RFR: 8273072: Avoid using += in configure [v2]

[Magnus Ihse Bursie]

On Fri, 27 Aug 2021 13:22:31 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Magnus Ihse Bursie has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix code review comments
>
> I wouldn't have considered the m4 files as "shell scripts" and I'm surprised that the same operator in makefiles adds extra spaces - that seems unintuitive. But using the expanded format is fine.
> 
> Thanks,
> David

@dholmes-ora The configure script is mostly shell code, with some m4 abstractions in it. (Autoconf calls this mongrel language for "m4sh". I'd rate it a 1 out of 5. Recommendation: stay away. ;-))

Makefiles, otoh, is a proper language, albeit badly designed. I'm actually a bit unsure if a construct like `FOO+=BAR` with no spaces would add a space (I still believe so, since make is so word-oriented), but we always use `FOO += BAR`. (Which is not possible in shells since that would not count as a variable assignment but a command execution...)

-------------

PR: https://git.openjdk.java.net/jdk/pull/5276