[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.

3 files changed, 17 insertions, 5 deletions

diff --git a/lib/cErrors.ml b/lib/cErrors.ml
index b55fd80c6..b0e77a4c9 100644
--- a/lib/cErrors.ml
+++ b/lib/cErrors.ml
@@ -38,7 +38,6 @@ exception UserError of string option * std_ppcmds (* User errors *)
 let todo s = prerr_string ("TODO: "^s^"\n")
 
 let user_err ?loc ?hdr strm = Loc.raise ?loc (UserError (hdr, strm))
-let error            string = user_err (str string)
 
 let invalid_arg ?loc s   = Loc.raise ?loc (Invalid_argument s)
 
@@ -138,3 +137,8 @@ let handled e =
   let bottom _ = raise Bottom in
   try let _ = print_gen bottom !handle_stack e in true
   with Bottom -> false
+
+(* Deprecated functions *)
+let error            string = user_err (str string)
+let user_err_loc (loc,hdr,msg) = user_err ~loc ~hdr msg
+let errorlabstrm hdr msg = user_err ~hdr msg
diff --git a/lib/cErrors.mli b/lib/cErrors.mli
index 0665a8ce7..ca0838575 100644
--- a/lib/cErrors.mli
+++ b/lib/cErrors.mli
@@ -41,9 +41,6 @@ val user_err : ?loc:Loc.t -> ?hdr:string -> std_ppcmds -> 'a
 (** Main error raising primitive. [user_err ?loc ?hdr pp] signals an
     error [pp] with optional header and location [hdr] [loc] *)
 
-val error : string -> 'a
-(** [error s] just calls [user_error "_" (str s)] *)
-
 exception AlreadyDeclared of std_ppcmds
 val alreadydeclared : std_ppcmds -> 'a
 
@@ -98,3 +95,14 @@ val noncritical : exn -> bool
 (** Check whether an exception is handled by some toplevel printer. The
     [Anomaly] exception is never handled. *)
 val handled : exn -> bool
+
+(** Deprecated functions  *)
+val error : string -> 'a
+ [@@ocaml.deprecated "use [user_err] instead"]
+
+val errorlabstrm : string -> std_ppcmds -> 'a
+ [@@ocaml.deprecated "use [user_err ~hdr] instead"]
+
+val user_err_loc : Loc.t * string * std_ppcmds -> 'a
+ [@@ocaml.deprecated "use [user_err ~loc] instead"]
+
diff --git a/lib/cWarnings.ml b/lib/cWarnings.ml
index 2755946ab..d004fd671 100644
--- a/lib/cWarnings.ml
+++ b/lib/cWarnings.ml
@@ -86,7 +86,7 @@ let parse_flag s =
     | '+' -> (AsError, String.sub s 1 (String.length s - 1))
     | '-' -> (Disabled, String.sub s 1 (String.length s - 1))
     | _ -> (Enabled, s)
-  else CErrors.error "Invalid warnings flag"
+  else CErrors.user_err Pp.(str "Invalid warnings flag")
 
 let string_of_flag (status,name) =
   match status with