False alarms for native projects that generate new files

[Zeta611]

Hi, reanalyze currently emits false alarms for native (OCaml) projects that generate new .ml files when built.

This MWE demonstrates this using ocamlyacc and ocamllex. In this example, reanalyze warns about a dead constructor that is actually visited by a generated pareser.

This is because reanalyze tries to find a file lib/parser.ml, while it is only present in the build target directory. For projects using dune, this directory defaults to _build/default/.

[Zeta611]

Here is a pull request #175 that enables users to specify build target directory, though I'm not quite sure if this is a scalable solution. This does work for the MWE I provided.

[cristianoc]

It is already possible to specify paths, inclusions, exclusions from the command line, to look in specific folders and select only certain things. See the CLI arguments.

[Zeta611]

Thank you for the quick response.

I'm a bit confused--is it possible to look inside the build target directory to remove the false warnings I mentioned above? I am unable to do so using the -unsuppress flag by adding the build target directory.

I only get a correct result when I navigate inside _build/default and change the current working directory, but not in the root project directory as guided in the README file; is this an intended behavior?

[LimitEpsilon]

Hi, I was trying out reanalyze with @Zeta611 earlier this day, and I also have some understanding about this issue.

The problem that @Zeta611 is pointing out is not the inability to specify folders to find .cmt files in.

Rather, it is a problem when Sys.file_exists is evaluated in src/FindSourceFile.ml. The path to the source file(.ml or .mli) is a relative path, and therefore is resolved relative to the current working directory.

Thus, when reanalyze is executed in the project root, even if we specify _build/default, for example, the source files are not found. Or is this already covered in the CLI arguments?

[cristianoc]

If I understand correctly. What if you go into _build/default then run the executable from there? Does it have the behaviour you need?

[LimitEpsilon]

Yes, going into _build/default and executing reanalyze works!

[cristianoc]

Is the option provided still useful? I don't mind merging as it's a simple change.

[Zeta611]

Specifying a build target path is more straightforward than having to manually navigate inside the build target directory, so the new option is useful in dune projects IMHO.

[cristianoc]

PR merged.