RFR: 8336856: Optimize String Concat [v11]

[Shaojin Wen]

On Wed, 24 Jul 2024 15:08:50 GMT, Chen Liang <liach at openjdk.org> wrote:

>> If you do not use TRUSTED Lookup, errors will occur when processing records.
>> 
>> You can see this build error https://github.com/wenshao/jdk/actions/runs/10049344961/job/27775952878
>> 
>> TEST: java/lang/reflect/records/RecordReflectionTest.java
>> 
>> 
>> Caused by: java.lang.IllegalAccessException: no such method: java.lang.StringConcatHelper$$StringConcat/0xad1b77c0.concat(R1,R2,R3)String/invokeStatic
>>     at java.base/java.lang.invoke.MemberName.makeAccessException(MemberName.java:906)
>>     at java.base/java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:989)
>>     at java.base/java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:3750)
>>     at java.base/java.lang.invoke.MethodHandles$Lookup.findStatic(MethodHandles.java:2648)
>>     at java.base/java.lang.invoke.StringConcatFactory$SimpleStringBuilderStrategy.generate(StringConcatFactory.java:727)
>>     ... 41 more
>> Caused by: java.lang.LinkageError: bad method type alias: (R1,R2,R3)String not visible from class java.lang.StringConcatHelper$$StringConcat/0xad1b77c0
>>     at java.base/java.lang.invoke.MemberName.ensureTypeVisible(MemberName.java:812)
>>     at java.base/java.lang.invoke.MemberName$Factory.resolve(MemberName.java:961)
>>     at java.base/java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:986)
>>     ... 44 more
>> 
>> 
>> 
>>     record R1() {}
>> 
>>     record R2(int i, int j) {}
>> 
>>     record R3(List<String> ls) {}
>> 
>>    // error
>>     record R4(R1 r1, R2 r2, R3 r3) {}
>> 
>> 
>> This PR also fixes the issue with TRUSTED not working in MemberName.java after using TRUSTED Lookup.
>
> The solution is to call `.erase()` on the input method handle, and call `viewAsType` on the result method handle.

Sorry, I don't understand what you mean. The following code can't solve the above build error


public static CallSite makeConcatWithConstants() {
// line 383
                return new ConstantCallSite(
                        SimpleStringBuilderStrategy.generate(lookup, concatType, constantStrings)
                                .viewAsType(concatType, true));

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PR Review Comment: https://git.openjdk.org/jdk/pull/20273#discussion_r1690626588