flambda-backend: Simplifications following PR #1667 (#1668)

A couple of small simplifications that are obvious by themselves but would have
made #1667 a bit harder to review:

  * `Env.sign_of_cmi` is only called via `read_sign_of_cmi` with
    `~freshen:true`, so just rename `sign_of_cmi` to `read_sign_of_cmi` and
    freshen unconditionally

  * `Persistent_env.save_pers_struct` requires a `pers_struct` but doesn't use
    all of it, so split out its arguments

Author: lukemaurer

typing/env.ml

@@ -926,7 +926,7 @@ let components_of_module ~alerts ~uid env ps path addr mty shape =
     }
   }
 
-let sign_of_cmi ~freshen { Persistent_env.Persistent_signature.cmi; _ } =
+let read_sign_of_cmi { Persistent_env.Persistent_signature.cmi; _ } =
   let name = cmi.cmi_name in
   let sign = cmi.cmi_sign in
   let flags = cmi.cmi_flags in
@@ -954,10 +954,8 @@ let sign_of_cmi ~freshen { Persistent_env.Persistent_signature.cmi; _ } =
   let mda_components =
     let mty = Subst.Lazy.Mty_signature sign in
     let mty =
-      if freshen then
-        Subst.Lazy.modtype (Subst.Rescope (Path.scope path))
-          Subst.identity mty
-      else mty
+      Subst.Lazy.modtype (Subst.Rescope (Path.scope path))
+        Subst.identity mty
     in
     components_of_module ~alerts ~uid:md.md_uid
       empty Subst.identity
@@ -970,8 +968,6 @@ let sign_of_cmi ~freshen { Persistent_env.Persistent_signature.cmi; _ } =
     mda_shape;
   }
 
-let read_sign_of_cmi = sign_of_cmi ~freshen:true
-
 let persistent_env : module_data Persistent_env.t ref =
   s_table Persistent_env.empty ()
 

typing/persistent_env.ml

@@ -168,17 +168,17 @@ let fold {persistent_structures; _} f x =
 
 (* Reading persistent structures from .cmi files *)
 
-let save_pers_struct penv crc ps =
+let save_pers_struct penv crc comp_unit flags filename =
   let {crc_units; _} = penv in
-  let modname = CU.name ps.ps_name in
+  let modname = CU.name comp_unit in
   List.iter
     (function
         | Rectypes -> ()
         | Alerts _ -> ()
         | Unsafe_string -> ()
         | Opaque -> register_import_as_opaque penv modname)
-    ps.ps_flags;
-  Consistbl.set crc_units modname ps.ps_name crc ps.ps_filename;
+    flags;
+  Consistbl.set crc_units modname comp_unit crc filename;
   add_import penv modname
 
 let acknowledge_pers_struct penv check modname pers_sig pm =
@@ -385,7 +385,7 @@ let save_cmi penv psig =
       let {
         cmi_name = modname;
         cmi_sign = _;
-        cmi_crcs = imports;
+        cmi_crcs = _;
         cmi_flags = flags;
       } = cmi in
       let crc =
@@ -394,16 +394,7 @@ let save_cmi penv psig =
           (fun temp_filename oc -> output_cmi temp_filename oc cmi) in
       (* Enter signature in consistbl so that imports()
          will also return its crc *)
-      let ps =
-        { ps_name = modname;
-          ps_crcs =
-            Array.append
-              [| Import_info.create_normal cmi.cmi_name ~crc:(Some crc) |]
-              imports;
-          ps_filename = filename;
-          ps_flags = flags;
-        } in
-      save_pers_struct penv crc ps
+      save_pers_struct penv crc modname flags filename
     )
     ~exceptionally:(fun () -> remove_file filename)