[PATCH, PR 60600] Handle inconsistent devirtualizations gracefully
Martin Jambor
mjambor@suse.cz
Tue Mar 25 18:24:00 GMT 2014
Hi,
the following patch converting an assert to a test fixes PR 60600. If
we determine that a devirtualization cannot happen, we can now convert
the call to builtin_unreachable.
Bootstrapped and tested on x86_64-linux. I have also sucessfully LTO
built Firefox with the change. Pre-approved by Honza in bugzilla and
thus I will commit it shortly.
Thanks,
Martin
2014-03-25 Martin Jambor <mjambor@suse.cz>
PR ipa/60600
* ipa-cp.c (ipa_get_indirect_edge_target_1): Redirect type
inconsistent devirtualizations to __builtin_unreachable.
testsuite/
* g++.dg/ipa/pr60600.C: New test.
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index b71048a..74042ad 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -1639,11 +1639,18 @@ ipa_get_indirect_edge_target_1 (struct cgraph_edge *ie,
return NULL_TREE;
target = gimple_get_virt_method_for_binfo (token, binfo);
}
-#ifdef ENABLE_CHECKING
- if (target)
- gcc_assert (possible_polymorphic_call_target_p
- (ie, cgraph_get_node (target)));
-#endif
+
+ if (target && !possible_polymorphic_call_target_p (ie,
+ cgraph_get_node (target)))
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ "Type inconsident devirtualization: %s/%i->%s\n",
+ ie->caller->name (), ie->caller->order,
+ IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (target)));
+ target = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
+ cgraph_get_create_node (target);
+ }
return target;
}
diff --git a/gcc/testsuite/g++.dg/ipa/pr60600.C b/gcc/testsuite/g++.dg/ipa/pr60600.C
new file mode 100644
index 0000000..00c368e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/pr60600.C
@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fdump-ipa-cp" } */
+
+struct data {
+ data(int);
+};
+
+struct top {
+ virtual int topf();
+};
+
+struct intermediate: top {
+ int topf() /* override */ { return 0; }
+};
+
+struct child1: top {
+ void childf()
+ {
+ data d(topf());
+ }
+};
+
+struct child2: intermediate {};
+
+void test(top& t)
+{
+ child1& c = static_cast<child1&>(t);
+ c.childf();
+ child2 d;
+ test(d);
+}
+
+/* { dg-final { scan-ipa-dump "Type inconsident devirtualization" "cp" } } */
+/* { dg-final { cleanup-ipa-dump "cp" } } */
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