1/******************************************************************************* 2 * Copyright (c) 2009, 2017 Mountainminds GmbH & Co. KG and Contributors 3 * All rights reserved. This program and the accompanying materials 4 * are made available under the terms of the Eclipse Public License v1.0 5 * which accompanies this distribution, and is available at 6 * http://www.eclipse.org/legal/epl-v10.html 7 * 8 * Contributors: 9 * Marc R. Hoffmann - initial API and implementation 10 * 11 *******************************************************************************/ 12package org.jacoco.core.internal.flow; 13 14import org.jacoco.core.internal.instr.InstrSupport; 15import org.objectweb.asm.Label; 16import org.objectweb.asm.MethodVisitor; 17import org.objectweb.asm.tree.MethodNode; 18 19/** 20 * A {@link MethodVisitor} with additional methods to get probe insertion 21 * information. 22 */ 23public abstract class MethodProbesVisitor extends MethodVisitor { 24 25 /** 26 * New visitor instance without delegate visitor. 27 */ 28 public MethodProbesVisitor() { 29 this(null); 30 } 31 32 /** 33 * New visitor instance that delegates to the given visitor. 34 * 35 * @param mv 36 * optional next visitor in chain 37 */ 38 public MethodProbesVisitor(final MethodVisitor mv) { 39 super(InstrSupport.ASM_API_VERSION, mv); 40 } 41 42 /** 43 * Visits an unconditional probe that should be inserted at the current 44 * position. 45 * 46 * @param probeId 47 * id of the probe to insert 48 */ 49 @SuppressWarnings("unused") 50 public void visitProbe(final int probeId) { 51 } 52 53 /** 54 * Visits a jump instruction. A probe with the given id should be inserted 55 * in a way that it is executed only when the jump to the given label is 56 * executed. 57 * 58 * @param opcode 59 * the opcode of the type instruction to be visited. This opcode 60 * is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, 61 * IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, 62 * IF_ACMPEQ, IF_ACMPNE, GOTO, IFNULL or IFNONNULL. 63 * @param label 64 * the operand of the instruction to be visited. This operand is 65 * a label that designates the instruction to which the jump 66 * instruction may jump. 67 * @param probeId 68 * id of the probe 69 * @param frame 70 * stackmap frame status after the execution of the jump 71 * instruction. The instance is only valid with the call of this 72 * method. 73 * @see MethodVisitor#visitJumpInsn(int, Label) 74 */ 75 @SuppressWarnings("unused") 76 public void visitJumpInsnWithProbe(final int opcode, final Label label, 77 final int probeId, final IFrame frame) { 78 } 79 80 /** 81 * Visits a zero operand instruction with a probe. This event is used only 82 * for instructions that terminate the method. Therefore the probe must be 83 * inserted before the actual instruction. 84 * 85 * @param opcode 86 * the opcode of the instruction to be visited. This opcode is 87 * either IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, RETURN or 88 * ATHROW. 89 * @param probeId 90 * id of the probe 91 * @see MethodVisitor#visitInsn(int) 92 */ 93 @SuppressWarnings("unused") 94 public void visitInsnWithProbe(final int opcode, final int probeId) { 95 } 96 97 /** 98 * Visits a TABLESWITCH instruction with optional probes for each target 99 * label. Implementations can be optimized based on the fact that the same 100 * target labels will always have the same probe id within a call to this 101 * method. The probe id for each label can be obtained with 102 * {@link LabelInfo#getProbeId(Label)}. 103 * 104 * @param min 105 * the minimum key value. 106 * @param max 107 * the maximum key value. 108 * @param dflt 109 * beginning of the default handler block. 110 * @param labels 111 * beginnings of the handler blocks. <code>labels[i]</code> is 112 * the beginning of the handler block for the 113 * <code>min + i</code> key. 114 * @param frame 115 * stackmap frame status after the execution of the switch 116 * instruction. The instance is only valid with the call of this 117 * method. 118 * @see MethodVisitor#visitTableSwitchInsn(int, int, Label, Label[]) 119 */ 120 @SuppressWarnings("unused") 121 public void visitTableSwitchInsnWithProbes(final int min, final int max, 122 final Label dflt, final Label[] labels, final IFrame frame) { 123 } 124 125 /** 126 * Visits a LOOKUPSWITCH instruction with optional probes for each target 127 * label. Implementations can be optimized based on the fact that the same 128 * target labels will always have the same probe id within a call to this 129 * method. The probe id for each label can be obtained with 130 * {@link LabelInfo#getProbeId(Label)}. 131 * 132 * @param dflt 133 * beginning of the default handler block. 134 * @param keys 135 * the values of the keys. 136 * @param labels 137 * beginnings of the handler blocks. <code>labels[i]</code> is 138 * the beginning of the handler block for the 139 * <code>keys[i]</code> key. 140 * @param frame 141 * stackmap frame status after the execution of the switch 142 * instruction. The instance is only valid with the call of this 143 * method. 144 * @see MethodVisitor#visitLookupSwitchInsn(Label, int[], Label[]) 145 */ 146 @SuppressWarnings("unused") 147 public void visitLookupSwitchInsnWithProbes(final Label dflt, 148 final int[] keys, final Label[] labels, final IFrame frame) { 149 } 150 151 /** 152 * This method can be overwritten to hook into the process of emitting the 153 * instructions of this method as <code>visitX()</code> events. 154 * 155 * @param methodNode 156 * the content to emit 157 * @param methodVisitor 158 * A visitor to emit the content to. Note that this is not 159 * necessarily this visitor instance but some wrapper which 160 * calculates the probes. 161 */ 162 public void accept(final MethodNode methodNode, 163 final MethodVisitor methodVisitor) { 164 methodNode.accept(methodVisitor); 165 } 166 167} 168