RFR: 8300829: Make CtwRunner available as an independent tool

[Xin Liu]

On Wed, 5 Apr 2023 04:46:21 GMT, Joshua Cao <duke at openjdk.org> wrote:

> 1. Create an independent jar file with CtwRunner as the main class to make it easier to run
> 2. Output the class files directly into the destination directory. Currently, CTW expects a `wb.jar`, but the jtreg tests that use CTWRunner has class files outside of a jar.
> 3. Introduce `sun.hotspot.tools.ctwrunner.ctw_extra_args` option to pass extra arguments to CTW. Arguments are comma separated because working with spaces in bash can be kind of awkward, but I'm open to changing this part.
> 
> ### Motivation
> CTWRunner is a wrapper around CTW that will continue compiling beyond failure. It can be useful for testing compilation with certain flags. For example, one could run
> 
> 
> JAVA_OPTIONS="-Dsun.hotspot.tools.ctwrunner.ctw_extra_args=-XX:+StressLCM,-XX:+StressGCM" ./ctwrunner.sh modules:java.base
> 
> 
> To test compiling the java.base module with `-XX:+StressLCM -XX:+StressGCM`. This is advantageous over uses CTW because we can see the full list of crashes for the entire module.

test/hotspot/jtreg/testlibrary/ctw/src/sun/hotspot/tools/ctw/CtwRunner.java line 60:

> 58:      * comma-separated arguments to pass to CTW subprocesses.
> 59:      */
> 60:     public static final String CTW_EXTRA_ARGS

how about you use getProperty("sun.hotspot.tools.ctwrunner.ctw_extra_args", "").
by giving it an empty string as default value, you can take iout if (null != CTW_EXTRA_ARGS) below. 

btw, you may also need to update the year in the copyrights header.

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PR Review Comment: https://git.openjdk.org/jdk/pull/13344#discussion_r1158030134