RFR: 8273471: Add foldmultilines to UL for stdout/err [v4]

[Ioi Lam]

On Thu, 9 Sep 2021 23:11:49 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

> > If you run with the following command-line:
> > ```
> > java -Xlog:exceptions:::foldmultilines=true -Xlog:cds:::foldmultilines=false
> > ```
> > 
> > 
> >     
> >       
> >     
> > 
> >       
> >     
> > 
> >     
> >   
> > Does it give a warning, or does it change foldmultilines of stdout to false?
> 
> I think it should give a warning and should keep first option (`foldmultilines=true`). It is same behavior with JDK 16.
> In following case, `filecount` for test.log set to `1` - it is first option.
> 
> ```
> $ java  -Xlog:logging=info -Xlog:os=warning:file=test.log::filecount=1 -Xlog:exceptions=info:file=test.log::filecount=2 --version
> [0.000s][warning][logging] Output options for existing outputs are ignored.
> 
>   (snip)
> 
> [0.010s][info   ][logging] Log output configuration:
> [0.010s][info   ][logging]  #0: stdout all=warning,logging=info uptime,level,tags
> [0.010s][info   ][logging]  #1: stderr all=off uptime,level,tags
> [0.010s][info   ][logging]  #2: file=test.log all=off,os=warning,exceptions=info uptime,level,tags filecount=1,filesize=20480K
> ```
> 
> We need to improve this message of course as you said, but I want to work for it in another issue because the behavior in this PR is same with log file output.

Sorry, I wasn't clear. I am not asking about file output. I am asking about stdout output.


java -Xlog:exceptions:stdout::foldmultilines=true -Xlog:cds:stdout::foldmultilines=false


I think this should give the same type of warning as you would get when the output is a file. I.e., the second `foldmultilines=false` should be ignored. However, I think your current implementation will accept the second `foldmultilines=false` and cause stdout to be printed without folded multilines.

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PR: https://git.openjdk.java.net/jdk/pull/5407