Bug 419301 - Remove stray friend functions from lookup results

Change-Id: I69f79de6f38226aeceb0dfecb22ae43193c8c696
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>
Reviewed-on: https://git.eclipse.org/r/19890
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
IP-Clean: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java

@@ -8216,4 +8216,21 @@ public class AST2TemplateTests extends AST2TestBase {
 		BindingAssertionHelper helper = getAssertionHelper();
 		helper.assertNonProblem("waldo<T>", ICPPDeferredFunction.class);
 	}
+	
+	//	template <typename>
+	//	struct C {
+	//	    friend bool operator==(C, C);
+	//	    friend bool operator!=(C, C);
+	//	};
+	//
+	//	template <typename U>
+	//	void waldo(U, U);
+	//
+	//	void test() {
+	//	  C<int> x;
+	//	  waldo(x, x);
+	//	}
+	public void testStrayFriends_419301() throws Exception {
+		parseAndCheckBindings();
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/util/ArrayUtil.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2004, 2009 IBM Corporation and others.
+ * Copyright (c) 2004, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -11,6 +11,7 @@
  *     Andrew Ferguson (Symbian)
  *     Mike Kucera (IBM)
  *     Sergey Prigogin (Google)
+ *     Nathan Ridge
  *******************************************************************************/
 package org.eclipse.cdt.core.parser.util;
 
@@ -741,4 +742,29 @@ public abstract class ArrayUtil {
         array[idx] = val;
         return array;
     }
+    
+    /**
+     * Filter the elements of an array down to just the ones
+     * that match the given predicate.
+	 * @since 5.6
+	 */
+	public static <T> T[] filter(T[] array, IUnaryPredicate<T> predicate) {
+		T[] result = array;
+		int resultIndex = 0;
+		for (int i = 0; i < array.length; ++i) {
+			if (predicate.apply(array[i])) {
+				if (result != array) {
+					result[resultIndex] = array[i];
+				}
+				++resultIndex;
+			} else {
+				if (result == array) {
+					// There will be at most array.length - 1 filtered elements. 
+					result = Arrays.copyOf(array, array.length - 1);
+					Arrays.fill(result, i, result.length, null);
+				}
+			}
+		}
+		return resultIndex == result.length ? result : Arrays.copyOf(result, resultIndex);
+    }
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/util/CollectionUtils.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2012 IBM Corporation and others.
+ * Copyright (c) 2006, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -8,6 +8,7 @@
  * Contributors:
  *     Mike Kucera (IBM Corporation) - initial API and implementation
  *     Sergey Prigogin (Google)
+ *     Nathan Ridge
  *******************************************************************************/
 package org.eclipse.cdt.core.parser.util;
 
@@ -151,4 +152,19 @@ public final class CollectionUtils {
 		}
 		return result;
 	}
+	
+    /**
+     * Filter the elements of a collection down to just the ones
+     * that match the given predicate.
+	 * @since 5.6
+	 */
+	public static <T> Collection<T> filter(Collection<T> collection, IUnaryPredicate<T> predicate) {
+		if (collection.isEmpty())
+			return collection;
+		Collection<T> result = new ArrayList<T>();
+		for (T t : collection)
+			if (predicate.apply(t))
+				result.add(t);
+		return result;
+    }
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/util/IUnaryPredicate.java

@@ -0,0 +1,20 @@
+/*******************************************************************************
+ * Copyright (c) 2013 Nathan Ridge.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * 	  Nathan Ridge - initial API
+ *******************************************************************************/
+package org.eclipse.cdt.core.parser.util;
+
+/**
+ * A generic unary predicate interface.
+ * Useful for operations that use unary predicates, like filtering an array.
+ * @since 5.6
+ */
+public interface IUnaryPredicate<T> {
+	boolean apply(T argument);
+}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java

@@ -180,7 +180,9 @@ import org.eclipse.cdt.core.index.IIndexName;
 import org.eclipse.cdt.core.parser.util.ArrayUtil;
 import org.eclipse.cdt.core.parser.util.CharArrayObjectMap;
 import org.eclipse.cdt.core.parser.util.CharArrayUtils;
+import org.eclipse.cdt.core.parser.util.CollectionUtils;
 import org.eclipse.cdt.core.parser.util.DebugUtil;
+import org.eclipse.cdt.core.parser.util.IUnaryPredicate;
 import org.eclipse.cdt.core.parser.util.ObjectSet;
 import org.eclipse.cdt.internal.core.dom.parser.ASTAmbiguousNode;
 import org.eclipse.cdt.internal.core.dom.parser.ASTInternal;
@@ -597,10 +599,26 @@ public class CPPSemantics {
 				lookup(data, scope);
 			}
 		}
-		mergeResults(data, friendFns.toArray(), false);
+		Object[] matchingFriendFns = CollectionUtils.filter(
+				friendFns, 
+				new NameMatcherPredicate(data.getLookupKey())).toArray();
+		mergeResults(data, matchingFriendFns, false);
 		data.qualified = originalQualified;
 	}
 	
+	private static class NameMatcherPredicate implements IUnaryPredicate<ICPPFunction> {
+		private char[] fKey;
+		
+		public NameMatcherPredicate(char[] key) {
+			fKey = key;
+		}
+		
+		@Override
+		public boolean apply(ICPPFunction argument) {
+			return Arrays.equals(argument.getNameCharArray(), fKey);
+		}
+	}
+	
 	static IBinding checkDeclSpecifier(IBinding binding, IASTName name, IASTNode decl) {
 		// Check for empty declaration specifiers.
 		if (!isCtorOrConversionOperator(binding)) {
@@ -1262,29 +1280,17 @@ public class CPPSemantics {
 		}
 
 		if (data.ignoreRecursionResolvingBindings()) {
-			bindings = filterOutRecursionResovingBindings(bindings);
+			bindings = ArrayUtil.filter(bindings, new RecursionResolvingBindingFilter());
 		}
 
 		return expandUsingDeclarationsAndRemoveObjects(bindings, data);
 	}
 
-	private static IBinding[] filterOutRecursionResovingBindings(IBinding[] bindings) {
-		IBinding[] result = bindings;
-		int resultIndex = 0;
-		for (int i = 0; i < bindings.length; ++i) {
-			if (bindings[i] instanceof IRecursionResolvingBinding) {
-				if (result == bindings) {
-					result = new IBinding[bindings.length - 1];
-					System.arraycopy(bindings, 0, result, 0, i);
+	private static class RecursionResolvingBindingFilter implements IUnaryPredicate<IBinding> {
+		@Override
+		public boolean apply(IBinding argument) {
+			return !(argument instanceof IRecursionResolvingBinding);
 		}
-			} else {
-				if (result != bindings) {
-					result[resultIndex] = bindings[i];
-				}
-				++resultIndex;
-			}
-		}
-		return ArrayUtil.trim(result);
 	}
 	
 	private static IBinding[] expandUsingDeclarationsAndRemoveObjects(final IBinding[] bindings,