[m-rev.] for review: fix silent failure of making .int file

[Zoltan Somogyi]

2021-12-17 12:26 GMT+11:00 "Julien Fischer" <jfischer at opturion.com>:
>>   Instead of generating error_specs that are conditional on
>>   --warn-unused-imports being OFF, generate them condition on
> 
> s/condition/condtional/
> 
> That's fine otherwise.

Thanks for both reviews.

I think this diff brings up a followup issue, which is: what should we do
with warnings that the compiler generates while making interface files?
At the moment, we print them, and --halt-at-warn turns them into errors
that cause the creation of the .int file to fail, but I see at least two alternatives
that would give programmers more freedom to choose *when* they fix
the warnings.

1 When making interface files, we could simply filter out error_specs
   with severity_warning the same way that this diff filters out error_specs
   that don't print anything.

2. When making interface files, we could decide whether to treat warnings
   as errors not based on the value of --halt-at-warn, but based on the value
   of a new option, maybe called --interface-halt-at-warn, which could be
   set independently. With this option, warnings could still be printed
   at interface generation time, but would not prevent programmers
   prioritizing fixing issues in other modules first.

I myself would prefer 2 over both 1 and the status quo. Any other opinions?

Zoltan.