Fix various shortcomings of the warnings infrastructure.

- The flags are now interpreted from left to right, without any other
precedence rule. The previous one did not make much sense in interactive
mode.
- Set Warnings and Set Warnings Append are now synonyms, and have the
"append" semantics, which is the most natural one for warnings.
- Warnings on unknown warnings are now printed only once (previously the
would be repeated on further calls to Set Warnings, sections closing,
module requiring...).
- Warning status strings are normalized, so that e.g. "+foo,-foo" is reduced
to "-foo" (if foo exists, "" otherwise).

1 files changed, 4 insertions, 3 deletions

diff --git a/library/goptions.ml b/library/goptions.ml
index dfb3c0e69..9dc0f4058 100644
--- a/library/goptions.ml
+++ b/library/goptions.ml
@@ -247,7 +247,7 @@ let get_locality = function
   | Some false -> OptGlobal
   | None -> OptDefault
 
-let declare_option cast uncast append
+let declare_option cast uncast append ?(preprocess = fun x -> x)
   { optsync=sync; optdepr=depr; optname=name; optkey=key; optread=read; optwrite=write } =
   check_key key;
   let default = read() in
@@ -275,10 +275,11 @@ let declare_option cast uncast append
             subst_function = subst_options;
             discharge_function = discharge_options;
             classify_function = classify_options } in
-      (fun l m v -> Lib.add_anonymous_leaf (options (l, m, v)))
+      (fun l m v -> let v = preprocess v in Lib.add_anonymous_leaf (options (l, m, v)))
     else
       (fun _ m v ->
-       match m with
+        let v = preprocess v in
+        match m with
        | OptSet -> write v
        | OptAppend -> write (append (read ()) v))
   in