Add experimental support for Java 13 class files (#835)

5 files changed, 28 insertions, 3 deletions

diff --git a/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java b/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java
index 8b927459..97aa44f1 100644
--- a/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java
+++ b/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java
@@ -30,6 +30,7 @@ import org.jacoco.core.internal.analysis.ClassCoverageImpl;
 import org.jacoco.core.internal.analysis.StringPool;
 import org.jacoco.core.internal.data.CRC64;
 import org.jacoco.core.internal.flow.ClassProbesAdapter;
+import org.jacoco.core.internal.instr.InstrSupport;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.Opcodes;
@@ -112,7 +113,7 @@ public class Analyzer {
 
 	private void analyzeClass(final byte[] source) {
 		final long classId = CRC64.classId(source);
-		final ClassReader reader = new ClassReader(source);
+		final ClassReader reader = InstrSupport.classReaderFor(source);
 		if ((reader.getAccess() & Opcodes.ACC_SYNTHETIC) != 0) {
 			return;
 		}
diff --git a/org.jacoco.core/src/org/jacoco/core/instr/Instrumenter.java b/org.jacoco.core/src/org/jacoco/core/instr/Instrumenter.java
index 201d75ee..89f14019 100644
--- a/org.jacoco.core/src/org/jacoco/core/instr/Instrumenter.java
+++ b/org.jacoco.core/src/org/jacoco/core/instr/Instrumenter.java
@@ -83,7 +83,7 @@ public class Instrumenter {
 
 	private byte[] instrument(final byte[] source) {
 		final long classId = CRC64.classId(source);
-		final ClassReader reader = new ClassReader(source);
+		final ClassReader reader = InstrSupport.classReaderFor(source);
 		final ClassWriter writer = new ClassWriter(reader, 0) {
 			@Override
 			protected String getCommonSuperClass(final String type1,
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/ContentTypeDetector.java b/org.jacoco.core/src/org/jacoco/core/internal/ContentTypeDetector.java
index 1d7617ee..74574ecc 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/ContentTypeDetector.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/ContentTypeDetector.java
@@ -88,6 +88,8 @@ public class ContentTypeDetector {
 			case Opcodes.V11 | Opcodes.V_PREVIEW:
 			case Opcodes.V12:
 			case Opcodes.V12 | Opcodes.V_PREVIEW:
+			case (Opcodes.V12 + 1):
+			case (Opcodes.V12 + 1) | Opcodes.V_PREVIEW:
 				return CLASSFILE;
 			}
 		}
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/instr/InstrSupport.java b/org.jacoco.core/src/org/jacoco/core/internal/instr/InstrSupport.java
index ce4bcbee..99e00270 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/instr/InstrSupport.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/instr/InstrSupport.java
@@ -13,6 +13,7 @@ package org.jacoco.core.internal.instr;
 
 import static java.lang.String.format;
 
+import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 
@@ -227,4 +228,25 @@ public final class InstrSupport {
 		}
 	}
 
+	/**
+	 * Creates a {@link ClassReader} instance for given bytes of class even if
+	 * its version not yet supported by ASM.
+	 *
+	 * @param b
+	 *            bytes of class
+	 * @return {@link ClassReader}
+	 */
+	public static ClassReader classReaderFor(final byte[] b) {
+		final byte[] originalVersion = new byte[] { b[4], b[5], b[6], b[7] };
+		if (getVersionMajor(b) == Opcodes.V12 + 1) {
+			b[4] = (byte) (Opcodes.V12 >>> 24);
+			b[5] = (byte) (Opcodes.V12 >>> 16);
+			b[6] = (byte) (Opcodes.V12 >>> 8);
+			b[7] = (byte) Opcodes.V12;
+		}
+		final ClassReader classReader = new ClassReader(b);
+		System.arraycopy(originalVersion, 0, b, 4, originalVersion.length);
+		return classReader;
+	}
+
 }
diff --git a/org.jacoco.core/src/org/jacoco/core/runtime/ModifiedSystemClassRuntime.java b/org.jacoco.core/src/org/jacoco/core/runtime/ModifiedSystemClassRuntime.java
index a18f7299..5f2cc497 100644
--- a/org.jacoco.core/src/org/jacoco/core/runtime/ModifiedSystemClassRuntime.java
+++ b/org.jacoco.core/src/org/jacoco/core/runtime/ModifiedSystemClassRuntime.java
@@ -153,7 +153,7 @@ public class ModifiedSystemClassRuntime extends AbstractRuntime {
 	 */
 	public static byte[] instrument(final byte[] source,
 			final String accessFieldName) {
-		final ClassReader reader = new ClassReader(source);
+		final ClassReader reader = InstrSupport.classReaderFor(source);
 		final ClassWriter writer = new ClassWriter(reader, 0);
 		reader.accept(new ClassVisitor(InstrSupport.ASM_API_VERSION, writer) {