8025636: Hide lambda proxy frames in stacktraces
Reviewed-by: jrose, forax, jfranck, vlivanov
--- a/jdk/src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java Mon Feb 16 19:16:50 2015 -0500
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java Tue Feb 17 10:09:26 2015 +0100
@@ -285,6 +285,7 @@
// Forward the SAM method
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, samMethodName,
samMethodType.toMethodDescriptorString(), null, null);
+ mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
new ForwardingMethodGenerator(mv).generate(samMethodType);
// Forward the bridges
@@ -292,6 +293,7 @@
for (MethodType mt : additionalBridges) {
mv = cw.visitMethod(ACC_PUBLIC|ACC_BRIDGE, samMethodName,
mt.toMethodDescriptorString(), null, null);
+ mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
new ForwardingMethodGenerator(mv).generate(mt);
}
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/invoke/lambda/LambdaStackTrace.java Tue Feb 17 10:09:26 2015 +0100
@@ -0,0 +1,204 @@
+/*
+ * 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 8025636
+ * @summary Synthetic frames should be hidden in exceptions
+ * @compile -XDignore.symbol.file LUtils.java LambdaStackTrace.java
+ * @run main LambdaStackTrace
+ */
+
+import jdk.internal.org.objectweb.asm.ClassWriter;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_ABSTRACT;
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_INTERFACE;
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC;
+import static jdk.internal.org.objectweb.asm.Opcodes.V1_7;
+
+public class LambdaStackTrace {
+
+ static File classes = new File(System.getProperty("test.classes"));
+
+ public static void main(String[] args) throws Exception {
+ testBasic();
+ testBridgeMethods();
+ }
+
+ /**
+ * Test the simple case
+ */
+ private static void testBasic() throws Exception {
+ try {
+ Runnable r = () -> {
+ throw new RuntimeException();
+ };
+ r.run();
+ } catch (Exception ex) {
+ // Before 8025636 the stacktrace would look like:
+ // at LambdaStackTrace.lambda$main$0(LambdaStackTrace.java:37)
+ // at LambdaStackTrace$$Lambda$1/1937396743.run(<Unknown>:1000000)
+ // at LambdaStackTrace.testBasic(LambdaStackTrace.java:40)
+ // at ...
+ //
+ // We are verifying that the middle frame above is gone.
+
+ verifyFrames(ex.getStackTrace(),
+ "LambdaStackTrace\\..*",
+ "LambdaStackTrace.testBasic");
+ }
+ }
+
+ /**
+ * Test the more complicated case with bridge methods.
+ *
+ * We set up the following interfaces:
+ *
+ * interface Maker {
+ * Object make();
+ * }
+ * interface StringMaker extends Maker {
+ * String make();
+ * }
+ *
+ * And we will use them like so:
+ *
+ * StringMaker sm = () -> { throw new RuntimeException(); };
+ * sm.make();
+ * ((Maker)m).make();
+ *
+ * The first call is a "normal" interface call, the second will use a
+ * bridge method. In both cases the generated lambda frame should
+ * be removed from the stack trace.
+ */
+ private static void testBridgeMethods() throws Exception {
+ // setup
+ generateInterfaces();
+ compileCaller();
+
+ // test
+ StackTraceElement[] frames = call("Caller", "callStringMaker");
+ verifyFrames(frames,
+ "Caller\\..*",
+ "Caller.callStringMaker");
+
+ frames = call("Caller", "callMaker");
+ verifyFrames(frames,
+ "Caller\\..*",
+ "Caller.callMaker");
+ }
+
+ private static void generateInterfaces() throws IOException {
+ // We can't let javac compile these interfaces because in > 1.8 it will insert
+ // bridge methods into the interfaces - we want code that looks like <= 1.7,
+ // so we generate it.
+ try (FileOutputStream fw = new FileOutputStream(new File(classes, "Maker.class"))) {
+ fw.write(generateMaker());
+ }
+ try (FileOutputStream fw = new FileOutputStream(new File(classes, "StringMaker.class"))) {
+ fw.write(generateStringMaker());
+ }
+ }
+
+ private static byte[] generateMaker() {
+ // interface Maker {
+ // Object make();
+ // }
+ ClassWriter cw = new ClassWriter(0);
+ cw.visit(V1_7, ACC_INTERFACE | ACC_ABSTRACT, "Maker", null, "java/lang/Object", null);
+ cw.visitMethod(ACC_PUBLIC | ACC_ABSTRACT, "make",
+ "()Ljava/lang/Object;", null, null);
+ cw.visitEnd();
+ return cw.toByteArray();
+ }
+
+ private static byte[] generateStringMaker() {
+ // interface StringMaker extends Maker {
+ // String make();
+ // }
+ ClassWriter cw = new ClassWriter(0);
+ cw.visit(V1_7, ACC_INTERFACE | ACC_ABSTRACT, "StringMaker", null, "java/lang/Object", new String[]{"Maker"});
+ cw.visitMethod(ACC_PUBLIC | ACC_ABSTRACT, "make",
+ "()Ljava/lang/String;", null, null);
+ cw.visitEnd();
+ return cw.toByteArray();
+ }
+
+
+ static void emitCode(File f) {
+ ArrayList<String> scratch = new ArrayList<>();
+ scratch.add("public class Caller {");
+ scratch.add(" public static void callStringMaker() {");
+ scratch.add(" StringMaker sm = () -> { throw new RuntimeException(); };");
+ scratch.add(" sm.make();");
+ scratch.add(" }");
+ scratch.add(" public static void callMaker() {");
+ scratch.add(" StringMaker sm = () -> { throw new RuntimeException(); };");
+ scratch.add(" ((Maker) sm).make();"); // <-- This will call the bridge method
+ scratch.add(" }");
+ scratch.add("}");
+ LUtils.createFile(f, scratch);
+ }
+
+ static void compileCaller() {
+ File caller = new File(classes, "Caller.java");
+ emitCode(caller);
+ LUtils.compile("-cp", classes.getAbsolutePath(), "-d", classes.getAbsolutePath(), caller.getAbsolutePath());
+ }
+
+ private static void verifyFrames(StackTraceElement[] stack, String... patterns) throws Exception {
+ for (int i = 0; i < patterns.length; i++) {
+ String cm = stack[i].getClassName() + "." + stack[i].getMethodName();
+ if (!cm.matches(patterns[i])) {
+ System.err.println("Actual trace did not match expected trace at frame " + i);
+ System.err.println("Expected frame patterns:");
+ for (int j = 0; j < patterns.length; j++) {
+ System.err.println(" " + j + ": " + patterns[j]);
+ }
+ System.err.println("Actual frames:");
+ for (int j = 0; j < patterns.length; j++) {
+ System.err.println(" " + j + ": " + stack[j]);
+ }
+ throw new Exception("Incorrect stack frames found");
+ }
+ }
+ }
+
+ private static StackTraceElement[] call(String clazz, String method) throws Exception {
+ Class<?> c = Class.forName(clazz);
+ try {
+ Method m = c.getDeclaredMethod(method);
+ m.invoke(null);
+ } catch(InvocationTargetException ex) {
+ return ex.getTargetException().getStackTrace();
+ }
+ throw new Exception("Expected exception to be thrown");
+ }
+}