RFR(S): 8198608: Improvements to command-line flags printing

Schmidt, Lutz lutz.schmidt at sap.com
Sat Mar 3 17:04:54 UTC 2018


Hi David, 

I guess I have to apologize! There must be something wrong with my test coverage.

As of now, I don't have an idea why a flag value would not be printed correctly.

I will look into this, and the ResourceMark issue as well,  asap.

Regards,
Lutz

On 03.03.18, 10:30, "David Holmes" <david.holmes at oracle.com> wrote:

    There are also test failures:
    
    compiler/jvmci/compilerToVM/GetFlagValueTest
    
    java.lang.RuntimeException: Unexpected line in -XX:+PrintFlagsFinal 
    output: bool BootstrapJVMCI = false {JVMCI experimental}{default}: 
    expected true, was false
    
    Can you please ensure you're checked for all tests that use PrintFlags 
    or PrintFlagsFinal and verify that they run okay in both product and 
    fastdebug. I see the failures on multiple platforms but linux-x64 is one 
    so you should be able to test that one easily.
    
    Thanks,
    David
    
    On 3/03/2018 2:44 PM, David Holmes wrote:
    > I'll sponsor this.
    > 
    > I don't see Goetz's email to the list but will take it as per your 
    > response.
    > 
    > Cheers,
    > David
    > 
    > On 3/03/2018 1:04 AM, Schmidt, Lutz wrote:
    >> Hi David,
    >>
    >> it would be great if you could sponsor this change. I was able to 
    >> successfully test on darwinintel64, linuxs390x, linuxppc64, and 
    >> linuxx86_64. Our AIX systems are not playing nice with me at the 
    >> moment (no issues with the change, just general misbehavior).
    >>
    >> I have modified line 551 according to your suggestion (and line 519 as 
    >> well). Webrev updated in-place.
    >>
    >> So let's hope for a second review over the weekend.
    >>
    >> Regards,
    >> Lutz
    >>
    >>
    >> On 02.03.18, 02:19, "David Holmes" <david.holmes at oracle.com> wrote:
    >>
    >>      On 1/03/2018 11:25 PM, Schmidt, Lutz wrote:
    >>      > Hi David,
    >>      > thank you for looking at this. You are right, the comment is a 
    >> useless leftover -> removed in if and else branch.
    >>      Looks fine. Just need a second reviewer. Do you need a sponsor to 
    >> test
    >>      on additional platforms? Otherwise what platforms have you tested?
    >>      > With the "\n" handling, I believe we are on the safe side. If a 
    >> newline character is detected in the parameter string, it is replaced 
    >> by a st->cr() call. That call does the expected on any platform, I 
    >> would hope. Flag::print_as_flag() (not in the scope of the change) 
    >> uses a similar handling.
    >>      >
    >>      > The newlines are contained in string literals in C code (e.g. 
    >> default values for parameters) or stem from ccstrlist concatenations. 
    >> That is all under VM control. So I do not see a risk here. You can try 
    >> yourself on any platform with the -XX:DisableIntrinsic=test1 parameter 
    >> multiple times.
    >>      >
    >>      > If a user manages to specify a parameter string with platform 
    >> (windows) specific line terminators and hopes for correct (\n-like) 
    >> handling, he or she will be disappointed. I would assume the 
    >> PrintFlags formatting isn't the only place that's impacted.
    >>      Sorry I mistakenly thought you had modified the newline handling, 
    >> when
    >>      you hadn't. If there is an issue it would be preexisting. I was
    >>      wondering how you would get a multi-line ccstr value. If you 
    >> entered it
    >>      on the command-line e.g:
    >>      java -XX:OnError="Line 1
    >>      Line2"
    >>      then I would expect to find the platform line separator within the
    >>      string. In testing this with the existing PrintFlagsFinal Linux 
    >> does:
    >>      ccstrlist OnError                                  = Line 1
    >>             OnError                             += Line 2
    >>                     {product} {command line}
    >>      but testing on Windows is a problem. The regular cmd shell can't 
    >> take
    >>      multi-line arguments. If you use the ^ escape trick it actually 
    >> strips
    >>      the newline and passes the arg as one line. So I guess the issue is
    >>      somewhat moot. :)
    >>      One further nit:
    >>        551           st->print("%s", "+=");
    >>      should just be:
    >>        551           st->print("+=");
    >>      Thanks,
    >>      David
    >>      > I have updated the webrev in-place with the comments removed.
    >>      >
    >>      > Thanks again, Lutz
    >>      >
    >>      >
    >>      > On 28.02.18, 23:26, "David Holmes" <david.holmes at oracle.com> 
    >> wrote:
    >>      >
    >>      >      Hi Lutz,
    >>      >
    >>      >      On 24/02/2018 2:48 AM, Schmidt, Lutz wrote:
    >>      >      > Dear all,
    >>      >      >
    >>      >      > may I please request reviews for this small enhancement:
    >>      >      >
    >>      >      > Bug:     https://bugs.openjdk.java.net/browse/JDK-8198608
    >>      >      > Webrev:  
    >> http://cr.openjdk.java.net/~lucy/webrevs/8198608.00/
    >>      >      >
    >>      >      > The code in Flag::print_on() so far wasn’t very easy to 
    >> understand. Changing the layout of what was printed required some deep 
    >> thinking. I hope that, with my changes, future modifications will be 
    >> easier.
    >>      >      >
    >>      >      > The before/after output of -XX:+PrintFlagsFinal is 
    >> identical, except for those argument names which are longer than 
    >> expected. In that case, the new version prints one space less, which 
    >> is by intention.
    >>      >
    >>      >      This all seems okay - and easier to modify further if needed.
    >>      >
    >>      >      Two minor comments:
    >>      >
    >>      >        576     // Flag::print_on(...) redesign (!print_ranges)
    >>      >
    >>      >      Isn't this the print_ranges case? But in any case not sure 
    >> a comment
    >>      >      with "redesign" in it is that meaningful given you can't 
    >> see the old design.
    >>      >
    >>      >      Does the ccstr newline handling work on all platforms (ie 
    >> Windows) - I'm
    >>      >      never sure when it suffices to check for '\n' and when we 
    >> have to check
    >>      >      for the platform specific line terminators.
    >>      >
    >>      >      Thanks,
    >>      >      David
    >>      >
    >>      >      > Thank you!
    >>      >      > Lutz
    >>      >      >
    >>      >      >
    >>      >      >
    >>      >      > Dr. Lutz Schmidt | SAP JVM | PI  SAP CP Core | T: +49 
    >> (6227) 7-42834
    >>      >      >
    >>      >
    >>      >
    >>
    



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