Hi,
besides the issue discussed a bit some time ago, we have got in Bugzilla
a number of other issues, all essentially dups of each other (modulo
irrelevant details, AFAICS)
c++/51488
c++/53618
c++/58059
c++/56163 (this is two bugs, the second one is dup of c++/55843)
In these the infinite recursion involves instantiate_class_template_1
but via most_specialized_class (c++/51488 has a backtrace) thus at the
beginning of the function, and we don't catch it.
To explain *in practice* what I mean, the attached patchlet p avoid all
these crashes (+ passes the testsuite as-is modulo an XPASS for line 8
of template/recurse.C).
Unfortunately, at the time I didn't follow in detail the implementation
of the push_tinst_level mechanism, now I see it used many times with
little variations, thus I definitely need further guidance (my patchlet
is loosely inspired by the use in maybe_instantiate_noexcept). In
particular, I fear memory leaks or mismanagement (I see a ggc_free
(tinst); in instantiate_alias_template which I don't fully understand).
Also, I wonder if we could provide more detailed information...
Thanks in advance!
Paolo.
///////////////////////////
Index: pt.c
===================================================================
--- pt.c (revision 201927)
+++ pt.c (working copy)
@@ -8658,7 +8658,15 @@ instantiate_class_template_1 (tree type)
/* Determine what specialization of the original template to
instantiate. */
- t = most_specialized_class (type, templ, tf_warning_or_error);
+
+ if (push_tinst_level (type))
+ {
+ t = most_specialized_class (type, templ, tf_warning_or_error);
+ pop_tinst_level ();
+ }
+ else
+ t = error_mark_node;
+
if (t == error_mark_node)
{
TYPE_BEING_DEFINED (type) = 1;
