List of usage examples for org.objectweb.asm Opcodes NULL
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From source file:org.jboss.byteman.agent.adapter.RuleGeneratorAdapter.java
License:Open Source License
private void dumpType(StringBuffer buffer, Object t) { if (t == Opcodes.TOP) { buffer.append("TOP"); } else if (t == null) { buffer.append("null"); } else if (t == Opcodes.INTEGER) { buffer.append("int"); } else if (t == Opcodes.FLOAT) { buffer.append("float"); } else if (t == Opcodes.DOUBLE) { buffer.append("double"); } else if (t == Opcodes.LONG) { buffer.append("long"); } else if (t == Opcodes.NULL) { buffer.append("null"); } else if (t == Opcodes.UNINITIALIZED_THIS) { buffer.append("uninit_this"); } else if (t instanceof String) { buffer.append((String) t); } else {// w ww . j a v a2s . c o m buffer.append(((Label) t).getOffset()); } }
From source file:org.jboss.byteman.agent.adapter.RuleGeneratorAdapter.java
License:Open Source License
public void visitFrame(final int type, final int nLocal, final Object[] local, final int nStack, final Object[] stack) { if (type != Opcodes.F_NEW) { // uncompressed frame throw new IllegalStateException("ClassReader.accept() should be called with EXPAND_FRAMES flag"); }//from w w w . java 2s . c om // dumpFrame(nLocal, local, nStack, stack); // adjust the local types array int toRemove = localTypes.size(); for (int i = toRemove; i > 0; i--) { localTypes.remove(i - 1); } int nextLocal = 0; for (int i = 0; i < nLocal; i++) { Object t = local[i]; if (t == Opcodes.TOP) { localTypes.add(null); } else if (t == null) { localTypes.add(null); } else if (t == Opcodes.INTEGER) { localTypes.add(Type.INT_TYPE); } else if (t == Opcodes.FLOAT) { localTypes.add(Type.FLOAT_TYPE); } else if (t == Opcodes.DOUBLE) { localTypes.add(Type.DOUBLE_TYPE); nextLocal++; localTypes.add(null); } else if (t == Opcodes.LONG) { localTypes.add(Type.LONG_TYPE); nextLocal++; localTypes.add(null); } else if (t == Opcodes.NULL) { localTypes.add(null); } else if (t == Opcodes.UNINITIALIZED_THIS) { localTypes.add(null); } else if (t instanceof String) { localTypes.add(Type.getObjectType((String) t)); } else { localTypes.add(null); } nextLocal++; } this.nextLocal = nextLocal; mv.visitFrame(type, nLocal, local, nStack, stack); }
From source file:org.spongepowered.asm.util.Locals.java
License:MIT License
/** * <p>Attempts to identify available locals at an arbitrary point in the * bytecode specified by node.</p> * /*w ww . j a v a 2 s. co m*/ * <p>This method builds an approximate view of the locals available at an * arbitrary point in the bytecode by examining the following features in * the bytecode:</p> * <ul> * <li>Any available stack map frames</li> * <li>STORE opcodes</li> * <li>The local variable table</li> * </ul> * * <p>Inference proceeds by walking the bytecode from the start of the * method looking for stack frames and STORE opcodes. When either of these * is encountered, an attempt is made to cross-reference the values in the * stack map or STORE opcode with the value in the local variable table * which covers the code range. Stack map frames overwrite the entire * simulated local variable table with their own value types, STORE opcodes * overwrite only the local slot to which they pertain. Values in the * simulated locals array are spaced according to their size (unlike the * representation in FrameNode) and this TOP, NULL and UNINTITIALIZED_THIS * opcodes will be represented as null values in the simulated frame.</p> * * <p>This code does not currently simulate the prescribed JVM behaviour * where overwriting the second slot of a DOUBLE or LONG actually * invalidates the DOUBLE or LONG stored in the previous location, so we * have to hope (for now) that this behaviour isn't emitted by the compiler * or any upstream transformers. I may have to re-think this strategy if * this situation is encountered in the wild.</p> * * @param classNode ClassNode containing the method, used to initialise the * implicit "this" reference in simple methods with no stack frames * @param method MethodNode to explore * @param node Node indicating the position at which to determine the locals * state. The locals will be enumerated UP TO the specified node, so * bear in mind that if the specified node is itself a STORE opcode, * then we will be looking at the state of the locals PRIOR to its * invocation * @return A sparse array containing a view (hopefully) of the locals at the * specified location */ public static LocalVariableNode[] getLocalsAt(ClassNode classNode, MethodNode method, AbstractInsnNode node) { LocalVariableNode[] frame = new LocalVariableNode[method.maxLocals]; int local = 0, index = 0; // Initialise implicit "this" reference in non-static methods if ((method.access & Opcodes.ACC_STATIC) == 0) { frame[local++] = new LocalVariableNode("this", classNode.name, null, null, null, 0); } // Initialise method arguments for (Type argType : Type.getArgumentTypes(method.desc)) { frame[local] = new LocalVariableNode("arg" + index++, argType.toString(), null, null, null, local); local += argType.getSize(); } for (Iterator<AbstractInsnNode> iter = method.instructions.iterator(); iter.hasNext();) { AbstractInsnNode insn = iter.next(); if (insn instanceof FrameNode) { FrameNode frameNode = (FrameNode) insn; // localPos tracks the location in the frame node's locals list, which doesn't leave space for TOP entries for (int localPos = 0, framePos = 0; framePos < frame.length; framePos++, localPos++) { // Get the local at the current position in the FrameNode's locals list final Object localType = (localPos < frameNode.local.size()) ? frameNode.local.get(localPos) : null; if (localType instanceof String) { // String refers to a reference type frame[framePos] = Locals.getLocalVariableAt(classNode, method, node, framePos); } else if (localType instanceof Integer) { // Integer refers to a primitive type or other marker boolean isMarkerType = localType == Opcodes.UNINITIALIZED_THIS || localType == Opcodes.TOP || localType == Opcodes.NULL; boolean is32bitValue = localType == Opcodes.INTEGER || localType == Opcodes.FLOAT; boolean is64bitValue = localType == Opcodes.DOUBLE || localType == Opcodes.LONG; if (isMarkerType) { frame[framePos] = null; } else if (is32bitValue || is64bitValue) { frame[framePos] = Locals.getLocalVariableAt(classNode, method, node, framePos); if (is64bitValue) { framePos++; frame[framePos] = null; // TOP } } else { throw new RuntimeException( "Unrecognised locals opcode " + localType + " in locals array at position " + localPos + " in " + classNode.name + "." + method.name + method.desc); } } else if (localType == null) { frame[framePos] = null; } else { throw new RuntimeException("Invalid value " + localType + " in locals array at position " + localPos + " in " + classNode.name + "." + method.name + method.desc); } } } else if (insn instanceof VarInsnNode) { VarInsnNode varNode = (VarInsnNode) insn; frame[varNode.var] = Locals.getLocalVariableAt(classNode, method, node, varNode.var); } else if (insn == node) { break; } } return frame; }