问题
I am getting expected ClassVerifyErrors when attempting to load a class i have generated using ASM. On further inspection i can see that the jvm is correct and that the method is talking about has an invalid MAX_STACK value. THe strange thing is am using the auto calculate the stack and max local options so this should not be a problem... The method with the invalid option is very simple and yet the result is bad bytecode.
I have written a class with the intended method and compared my asm generated class against what javac produces and the byte codes matchup with the only error being the max stack is 0 which is wrong while javac sets a value of 2.
Id like to avoid having to calculate tha max stack/locals myself.
回答1:
Max stack and variable calculation can produce the wrong results if bytecode is not valid. You can verify that by running generated code trough the CheckClassAdapter.
For example,
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
// generate code into cw instance...
PrintWriter pw = new PrintWriter(System.out);
CheckClassAdapter.verify(new ClassReader(cw.toByteArray()), true, pw);
来源：https://stackoverflow.com/questions/2235493/asm-from-objectweb-not-calculating-maxstack-correctly-even-though-classwriter