re-commit Leo's weak-dependencies pull request

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14755 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 31 insertions, 11 deletions

diff --git a/typing/env.ml b/typing/env.ml
index 247e060f2..f7ef02d22 100644
--- a/typing/env.ml
+++ b/typing/env.ml
@@ -286,7 +286,7 @@ type pers_struct =
   { ps_name: string;
     ps_sig: signature;
     ps_comps: module_components;
-    ps_crcs: (string * Digest.t) list;
+    ps_crcs: (string * Digest.t option) list;
     ps_filename: string;
     ps_flags: pers_flags list;
     mutable ps_crcs_checked: bool }
@@ -297,12 +297,25 @@ let persistent_structures =
 (* Consistency between persistent structures *)
 
 let crc_units = Consistbl.create()
+let imported_units = ref ([] : string list)
+
+let clear_imports () =
+  Consistbl.clear crc_units;
+  imported_units := []
+
+let add_imports ps =
+  List.iter
+    (fun (name, _) -> imported_units := name :: !imported_units)
+    ps.ps_crcs
 
 let check_consistency ps =
   if ps.ps_crcs_checked then () else
   try
     List.iter
-      (fun (name, crc) -> Consistbl.check crc_units name crc ps.ps_filename)
+      (fun (name, crco) ->
+         match crco with
+            None -> ()
+          | Some crc -> Consistbl.check crc_units name crc ps.ps_filename)
       ps.ps_crcs;
     ps.ps_crcs_checked <- true
   with Consistbl.Inconsistency(name, source, auth) ->
@@ -330,6 +343,7 @@ let read_pers_struct modname filename =
              ps_flags = flags } in
   if ps.ps_name <> modname then
     error (Illegal_renaming(modname, ps.ps_name, filename));
+  add_imports ps;
   if not !Clflags.transparent_modules then check_consistency ps;
   List.iter
     (function Rectypes ->
@@ -364,7 +378,7 @@ let find_pers_struct ?(check=true) name =
 let reset_cache () =
   current_unit := "";
   Hashtbl.clear persistent_structures;
-  Consistbl.clear crc_units;
+  clear_imports ();
   Hashtbl.clear value_declarations;
   Hashtbl.clear type_declarations;
   Hashtbl.clear used_constructors;
@@ -1564,15 +1578,20 @@ let read_signature modname filename =
 
 let crc_of_unit name =
   let ps = find_pers_struct ~check:false name in
-  try
-    List.assoc name ps.ps_crcs
-  with Not_found ->
-    assert false
+  let crco =
+    try
+      List.assoc name ps.ps_crcs
+    with Not_found ->
+      assert false
+  in
+    match crco with
+      None -> assert false
+    | Some crc -> crc
 
 (* Return the list of imported interfaces with their CRCs *)
 
-let imported_units() =
-  Consistbl.extract crc_units
+let imports() =
+  Consistbl.extract !imported_units crc_units
 
 (* Save a signature to a file *)
 
@@ -1601,12 +1620,13 @@ let save_signature_with_imports sg modname filename imports =
       { ps_name = modname;
         ps_sig = sg;
         ps_comps = comps;
-        ps_crcs = (cmi.cmi_name, crc) :: imports;
+        ps_crcs = (cmi.cmi_name, Some crc) :: imports;
         ps_filename = filename;
         ps_flags = cmi.cmi_flags;
         ps_crcs_checked = true } in
     Hashtbl.add persistent_structures modname (Some ps);
     Consistbl.set crc_units modname crc filename;
+    imported_units := modname :: !imported_units;
     sg
   with exn ->
     close_out oc;
@@ -1614,7 +1634,7 @@ let save_signature_with_imports sg modname filename imports =
     raise exn
 
 let save_signature sg modname filename =
-  save_signature_with_imports sg modname filename (imported_units())
+  save_signature_with_imports sg modname filename (imports())
 
 (* Folding on environments *)