RFR(m): 8145468 deprecations for java.lang
forax at univ-mlv.fr
Thu Apr 14 13:21:18 UTC 2016
you are not the first one to try to change the integers defined in org.objectweb.asm.Opcodes, those values are compared by ref (not by value) inside ASM.
You're patch will change the behavior of any Interpreters that also use some Integers created by Integer.valueOf() because valueOf may cache the Integer references.
I will add a comment in the ASM trunk for avoid such refactoring in the future.
----- Mail original -----
> De: "Stuart Marks" <stuart.marks at oracle.com>
> À: "core-libs-dev" <core-libs-dev at openjdk.java.net>
> Envoyé: Jeudi 14 Avril 2016 03:50:14
> Objet: RFR(m): 8145468 deprecations for java.lang
> Hi all,
> Please review this first round of deprecation changes for the java.lang
> This changeset includes the following:
> - a set of APIs being newly deprecated
> - a set of already-deprecated APIs that are "upgraded" to forRemoval=true
> - addition of the "since" element to all deprecations
> - cleanup of some of the warnings caused by new deprecations
> The newly deprecated APIs include all of the constructors for the boxed
> primitives. We don't intend to remove these yet, so they don't declare a
> for the forRemoval element, implying the default value of false. The
> constructors being deprecated are as follows:
> The methods being deprecated with forRemoval=true are listed below. All of
> methods have already been deprecated. They are all ill-defined, or they don't
> work, or they don't do anything useful.
> SecurityManager.checkMemberAccess(Class<?>, int)
> Most of the files in the changeset are cleanups. Some of them are simply the
> addition of the "since" element to the @Deprecated annotation, to indicate
> version in which the API became deprecated.
> The rest of the changes are cleanup of warnings that were created by the
> deprecation of the boxed primitive constructors. There are a total of a
> hundred such uses sprinkled around the JDK. I've taken care of a portion of
> them, with the exception of the java.desktop module, which alone has over 100
> uses of boxed primitive constructors. I've disabled deprecation warnings for
> java.desktop module for the time being; these uses can be cleaned up later.
> filed JDK-8154213 to cover this cleanup task.
> For the warnings cleanups I did, I mostly did conversions of the form:
> new Double(dval)
> This is a very safe transformation. It changes the behavior only in the cases
> where the code relies on getting a new instance of the box object instead of
> that might come out of a cache. I didn't see any such code (and I should hope
> there's no such code in the JDK!).
> I applied autoboxing only sparingly, in the cases where it was an obviously
> thing to do, or where nearby code already uses autoboxing. Autoboxing
> generates a call to the appropriate valueOf() method, so the bytecode would
> the same in most cases. The only difference is clutter in the source code. On
> the other hand, there's some risk in converting to autoboxing, as the
> autoboxed type might end up different from an explicit call to valueOf().
> isn't always obvious, so that's why I mostly avoided autoboxing.
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