RFR: JDK-8170632 Stop modifying VERSION_OPT for adhoc builds on reconfigure

[David Holmes]

On 2/12/2016 8:39 AM, Magnus Ihse Bursie wrote:
> Our current default is to create a version-opt string on the format
> '<timestamp>.<username>.<base dir name>' during configure.
>
> The problem with this is that each time the configure script has change,
> a reconfigure is triggered. This will create a new version-opt, and
> hence a new version string. This in turn will trigger a rebuild of
> hotspot and java.base, and that in turn rebuilds the whole world.

Surely after a reconfigure you _have_ to rebuild the world? It even 
warns you to do a clean after a reconfigure.

David
-----

> It does not have to be like that. In fact, storing the time stamp of the
> last configure, rather than the time stamp of the last build is rather
> silly anyhow.
>
> In a perfect world we could just update the version-opt string and have
> this resulting in an extremely short rebuild time. Unfortunately, we do
> not live in a perfect world, and here it makes more sense to drop the
> timestamp.
>
> Note that this only affects adhoc (developer) builds.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8170632
>
> Patch inline:
> diff --git a/common/autoconf/jdk-version.m4
> b/common/autoconf/jdk-version.m4
> --- a/common/autoconf/jdk-version.m4
> +++ b/common/autoconf/jdk-version.m4
> @@ -160,11 +160,10 @@
>      fi
>    else
>      if test "x$NO_DEFAULT_VERSION_PARTS" != xtrue; then
> -      # Default is to calculate a string like this
> <timestamp>.<username>.<base dir name>
> -      timestamp=`$DATE '+%Y-%m-%d-%H%M%S'`
> +      # Default is to calculate a string like this
> 'adhoc.<username>.<base dir name>'
>        # Outer [ ] to quote m4.
>        [ basedirname=`$BASENAME "$TOPDIR" | $TR -d -c
> '[a-z][A-Z][0-9].-'` ]
> -      VERSION_OPT="$timestamp.$USERNAME.$basedirname"
> +      VERSION_OPT="adhoc.$USERNAME.$basedirname"
>      fi
>    fi
>
> /Magnus