Integrated: 8257848: -XX:CompileCommand=blackhole, * should be diagnostic

[Aleksey Shipilev]

On Mon, 7 Dec 2020 18:48:28 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> This follows up on retroactive CSR review comments (JDK-8257827). As the result of discussion, it is decided to demote the "blackhole" compile command to diagnostic. Examples:
> 
> $ build/linux-x86_64-server-release/images/jdk/bin/java -Xcomp -XX:CompileCommand=quiet -XX:CompileCommand=blackhole,java/lang/Object.toString
> OpenJDK 64-Bit Server VM warning: Blackhole compile option is diagnostic and must be enabled via -XX:+UnlockDiagnosticVMOptions
> 
> $ build/linux-x86_64-server-release/images/jdk/bin/java -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:CompileCommand=quiet -XX:CompileCommand=blackhole,java/lang/Object.toString
> OpenJDK 64-Bit Server VM warning: Blackhole compile option only works for methods with void type: java.lang.Object.toString()Ljava/lang/String;
> 
> New test verifies the locking/unlocking of the command.
> 
> Testing:
>  - [x] ad-hoc `compiler/blackhole` test
>  - [x] validation runs with JMH
>  - [x] runs in `tier1` (needs #1654 to be merged)

This pull request has now been integrated.

Changeset: 35e81536
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/35e81536
Stats:     322 lines in 4 files changed: 218 ins; 101 del; 3 mod

8257848: -XX:CompileCommand=blackhole,* should be diagnostic

Reviewed-by: vlivanov

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PR: https://git.openjdk.java.net/jdk/pull/1674