[24] don't request access to enclosing class if it's never used (#3390)

* [24] don't request access to enclosing class if it's never used

Fixes after re-opening:
+ essentially revert previous change
+ replace with specific detection wrt local type alloc in static context

Fixes #3194

* [24] don't request access to enclosing class if it's never used

+ additional test

Fixes #3194

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/core/compiler/IProblem.java

@@ -8,6 +8,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     IBM Corporation - added the following constants
@@ -2759,6 +2763,11 @@ public interface IProblem {
 	 */
 	int ConstructorCallNotAllowedHere = PreviewRelated + 2031;
 
+	/**
+	 * @since 3.40
+	 */
+	int AllocatingLocalInStaticContext = TypeRelated + 2032;
+
 	/**
 	 * @since 3.40
 	 * @noreference preview feature

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

@@ -8,6 +8,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Stephan Herrmann - Contributions for
@@ -363,6 +367,11 @@ public TypeBinding resolveType(BlockScope scope) {
 		} else {
 			this.resolvedType = this.type.resolveType(scope, true /* check bounds*/);
 		}
+		if (this.resolvedType instanceof LocalTypeBinding local && this.enumConstant == null) {
+			MethodScope enclosingMethodScope = local.scope.enclosingMethodScope();
+			if (enclosingMethodScope != null && !enclosingMethodScope.isStatic && scope.isInStaticContext())
+				scope.problemReporter().allocationInStaticContext(this, local);
+		}
 		if (this.type != null) {
 			checkIllegalNullAnnotation(scope, this.resolvedType);
 			checkParameterizedAllocation: {

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

@@ -12,6 +12,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Jesper S Moller - Contributions for
@@ -718,6 +722,12 @@ enclosing instance of this (8.1.3)", we will actually implement this check in co
         if (isMethodReference) {
         	someMethod = scope.getMethod(this.receiverType, this.selector, descriptorParameters, this);
         } else {
+        	if (this.receiverType instanceof LocalTypeBinding local) {
+        		MethodScope enclosingMethodScope = local.scope.enclosingMethodScope();
+        		if (enclosingMethodScope != null && !enclosingMethodScope.isStatic && scope.isInStaticContext()) {
+        			scope.problemReporter().allocationInStaticContext(this, local);
+        		}
+        	}
         	if (argumentsTypeElided() && this.receiverType.isRawType()) {
         		boolean[] inferredReturnType = new boolean[1];
 	        	someMethod = AllocationExpression.inferDiamondConstructor(scope, this, this.receiverType, this.descriptor.parameters, inferredReturnType);

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

@@ -8,6 +8,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Stephan Herrmann <stephan@cs.tu-berlin.de> - Contributions for
@@ -921,22 +925,18 @@ public void manageSyntheticAccessIfNecessary(BlockScope currentScope, FlowInfo f
 	if ((this.bits & Binding.FIELD) != 0) {
 		FieldBinding fieldBinding = (FieldBinding) this.binding;
 		FieldBinding codegenField = fieldBinding.original();
-		if ((this.bits & ASTNode.DepthMASK) != 0) {
-			if ((codegenField.isPrivate() // private access
-					&& !currentScope.enclosingSourceType().isNestmateOf(codegenField.declaringClass))
-					|| (codegenField.isProtected() // implicit protected access
-							&& codegenField.declaringClass.getPackage() != currentScope.enclosingSourceType().getPackage())) {
-				if (this.syntheticAccessors == null)
-					this.syntheticAccessors = new MethodBinding[2];
-				this.syntheticAccessors[isReadAccess ? SingleNameReference.READ : SingleNameReference.WRITE] =
-					((SourceTypeBinding) currentScope.enclosingSourceType().
-							enclosingTypeAt((this.bits & ASTNode.DepthMASK) >> ASTNode.DepthSHIFT)).addSyntheticMethod(codegenField, isReadAccess, false /* not super access */);
-				currentScope.problemReporter().needToEmulateFieldAccess(codegenField, this, isReadAccess);
-				return;
-			}
-			if (!codegenField.isStatic() && currentScope.enclosingSourceType() instanceof NestedTypeBinding nestedType) {
-				nestedType.requestEnclosingInstancePathTo(codegenField.declaringClass);
-			}
+		if (((this.bits & ASTNode.DepthMASK) != 0)
+			&& ((codegenField.isPrivate() // private access
+					&& !currentScope.enclosingSourceType().isNestmateOf(codegenField.declaringClass) )
+				|| (codegenField.isProtected() // implicit protected access
+						&& codegenField.declaringClass.getPackage() != currentScope.enclosingSourceType().getPackage()))) {
+			if (this.syntheticAccessors == null)
+				this.syntheticAccessors = new MethodBinding[2];
+			this.syntheticAccessors[isReadAccess ? SingleNameReference.READ : SingleNameReference.WRITE] =
+			    ((SourceTypeBinding)currentScope.enclosingSourceType().
+					enclosingTypeAt((this.bits & ASTNode.DepthMASK) >> ASTNode.DepthSHIFT)).addSyntheticMethod(codegenField, isReadAccess, false /*not super access*/);
+			currentScope.problemReporter().needToEmulateFieldAccess(codegenField, this, isReadAccess);
+			return;
 		}
 	}
 }

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

@@ -8,6 +8,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Stephan Herrmann - Contributions for
@@ -1072,14 +1076,9 @@ public void manageEnclosingInstanceAccessIfNecessary(BlockScope currentScope, Fl
 			outerScope = outerScope.enclosingInstanceScope();
 			earlySeen = methodScope.isInsideEarlyConstructionContext(nestedType.enclosingType(), false);
 		}
-		if (JavaFeature.FLEXIBLE_CONSTRUCTOR_BODIES.isSupported(currentScope.compilerOptions())
-				&& nestedType.enclosingInstances != null) // only if access to enclosing instance has already been requested
-		{
+		if (JavaFeature.FLEXIBLE_CONSTRUCTOR_BODIES.isSupported(currentScope.compilerOptions())) {
 			// JEP 482: this is the central location for organizing synthetic arguments and fields
 			// to serve far outer instances even in inner early construction context.
-			// Only SingleNameReference.manageSyntheticAccessIfNecessary() may add more synth outers later on
-			// (using NestedTypeBinding.requestEnclosingInstancePathTo()).
-			//
 			// Locations MethodBinding.computeSignature() and BlockScope.getEmulationPath() will faithfully
 			// use the information generated here, to decide about signature and call sequence.
 			while (outerScope != null) {

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/NestedTypeBinding.java

@@ -126,27 +126,14 @@ public SyntheticArgumentBinding addSyntheticArgumentAndField(ReferenceBinding ta
 	if (!isPrototype()) throw new IllegalStateException();
 	if (this.scope.isInsideEarlyConstructionContext(targetEnclosingType, false))
 		return null;
-	return doAddSyntheticArgumentAndField(targetEnclosingType);
-}
-
-private SyntheticArgumentBinding doAddSyntheticArgumentAndField(ReferenceBinding targetEnclosingType) {
 	SyntheticArgumentBinding synthLocal = addSyntheticArgument(targetEnclosingType);
-	if (synthLocal == null)
-		return null;
+	if (synthLocal == null) return null;
+
 	if (synthLocal.matchingField == null)
 		synthLocal.matchingField = addSyntheticFieldForInnerclass(targetEnclosingType);
 	return synthLocal;
 }
 
-public void requestEnclosingInstancePathTo(ReferenceBinding targetEnclosingClass) {
-	if (isCompatibleWith(targetEnclosingClass))
-		return;
-	if (getSyntheticField(targetEnclosingClass, false) == null)
-		doAddSyntheticArgumentAndField(targetEnclosingClass);
-	if (this.enclosingType instanceof NestedTypeBinding nestedType)
-		nestedType.requestEnclosingInstancePathTo(targetEnclosingClass);
-}
-
 /* Answer the receiver's enclosing type... null if the receiver is a top level type.
 */
 @Override

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/Scope.java

@@ -8,6 +8,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Stephan Herrmann - Contributions for
@@ -5797,6 +5801,11 @@ public List<ClassScope> collectClassesBeingInitialized() {
 		return list;
 	}
 
+	public boolean isInStaticContext() {
+		MethodScope methodScope = methodScope();
+		return methodScope != null && methodScope.isStatic;
+	}
+
 	public void include(LocalVariableBinding[] bindings) {
 		// `this` is assumed to be populated with bindings.
 		if (bindings != null) {

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java

@@ -8,6 +8,10 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  *
+ * This is an implementation of an early-draft specification developed under the Java
+ * Community Process (JCP) and is made available for testing and evaluation purposes
+ * only. The code is not compatible with any specification of the JCP.
+ *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Benjamin Muskalla - Contribution for bug 239066
@@ -12425,6 +12429,15 @@ public void allocationInEarlyConstructionContext(Expression expr, TypeBinding al
 		expr.sourceStart,
 		expr.sourceEnd);
 }
+public void allocationInStaticContext(ASTNode location, LocalTypeBinding allocatedType) {
+	this.handle(
+			IProblem.AllocatingLocalInStaticContext,
+			new String[] { String.valueOf(allocatedType.readableName()) },
+			new String[] { String.valueOf(allocatedType.shortReadableName()) },
+			location.sourceStart,
+			location.sourceEnd);
+}
+
 public void fieldReadInEarlyConstructionContext(char[] token, int sourceStart, int sourceEnd) {
 	String[] arguments = new String[] {String.valueOf(token)};
 	this.handle(

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/problem/messages.properties

@@ -1201,6 +1201,7 @@
 2029 = Cannot assign field ''{0}'' from class ''{1}'' in an early construction context
 2030 = Cannot assign field ''{0}'' in an early construction context, because it has an initializer
 2031 = Constructor call is not allowed here
+2032 = Cannot instantiate local class ''{0}'' in a static context
 
 # JEP 455 Primitive Types in Patterns, instanceof, and switch (Preview)
 2100 = Case constants in a switch on ''{0}'' must have type ''{1}''

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

@@ -342,6 +342,7 @@ class ProblemAttributes {
 		expectedProblemAttributes.put("AbstractMethodMustBeImplementedOverConcreteMethod", new ProblemAttributes(CategorizedProblem.CAT_MEMBER));
 		expectedProblemAttributes.put("AbstractMethodsInConcreteClass", new ProblemAttributes(CategorizedProblem.CAT_TYPE));
 		expectedProblemAttributes.put("AbstractServiceImplementation", new ProblemAttributes(CategorizedProblem.CAT_TYPE));
+		expectedProblemAttributes.put("AllocatingLocalInStaticContext", new ProblemAttributes(CategorizedProblem.CAT_TYPE));
 		expectedProblemAttributes.put("AmbiguousConstructor", new ProblemAttributes(CategorizedProblem.CAT_MEMBER));
 		expectedProblemAttributes.put("AmbiguousConstructorInDefaultConstructor", new ProblemAttributes(CategorizedProblem.CAT_MEMBER));
 		expectedProblemAttributes.put("AmbiguousConstructorInImplicitConstructorCall", new ProblemAttributes(CategorizedProblem.CAT_MEMBER));
@@ -1480,6 +1481,7 @@ class ProblemAttributes {
 		expectedProblemAttributes.put("AbstractMethodMustBeImplementedOverConcreteMethod", SKIP);
 		expectedProblemAttributes.put("AbstractMethodsInConcreteClass", SKIP);
 		expectedProblemAttributes.put("AbstractServiceImplementation", SKIP);
+		expectedProblemAttributes.put("AllocatingLocalInStaticContext", SKIP);
 		expectedProblemAttributes.put("AmbiguousConstructor", SKIP);
 		expectedProblemAttributes.put("AmbiguousConstructorInDefaultConstructor", SKIP);
 		expectedProblemAttributes.put("AmbiguousConstructorInImplicitConstructorCall", SKIP);