StringSwitchFilter.java
/*******************************************************************************
* Copyright (c) 2009, 2024 Mountainminds GmbH & Co. KG and Contributors
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* Evgeny Mandrikov - initial API and implementation
*
*******************************************************************************/
package org.jacoco.core.internal.analysis.filter;
import java.util.HashSet;
import java.util.Set;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.LookupSwitchInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.TableSwitchInsnNode;
import org.objectweb.asm.tree.VarInsnNode;
/**
* Filters code that is generated by ECJ for a <code>switch</code> statement
* with a <code>String</code> and by Kotlin compiler 1.5 and above for a
* <code>when</code> expression with a <code>String</code>.
*/
public final class StringSwitchFilter implements IFilter {
public void filter(final MethodNode methodNode,
final IFilterContext context, final IFilterOutput output) {
final Matcher matcher = new Matcher();
for (final AbstractInsnNode i : methodNode.instructions) {
matcher.match(i, output);
}
}
private static class Matcher extends AbstractMatcher {
public void match(final AbstractInsnNode start,
final IFilterOutput output) {
if (start.getOpcode() != /* ECJ */ Opcodes.ASTORE
&& start.getOpcode() != /* Kotlin */ Opcodes.ALOAD) {
return;
}
cursor = start;
nextIsInvoke(Opcodes.INVOKEVIRTUAL, "java/lang/String", "hashCode",
"()I");
nextIsSwitch();
if (cursor == null) {
return;
}
vars.put("s", (VarInsnNode) start);
final AbstractInsnNode s = cursor;
final int hashCodes;
final LabelNode defaultLabel;
if (s.getOpcode() == Opcodes.LOOKUPSWITCH) {
final LookupSwitchInsnNode lookupSwitch = (LookupSwitchInsnNode) cursor;
defaultLabel = lookupSwitch.dflt;
hashCodes = lookupSwitch.labels.size();
} else {
final TableSwitchInsnNode tableSwitch = (TableSwitchInsnNode) cursor;
defaultLabel = tableSwitch.dflt;
hashCodes = tableSwitch.labels.size();
}
if (hashCodes == 0) {
return;
}
final Set<AbstractInsnNode> replacements = new HashSet<AbstractInsnNode>();
replacements.add(skipNonOpcodes(defaultLabel));
for (int i = 0; i < hashCodes; i++) {
while (true) {
nextIsVar(Opcodes.ALOAD, "s");
nextIs(Opcodes.LDC);
nextIsInvoke(Opcodes.INVOKEVIRTUAL, "java/lang/String",
"equals", "(Ljava/lang/Object;)Z");
// jump to case
nextIs(Opcodes.IFNE);
if (cursor == null) {
return;
}
replacements
.add(skipNonOpcodes(((JumpInsnNode) cursor).label));
if (cursor.getNext().getOpcode() == Opcodes.GOTO) {
// end of comparisons for same hashCode
// jump to default
nextIs(Opcodes.GOTO);
break;
} else if (cursor.getNext() == defaultLabel) {
break;
}
}
}
output.ignore(s.getNext(), cursor);
output.replaceBranches(s, replacements);
}
}
}