feature: add filter helpers (LocalVariableReferenceFunction, LocalVar…

…iableScopeFunction) (#1144)

* feature: add LocalVariableScopeFunction, LocalVariableReferenceFunction

* test LocalVariableReferenceFunction

* fix comment

src/main/java/spoon/reflect/visitor/filter/LocalVariableReferenceFunction.java

@@ -0,0 +1,49 @@
+/**
+ * Copyright (C) 2006-2017 INRIA and contributors
+ * Spoon - http://spoon.gforge.inria.fr/
+ *
+ * This software is governed by the CeCILL-C License under French law and
+ * abiding by the rules of distribution of free software. You can use, modify
+ * and/or redistribute the software under the terms of the CeCILL-C license as
+ * circulated by CEA, CNRS and INRIA at http://www.cecill.info.
+ *
+ * This program 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 CeCILL-C License for more details.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL-C license and that you accept its terms.
+ */
+package spoon.reflect.visitor.filter;
+
+import spoon.reflect.code.CtLocalVariable;
+import spoon.reflect.reference.CtLocalVariableReference;
+import spoon.reflect.visitor.chain.CtConsumableFunction;
+import spoon.reflect.visitor.chain.CtConsumer;
+
+/**
+ * This Query expects a {@link CtLocalVariable} as input
+ * and returns all {@link CtLocalVariableReference}s, which refers this input.
+ * <br>
+ * Usage:<br>
+ * <pre> {@code
+ * CtLocalVariable var = ...;
+ * var
+ *   .map(new LocalVariableReferenceFunction())
+ *   .forEach((CtLocalVariableReference ref)->...process references...);
+ * }
+ * </pre>
+ */
+public class LocalVariableReferenceFunction implements CtConsumableFunction<CtLocalVariable<?>> {
+
+	public LocalVariableReferenceFunction() {
+	}
+
+	@Override
+	public void apply(CtLocalVariable<?> localVariable, CtConsumer<Object> outputConsumer) {
+		localVariable
+			.map(new LocalVariableScopeFunction())
+			.select(new DirectReferenceFilter<CtLocalVariableReference<?>>(localVariable.getReference()))
+			.forEach(outputConsumer);
+	}
+}

src/main/java/spoon/reflect/visitor/filter/LocalVariableScopeFunction.java

@@ -0,0 +1,71 @@
+/**
+ * Copyright (C) 2006-2017 INRIA and contributors
+ * Spoon - http://spoon.gforge.inria.fr/
+ *
+ * This software is governed by the CeCILL-C License under French law and
+ * abiding by the rules of distribution of free software. You can use, modify
+ * and/or redistribute the software under the terms of the CeCILL-C license as
+ * circulated by CEA, CNRS and INRIA at http://www.cecill.info.
+ *
+ * This program 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 CeCILL-C License for more details.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL-C license and that you accept its terms.
+ */
+package spoon.reflect.visitor.filter;
+
+import java.util.List;
+
+import spoon.SpoonException;
+import spoon.reflect.code.CtLocalVariable;
+import spoon.reflect.code.CtStatement;
+import spoon.reflect.code.CtStatementList;
+import spoon.reflect.visitor.chain.CtConsumableFunction;
+import spoon.reflect.visitor.chain.CtConsumer;
+import spoon.reflect.visitor.chain.CtQuery;
+
+/**
+ * This Query expects a {@link CtLocalVariable} as input
+ * and returns all CtElements,
+ * which are in visibility scope of that local variable.
+ * In other words, it returns all elements,
+ * which might be reference to that local variable.
+ * <br>
+ * It can be used to search for variable declarations or
+ * variable references which might be in name conflict with input local variable.
+ * <br>
+ * Usage:<br>
+ * <pre> {@code
+ * CtLocalVariable var = ...;
+ * var.map(new LocalVariableScopeFunction()).forEach(...process result...);
+ * }
+ * </pre>
+ */
+public class LocalVariableScopeFunction implements CtConsumableFunction<CtLocalVariable<?>> {
+
+	public LocalVariableScopeFunction() {
+	}
+
+	@Override
+	public void apply(CtLocalVariable<?> localVariable, CtConsumer<Object> outputConsumer) {
+		CtStatementList statements = localVariable.getParent(CtStatementList.class);
+		if (statements == null) {
+			//cannot search for variable references of variable which has no parent statement list/block
+			return;
+		}
+		//create query which will be evaluated on each statement after local variable declaration
+		CtQuery query = localVariable.getFactory().createQuery().filterChildren(null);
+		List<CtStatement> stats = statements.getStatements();
+		//search for variable declaration in statements of current block
+		int idxOfVar = stats.indexOf(localVariable);
+		if (idxOfVar < 0) {
+			throw new SpoonException("Cannot found index of local variable declaration " + localVariable + " in statement list " + statements);
+		}
+		//scan only all elements AFTER this variable declaration
+		for (int i = idxOfVar + 1; i < stats.size(); i++) {
+			query.setInput(stats.get(i)).forEach(outputConsumer);
+		}
+	}
+}

src/test/java/spoon/test/query_function/QueryTest.java

@@ -9,6 +9,7 @@
 import spoon.reflect.code.CtCatchVariable;
 import spoon.reflect.code.CtExpression;
 import spoon.reflect.code.CtLiteral;
+import spoon.reflect.code.CtLocalVariable;
 import spoon.reflect.cu.SourcePosition;
 import spoon.reflect.cu.position.NoSourcePosition;
 import spoon.reflect.declaration.CtClass;
@@ -23,6 +24,7 @@
 import spoon.reflect.reference.CtVariableReference;
 import spoon.reflect.visitor.chain.CtConsumableFunction;
 import spoon.reflect.visitor.filter.CatchVariableReferenceFunction;
+import spoon.reflect.visitor.filter.LocalVariableReferenceFunction;
 import spoon.reflect.visitor.filter.ParameterReferenceFunction;
 import spoon.test.query_function.testclasses.packageA.ClassA;
 
@@ -96,7 +98,7 @@ class Context {
 		assertEquals(countOfModelClasses, context.classCount);
 	}
 
-  @Test
+	@Test
 	public void testParameterReferenceFunction() throws Exception {
 		//visits all the CtParameter elements whose name is "field" and search for all their references
 		//The test detects whether found references are correct by these two checks:
@@ -127,7 +129,23 @@ public void testCatchVariableReferenceFunction() throws Exception {
 			return false;
 		}).list();
 	}
-
+
+	@Test
+	public void testLocalVariableReferenceFunction() throws Exception {
+		//visits all the CtLocalVariable elements whose name is "field" and search for all their references
+		//The test detects whether found references are correct by these two checks:
+		//1) the each found reference is on the left side of binary operator and on the right side there is unique reference identification number. Like: (field == 7)
+		//2) the model is searched for all variable references which has same identification number and counts them
+		//Then it checks that counted number of references and found number of references is same 
+		factory.Package().getRootPackage().filterChildren((CtLocalVariable<?> var)->{
+			if(var.getSimpleName().equals("field")) {
+				int value = getLiteralValue(var);
+				checkVariableAccess(var, value, new LocalVariableReferenceFunction());
+			}
+			return false;
+		}).list();
+	}	
+
 	private void checkVariableAccess(CtVariable<?> var, int value, CtConsumableFunction<?> query) {
 		class Context {
 			int classCount = 0;