[User Experience] Request to Suppress or Merge Overwhelming `timescale` Errors

[JacyCui]

---

Including a timescale directive in one module causes diagnostics to be reported for all the other modules in the workspace that do not declare it, flooding the Problems panel with an overwhelming number of duplicate diagnostics.

A much much more user-friendly handling could be suppressing repeated timescale diagnostics after the first report, or merging them into a single summarized workspace/project diagnostic.

Additionally, this situation likely fits better as a warning rather than an error.

[hongjr03]

Thanks for reporting!

Slang documents this behavior in its --timescale option:

If this option is not set, there is no default and an error will be issued if not all elements have a time scale specified.

This follows the SystemVerilog LRM rules around timeunit, timeprecision, and timescale (IEEE 1800-2023, section 3.14.2.3, Page 60):

It shall be an error if some design elements have a time unit and precision specified and others do not.

So I think the diagnostic itself is valid.

However, I agree that flooding the problem panel with bunch of repeated diagnostics is quite noisy. For the UX design I need to furthure discuss with @roife .

For now, a well configured vizsla_config.toml may partially solve this. Also, it can be suppressed or downgraded via vizsla.diagnostics.slang.rules:

{
  "vizsla.diagnostics.slang.rules": [
    { "selector": "code:13:22", "severity": "ignore" }
  ]
}

Or downgrade it to a warning:

{
  "vizsla.diagnostics.slang.rules": [
    { "selector": "code:13:22", "severity": "warning" }
  ]
}

The code can be found in the diagnostic message, like:

This feature will be well documented in the future.

[hongjr03]

Reopen this for tracking for documentation description.