correction d'un stack overflow possible (PR#320)

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@4278 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 6 insertions, 5 deletions

diff --git a/contrib/extraction/extraction.ml b/contrib/extraction/extraction.ml
index ad20e4679..a4c2cc46e 100644
--- a/contrib/extraction/extraction.ml
+++ b/contrib/extraction/extraction.ml
@@ -31,8 +31,9 @@ open Mlutil
 
 exception I of inductive_info
 
-(* A flag used to avoid loops in [extract_inductive] *)
-let internal_call = ref (None : kernel_name option) 
+(* A set of all inductive currently being computed, 
+   to avoid loops in [extract_inductive] *)
+let internal_call = ref KNset.empty
 
 let none = Evd.empty
 
@@ -283,11 +284,11 @@ and extract_type_scheme env db c p =
 
 and extract_ind env kn = (* kn is supposed to be in long form *)
   try 
-    if (!internal_call = Some kn) then lookup_ind kn (* Already started. *)
+    if KNset.mem kn !internal_call then lookup_ind kn (* Already started. *)
     else if visible_kn kn then lookup_ind kn (* Standard situation. *)
     else raise Not_found (* Never trust the table for a internal kn. *)
   with Not_found -> 
-    internal_call := Some kn;
+    internal_call := KNset.add kn !internal_call;
     let mib = Environ.lookup_mind kn env in 
     (* Everything concerning parameters. *)
     (* We do that first, since they are common to all the [mib]. *)
@@ -374,7 +375,7 @@ and extract_ind env kn = (* kn is supposed to be in long form *)
     in
     let i = {ind_info = ind_info; ind_nparams = npar; ind_packets = packets} in 
     add_ind kn i; 
-    internal_call := None;
+    internal_call := KNset.remove kn !internal_call;
     i
 
 (*s [extract_type_cons] extracts the type of an inductive