Add internal API for filters and filter for synchronized statement (#501)

1 files changed, 90 insertions, 0 deletions

diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/SynchronizedFilter.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/SynchronizedFilter.java
new file mode 100644
index 00000000..65e763d5
--- /dev/null
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/SynchronizedFilter.java
@@ -0,0 +1,90 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2017 Mountainminds GmbH & Co. KG and Contributors
+ * 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:
+ *    Evgeny Mandrikov - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.internal.analysis.filter;
+
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.TryCatchBlockNode;
+
+/**
+ * Filters code that is generated for synchronized statement.
+ */
+public final class SynchronizedFilter implements IFilter {
+
+	public void filter(MethodNode methodNode, IFilterOutput output) {
+		for (TryCatchBlockNode tryCatch : methodNode.tryCatchBlocks) {
+			if (tryCatch.type != null) {
+				continue;
+			}
+			if (tryCatch.start == tryCatch.handler) {
+				continue;
+			}
+			final AbstractInsnNode to = new Matcher(tryCatch.handler).match();
+			if (to == null) {
+				continue;
+			}
+			output.ignore(tryCatch.handler, to);
+		}
+	}
+
+	private static class Matcher {
+		private final AbstractInsnNode start;
+		private AbstractInsnNode cursor;
+
+		private Matcher(final AbstractInsnNode start) {
+			this.start = start;
+		}
+
+		private AbstractInsnNode match() {
+			if (nextIsEcj() || nextIsJavac()) {
+				return cursor;
+			}
+			return null;
+		}
+
+		private boolean nextIsJavac() {
+			cursor = start;
+			return nextIs(Opcodes.ASTORE) && nextIs(Opcodes.ALOAD)
+					&& nextIs(Opcodes.MONITOREXIT) && nextIs(Opcodes.ALOAD)
+					&& nextIs(Opcodes.ATHROW);
+		}
+
+		private boolean nextIsEcj() {
+			cursor = start;
+			return nextIs(Opcodes.ALOAD) && nextIs(Opcodes.MONITOREXIT)
+					&& nextIs(Opcodes.ATHROW);
+		}
+
+		/**
+		 * Moves {@link #cursor} to next instruction and returns
+		 * <code>true</code> if it has given opcode.
+		 */
+		private boolean nextIs(int opcode) {
+			next();
+			return cursor != null && cursor.getOpcode() == opcode;
+		}
+
+		/**
+		 * Moves {@link #cursor} to next instruction.
+		 */
+		private void next() {
+			do {
+				cursor = cursor.getNext();
+			} while (cursor != null
+					&& (cursor.getType() == AbstractInsnNode.FRAME
+							|| cursor.getType() == AbstractInsnNode.LABEL
+							|| cursor.getType() == AbstractInsnNode.LINE));
+		}
+	}
+
+}