RFR: JDK-8211724: Change mkdir -p to MakeDir macro where possible

[Erik Joelsson]

Hello,

On 2018-10-07 02:52, Magnus Ihse Bursie wrote:
> One problem with this is that you're replacing this pattern
> rm -r $DIR
> mkdir -p $DIR
> with this:
> mkdir -p $DIR
> rm -r $DIR/*
>
> However, they are not equivalent. :( The latter will not remove any hidden dot-files.
Not equivalent, but I very much doubt it matters in any of the changed 
locations.

On the other hand, using the MakeDir macro in a recipe that is already 
deleting the target directory is pointless since the directory will 
never be reused anyway. That construct can also never work if there are 
concurrent mkdir lines for the same directory, so we know these are safe 
already. For these reasons, I reverted those changes. The rm -r followed 
by mkdir -p pattern is ok as it is.
> I recommend that you create a new macro like MakeAndCleanDir, which does this, and that it either keeps the old behavior of always removing the dir recursively and then re-create it, or that your create it conditionally like now but fix so rm also handles dot-files. Or that it checks if any files are present by $(wildcard) and only calls rm if needed. This is likely most efficient, but care must be taken to be sure to check for dot files, but not for the . or .. dirs.
This seems a bit excessive to me and unlikely to provide any real benefit.

New webrev: http://cr.openjdk.java.net/~erikj/8211724/webrev.02/

/Erik
> /Magnus
>
>> 5 okt. 2018 kl. 23:31 skrev Erik Joelsson <erik.joelsson at oracle.com>:
>>
>> As a followup to JDK-8211677, here is an attempt at fixing most other instances of $(MKDIR) -p to instead of the MakeDir or MakeTargetDir macros. Since fixing the previous bug, we have hit the race in other recipes as well so this is really needed.
>>
>> There are some situations where the macro would not apply, so those have been skipped. I'm also pretty sure that those are race free. See bug comment for details.
>>
>> In addition to this I evaluated the AC_PROG_MKDIR_P macro. It didn't quite work out for us however. The fallback method if it cannot find a suitable mkdir binary is to use the build-aux/install.sh script. Our problem is that we have not included this script in our source (just a fake empty file) and to include it now would require a lot of legal work. What I've done instead is to simply add gmkdir first in the list of programs to look for when searching for mkdir. On Solaris, this is the program the macro found (and internally we have that installed on Solaris), so this will at least fix the immediate problem we are currently facing.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8211724
>>
>> Webrev: http://cr.openjdk.java.net/~erikj/8211724/webrev.01/index.html
>>
>> /Erik
>>