Code / Formatting guidelines checker

[AHaumer]

In a discussion the idea came up to have tool independent checker for coding and formatting.
I know that some parts of such a thing exist in some tools, but it would be nice to have a tool independent solution (like the regression check!).
Let the tool run through all models of a library, getting a list of things to improve, like:
parameter description missing, icon color is wrong, name in icon layer has wrong size and color
and many more - fortunately we have guidelines in the UsersGuide.

[atrosinenko]

I have recently implemented an initial support of Modelica in PMD static code analyzer. For now, it is experimental (but already merged into master) and has only demo rules, but:

• PMD has language-agnostic "XPath rule" built-in, so you can write some XPath queries that mark matched nodes as violations - without any Java coding at all, just external XMLs with rules

  • one of these demo rules is

    //ClassSpecifier/*[SimpleName[1]/@Image != SimpleName[last()]/@Image]
    

    it basically checks for model Name end OtherName; mistakes

• PMD Modelica language module already has some more-or-less MLS-aligned flattening process to resolve type references
  • the other demo rule tries to find suspicious class name shadowing
  • requires Java coding to utilize
• PMD has Copy-Paste Detector module that can find large-enough copied parts
  • in some sense, it is even harder to review: if someone sends a bad pull request, it would probably be rejected or improved by maintainers, but if some other PR has parts of code copied from other places of the same repo (already reviewed and good quality!), then maintainer need to know all codebase at once to notice copy-paste
  • it seems, it already found a 180-line copy-paste in MSL

It is still not published as part of the released Binary Distribution (the next release is planned at the end of January), so manual build of master branch is required. Also, it is still experimental, so some API still may change.

Last but not least: sometimes Modelica compilers crash with Internal compiler error or something like this. There exist many different tools to minimize source code that crash the compiler. I have implemented yet another as a tool for PMD that should support any "fully-featured" (that is, not CPD-only) PMD language (including Modelica). Its maintainers placed it to separate repo pmd/pmd-scm as another experimental feature.

PS: On "coding and formattig": generally, PMD cannot check formatting, since it works with AST. On the other hand, it can trivially check some assertions about coding style such as "every package name starts with p letter".