Bug 430282 - Limit recursion depth when processing inheritance

hierarchies

Change-Id: Ia9d9f379cb61e8d8bc8d1fb33f893fcd2a0688a2
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>
Reviewed-on: https://git.eclipse.org/r/23957
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
IP-Clean: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>

codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/AbstractClassInstantiationCheckerTest.java

@@ -365,4 +365,13 @@ public class AbstractClassInstantiationCheckerTest extends CheckerTestCase {
 		// Just check that codan runs without any exceptions being thrown.
 		loadCodeAndRun(getAboveComment());
 	}
+
+	//	template <int I>
+	//	struct S : S<I - 1> {};
+	//
+	//	S<1> waldo;
+	public void testMaxInstantiationDepth_430282() throws Exception {
+		// Just check that codan runs without any exceptions being thrown.
+		loadCodeAndRun(getAboveComment());
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/SemanticQueries.java

@@ -25,6 +25,7 @@ import org.eclipse.cdt.core.dom.ast.IBinding;
 import org.eclipse.cdt.core.dom.ast.IType;
 import org.eclipse.cdt.core.parser.util.CollectionUtils;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ClassTypeHelper;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPSemantics;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPTemplates;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil;
 
@@ -197,7 +198,8 @@ public class SemanticQueries {
 		private Map<ICPPClassType, FinalOverriderMap> virtualBaseCache = new HashMap<ICPPClassType, FinalOverriderMap>();
 		
 		public ICPPMethod[] collect(ICPPClassType root, IASTNode point) {
-			FinalOverriderMap finalOverriderMap = collectFinalOverriders(root, false, new HashSet<ICPPClassType>(), point);
+			FinalOverriderMap finalOverriderMap = collectFinalOverriders(root, false, new HashSet<ICPPClassType>(), 
+					CPPSemantics.MAX_INHERITANCE_DEPTH, point);
 			return finalOverriderMap.collectPureVirtualMethods();
 		}
 
@@ -212,7 +214,7 @@ public class SemanticQueries {
 		 * @return the computed final overrider map
 		 */
 		private FinalOverriderMap collectFinalOverriders(ICPPClassType classType, boolean isVirtualBase, 
-				Set<ICPPClassType> inheritanceChain, IASTNode point) {
+				Set<ICPPClassType> inheritanceChain, int maxdepth, IASTNode point) {
 			FinalOverriderMap result = new FinalOverriderMap();
 			
 			inheritanceChain.add(classType);
@@ -236,6 +238,12 @@ public class SemanticQueries {
 				if (inheritanceChain.contains(baseType))
 					continue;
 				
+				// Guard against infinite recursion in inheritance
+				// for example A<I> deriving from A<I - 1> without
+				// a base case to end the recursion.
+				if (maxdepth <= 0)
+					continue;
+				
 				// Collect final overrider information from the base class.
 				// If it's a virtual base class and we've already processed it
 				// in this class hierarchy, don't process it again.
@@ -243,11 +251,11 @@ public class SemanticQueries {
 				if (base.isVirtual()) {
 					baseOverriderMap = virtualBaseCache.get(baseType);
 					if (baseOverriderMap == null) {
-						baseOverriderMap = collectFinalOverriders(baseType, true, inheritanceChain, point);
+						baseOverriderMap = collectFinalOverriders(baseType, true, inheritanceChain, maxdepth - 1, point);
 						virtualBaseCache.put(baseType, baseOverriderMap);
 					}
 				} else {
-					baseOverriderMap = collectFinalOverriders(baseType, false, inheritanceChain, point);
+					baseOverriderMap = collectFinalOverriders(baseType, false, inheritanceChain, maxdepth - 1, point);
 				}
 			
 				// Merge final overrider information from base class into this class.

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/ClassTypeHelper.java

@@ -593,7 +593,8 @@ public class ClassTypeHelper {
 		for (ICPPBase base : bases) {
 			IBinding b= base.getBaseClass();
 			if (b instanceof ICPPClassType) {
-				findOverridden((ICPPClassType) b, point, mname, methodType, virtualInClass, result);
+				findOverridden((ICPPClassType) b, point, mname, methodType, virtualInClass, 
+						result, CPPSemantics.MAX_INHERITANCE_DEPTH);
 			}
 		}
 
@@ -611,7 +612,12 @@ public class ClassTypeHelper {
 	 */
 	private static boolean findOverridden(ICPPClassType classType, IASTNode point, char[] methodName,
 			ICPPFunctionType methodType, Map<ICPPClassType, Boolean> virtualInClass,
-			List<ICPPMethod> result) {
+			List<ICPPMethod> result, int maxdepth) {
+		// Prevent recursion due to a hierarchy of unbounded depth,
+		// e.g. A<I> deriving from A<I - 1>.
+		if (maxdepth <= 0)
+			return false;
+		
 		Boolean visitedBefore= virtualInClass.get(classType);
 		if (visitedBefore != null)
 			return visitedBefore;
@@ -629,13 +635,14 @@ public class ClassTypeHelper {
 			}
 		}
 
-		// Prevent recursion.
+		// Prevent recursion due to a class inheriting (directly or indirectly) from itself.
 		virtualInClass.put(classType, hasOverridden);
 		ICPPBase[] bases= getBases(classType, point);
 		for (ICPPBase base : bases) {
 			IBinding b= base.getBaseClass();
 			if (b instanceof ICPPClassType) {
-				if (findOverridden((ICPPClassType) b, point, methodName, methodType, virtualInClass, result)) {
+				if (findOverridden((ICPPClassType) b, point, methodName, methodType, virtualInClass, 
+						result, maxdepth - 1)) {
 					hasOverridden= true;
 				}
 			}