/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file: * * ASM: a very small and fast Java bytecode manipulation framework * Copyright (c) 2000-2011 INRIA, France Telecom * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ package jdk.internal.org.objectweb.asm; /** * A visitor to visit a Java method. The methods of this class must be * called in the following order: [ visitAnnotationDefault ] ( * visitAnnotation | visitParameterAnnotation | * visitAttribute )* [ visitCode ( visitFrame | * visitXInsn | visitLabel | visitTryCatchBlock | * visitLocalVariable | visitLineNumber )* visitMaxs ] * visitEnd. In addition, the visitXInsn * and visitLabel methods must be called in the sequential order of * the bytecode instructions of the visited code, visitTryCatchBlock * must be called before the labels passed as arguments have been * visited, and the visitLocalVariable and visitLineNumber * methods must be called after the labels passed as arguments have been * visited. * * @author Eric Bruneton */ public abstract class MethodVisitor { /** * The ASM API version implemented by this visitor. The value of this field * must be one of {@link Opcodes#ASM4}. */ protected final int api; /** * The method visitor to which this visitor must delegate method calls. May * be null. */ protected MethodVisitor mv; /** * Constructs a new {@link MethodVisitor}. * * @param api the ASM API version implemented by this visitor. Must be one * of {@link Opcodes#ASM4}. */ public MethodVisitor(final int api) { this(api, null); } /** * Constructs a new {@link MethodVisitor}. * * @param api the ASM API version implemented by this visitor. Must be one * of {@link Opcodes#ASM4}. * @param mv the method visitor to which this visitor must delegate method * calls. May be null. */ public MethodVisitor(final int api, final MethodVisitor mv) { /*if (api != Opcodes.ASM4) { throw new IllegalArgumentException(); }*/ this.api = api; this.mv = mv; } // ------------------------------------------------------------------------- // Annotations and non standard attributes // ------------------------------------------------------------------------- /** * Visits the default value of this annotation interface method. * * @return a visitor to the visit the actual default value of this * annotation interface method, or null if this visitor * is not interested in visiting this default value. The 'name' * parameters passed to the methods of this annotation visitor are * ignored. Moreover, exacly one visit method must be called on this * annotation visitor, followed by visitEnd. */ public AnnotationVisitor visitAnnotationDefault() { if (mv != null) { return mv.visitAnnotationDefault(); } return null; } /** * Visits an annotation of this method. * * @param desc the class descriptor of the annotation class. * @param visible true if the annotation is visible at runtime. * @return a visitor to visit the annotation values, or null if * this visitor is not interested in visiting this annotation. */ public AnnotationVisitor visitAnnotation(String desc, boolean visible) { if (mv != null) { return mv.visitAnnotation(desc, visible); } return null; } /** * Visits an annotation of a parameter this method. * * @param parameter the parameter index. * @param desc the class descriptor of the annotation class. * @param visible true if the annotation is visible at runtime. * @return a visitor to visit the annotation values, or null if * this visitor is not interested in visiting this annotation. */ public AnnotationVisitor visitParameterAnnotation( int parameter, String desc, boolean visible) { if (mv != null) { return mv.visitParameterAnnotation(parameter, desc, visible); } return null; } /** * Visits a non standard attribute of this method. * * @param attr an attribute. */ public void visitAttribute(Attribute attr) { if (mv != null) { mv.visitAttribute(attr); } } /** * Starts the visit of the method's code, if any (i.e. non abstract method). */ public void visitCode() { if (mv != null) { mv.visitCode(); } } /** * Visits the current state of the local variables and operand stack * elements. This method must(*) be called just before any * instruction i that follows an unconditional branch instruction * such as GOTO or THROW, that is the target of a jump instruction, or that * starts an exception handler block. The visited types must describe the * values of the local variables and of the operand stack elements just * before i is executed.

(*) this is mandatory only * for classes whose version is greater than or equal to * {@link Opcodes#V1_6 V1_6}.

Packed frames are basically * "deltas" from the state of the previous frame (very first frame is * implicitly defined by the method's parameters and access flags): * * @param type the type of this stack map frame. Must be * {@link Opcodes#F_NEW} for expanded frames, or * {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND}, * {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or * {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for compressed * frames. * @param nLocal the number of local variables in the visited frame. * @param local the local variable types in this frame. This array must not * be modified. Primitive types are represented by * {@link Opcodes#TOP}, {@link Opcodes#INTEGER}, * {@link Opcodes#FLOAT}, {@link Opcodes#LONG}, * {@link Opcodes#DOUBLE},{@link Opcodes#NULL} or * {@link Opcodes#UNINITIALIZED_THIS} (long and double are * represented by a single element). Reference types are represented * by String objects (representing internal names), and uninitialized * types by Label objects (this label designates the NEW instruction * that created this uninitialized value). * @param nStack the number of operand stack elements in the visited frame. * @param stack the operand stack types in this frame. This array must not * be modified. Its content has the same format as the "local" array. * @throws IllegalStateException if a frame is visited just after another * one, without any instruction between the two (unless this frame * is a Opcodes#F_SAME frame, in which case it is silently ignored). */ public void visitFrame( int type, int nLocal, Object[] local, int nStack, Object[] stack) { if (mv != null) { mv.visitFrame(type, nLocal, local, nStack, stack); } } // ------------------------------------------------------------------------- // Normal instructions // ------------------------------------------------------------------------- /** * Visits a zero operand instruction. * * @param opcode the opcode of the instruction to be visited. This opcode is * either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, * ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, * FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD, * DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE, * DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP, * DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD, * DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, * FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, * LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, * I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, * I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, * FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, * MONITORENTER, or MONITOREXIT. */ public void visitInsn(int opcode) { if (mv != null) { mv.visitInsn(opcode); } } /** * Visits an instruction with a single int operand. * * @param opcode the opcode of the instruction to be visited. This opcode is * either BIPUSH, SIPUSH or NEWARRAY. * @param operand the operand of the instruction to be visited.
When * opcode is BIPUSH, operand value should be between Byte.MIN_VALUE * and Byte.MAX_VALUE.
When opcode is SIPUSH, operand value * should be between Short.MIN_VALUE and Short.MAX_VALUE.
When * opcode is NEWARRAY, operand value should be one of * {@link Opcodes#T_BOOLEAN}, {@link Opcodes#T_CHAR}, * {@link Opcodes#T_FLOAT}, {@link Opcodes#T_DOUBLE}, * {@link Opcodes#T_BYTE}, {@link Opcodes#T_SHORT}, * {@link Opcodes#T_INT} or {@link Opcodes#T_LONG}. */ public void visitIntInsn(int opcode, int operand) { if (mv != null) { mv.visitIntInsn(opcode, operand); } } /** * Visits a local variable instruction. A local variable instruction is an * instruction that loads or stores the value of a local variable. * * @param opcode the opcode of the local variable instruction to be visited. * This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, * LSTORE, FSTORE, DSTORE, ASTORE or RET. * @param var the operand of the instruction to be visited. This operand is * the index of a local variable. */ public void visitVarInsn(int opcode, int var) { if (mv != null) { mv.visitVarInsn(opcode, var); } } /** * Visits a type instruction. A type instruction is an instruction that * takes the internal name of a class as parameter. * * @param opcode the opcode of the type instruction to be visited. This * opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF. * @param type the operand of the instruction to be visited. This operand * must be the internal name of an object or array class (see {@link * Type#getInternalName() getInternalName}). */ public void visitTypeInsn(int opcode, String type) { if (mv != null) { mv.visitTypeInsn(opcode, type); } } /** * Visits a field instruction. A field instruction is an instruction that * loads or stores the value of a field of an object. * * @param opcode the opcode of the type instruction to be visited. This * opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD. * @param owner the internal name of the field's owner class (see {@link * Type#getInternalName() getInternalName}). * @param name the field's name. * @param desc the field's descriptor (see {@link Type Type}). */ public void visitFieldInsn(int opcode, String owner, String name, String desc) { if (mv != null) { mv.visitFieldInsn(opcode, owner, name, desc); } } /** * Visits a method instruction. A method instruction is an instruction that * invokes a method. * * @param opcode the opcode of the type instruction to be visited. This * opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC * or INVOKEINTERFACE. * @param owner the internal name of the method's owner class (see {@link * Type#getInternalName() getInternalName}). * @param name the method's name. * @param desc the method's descriptor (see {@link Type Type}). */ public void visitMethodInsn(int opcode, String owner, String name, String desc) { if (mv != null) { mv.visitMethodInsn(opcode, owner, name, desc); } } /** * Visits an invokedynamic instruction. * * @param name the method's name. * @param desc the method's descriptor (see {@link Type Type}). * @param bsm the bootstrap method. * @param bsmArgs the bootstrap method constant arguments. Each argument * must be an {@link Integer}, {@link Float}, {@link Long}, * {@link Double}, {@link String}, {@link Type} or {@link Handle} * value. This method is allowed to modify the content of the array * so a caller should expect that this array may change. */ public void visitInvokeDynamicInsn(String name, String desc, Handle bsm, Object... bsmArgs) { if (mv != null) { mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs); } } /** * Visits a jump instruction. A jump instruction is an instruction that may * jump to another instruction. * * @param opcode the opcode of the type instruction to be visited. This * opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, * IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, * IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL. * @param label the operand of the instruction to be visited. This operand * is a label that designates the instruction to which the jump * instruction may jump. */ public void visitJumpInsn(int opcode, Label label) { if (mv != null) { mv.visitJumpInsn(opcode, label); } } /** * Visits a label. A label designates the instruction that will be visited * just after it. * * @param label a {@link Label Label} object. */ public void visitLabel(Label label) { if (mv != null) { mv.visitLabel(label); } } // ------------------------------------------------------------------------- // Special instructions // ------------------------------------------------------------------------- /** * Visits a LDC instruction. Note that new constant types may be added in * future versions of the Java Virtual Machine. To easily detect new * constant types, implementations of this method should check for * unexpected constant types, like this: * 
     * if (cst instanceof Integer) {
     *   // ...
     * } else if (cst instanceof Float) {
     *   // ...
     * } else if (cst instanceof Long) {
     *   // ...
     * } else if (cst instanceof Double) {
     *   // ...
     * } else if (cst instanceof String) {
     *   // ...
     * } else if (cst instanceof Type) {
     *   int sort = ((Type) cst).getSort();
     *   if (sort == Type.OBJECT) {
     *     // ...
     *   } else if (sort == Type.ARRAY) {
     *     // ...
     *   } else if (sort == Type.METHOD) {
     *     // ...
     *   } else {
     *     // throw an exception
     *   }
     * } else if (cst instanceof Handle) {
     *   // ...
     * } else {
     *   // throw an exception
     * }
* * @param cst the constant to be loaded on the stack. This parameter must be * a non null {@link Integer}, a {@link Float}, a {@link Long}, a * {@link Double}, a {@link String}, a {@link Type} of OBJECT or ARRAY * sort for .class constants, for classes whose version is * 49.0, a {@link Type} of METHOD sort or a {@link Handle} for * MethodType and MethodHandle constants, for classes whose version * is 51.0. */ public void visitLdcInsn(Object cst) { if (mv != null) { mv.visitLdcInsn(cst); } } /** * Visits an IINC instruction. * * @param var index of the local variable to be incremented. * @param increment amount to increment the local variable by. */ public void visitIincInsn(int var, int increment) { if (mv != null) { mv.visitIincInsn(var, increment); } } /** * Visits a TABLESWITCH instruction. * * @param min the minimum key value. * @param max the maximum key value. * @param dflt beginning of the default handler block. * @param labels beginnings of the handler blocks. labels[i] is * the beginning of the handler block for the min + i key. */ public void visitTableSwitchInsn(int min, int max, Label dflt, Label... labels) { if (mv != null) { mv.visitTableSwitchInsn(min, max, dflt, labels); } } /** * Visits a LOOKUPSWITCH instruction. * * @param dflt beginning of the default handler block. * @param keys the values of the keys. * @param labels beginnings of the handler blocks. labels[i] is * the beginning of the handler block for the keys[i] key. */ public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) { if (mv != null) { mv.visitLookupSwitchInsn(dflt, keys, labels); } } /** * Visits a MULTIANEWARRAY instruction. * * @param desc an array type descriptor (see {@link Type Type}). * @param dims number of dimensions of the array to allocate. */ public void visitMultiANewArrayInsn(String desc, int dims) { if (mv != null) { mv.visitMultiANewArrayInsn(desc, dims); } } // ------------------------------------------------------------------------- // Exceptions table entries, debug information, max stack and max locals // ------------------------------------------------------------------------- /** * Visits a try catch block. * * @param start beginning of the exception handler's scope (inclusive). * @param end end of the exception handler's scope (exclusive). * @param handler beginning of the exception handler's code. * @param type internal name of the type of exceptions handled by the * handler, or null to catch any exceptions (for "finally" * blocks). * @throws IllegalArgumentException if one of the labels has already been * visited by this visitor (by the {@link #visitLabel visitLabel} * method). */ public void visitTryCatchBlock(Label start, Label end, Label handler, String type) { if (mv != null) { mv.visitTryCatchBlock(start, end, handler, type); } } /** * Visits a local variable declaration. * * @param name the name of a local variable. * @param desc the type descriptor of this local variable. * @param signature the type signature of this local variable. May be * null if the local variable type does not use generic * types. * @param start the first instruction corresponding to the scope of this * local variable (inclusive). * @param end the last instruction corresponding to the scope of this local * variable (exclusive). * @param index the local variable's index. * @throws IllegalArgumentException if one of the labels has not already * been visited by this visitor (by the * {@link #visitLabel visitLabel} method). */ public void visitLocalVariable( String name, String desc, String signature, Label start, Label end, int index) { if (mv != null) { mv.visitLocalVariable(name, desc, signature, start, end, index); } } /** * Visits a line number declaration. * * @param line a line number. This number refers to the source file from * which the class was compiled. * @param start the first instruction corresponding to this line number. * @throws IllegalArgumentException if start has not already been * visited by this visitor (by the {@link #visitLabel visitLabel} * method). */ public void visitLineNumber(int line, Label start) { if (mv != null) { mv.visitLineNumber(line, start); } } /** * Visits the maximum stack size and the maximum number of local variables * of the method. * * @param maxStack maximum stack size of the method. * @param maxLocals maximum number of local variables for the method. */ public void visitMaxs(int maxStack, int maxLocals) { if (mv != null) { mv.visitMaxs(maxStack, maxLocals); } } /** * Visits the end of the method. This method, which is the last one to be * called, is used to inform the visitor that all the annotations and * attributes of the method have been visited. */ public void visitEnd() { if (mv != null) { mv.visitEnd(); } } }