[cleanup] Unify all calls to the error function.

This is the continuation of #244, we now deprecate `CErrors.error`,
the single entry point in Coq is `user_err`.

The rationale is to allow for easier grepping, and to ease a future
cleanup of error messages. In particular, we would like to
systematically classify all error messages raised by Coq and be sure
they are properly documented.

We restore the two functions removed in #244 to improve compatibility,
but mark them deprecated.

2 files changed, 7 insertions, 7 deletions

diff --git a/plugins/omega/coq_omega.ml b/plugins/omega/coq_omega.ml
index 334baec8d5..d3ca874bdd 100644
--- a/plugins/omega/coq_omega.ml
+++ b/plugins/omega/coq_omega.ml
@@ -456,7 +456,7 @@ let destructurate_prop sigma t =
 	Kapp (Other (string_of_path (path_of_global (IndRef isp))),args)
     | Var id,[] -> Kvar id
     | Prod (Anonymous,typ,body), [] -> Kimp(typ,body)
-    | Prod (Name _,_,_),[] -> error "Omega: Not a quantifier-free goal"
+    | Prod (Name _,_,_),[] -> CErrors.user_err Pp.(str "Omega: Not a quantifier-free goal")
     | _ -> Kufo
 
 let destructurate_type sigma t =
@@ -891,7 +891,7 @@ let rec scalar p n = function
          (Lazy.force coq_fast_Zmult_assoc_reverse);
        focused_simpl (P_APP 2 :: p)],
       Otimes(t1,Oz (n*x))
-  | Otimes(t1,t2) -> error "Omega: Can't solve a goal with non-linear products"
+  | Otimes(t1,t2) -> CErrors.user_err Pp.(str "Omega: Can't solve a goal with non-linear products")
   | (Oatom _ as t) -> [], Otimes(t,Oz n)
   | Oz i -> [focused_simpl p],Oz(n*i)
   | Oufo c -> [], Oufo (mkApp (Lazy.force coq_Zmult, [| mk_integer n; c |]))
@@ -943,7 +943,7 @@ let rec negate p = function
       [clever_rewrite p [[P_APP 1;P_APP 1];[P_APP 1;P_APP 2]]
          (Lazy.force coq_fast_Zopp_mult_distr_r);
        focused_simpl (P_APP 2 :: p)], Otimes(t1,Oz (neg x))
-  | Otimes(t1,t2) -> error "Omega: Can't solve a goal with non-linear products"
+  | Otimes(t1,t2) -> CErrors.user_err Pp.(str "Omega: Can't solve a goal with non-linear products")
   | (Oatom _ as t) ->
       let r = Otimes(t,Oz(negone)) in
       [clever_rewrite p [[P_APP 1]] (Lazy.force coq_fast_Zopp_eq_mult_neg_1)], r
@@ -1026,7 +1026,7 @@ let shrink_pair p f1 f2 =
     | t1,t2 ->
 	begin
 	  oprint t1; print_newline (); oprint t2; print_newline ();
-	  flush Pervasives.stdout; error "shrink.1"
+	  flush Pervasives.stdout; CErrors.user_err Pp.(str "shrink.1")
 	end
 
 let reduce_factor p = function
@@ -1038,10 +1038,10 @@ let reduce_factor p = function
       let rec compute = function
         | Oz n -> n
 	| Oplus(t1,t2) -> Bigint.add (compute t1) (compute t2)
-	| _ -> error "condense.1"
+	| _ -> CErrors.user_err Pp.(str "condense.1")
       in
       [focused_simpl (P_APP 2 :: p)], Otimes(Oatom v,Oz(compute c))
-  | t -> oprint t; error "reduce_factor.1"
+  | t -> oprint t; CErrors.user_err Pp.(str "reduce_factor.1")
 
 let rec condense p = function
   | Oplus(f1,(Oplus(f2,r) as t)) ->
diff --git a/plugins/omega/g_omega.ml4 b/plugins/omega/g_omega.ml4
index 6b711a1761..ce7ffb1e7e 100644
--- a/plugins/omega/g_omega.ml4
+++ b/plugins/omega/g_omega.ml4
@@ -35,7 +35,7 @@ let omega_tactic l =
        | "positive" -> eval_tactic "zify_positive"
        | "N" -> eval_tactic "zify_N"
        | "Z" -> eval_tactic "zify_op"
-       | s -> CErrors.error ("No Omega knowledge base for type "^s))
+       | s -> CErrors.user_err Pp.(str ("No Omega knowledge base for type "^s)))
     (Util.List.sort_uniquize String.compare l)
   in
   Tacticals.New.tclTHEN