Bug 425102 QObject::connect content assist broken

The QObject::connect content assistant does not work when the receiver
of the function call is an implicit this.  E.g.,

class Q : public QObject { Q_OBJECT
    f()
    {
        this->connect( ... );   // works
        connect( ... );         // does not work
        QObject::connect( ... ) // does not work
    }
};

I've changed the Qt's ASTUtil.getReceiverType to navigate to the
ICPPClassType through the IScope's.  The previous implementation was
relying on the connect function call being an IASTField

I've also added a test case for this problem.

Change-Id: I96c29a9a452280068bda39a63414c50008bfad37
Signed-off-by: Andrew Eidsness <eclipse@jfront.com>
Reviewed-on: https://git.eclipse.org/r/20399
Tested-by: Hudson CI
Reviewed-by: Doug Schaefer <dschaefer@qnx.com>
IP-Clean: Doug Schaefer <dschaefer@qnx.com>

qt/org.eclipse.cdt.qt.core/META-INF/MANIFEST.MF

@@ -14,7 +14,7 @@ Require-Bundle: org.eclipse.core.runtime,
 Bundle-RequiredExecutionEnvironment: JavaSE-1.6
 Bundle-ActivationPolicy: lazy
 Bundle-Localization: plugin
-Export-Package: org.eclipse.cdt.internal.qt.core;x-friends:="org.eclipse.cdt.qt.ui",
+Export-Package: org.eclipse.cdt.internal.qt.core;x-friends:="org.eclipse.cdt.qt.ui,org.eclipse.cdt.qt.tests",
  org.eclipse.cdt.internal.qt.core.index;x-friends:="org.eclipse.cdt.qt.tests",
  org.eclipse.cdt.internal.qt.core.parser;x-friends:="org.eclipse.cdt.qt.ui",
  org.eclipse.cdt.qt.core,

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/ASTUtil.java

@@ -22,13 +22,14 @@ import org.eclipse.cdt.core.dom.ast.IASTName;
 import org.eclipse.cdt.core.dom.ast.IASTNode;
 import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
 import org.eclipse.cdt.core.dom.ast.IBinding;
+import org.eclipse.cdt.core.dom.ast.IScope;
 import org.eclipse.cdt.core.dom.ast.IType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTCompositeTypeSpecifier;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTExpression;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFieldReference;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTInitializerClause;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTVisibilityLabel;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPBinding;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassScope;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPMethod;
 import org.eclipse.cdt.core.model.ICProject;
@@ -36,6 +37,7 @@ import org.eclipse.cdt.core.model.ITranslationUnit;
 import org.eclipse.cdt.internal.core.dom.parser.ITypeContainer;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPEvaluation;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPInternalBinding;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPVisitor;
 import org.eclipse.cdt.qt.core.QtPlugin;
 import org.eclipse.cdt.qt.core.index.IQMethod;
 import org.eclipse.cdt.qt.core.index.IQObject;
@@ -144,21 +146,17 @@ public class ASTUtil {
 	}
 
 	public static ICPPClassType getReceiverType(IASTFunctionCallExpression fncall) {
+		// See the thread that starts at:
+		//     http://dev.eclipse.org/mhonarc/lists/cdt-dev/msg26972.html
+		try {
+			for(IScope scope = CPPVisitor.getContainingScope(fncall); scope != null; scope = scope.getParent())
+				if (scope instanceof ICPPClassScope)
+					return ((ICPPClassScope) scope).getClassType();
+		} catch (DOMException e) {
+			QtPlugin.log(e);
+		}
 
-		// NOTE: This cannot rely on the Evaluation because we're in a contest assist context.
+		return null;
-		//       At this point is likely that the full function call is not complete, so at least
-		//       some of the eval leads to a Problem.  We don't need the Eval anyhow, just lookup
-		//       the type of the receiver.
-
-		IASTExpression fnName = fncall.getFunctionNameExpression();
-		if (!(fnName instanceof ICPPASTFieldReference))
-			return null;
-
-		ICPPASTFieldReference fieldRef = (ICPPASTFieldReference) fnName;
-		ICPPASTExpression receiver = fieldRef.getFieldOwner();
-
-		IType recvType = getBaseType(receiver);
-		return recvType instanceof ICPPClassType ? (ICPPClassType) recvType : null;
 	}
 
 	/**

qt/org.eclipse.cdt.qt.tests/src/org/eclipse/cdt/qt/tests/ASTUtilTests.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2014 QNX Software Systems 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.eclipse.cdt.qt.tests;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.cdt.core.dom.ast.IASTFunctionCallExpression;
+import org.eclipse.cdt.core.dom.ast.IASTNode;
+import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassType;
+import org.eclipse.cdt.core.parser.ParserLanguage;
+import org.eclipse.cdt.core.parser.tests.ast2.AST2TestBase;
+import org.eclipse.cdt.internal.qt.core.ASTUtil;
+
+public class ASTUtilTests extends AST2TestBase {
+
+	// class T
+	// {
+	//     void callee() { }
+	//     void caller() { this->callee(); callee(); T::callee(); }
+	// };
+	// void T::callee()  { this->caller(); caller(); T::caller(); }
+	public void testGetReceiverType() throws Exception {
+		IASTTranslationUnit tu = parse();
+		assertNotNull(tu);
+
+		// Find the callee function call.
+		ArrayList<IASTFunctionCallExpression> fnCalls = new ArrayList<IASTFunctionCallExpression>();
+		collectChildren(fnCalls, tu, IASTFunctionCallExpression.class);
+		assertEquals(6, fnCalls.size());
+
+		assertNotNull(fnCalls.get(0));
+		assertNotNull(fnCalls.get(1));
+		assertNotNull(fnCalls.get(2));
+		assertNotNull(fnCalls.get(3));
+		assertNotNull(fnCalls.get(4));
+		assertNotNull(fnCalls.get(5));
+
+		ICPPClassType recvr0 = ASTUtil.getReceiverType(fnCalls.get(0));
+		ICPPClassType recvr1 = ASTUtil.getReceiverType(fnCalls.get(1));
+		ICPPClassType recvr2 = ASTUtil.getReceiverType(fnCalls.get(2));
+		ICPPClassType recvr3 = ASTUtil.getReceiverType(fnCalls.get(3));
+		ICPPClassType recvr4 = ASTUtil.getReceiverType(fnCalls.get(4));
+		ICPPClassType recvr5 = ASTUtil.getReceiverType(fnCalls.get(5));
+
+		assertNotNull(recvr0);
+		assertNotNull(recvr1);
+		assertNotNull(recvr2);
+		assertNotNull(recvr3);
+		assertNotNull(recvr4);
+		assertNotNull(recvr5);
+		assertSame(recvr0, recvr1);
+		assertSame(recvr1, recvr2);
+		assertSame(recvr3, recvr4);
+		assertSame(recvr4, recvr5);
+	}
+
+	private IASTTranslationUnit parse() throws Exception {
+		String[] contents = BaseQtTestCase.getContentsForTest(getClass(), 1);
+		return parse(contents[0], ParserLanguage.CPP);
+	}
+
+	private static <T> void collectChildren(List<T> list, IASTNode node, Class<T> cls) {
+		if (cls.isAssignableFrom(node.getClass()))
+			list.add(cls.cast(node));
+
+		for(IASTNode child : node.getChildren())
+			collectChildren(list, child, cls);
+	}
+}

qt/org.eclipse.cdt.qt.tests/src/org/eclipse/cdt/qt/tests/AllQtTests.java

@@ -15,6 +15,7 @@ public class AllQtTests extends TestSuite {
 	public static Test suite() throws Exception {
 		return
 			new TestSuite(
+				ASTUtilTests.class,
 				QMakeTests.class,
 				QGadgetTests.class,
 				QObjectTests.class,

qt/org.eclipse.cdt.qt.tests/src/org/eclipse/cdt/qt/tests/BaseQtTestCase.java

@@ -112,18 +112,26 @@ public class BaseQtTestCase extends BaseTestCase {
 		loadComment("junit-QObject.hh");
 	}
 
-	private String[] getContentsForTest(int blocks) throws Exception {
+	private static String[] getContentsForTest(Class<?> testCaseCls, int frames, int blocks) throws Exception {
-    	String callingMethod = Thread.currentThread().getStackTrace()[3].getMethodName();
+    	String callingMethod = Thread.currentThread().getStackTrace()[frames].getMethodName();
     	CharSequence[] help= TestSourceReader.getContentsForTest(
-    			QtTestPlugin.getDefault().getBundle(), "src", getClass(), callingMethod, blocks);
+    			QtTestPlugin.getDefault().getBundle(), "src", testCaseCls, callingMethod, blocks);
     	String[] result= new String[help.length];
     	int i= 0;
     	for (CharSequence buf : help) {
 			result[i++]= buf.toString();
 		}
     	return result;
+	}
+
+	private String[] getContentsForTest(int blocks) throws Exception {
+		return getContentsForTest(getClass(), 4, blocks);
     }
 
+	/*package*/ static String[] getContentsForTest(Class<?> testCaseCls, int blocks) throws Exception {
+		return getContentsForTest(testCaseCls, 4, blocks);
+	}
+
 	/**
 	 * The implementation of TestSourceReader (called from BaseTestCase) imposes some restrictions
 	 * on the caller of #loadComment.