Add filter for bytecode that ECJ generates for String in switch (#735)

4 files changed, 152 insertions, 5 deletions

diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
index ba862adc..82b97466 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
@@ -173,6 +173,13 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		}
 	}
 
+	private final Map<AbstractInsnNode, Set<AbstractInsnNode>> replacements = new HashMap<AbstractInsnNode, Set<AbstractInsnNode>>();
+
+	public void replaceBranches(final AbstractInsnNode source,
+			final Set<AbstractInsnNode> newTargets) {
+		replacements.put(source, newTargets);
+	}
+
 	@Override
 	public void visitLabel(final Label label) {
 		currentLabel.add(label);
@@ -362,6 +369,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		for (final CoveredProbe p : coveredProbes) {
 			p.instruction.setCovered(p.branch);
 		}
+
 		// Merge:
 		for (final Instruction i : instructions) {
 			final AbstractInsnNode m = i.getNode();
@@ -371,6 +379,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 				nodeToInstruction.get(r).merge(i);
 			}
 		}
+
 		// Report result:
 		coverage.ensureCapacity(firstLine, lastLine);
 		for (final Instruction i : instructions) {
@@ -378,8 +387,23 @@ public class MethodAnalyzer extends MethodProbesVisitor
 				continue;
 			}
 
-			final int total = i.getBranches();
-			final int covered = i.getCoveredBranches();
+			final int total;
+			final int covered;
+			final Set<AbstractInsnNode> r = replacements.get(i.getNode());
+			if (r != null) {
+				int cb = 0;
+				for (AbstractInsnNode b : r) {
+					if (nodeToInstruction.get(b).getCoveredBranches() > 0) {
+						cb++;
+					}
+				}
+				total = r.size();
+				covered = cb;
+			} else {
+				total = i.getBranches();
+				covered = i.getCoveredBranches();
+			}
+
 			final ICounter instrCounter = covered == 0 ? CounterImpl.COUNTER_1_0
 					: CounterImpl.COUNTER_0_1;
 			final ICounter branchCounter = total > 1
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java
index b235cfb8..bdb0854b 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java
@@ -31,9 +31,10 @@ public final class Filters implements IFilter {
 			new TryWithResourcesJavac11Filter(),
 			new TryWithResourcesJavacFilter(), new TryWithResourcesEcjFilter(),
 			new FinallyFilter(), new PrivateEmptyNoArgConstructorFilter(),
-			new StringSwitchJavacFilter(), new EnumEmptyConstructorFilter(),
-			new AnnotationGeneratedFilter(), new KotlinGeneratedFilter(),
-			new KotlinLateinitFilter(), new KotlinWhenSealedFilter());
+			new StringSwitchJavacFilter(), new StringSwitchEcjFilter(),
+			new EnumEmptyConstructorFilter(), new AnnotationGeneratedFilter(),
+			new KotlinGeneratedFilter(), new KotlinLateinitFilter(),
+			new KotlinWhenSealedFilter());
 
 	private final IFilter[] filters;
 
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java
index 4ca9b814..bbcbf00e 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java
@@ -11,6 +11,8 @@
  *******************************************************************************/
 package org.jacoco.core.internal.analysis.filter;
 
+import java.util.Set;
+
 import org.objectweb.asm.tree.AbstractInsnNode;
 
 /**
@@ -41,4 +43,16 @@ public interface IFilterOutput {
 	 */
 	void merge(AbstractInsnNode i1, AbstractInsnNode i2);
 
+	/**
+	 * Marks instruction whose outgoing branches should be replaced during
+	 * computation of coverage.
+	 *
+	 * @param source
+	 *            instruction which branches should be replaced
+	 * @param newTargets
+	 *            new targets of branches
+	 */
+	void replaceBranches(AbstractInsnNode source,
+			Set<AbstractInsnNode> newTargets);
+
 }
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilter.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilter.java
new file mode 100644
index 00000000..cbd2a216
--- /dev/null
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilter.java
@@ -0,0 +1,108 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2018 Mountainminds GmbH & Co. KG and Contributors
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * 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;
+
+/**
+ * Filters code that is generated by ECJ for a <code>switch</code> statement
+ * with a <code>String</code>.
+ */
+public final class StringSwitchEcjFilter implements IFilter {
+
+	public void filter(final MethodNode methodNode,
+			final IFilterContext context, final IFilterOutput output) {
+		final Matcher matcher = new Matcher();
+		for (AbstractInsnNode i = methodNode.instructions
+				.getFirst(); i != null; i = i.getNext()) {
+			matcher.match(i, output);
+		}
+	}
+
+	private static class Matcher extends AbstractMatcher {
+		public void match(final AbstractInsnNode start,
+				final IFilterOutput output) {
+
+			cursor = start;
+
+			nextIsVar(Opcodes.ASTORE, "s");
+			nextIsInvokeVirtual("java/lang/String", "hashCode");
+			nextIsSwitch();
+			if (cursor == null) {
+				return;
+			}
+
+			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();
+			}
+
+			final Set<AbstractInsnNode> replacements = new HashSet<AbstractInsnNode>();
+			replacements.add(instructionAfterLabel(defaultLabel));
+
+			for (int i = 0; i < hashCodes; i++) {
+				while (true) {
+					nextIsVar(Opcodes.ALOAD, "s");
+					nextIs(Opcodes.LDC);
+					nextIsInvokeVirtual("java/lang/String", "equals");
+					// jump to case
+					nextIs(Opcodes.IFNE);
+					if (cursor == null) {
+						return;
+					}
+
+					replacements.add(instructionAfterLabel(
+							((JumpInsnNode) cursor).label));
+
+					if (cursor.getNext().getOpcode() == Opcodes.GOTO) {
+						// end of comparisons for same hashCode
+						// jump to default
+						nextIs(Opcodes.GOTO);
+						break;
+					}
+				}
+			}
+
+			output.ignore(s.getNext(), cursor);
+			output.replaceBranches(s, replacements);
+		}
+	}
+
+	private static AbstractInsnNode instructionAfterLabel(
+			final LabelNode label) {
+		AbstractInsnNode i = label.getNext();
+		while (i.getType() == AbstractInsnNode.FRAME
+				|| i.getType() == AbstractInsnNode.LABEL
+				|| i.getType() == AbstractInsnNode.LINE) {
+			i = i.getNext();
+		}
+		return i;
+	}
+
+}