net.sourceforge.cobertura.instrument.pass3.TestUnitCodeProvider.java Source code

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/*
 * Cobertura - http://cobertura.sourceforge.net/
 *
 * Copyright (C) 2013 Steven Christou
 *
 * Note: This file is dual licensed under the GPL and the Apache
 * Source License (so that it can be used from both the main
 * Cobertura classes and the ant tasks).
 *
 * Cobertura is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * Cobertura 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Cobertura; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

package net.sourceforge.cobertura.instrument.pass3;

import net.sourceforge.cobertura.Cobertura;
import net.sourceforge.cobertura.coveragedata.TestUnitInformationHolder;

import org.objectweb.asm.*;

/**
 * 
 * For every single line of code we add the following:
 * 
 * Before instrumentation:
 * 1: public int foo() {
 * 2:  int x = 0;
 * 3:  x++;
 * 4:  return x;
 * 5: }
 * 
 * After instrumentation:
 * public int foo() {
 *   __cobertura_counters
 *         .get(2)
 *         .append(", " + net.sourceforge.cobertura.Cobertura.TestClassAndMethodNamesMerged);
 *   int x = 0; 
 *   __cobertura_counters
 *         .get(3)
 *         .append(", " + net.sourceforge.cobertura.Cobertura.TestClassAndMethodNamesMerged);
 *   x++;
 *   __cobertura_counters
 *         .get(4)
 *         .append(", " + net.sourceforge.cobertura.Cobertura.TestClassAndMethodNamesMerged);
 *   return x;
 * }
 * 
 * In future versions it might be best to switch from the ConcurrentHashMap to a more static approach.
 *
 * @author christ66
 */
public class TestUnitCodeProvider extends AbstractCodeProvider implements CodeProvider, Opcodes {

    /**
     * Type of the generated field, that is used to store counters
     */
    static final String COBERTURA_COUNTERS_FIELD_TYPE = "[Lnet/sourceforge/cobertura/coveragedata/TestUnitInformationHolder;";

    /**
     * Generates:
     * 
     */
    public void generateCodeThatIncrementsCoberturaCounterFromInternalVariable(MethodVisitor nextMethodVisitor,
            int lastJumpIdVariableIndex, String className) {
        nextMethodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
        nextMethodVisitor.visitFieldInsn(Opcodes.GETFIELD, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);
        nextMethodVisitor.visitVarInsn(Opcodes.ILOAD, lastJumpIdVariableIndex);
        nextMethodVisitor.visitInsn(Opcodes.DUP2);
        nextMethodVisitor.visitInsn(Opcodes.IALOAD);
        nextMethodVisitor.visitFieldInsn(Opcodes.GETSTATIC, Type.getInternalName(Cobertura.class),
                "TestClassAndMethodNamesMerged", "Ljava/lang/String;");
        nextMethodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                Type.getInternalName(TestUnitInformationHolder.class), "appendTestUnit", "(Ljava/lang/String;)V");
    }

    /**
     * Generates:
     * 
     */
    public void generateCodeThatIncrementsCoberturaCounter(MethodVisitor nextMethodVisitor, Integer counterId,
            String className) {

        nextMethodVisitor.visitVarInsn(ALOAD, 0);
        nextMethodVisitor.visitFieldInsn(GETSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);
        nextMethodVisitor.visitLdcInsn((int) counterId);
        nextMethodVisitor.visitInsn(AALOAD);
        nextMethodVisitor.visitFieldInsn(GETSTATIC, "net/sourceforge/cobertura/Cobertura",
                "TestClassAndMethodNamesMerged", "Ljava/lang/String;");
        nextMethodVisitor.visitMethodInsn(INVOKEVIRTUAL,
                "net/sourceforge/cobertura/coveragedata/TestUnitInformationHolder", "appendTestUnit",
                "(Ljava/lang/String;)V");
    }

    /**
     * Generates:
     * public static final transient Map __cobertura_counters;
     */
    public void generateCountersField(ClassVisitor cv) {
        FieldVisitor fv = cv.visitField(
                Opcodes.ACC_STATIC | Opcodes.ACC_PUBLIC | Opcodes.ACC_FINAL | Opcodes.ACC_TRANSIENT,
                COBERTURA_COUNTERS_FIELD_NAME, COBERTURA_COUNTERS_FIELD_TYPE, null, null);
        fv.visitEnd();
    }

    /**
     * Generates:
     *   public static void __cobertura_init()
     *   {
     *     if (__cobertura_counters == null)
     *       {
     *         __cobertura_counters = new TestUnitInformationHolder[class.length];
     *       }
     *       TouchCollector.registerClass("mypackage/HelloWorld");
     *   }
     */
    public void generateCINITmethod(MethodVisitor mv, String className, int counters_cnt) {
        mv.visitFieldInsn(Opcodes.GETSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);
        Label l1 = new Label();
        mv.visitJumpInsn(Opcodes.IFNONNULL, l1);
        mv.visitLdcInsn(counters_cnt);
        mv.visitTypeInsn(Opcodes.ANEWARRAY, Type.getInternalName(TestUnitInformationHolder.class));
        mv.visitFieldInsn(Opcodes.PUTSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);

        mv.visitInsn(ICONST_0);
        mv.visitVarInsn(ISTORE, 1);
        Label l11 = new Label();
        mv.visitLabel(l11);
        Label l2 = new Label();
        mv.visitJumpInsn(GOTO, l2);
        Label l3 = new Label();
        mv.visitLabel(l3);
        mv.visitLineNumber(24, l3);
        mv.visitFrame(Opcodes.F_APPEND, 1, new Object[] { Opcodes.INTEGER }, 0, null);
        mv.visitFieldInsn(GETSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME, COBERTURA_COUNTERS_FIELD_TYPE);
        mv.visitVarInsn(ILOAD, 1);
        mv.visitTypeInsn(NEW, "net/sourceforge/cobertura/coveragedata/TestUnitInformationHolder");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "net/sourceforge/cobertura/coveragedata/TestUnitInformationHolder",
                "<init>", "()V");
        mv.visitInsn(AASTORE);
        Label l4 = new Label();
        mv.visitLabel(l4);
        mv.visitLineNumber(23, l4);
        mv.visitIincInsn(1, 1);
        mv.visitLabel(l2);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitVarInsn(ILOAD, 1);
        mv.visitFieldInsn(GETSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME, COBERTURA_COUNTERS_FIELD_TYPE);
        mv.visitInsn(ARRAYLENGTH);
        mv.visitJumpInsn(IF_ICMPLT, l3);

        mv.visitLabel(l1);

        generateRegisterClass(mv, className);
    }

    /**
     * Generates:
     *   public static TestUnitInformationHolder[] __cobertura_get_and_reset_counters()
     *   {
     *     TestUnitInformationHolder[] local = __cobertura_counters;
     *     __cobertura_counters = new TestUnitInformationHolder[__cobertura_counters.length];
     *     return local;
     *   }
     */
    public void generateCoberturaGetAndResetCountersMethod(ClassVisitor cv, String className) {
        MethodVisitor mv = cv.visitMethod(Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC,
                COBERTURA_GET_AND_RESET_COUNTERS_METHOD_NAME, "()" + COBERTURA_COUNTERS_FIELD_TYPE, null, null);
        mv.visitCode();
        /*cobertura_counters.*/
        mv.visitFieldInsn(Opcodes.GETSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);
        mv.visitVarInsn(Opcodes.ASTORE, 0);
        /*cobertura_counters.*/
        mv.visitFieldInsn(Opcodes.GETSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);
        mv.visitInsn(Opcodes.ARRAYLENGTH);

        mv.visitTypeInsn(Opcodes.ANEWARRAY, Type.getInternalName(TestUnitInformationHolder.class));
        mv.visitFieldInsn(Opcodes.PUTSTATIC, className, COBERTURA_COUNTERS_FIELD_NAME,
                COBERTURA_COUNTERS_FIELD_TYPE);
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitInsn(Opcodes.ARETURN);
        mv.visitMaxs(0, 0);//will be recalculated by writer
        mv.visitEnd();
    }
}