RFR: 7903478: JMH: Use different padding names for B1 and B3 classes to avoid "hiding fields with same name" warnings

[Aleksey Shipilev]

On Mon, 29 May 2023 06:12:49 GMT, Vladimir Sitnikov <vsitnikov at openjdk.org> wrote:

> see https://bugs.openjdk.org/browse/CODETOOLS-7903478
> 
> 
> Sample output:
> 
> 
> public final class CustomTest_bench_jmhTest {
> 
>     byte p000, p001, p002, p003, p004, p005, p006, p007, p008, p009, p010, p011, p012, p013, p014, p015;
>     byte p016, p017, p018, p019, p020, p021, p022, p023, p024, p025, p026, p027, p028, p029, p030, p031;
>     byte p032, p033, p034, p035, p036, p037, p038, p039, p040, p041, p042, p043, p044, p045, p046, p047;
>     byte p048, p049, p050, p051, p052, p053, p054, p055, p056, p057, p058, p059, p060, p061, p062, p063;
> ..
>     byte p224, p225, p226, p227, p228, p229, p230, p231, p232, p233, p234, p235, p236, p237, p238, p239;
>     byte p240, p241, p242, p243, p244, p245, p246, p247, p248, p249, p250, p251, p252, p253, p254, p255;
>     int startRndMask;
>     BenchmarkParams benchmarkParams;
> 
> 
> 
> public class CustomTest_jmhType_B1 extends org.openjdk.jmh.it.annsteal.CustomTest {
>     byte b1_000, b1_001, b1_002, b1_003, b1_004, b1_005, b1_006, b1_007, b1_008, b1_009, b1_010, b1_011, b1_012, b1_013, b1_014, b1_015;
>     byte b1_016, b1_017, b1_018, b1_019, b1_020, b1_021, b1_022, b1_023, b1_024, b1_025, b1_026, b1_027, b1_028, b1_029, b1_030, b1_031;
> ...
>     byte b1_224, b1_225, b1_226, b1_227, b1_228, b1_229, b1_230, b1_231, b1_232, b1_233, b1_234, b1_235, b1_236, b1_237, b1_238, b1_239;
>     byte b1_240, b1_241, b1_242, b1_243, b1_244, b1_245, b1_246, b1_247, b1_248, b1_249, b1_250, b1_251, b1_252, b1_253, b1_254, b1_255;
> }
> 
> 
> 
> public class CustomTest_jmhType_B3 extends CustomTest_jmhType_B2 {
>     byte b3_000, b3_001, b3_002, b3_003, b3_004, b3_005, b3_006, b3_007, b3_008, b3_009, b3_010, b3_011, b3_012, b3_013, b3_014, b3_015;
>     byte b3_016, b3_017, b3_018, b3_019, b3_020, b3_021, b3_022, b3_023, b3_024, b3_025, b3_026, b3_027, b3_028, b3_029, b3_030, b3_031;
> ...
>     byte b3_224, b3_225, b3_226, b3_227, b3_228, b3_229, b3_230, b3_231, b3_232, b3_233, b3_234, b3_235, b3_236, b3_237, b3_238, b3_239;
>     byte b3_240, b3_241, b3_242, b3_243, b3_244, b3_245, b3_246, b3_247, b3_248, b3_249, b3_250, b3_251, b3_252, b3_253, b3_254, b3_255;
> }

Looks like a right direction to take. Comments below. Also, please go to https://github.com/vlsi/jmh/actions and enable the GHA testing.

jmh-core/src/main/java/org/openjdk/jmh/generators/core/Paddings.java line 42:

> 40:             throw new IllegalArgumentException("prefix must not be empty");
> 41:         }
> 42:         StringJoiner sj = new StringJoiner("");

What's the point of rewriting this to `StringJoiner`? `StringBuilder` optimizations would be nice to have, if available in the JIT.

jmh-core/src/main/java/org/openjdk/jmh/generators/core/StateObjectHandler.java line 970:

> 968:                 pw.println("public class " + so.type + "_B1 extends " + so.userType + " {");
> 969:                 // The prefix for padding should be different from the one used in _B3 to avoid
> 970:                 // "hiding field of the same name in superclass" warning

You don't need these comments, the issue history has enough breadcrumbs about this.

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

PR Review: https://git.openjdk.org/jmh/pull/104#pullrequestreview-1449789769
PR Review Comment: https://git.openjdk.org/jmh/pull/104#discussion_r1209509897
PR Review Comment: https://git.openjdk.org/jmh/pull/104#discussion_r1209510170