after the super ctor
-            if (!isModuleInitialized &&
-              jMethodName == INSTANCE_CONSTRUCTOR_NAME &&
-              fun.symbol.javaSimpleName == INSTANCE_CONSTRUCTOR_NAME &&
-              claszSymbol.isStaticModuleClass) {
-              isModuleInitialized = true
-              mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
-              mnode.visitFieldInsn(
-                asm.Opcodes.PUTSTATIC,
-                thisName,
-                str.MODULE_INSTANCE_FIELD,
-                "L" + thisName + ";"
-              )
-            }
-          }
+        case Apply(fun @ DesugaredSelect(Super(superQual, _), _), args) =>
           // 'super' call: Note: since constructors are supposed to
           // return an instance of what they construct, we have to take
           // special care. On JVM they are 'void', and Scala forbids (syntactically)
           // to call super constructors explicitly and/or use their 'returned' value.
           // therefore, we can ignore this fact, and generate code that leaves nothing
           // on the stack (contrary to what the type in the AST says).
-          mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
+
+          // scala/bug#10290: qual can be `this.$outer()` (not just `this`), so we call genLoad (not just ALOAD_0)
+          genLoad(superQual)
           genLoadArguments(args, paramTKs(app))
           generatedType = genCallMethod(fun.symbol, InvokeStyle.Super, app.span)
-          initModule()
 
         // 'new' constructor call: Note: since constructors are
         // thought to return an instance of what they construct,

compiler/src/dotty/tools/backend/jvm/BCodeIdiomatic.scala

@@ -29,6 +29,7 @@ trait BCodeIdiomatic {
     case "jvm-1.6"     => asm.Opcodes.V1_6
     case "jvm-1.7"     => asm.Opcodes.V1_7
     case "jvm-1.8"     => asm.Opcodes.V1_8
+    case "jvm-9"       => asm.Opcodes.V9
   }
 
   lazy val majorVersion: Int = (classfileVersion & 0xFF)