Bug 422841: Add Q_CLASSINFO to the QtIndex

Qt allows string-based key/value pairs to be inserted into QObject class
definitions.  E.g.,

    class Q : public QObject
    {
    Q_OBJECT
    Q_CLASSINFO( "key1", "value1" )
    };

The class info is accessible in the meta-object system.  See:

    http://qt-project.org/doc/qt-4.8/qmetaclassinfo.html

For more information.

This patch adds the API to access these key/value pairs from the
QtIndex.  The values are stored in a single block in the PDOM record for
the QObject.

The API returns the value for a given key if it is found in the receiver
QObject or any of its base classes.  The API returns the first such
value that is found.

This patch also adds a test case for this functionality.

Change-Id: Ie3f821a0c5f6f1347a0c0c6dafa184510ae26c29
Signed-off-by: Andrew Eidsness <eclipse@jfront.com>
Reviewed-on: https://git.eclipse.org/r/19154
Tested-by: Hudson CI
Reviewed-by: Doug Schaefer <dschaefer@qnx.com>
IP-Clean: Doug Schaefer <dschaefer@qnx.com>
Tested-by: Doug Schaefer <dschaefer@qnx.com>

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/core/index/IQObject.java

@@ -38,6 +38,12 @@ public interface IQObject extends IQElement {
 	 */
 	public List<IQObject> getBases();
 
+	/**
+	 * Examines the Q_CLASSINFO expansions to return the value associated with the given
+	 * key.  Returns null if there isn't a Q_CLASSINFO for the given key.
+	 */
+	public String getClassInfo(String key);
+
 	/**
 	 * Returns an unsorted collection of all Q_ENUMS macro expansions within this QObject's class
 	 * declaration.

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/internal/core/index/QObject.java

@@ -10,6 +10,7 @@ package org.eclipse.cdt.qt.internal.core.index;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Map;
 
 import org.eclipse.cdt.core.dom.ast.IBinding;
 import org.eclipse.cdt.core.dom.ast.IField;
@@ -25,6 +26,7 @@ public class QObject implements IQObject {
 	private final QtPDOMQObject pdomQObject;
 	private final List<IQObject> bases;
 	private final List<IQEnum> enums;
+	private final Map<String, String> classInfos;
 
 	public QObject(QtIndexImpl qtIndex, CDTIndex cdtIndex, QtPDOMQObject pdomQObject) throws CoreException {
 		this.name = pdomQObject.getName();
@@ -34,6 +36,8 @@ public class QObject implements IQObject {
 		for(QtPDOMQObject base : pdomQObject.findBases())
 			this.bases.add(new QObject(qtIndex, cdtIndex, base));
 
+		this.classInfos = pdomQObject.getClassInfos();
+
 		this.enums = new ArrayList<IQEnum>();
 		for(IField field : pdomQObject.getFields())
 			if (field instanceof QtPDOMQEnum) {
@@ -57,6 +61,21 @@ public class QObject implements IQObject {
 		return bases;
 	}
 
+	@Override
+	public String getClassInfo(String key) {
+		String value = classInfos.get(key);
+		if (value != null)
+			return value;
+
+		for(IQObject base : bases) {
+			value = base.getClassInfo(key);
+			if (value != null)
+				return value;
+		}
+
+		return null;
+	}
+
 	@Override
 	public Collection<IQEnum> getEnums() {
 		return enums;

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/internal/core/pdom/QObjectName.java

@@ -7,6 +7,9 @@
  */
 package org.eclipse.cdt.qt.internal.core.pdom;
 
+import java.util.LinkedHashMap;
+import java.util.Map;
+
 import org.eclipse.cdt.core.dom.ILinkage;
 import org.eclipse.cdt.core.dom.ast.ASTNodeProperty;
 import org.eclipse.cdt.core.dom.ast.ASTVisitor;
@@ -25,6 +28,7 @@ import org.eclipse.cdt.internal.core.dom.Linkage;
 public class QObjectName extends ASTDelegatedName {
 
 	private final ICPPASTCompositeTypeSpecifier spec;
+	private final Map<String, String> classInfos = new LinkedHashMap<String, String>();
 
 	private IASTNode parent;
 	private ASTNodeProperty propertyInParent;
@@ -36,6 +40,14 @@ public class QObjectName extends ASTDelegatedName {
 		this.propertyInParent = delegate.getPropertyInParent();
 	}
 
+	public Map<String, String> getClassInfos() {
+		return classInfos;
+	}
+
+	public String addClassInfo(String key, String value) {
+		return classInfos.put(key, value);
+	}
+
 	@Override
 	protected IBinding createBinding() {
 		return new QtBinding(QtPDOMNodeType.QObject, this, spec.getName());

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/internal/core/pdom/QtASTVisitor.java

@@ -41,6 +41,16 @@ public class QtASTVisitor extends ASTVisitor {
 
 	private static final Pattern declareFlagsRegex = Pattern.compile("^Q_DECLARE_FLAGS\\s*\\(\\s*([^\\s]+),\\s*([^\\s]+)\\s*\\)$");
 
+	/**
+	 * A regular expression for scanning the Q_CLASSINFO expansion and extracting the
+	 * expansion parameter key and value.  It provides the following capture groups:
+	 * <br>1 - the key
+	 * <br>2 - the value
+	 * <p>
+	 * The key must not have embedded quotes.
+	 */
+	private static final Pattern classInfoRegex = Pattern.compile("^Q_CLASSINFO\\s*\\(\\s*\"([^\"]+)\"\\s*,\\s*\"(.*)\"\\s*\\)$");
+
 	public QtASTVisitor(IIndexSymbols symbols, LocationMap locationMap) {
 		shouldVisitDeclSpecifiers = true;
 
@@ -141,6 +151,13 @@ public class QtASTVisitor extends ASTVisitor {
 					String enumName = m.group(2);
 					flagAliases.put(flagName, enumName);
 				}
+			} else if(QtKeywords.Q_CLASSINFO.equals(macroName)) {
+				Matcher m = classInfoRegex.matcher(expansion.getRawSignature());
+				if (m.matches()) {
+					String key = m.group(1);
+					String value = m.group(2);
+					qobjName.addClassInfo(key, value);
+				}
 			}
 		}
 

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/internal/core/pdom/QtPDOMNodeType.java

@@ -26,7 +26,7 @@ public enum QtPDOMNodeType {
 	 * <p>
 	 * The version is needed because ordinals for these enumerators are written to the file.
 	 */
-	public static final int VERSION = 1;
+	public static final int VERSION = 2;
 
 	public static QtPDOMNodeType forType(int version, int type) {
 		// Nothing has been deleted or replaced yet, so the version is ignored.

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/internal/core/pdom/QtPDOMQObject.java

@@ -9,8 +9,11 @@ package org.eclipse.cdt.qt.internal.core.pdom;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 
+import org.eclipse.cdt.core.dom.ast.IASTName;
 import org.eclipse.cdt.core.dom.ast.IBinding;
 import org.eclipse.cdt.core.dom.ast.ICompositeType;
 import org.eclipse.cdt.core.dom.ast.IField;
@@ -18,6 +21,8 @@ import org.eclipse.cdt.core.dom.ast.IScope;
 import org.eclipse.cdt.core.dom.ast.IType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPBase;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassType;
+import org.eclipse.cdt.internal.core.pdom.db.Database;
+import org.eclipse.cdt.internal.core.pdom.db.IString;
 import org.eclipse.cdt.internal.core.pdom.db.PDOMNodeLinkedList;
 import org.eclipse.cdt.internal.core.pdom.dom.IPDOMBinding;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMNode;
@@ -37,6 +42,7 @@ public class QtPDOMQObject extends QtPDOMBinding implements ICompositeType {
 	private static int offsetInitializer = QtPDOMBinding.Field.Last.offset;
 	protected static enum Field {
 		Children(4 /* From PDOMNodeLinkedList.RECORD_SIZE, which is protected */),
+		ClassInfos(Database.PTR_SIZE),
 		Last(0);
 
 		private final int offset;
@@ -61,6 +67,76 @@ public class QtPDOMQObject extends QtPDOMBinding implements ICompositeType {
 	public QtPDOMQObject(QtPDOMLinkage linkage, QtBinding binding) throws CoreException {
 		super(linkage, null, binding);
 		children = new PDOMNodeLinkedList(linkage, Field.Children.getRecord(record));
+
+		IASTName qtName = binding.getQtName();
+		if (qtName instanceof QObjectName)
+			setClassInfos(((QObjectName) qtName).getClassInfos());
+	}
+
+	public void setClassInfos(Map<String, String> classInfos) throws CoreException {
+
+		// ClassInfo was not supported before version 2.
+		if (getQtLinkage().getVersion() < 2)
+			return;
+
+		// Delete all entries that are currently in the list.
+		long block = getDB().getRecPtr(Field.ClassInfos.getRecord(record));
+		if (block != 0) {
+			int numEntries = getDB().getInt(block);
+			for(long b = block + Database.INT_SIZE, end = block + (numEntries * 2 * Database.PTR_SIZE); b < end; b += Database.PTR_SIZE)
+				getDB().getString(b).delete();
+			getDB().free(block);
+		}
+
+		// Clear the pointer if the incoming map is empty.
+		if (classInfos.isEmpty()) {
+			getDB().putRecPtr(Field.ClassInfos.getRecord(record), 0);
+			return;
+		}
+
+		// Otherwise create a block large enough to hold the incoming list and then populate it.
+		block = getDB().malloc(Database.INT_SIZE + (classInfos.size() * 2 * Database.PTR_SIZE));
+		getDB().putInt(block, classInfos.size());
+
+		long b = block + Database.INT_SIZE;
+		for(Map.Entry<String, String> classInfo : classInfos.entrySet()) {
+			IString key = getDB().newString(classInfo.getKey());
+			IString val = getDB().newString(classInfo.getValue());
+
+			getDB().putRecPtr(b, key.getRecord()); b += Database.PTR_SIZE;
+			getDB().putRecPtr(b, val.getRecord()); b += Database.PTR_SIZE;
+		}
+
+		// Put the new block into the PDOM.
+		getDB().putRecPtr(Field.ClassInfos.getRecord(record), block);
+	}
+
+	public Map<String, String> getClassInfos() throws CoreException {
+		Map<String, String> classInfos = new LinkedHashMap<String, String>();
+
+		// ClassInfo was not supported before version 2.
+		if (getQtLinkage().getVersion() < 2)
+			return classInfos;
+
+		long block = getDB().getRecPtr(Field.ClassInfos.getRecord(record));
+		if (block != 0) {
+			int numEntries = getDB().getInt(block);
+			block += Database.INT_SIZE;
+
+			for(long end = block + (numEntries * 2 * Database.PTR_SIZE); block < end; /* in loop body */) {
+				long rec = getDB().getRecPtr(block);
+				IString key = getDB().getString(rec);
+				block += Database.PTR_SIZE;
+
+				rec = getDB().getRecPtr(block);
+				IString val = getDB().getString(rec);
+				block += Database.PTR_SIZE;
+
+				classInfos.put(key.getString(), val.getString());
+			}
+		}
+
+		return classInfos;
 	}
 
 	@Override

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

@@ -48,6 +48,41 @@ public class QObjectTests extends BaseQtTestCase {
 		assertNull(qobj_D2);
 	}
 
+    // #include "junit-QObject.hh"
+    // class B : public QObject
+    // {
+    // Q_OBJECT
+    // Q_CLASSINFO( "key1", "value1" )
+    // Q_CLASSINFO( "key2", "value\"2" )
+    // public:
+    //     bool isAllowed() const { return false; }
+    // };
+    // class D : public B
+    // {
+    // Q_OBJECT
+    // Q_CLASSINFO( "key2", "overridden value" )
+    // public:
+    //     bool isAllowed() const { return false; }
+    // };
+	public void testClassInfos() throws Exception {
+		loadComment("classinfos.hh");
+
+		QtIndex qtIndex = QtIndex.getIndex(fProject);
+		assertNotNull(qtIndex);
+
+		IQObject qobj_b = qtIndex.findQObject(new String[]{ "B" });
+		if (!isIndexOk("B", qobj_b))
+			return;
+		assertNotNull(qobj_b);
+		assertEquals("value1", qobj_b.getClassInfo("key1"));
+		assertEquals("value\\\"2", qobj_b.getClassInfo("key2"));
+
+		IQObject qobj_d = qtIndex.findQObject(new String[]{ "D" });
+		assertNotNull(qobj_d);
+		assertEquals("value1", qobj_d.getClassInfo("key1")); // inherited
+		assertEquals("overridden value", qobj_d.getClassInfo("key2"));
+	}
+
 	// #include "junit-QObject.hh"
 	// template <typename T> class QList {};
 	// class QString {};