Do not generate stack map frames for Java 5 bytecode

Fixes #55

README.md

@@ -208,6 +208,12 @@ optimizations to that mechanism may break Retrolambda.
 Version History
 ---------------
 
+### Upcoming
+
+- Fixed Retrolambda generating stack map frames for Java 5 bytecode,
+  causing some bytecode tools to fail
+  ([Issue #55](https://github.com/orfjackal/retrolambda/issues/55))
+
 ### Retrolambda 2.0.2 (2015-04-14)
 
 - Fixed a hack which caused lambdas in interfaces to be backported twice,

end-to-end-tests/end-to-end-tests.iml

@@ -6,6 +6,7 @@
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
       <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />

end-to-end-tests/pom.xml

@@ -40,6 +40,23 @@
     </dependencies>
 
     <build>
+        <testResources>
+            <testResource>
+                <directory>src/test/resources</directory>
+                <filtering>true</filtering>
+                <includes>
+                    <include>*.properties</include>
+                </includes>
+            </testResource>
+            <testResource>
+                <directory>src/test/resources</directory>
+                <filtering>false</filtering>
+                <excludes>
+                    <exclude>*.properties</exclude>
+                </excludes>
+            </testResource>
+        </testResources>
+
         <plugins>
 
             <!-- Don't deploy the tests to Maven Central -->

end-to-end-tests/src/test/java/net/orfjackal/retrolambda/test/Java5BytecodeTest.java

@@ -0,0 +1,47 @@
+// Copyright © 2013-2015 Esko Luontola <www.orfjackal.net>
+// This software is released under the Apache License 2.0.
+// The license text is at http://www.apache.org/licenses/LICENSE-2.0
+
+package net.orfjackal.retrolambda.test;
+
+import com.google.common.io.CharStreams;
+import org.apache.commons.lang.SystemUtils;
+import org.junit.Test;
+
+import java.io.*;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+public class Java5BytecodeTest {
+
+    @Test
+    public void does_not_generate_stack_map_tables_for_Java_5() throws IOException {
+        String javapOutput = javap(Dummy.class);
+
+        if (SystemUtils.isJavaVersionAtLeast(1.6f)) {
+            assertThat(javapOutput, containsString("StackMap"));
+        } else {
+            assertThat(javapOutput, not(containsString("StackMap")));
+        }
+    }
+
+    private static String javap(Class<?> aClass) throws IOException {
+        Process process = new ProcessBuilder()
+                .directory(TestEnv.testClassesDir)
+                .command("javap", "-v", "-p", aClass.getName())
+                .redirectErrorStream(true)
+                .start();
+        return CharStreams.toString(new InputStreamReader(process.getInputStream()));
+    }
+
+
+    public static class Dummy {
+        public Dummy() {
+            // cause this method to have a stack map table
+            for (int i = 0; i < 3; i++) {
+                System.out.println(i);
+            }
+        }
+    }
+}

end-to-end-tests/src/test/java/net/orfjackal/retrolambda/test/TestEnv.java

@@ -0,0 +1,23 @@
+// Copyright © 2013-2015 Esko Luontola <www.orfjackal.net>
+// This software is released under the Apache License 2.0.
+// The license text is at http://www.apache.org/licenses/LICENSE-2.0
+
+package net.orfjackal.retrolambda.test;
+
+import java.io.*;
+import java.util.Properties;
+
+public class TestEnv {
+
+    public static final File testClassesDir;
+
+    static {
+        Properties p = new Properties();
+        try (InputStream in = TestEnv.class.getResourceAsStream("/testing.properties")) {
+            p.load(in);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        testClassesDir = new File(p.getProperty("testClassesDir"));
+    }
+}

end-to-end-tests/src/test/resources/testing.properties

@@ -0,0 +1 @@
+testClassesDir=${project.build.testOutputDirectory}

retrolambda/src/main/java/net/orfjackal/retrolambda/LowerBytecodeVersion.java

@@ -1,10 +1,10 @@
-// Copyright © 2013-2014 Esko Luontola <www.orfjackal.net>
+// Copyright © 2013-2015 Esko Luontola <www.orfjackal.net>
 // This software is released under the Apache License 2.0.
 // The license text is at http://www.apache.org/licenses/LICENSE-2.0
 
 package net.orfjackal.retrolambda;
 
-import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.*;
 
 import static org.objectweb.asm.Opcodes.ASM5;
 
@@ -24,4 +24,26 @@ public void visit(int version, int access, String name, String signature, String
         }
         super.visit(version, access, name, signature, superName, interfaces);
     }
+
+    @Override
+    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
+        MethodVisitor next = super.visitMethod(access, name, desc, signature, exceptions);
+        if (targetVersion <= Opcodes.V1_5) {
+            return new RemoveMethodFrames(next);
+        } else {
+            return next;
+        }
+    }
+
+    private static class RemoveMethodFrames extends MethodVisitor {
+
+        public RemoveMethodFrames(MethodVisitor next) {
+            super(Opcodes.ASM5, next);
+        }
+
+        @Override
+        public void visitFrame(int type, int nLocal, Object[] local, int nStack, Object[] stack) {
+            // remove frame
+        }
+    }
 }