java-bytecode-asm

问题 I am using ASM 5.0.3 byte code library with Tomcat 8 and JDK 8. Also I am using ClassWriter classWriter = new ClassWriter(classReader, ClassWriter.COMPUTE_FRAMES); and classReader.accept(myClassVisitor, ClassReader.SKIP_FRAMES); Below exception is thrown by ASM Caused by: java.lang.VerifyError: Operand stack overflow Exception Details: Location: org/apache/tomcat/websocket/server/WsServerContainer.addEndpoint(Ljavax/websocket/server/ServerEndpointConfig;)V @0: aload_0 Reason: Exceeded max

问题 I am using ASM 5.0.3 byte code library with Tomcat 8 and JDK 8. Also I am using ClassWriter classWriter = new ClassWriter(classReader, ClassWriter.COMPUTE_FRAMES); and classReader.accept(myClassVisitor, ClassReader.SKIP_FRAMES); Below exception is thrown by ASM Caused by: java.lang.VerifyError: Operand stack overflow Exception Details: Location: org/apache/tomcat/websocket/server/WsServerContainer.addEndpoint(Ljavax/websocket/server/ServerEndpointConfig;)V @0: aload_0 Reason: Exceeded max

问题 I'm trying to generate bytecode wich will create object instance without code initialization logic. Actually I want to reproduce generateSerializationConstructor behavior. { mv = cw.visitMethod(ACC_PUBLIC, "newObjectInstance", "()Ljava/lang/Object;", null, null); mv.visitCode(); mv.visitTypeInsn(NEW, classNameInternal); mv.visitInsn(DUP); classNameInternal = "java/lang/Object"; mv.visitMethodInsn(INVOKESPECIAL, classNameInternal, "<init>", "()V"); mv.visitInsn(ARETURN); mv.visitMaxs(0, 0); mv

问题 I followed the sample code in the "3.2.6 Inline Method“ in the http://asm.ow2.org/current/asm-transformations.pdf, to inline a MethodNode to a call site. My problem is that there are some unexpected instructions shown in the generated bytecode after inlining (these bytecodes are inconsistent to my code), and the problem only exists when an ifeq is after inlineed method body and the variable on the stack is loaded by xLoad. I still have not found the root cause for the issue. Now i am start to

问题 I am trying to write a program that takes a .class file and collects all the methods of the .class file as well as the contents of each method. Here is my code public class ClassReaderTest1 { public static void main(String[] args) throws Exception{ InputStream in = new FileInputStream("*.class"); ClassReader reader = new ClassReader(in); ClassNode classNode = new ClassNode(); reader.accept(classNode,0); @SuppressWarnings("unchecked") final List<MethodNode> methods = classNode.methods; for

问题 I have the following class: import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.commons.AdviceAdapter; public class NotEmptyAdvice extends AdviceAdapter { protected NotEmptyAdvice(final MethodVisitor visitor, final int i, final String s, final String s2) { super(visitor, i, s, s2); } @Override protected void onMethodEnter() { super.mv.visitVarInsn(ALOAD, 1); super.mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "isEmpty", "()Z" ); super.mv.visitVarInsn(IFEQ, 1); super.mv

问题 I have the following class: import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.commons.AdviceAdapter; public class NotEmptyAdvice extends AdviceAdapter { protected NotEmptyAdvice(final MethodVisitor visitor, final int i, final String s, final String s2) { super(visitor, i, s, s2); } @Override protected void onMethodEnter() { super.mv.visitVarInsn(ALOAD, 1); super.mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "isEmpty", "()Z" ); super.mv.visitVarInsn(IFEQ, 1); super.mv

问题 We wrote a simple PostScript interpreter in Java and want to optimize it by generating bytecode directly for specific parts of source code. For this we need to load the object from the context of the Java bytecode context. Specify such object in the signature of the generated bytecode method is not good, because they may be in a large amount in our case. In Java Asm we have method public void visitLdcInsn(Object cst) It visits a LDC instruction. Parameter cst - the constant to be loaded on

问题 So I have some classes into which "dummy method calls" have been inserted; i.e. static methods in a dedicated class that have an empty body. The idea is to take the arguments that were pushed to the stack prior to the method invokation, store them in local variables, then replace the method invocation with the actual implementation. To see how locals are handled, I run A.java package asmvisit; public class A { long y; public long doSomething(int x, A a){ if(a == null){ this.y = (long)x;

问题 So I have some classes into which "dummy method calls" have been inserted; i.e. static methods in a dedicated class that have an empty body. The idea is to take the arguments that were pushed to the stack prior to the method invokation, store them in local variables, then replace the method invocation with the actual implementation. To see how locals are handled, I run A.java package asmvisit; public class A { long y; public long doSomething(int x, A a){ if(a == null){ this.y = (long)x;