RFR(S): 8154251: ANSI-C Quoting bug in hotspot.m4 during configure on SLES 10 and 11

[Erik Joelsson]

Looks good to me. I tried the patch locally and it seems to be working. 
I will sponsor it as soon as the appropriate hotspot repo is open again.

/Erik

On 2016-04-14 17:55, Volker Simonis wrote:
> Hi,
>
> can somebody please review this small hotspot build fix for SLES 10 an 11:
>
> http://cr.openjdk.java.net/~simonis/webrevs/2016/8154251/
> https://bugs.openjdk.java.net/browse/JDK-8154251
>
> I've encountered a strange configure problem with the new hotspot build
> system on SLES 10 and 11:
> ...
> checking which variants of the JVM to build... server
> configure: Unknown variant(s) specified: server
> configure: error: The available JVM variants are: server client minimal
> core zero zeroshark custom
> configure exiting with result code 1
> ...
>
> The error seems nonsense since 'server' is a valid variant.
> For debugging purpose I ran "bash -vx configure ..." and this revealed:
> ...
> $GREP -Fvx "${VALID_JVM_VARIANTS// /$'\n'}" <<< "${JVM_VARIANTS// /$'\n'}"
> ++++ /usr/bin/grep -Fvx
> 'server$\nclient$\nminimal$\ncore$\nzero$\nzeroshark$\ncustom'
> +++ INVALID_VARIANTS=server
> ...
> The expected result would be:
> ...
> $GREP -Fvx "${VALID_JVM_VARIANTS// /$'\n'}" <<< "${JVM_VARIANTS// /$'\n'}"
> ++++ /bin/grep -Fvx 'server
> client
> minimal
> core
> zero
> zeroshark
> custom'
> +++ INVALID_VARIANTS=
> ...
> Apparently, the ANSI-C Quoting (see
> http://www.gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.html#ANSI_002dC-Quoting)
> for "${VALID_JVM_VARIANTS// /$'\n'}" went wrong. Instead of replacing
> Spaces by newlines, it wrongly replaced Spaces by $\n literally instead.
>
> I tried to find the specific problem without success. There exist several
> bugs about ANSI-C Quoting in bash however. I could reproduce the problem on
> SLES 10.3 with the builtin bash 3.1.17 and a self-built bash 4.3.0 and also
> on a SLES 11.3 with the builtin bash 3.2.51. It worked on a newer SLES 12.1
> with bash 4.2.47. I couldn't reproduce the problem on RHEL, Ubuntu and
> Fedora.
>
> Thank you and best regards,
> Volker