8329595: spurious variable "might not have been initialized" on static final field

Reviewed-by: vromero

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

@@ -481,7 +481,6 @@ public class Flow {
         }
 
         // Do something with all static or non-static field initializers and initialization blocks.
-        // Note: This method also sends nested class definitions to the handler.
         protected void forEachInitializer(JCClassDecl classDef, boolean isStatic, Consumer<? super JCTree> handler) {
             if (classDef == initScanClass)          // avoid infinite loops
                 return;
@@ -490,6 +489,11 @@ public class Flow {
             try {
                 for (List<JCTree> defs = classDef.defs; defs.nonEmpty(); defs = defs.tail) {
                     JCTree def = defs.head;
+
+                    // Don't recurse into nested classes
+                    if (def.hasTag(CLASSDEF))
+                        continue;
+
                     /* we need to check for flags in the symbol too as there could be cases for which implicit flags are
                      * represented in the symbol but not in the tree modifiers as they were not originally in the source
                      * code
@@ -566,6 +570,13 @@ public class Flow {
             lint = lint.augment(tree.sym);
 
             try {
+                // process all the nested classes
+                for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
+                    if (l.head.hasTag(CLASSDEF)) {
+                        scan(l.head);
+                    }
+                }
+
                 // process all the static initializers
                 forEachInitializer(tree, true, def -> {
                     scanDef(def);
@@ -1459,6 +1470,13 @@ public class Flow {
             lint = lint.augment(tree.sym);
 
             try {
+                // process all the nested classes
+                for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
+                    if (l.head.hasTag(CLASSDEF)) {
+                        scan(l.head);
+                    }
+                }
+
                 // process all the static initializers
                 forEachInitializer(tree, true, def -> {
                     scan(def);
@@ -2168,15 +2186,7 @@ public class Flow {
 
         @Override
         protected void markDead() {
-            if (!isConstructor) {
-                inits.inclRange(returnadr, nextadr);
-            } else {
-                for (int address = returnadr; address < nextadr; address++) {
-                    if (!(isFinalUninitializedStaticField(vardecls[address].sym))) {
-                        inits.incl(address);
-                    }
-                }
-            }
+            inits.inclRange(returnadr, nextadr);
             uninits.inclRange(returnadr, nextadr);
         }
 
@@ -2198,10 +2208,6 @@ public class Flow {
                    classDef.sym.isEnclosedBy((ClassSymbol)sym.owner));
         }
 
-        boolean isFinalUninitializedStaticField(VarSymbol sym) {
-            return isFinalUninitializedField(sym) && sym.isStatic();
-        }
-
         /** Initialize new trackable variable by setting its address field
          *  to the next available sequence number and entering it under that
          *  index into the vars array.
@@ -2420,7 +2426,7 @@ public class Flow {
                         clearPendingExits(false);
                     });
 
-                    // verify all static final fields got initailized
+                    // verify all static final fields got initialized
                     for (int i = firstadr; i < nextadr; i++) {
                         JCVariableDecl vardecl = vardecls[i];
                         VarSymbol var = vardecl.sym;
@@ -2448,6 +2454,13 @@ public class Flow {
                             scan(l.head);
                         }
                     }
+
+                    // process all the nested classes
+                    for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
+                        if (l.head.hasTag(CLASSDEF)) {
+                            scan(l.head);
+                        }
+                    }
                 } finally {
                     pendingExits = pendingExitsPrev;
                     nextadr = nextadrPrev;

test/langtools/tools/javac/DefiniteAssignment/StaticFinalNestedClass.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8329595
+ * @summary Verify spurious "might not have been initialized" error on static final field
+ * @run main StaticFinalNestedClass
+ */
+public class StaticFinalNestedClass {
+    public class Inner {                    // note this inner class is NOT static
+        public static final String NAME;
+        static {
+            try {
+                NAME = "bob";
+            } catch (Exception e) {
+                throw new Error(e);
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        new StaticFinalNestedClass().new Inner();
+    }
+}