[Java 25] Bogus error: The blank final field o may not have been

initialized

* Fixes eclipse-jdt#4416

Author: srikanth-sankaran

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/ast/ConstructorDeclaration.java

@@ -89,9 +89,10 @@ public void analyseCode(ClassScope classScope, InitializationFlowContext initial
 public void analyseCode(ClassScope classScope, InitializationFlowContext initializerFlowContext, FlowInfo flowInfo, int initialReachMode, AnalysisMode mode) {
 	// Effect of 'AnalysisMode mode':
 	// ALL: 		analyse in one go as normal.
-	// PROLOGUE:	analyse only statements *before* the explicit constructor call (if any)
-	// REST:		analyse only starting with the explicit constructor call, if none present behaves like ALL
+	// PROLOGUE:	analyse only statements up-to the explicit constructor call (arguments of this call are technically prologue, too)
+	// REST:		analyse only statements after the explicit constructor call
 	// FlowContext and FlowInfo produced during PROLOGUE will be held in fields prologueContext and prologueInfo for use during REST
+	// prologueInfo is furthermore assumed to happen *before* any field initializers, see its use in TypeDeclaration.internalAnalyseCode()
 	if (this.ignoreFurtherInvestigation)
 		return;
 
@@ -215,15 +216,15 @@ public void analyseCode(ClassScope classScope, InitializationFlowContext initial
 				flowInfo = this.constructorCall.analyseCode(this.scope, constructorContext, flowInfo);
 				if (mode == AnalysisMode.PROLOGUE && hasArgumentNeedingAnalysis)
 					this.prologueInfo = flowInfo.copy();
-				// if calling 'this(...)', then flag all non-static fields as definitely
-				// set since they are supposed to be set inside other local constructor
-				if (this.constructorCall.accessMode == ExplicitConstructorCall.This) {
-					FieldBinding[] fields = this.binding.declaringClass.fields();
-					for (FieldBinding field : fields) {
-						if (!field.isStatic()) {
-							flowInfo.markAsDefinitelyAssigned(field);
-						}
-					}
+			}
+		}
+		if (this.constructorCall != null && this.constructorCall.accessMode == ExplicitConstructorCall.This) {
+			// if calling 'this(...)', then flag all non-static fields as definitely
+			// set since they are supposed to be set inside other local constructor
+			FieldBinding[] fields = this.binding.declaringClass.fields();
+			for (FieldBinding field : fields) {
+				if (!field.isStatic()) {
+					flowInfo.markAsDefinitelyAssigned(field);
 				}
 			}
 		}

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/InitializationTests.java

@@ -18,11 +18,15 @@
 
 import java.util.Map;
 import junit.framework.Test;
+import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
 
 @SuppressWarnings({ "unchecked", "rawtypes" })
 public class InitializationTests extends AbstractRegressionTest {
 
+static {
+//	TESTS_NAMES = new String [] { "testIssue4416" };
+}
 public InitializationTests(String name) {
 		super(name);
 }
@@ -487,6 +491,93 @@ public void testBug383690() {
 		"The blank final field oStatic may not have been initialized\n" +
 		"----------\n");
 }
+// https://github.com/eclipse-jdt/eclipse.jdt.core/issues/4416
+// Bogus error: The blank final field o may not have been initialized
+public void testIssue4416() {
+	runConformTest(new String[] {
+			"WrongNotInitialized.java",
+			"""
+			public class WrongNotInitialized {
+			  private final Object o;
+
+			  public WrongNotInitialized(final Object o) {
+			    super();
+			    this.o = o;
+			  }
+
+			  public WrongNotInitialized() {
+			    this(new Object());
+			    System.out.println(o.toString());
+			  }
+			}
+			"""
+	});
+}
+// https://github.com/eclipse-jdt/eclipse.jdt.core/issues/4416
+// Bogus error: The blank final field o may not have been initialized
+public void testIssue4416b() {
+	runConformTest(new String[] {
+			"Test.java",
+			"""
+			public class Test {
+
+				final int x;
+
+				Test(int x) {
+					this.x = x;
+				}
+
+				Test(Test a) {
+					this(a.x);
+					//this(1);
+
+					System.out.println(x);
+				}
+			}
+			"""
+	});
+}
+// https://github.com/eclipse-jdt/eclipse.jdt.core/issues/4416
+// Bogus error: The blank final field o may not have been initialized
+public void testIssue4416c() {
+	if (this.complianceLevel < ClassFileConstants.JDK16)
+		return;
+	runConformTest(new String[] {
+			"TestRecord.java",
+			"""
+			public record TestRecord(String a)
+			{
+			    public TestRecord(int b)
+			    {
+			        this(String.valueOf(b));
+			        System.out.println(a.length());
+			    }
+			}
+			"""
+	});
+}
+// https://github.com/eclipse-jdt/eclipse.jdt.core/issues/4416
+// Bogus error: The blank final field o may not have been initialized
+public void testIssue4416d() {
+	runConformTest(new String[] {
+			"Test.java",
+			"""
+			public class Test {
+
+			        private final Object r;
+
+			        Test() {
+			                this(Integer.valueOf(1));
+			                r.hashCode();
+			        }
+
+			        Test(Object r) {
+			                this.r = r;
+			        }
+			}
+			"""
+	});
+}
 public static Class testClass() {
 	return InitializationTests.class;
 }