Getting rid of Exninfo hacks.

Instead of modifying exceptions to wear additional information, we instead use
a dedicated type now. All exception-using functions were modified to support
this new type, in particular Future's fix_exn-s and the tactic monad.

To solve the problem of enriching exceptions at raise time and recover this
data in the try-with handler, we use a global datastructure recording the
given piece of data imperatively that we retrieve in the try-with handler.
We ensure that such instrumented try-with destroy the data so that there
may not be confusion with another exception. To further harden the correction
of this structure, we also check for pointer equality with the last raised
exception.

The global data structure is not thread-safe for now, which is incorrect as
the STM uses threads and enriched exceptions. Yet, we splitted the patch in
two parts, so that we do not introduce dependencies to the Thread library
immediatly. This will allow to revert only the second patch if ever we
switch to OCaml-coded lightweight threads.

1 files changed, 7 insertions, 5 deletions

diff --git a/plugins/funind/indfun.ml b/plugins/funind/indfun.ml
index 2ce9f4f616..6dbd61cfdd 100644
--- a/plugins/funind/indfun.ml
+++ b/plugins/funind/indfun.ml
@@ -217,6 +217,8 @@ let prepare_body ((name,_,args,types,_),_) rt =
   let fun_args,rt' = chop_rlambda_n n rt in
   (fun_args,rt')
 
+let process_vernac_interp_error e =
+  fst (Cerrors.process_vernac_interp_error (e, Exninfo.null))
 
 let derive_inversion fix_names =
   try
@@ -243,23 +245,23 @@ let derive_inversion fix_names =
 	   fix_names
 	)
     with e when Errors.noncritical e ->
-      let e' = Cerrors.process_vernac_interp_error e in
+      let e' = process_vernac_interp_error e in
       msg_warning
 	(str "Cannot build inversion information" ++
 	   if do_observe () then (fnl() ++ Errors.print e') else mt ())
   with e when Errors.noncritical e -> ()
 
 let warning_error names e =
-  let e = Cerrors.process_vernac_interp_error e in
+  let e = process_vernac_interp_error e in
   let e_explain e =
     match e with
       | ToShow e -> 
-	let e = Cerrors.process_vernac_interp_error e in
+	let e = process_vernac_interp_error e in
 	spc () ++ Errors.print e
       | _ -> 
 	if do_observe () 
 	then 
-	  let e = Cerrors.process_vernac_interp_error e in 
+	  let e = process_vernac_interp_error e in 
 	  (spc () ++ Errors.print e) 
 	else mt ()
   in
@@ -277,7 +279,7 @@ let warning_error names e =
     | _ -> raise e
 
 let error_error names e =
-  let e = Cerrors.process_vernac_interp_error e in
+  let e = process_vernac_interp_error e in
   let e_explain e =
     match e with
       | ToShow e -> spc () ++ Errors.print e