bytecode

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;

问题 I'm adding new locals via newLocal from LocalVariableSorter . The method I'm adding the locals to is an instance method with a long parameter. I'm adding two locals; one long, one object. There are no other local vars in the sample code. As a result I would have expected the following slots / indexes: 0 - this 1 - the long param 3 - my 1st local added via `newLocal` - using two slots as it is a long 5 - my 2nd local added via `newLocal` What I do get as return from newLocal is 3 and 7 though.

问题 I'm trying to patch a class with ASM. I need to add some logic in a function. This logic needs a new local variable. Here is what I've done: class CreateHashTableMethodAdapter extends MethodAdapter { @Override public void visitMethodInsn(int opcode, String owner,String name, String desc){ System.out.println(opcode + "/" + owner + "/" + name + "/" + desc); if(opcode == Opcodes.INVOKESPECIAL && "javax/naming/InitialContext".equals(owner) && "<init>".equals(name) && "()V".equals(desc)){ System

问题 I work for a company that created firmware for several device using FreeRTOS. Lately our request for new features has surpassed how much work our firmware engineers are capable of, but we can't afford to hire anyone new right now either. Making even tiny changes requires firmware people to go in and modify things at a very low level. I've been looking for some sort of interpreted language project for FreeRTOS that would let us implement new features at a higher level. Ideally I would like to

问题 I work for a company that created firmware for several device using FreeRTOS. Lately our request for new features has surpassed how much work our firmware engineers are capable of, but we can't afford to hire anyone new right now either. Making even tiny changes requires firmware people to go in and modify things at a very low level. I've been looking for some sort of interpreted language project for FreeRTOS that would let us implement new features at a higher level. Ideally I would like to

问题 I have this Python code: import marshal, imp if imp.get_magic() == '\x03\xf3\r\n': __code = marshal.loads('c\x00\x00\x00\x00.....\x00d\x01\x00k\x00.....\t\t\r\x01') del marshal, imp exec __code The if condition checks wheter the Python version is the "right" version. Then marshal is used to load a string containing some code. First question: How was that string generated? Maybe compile() ? But how exactly? and second question: Can I decompile that string? How? 回答1: As far as how its created,

问题 I'm trying to intercept constructors annotated with @Inject . That worked fine in the context of a small unit test. However in the context of a DI container like Spring it fails with a ClassNotFoundException . I managed to narrow down on the root cause. Calling getDeclaredConstructors on the instrumented class will trigger this exception. Interestingly enough, if we first create an instance of that class, the problem disappears. For example: public class InterceptConstructorTest { @Test

问题 What's the difference between java bytecode astore_1 and astore_2 ? 回答1: The instructions astore_n , for small values of n , are just shorthand equivalents for astore n . Either version stores what's on top of the stack into local variable n . 回答2: astore_1 is the same as astore 1 , and astore_2 is the same as astore 2 , except that astore_1 and astore_2 are one byte each, whereas astore is a two-byte instruction. 来源： https://stackoverflow.com/questions/6983641/whats-the-difference-between

问题 What's the difference between java bytecode astore_1 and astore_2 ? 回答1: The instructions astore_n , for small values of n , are just shorthand equivalents for astore n . Either version stores what's on top of the stack into local variable n . 回答2: astore_1 is the same as astore 1 , and astore_2 is the same as astore 2 , except that astore_1 and astore_2 are one byte each, whereas astore is a two-byte instruction. 来源： https://stackoverflow.com/questions/6983641/whats-the-difference-between