RFR: 8292914: Drop the counter from lambda class names [v8]

[Mandy Chung]

On Fri, 17 Feb 2023 19:37:59 GMT, David M. Lloyd <duke at openjdk.org> wrote:

>> The class generated for lambda proxies is now defined as a hidden class. This means that the counter, which was used to ensure a unique class name and avoid clashes, is now redundant. In addition to performing redundant work, this also impacts build reproducibility for native image generators which might already have a strategy to cope with hidden classes but cannot cope with indeterminate definition order for lambda proxy classes.
>> 
>> This solves JDK-8292914 by making lambda proxy names always be stable without any configuration needed. This would also replace #10024.
>
> David M. Lloyd has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Many tests have patterns for lambda class names; update them
>  - Update comments and javadoc showin the old pattern

src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java line 370:

> 368:                 if (useImplMethodHandle) {
> 369:                     lookup = caller.defineHiddenClassWithClassData(classBytes, implementation, !disableEagerInitialization,
> 370:                         NESTMATE, STRONG);

nit: formatting - align this line to the first argument `classBytes` in L369.

src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java line 374:

> 372:                     lookup = caller.defineHiddenClass(classBytes, !disableEagerInitialization, NESTMATE, STRONG);
> 373:                 }
> 374:             } catch (Throwable t) {

suggest to use try-finally in writing the file.


            Lookup lookup = null;
            try {
                if (useImplMethodHandle) {
                    lookup = caller.defineHiddenClassWithClassData(classBytes, implementation, !disableEagerInitialization,
                                                                   NESTMATE, STRONG);
                } else {
                    lookup = caller.defineHiddenClass(classBytes, !disableEagerInitialization, NESTMATE, STRONG);
                }
            } finally {
                // If requested, dump out to a file for debugging purposes
                if (dumper != null) {
                    final String name;
                    if (lookup != null) {
                        String definedName = lookup.lookupClass().getName();
                        int suffixIdx = definedName.lastIndexOf('/');
                        assert suffixIdx != -1;
                        name = lambdaClassName + '.' + definedName.substring(suffixIdx + 1);
                    } else {
                        name = lambdaClassName + ".failed-" + counter.incrementAndGet();
                    }
                    doDump(name, classBytes);
                }
            }
            return lookup.lookupClass();

-------------

PR: https://git.openjdk.org/jdk/pull/12579