RFR: JDK-8248158 Configure fails with autoconf not found even though it's installed

[Magnus Ihse Bursie]

On 2020-07-01 12:05, Galder Zamarreno wrote:
> Using `which` to check whether commands exist can result in confusing
> errors when `which` itself is not installed in the system. This is the case
> with `autoconf`, where if `autoconf` is present but `which` isn't, the
> build system says that `autoconf` is missing, when in reality it is `which`
> which is missing. The fix switches autoconf uses of `which` for `type -p`
> instead, which is a Bash built-in command.
>
> I've tested the fix with a fedora docker container that had `autoconf`
> installed but `which`. When using `type -p` it correctly detects `autoconf`
> installed and eventually fails saying that `which` is not installed, which
> is the expected behaviour.
>
> `which` is still in use in make/autoconf/util_windows.m4. A possible future
> improvement would be to see if `which` use there could be replaced as well.
> Eventually, when no `which` uses remain, the presence check for `which`
> could be removed.
I agree that we should replace "which" with "type -p" everywhere. The 
best way to do this is probably to replace the value of $WHICH with 
"type -p". It's a bash built-in, so we can count on its presence. If you 
want to fix that as part of this bug, I'm ok with it, otherwise we 
should open a new bug to track this. I think there is also one or two 
instances of "command" recently added as (better, but not as good as 
"type -p") replacements for which.

/Magnus
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8248158
> WebRev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8248158/01/webrev/
>
> Galder