RFR: 8026144: Missing mkdir in Images.gmk

[Erik Joelsson]

On 2013-10-10 03:02, David Holmes wrote:
> On 9/10/2013 11:30 PM, Erik Joelsson wrote:
>> I just hit this race when building in jprt. Adding the standard mkdir -p
>> lines should fix it.
>>
>> https://bugs.openjdk.java.net/browse/JDK-8026144
>>
>> http://cr.openjdk.java.net/~erikj/8026144/webrev.jdk.01/
>
> Hmmm. Isn't the real problem that there is a missing dependency on the 
> prior unzipping target (that already does the mkdir). To be pedantic I 
> suppose all three targets should have a dependency on a "prepare" 
> target that does the mkdir.
>
> Adding mkdir to all of them does avoid the problem though.
>
Of those options, I would say a separate rule for the directory would be 
more correct. There is no need to depend on the actual unzipping. It 
would also be complicated by the unzipping rule being a pattern rule, 
making it trickier to follow the dependency chain when reading the code.

It's a matter of design choice I suppose. It's slightly more efficient 
to declare a rule for the directory alone that does the mkdir. At least 
on cygwin where execs are expensive. There are instances of this design 
in the build, but in most places we use the $(install-file) or similar 
macros in the recipe that does mkdir -p, just because it's simpler, 
especially for generated rules. In this case I opted for the smaller 
change and more common pattern.

/Erik