PR 62026 (4.9-branch version)

[Jan Hubicka]

Hi,
the ICE is caused by duplicate_thunk_for_node not copying DECL_ARGUMENTS in LTO
mode because they are not streamed in. This is gcc-4.9 branch version of the fix,
I will prepare mainline version shortly.

Bootstrapped/regtested x86_64-linux, comitted.

PR lto/62026
* g++.dg/lto/pr62026.C: New testcase.
* lto-streamer-out.c (lto_output): Handle thunks correctly.
* cgraphclones.c (duplicate_thunk_for_node): Get thunk's arguments.
Index: testsuite/g++.dg/lto/pr62026.C
===================================================================
--- testsuite/g++.dg/lto/pr62026.C (revision 0)
+++ testsuite/g++.dg/lto/pr62026.C (revision 0)
@@ -0,0 +1,22 @@
+// { dg-lto-do link }
+// { dg-lto-options {{-flto -O3 -r -nostdlib}} }
+class C;
+class F {
+ virtual C m_fn1();
+};
+class C {
+ public:
+ virtual int *m_fn3(int);
+};
+class G : F, C {
+ int offsets;
+ int *m_fn3(int);
+};
+C *a;
+int *G::m_fn3(int) {
+ if (offsets) return 0;
+}
+
+void fn1() {
+ for (;;) a->m_fn3(0);
+}
Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c (revision 215890)
+++ lto-streamer-out.c (working copy)
@@ -2077,7 +2077,10 @@ lto_output (void)
#endif
decl_state = lto_new_out_decl_state ();
lto_push_out_decl_state (decl_state);
- if (gimple_has_body_p (node->decl) || !flag_wpa)
+ if (gimple_has_body_p (node->decl) || !flag_wpa
+ /* Thunks have no body but they may be synthetized
+ at WPA time. */
+ || DECL_ARGUMENTS (node->decl))
output_function (node);
else
copy_function (node);
Index: cgraphclones.c
===================================================================
--- cgraphclones.c (revision 215890)
+++ cgraphclones.c (working copy)
@@ -310,6 +310,11 @@ duplicate_thunk_for_node (cgraph_node *t
if (thunk_of->thunk.thunk_p)
node = duplicate_thunk_for_node (thunk_of, node);

+ /* We need to copy arguments, at LTO these mat not be read from function
+ section. */
+ if (!DECL_ARGUMENTS (thunk->decl))
+ cgraph_get_body (thunk);
+
struct cgraph_edge *cs;
for (cs = node->callers; cs; cs = cs->next_caller)
if (cs->caller->thunk.thunk_p