Include Long/Double size in max param count

Author: som-snytt

src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala

@@ -613,9 +613,20 @@ abstract class BCodeSkelBuilder extends BCodeHelpers {
       for (p <- params) locals.makeLocal(p.symbol)
       // debug assert((params.map(p => locals(p.symbol).tk)) == asmMethodType(methSymbol).getArgumentTypes.toList, "debug")
 
-      if (params.size > MaximumJvmParameters) {
-        // scala/bug#7324
-        reporter.error(methSymbol.pos, s"Platform restriction: a parameter list's length cannot exceed $MaximumJvmParameters.")
+      // scala/bug#7324
+      // https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.3.3
+      // https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.11
+      // https://docs.oracle.com/javase/specs/jvms/se20/html/jvms-4.html#jvms-4.11
+      val paramsLength = params.foldLeft(0) { (sum, p) =>
+        val i = p.symbol.info.typeSymbol match {
+          case definitions.LongClass | definitions.DoubleClass => 2
+          case _ => 1
+        }
+        sum + i
+      }
+      if (paramsLength > MaximumJvmParameters) {
+        val info = if (paramsLength == params.length) "" else " (Long and Double count as 2)"
+        reporter.error(methSymbol.pos, s"Platform restriction: a parameter list's length cannot exceed $MaximumJvmParameters$info.")
         return
       }
 

src/reflect/scala/reflect/internal/util/ScalaClassLoader.scala

@@ -43,7 +43,7 @@ final class RichClassLoader(private val self: JClassLoader) extends AnyVal {
   def tryToInitializeClass[T <: AnyRef](path: String): Option[Class[T]] = tryClass(path, initialize = true)
 
   private def tryClass[T <: AnyRef](path: String, initialize: Boolean): Option[Class[T]] =
-    catching(classOf[ClassNotFoundException], classOf[SecurityException]) opt
+    catching(classOf[ClassFormatError], classOf[ClassNotFoundException], classOf[SecurityException]) opt
       Class.forName(path, initialize, self).asInstanceOf[Class[T]]
 
   /** Create an instance of a class with this classloader */

test/files/neg/t7324.check

@@ -0,0 +1,53 @@
+
+import org.junit.Assert.{assertEquals, assertFalse, assertTrue}
+import scala.reflect.internal.util.ScalaClassLoader
+import scala.tools.partest.StoreReporterDirectTest
+
+object Test extends StoreReporterDirectTest {
+
+  //override def extraSettings: String = "-usejavacp -Xlint"
+
+  def code = classOfArgs(254)
+
+  def show() = {
+    val compiler = newCompiler()
+    assertTrue(compileString(compiler)(code))
+    load()
+    assertFalse(compileString(compiler)(classOfArgs(255)))
+    check()
+    assertTrue(compileString(compiler)(methodOfArgs(254)))
+    load()
+    assertFalse(compileString(compiler)(methodOfArgs(255)))
+    check()
+    assertFalse(compileString(compiler)(methodOfArgs(254, "Long")))
+    check(isLongly = true)
+    assertTrue(compileString(compiler)(methodOfArgs(254/2, "Long")))
+    load()
+    assertFalse(compileString(compiler)(methodOfArgs(254/2 + 1, "Long")))
+    check(isLongly = true)
+    assertFalse(compileString(compiler)(methodOfArgs(254, "Double")))
+    check(isLongly = true)
+    assertTrue(compileString(compiler)(methodOfArgs(254/2, "Double")))
+    load()
+    assertFalse(compileString(compiler)(methodOfArgs(254/2 + 1, "Double")))
+    check(isLongly = true)
+  }
+
+  private def check(isLongly: Boolean = false) = {
+    assertTrue("Expected diagnostics", storeReporter.infos.nonEmpty)
+    val expected =
+      if (isLongly) "Platform restriction: a parameter list's length cannot exceed 254 (Long and Double count as 2)."
+      else "Platform restriction: a parameter list's length cannot exceed 254."
+    storeReporter.infos.foreach(info => assertEquals(expected, info.msg))
+  }
+  private def load() = {
+    val loader = ScalaClassLoader.fromURLs(Seq(testOutput.jfile.toURI.toURL))
+    assertFalse("Expected loadable class B", loader.tryToLoadClass("B").isEmpty)
+  }
+
+  private def classOfArgs(n: Int, t: String = "Int") = s"class B${mkArgs(n, t)}"
+
+  private def methodOfArgs(n: Int, t: String = "Int") = s"class B { def m${mkArgs(n, t)}: Unit = () }"
+
+  private def mkArgs(n: Int, t: String) = 1.to(n).map(i => s"x$i: $t").mkString("(",",",")")
+}