Move ocaml index (#1793)

Moved from voodoos/ocaml-index

.github/workflows/main.yml

@@ -68,7 +68,7 @@ jobs:
       - name: Build and test in release mode (windows)
         if: matrix.os == 'windows-latest'
         run: |
-          opam exec -- dune runtest -p merlin-lib,dot-merlin-reader,merlin
+          opam exec -- dune runtest -p merlin-lib,dot-merlin-reader,ocaml-index,merlin
 
       - name: Build and test in release mode (macos/linux)
         if: matrix.os != 'windows-latest'

.github/workflows/nix.yml

@@ -34,4 +34,4 @@ jobs:
       uses: cachix/install-nix-action@v27
       with:
         nix_path: nixpkgs=channel:nixos-unstable
-    - run: nix develop -c dune build @check @runtest -p merlin-lib,dot-merlin-reader,merlin
+    - run: nix develop -c dune build @check @runtest -p merlin-lib,dot-merlin-reader,ocaml-index,merlin

merlin-lib.opam

@@ -11,7 +11,7 @@ build: [
 ]
 depends: [
   "ocaml" {>= "5.2" & < "5.3"}
-  "dune" {>= "2.9.0"}
+  "dune" {>= "3.0.0"}
   "csexp" {>= "1.5.1"}
   "menhir"    {dev & >= "20201216"}
   "menhirLib" {dev & >= "20201216"}

ocaml-index.opam

@@ -0,0 +1,33 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "A tool that indexes value usages from cmt files"
+description:
+  "ocaml-index should integrate with the build system to index codebase and allow tools such as Merlin to perform project-wide occurrences queries."
+maintainer: ["[email protected]"]
+authors: ["[email protected]"]
+license: "MIT"
+homepage: "https://github.com/ocaml/merlin/ocaml-index"
+bug-reports: "https://github.com/ocaml/merlin/issues"
+depends: [
+  "dune" {>= "3.0.0"}
+  "ocaml" {>= "5.2"}
+  "merlin-lib" {>= "5.1-502"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "--promote-install-files=false"
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+  ["dune" "install" "-p" name "--create-install-files" name]
+]
+dev-repo: "git+https://github.com/ocaml/merlin.git"

src/ocaml-index/CHANGES.md

@@ -0,0 +1,10 @@
+1.0 (2024-06-18)
+----------------
+
+### Added
+
+- Initial release.
+- The `aggregate`` command that finishes reduction of shapes in cmt files and
+  store the output in a single index file.
+- The `stats` command that prints information about an index file.
+- The `dump` command that prints all locs of an index.

src/ocaml-index/README.md

@@ -0,0 +1,62 @@
+# 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 _output_file_] _cmt_file_ ... _index_file_ ... [-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 _index_file_ ...
+
+Or only print the number of definitions it stores:
+
+> ocaml-index stats _index_file_ ...
+
+```bash
+$ 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
+```

src/ocaml-index/bin/dune

@@ -0,0 +1,9 @@
+(executable
+ (name ocaml_index)
+ (public_name ocaml-index)
+ (package ocaml-index)
+ (libraries lib ocaml_typing merlin_index_format)
+ (flags
+  :standard
+  -open Ocaml_typing
+  -open Merlin_index_format))

src/ocaml-index/bin/ocaml_index.ml

@@ -0,0 +1,105 @@
+(** The indexer's binary *)
+
+open Lib
+
+let usage_msg =
+  "ocaml-index [COMMAND] [-verbose] <file1> [<file2>] ... -o <output>"
+
+let verbose = ref false
+let debug = ref false
+let input_files = ref []
+let build_path = ref []
+let output_file = ref "project.ocaml-index"
+let root = ref ""
+let rewrite_root = ref false
+let store_shapes = ref false
+let do_not_use_cmt_loadpath = ref false
+
+type command = Aggregate | Dump | Stats
+
+let parse_command = function
+  | "aggregate" -> Some Aggregate
+  | "dump" -> Some Dump
+  | "stats" -> Some Stats
+  | _ -> None
+
+let command = ref None
+
+let anon_fun arg =
+  match !command with
+  | None -> (
+      match parse_command arg with
+      | Some cmd -> command := Some cmd
+      | None ->
+          command := Some Aggregate;
+          input_files := arg :: !input_files)
+  | Some _ -> input_files := arg :: !input_files
+
+let speclist =
+  [
+    ("--verbose", Arg.Set verbose, "Output more information");
+    ("--debug", Arg.Set debug, "Output debugging information");
+    ("-o", Arg.Set_string output_file, "Set output file name");
+    ( "--root",
+      Arg.Set_string root,
+      "Set the root path for all relative locations" );
+    ( "--rewrite-root",
+      Arg.Set rewrite_root,
+      "Rewrite locations paths using the provided root" );
+    ( "--store-shapes",
+      Arg.Set store_shapes,
+      "Aggregate input-indexes shapes and store them in the new index" );
+    ( "-I",
+      Arg.String (fun arg -> build_path := arg :: !build_path),
+      "An extra directory to add to the load path" );
+    ( "--no-cmt-load-path",
+      Arg.Set do_not_use_cmt_loadpath,
+      "Do not initialize the load path with the paths found in the first input \
+       cmt file" );
+  ]
+
+let set_log_level debug verbose =
+  Log.set_log_level Error;
+  if verbose then Log.set_log_level Warning;
+  if debug then Log.set_log_level Debug
+
+let () =
+  Arg.parse speclist anon_fun usage_msg;
+  set_log_level !debug !verbose;
+  (match !command with
+  | Some Aggregate ->
+      let root = if String.equal "" !root then None else Some !root in
+      Index.from_files ~store_shapes:!store_shapes ~root
+        ~rewrite_root:!rewrite_root ~output_file:!output_file
+        ~build_path:!build_path
+        ~do_not_use_cmt_loadpath:!do_not_use_cmt_loadpath !input_files
+  | Some Dump ->
+      List.iter
+        (fun file ->
+          Index_format.(
+            read_exn ~file |> pp Format.std_formatter))
+        !input_files
+  | Some Stats ->
+      List.iter
+        (fun file ->
+          let open Merlin_index_format.Index_format in
+          let { defs; approximated; cu_shape; root_directory; _ } =
+            read_exn ~file
+          in
+          Printf.printf
+            "Index %S contains:\n\
+             - %i definitions\n\
+             - %i locations\n\
+             - %i approximated definitions\n\
+             - %i compilation units shapes\n\
+             - root dir: %s\n\n"
+            file (Uid_map.cardinal defs)
+            (Uid_map.fold
+               (fun _uid locs acc -> acc + Lid_set.cardinal locs)
+               defs 0)
+            (Uid_map.cardinal approximated)
+            (Hashtbl.length cu_shape)
+            (Option.value ~default:"none" root_directory))
+        !input_files
+  | _ -> Printf.printf "Nothing to do.\n%!");
+  exit 0

src/ocaml-index/lib/dune

@@ -0,0 +1,17 @@
+(library
+ (name lib)
+ (libraries
+  ocaml_typing
+  ocaml_parsing
+  ocaml_utils
+  merlin_utils
+  merlin_analysis
+  merlin_index_format)
+ (flags
+  :standard
+  -open Ocaml_typing
+  -open Ocaml_parsing
+  -open Ocaml_utils
+  -open Merlin_utils
+  -open Merlin_analysis
+  -open Merlin_index_format))