SonarSource provides a static code analyzer for XML. Based on our own technology, SonarXML analyzes code and find code smells. As for any product we develop at SonarSource, it was built on the following principles: depth, accuracy and speed.
The SonarXML capability is available in Eclipse for developers (SonarLint) as well as throughout the development chain for automated code review with self-hosted SonarQube or on-line SonarCloud.
SonarXML supports custom rules written in XPath.