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/*******************************************************************************
 * Copyright (c) 2000, 2024 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Stephan Herrmann - Contributions for
 *     							bug 349326 - [1.7] new warning for missing try-with-resources
 *								bug 359334 - Analysis for resource leak warnings does not consider exceptions as method exit points
 *								bug 358903 - Filter practically unimportant resource leak warnings
 *								bug 368546 - [compiler][resource] Avoid remaining false positives found when compiling the Eclipse SDK
 *								bug 370639 - [compiler][resource] restore the default for resource leak warnings
 *								bug 388996 - [compiler][resource] Incorrect 'potential resource leak'
 *								bug 379784 - [compiler] "Method can be static" is not getting reported
 *								bug 394768 - [compiler][resource] Incorrect resource leak warning when creating stream in conditional
 *								bug 404649 - [1.8][compiler] detect illegal reference to indirect or redundant super
 *								Bug 429958 - [1.8][null] evaluate new DefaultLocation attribute of @NonNullByDefault
 *								Bug 371614 - [compiler][resource] Wrong "resource leak" problem on return/throw inside while loop
 *								Bug 421035 - [resource] False alarm of resource leak warning when casting a closeable in its assignment
 *								Bug 444964 - [1.7+][resource] False resource leak warning (try-with-resources for ByteArrayOutputStream - return inside for loop)
 *								Bug 396575 - [compiler][resources] Incorrect Errors/Warnings check for potential resource leak when surrounding with try-catch
 *     Jesper S Moller  - Contributions for
 *								bug 378674 - "The method can be declared as static" is wrong
 *     Keigo Imai - Contribution for  bug 388903 - Cannot extend inner class as an anonymous class when it extends the outer class
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.lookup;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ast.*;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.codegen.CodeStream;
import org.eclipse.jdt.internal.compiler.flow.FlowContext;
import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.problem.ProblemReporter;

public class BlockScope extends Scope {

	// Local variable management
	public LocalVariableBinding[] locals;
	public int localIndex; // position for next variable
	public int startIndex;	// start position in this scope - for ordering scopes vs. variables
	public int offset; // for variable allocation throughout scopes
	public int maxOffset; // for variable allocation throughout scopes

	// finally scopes must be shifted behind respective try&catch scope(s) so as to avoid
	// collisions of secret variables (return address, save value).
	public BlockScope[] shiftScopes;

	public Scope[] subscopes = new Scope[1]; // need access from code assist
	public int subscopeCount = 0; // need access from code assist
	// record the current case statement being processed (for entire switch case block).
	public CaseStatement enclosingCase; // from 1.4 on, local types should not be accessed across switch case blocks (52221)

	public final static VariableBinding[] EmulationPathToImplicitThis = {};
	public final static VariableBinding[] NoEnclosingInstanceInConstructorCall = {};

	public final static VariableBinding[] NoEnclosingInstanceInStaticContext = {};

	// annotation support
	public boolean insideTypeAnnotation = false;
	public Statement blockStatement;
	public boolean resolvingGuardExpression = false;

    private boolean reparentLocals = false;

public BlockScope(BlockScope parent) {
	this(parent, true);
}

public BlockScope(BlockScope parent, boolean addToParentScope) {
	this(Scope.BLOCK_SCOPE, parent);
	this.locals = new LocalVariableBinding[5];
	if (addToParentScope) parent.addSubscope(this);
	this.startIndex = parent.localIndex;
}

public BlockScope(BlockScope parent, int variableCount) {
	this(Scope.BLOCK_SCOPE, parent);
	this.locals = new LocalVariableBinding[variableCount];
	parent.addSubscope(this);
	this.startIndex = parent.localIndex;
}

protected BlockScope(int kind, Scope parent) {
	super(kind, parent);
}

/* Create the class scope & binding for the anonymous type.
 */
public final void addAnonymousType(TypeDeclaration anonymousType, ReferenceBinding superBinding) {
	ClassScope anonymousClassScope = new ClassScope(this, anonymousType);
	anonymousClassScope.buildAnonymousTypeBinding(
		enclosingSourceType(),
		superBinding);

	/* Tag any enclosing lambdas as instance capturing. Strictly speaking they need not be, unless the local/anonymous type references enclosing instance state.
	   but the types themselves track enclosing types regardless of whether the state is accessed or not. This creates a mismatch in expectations in code generation
	   time, if we choose to make the lambda method static. To keep things simple and avoid a messy rollback, we force the lambda to be an instance method under
	   this situation. However if per source, the lambda occurs in a static context, we would generate a static synthetic method.
	*/
	MethodScope methodScope = methodScope();
	while (methodScope != null && methodScope.referenceContext instanceof LambdaExpression) {
		LambdaExpression lambda = (LambdaExpression) methodScope.referenceContext;
		if (!lambda.scope.isStatic && !lambda.scope.isConstructorCall) {
			if (!lambda.inPreConstructorContext)
				lambda.shouldCaptureInstance = true;
		}
		methodScope = methodScope.enclosingMethodScope();
	}
}

/* Create the class scope & binding for the local type.
 */
public final void addLocalType(TypeDeclaration localType) {
	ClassScope localTypeScope = new ClassScope(this, localType);
	addSubscope(localTypeScope);
	localTypeScope.buildLocalTypeBinding(enclosingSourceType());

	// See comment in addAnonymousType.
	MethodScope methodScope = methodScope();
	while (methodScope != null && methodScope.referenceContext instanceof LambdaExpression) {
		LambdaExpression lambda = (LambdaExpression) methodScope.referenceContext;
		if (!lambda.scope.isStatic && !lambda.scope.isConstructorCall) {
			lambda.shouldCaptureInstance = true;
		}
		methodScope = methodScope.enclosingMethodScope();
	}
}
/* Insert a local variable into a given scope, updating its position
 * and checking there are not too many locals or arguments allocated.
 */
public final void addLocalVariable(LocalVariableBinding binding) {
	if (this.reparentLocals) {
		BlockScope parentScope = (BlockScope) this.parent;
		parentScope.addLocalVariable(binding);
		this.startIndex = parentScope.localIndex;
		return;
	}
	checkAndSetModifiersForVariable(binding);
	// insert local in scope, skipping unnamed pattern variables.
	if (!binding.isPatternVariable() || !binding.declaration.isUnnamed(this)) {
		if (this.localIndex == this.locals.length)
			System.arraycopy(
				this.locals,
				0,
				(this.locals = new LocalVariableBinding[this.localIndex * 2]),
				0,
				this.localIndex);
		this.locals[this.localIndex++] = binding;
		binding.id = outerMostMethodScope().analysisIndex++; // share the outermost method scope analysisIndex
	}

	// update local variable binding
	binding.declaringScope = this;
}

public void addSubscope(Scope childScope) {
	if (this.subscopeCount == this.subscopes.length)
		System.arraycopy(
			this.subscopes,
			0,
			(this.subscopes = new Scope[this.subscopeCount * 2]),
			0,
			this.subscopeCount);
	this.subscopes[this.subscopeCount++] = childScope;
}

/**
 * Answer true if the receiver is suitable for assigning final blank fields.
 * in other words, it is inside an initializer, a constructor or a clinit
 */
public final boolean allowBlankFinalFieldAssignment(FieldBinding binding) {
	if (TypeBinding.notEquals(enclosingReceiverType(), binding.declaringClass))
		return false;

	MethodScope methodScope = methodScope();
	if (methodScope.isStatic != binding.isStatic())
		return false;
	if (methodScope.isLambdaScope())
		return false;
	return methodScope.isInsideInitializer() // inside initializer
			|| ((AbstractMethodDeclaration) methodScope.referenceContext).isInitializationMethod(); // inside constructor or clinit
}

String basicToString(int tab) {
	String newLine = "\n"; //$NON-NLS-1$
	for (int i = tab; --i >= 0;)
		newLine += "\t"; //$NON-NLS-1$

	String s = newLine + "--- Block Scope ---"; //$NON-NLS-1$
	newLine += "\t"; //$NON-NLS-1$
	s += newLine + "locals:"; //$NON-NLS-1$
	for (int i = 0; i < this.localIndex; i++)
		s += newLine + "\t" + this.locals[i].toString(); //$NON-NLS-1$
	s += newLine + "startIndex = " + this.startIndex; //$NON-NLS-1$
	return s;
}

private void checkAndSetModifiersForVariable(LocalVariableBinding varBinding) {
	int modifiers = varBinding.modifiers;
	if ((modifiers & ExtraCompilerModifiers.AccAlternateModifierProblem) != 0 && varBinding.declaration != null){
		problemReporter().duplicateModifierForVariable(varBinding.declaration, this instanceof MethodScope);
	}
	int realModifiers = modifiers & ExtraCompilerModifiers.AccJustFlag;

	int unexpectedModifiers = ~ClassFileConstants.AccFinal;
	if ((realModifiers & unexpectedModifiers) != 0 && varBinding.declaration != null){
		problemReporter().illegalModifierForVariable(varBinding.declaration, this instanceof MethodScope);
	}
	varBinding.modifiers = modifiers;
}

public void adjustLocalVariablePositions(int delta, boolean offsetAlreadyUpdated) {
	this.offset += offsetAlreadyUpdated ? 0 : delta;
	if (this.offset > this.maxOffset)
		this.maxOffset = this.offset;

	for (Scope subScope : this.subscopes) {
		if (subScope instanceof BlockScope) {
			((BlockScope) subScope).adjustCurrentAndSubScopeLocalVariablePositions(delta);
		}
	}

	Scope scope = this.parent;
	while (scope instanceof BlockScope) {
		BlockScope pBlock = (BlockScope) scope;
		int diff = this.maxOffset - pBlock.maxOffset;
		pBlock.maxOffset += diff > 0 ? diff : 0;
		if (scope instanceof MethodScope)
			break;
		scope = scope.parent;
	}
}
public void adjustCurrentAndSubScopeLocalVariablePositions(int delta) {
	this.offset += delta;
	if (this.offset > this.maxOffset)
		this.maxOffset = this.offset;

	for (LocalVariableBinding lvb : this.locals) {
		if (lvb != null && lvb.resolvedPosition != -1)
			lvb.resolvedPosition += delta;
	}
	for (Scope subScope : this.subscopes) {
		if (subScope instanceof BlockScope) {
			((BlockScope) subScope).adjustCurrentAndSubScopeLocalVariablePositions(delta);
		}
	}
}
/* Compute variable positions in scopes given an initial position offset
 * ignoring unused local variables.
 *
 * No argument is expected here (ilocal is the first non-argument local of the outermost scope)
 * Arguments are managed by the MethodScope method
 */
void computeLocalVariablePositions(int ilocal, int initOffset, CodeStream codeStream) {
	this.offset = initOffset;
	this.maxOffset = initOffset;

	// local variable init
	int maxLocals = this.localIndex;
	boolean hasMoreVariables = ilocal < maxLocals;

	// scope init
	int iscope = 0, maxScopes = this.subscopeCount;
	boolean hasMoreScopes = maxScopes > 0;

	// iterate scopes and variables in parallel
	while (hasMoreVariables || hasMoreScopes) {
		if (hasMoreScopes
			&& (!hasMoreVariables || (this.subscopes[iscope].startIndex() <= ilocal))) {
			// consider subscope first
			if (this.subscopes[iscope] instanceof BlockScope) {
				BlockScope subscope = (BlockScope) this.subscopes[iscope];
				int subOffset = subscope.shiftScopes == null ? this.offset : subscope.maxShiftedOffset();
				subscope.computeLocalVariablePositions(0, subOffset, codeStream);
				if (subscope.maxOffset > this.maxOffset)
					this.maxOffset = subscope.maxOffset;
			}
			hasMoreScopes = ++iscope < maxScopes;
		} else {

			// consider variable first
			LocalVariableBinding local = this.locals[ilocal]; // if no local at all, will be locals[ilocal]==null

			// check if variable is actually used, and may force it to be preserved
			boolean generateCurrentLocalVar = (local.useFlag > LocalVariableBinding.UNUSED && local.constant() == Constant.NotAConstant);

			// do not report fake used variable
			if (local.useFlag == LocalVariableBinding.UNUSED
				&& (local.declaration != null) // unused (and non secret) local
				&& ((local.declaration.bits & ASTNode.IsLocalDeclarationReachable) != 0) // declaration is reachable
				&& !local.declaration.isUnnamed(local.declaringScope)) {

				if (local.isCatchParameter()) {
					problemReporter().unusedExceptionParameter(local.declaration); // report unused catch arguments
				}
				else {
					problemReporter().unusedLocalVariable(local.declaration);
				}
			}

			// could be optimized out, but does need to preserve unread variables ?
			if (!generateCurrentLocalVar) {
				if ((local.declaration != null && compilerOptions().preserveAllLocalVariables) ||
						local.isPatternVariable()) { // too much voodoo around pattern codegen. Having warned, just treat them as used.
					generateCurrentLocalVar = true; // force it to be preserved in the generated code
					if (local.useFlag == LocalVariableBinding.UNUSED)
						local.useFlag = LocalVariableBinding.USED;
				}
			}

			// allocate variable
			if (generateCurrentLocalVar) {

				if (local.declaration != null) {
					codeStream.record(local); // record user-defined local variables for attribute generation
				}
				// assign variable position
				local.resolvedPosition = this.offset;

				if ((TypeBinding.equalsEquals(local.type, TypeBinding.LONG)) || (TypeBinding.equalsEquals(local.type, TypeBinding.DOUBLE))) {
					this.offset += 2;
				} else {
					this.offset++;
				}
				if (this.offset > 0xFFFF) { // no more than 65535 words of locals
					problemReporter().noMoreAvailableSpaceForLocal(
						local,
						local.declaration == null ? (ASTNode)methodScope().referenceContext : local.declaration);
				}
			} else {
				local.resolvedPosition = -1; // not generated
			}
			hasMoreVariables = ++ilocal < maxLocals;
		}
	}
	if (this.offset > this.maxOffset)
		this.maxOffset = this.offset;
}

/*
 *	Record the suitable binding denoting a synthetic field or constructor argument,
 * mapping to the actual outer local variable in the scope context.
 * Note that this may not need any effect, in case the outer local variable does not
 * need to be emulated and can directly be used as is (using its back pointer to its
 * declaring scope).
 */
public void emulateOuterAccess(LocalVariableBinding outerLocalVariable) {
	BlockScope outerVariableScope = outerLocalVariable.declaringScope;
	if (outerVariableScope == null)
		return; // no need to further emulate as already inserted (val$this$0)

	int depth = 0;
	Scope scope = this;
	while (outerVariableScope != scope) {
		switch(scope.kind) {
			case CLASS_SCOPE:
				depth++;
				break;
			case METHOD_SCOPE:
				if (scope.isLambdaScope()) {
					LambdaExpression lambdaExpression = (LambdaExpression) scope.referenceContext();
					lambdaExpression.addSyntheticArgument(outerLocalVariable);
				}
				break;
		}
		scope = scope.parent;
	}
	if (depth == 0)
		return;

	MethodScope currentMethodScope = methodScope();
	if (outerVariableScope.methodScope() != currentMethodScope) {
		NestedTypeBinding currentType = (NestedTypeBinding) enclosingSourceType();

		//do nothing for member types, pre emulation was performed already
		if (!currentType.isLocalType()) {
			return;
		}
		// must also add a synthetic field if we're not inside a constructor
		if (!currentMethodScope.isInsideInitializerOrConstructor()) {
			currentType.addSyntheticArgumentAndField(outerLocalVariable);
		} else {
			currentType.addSyntheticArgument(outerLocalVariable);
		}
	}
}

/* Note that it must never produce a direct access to the targetEnclosingType,
 * but instead a field sequence (this$2.this$1.this$0) so as to handle such a test case:
 *
 * class XX {
 *	void foo() {
 *		class A {
 *			class B {
 *				class C {
 *					boolean foo() {
 *						return (Object) A.this == (Object) B.this;
 *					}
 *				}
 *			}
 *		}
 *		new A().new B().new C();
 *	}
 * }
 * where we only want to deal with ONE enclosing instance for C (could not figure out an A for C)
 */
public final ReferenceBinding findLocalType(char[] name) {
	long compliance = compilerOptions().complianceLevel;
	for (int i = this.subscopeCount-1; i >= 0; i--) {
		if (this.subscopes[i] instanceof ClassScope) {
			LocalTypeBinding sourceType = (LocalTypeBinding)((ClassScope) this.subscopes[i]).referenceContext.binding;
			// from 1.4 on, local types should not be accessed across switch case blocks (52221)
			if (compliance >= ClassFileConstants.JDK1_4 && sourceType.enclosingCase != null) {
				if (!isInsideCase(sourceType.enclosingCase)) {
					continue;
				}
			}
			if (CharOperation.equals(sourceType.sourceName(), name))
				return sourceType;
		}
	}
	return null;
}

/**
 * Returns all declarations of most specific locals containing a given position in their source range.
 * This code does not recurse in nested types.
 * Returned array may have null values at trailing indexes.
 */
public LocalDeclaration[] findLocalVariableDeclarations(int position) {
	// local variable init
	int ilocal = 0, maxLocals = this.localIndex;
	boolean hasMoreVariables = maxLocals > 0;
	LocalDeclaration[] localDeclarations = null;
	int declPtr = 0;

	// scope init
	int iscope = 0, maxScopes = this.subscopeCount;
	boolean hasMoreScopes = maxScopes > 0;

	// iterate scopes and variables in parallel
	while (hasMoreVariables || hasMoreScopes) {
		if (hasMoreScopes
			&& (!hasMoreVariables || (this.subscopes[iscope].startIndex() <= ilocal))) {
			// consider subscope first
			Scope subscope = this.subscopes[iscope];
			if (subscope.kind == Scope.BLOCK_SCOPE) { // do not dive in nested types
				localDeclarations = ((BlockScope)subscope).findLocalVariableDeclarations(position);
				if (localDeclarations != null) {
					return localDeclarations;
				}
			}
			hasMoreScopes = ++iscope < maxScopes;
		} else {
			// consider variable first
			LocalVariableBinding local = this.locals[ilocal]; // if no local at all, will be locals[ilocal]==null
			if (local != null && (local.modifiers & ExtraCompilerModifiers.AccOutOfFlowScope) == 0) {
				LocalDeclaration localDecl = local.declaration;
				if (localDecl != null) {
					if (localDecl.declarationSourceStart <= position) {
						if (position <= localDecl.declarationSourceEnd) {
							if (localDeclarations == null) {
								localDeclarations = new LocalDeclaration[maxLocals];
							}
							localDeclarations[declPtr++] = localDecl;
						}
					} else {
						return localDeclarations;
					}
				}
			}
			hasMoreVariables = ++ilocal < maxLocals;
			if (!hasMoreVariables && localDeclarations != null) {
				return localDeclarations;
			}
		}
	}
	return null;
}
@Override
public LocalVariableBinding findVariable(char[] variableName, InvocationSite invocationSite) {
	int varLength = variableName.length;
	for (int i = this.localIndex-1; i >= 0; i--) { // lookup backward to reach latest additions first
		LocalVariableBinding local = this.locals[i];
		if ((local.modifiers & ExtraCompilerModifiers.AccOutOfFlowScope) != 0)
			continue;
		char[] localName;
		if ((localName = local.name).length == varLength && CharOperation.equals(localName, variableName))
			return local;
	}
	return null;
}

/* API
 * flag is a mask of the following values VARIABLE (= FIELD or LOCAL), TYPE.
 * Only bindings corresponding to the mask will be answered.
 *
 *	if the VARIABLE mask is set then
 *		If the first name provided is a field (or local) then the field (or local) is answered
 *		Otherwise, package names and type names are consumed until a field is found.
 *		In this case, the field is answered.
 *
 *	if the TYPE mask is set,
 *		package names and type names are consumed until the end of the input.
 *		Only if all of the input is consumed is the type answered
 *
 *	All other conditions are errors, and a problem binding is returned.
 *
 *	NOTE: If a problem binding is returned, senders should extract the compound name
 *	from the binding & not assume the problem applies to the entire compoundName.
 *
 *	The VARIABLE mask has precedence over the TYPE mask.
 *
 *	InvocationSite implements
 *		isSuperAccess(); this is used to determine if the discovered field is visible.
 *		setFieldIndex(int); this is used to record the number of names that were consumed.
 *
 *	For example, getBinding({"foo","y","q", VARIABLE, site) will answer
 *	the binding for the field or local named "foo" (or an error binding if none exists).
 *	In addition, setFieldIndex(1) will be sent to the invocation site.
 *	If a type named "foo" exists, it will not be detected (and an error binding will be answered)
 *
 *	IMPORTANT NOTE: This method is written under the assumption that compoundName is longer than length 1.
 */
public Binding getBinding(char[][] compoundName, int mask, InvocationSite invocationSite, boolean needResolve) {
	Binding binding = getBinding(compoundName[0], mask | Binding.TYPE | Binding.PACKAGE, invocationSite, needResolve);
	invocationSite.setFieldIndex(1);
	if (binding instanceof VariableBinding) return binding;
	CompilationUnitScope unitScope = compilationUnitScope();
	// in the problem case, we want to ensure we record the qualified dependency in case a type is added
	// and we do not know that its package was also added (can happen with CompilationParticipants)
	unitScope.recordQualifiedReference(compoundName);
	if (!binding.isValidBinding()) return binding;

	int length = compoundName.length;
	int currentIndex = 1;
	foundType : if (binding instanceof PackageBinding) {
		PackageBinding packageBinding = (PackageBinding) binding;
		while (currentIndex < length) {
			unitScope.recordReference(packageBinding.compoundName, compoundName[currentIndex]);
			binding = packageBinding.getTypeOrPackage(compoundName[currentIndex++], module(), currentIndex max) max = subMaxOffset;
			}
		}
	}
	return max;
}

/**
 * Returns true if the context requires to check initialization of final blank fields.
 * in other words, it is inside an initializer, a constructor or a clinit
 */
public final boolean needBlankFinalFieldInitializationCheck(FieldBinding binding) {
	boolean isStatic = binding.isStatic();
	ReferenceBinding fieldDeclaringClass = binding.declaringClass;
	// loop in enclosing context, until reaching the field declaring context
	MethodScope methodScope = namedMethodScope();
	while (methodScope != null) {
		if (methodScope.isStatic != isStatic)
			return false;
		if (!methodScope.isInsideInitializer() // inside initializer
				&& !((AbstractMethodDeclaration) methodScope.referenceContext).isInitializationMethod()) { // inside constructor or clinit
			return false; // found some non-initializer context
		}
		ReferenceBinding enclosingType = methodScope.enclosingReceiverType();
		if (TypeBinding.equalsEquals(enclosingType, fieldDeclaringClass)) {
			return true; // found the field context, no need to check any further
		}
		if (!enclosingType.erasure().isAnonymousType()) {
			return false; // only check inside anonymous type
		}
		methodScope = methodScope.enclosingMethodScope().namedMethodScope();
	}
	return false;
}

/* Answer the problem reporter to use for raising new problems.
 *
 * Note that as a side-effect, this updates the current reference context
 * (unit, type or method) in case the problem handler decides it is necessary
 * to abort.
 */
@Override
public ProblemReporter problemReporter() {
	return methodScope().problemReporter();
}

/*
 * Code responsible to request some more emulation work inside the invocation type, so as to supply
 * correct synthetic arguments to any allocation of the target type.
 */
public void propagateInnerEmulation(ReferenceBinding targetType, boolean isEnclosingInstanceSupplied) {
	// no need to propagate enclosing instances, they got eagerly allocated already.

	SyntheticArgumentBinding[] syntheticArguments;
	if ((syntheticArguments = targetType.syntheticOuterLocalVariables()) != null) {
		for (SyntheticArgumentBinding syntheticArg : syntheticArguments) {
			// need to filter out the one that could match a supplied enclosing instance
			if (!(isEnclosingInstanceSupplied
				&& (TypeBinding.equalsEquals(syntheticArg.type, targetType.enclosingType())))) {
				emulateOuterAccess(syntheticArg.actualOuterLocalVariable);
			}
		}
	}
}

/* Answer the reference type of this scope.
 *
 * It is the nearest enclosing type of this scope.
 */
public TypeDeclaration referenceType() {
	return methodScope().referenceType();
}

/*
 * Answer the index of this scope relatively to its parent.
 * For method scope, answers -1 (not a classScope relative position)
 */
public int scopeIndex() {
	if (this instanceof MethodScope) return -1;
	BlockScope parentScope = (BlockScope)this.parent;
	Scope[] parentSubscopes = parentScope.subscopes;
	for (int i = 0, max = parentScope.subscopeCount; i < max; i++) {
		if (parentSubscopes[i] == this) return i;
	}
	return -1;
}

// start position in this scope - for ordering scopes vs. variables
@Override
int startIndex() {
	return this.startIndex;
}

@Override
public String toString() {
	return toString(0);
}

public String toString(int tab) {
	String s = basicToString(tab);
	for (int i = 0; i < this.subscopeCount; i++)
		if (this.subscopes[i] instanceof BlockScope)
			s += ((BlockScope) this.subscopes[i]).toString(tab + 1) + "\n"; //$NON-NLS-1$
	return s;
}

private List trackingVariables; // can be null if no resources are tracked
/** Used only during analyseCode and only for checking if a resource was closed in a finallyBlock. */
public FlowInfo finallyInfo;

/**
 * Register a tracking variable and compute its id.
 */
public int registerTrackingVariable(FakedTrackingVariable fakedTrackingVariable) {
	if (this.trackingVariables == null)
		this.trackingVariables = new ArrayList<>(3);
	this.trackingVariables.add(fakedTrackingVariable);
	MethodScope outerMethodScope = outerMostMethodScope();
	return outerMethodScope.analysisIndex++;
}
/** When are no longer interested in this tracking variable - remove it. */
public void removeTrackingVar(FakedTrackingVariable trackingVariable) {
	if (trackingVariable.innerTracker != null) {
		trackingVariable.innerTracker.withdraw();
		trackingVariable.innerTracker = null;
	}
	if (this.trackingVariables != null)
		if (this.trackingVariables.remove(trackingVariable))
			return;
	if (this.parent instanceof BlockScope)
		((BlockScope)this.parent).removeTrackingVar(trackingVariable);
}
/** Unregister a wrapper resource without affecting its inner. */
public void pruneWrapperTrackingVar(FakedTrackingVariable trackingVariable) {
	this.trackingVariables.remove(trackingVariable);
}

public boolean hasResourceTrackers() {
	return this.trackingVariables != null && !this.trackingVariables.isEmpty();
}

/**
 * At the end of a block check the closing-status of all tracked closeables that are declared in this block.
 * Also invoked when entering unreachable code.
 */
public void checkUnclosedCloseables(FlowInfo flowInfo, FlowContext flowContext, ASTNode location, BlockScope locationScope) {
	if (!compilerOptions().analyseResourceLeaks) return;
	boolean exitAtEndOfMethod = location != null && locationScope == this && locationScope.isLastInMethod(null, location);
	if (this.trackingVariables == null
			|| (!(this instanceof MethodScope) && exitAtEndOfMethod))
	{
		// at a method return we also consider enclosing scopes
		if (location != null && this.parent instanceof BlockScope && !isLambdaScope())
			((BlockScope) this.parent).checkUnclosedCloseables(flowInfo, flowContext, location, locationScope);
		return;
	}
	if (location != null && flowInfo.reachMode() != 0) return;

	boolean useOwningAnnotations = this.compilerOptions().isAnnotationBasedResourceAnalysisEnabled;
	FakedTrackingVariable returnVar = (location instanceof ReturnStatement)
			? FakedTrackingVariable.getCloseTrackingVariable(((ReturnStatement)location).expression, flowInfo, flowContext, useOwningAnnotations)
			: null;

	// iterate variables according to the priorities defined in FakedTrackingVariable.IteratorForReporting.Stage
	Iterator iterator = new FakedTrackingVariable.IteratorForReporting(this.trackingVariables, this, location != null);
	while (iterator.hasNext()) {
		FakedTrackingVariable trackingVar = iterator.next();

		if (returnVar != null && trackingVar.isResourceBeingReturned(returnVar, useOwningAnnotations)) {
			if (useOwningAnnotations) {
				long methodTagBits = methodScope().referenceMethodBinding().tagBits;
				if ((methodTagBits & TagBits.AnnotationOwning) == 0) {
					// returning resource against unannotated return type
					LocalVariableBinding original = trackingVar.originalBinding;
					if (original != null && original.isParameter() && (original.tagBits & TagBits.AnnotationOwning) == 0) {
						// unannotated pass-through resource, remain quiet
						trackingVar.markAsShared();
					} else if ((methodTagBits & TagBits.AnnotationNotOwning) == 0) {
						// resource is "probably owned", should delegate to caller
						problemReporter().shouldMarkMethodAsOwning(location);
						trackingVar.withdraw();
					}
					if (!exitAtEndOfMethod)
						continue;
				} else {
					trackingVar.markAsShared();
				}
				// else proceed to precise analysis vis-a-vis @Owning below
			} else {
				continue; // silent assumption that caller will handle it
			}
		}

		if (location != null && trackingVar.hasDefinitelyNoResource(flowInfo)) {
			continue; // reporting against a specific location, there is no resource at this flow, don't complain
		}

		ASTNode locToBlame = location;
		if (!trackingVar.isShared() && !trackingVar.closeSeen() && locationScope != null && locationScope.isLastInMethod(null, location)) {
			locToBlame = null; // at end of method there's no point in specifically blaming the final return (unless other returns may have seen a close)
		}

		if (locToBlame != null && flowContext != null && flowContext.recordExitAgainstResource(this, flowInfo, trackingVar, location)) {
			continue; // handled by the flow context
		}

		if (!trackingVar.hasRecordedLocations() && trackingVar.isClosedInFinally()) {
			continue;
		}

		// compute the most specific null status for this resource,
		int status = trackingVar.findMostSpecificStatus(flowInfo, this, locationScope);

		if (status == FlowInfo.NULL) {
			if (trackingVar.isClosedInNestedMethod()) {
				status = FlowInfo.POTENTIALLY_NULL;
			} else {
				// definitely unclosed: highest priority
				reportResourceLeak(trackingVar, locToBlame, status, exitAtEndOfMethod);
				continue;
			}
		}
		if (locToBlame == null || exitAtEndOfMethod) { // at end of block and not definitely unclosed
			// look for problems at specific locations: medium priority
			if (trackingVar.reportRecordedErrors(this, status, flowInfo.reachMode() != FlowInfo.REACHABLE)) // ... report previously recorded errors
				continue;
		}
		if (status == FlowInfo.POTENTIALLY_NULL) {
			// potentially unclosed: lower priority
			reportResourceLeak(trackingVar, locToBlame, status, exitAtEndOfMethod);
		} else if (status == FlowInfo.NON_NULL) {
			// properly closed but not managed by t-w-r: lowest priority
			if (environment().globalOptions.complianceLevel >= ClassFileConstants.JDK1_7)
				trackingVar.reportExplicitClosing(problemReporter());
		}
	}
	if (location == null || exitAtEndOfMethod) {
		// when leaving this block dispose off all tracking variables:
		for (int i=0; i 0) {
		Statement lastStatement = blockStatements[blockStatements.length-1];
		if (lastStatement == location) {
			Scope current = this;
			Scope currentParent;
			// at each level in the parent chain:
			while (!(current instanceof MethodScope) && (currentParent = current.parent) instanceof BlockScope) {
				Scope lastSubScope = ((BlockScope) currentParent).findLastRelevantSubScope();
				// are we within that arm of the last relevant subScope?
				if (lastSubScope != null && lastSubScope != current) {
					return false;
				}
				current = currentParent;
			}
			return true;
		} else if (lastStatement instanceof Block aBlock) {
			return block != null && block.scope.isLastInMethod(aBlock, location);
		} else if (lastStatement instanceof TryStatement tryStatement) {
			// which block is last (try or finally)?
			if (tryStatement.finallyBlock == null || tryStatement.finallyBlock.statements == null) {
				return tryStatement.tryBlock.scope.isLastInMethod(tryStatement.tryBlock, location);
			} else {
				return tryStatement.finallyBlock.scope.isLastInMethod(tryStatement.finallyBlock, location);
			}
		}
		// loops are trickier: would need to inspect every potential exit.
	}
	return false;
}

protected Scope findLastRelevantSubScope() {
	int lastIdx = this.subscopeCount-1;
	Scope lastSubScope = null;
	while (lastIdx >= 0) {
		lastSubScope = this.subscopes[lastIdx];
		if (lastSubScope instanceof BlockScope)
			break;
		lastIdx--;
	}
	return lastSubScope;
}

private void reportResourceLeak(FakedTrackingVariable trackingVar, ASTNode location, int nullStatus, boolean reportImmediately) {
	if (location != null && !reportImmediately && trackingVar.originalBinding != null) {
		trackingVar.recordErrorLocation(location, nullStatus);
	} else {
		trackingVar.reportError(problemReporter(), location, nullStatus);
	}
}

/**
 * If one branch of an if-else closes any AutoCloseable resource, and if the same
 * resource is known to be null on the other branch mark it as closed, too,
 * so that merging both branches indicates that the resource is always closed.
 * Example:
 *	FileReader fr1 = null;
 *	try {\n" +
 *      fr1 = new FileReader(someFile);" +
 *		fr1.read(buf);\n" +
 *	} finally {\n" +
 *		if (fr1 != null)\n" +
 *           try {\n" +
 *               fr1.close();\n" +
 *           } catch (IOException e) {
 *              // do nothing
 *           }
 *      // after this if statement fr1 is definitely not leaked
 *	}
 */
public void correlateTrackingVarsIfElse(FlowInfo thenFlowInfo, FlowInfo elseFlowInfo) {
	if (this.trackingVariables != null) {
		int trackVarCount = this.trackingVariables.size();
		for (int i=0; i always closed
			}
			else if (   elseFlowInfo.isDefinitelyNonNull(trackingVar.binding)		// closed in else branch
					 && thenFlowInfo.isDefinitelyNull(trackingVar.originalBinding))	// null in then branch
			{
				thenFlowInfo.markAsDefinitelyNonNull(trackingVar.binding);			// -> always closed
			}
			else {
				if (thenFlowInfo == FlowInfo.DEAD_END || elseFlowInfo == FlowInfo.DEAD_END)
					continue; // short cut

				for (int j=i+1; j 0 && right != null && right.length > 0) {
		for (LocalVariableBinding leftVar : left) {
			for (LocalVariableBinding rightVar : right) {
				if (CharOperation.equals(leftVar.name, rightVar.name)) {
					problemReporter().illegalRedeclarationOfPatternVar(rightVar, rightVar.declaration);
				}
			}
		}
	}
}

@Override
public boolean resolvingGuardExpression() {
	return this.resolvingGuardExpression;
}

public void include(LocalVariableBinding[] bindings) {
	// `this` is assumed to be populated with bindings.
	if (bindings != null) {
		for (LocalVariableBinding binding : bindings) {
			binding.modifiers &= ~ExtraCompilerModifiers.AccOutOfFlowScope;
		}
	}
}

public void exclude(LocalVariableBinding[] bindings) {
	// `this` is assumed to be populated with bindings.
	if (bindings != null) {
		for (LocalVariableBinding binding : bindings) {
			binding.modifiers |= ExtraCompilerModifiers.AccOutOfFlowScope;
		}
	}
}

}




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