Hi Peter,
I can see you are openly exploring possibilities to fulfil your use-case. As far as SonarSource products are concerned, I can confirm the following:
-
SonarQube: XML custom rules can only be implemented via XPath (using the rule
Track breaches of an XPath rule) -
SonarLint:
- XML is currently not supported, see discussion here
- SonarLint does not support 3rd-party analyzers (relates to the requirements of delivering in-IDE analysis on-the-fly). Only rules extending APIs from built-in analyzers can eventually be marked compatible with SonarLint (though as you noticed, the XML analyzer does not offer Java extension APIs).