Add more information to IllFormedRecBody exceptions, to show the exact

definition on which it is failing (useful for Program definitions and
others too).


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10533 85f007b7-540e-0410-9357-904b9bb8a0f7

5 files changed, 21 insertions, 14 deletions

diff --git a/kernel/inductive.ml b/kernel/inductive.ml
index 0b14038e3..aef3d6cc8 100644
--- a/kernel/inductive.ml
+++ b/kernel/inductive.ml
@@ -777,6 +777,8 @@ let check_one_fix renv recpos def =
   in
   check_rec_call renv def
 
+let judgment_of_fixpoint (_, types, bodies) =
+  array_map2 (fun typ body -> { uj_val = body ; uj_type = typ }) types bodies
 
 let inductive_of_mutfix env ((nvect,bodynum),(names,types,bodies as recdef)) =
   let nbfix = Array.length bodies in 
@@ -788,8 +790,9 @@ let inductive_of_mutfix env ((nvect,bodynum),(names,types,bodies as recdef)) =
     or bodynum >= nbfix
   then anomaly "Ill-formed fix term";
   let fixenv = push_rec_types recdef env in
+  let vdefj = judgment_of_fixpoint recdef in
   let raise_err env i err =
-    error_ill_formed_rec_body env err names i in
+    error_ill_formed_rec_body env err names i fixenv vdefj in
   (* Check the i-th definition with recarg k *)
   let find_ind i k def = 
     (* check fi does not appear in the k+1 first abstractions, 
@@ -815,14 +818,15 @@ let inductive_of_mutfix env ((nvect,bodynum),(names,types,bodies as recdef)) =
   (Array.map fst rv, Array.map snd rv)
 
 
-let check_fix env ((nvect,_),(names,_,bodies as _recdef) as fix) =
+let check_fix env ((nvect,_),(names,_,bodies as recdef) as fix) =
   let (minds, rdef) = inductive_of_mutfix env fix in
   for i = 0 to Array.length bodies - 1 do
     let (fenv,body) = rdef.(i) in
     let renv = make_renv fenv minds nvect.(i) minds.(i) in
     try check_one_fix renv nvect body
     with FixGuardError (fixenv,err) ->
-      error_ill_formed_rec_body fixenv err names i
+      error_ill_formed_rec_body fixenv err names i 
+	(push_rec_types recdef env) (judgment_of_fixpoint recdef)
   done
 
 (*
@@ -933,5 +937,6 @@ let check_cofix env (bodynum,(names,types,bodies as recdef)) =
     let fixenv = push_rec_types recdef env in
     try check_one_cofix fixenv nbfix bodies.(i) types.(i)
     with CoFixGuardError (errenv,err) -> 
-      error_ill_formed_rec_body errenv err names i
+      error_ill_formed_rec_body errenv err names i 
+	fixenv (judgment_of_fixpoint recdef)
   done
diff --git a/kernel/type_errors.ml b/kernel/type_errors.ml
index bbd3e4bf4..116a74947 100644
--- a/kernel/type_errors.ml
+++ b/kernel/type_errors.ml
@@ -56,7 +56,7 @@ type type_error =
   | CantApplyBadType of
       (int * constr * constr) * unsafe_judgment * unsafe_judgment array
   | CantApplyNonFunctional of unsafe_judgment * unsafe_judgment array
-  | IllFormedRecBody of guard_error * name array * int
+  | IllFormedRecBody of guard_error * name array * int * env * unsafe_judgment array
   | IllTypedRecBody of
       int * name array * unsafe_judgment array * types array
 
@@ -105,8 +105,8 @@ let error_cant_apply_not_functional env rator randl =
 let error_cant_apply_bad_type env t rator randl =
   raise (TypeError (env, CantApplyBadType (t,rator,randl)))
 
-let error_ill_formed_rec_body env why lna i =
-  raise (TypeError (env, IllFormedRecBody (why,lna,i)))
+let error_ill_formed_rec_body env why lna i fixenv vdefj =
+  raise (TypeError (env, IllFormedRecBody (why,lna,i,fixenv,vdefj)))
 
 let error_ill_typed_rec_body env i lna vdefj vargs =
   raise (TypeError (env, IllTypedRecBody (i,lna,vdefj,vargs)))
diff --git a/kernel/type_errors.mli b/kernel/type_errors.mli
index 6e480479e..38bd0d394 100644
--- a/kernel/type_errors.mli
+++ b/kernel/type_errors.mli
@@ -58,7 +58,7 @@ type type_error =
   | CantApplyBadType of
       (int * constr * constr) * unsafe_judgment * unsafe_judgment array
   | CantApplyNonFunctional of unsafe_judgment * unsafe_judgment array
-  | IllFormedRecBody of guard_error * name array * int
+  | IllFormedRecBody of guard_error * name array * int * env * unsafe_judgment array
   | IllTypedRecBody of
       int * name array * unsafe_judgment array * types array
 
@@ -96,7 +96,7 @@ val error_cant_apply_bad_type :
       unsafe_judgment -> unsafe_judgment array -> 'a
 
 val error_ill_formed_rec_body :
-  env -> guard_error -> name array -> int -> 'a
+  env -> guard_error -> name array -> int -> env -> unsafe_judgment array -> 'a
 
 val error_ill_typed_rec_body  :
   env -> int -> name array -> unsafe_judgment array -> types array -> 'a
diff --git a/tactics/decl_proof_instr.ml b/tactics/decl_proof_instr.ml
index 1d5ab017c..c4b7ad13c 100644
--- a/tactics/decl_proof_instr.ml
+++ b/tactics/decl_proof_instr.ml
@@ -1471,7 +1471,7 @@ let rec postprocess pts instr =
 	      goto_current_focus_or_top (mark_as_done pts)
  	    with 
 		Type_errors.TypeError(env,
-				      Type_errors.IllFormedRecBody(_,_,_)) ->
+				      Type_errors.IllFormedRecBody(_,_,_,_,_)) ->
 		  anomaly "\"end induction\" generated an ill-formed fixpoint"
 	end
     | Pend _ -> 
diff --git a/toplevel/himsg.ml b/toplevel/himsg.ml
index 0b69c41e7..16f3971f5 100644
--- a/toplevel/himsg.ml
+++ b/toplevel/himsg.ml
@@ -214,7 +214,7 @@ let explain_not_product env c =
 
 (* TODO: use the names *)
 (* (co)fixpoints *)
-let explain_ill_formed_rec_body env err names i =
+let explain_ill_formed_rec_body env err names i fixenv vdefj =
   let prt_name i =
     match names.(i) with
         Name id -> str "Recursive definition of " ++ pr_id id
@@ -286,9 +286,11 @@ let explain_ill_formed_rec_body env err names i =
       strbrk " not in guarded form (should be a constructor," ++
       strbrk " an abstraction, a match, a cofix or a recursive call)"
   in
+  let pvd, pvdt = pr_ljudge_env fixenv vdefj.(i) in
   prt_name i ++ str " is ill-formed." ++ fnl () ++
   pr_ne_context_of (str "In environment") env ++
-  st ++ str "."
+  st ++ str "." ++ fnl () ++
+  str"Recursive definition is:" ++ spc () ++ pvd ++ str "."
 
 let explain_ill_typed_rec_body env i names vdefj vargs =
   let env = make_all_name_different env in
@@ -436,8 +438,8 @@ let explain_type_error env err =
       explain_cant_apply_bad_type env t rator randl
   | CantApplyNonFunctional (rator, randl) ->
       explain_cant_apply_not_functional env rator randl
-  | IllFormedRecBody (err, lna, i) ->
-      explain_ill_formed_rec_body env err lna i
+  | IllFormedRecBody (err, lna, i, fixenv, vdefj) ->
+      explain_ill_formed_rec_body env err lna i fixenv vdefj
   | IllTypedRecBody (i, lna, vdefj, vargs) ->
      explain_ill_typed_rec_body env i lna vdefj vargs
   | WrongCaseInfo (ind,ci) ->