http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60574
Bug ID: 60574
Summary: [4.9 Regression] [c++1y] ICE with deduced return type
in virtual function and LTO
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code, lto
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: reichelt at gcc dot gnu.org
The following questionable code snippet (compiled with
"-std=c++1y -flto -fpermissive") triggers an ICE on trunk:
========================
struct A
{
virtual auto foo() {}
};
struct B : A
{
auto foo();
};
B b;
========================
bug.cc:3:20: warning: virtual function cannot have deduced return type
[-fpermissive]
virtual auto foo() {}
^
bug.cc:11:4: internal compiler error: tree code 'template_type_parm' is not
supported in LTO streams
B b;
^
0xabb20e DFS_write_tree
../../gcc/gcc/lto-streamer-out.c:1300
0xaba575 DFS_write_tree_body
../../gcc/gcc/lto-streamer-out.c:476
0xaba575 DFS_write_tree
../../gcc/gcc/lto-streamer-out.c:1208
0xaba575 DFS_write_tree_body
../../gcc/gcc/lto-streamer-out.c:476
0xaba575 DFS_write_tree
../../gcc/gcc/lto-streamer-out.c:1208
0xabc8d7 lto_output_tree(output_block*, tree_node*, bool, bool)
../../gcc/gcc/lto-streamer-out.c:1390
0xab6c7f write_global_stream
../../gcc/gcc/lto-streamer-out.c:2100
0xabeb1e lto_output_decl_state_streams
../../gcc/gcc/lto-streamer-out.c:2144
0xabeb1e produce_asm_for_decls()
../../gcc/gcc/lto-streamer-out.c:2429
0xb00eff write_lto
../../gcc/gcc/passes.c:2297
0xb03f48 ipa_write_summaries_1
../../gcc/gcc/passes.c:2356
0xb03f48 ipa_write_summaries()
../../gcc/gcc/passes.c:2413
0x894044 ipa_passes
../../gcc/gcc/cgraphunit.c:2078
0x894044 compile()
../../gcc/gcc/cgraphunit.c:2174
0x8942f4 finalize_compilation_unit()
../../gcc/gcc/cgraphunit.c:2329
0x68d46e cp_write_global_declarations()
../../gcc/gcc/cp/decl2.c:4610
Please submit a full bug report, [etc.]
In GCC 4.8.x the code was rejected.
