Upgrade ASM to 7.1 (#851)

6 files changed, 97 insertions, 20 deletions

diff --git a/org.jacoco.build/pom.xml b/org.jacoco.build/pom.xml
index 0ac0077d..afb76b1e 100644
--- a/org.jacoco.build/pom.xml
+++ b/org.jacoco.build/pom.xml
@@ -138,7 +138,7 @@
     <argLine>${jvm.args}</argLine>
 
     <!-- Dependencies versions -->
-    <asm.version>7.0</asm.version>
+    <asm.version>7.1</asm.version>
     <ant.version>1.7.1</ant.version>
     <args4j.version>2.0.28</args4j.version>
     <junit.version>4.8.2</junit.version>
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/instr/InstrSupportTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/instr/InstrSupportTest.java
index f9cf3c13..d679cdbb 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/instr/InstrSupportTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/instr/InstrSupportTest.java
@@ -71,10 +71,42 @@ public class InstrSupportTest {
 	}
 
 	@Test
-	public void getVersionMajor_should_return_major_version_number() {
-		final byte[] bytes = new byte[] { (byte) 0xCA, (byte) 0xFE, (byte) 0xBA,
-				(byte) 0xBE, /* minor */ 0x00, 0x03, /* major */ 0x00, 0x2D };
-		assertEquals(45, InstrSupport.getVersionMajor(bytes));
+	public void getMajorVersion_should_read_unsigned_two_bytes_at_offset_6() {
+		final byte[] bytes = new byte[] { //
+				(byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE, // magic
+				(byte) 0xFF, (byte) 0xFF, // minor_version
+				(byte) 0x80, (byte) 0x12 // major_version
+		};
+
+		assertEquals(32786, InstrSupport.getMajorVersion(bytes));
+	}
+
+	@Test
+	public void setMajorVersion_should_write_unsigned_two_bytes_at_offset_6() {
+		final byte[] bytes = new byte[8];
+
+		InstrSupport.setMajorVersion(32786, bytes);
+
+		assertArrayEquals(
+				new byte[] { (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, // magic
+						(byte) 0x00, (byte) 0x00, // minor_version
+						(byte) 0x80, (byte) 0x12 // major_version
+				}, bytes);
+	}
+
+	@Test
+	public void getMajorVersion_should_read_major_version_from_ClassReader_at_offset_relative_to_constant_pool() {
+		final byte[] bytes = new byte[] { //
+				(byte) 0xFF, // before class bytes
+				(byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE, // magic
+				0x00, 0x03, // minor_version
+				(byte) 0x80, 0x12, // major_version
+				0x00, 0x02, // constant_pool_count
+				0x01, 0x00, 0x00 // constant_pool
+		};
+
+		assertEquals(32786,
+				InstrSupport.getMajorVersion(new ClassReader(bytes, 1, -1)));
 	}
 
 	@Test
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 79748c10..561b09cb 100644
--- a/org.jacoco.core/src/org/jacoco/core/instr/Instrumenter.java
+++ b/org.jacoco.core/src/org/jacoco/core/instr/Instrumenter.java
@@ -81,7 +81,7 @@ public class Instrumenter {
 		};
 		final IProbeArrayStrategy strategy = ProbeArrayStrategyFactory
 				.createFor(classId, reader, accessorGenerator);
-		final int version = InstrSupport.getVersionMajor(source);
+		final int version = InstrSupport.getMajorVersion(reader);
 		final ClassVisitor visitor = new ClassProbesAdapter(
 				new ClassInstrumenter(strategy, writer),
 				InstrSupport.needsFrames(version));
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 99e00270..1e438958 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
@@ -158,18 +158,52 @@ public final class InstrSupport {
 	 */
 	static final int CLINIT_ACC = Opcodes.ACC_SYNTHETIC | Opcodes.ACC_STATIC;
 
-	private static final int MAJOR_VERSION_INDEX = 6;
+	/**
+	 * Gets major version number from given bytes of class (unsigned two bytes
+	 * at offset 6).
+	 *
+	 * @param b
+	 *            bytes of class
+	 * @return major version of bytecode
+	 * @see <a href=
+	 *      "https://docs.oracle.com/javase/specs/jvms/se11/html/jvms-4.html#jvms-4.1">Java
+	 *      Virtual Machine Specification §4 The class File Format</a>
+	 * @see #setMajorVersion(int, byte[])
+	 * @see #getMajorVersion(ClassReader)
+	 */
+	public static int getMajorVersion(final byte[] b) {
+		return ((b[6] & 0xFF) << 8) | (b[7] & 0xFF);
+	}
 
 	/**
-	 * Gets major of bytecode version number from given bytes of class.
+	 * Sets major version number in given bytes of class (unsigned two bytes at
+	 * offset 6).
 	 *
+	 * @param majorVersion
+	 *            major version of bytecode to set
 	 * @param b
 	 *            bytes of class
-	 * @return version of bytecode
+	 * @see #getMajorVersion(byte[])
+	 */
+	public static void setMajorVersion(final int majorVersion, final byte[] b) {
+		b[6] = (byte) (majorVersion >>> 8);
+		b[7] = (byte) majorVersion;
+	}
+
+	/**
+	 * Gets major version number from given {@link ClassReader}.
+	 *
+	 * @param reader
+	 *            reader to get information about the class
+	 * @return major version of bytecode
+	 * @see ClassReader#ClassReader(byte[], int, int)
+	 * @see #getMajorVersion(byte[])
 	 */
-	public static int getVersionMajor(final byte[] b) {
-		return (short) (((b[MAJOR_VERSION_INDEX] & 0xFF) << 8)
-				| (b[MAJOR_VERSION_INDEX + 1] & 0xFF));
+	public static int getMajorVersion(final ClassReader reader) {
+		// relative to the beginning of constant pool because ASM provides API
+		// to construct ClassReader which reads from the middle of array
+		final int firstConstantPoolEntryOffset = reader.getItem(1) - 1;
+		return reader.readUnsignedShort(firstConstantPoolEntryOffset - 4);
 	}
 
 	/**
@@ -237,15 +271,13 @@ public final class InstrSupport {
 	 * @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 int originalVersion = getMajorVersion(b);
+		if (originalVersion == Opcodes.V12 + 1) {
+			// temporarily downgrade version to bypass check in ASM
+			setMajorVersion(Opcodes.V12, b);
 		}
 		final ClassReader classReader = new ClassReader(b);
-		System.arraycopy(originalVersion, 0, b, 4, originalVersion.length);
+		setMajorVersion(originalVersion, b);
 		return classReader;
 	}
 
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/instr/ProbeArrayStrategyFactory.java b/org.jacoco.core/src/org/jacoco/core/internal/instr/ProbeArrayStrategyFactory.java
index 72c8dd68..d5756b7f 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/instr/ProbeArrayStrategyFactory.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/instr/ProbeArrayStrategyFactory.java
@@ -43,7 +43,7 @@ public final class ProbeArrayStrategyFactory {
 			final IExecutionDataAccessorGenerator accessorGenerator) {
 
 		final String className = reader.getClassName();
-		final int version = InstrSupport.getVersionMajor(reader.b);
+		final int version = InstrSupport.getMajorVersion(reader);
 
 		if (isInterfaceOrModule(reader)) {
 			final ProbeCounter counter = getProbeCounter(reader);
diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index 15250c84..71faf94f 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -30,6 +30,13 @@
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/849">#849</a>).</li>
 </ul>
 
+<h3>Fixed bugs</h3>
+<ul>
+  <li>Fixed incorrect update of frames caused by bug in ASM library in case of
+      arrays with more than 7 dimensions
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/839">#839</a>).</li>
+</ul>
+
 <h3>API Changes</h3>
 <ul>
     <li>Methods <code>Instrumenter.instrument(org.objectweb.asm.ClassReader)</code>
@@ -38,6 +45,12 @@
         (GitHub <a href="https://github.com/jacoco/jacoco/issues/850">#850</a>).</li>
 </ul>
 
+<h3>Non-functional Changes</h3>
+<ul>
+  <li>JaCoCo now depends on ASM 7.1
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/851">#851</a>).</li>
+</ul>
+
 <h2>Release 0.8.3 (2019/01/23)</h2>
 
 <h3>New Features</h3>