ocaml-index

Ocaml-index is a tool that indexes values from CMT files. Its current purpose is to provide project-wide occurrences for OCaml codebases. The tool iterate on given cmt's occurrences list (cmt_ident_occurrences) and determines the definition of every value found in it. It then write an index to disk where values corresponding to the same definition are grouped together. The tool can also take multiple input files, index them and merge the results into a single index.

Usage

Process cmt files and merge indexes

ocaml-index aggregate [-o _outputfile] _cmtfile ... _indexfile ... [-I dir] ... [--no-cmt-load-path]

• Input cmt files are indexed and merged into the final output
• Input index files are directly merged into the output
• If no input files is provided an empty index is created
• The default output file name is project.ocaml-index

Load path:

Identifying definitions while processing cmt files may require loading any of the cmt files of every transitive dependency of the compilation unit. By default the cmt_load_path of the first input cmt file will be used to search for these other units. One can add more paths to the load path using the -I option. Usage of the cmt's loadpath can be disabled using the --no-cmt-load-path option.

Paths:

By default, the paths stored in the cmt's locations are relative to the directory where the compiler was called. for build systems that do not always call the compiler from the same root folder it might be useful to rewrite these paths.

Using the --root <path> option stores the given path in the output file. Additionally, the --rewrite-root option will prepend root to all paths in indexed location.

[Note: this feature is not used in the reference Dune rules, it might evolve in the future if needed]

Querying indexes

The tool does not provide actual queries but one can dump an entire index:

ocaml-index dump _indexfile ...

Or only print the number of definitions it stores:

ocaml-index stats _indexfile ...

$ ocaml-index stats _build/default/src/dune_rules/.dune_rules.objs/cctx.ocaml-index
Index ".../cctx.ocaml-index" contains:
- 28083 definitions
- 86850 locations
- 0 approximated definitions
- 0 compilation units shapes