[RFC] Replace Java with Go in default languages

[Jeff Law]

On 11/12/13 01:27, Eric Botcazou wrote:
>>  From what I can see, bootstrapping with Ada is slower than bootstapping
>> with Java, by around 15%.  Again this is on one of my slower boxes, but
>> the results clearly show building Ada & its runtime takes a considerable
>> amount of time:
>>
>> default languages:    67 minutes
>> default - java:       51 minutes
>> default - java + go:  56 minutes
>> default - java + ada: 77 minutes
>>
>> [...]
>>
>> Hard to justify switching from Java to Ada given those results if one of
>> the key goals is to reduce waiting time.
Not sure what happened yesterday with the 77 minute timing.

Across 10 runs we came in right at 70 minutes with the usual ~20 second 
variance.  So it's slightly slower than the default languages right now. 
  That doesn't help the cycle time for developers which was the major 
point for me.

Given the problems Ian outlined around adding Go to the default 
languages and the build time issues with using Ada instead of Java, I'm 
unsure how best to proceed.

I'm starting to wonder if we just remove Java from the default languages 
during stage1, but add it back when we leave stage1.

Similarly I think we should add Go  to the default languages when we 
leave stage1.

As for Ada, I'm wondering if we should add it into the default 
languages, but not require it for the bootstrap/regression test cycle 
during stage1, but require it as we leave stage1.  Thus, if a developer 
has Ada installed, it'll build & test by default.

And, yes I'm aware of the wonderful irony that I'm debugging a bootstrap 
problem with Ada related to my recent work :-)

Thoughts on the updated proposal?


jeff