On Sat, 22 Jun 2024 15:55:28 GMT, Oussama Louati <[email protected]> wrote:
>> An indify tool in j.l.i tests (also in vmTestBase) convert some source-code
>> private static methods with MT_ MH_, and INDY_ prefixes into MethodHandle,
>> MethodType, and CallSite constants.
>> ### Purpose of Indify
>>
>> - **Transformation Tool**: `Indify` transforms existing class files to
>> leverage `invokedynamic` and other JSR 292 features. This transformation
>> allows for dynamic method calls.
>>
>> ### Key Functions
>>
>> - **Method Handle and Method Type Constants**:
>> - **MH_x and MT_x Methods**: These methods are used to generate
>> `MethodHandle` and `MethodType` constants. The tool transforms calls to
>> these methods into `CONSTANT_MethodHandle` and `CONSTANT_MethodType` "ldc"
>> (load constant) instructions.
>> - **Invokedynamic Call Sites**:
>> - **INDY_x Methods**: These methods generate `invokedynamic` call sites.
>> Each `INDY_x` method starts with a call to an `MH_x` method, which acts as
>> the bootstrap method. This is followed by an `invokeExact` call.
>> - **Transformation**: The tool transforms pairs of calls (to `INDY_x`
>> followed by `invokeExact`) into `invokedynamic` instructions. This mimics
>> the JVM's handling of `invokedynamic` instructions, creating dynamic call
>> sites that are linked at runtime.
>>
>> It currently uses ad-hoc code to process class files and intends to migrate
>> to ASM; but since we have the Classfile API, we can migrate to Classfile API
>> instead.
>
> Oussama Louati has updated the pull request incrementally with one additional
> commit since the last revision:
>
> remove: removed unnecessary logging
test/jdk/java/lang/invoke/indify/Indify.java line 386:
> 384:
> 385: byte[] transformToBytes(ClassModel classModel) {
> 386: return of().transform(classModel, ClassTransform.ACCEPT_ALL);
What is the purpose of this transformation?
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/18841#discussion_r1652808158
