Summary

Method j.l.c.MethodTypeDesc.dropParameterTypes​ should specify IndexOutOfBoundsException in a case not documented by its specification. The specification must be updated.

Problem

Interface java.lang.constant.MethodTypeDesc extends interface: java.lang.invoke.TypeDescriptor.OfMethod. But there is a mismatch between the specification of method java.lang.invoke.TypeDescriptor.OfMethod::dropParameterTypes and its implementation at java.lang.constant.MethodTypeDescImpl::dropParameterTypes.

The reason for the mismatch is that an unspecified exception is being thrown. Also the specification of method java.lang.constant.MethodTypeDesc::dropParameterTypes differs from that of java.lang.invoke.TypeDescriptor.OfMethod::dropParameterTypes. The one in the subinterface should be in sync with the one in the superinterface, java.lang.invoke.TypeDescriptor.OfMethod.

Solution

Update implementation at java.lang.constant.MethodTypeDescImpl::dropParameterTypes so that it doesn't throw any unspecified exception and sync the specification of java.lang.constant.MethodTypeDesc::dropParameterTypes with that of java.lang.invoke.TypeDescriptor.OfMethod

Specification

diff -r 5d8c5c7bca95 -r 4d3de18055c8 src/java.base/share/classes/java/lang/constant/MethodTypeDesc.java
--- a/src/java.base/share/classes/java/lang/constant/MethodTypeDesc.java        Tue May 14 21:36:09 2019 +0300
+++ b/src/java.base/share/classes/java/lang/constant/MethodTypeDesc.java        Tue May 14 16:22:04 2019 -0400
@@ -141,8 +141,8 @@
      * @param end the index after the last parameter to remove
      * @return a {@linkplain MethodTypeDesc} describing the desired method type
      * @throws IndexOutOfBoundsException if {@code start} is outside the half-open
-     * range {[0, parameterCount)}, or {@code end} is outside the closed range
-     * {@code [0, parameterCount]}
+     * range {@code [0, parameterCount)}, or {@code end} is outside the closed range
+     * {@code [0, parameterCount]}, or if {@code start > end}
      */
     MethodTypeDesc dropParameterTypes(int start, int end);