variable definition and assignment detect asm bytecode

I am trying to use the ASM bytecode tree API for static analysis of Java Code. I have a ClassNode cn, MethodNode m and the list of instructions in that method say InsnList list.

Suppose for a given instruction( i.e. AbstractInsnNode) s, I need to find all the definitions/assignments of the variable at s in the above instruction list. To make it more clear, suppose a variable var is defined and initialized on line 2, then a开发者_JAVA百科ssigned some other value on line number 8 and then used on line number 12. Line number 12 is my s, in this case. Also, assume lots of conditional code in the lines in between.

Is this possible to do with ASM? How??

Thanks and Regards, SJ

For clarity,

public void funcToAnalyze(String k, SomeClass v) {
            int numIter = 0;

            /*
               Do cool stuff here.... modifies member variables and passed params too
            */

    if (v.rank > 1 || numIter>200) {
        magicFunction(k, 1);
    }
}

Here, suppose the conditional is the JumpInsnNode (current instruction) and I need to find if (and where) any of the variables in the conditional (v.rank and numIter in this case) are modified or assigned anywhere in the above code. Keep it simple, just member variables (no static function or delegation to function of another class).

The SourceInterpreter computes SourceValues for each Frame for a corresponding instruction in MethodNode. Basically it tells which instructions could place value to a given variable or stack slot.

Also see ASM User Guide for more information about ASM analysis package.

However if you just need to detect if certain variable been assigned, then all you have to do is to look for xSTORE instructions with corresponding variable indexes.