[Bug c++/77338] [7 Regression] ICE on invalid C++11 code on x86_64-linux-gnu: Segmentation fault

["su at cs dot ucdavis.edu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77338

--- Comment #2 from Zhendong Su <su at cs dot ucdavis.edu> ---
(In reply to Marek Polacek from comment #1)
> I can't reproduce:
> 
> $ ./cc1plus -quiet q.C
> q.C:3:51: error: no match for call to ‘(S) (S&)’
>  template < typename > auto f (S s)->decltype (s (s));
>                                                    ^
> q.C:3:51: error: no match for call to ‘(S) (S&)’

Marek, I still see the ICE with r239693: 

$ g++-trunk -v
Using built-in specs.
COLLECT_GCC=g++-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 7.0.0 20160823 (experimental) [trunk revision 239693] (GCC) 
$ 
$ g++-trunk -c small.cpp
small.cpp:3:51: internal compiler error: Segmentation fault
 template < typename > auto f (S s)->decltype (s (s));
                                                   ^
0xdd6b2f crash_signal
        ../../gcc-source-trunk/gcc/toplev.c:335
0x749d4b tree_check
        ../../gcc-source-trunk/gcc/tree.h:3025
0x749d4b is_really_empty_class(tree_node*)
        ../../gcc-source-trunk/gcc/cp/class.c:8447
0x8b7822 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3750
0x8bdb99 cxx_eval_outermost_constant_expr
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4390
0x8c10ee fold_non_dependent_expr(tree_node*)
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4669
0x6c98d4 build_non_dependent_expr(tree_node*)
        ../../gcc-source-trunk/gcc/cp/pt.c:23818
0x821b40 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
        ../../gcc-source-trunk/gcc/cp/semantics.c:2329
0x798770 cp_parser_postfix_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:6937
0x79992d cp_parser_decltype_expr
        ../../gcc-source-trunk/gcc/cp/parser.c:13266
0x79992d cp_parser_decltype
        ../../gcc-source-trunk/gcc/cp/parser.c:13367
0x797be7 cp_parser_simple_type_specifier
        ../../gcc-source-trunk/gcc/cp/parser.c:16258
0x793e61 cp_parser_type_specifier
        ../../gcc-source-trunk/gcc/cp/parser.c:16049
0x7963d2 cp_parser_type_specifier_seq
        ../../gcc-source-trunk/gcc/cp/parser.c:20184
0x7a0ab2 cp_parser_type_id_1
        ../../gcc-source-trunk/gcc/cp/parser.c:20046
0x7a0276 cp_parser_trailing_type_id
        ../../gcc-source-trunk/gcc/cp/parser.c:20118
0x7a0276 cp_parser_late_return_type_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:19958
0x7a0276 cp_parser_direct_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:19147
0x7a0276 cp_parser_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:18967
0x7b6025 cp_parser_init_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:18512
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$