Examples with BranchInstruction org.apache.bcel.generic.BranchInstruction used on opensource projects

Example 6 with BranchInstruction

use of org.apache.bcel.generic.BranchInstruction in project jop by jop-devel.

the class InstructionInterpreter method getInEdges.

private List<Edge> getInEdges(InstructionList il, InstructionHandle ih) {
    List<Edge> edges = new LinkedList<Edge>();
    InstructionHandle prev = ih.getPrev();
    if (prev != null) {
        // check if we can fall through from prev instruction
        Instruction instr = prev.getInstruction();
        if (!(instr instanceof UnconditionalBranch || instr instanceof Select || instr instanceof ReturnInstruction)) {
            if (instr instanceof BranchInstruction) {
                edges.add(new Edge(prev, ih, EdgeType.FALSE_EDGE));
            } else {
                edges.add(new Edge(prev, ih, EdgeType.NORMAL_EDGE));
            }
        }
    }
    // flow graph explicitly
    for (InstructionHandle targeter = il.getStart(); targeter != null; targeter = targeter.getNext()) {
        //      for the instruction for the exception handler
        if (!(targeter.getInstruction() instanceof BranchInstruction))
            continue;
        BranchInstruction bi = (BranchInstruction) targeter.getInstruction();
        if (bi.containsTarget(ih)) {
            edges.add(new Edge(targeter, ih, EdgeType.TRUE_EDGE));
        }
    }
    return edges;
}

Example 7 with BranchInstruction

use of org.apache.bcel.generic.BranchInstruction in project jop by jop-devel.

the class InstructionInterpreter method getOutEdges.

private List<Edge> getOutEdges(InstructionHandle ih) {
    List<Edge> edges = new LinkedList<Edge>();
    Instruction instr = ih.getInstruction();
    if (instr instanceof BranchInstruction) {
        if (instr instanceof Select) {
            Select s = (Select) instr;
            InstructionHandle[] target = s.getTargets();
            for (InstructionHandle aTarget : target) {
                edges.add(new Edge(ih, aTarget, EdgeType.TRUE_EDGE));
            }
            edges.add(new Edge(ih, s.getTarget(), EdgeType.FALSE_EDGE));
        } else {
            BranchInstruction b = (BranchInstruction) instr;
            edges.add(new Edge(ih, b.getTarget(), EdgeType.TRUE_EDGE));
        }
    }
    // Check if we can fall through to the next instruction
    if (ih.getNext() != null && !(instr instanceof UnconditionalBranch || instr instanceof Select || instr instanceof ReturnInstruction)) {
        if (instr instanceof BranchInstruction) {
            edges.add(new Edge(ih, ih.getNext(), EdgeType.FALSE_EDGE));
        } else {
            edges.add(new Edge(ih, ih.getNext(), EdgeType.NORMAL_EDGE));
        }
    }
    if (instr instanceof ReturnInstruction) {
        edges.add(new Edge(ih, getExitInstruction(), EdgeType.EXIT_EDGE));
    }
    if (instr instanceof ATHROW) {
    // TODO should we handle this somehow? Insert edges to the exception handlers or to an return-by-exception
    //      exit instruction?
    // for now, just ignore them
    }
    //      but for now, we just ignore them too.. in a safe way :)
    if (instr instanceof RET || instr instanceof JSR || instr instanceof JSR_W) {
        throw new JavaClassFormatError("Unsupported instruction " + instr + " in " + methodInfo);
    }
    return edges;
}

Example 8 with BranchInstruction

use of org.apache.bcel.generic.BranchInstruction in project jop by jop-devel.

the class DFATool method loadMethod.

private void loadMethod(MethodInfo method) {
    MethodCode mcode = method.getCode();
    // TODO is there a better way to get an instruction handle? Do we need to keep the list somehow?
    InstructionHandle exit;
    exit = (InstructionHandle) method.getCustomValue(KEY_NOP);
    // we reuse the NOP if it exists, so that we can have multiple DFAs running at the same time
    if (exit == null) {
        exit = new InstructionList(new NOP()).getStart();
        // We do not really want to modify the REAL instruction list and append exit
        // (SH) Fixed :) Yep, we need the NOP somewhere, else doInvoke() will collect the wrong result state.
        //      But we can eliminate the NOP by adding the instruction not to the list, but instead to the
        //      MethodInfo, and also retrieve it from there.
        method.setCustomValue(KEY_NOP, exit);
    }
    this.getStatements().add(exit);
    // We do not modify the code, so we leave existing CFGs alone, just make sure the instruction list is uptodate
    InstructionList il = mcode.getInstructionList(true, false);
    // we need correct positions for the DFA cache serialization stuff
    il.setPositions();
    for (Iterator<?> l = il.iterator(); l.hasNext(); ) {
        InstructionHandle handle = (InstructionHandle) l.next();
        this.getStatements().add(handle);
        Instruction instr = handle.getInstruction();
        if (instr instanceof BranchInstruction) {
            if (instr instanceof Select) {
                Select s = (Select) instr;
                InstructionHandle[] target = s.getTargets();
                for (InstructionHandle aTarget : target) {
                    this.getFlow().addEdge(new FlowEdge(handle, aTarget, FlowEdge.TRUE_EDGE));
                }
                this.getFlow().addEdge(new FlowEdge(handle, s.getTarget(), FlowEdge.FALSE_EDGE));
            } else {
                BranchInstruction b = (BranchInstruction) instr;
                this.getFlow().addEdge(new FlowEdge(handle, b.getTarget(), FlowEdge.TRUE_EDGE));
            }
        }
        if (handle.getNext() != null && !(instr instanceof UnconditionalBranch || instr instanceof Select || instr instanceof ReturnInstruction)) {
            if (instr instanceof BranchInstruction) {
                this.getFlow().addEdge(new FlowEdge(handle, handle.getNext(), FlowEdge.FALSE_EDGE));
            } else {
                this.getFlow().addEdge(new FlowEdge(handle, handle.getNext(), FlowEdge.NORMAL_EDGE));
            }
        }
        if (instr instanceof ReturnInstruction) {
            this.getFlow().addEdge(new FlowEdge(handle, exit, FlowEdge.NORMAL_EDGE));
        }
    }
}