[igt-dev] Scripting language for igt

[Joonas Lahtinen]

Quoting Chris Wilson (2018-08-20 13:11:15)

<SNIP>

> In both cases it was easy to extend the test beyond the original. Joonas
> who is more familiar with the later declarative ECMAScript, says he can
> reduce the boilerplate code even further. (Some of the verbosity is on
> purpose, since these tests are negative tests and so want to need to dig
> beneath the usual layers of convenience api, but still the plan should
> be to autogenerate as much of the ioctl breaking as possible.)
> 
> TLDR; I want to rewrite BAT and use a script interpreter for speed of
> execution, ease of test writing, and for automating test generation. 
> I would like to drop duktape into igt/shell, but the initial code drop
> may be too big to post/review... So I would like to present it as fait
> accompli and then work on the smaller patches to make the magic happen.

We exchanged some further ideas about this, and my suggestions:

Use v8, for the sake of having a large user base (and the modern
language features) and JIT for speed.

The igt shell code only really needs to expose IOCTLs and then maybe
some debugfs derived values. This helps in having a very clearly defined
interface for the tests to the system (you simply can't poke unintended
holes through the meant interface, as you are writing all the testing
code inside the interpreter). On top of which we can add abstractions on
the ECMAScript files themselves for things like spin batches etc.

Regards, Joonas