A more reasonable implementation of Loadpath.

The new behaviour is simple: either a path is in the loadpaths or it is not.
No more wild expansions of paths!

This should not affect -R and -Q, but it does change the semantics of -I -as.
Still, there are no more users of it and it only does so in a subtle way.

1 files changed, 14 insertions, 34 deletions

diff --git a/library/loadpath.ml b/library/loadpath.ml
index ab8b0a307..0f7c2fb46 100644
--- a/library/loadpath.ml
+++ b/library/loadpath.ml
@@ -93,47 +93,27 @@ let expand_root_path dir =
   let rec aux = function
   | [] -> []
   | p :: l ->
-    if p.path_root && is_dirpath_prefix_of p.path_logical dir then
-      let suffix = drop_dirpath_prefix p.path_logical dir in
-      extend_path_with_dirpath p.path_physical suffix :: aux l
+    if DirPath.equal p.path_logical dir then p.path_physical :: aux l
     else aux l
   in
   aux !load_paths
 
-(* Root p is bound to A.B.C.D and we require file C.D.E.F *)
-(* We may mean A.B.C.D.E.F, or A.B.C.D.C.D.E.F *)
-
-(* Root p is bound to A.B.C.C and we require file C.C.E.F *)
-(* We may mean A.B.C.C.E.F, or A.B.C.C.C.E.F, or A.B.C.C.C.C.E.F *)
-
-let intersections d1 d2 =
-  let rec aux d1 =
-    if DirPath.is_empty d1 then [d2] else
-      let rest = aux (snd (chop_dirpath 1 d1)) in
-      if is_dirpath_prefix_of d1 d2 then drop_dirpath_prefix d1 d2 :: rest
-      else rest in
-  aux d1
-
-let expand p dir =
-  let ph = extend_path_with_dirpath p.path_physical dir in
-  let log = append_dirpath p.path_logical dir in
-  (ph, log)
+let is_suffix dir1 dir2 =
+  let dir1 = DirPath.repr dir1 in
+  let dir2 = DirPath.repr dir2 in
+  List.prefix_of Id.equal dir1 dir2
 
 let expand_path dir =
   let rec aux = function
   | [] -> []
   | p :: l ->
-    match p.path_implicit, p.path_root with
-    | true, false -> expand p dir :: aux l
-    | true, true ->
-      let inters = intersections p.path_logical dir in
-      List.map (expand p) inters @ aux l
-    | false, true ->
-      if is_dirpath_prefix_of p.path_logical dir then
-	expand p (drop_dirpath_prefix p.path_logical dir) :: aux l
-      else aux l
-    | false, false ->
-      (* nothing to do, an explicit root path should also match above
-         if [is_dirpath_prefix_of p.path_logical dir] were true here *)
-      aux l in
+    let { path_physical = ph; path_logical = lg } = p in
+    match p.path_implicit with
+    | true ->
+      (** The path is implicit, so that we only want match the logical suffix *)
+      if is_suffix dir lg then (ph, lg) :: aux l else aux l
+    | false ->
+      (** Otherwise we must match exactly *)
+      if DirPath.equal dir lg then (ph, lg) :: aux l else aux l
+  in
   aux !load_paths