RFR [XXS]: 8242000: clean up list of environment variables printed in hs_err file

[Baesken, Matthias]

Hi David ,

I think  "JAVA_COMPILER" is no longer needed,
 (see a remark here that it was used to configure the JIT compiler  https://www.ibm.com/support/knowledgecenter/SSGU8G_12.1.0/com.ibm.sqlr.doc/ids_sqr_280.htm 
 but I cannot  find this any more in the current jdk/jdk codebase).

Regarding JRE_HOME - I find  still some references in the source code, but not many .
Could it be that some installers / tools outside the JDK still set/use it ?

jdk/src/hotspot/share/jfr/dcmd/jfrDcmds.cpp
345 _settings("settings", "Settings file(s), e.g. profile or default. See JRE_HOME/lib/jfr", "STRING SET", false),

jdk/src/hotspot/share/utilities/vmError.cpp
83 "JAVA_HOME", "JRE_HOME", "JAVA_TOOL_OPTIONS", "_JAVA_OPTIONS", "CLASSPATH",

/openjdk-jdk/src/java.base/share/man/java.1
1813 \f[CB]JRE_HOME/lib/jfr\f[R].

So I would suggest to remove JAVA_COMPILER.  Maybe JRE_HOME too (but then also the other 2 references).


Best regards, Matthias



-----Original Message-----
From: David Holmes <david.holmes at oracle.com> 
Sent: Donnerstag, 2. April 2020 11:41
To: Baesken, Matthias <matthias.baesken at sap.com>; 'hotspot-dev at openjdk.java.net' <hotspot-dev at openjdk.java.net>
Subject: Re: RFR [XXS]: 8242000: clean up list of environment variables printed in hs_err file

Hi Matthias,

On 2/04/2020 4:55 pm, Baesken, Matthias wrote:
> Hello, please review this very small cleanup change.
> 
> When discussing the environment variables printed in the hs_err file, we 
> found that
> some cleanup should be done , David  pointed out  :
> 
>>> I think we can dispense with LD_ASSUME_KERNEL, and _JAVA_SR_SIGNUM is
>>> used on Linux, BSD and AIX. :) Not for this change of course.
> 
> Bug/webrev :
> 
> https://bugs.openjdk.java.net/browse/JDK-8242000
> 
> http://cr.openjdk.java.net/~mbaesken/webrevs/8242000.0/

That fixes the two examples I already found but the intent was to do a 
more thorough examination of all the variables to see if they are still 
relevant e.g is JRE_HOME still meaningful? What does JAVA_COMPILER do? 
The intent is to report env vars that can affect the execution of the JVM.

Cheers,
David

> Thanks, Matthias
>