Example usage for org.aspectj.apache.bcel.generic MethodGen addExceptionHandler

Introduction

In this page you can find the example usage for org.aspectj.apache.bcel.generic MethodGen addExceptionHandler.

Prototype

public CodeExceptionGen addExceptionHandler(InstructionHandle start_pc, InstructionHandle end_pc,
        InstructionHandle handler_pc, ObjectType catch_type) 

Source Link

Document

Add an exception handler, i.e., specify region where a handler is active and an instruction where the actual handling is done.

Usage

From source file:br.jabuti.probe.desktop.DefaultProbeInsert.java

License:Open Source License

/**
 * This method wraps a given method code between two pieces of code: one to be executed before
 * the method and other after, as a finaly clause. The instrumentation will use the next 2 free
 * local variable, so the code to be inserted should not use them.
 * //  w  w w.  ja  v  a2  s.co m
 * @param jv - The JavaClass where to find the method
 * @param name - the method name
 * @param sig - method signature
 * @param cfg - the control flow graph of the method
 * @param before - the code to be inserted before the method code
 * @param after - the code to be inserted after the method
 */
static public JavaClass wrapMethod(JavaClass jv, String name, String sig,
        // CFG cfg,
        String before, String after) {
    ClassGen cg = new ClassGen(jv);
    ConstantPoolGen cp = cg.getConstantPool();

    Method[] methods = cg.getMethods();
    int i;
    for (i = 0; i < methods.length; i++) {
        String n = methods[i].getName();
        String s = methods[i].getSignature();
        if (s.equals(sig) && n.equals(name))
            break;
    }
    if (i >= methods.length)
        return jv;
    MethodGen mg = new MethodGen(methods[i], cg.getClassName(), cp);
    try {
        int nextLocal = mg.getMaxLocals();
        ASMInstrumenter gi = new ASMInstrumenter(mg, cg, cp);

        InstructionList iList = mg.getInstructionList();

        // pega instrucao inicial
        InstructionHandle first = iList.getStart();
        // System.out.println("First: " + first);
        // System.out.println(iList);
        gi.insertBefore(first, " NOP " + (before == null ? "" : before));
        // System.out.println(iList);

        // iList = mg.getInstructionList();
        InstructionHandle preambulo = iList.getStart();
        // System.out.println("Preambulo: " + preambulo);

        // ultima instrucao do metodo
        InstructionHandle last = iList.getEnd();
        // System.out.println("Last: " + last);

        // comeca a inserir o tratador de instrucoes
        gi.insertAfter(last, " astore " + (nextLocal + 1));
        // iList = mg.getInstructionList();
        InstructionHandle catcher = iList.getEnd();
        gi.insertAfter(catcher, " jsr l1 aload " + (nextLocal + 1) + " athrow " + " l1: NOP ");

        // System.out.println("catcher: " + catcher);

        // comeca a inserir o codigo do finally
        // iList = mg.getInstructionList();
        InstructionHandle subroutine = iList.getEnd();
        // System.out.println("subroutine: " + subroutine);

        String finali = " astore " + nextLocal;
        finali += after;
        finali += " ret " + nextLocal;
        gi.insertAfter(subroutine, finali);

        // iList = mg.getInstructionList();

        InstructionHandle nx = first, curr;
        mg.getMethod();

        // para cada return no codigo faz uma chamada aa subrotina
        do {
            curr = nx;
            BranchInstruction jsr = new JSR(subroutine);
            Instruction ins = curr.getInstruction();
            if (ins instanceof ReturnInstruction) {
                gi.insertBefore(curr, jsr);
            }
            nx = curr.getNext();
        } while (curr != last);

        // e finalmente, coloca o tratador de excees para todo
        // o cdigo orignal
        iList = mg.getInstructionList();
        mg.addExceptionHandler(preambulo, last, catcher, (ObjectType) null);
    } catch (ParseException e) {
        System.err.println("Parser error " + e.getMessage());
    }

    mg.setMaxStack();
    mg.setMaxLocals();
    methods[i] = mg.getMethod();
    cg.setMethods(methods);
    return (cg.getJavaClass());
}

---