[13] RFR (S): 8217404: --with-jvm-features doesn't work when multiple features are explicitly disabled

[Igor Ignatyev]

Hi Vladimir,

overall your fix looks reasonable, but w/ it we can get unintentionally disabled features (b/c grep doesn't do full word match). although this problem wasn't really introduced by your fix, I think it's be better to fix it as a part of your patch. I see two possible solutions:
 -  add "-w" to grep, but I am not sure if "-w" is supported by all grep implementations
 - use $XARGS instead of $ECHO when we get DISABLE_X. in this case you will need to revert your changes in 'if test ...' lines

Thanks,
-- Igor

> On Jan 18, 2019, at 3:33 PM, Vladimir Ivanov <vladimir.x.ivanov at oracle.com> wrote:
> 
> http://cr.openjdk.java.net/~vlivanov/8217404/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8217404
> 
> --with-jvm-features doesn't work properly when multiple features are explicitly disabled:
> 
> $ bash configure --with-jvm-features="-aot -jvmci -graal"
> ...
> checking if jvmci module jdk.internal.vm.ci should be built... yes
> checking if graal module jdk.internal.vm.compiler should be built... yes
> checking if aot should be enabled... yes
> ...
> 
> The problem in the following code:
> 
>  DISABLE_AOT=`$ECHO $DISABLED_JVM_FEATURES | $GREP aot`
>  if test "x$DISABLE_AOT" = "xaot"; then
>    ENABLE_AOT="false"
>  fi
> 
> Since DISABLED_JVM_FEATURES ("aot jvmci graal") contains the list of explicitly disabled features, grep over it returns the whole list when there's a match. The subsequent check fails because there's no exact match, though DISABLE_AOT contains "aot" .
> 
> Proposed fix is to check there's no match instead.
> 
> After the fix it works as expected:
> 
> $ bash configure --with-jvm-features="-aot -jvmci -graal"
> ...
> checking if jvmci module jdk.internal.vm.ci should be built... no, forced
> checking if graal module jdk.internal.vm.compiler should be built... no, forced
> checking if aot should be enabled... no, forced
> ...
> 
> (The fix doesn't address the case when one feature has a name which is a proper substring of another feature, but there are no such cases at the moment.)
> 
> Best regards,
> Vladimir Ivanov