8294461: wrong effectively final determination by javac

Reviewed-by: vromero

Author: archiecobbs

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java

@@ -2006,14 +2006,13 @@ void newVar(JCVariableDecl varDecl) {
         void letInit(DiagnosticPosition pos, VarSymbol sym) {
             if (sym.adr >= firstadr && trackable(sym)) {
                 if ((sym.flags() & EFFECTIVELY_FINAL) != 0) {
-                    if (!uninits.isMember(sym.adr)) {
-                        //assignment targeting an effectively final variable
-                        //makes the variable lose its status of effectively final
-                        //if the variable is _not_ definitively unassigned
+                    if (inits.isMember(sym.adr) || !uninits.isMember(sym.adr)) {
+                        //assignment targeting an effectively final variable makes the
+                        //variable lose its status of effectively final if the variable
+                        //is definitely assigned or _not_ definitively unassigned
                         sym.flags_field &= ~EFFECTIVELY_FINAL;
-                    } else {
-                        uninit(sym);
                     }
+                    uninit(sym);
                 }
                 else if ((sym.flags() & FINAL) != 0) {
                     if ((sym.flags() & PARAMETER) != 0) {

test/langtools/tools/javac/lambda/8294461/EffectivelyFinalLoopIncrement.java

@@ -0,0 +1,14 @@
+/*
+ * @test /nodynamiccopyright/
+ * @summary Verify for() loop variable not effectively final even if loop never increments
+ * @bug 8294461
+ * @compile/fail/ref=EffectivelyFinalLoopIncrement.out -XDrawDiagnostics EffectivelyFinalLoopIncrement.java
+ */
+class EffectivelyFinalLoopIncrement {
+    EffectivelyFinalLoopIncrement() {
+        for (int i = 0; i < 10; i++) {
+            Runnable r = () -> System.out.println(i);   // variable i is NOT effectively final
+            break;                                      // even though "i++" is never reached
+        }
+    }
+}

test/langtools/tools/javac/lambda/8294461/EffectivelyFinalLoopIncrement.out

@@ -0,0 +1,2 @@
+EffectivelyFinalLoopIncrement.java:10:51: compiler.err.cant.ref.non.effectively.final.var: i, (compiler.misc.lambda)
+1 error