/** Instrument the specified method to replace mapped calls. */ public void instrument_method(Method m, MethodGen mg) { // Loop through each instruction, making substitutions InstructionList il = mg.getInstructionList(); for (InstructionHandle ih = il.getStart(); ih != null; ) { if (debug_instrument_inst.enabled()) { debug_instrument_inst.log("instrumenting instruction %s%n", ih); // ih.getInstruction().toString(pool.getConstantPool())); } InstructionList new_il = null; // Remember the next instruction to process InstructionHandle next_ih = ih.getNext(); // Get the translation for this instruction (if any) new_il = xform_inst(mg, ih.getInstruction()); if (debug_instrument_inst.enabled()) debug_instrument_inst.log(" new inst: %s%n", new_il); // If this instruction was modified, replace it with the new // instruction list. If this instruction was the target of any // jumps or line numbers , replace them with the first // instruction in the new list replace_instructions(il, ih, new_il); ih = next_ih; } }
CFG createCFG(String className) throws ClassNotFoundException { CFG cfg = new CFG(); JavaClass jc = Repository.lookupClass(className); ClassGen cg = new ClassGen(jc); ConstantPoolGen cpg = cg.getConstantPool(); for (Method m : cg.getMethods()) { MethodGen mg = new MethodGen(m, cg.getClassName(), cpg); InstructionList il = mg.getInstructionList(); InstructionHandle[] handles = il.getInstructionHandles(); int prev = 0; for (InstructionHandle ih : handles) { int position = ih.getPosition(); cfg.addNode(position, m, jc); Instruction inst = ih.getInstruction(); boolean br = inst.getName().contains("if") || inst.getName().contains("goto"); boolean ret = inst.getName().contains("return"); boolean stat = inst.getName().contains("invokestatic"); int len = inst.getLength(); if (stat) { int index = inst.toString(true).indexOf(" "); String name = inst.toString(true).substring(index + 1); int tar = Integer.valueOf(name); INVOKESTATIC inv = new INVOKESTATIC(tar); name = inv.getMethodName(cpg); Method m2 = null; Method[] tm = cg.getMethods(); for (int i = 0; i < tm.length; i++) { if (tm[i].getName().equals(name)) { m2 = tm[i]; } } cfg.addEdge(position, m, jc, 0, m2, jc); cfg.addEdge(-1, m2, jc, position + len, m, jc); } if (!ret && !stat) { cfg.addEdge(position, position + len, m, jc); } if (br) { cfg.addEdge(position, position + len, m, jc); IF_ICMPGE comp = new IF_ICMPGE(ih); String name = comp.getTarget().toString(false); int index = name.indexOf(">"); name = name.substring(index + 2); int tar = Integer.valueOf(name); cfg.addEdge(position, tar, m, jc); } if (ret) { cfg.addEdge(position, -1, m, jc); } prev = position; } System.out.println(cfg.toString()); } return cfg; }
/** Start the method's visit. */ public void start() { if (!mg.isAbstract() && !mg.isNative()) { for (InstructionHandle ih = mg.getInstructionList().getStart(); ih != null; ih = ih.getNext()) { Instruction i = ih.getInstruction(); if (!visitInstruction(i)) i.accept(this); } updateExceptionHandlers(); } }
/** * Replace instruction ih in list il with the instructions in new_il. If new_il is null, do * nothing */ protected static void replace_instructions( InstructionList il, InstructionHandle ih, InstructionList new_il) { if ((new_il == null) || new_il.isEmpty()) return; // If there is only one new instruction, just replace it in the handle if (new_il.getLength() == 1) { ih.setInstruction(new_il.getEnd().getInstruction()); return; } // Get the start and end instruction of the new instructions InstructionHandle new_end = new_il.getEnd(); InstructionHandle new_start = il.insert(ih, new_il); // Move all of the branches from the old instruction to the new start il.redirectBranches(ih, new_start); // Move other targets to the new instuctions. if (ih.hasTargeters()) { for (InstructionTargeter it : ih.getTargeters()) { if (it instanceof LineNumberGen) { it.updateTarget(ih, new_start); } else if (it instanceof LocalVariableGen) { it.updateTarget(ih, new_end); } else if (it instanceof CodeExceptionGen) { CodeExceptionGen exc = (CodeExceptionGen) it; if (exc.getStartPC() == ih) exc.updateTarget(ih, new_start); else if (exc.getEndPC() == ih) exc.updateTarget(ih, new_end); else if (exc.getHandlerPC() == ih) exc.setHandlerPC(new_start); else System.out.printf("Malformed CodeException: %s%n", exc); } else { System.out.printf("unexpected target %s%n", it); } } } // Remove the old handle. There should be no targeters left to it. try { il.delete(ih); } catch (Exception e) { throw new Error("Can't delete instruction", e); } }