[Bug c++/57658] ICE in tsubst_copy, at cp/pt.c:12213

[t-gcc-bugzilla at snowelm dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57658

--- Comment #3 from Takaki Makino <t-gcc-bugzilla at snowelm dot com> ---
Created attachment 30336
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30336&action=edit
Reduced testcase

Hi Paolo,
Thank you for referring to the useful resource.
Using these tools I've got a reduced version (attached)
I believe this is a valid code.

$ g++-4.9 -std=c++11  testcase.cpp
testcase.cpp: In instantiation of 'X<T>::f() [with T = int]::<lambda()>':
testcase.cpp:11:11:   required from 'struct X<T>::f() [with T =
int]::<lambda()>'
testcase.cpp:11:9:   required from 'bool X<T>::f() [with T = int]'
testcase.cpp:16:16:   required from here
testcase.cpp:12:62: internal compiler error: in tsubst_copy, at cp/pt.c:12213
             typename remove_reference < decltype (a) >::type t;
                                                              ^
0x59f7f0 tsubst_copy
        ../../gcc/cp/pt.c:12213
0x57cee9 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/cp/pt.c:14484
0x59081c tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:11807
0x59c8fa tsubst_template_args
        ../../gcc/cp/pt.c:9640
0x59d2fe tsubst_aggr_type
        ../../gcc/cp/pt.c:9837
0x590a25 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:11695
0x5a1581 tsubst_decl
        ../../gcc/cp/pt.c:10652
0x5913b4 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:11101
0x586eef tsubst_expr
        ../../gcc/cp/pt.c:12931
0x587284 tsubst_expr
        ../../gcc/cp/pt.c:13070
0x5864b3 tsubst_expr
        ../../gcc/cp/pt.c:12880
0x587284 tsubst_expr
        ../../gcc/cp/pt.c:13070
0x584e5b instantiate_decl(tree_node*, int, bool)
        ../../gcc/cp/pt.c:19112
0x5bcb67 instantiate_class_template_1
        ../../gcc/cp/pt.c:9018
0x5bcb67 instantiate_class_template(tree_node*)
        ../../gcc/cp/pt.c:9086
0x647dcb complete_type(tree_node*)
        ../../gcc/cp/typeck.c:131
0x57dd30 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/cp/pt.c:14581
0x586a12 tsubst_expr
        ../../gcc/cp/pt.c:13415
0x586f6f tsubst_expr
        ../../gcc/cp/pt.c:12894
0x5864b3 tsubst_expr
        ../../gcc/cp/pt.c:12880
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.