Hi,
I was quite surprised we still had an assert checking that the target
of a virtual call derived by ipa-cp is among possible ones derived by
ipa-devirt. This is not true for various down-casts and I managed to
trigger it in PR 61540 (where the testcase purposefully invokes
undefined behavior but we should not ICE).
Fixed thusly. Bootstrapped and tested on x86_64-linux. OK for trunk
and the 4.9 branch?
Thanks,
Martin
2014-06-17 Martin Jambor <mjam...@suse.cz>
PR ipa/61540
* ipa-prop.c (impossible_devirt_target): New function.
(try_make_edge_direct_virtual_call): Use it, also instead of
asserting.
testsuite/
* g++.dg/ipa/pr61540.C: New test.
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index b67deed..f5ec67a 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -2912,6 +2912,29 @@ try_make_edge_direct_simple_call (struct cgraph_edge *ie,
return cs;
}
+/* Return the target to be used in cases of impossible devirtualization. IE
+ and target (the latter can be NULL) are dumped when dumping is enabled. */
+
+static tree
+impossible_devirt_target (struct cgraph_edge *ie, tree target)
+{
+ if (dump_file)
+ {
+ if (target)
+ fprintf (dump_file,
+ "Type inconsident devirtualization: %s/%i->%s\n",
+ ie->caller->name (), ie->caller->order,
+ IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (target)));
+ else
+ fprintf (dump_file,
+ "No devirtualization target in %s/%i\n",
+ ie->caller->name (), ie->caller->order);
+ }
+ tree new_target = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
+ cgraph_get_create_node (new_target);
+ return new_target;
+}
+
/* Try to find a destination for indirect edge IE that corresponds to a virtual
call based on a formal parameter which is described by jump function JFUNC
and if it can be determined, make it direct and return the direct edge.
@@ -2946,15 +2969,7 @@ try_make_edge_direct_virtual_call (struct cgraph_edge
*ie,
&& DECL_FUNCTION_CODE (target) == BUILT_IN_UNREACHABLE)
|| !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);
- }
+ target = impossible_devirt_target (ie, target);
return ipa_make_edge_direct_to_target (ie, target);
}
}
@@ -2984,10 +2999,7 @@ try_make_edge_direct_virtual_call (struct cgraph_edge
*ie,
if (targets.length () == 1)
target = targets[0]->decl;
else
- {
- target = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
- cgraph_get_create_node (target);
- }
+ target = impossible_devirt_target (ie, NULL_TREE);
}
else
{
@@ -3002,10 +3014,8 @@ try_make_edge_direct_virtual_call (struct cgraph_edge
*ie,
if (target)
{
-#ifdef ENABLE_CHECKING
- gcc_assert (possible_polymorphic_call_target_p
- (ie, cgraph_get_node (target)));
-#endif
+ if (!possible_polymorphic_call_target_p (ie, cgraph_get_node (target)))
+ return ipa_make_edge_direct_to_target (ie, target);
return ipa_make_edge_direct_to_target (ie, target);
}
else
diff --git a/gcc/testsuite/g++.dg/ipa/pr61540.C
b/gcc/testsuite/g++.dg/ipa/pr61540.C
new file mode 100644
index 0000000..d298964
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/pr61540.C
@@ -0,0 +1,41 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-early-inlining -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);
+}
+
+int main (int argc, char **argv)
+{
+ child1 c;
+ test (c);
+ return 0;
+}
+
+/* { dg-final { scan-ipa-dump "Type inconsident devirtualization" "cp" } } */
+/* { dg-final { cleanup-ipa-dump "cp" } } */
