8134759: jdb: Incorrect stepping inside finally block
Summary: Add LineNumberTable attribute for return bytecodes split around finally code
Reviewed-by: mcimadamore
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java Fri Oct 23 08:21:41 2015 +0530
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java Tue Oct 27 10:35:14 2015 +0100
@@ -1697,6 +1697,11 @@
public void visitReturn(JCReturn tree) {
int limit = code.nextreg;
final Env<GenContext> targetEnv;
+
+ /* Save and then restore the location of the return in case a finally
+ * is expanded (with unwind()) in the middle of our bytecodes.
+ */
+ int tmpPos = code.pendingStatPos;
if (tree.expr != null) {
Item r = genExpr(tree.expr, pt).load();
if (hasFinally(env.enclMethod, env)) {
@@ -1704,17 +1709,10 @@
r.store();
}
targetEnv = unwind(env.enclMethod, env);
+ code.pendingStatPos = tmpPos;
r.load();
code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
} else {
- /* If we have a statement like:
- *
- * return;
- *
- * we need to store the code.pendingStatPos value before generating
- * the finalizer.
- */
- int tmpPos = code.pendingStatPos;
targetEnv = unwind(env.enclMethod, env);
code.pendingStatPos = tmpPos;
code.emitop0(return_);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/linenumbers/FinallyLineNumberTest.java Tue Oct 27 10:35:14 2015 +0100
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8134759
+ * @summary Add LineNumberTable attribute for return bytecodes split around finally code
+ * @modules jdk.jdeps/com.sun.tools.classfile
+ */
+
+import com.sun.tools.classfile.ClassFile;
+import com.sun.tools.classfile.ConstantPoolException;
+import com.sun.tools.classfile.Method;
+import com.sun.tools.classfile.Attribute;
+import com.sun.tools.classfile.Code_attribute;
+import com.sun.tools.classfile.LineNumberTable_attribute;
+import com.sun.tools.classfile.LineNumberTable_attribute.Entry;
+
+import java.io.File;
+import java.io.IOException;
+
+public class FinallyLineNumberTest {
+ public static void main(String[] args) throws Exception {
+ // check that we have 5 consecutive entries for method()
+ Entry[] lines = findEntries();
+ if (lines == null) {
+ throw new Exception("finally line number table could not be loaded");
+ }
+ if (lines.length != 4) {
+ // Help debug
+ System.err.println("LineTable error, got lines:");
+ for (Entry e : lines) {
+ System.err.println(e.line_number);
+ }
+ throw new Exception("finally line number table incorrect: length=" + lines.length + " expected length=4");
+ }
+
+ // return null line, for the load null operation
+ int current = lines[0].line_number;
+ int first = current;
+
+ // finally line
+ current = lines[1].line_number;
+ if (current != first + 2) {
+ throw new Exception("finally line number table incorrect: got=" + current + " expected=" + (first + 2));
+ }
+
+ // return null line, for the return operation
+ current = lines[2].line_number;
+ if (current != first) {
+ throw new Exception("finally line number table incorrect: got=" + current + " expected=" + first);
+ }
+
+ // finally line, for when exception is thrown
+ current = lines[3].line_number;
+ if (current != first + 2) {
+ throw new Exception("finally line number table incorrect: got=" + current + " expected=" + (first + 2));
+ }
+ }
+
+ static Entry[] findEntries() throws IOException, ConstantPoolException {
+ ClassFile self = ClassFile.read(FinallyLineNumberTest.class.getResourceAsStream("FinallyLineNumberTest.class"));
+ for (Method m : self.methods) {
+ if ("method".equals(m.getName(self.constant_pool))) {
+ Code_attribute code_attribute = (Code_attribute)m.attributes.get(Attribute.Code);
+ for (Attribute at : code_attribute.attributes) {
+ if (Attribute.LineNumberTable.equals(at.getName(self.constant_pool))) {
+ return ((LineNumberTable_attribute)at).line_number_table;
+ }
+ }
+ }
+ }
+ return null;
+ }
+
+ // This method should get LineNumberTable entries for:
+ // *) The load of the null
+ // *) The finally code for when an exception is *not* thrown
+ // *) The actual return, which should have the same line as the load of the null
+ // *) The finally code for when an exception *is* thrown, should have the same line as above finally code
+ public static String method(int field) {
+ try {
+ return null;
+ } finally {
+ field+=1; // Dummy
+ }
+ }
+}