Add filter for Kotlin "unsafe" cast operator (#761)

2 files changed, 73 insertions, 1 deletions

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 03c85d7d..f6a7a1df 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
@@ -34,7 +34,8 @@ public final class Filters implements IFilter {
 			new StringSwitchJavacFilter(), new StringSwitchEcjFilter(),
 			new EnumEmptyConstructorFilter(), new AnnotationGeneratedFilter(),
 			new KotlinGeneratedFilter(), new KotlinLateinitFilter(),
-			new KotlinWhenFilter(), new KotlinWhenStringFilter());
+			new KotlinWhenFilter(), new KotlinWhenStringFilter(),
+			new KotlinUnsafeCastOperatorFilter());
 
 	private final IFilter[] filters;
 
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinUnsafeCastOperatorFilter.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinUnsafeCastOperatorFilter.java
new file mode 100644
index 00000000..b65cac27
--- /dev/null
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinUnsafeCastOperatorFilter.java
@@ -0,0 +1,71 @@
+/*******************************************************************************
+ * 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 org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.JumpInsnNode;
+import org.objectweb.asm.tree.LdcInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+
+/**
+ * Filters branch in bytecode that Kotlin compiler generates for "unsafe" cast
+ * operator.
+ */
+public final class KotlinUnsafeCastOperatorFilter implements IFilter {
+
+	private static final String KOTLIN_TYPE_CAST_EXCEPTION = "kotlin/TypeCastException";
+
+	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) {
+
+			if (Opcodes.IFNONNULL != start.getOpcode()) {
+				return;
+			}
+			cursor = start;
+
+			nextIsNew(KOTLIN_TYPE_CAST_EXCEPTION);
+			nextIs(Opcodes.DUP);
+			nextIs(Opcodes.LDC);
+			if (cursor == null) {
+				return;
+			}
+			final LdcInsnNode ldc = (LdcInsnNode) cursor;
+			if (!(ldc.cst instanceof String && ((String) ldc.cst)
+					.startsWith("null cannot be cast to non-null type"))) {
+				return;
+			}
+			nextIsInvokeSuper(KOTLIN_TYPE_CAST_EXCEPTION,
+					"(Ljava/lang/String;)V");
+			nextIs(Opcodes.ATHROW);
+			if (cursor == null) {
+				return;
+			}
+			if (cursor.getNext() != ((JumpInsnNode) start).label) {
+				return;
+			}
+
+			output.ignore(start, cursor);
+		}
+	}
+
+}