error when reading class file with unknown newer jdk version

[Cherry-picked f430e44][modified]

Author: WojciechMazur

compiler/src/dotty/tools/dotc/core/classfile/ClassfileConstants.scala

@@ -11,6 +11,7 @@ object ClassfileConstants {
  inline val JAVA_MINOR_VERSION = 3
 
  inline val JAVA8_MAJOR_VERSION = 52
+ inline val JAVA_LATEST_MAJOR_VERSION = 65
 
  /** (see http://java.sun.com/docs/books/jvms/second_edition/jvms-clarify.html)
  *

compiler/src/dotty/tools/dotc/core/classfile/ClassfileParser.scala

@@ -25,6 +25,8 @@ import io.{AbstractFile, ZipArchive}
 import scala.util.control.NonFatal
 
 object ClassfileParser {
+ import ClassfileConstants.*
+
  /** Marker trait for unpicklers that can be embedded in classfiles. */
  trait Embedded
 
@@ -50,6 +52,23 @@ object ClassfileParser {
  mapOver(tp)
  }
  }
+
+ private[classfile] def parseHeader(classfile: AbstractFile)(using in: DataReader): Unit = {
+ val magic = in.nextInt
+ if (magic != JAVA_MAGIC)
+ throw new IOException(s"class file '${classfile}' has wrong magic number 0x${toHexString(magic)}, should be 0x${toHexString(JAVA_MAGIC)}")
+ val minorVersion = in.nextChar.toInt
+ val majorVersion = in.nextChar.toInt
+ if ((majorVersion < JAVA_MAJOR_VERSION) ||
+ ((majorVersion == JAVA_MAJOR_VERSION) &&
+ (minorVersion < JAVA_MINOR_VERSION)))
+ throw new IOException(
+ s"class file '${classfile}' has unknown version $majorVersion.$minorVersion, should be at least $JAVA_MAJOR_VERSION.$JAVA_MINOR_VERSION")
+ if majorVersion > JAVA_LATEST_MAJOR_VERSION then
+ throw new IOException(
+ s"class file '${classfile}' has unknown version $majorVersion.$minorVersion, and was compiled by a newer JDK than supported by this Scala version, please update to a newer Scala version.")
+ }
+
 }
 
 class ClassfileParser(
@@ -82,7 +101,7 @@ class ClassfileParser(
  def run()(using Context): Option[Embedded] = try ctx.base.reusableDataReader.withInstance { reader =>
  implicit val reader2 = reader.reset(classfile)
  report.debuglog("[class] >> " + classRoot.fullName)
- parseHeader()
+ parseHeader(classfile)
  this.pool = new ConstantPool
  val res = parseClass()
  this.pool = null
@@ -96,19 +115,6 @@ class ClassfileParser(
  |${Option(e.getMessage).getOrElse("")}""")
  }
 
- private def parseHeader()(using in: DataReader): Unit = {
- val magic = in.nextInt
- if (magic != JAVA_MAGIC)
- throw new IOException(s"class file '${classfile}' has wrong magic number 0x${toHexString(magic)}, should be 0x${toHexString(JAVA_MAGIC)}")
- val minorVersion = in.nextChar.toInt
- val majorVersion = in.nextChar.toInt
- if ((majorVersion < JAVA_MAJOR_VERSION) ||
- ((majorVersion == JAVA_MAJOR_VERSION) &&
- (minorVersion < JAVA_MINOR_VERSION)))
- throw new IOException(
- s"class file '${classfile}' has unknown version $majorVersion.$minorVersion, should be at least $JAVA_MAJOR_VERSION.$JAVA_MINOR_VERSION")
- }
-
  /** Return the class symbol of the given name. */
  def classNameToSymbol(name: Name)(using Context): Symbol =
  val nameStr = name.toString