Java tutorial
/* * Copyright 2015 the original author or authors. * @https://github.com/scouter-project/scouter * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package scouter.agent.asm; import org.objectweb.asm.ClassVisitor; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; import org.objectweb.asm.Type; import org.objectweb.asm.commons.LocalVariablesSorter; import scouter.agent.ClassDesc; import scouter.agent.Configure; import scouter.agent.asm.util.AsmUtil; import scouter.agent.asm.util.HookingSet; import scouter.agent.trace.TraceMain; import java.util.List; public class CapArgsASM implements IASM, Opcodes { private List<HookingSet> target = HookingSet.getHookingMethodSet(Configure.getInstance().hook_args_patterns); public ClassVisitor transform(ClassVisitor cv, String className, ClassDesc classDesc) { if (Configure.getInstance()._hook_cap_enabled == false) { return cv; } for (int i = 0; i < target.size(); i++) { HookingSet mset = target.get(i); if (mset.classMatch.include(className)) { return new CapArgsCV(cv, mset, className); } } return cv; } } // /////////////////////////////////////////////////////////////////////////// class CapArgsCV extends ClassVisitor implements Opcodes { public String className; private HookingSet mset; public CapArgsCV(ClassVisitor cv, HookingSet mset, String className) { super(ASM7, cv); this.mset = mset; this.className = className; } @Override public MethodVisitor visitMethod(int access, String methodName, String desc, String signature, String[] exceptions) { MethodVisitor mv = super.visitMethod(access, methodName, desc, signature, exceptions); if (mv == null || mset.isA(methodName, desc) == false) { return mv; } if (AsmUtil.isSpecial(methodName)) { return mv; } return new CapArgsMV(access, desc, mv, Type.getArgumentTypes(desc), (access & ACC_STATIC) != 0, className, methodName, desc); } } // /////////////////////////////////////////////////////////////////////////// class CapArgsMV extends LocalVariablesSorter implements Opcodes { private static final String CLASS = TraceMain.class.getName().replace('.', '/'); private static final String METHOD = "capArgs"; private static final String SIGNATURE = "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Object;[Ljava/lang/Object;)V"; private Type[] paramTypes; private boolean isStatic; private String className; private String methodName; private String methodDesc; public CapArgsMV(int access, String desc, MethodVisitor mv, Type[] paramTypes, boolean isStatic, String classname, String methodname, String methoddesc) { super(ASM7, access, desc, mv); this.paramTypes = paramTypes; this.isStatic = isStatic; this.className = classname; this.methodName = methodname; this.methodDesc = methoddesc; } @Override public void visitCode() { int sidx = isStatic ? 0 : 1; int arrVarIdx = newLocal(Type.getType("[Ljava/lang/Object;")); AsmUtil.PUSH(mv, paramTypes.length); mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); mv.visitVarInsn(Opcodes.ASTORE, arrVarIdx); for (int i = 0; i < paramTypes.length; i++) { Type type = paramTypes[i]; mv.visitVarInsn(Opcodes.ALOAD, arrVarIdx); AsmUtil.PUSH(mv, i); switch (type.getSort()) { case Type.BOOLEAN: mv.visitVarInsn(Opcodes.ILOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Boolean", "valueOf", "(Z)Ljava/lang/Boolean;", false); break; case Type.BYTE: mv.visitVarInsn(Opcodes.ILOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Byte", "valueOf", "(B)Ljava/lang/Byte;", false); break; case Type.CHAR: mv.visitVarInsn(Opcodes.ILOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Character", "valueOf", "(C)Ljava/lang/Character;", false); break; case Type.SHORT: mv.visitVarInsn(Opcodes.ILOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Short", "valueOf", "(S)Ljava/lang/Short;", false); break; case Type.INT: mv.visitVarInsn(Opcodes.ILOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Integer", "valueOf", "(I)Ljava/lang/Integer;", false); break; case Type.LONG: mv.visitVarInsn(Opcodes.LLOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;", false); break; case Type.FLOAT: mv.visitVarInsn(Opcodes.FLOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Float", "valueOf", "(F)Ljava/lang/Float;", false); break; case Type.DOUBLE: mv.visitVarInsn(Opcodes.DLOAD, sidx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Double", "valueOf", "(D)Ljava/lang/Double;", false); break; default: mv.visitVarInsn(Opcodes.ALOAD, sidx); } mv.visitInsn(Opcodes.AASTORE); sidx += type.getSize(); } AsmUtil.PUSH(mv, className); AsmUtil.PUSH(mv, methodName); AsmUtil.PUSH(mv, methodDesc); if (isStatic) { AsmUtil.PUSHNULL(mv); } else { mv.visitVarInsn(Opcodes.ALOAD, 0); } mv.visitVarInsn(Opcodes.ALOAD, arrVarIdx); mv.visitMethodInsn(Opcodes.INVOKESTATIC, CLASS, METHOD, SIGNATURE, false); mv.visitCode(); } }