RFR: 8357660: [JVMCI] Add Support for Retrieving All Indy BootstrapMethodInvocations directly from the ConstantPool

[Doug Simon]

On Tue, 27 May 2025 20:10:50 GMT, Tom Shull <duke at openjdk.org> wrote:

>> How about `List<BootstrapMethodInvocation> lookupBootstrapMethodInvocations(boolean indy)`? That is, it either gets the indy *or* the condy BSM invocations. I can imagine SVM wanting the latter at some point right?
>> 
>> BTW, I noticed that the javadoc for `ConstantPool.lookupBootstrapMethodInvocation` is somewhat incorrect. Please check and apply these corrections in this PR:
>> 
>> diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/meta/ConstantPool.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/meta/ConstantPool.java
>> index 2273b256f03..3519af4bcbb 100644
>> --- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/meta/ConstantPool.java
>> +++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/meta/ConstantPool.java
>> @@ -199,12 +199,12 @@ interface BootstrapMethodInvocation {
>>       * in the constant pool.
>>       *
>>       * @param index if {@code opcode} is -1,  {@code index} is a constant pool index. Otherwise {@code opcode}
>> -     *              must be {@code Bytecodes.INVOKEDYNAMIC}, and {@code index} must be the operand of that
>> -     *              opcode in the bytecode stream (i.e., a {@code rawIndex}).
>> -     * @param opcode must be {@code Bytecodes.INVOKEDYNAMIC}, or -1 if
>> +     *              must be {@code Bytecodes.INVOKEDYNAMIC} or {@code CONSTANT_Dynamic_info}, and {@code index}
>> +     *              must be the operand of that opcode in the bytecode stream (i.e., a {@code rawIndex}).
>> +     * @param opcode must be {@code Bytecodes.INVOKEDYNAMIC}, {@code CONSTANT_Dynamic_info}, or -1 if
>>       *            {@code index} was not decoded from a bytecode stream
>>       * @return the bootstrap method invocation details or {@code null} if the entry specified by {@code index}
>> -     *         is not a {@code CONSTANT_Dynamic_info} or @{code CONSTANT_InvokeDynamic_info}
>> +     *         is not a {@code CONSTANT_Dynamic_info} or {@code CONSTANT_InvokeDynamic_info}
>>       * @jvms 4.7.23 The {@code BootstrapMethods} Attribute
>>       */
>>      default BootstrapMethodInvocation lookupBootstrapMethodInvocation(int index, int opcode) {
>
> I prototyped the option `List<BootstrapMethodInvocation> lookupBootstrapMethodInvocations(boolean indy)` here: https://github.com/openjdk/jdk/compare/master...teshull:jdk:jvmci_bootstrap_alternative
> 
> As part of this I also prototyped generic BSM resolution / lookup logic
> 
> From the SVM perspective, retrieving condys via this new support isn't a big win. It's easy enough already to walk the ConstantPool. However, for symmetry purposes, it is reasonable to have this method (along with the resolve / lookup). What's your preference: this new version or the original?

I like the symmetry of the new version. Also, I think you can simplify things by replacing use of `flatMap` [here](https://github.com/openjdk/jdk/compare/master...teshull:jdk:jvmci_bootstrap_alternative#diff-b782878562668748c5c59acc2e937f7c24de4529b8a74bd3a4eae83fa0e07846R679) with `filter`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25420#discussion_r2111539245