expose Printexc.format_backtrace_slot to facilitate testing

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14781 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

stdlib/printexc.ml

@@ -106,7 +106,7 @@ let convert_raw_backtrace rbckt =
   try Some (Array.map convert_raw_backtrace_slot rbckt)
   with Failure _ -> None
 
-let format_loc_info pos li =
+let format_backtrace_slot pos li =
   let is_raise =
     match li with
     | Known_location(is_raise, _, _, _, _) -> is_raise
@@ -133,7 +133,7 @@ let print_exception_backtrace outchan backtrace =
   | Some a ->
       for i = 0 to Array.length a - 1 do
         if a.(i) <> Unknown_location true then
-          fprintf outchan "%s\n" (format_loc_info i a.(i))
+          fprintf outchan "%s\n" (format_backtrace_slot i a.(i))
       done
 
 let print_raw_backtrace outchan raw_backtrace =
@@ -151,7 +151,7 @@ let backtrace_to_string backtrace =
       let b = Buffer.create 1024 in
       for i = 0 to Array.length a - 1 do
         if a.(i) <> Unknown_location true then
-          bprintf b "%s\n" (format_loc_info i a.(i))
+          bprintf b "%s\n" (format_backtrace_slot i a.(i))
       done;
       Buffer.contents b
 

stdlib/printexc.mli

@@ -139,6 +139,18 @@ type backtrace_slot =
 *)
 val convert_raw_backtrace_slot: raw_backtrace_slot -> backtrace_slot
 
+(** [format_backtrace_slot pos slot] returns the string
+    representation of the backtrace slot [slot] as
+    [raw_backtrace_to_string] would format it, assuming it is the
+    [pos]-th element of the backtrace: the 0-th element is
+    pretty-printed differently than the other.
+
+    Note that Printexc's printing function will skip any slot equal to
+    [Unknown_location true]; you should as well if you wish to
+    reproduce its behavior.
+*)
+val format_backtrace_slot : int -> backtrace_slot -> string
+
 (** {6 Current call stack} *)
 
 val get_callstack: int -> raw_backtrace