RFR: 8252233: Enable debug-image target to support producing a pure debug image package

[Erik Joelsson]

Hello Andrew,

We certainly appreciate contributions, but this patch as it currently 
looks does not fit well with our current build system model. I'm however 
not against adding a target for your usecase.

On a high level, just as Severin pointed out, the term "debug" is used 
for the type configuration we are building (release vs debug). For debug 
information we have instead chosen the term "symbols", so the target 
should rather be called symbols-image. Now I realize we already have 
that target, for something slightly different. I introduced that a long 
time ago for gcov symbols, with the intention of eventually move the 
main debug symbols into it too, but that never happened. I think we can 
just make that change now and let the symbols-image be what you are 
asking for (in addition to the gcov files if those are enabled). This 
will be one step in the direction of a bigger overhaul of the images 
that I want to do anyway.

On a lower level, in Main.gmk, all targets should be declared as calls 
to the macro SetupTarget and in the correct section of the file. In this 
case it would be around line 418 where the current symbols-image is 
declared.

The new file DebugImage.gmk contains a lot of duplication of logic 
already implemented in Images.gmk, which can quite easily be extended to 
cover your usecase.

So all that said, this is how I would suggest to solve it:

http://cr.openjdk.java.net/~erikj/8252233/webrev.01/index.html

With this change, building the symbols image is part of the top level 
product-images target (but separate from the more specific jdk-image 
target). In Bundles.gmk, building the jdk bundles tar.gz gets slightly 
simpler as the files can be found directly in the symbols image.

I still need to test this properly on all platforms.

/Erik

On 2020-08-27 08:55, Andrew Leonard wrote:
> Hi,
> Please may I request a sponsor and review for this build enhancement to
> provide a pure debug "image", for those developers that want to accompany
> a straight jdk image with a debug-image when needed:
>      https://bugs.openjdk.java.net/browse/JDK-8252233
>      webrev: http://cr.openjdk.java.net/~aleonard/8252233/webrev.00/
> We have been providing this as part of the openj9 builds at AdoptOpenJDK
> for a while now, and would like to contribute it upstream to openjdk.
>
> Thanks
> Andrew
>
> Andrew Leonard
> Java Runtimes Development
> IBM Hursley
> IBM United Kingdom Ltd
> internet email: andrew_m_leonard at uk.ibm.com
>
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