Hi,
On Fri, Mar 21, 2014 at 09:41:24AM +0100, Richard Biener wrote:
> On Thu, 20 Mar 2014, Martin Jambor wrote:
>
> > Hi,
> >
> > in PR 60419 we end up with a call graph node for a thunk that has no
> > callee because symtab_remove_unreachable_nodes has determined its body
> > is not needed although its declaration is still reachable (more
> > details in comment 11 in bugzilla) and removal of callees is a part of
> > the zombification process that such nodes undergo. Later on, the last
> > stage of inlining that runs after that connects the thunk to the call
> > graph and we segfault because we expect thunks to have a callee.
> >
> > So we can either keep thunk targets alive or clear the thunk flag.
> > Thunks and aliases are quite similar and
> > symtab_remove_unreachable_nodes does clear the alias flag and the "in
> > border" nodes are referred to but not output and thus just another
> > symbol. Therefore I believe it is correct and much simpler to remove
> > the thunk flag s well.
> >
> > Bootstrapped and tested on x86_64, I have also build Mozilla Firefox
> > witht the patch (without LTO, partly on purpose, partly because again
> > I'm having issues with LTO after updating FF). OK for trunk?
>
> Ok.
Thanks, I have just committed the trunk patch. A proposed 4.8 variant
is below, it does the same thing at the same spot, although there is a
number of minor differences between the branches. One of them is that
symtab_remove_unreachable_nodes does not clear any flags there in 4.8
and therefore I have added also clearing of the alias flag because
(although I do not have a testcase) just like there should not be any
thunks without callees, there also should not be any aliases without
references, cgraph_function_node would choke on them too.
Bootstrapped and tested on the 4.8 branch on x86_64-linux. OK for the
branch?
Thanks,
Martin
2014-03-20 Martin Jambor <mjam...@suse.cz>
PR ipa/60419
* ipa.c (symtab_remove_unreachable_nodes): Clear thunk and
alias flags of nodes in the border.
testsuite/
* g++.dg/ipa/pr60419.C: New test.
diff --git a/gcc/ipa.c b/gcc/ipa.c
index a9b8fb4..d73d105 100644
--- a/gcc/ipa.c
+++ b/gcc/ipa.c
@@ -359,6 +359,8 @@ symtab_remove_unreachable_nodes (bool before_inlining_p,
FILE *file)
{
if (file)
fprintf (file, " %s", cgraph_node_name (node));
+ node->alias = false;
+ node->thunk.thunk_p = false;
cgraph_node_remove_callees (node);
ipa_remove_all_references (&node->symbol.ref_list);
changed = true;
diff --git a/gcc/testsuite/g++.dg/ipa/pr60419.C
b/gcc/testsuite/g++.dg/ipa/pr60419.C
new file mode 100644
index 0000000..84461f3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/pr60419.C
@@ -0,0 +1,80 @@
+// PR middle-end/60419
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct C
+{
+};
+
+struct I : C
+{
+ I ();
+};
+
+struct J
+{
+ void foo ();
+ J ();
+ virtual void foo (int &, int);
+};
+
+template <class>
+struct D
+{
+ virtual void foo (I &) const;
+ void bar ()
+ {
+ I p;
+ foo (p);
+ }
+};
+
+struct K : J, public D<int>
+{
+};
+
+struct F
+{
+ K *operator->();
+};
+
+struct N : public K
+{
+ void foo (int &, int);
+ I n;
+ void foo (I &) const {}
+};
+
+struct L : J
+{
+ F l;
+};
+
+struct M : F
+{
+ L *operator->();
+};
+
+struct G
+{
+ G ();
+};
+
+M h;
+
+G::G ()
+try
+{
+ N f;
+ f.bar ();
+ throw;
+}
+catch (int)
+{
+}
+
+void
+baz ()
+{
+ h->l->bar ();
+}
