* src/misc/freelist.cc (free_list::remove): Work around

invalidated iterators.
* tgba/bdddict.cc (unregister_variable): New methods,
extracted from ...
(bdd_dict::unregister_all_my_variables): ... here.
* tgba/bdddict.hh (unregister_variable): Declare them.

ChangeLog

@@ -1,3 +1,12 @@
+2004-03-25  Alexandre Duret-Lutz  <adl@src.lip6.fr>
+
+	* src/misc/freelist.cc (free_list::remove): Work around
+	invalidated iterators.
+	* tgba/bdddict.cc (unregister_variable): New methods,
+	extracted from ...
+	(bdd_dict::unregister_all_my_variables): ... here.
+	* tgba/bdddict.hh (unregister_variable): Declare them.
+
 2004-03-23  Alexandre DURET-LUTZ  <adl@src.lip6.fr>
 
 	* src/misc/freelist.hh (free_list::remove, free_list::insert): New

src/misc/freelist.cc

@@ -131,13 +131,15 @@ namespace spot
   void
   free_list::remove(int base, int n)
   {
-    free_list_type::iterator cur;
+    free_list_type::iterator cur = fl.begin();
     int end = base + n;
-    for (cur = fl.begin(); cur != fl.end() && cur->first <= end; ++cur)
+    while (cur != fl.end() && cur->first <= end)
       {
 	int cend = cur->first + cur->second;
+	// Remove may invalidate the current iterator, so advance it first.
+	free_list_type::iterator old = cur++;
 	if (cend >= end)
-	  remove(cur, base, std::max(n, cend - base));
+	  remove(old, base, std::max(n, cend - base));
       }
   }
 

src/tgba/bdddict.cc

@@ -173,28 +173,30 @@ namespace spot
   }
 
   void
-  bdd_dict::unregister_all_my_variables(const void* me)
+  bdd_dict::unregister_variable(int var, const void* me)
   {
-    vr_map::iterator i;
+    vr_map::iterator i = var_refs.find(var);
-    for (i = var_refs.begin(); i != var_refs.end();)
+    assert(i != var_refs.end());
-      {
+    unregister_variable(i, me);
-	// Increment i++ now, we will possibly erase
+  }
-	// the current node (which would invalidate the iterator).
-	vr_map::iterator cur = i++;
 
+  void
+  bdd_dict::unregister_variable(vr_map::iterator& cur, const void* me)
+  {
     ref_set& s = cur->second;
     ref_set::iterator si = s.find(me);
     if (si == s.end())
-	  continue;
+      return;
     s.erase(si);
     if (! s.empty())
-	  continue;
+      return;
+
     // ME was the last user of this variable.
     // Let's free it.  First, we need to find
     // if this is a Now, a Var, or an Acc variable.
     int var = cur->first;
     int n = 1;
-	const ltl::formula* f;
+    const ltl::formula* f = 0;
     vf_map::iterator vi = var_formula_map.find(var);
     if (vi != var_formula_map.end())
       {
@@ -235,9 +237,22 @@ namespace spot
     // Actually release the associated BDD variables, and the
     // formula itself.
     release_variables(var, n);
+    if (f)
       ltl::destroy(f);
     var_refs.erase(cur);
   }
+
+  void
+  bdd_dict::unregister_all_my_variables(const void* me)
+  {
+    vr_map::iterator i;
+    for (i = var_refs.begin(); i != var_refs.end();)
+      {
+	// Increment i++ now, we will possibly erase
+	// the current node (which would invalidate the iterator).
+	vr_map::iterator cur = i++;
+	unregister_variable(cur, me);
+      }
     free_annonymous_list_of.erase(me);
   }
 

src/tgba/bdddict.hh

@@ -135,11 +135,14 @@ namespace spot
     /// is deleted if \a from_other is still alive.
     void register_all_variables_of(const void* from_other, const void* for_me);
 
-    /// \brief Release the variables used by object.
+    /// \brief Release all variables used by an object.
     ///
     /// Usually called in the destructor if \a me.
     void unregister_all_my_variables(const void* me);
 
+    /// \brief Release a variable used by \a me.
+    void unregister_variable(int var, const void* me);
+
     /// @{
     /// Check whether formula \a f has already been registered by \a by_me.
     bool is_registered_proposition(const ltl::formula* f, const void* by_me);
@@ -164,6 +167,7 @@ namespace spot
     typedef Sgi::hash_map<int, ref_set> vr_map;
     vr_map var_refs;
 
+    void unregister_variable(vr_map::iterator& cur, const void* me);
 
     class annon_free_list : public spot::free_list
     {