feature(rules): custom alias for cinaps

Allow setting the alias used to run cinaps actions.

This is done to override the behavior of attaching the cinaps action to
both the `cinaps` and `runtest` aliases.

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>

<!-- ps-id: d35a6315-e4ef-40d1-9527-783dcd82029a -->

CHANGES.md

@@ -114,6 +114,10 @@ Unreleased
 - Fix dependency cycle when installing files to the bin section with
   `glob_files` (#6764, fixes #6708, @gridbugs)
 
+- Allow the `cinaps` stanza to set a custom alias. By default, if the alias is
+  not set then the cinaps actions will be attached to both `@cinaps` and
+  `@runtest` (#6988, @rgrinberg)
+
 3.6.2 (2022-12-21)
 ------------------
 

src/dune_rules/cinaps.ml

@@ -8,17 +8,21 @@ type t =
   ; preprocessor_deps : Dep_conf.t list
   ; runtime_deps : Dep_conf.t list
   ; cinaps_version : Syntax.Version.t
+  ; alias : Alias.Name.t option
   }
 
 let name = "cinaps"
 
+let cinaps_alias = Alias.Name.of_string name
+
 type Stanza.t += T of t
 
 let syntax =
   Dune_lang.Syntax.create ~name ~desc:"the cinaps extension"
-    [ ((1, 0), `Since (1, 11)); ((1, 1), `Since (3, 5)) ]
-
-let alias = Alias.make (Alias.Name.of_string name)
+    [ ((1, 0), `Since (1, 11))
+    ; ((1, 1), `Since (3, 5))
+    ; ((1, 2), `Since (3, 7))
+    ]
 
 let decode =
   let open Dune_lang.Decoder in
@@ -33,6 +37,7 @@ let decode =
        field ~default:[] "runtime_deps"
          (Dune_lang.Syntax.since syntax (1, 1) >>> repeat Dep_conf.decode)
      and+ cinaps_version = Dune_lang.Syntax.get_exn syntax
+     and+ alias = field_o "alias" Alias.Name.decode
      (* TODO use this field? *)
      and+ _flags = Ocaml_flags.Spec.decode in
      { loc
@@ -42,6 +47,7 @@ let decode =
      ; preprocessor_deps
      ; runtime_deps
      ; cinaps_version
+     ; alias
      })
 
 let () =
@@ -160,9 +166,14 @@ let gen_rules sctx t ~dir ~scope =
                      (Path.Build.extend_basename fn ~suffix:".cinaps-corrected"))
             ))
   in
-  let cinaps_alias = alias ~dir in
+  let cinaps_alias =
+    Alias.make ~dir @@ Option.value t.alias ~default:cinaps_alias
+  in
   let* () =
     Super_context.add_alias_action sctx ~dir ~loc:(Some loc) cinaps_alias action
   in
-  Rules.Produce.Alias.add_deps (Alias.runtest ~dir)
-    (Action_builder.alias cinaps_alias)
+  match t.alias with
+  | Some _ -> Memo.return ()
+  | None ->
+    Rules.Produce.Alias.add_deps (Alias.runtest ~dir)
+      (Action_builder.alias cinaps_alias)

test/blackbox-tests/test-cases/cinaps/custom-alias.t

@@ -0,0 +1,21 @@
+Custom alias for the cinaps
+
+  $ cat > dune-project <<EOF
+  > (lang dune 3.7)
+  > (using cinaps 1.2)
+  > EOF
+
+  $ cat > dune <<EOF
+  > (cinaps
+  >  (files foo.ml)
+  >  (alias foo))
+  > EOF
+
+  $ touch foo.ml
+
+  $ dune build @foo --display short
+        cinaps .cinaps.a7811055/cinaps.ml-gen
+        ocamlc .cinaps.a7811055/.cinaps.eobjs/byte/dune__exe__Cinaps.{cmi,cmo,cmt}
+      ocamlopt .cinaps.a7811055/.cinaps.eobjs/native/dune__exe__Cinaps.{cmx,o}
+      ocamlopt .cinaps.a7811055/cinaps.exe
+        cinaps alias foo