bytecode

问题 I am trying to use ASM to count the individual bytecode instructions executed within a single function to build a histogram. I see there is a tool ByCounter that can do a similar task--but I do not have access to the source code. My understanding is the Java asm bytecode library can instrument classes, fields, methods, but examples for instrumenting an individual bytecode instruction are not to be found (though from ByCounter--it is found to be possible). If a tool like the JVMTI is better

问题 I'm working on a project that will trace method calls from a class within a package to any other class. It's important that I can identify concrete types, and I'd prefer to have a minimum tracing overhead. There is no restrictions on when the probe is triggered; it can be before or after a method has been called. ASM is currently used, but there is no requirement for it. The system is moving from AspectJ in order to allow dynamic attachment, so that's out. Below is the current situation. A

问题 Iam trying to execute an if statement with logical and symbol '&&'. Here is what iam trying to do: Μy stack in asm byteocode has the values 0 and 1 and i want to get a result with the 'logical and' which in our case it doesn't get into the if statement. I've tried Opcodes.IFEQ and Opcodes.IFNE instructions but the don't work.Same goes with '||' and '!' logical symbols Any ideas? Thanks in advaned. 回答1: Bytecode patterns for && and || Think about what a short-circuiting operator like && or ||

问题 Iam trying to execute an if statement with logical and symbol '&&'. Here is what iam trying to do: Μy stack in asm byteocode has the values 0 and 1 and i want to get a result with the 'logical and' which in our case it doesn't get into the if statement. I've tried Opcodes.IFEQ and Opcodes.IFNE instructions but the don't work.Same goes with '||' and '!' logical symbols Any ideas? Thanks in advaned. 回答1: Bytecode patterns for && and || Think about what a short-circuiting operator like && or ||

问题 How can I generate byetcode from Ruby 1.9?? My intent is to generate bytecode not the source code and ship it along with my application package. I am aware of the JRuby approach but I am facing certain issues there 回答1: Call BCEL library from JRuby. BCEL library is shipped with JDK. 来源： https://stackoverflow.com/questions/4014016/how-to-generate-bytecode-in-ruby-1-9

问题 In this trivial example, I want to factor out the i < 5 condition of a list comprehension into it's own function. I also want to eat my cake and have it too, and avoid the overhead of the CALL_FUNCTION bytecode/creating a new frame in the python virtual machine. Is there any way to factor out the conditions inside of a list comprehension into a new function but somehow get a disassembled result that avoids the large overhead of CALL_FUNCTION ? import dis import sys import timeit def my_filter

问题 I'll add my code to the end of this post. I'm using byteBuddy 1.7.9 and whatever ASM version comes with that. In a nutshell I have byte[] rawClass = ...; ClassReader cr = new ClassReader(rawClass); ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES); MethodAdder ma = new MethodAdder(Opcodes.ASM5,cw); cr.accept(ma,ClassReader.EXPAND_FRAMES); Where in MethodAdder , I want to add a static initialiser: @Override public MethodVisitor visitMethod(int access, String name, String desc,

问题 Is byte code an intermediate form of code between assembly code and machine code? And is bytecode the same as object code? This is what I think - High level language->Assembly language->Machine code/Object code (0s and 1s. different for different CPUs) Is it like this? High level language->Assembly language-> Byte code(will be taken care of by virtual machine, which will convert it into machine code) -> Machine code I've read this - SO- bytecode vs assembly language code , but need to

问题 Looked at using CGLib, ASM, BCEL (aspect) and Javassist to add a field to a class during runtime.... Just to get my head straight it looks like these bytecode manipulators don't update the actual class rather allow the user to only dump the modification (like with CGLib and the writeFile method). Was hoping I would find a solution that (a) loaded the class (rather than doing an InputStream with BCEL) and (b) updated the class. Maybe this is normal? Do people usually create a proxy and pass

问题 When ICS came out, there were several new extended-width bytecodes introduced. Most of these were for instructions to support jumbo ids. Here are some of these new instructions, taken from my ics/dalvik/opcode-gen/bytecode.txt: # # Extended-width opcodes # op 00ff const-class/jumbo 41c y type-ref continue|throw op 01ff check-cast/jumbo 41c n type-ref continue|throw op 02ff instance-of/jumbo 52c y type-ref continue|throw op 03ff new-instance/jumbo 41c y type-ref continue|throw op 04ff new