Bug 509898 - CPPSemantics.isReachableFromAst is slow and is causing UI

freezes

Added caching to the isReachableFromAst method.

Change-Id: Ifb321f0ffde5a3068001711be222d8dadc0990cc

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

@@ -32,6 +32,9 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunctionType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPNamespace;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPNamespaceScope;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPParameter;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPSpecialization;
+import org.eclipse.cdt.core.index.IIndexBinding;
+import org.eclipse.cdt.core.index.IIndexFileSet;
 import org.eclipse.cdt.core.parser.ParserLanguage;
 import org.eclipse.cdt.core.parser.util.ArrayUtil;
 import org.eclipse.cdt.internal.core.dom.Linkage;
@@ -48,13 +51,15 @@ import org.eclipse.cdt.internal.core.parser.scanner.InternalFileContent;
 public class CPPASTTranslationUnit extends ASTTranslationUnit implements ICPPASTTranslationUnit, IASTAmbiguityParent {
     private CPPNamespaceScope fScope;
     private ICPPNamespace fBinding;
-	private final CPPScopeMapper fScopeMapper= new CPPScopeMapper(this);
+	private final CPPScopeMapper fScopeMapper;
 	private CPPASTAmbiguityResolver fAmbiguityResolver;
 
 	// Caches
-	private Map<ICPPClassType, FinalOverriderMap> fFinalOverriderMapCache = new HashMap<>();
+	private final Map<ICPPClassType, FinalOverriderMap> fFinalOverriderMapCache = new HashMap<>();
+	private final Map<IBinding, Boolean> fBindingReachabilityCache = new HashMap<>();
 
 	public CPPASTTranslationUnit() {
+		fScopeMapper= new CPPScopeMapper(this);
 	}
 
 	@Override
@@ -234,4 +239,43 @@ public class CPPASTTranslationUnit extends ASTTranslationUnit implements ICPPAST
 	public ICPPClassTemplatePartialSpecialization mapToAST(ICPPClassTemplatePartialSpecialization indexSpec) {
 		return fScopeMapper.mapToAST(indexSpec);
 	}
+
+	/**
+	 * Checks if a binding is an AST binding, or is reachable from the AST through includes.
+	 * The binding is assumed to belong to the AST, if it is not an IIndexBinding and not
+	 * a specialization of an IIndexBinding.
+	 *
+	 * @param binding
+	 * @return {@code true} if the {@code binding} is reachable from the AST.
+	 */
+	public boolean isReachableFromAst(IBinding binding) {
+		Boolean cachedValue = fBindingReachabilityCache.get(binding);
+		if (cachedValue != null)
+			return cachedValue;
+
+		IIndexBinding indexBinding = null;
+		if (binding instanceof IIndexBinding) {
+			indexBinding = (IIndexBinding) binding;
+		}
+		if (binding instanceof ICPPSpecialization) {
+			binding = ((ICPPSpecialization) binding).getSpecializedBinding();
+			if (binding instanceof IIndexBinding) {
+				indexBinding = (IIndexBinding) binding;
+			}
+		}
+		boolean reachable;
+		if (indexBinding == null) {
+			// We don't check if the binding really belongs to this AST assuming that
+			// the caller doesn't deal with two ASTs at a time.
+			reachable = true;
+		} else {
+			IIndexFileSet indexFileSet = getIndexFileSet();
+			IIndexFileSet astFileSet = getASTFileSet();
+			reachable = indexFileSet != null &&
+					(indexFileSet.containsDeclaration(indexBinding) ||
+					 astFileSet.containsDeclaration(indexBinding));
+		}
+		fBindingReachabilityCache.put(binding, reachable);
+		return reachable;
+	}
 }

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

@@ -1104,7 +1104,7 @@ public class CPPSemantics {
 				if (item instanceof IBinding) {
 					IBinding binding = (IBinding) item;
 					CPPASTTranslationUnit tu = data.getTranslationUnit();
-					if (!isFromIndex(binding) || tu == null || isReachableFromAst(tu, binding)) {
+					if (!isFromIndex(binding) || tu == null || tu.isReachableFromAst(binding)) {
 						return true;
 					}
 				}
@@ -2257,7 +2257,7 @@ public class CPPSemantics {
 	 * the two bindings have the same relevance; -1 if <code>b1</code> is less relevant than
 	 * <code>b2</code>.
 	 */
-	static int compareByRelevance(IASTTranslationUnit tu, IBinding b1, IBinding b2) {
+	static int compareByRelevance(CPPASTTranslationUnit tu, IBinding b1, IBinding b2) {
 		boolean b1FromIndex= isFromIndex(b1);
 		boolean b2FromIndex= isFromIndex(b2);
 		if (b1FromIndex != b2FromIndex) {
@@ -2265,8 +2265,8 @@ public class CPPSemantics {
 		} else if (b1FromIndex) {
 			// Both are from index.
 			if (tu != null) {
-				boolean b1Reachable= isReachableFromAst(tu, b1);
+				boolean b1Reachable= tu.isReachableFromAst(b1);
-				boolean b2Reachable= isReachableFromAst(tu, b2);
+				boolean b2Reachable= tu.isReachableFromAst(b2);
 				if (b1Reachable != b2Reachable) {
 					return b1Reachable ? 1 : -1;
 				}
@@ -2285,7 +2285,7 @@ public class CPPSemantics {
 			return false;
 		final CPPASTTranslationUnit tu = data.getTranslationUnit();
 		if (tu != null) {
-			return !isReachableFromAst(tu, b2) && isReachableFromAst(tu, type);
+			return !tu.isReachableFromAst(b2) && tu.isReachableFromAst(type);
 		}
 		return false;
 	}
@@ -2306,12 +2306,12 @@ public class CPPSemantics {
 			}
 		}
 
-		if (!isReachableFromAst(tu, type)) {
+		if (!tu.isReachableFromAst(type)) {
 			return false;
 		}
 
 		for (IFunction fn : fns) {
-			if (isReachableFromAst(tu, fn)) {
+			if (tu.isReachableFromAst(fn)) {
 				return false;	// function from ast
 			}
 		}
@@ -2368,12 +2368,12 @@ public class CPPSemantics {
 			}
 			// Everything is from the index
 			final CPPASTTranslationUnit tu = data.getTranslationUnit();
-			if (!isReachableFromAst(tu, obj)) {
+			if (!tu.isReachableFromAst(obj)) {
 				return -1; // obj not reachable
 			}
 
 			for (IFunction fn : fns) {
-				if (isReachableFromAst(tu, fn)) {
+				if (tu.isReachableFromAst(fn)) {
 					return 0; // obj reachable, 1 function reachable
 				}
 			}
@@ -2403,40 +2403,10 @@ public class CPPSemantics {
 	 * Checks if a binding is an AST binding, or is reachable from the AST through includes.
 	 * The binding is assumed to belong to the AST, if it is not an IIndexBinding and not
 	 * a specialization of an IIndexBinding.
+	 *
 	 * @param ast
 	 * @param binding
-	 * @return <code>true</code> if the <code>binding</code> is reachable from <code>ast</code>.
+	 * @return {@code true} if the {@code binding}> is reachable from {@code ast}.
-	 */
-	private static boolean isReachableFromAst(IASTTranslationUnit ast, IBinding binding) {
-		IIndexBinding indexBinding = null;
-		if (binding instanceof IIndexBinding) {
-			indexBinding = (IIndexBinding) binding;
-		}
-		if (binding instanceof ICPPSpecialization) {
-			binding = ((ICPPSpecialization) binding).getSpecializedBinding();
-			if (binding instanceof IIndexBinding) {
-				indexBinding = (IIndexBinding) binding;
-			}
-		}
-		if (indexBinding == null) {
-			// We don't check if the binding really belongs to the AST specified by the ast
-			// parameter assuming that the caller doesn't deal with two ASTs at a time.
-			return true;
-		}
-		IIndexFileSet indexFileSet = ast.getIndexFileSet();
-		IIndexFileSet astFileSet = ast.getASTFileSet();
-		return indexFileSet != null &&
-				(indexFileSet.containsDeclaration(indexBinding) ||
-				 astFileSet.containsDeclaration(indexBinding));
-	}
-
-	/**
-	 * Checks if a binding is an AST binding, or is reachable from the AST through includes.
-	 * The binding is assumed to belong to the AST, if it is not an IIndexBinding and not
-	 * a specialization of an IIndexBinding.
-	 * @param ast
-	 * @param binding
-	 * @return <code>true</code> if the <code>binding</code> is reachable from <code>ast</code>.
 	 */
 	private static boolean isReachableFromAst(IASTTranslationUnit ast, IName name) {
 		if (!(name instanceof IIndexName)) {
@@ -2750,7 +2720,7 @@ public class CPPSemantics {
 		}
 
 		// Try to instantiate a template
-		IASTTranslationUnit tu= data.getTranslationUnit();
+		CPPASTTranslationUnit tu= data.getTranslationUnit();
 		ICPPTemplateArgument[] tmplArgs= ICPPTemplateArgument.EMPTY_ARGUMENTS;
 		if (templateID instanceof ICPPASTTemplateId) {
 			tmplArgs = CPPTemplates.createTemplateArgumentArray((ICPPASTTemplateId) templateID);
@@ -3322,7 +3292,7 @@ public class CPPSemantics {
 		ICPPFunction result= null;
 		ICPPFunctionTemplate resultTemplate= null;
 		boolean isAmbiguous= false;
-		final IASTTranslationUnit tu= point.getTranslationUnit();
+		final CPPASTTranslationUnit tu= (CPPASTTranslationUnit) point.getTranslationUnit();
 		for (IFunction fn : fns) {
 			try {
 				if (fn instanceof ICPPFunctionTemplate) {

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

@@ -20,7 +20,6 @@ import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUti
 import org.eclipse.cdt.core.dom.ast.DOMException;
 import org.eclipse.cdt.core.dom.ast.IASTExpression.ValueCategory;
 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.IFunction;
 import org.eclipse.cdt.core.dom.ast.IType;
@@ -30,6 +29,7 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunctionTemplate;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunctionType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPMethod;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPSpecialization;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPASTTranslationUnit;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPTemplates.TypeSelection;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.Cost.DeferredUDC;
 
@@ -131,7 +131,7 @@ class FunctionCost {
 	/**
 	 * Compares this function call cost to another one.
 	 */
-	public int compareTo(IASTTranslationUnit tu, FunctionCost other) throws DOMException {
+	public int compareTo(CPPASTTranslationUnit tu, FunctionCost other) throws DOMException {
 		if (other == null)
 			return -1;