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

[su at cs dot ucdavis.edu]

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

            Bug ID: 77338
           Summary: ICE on invalid C++11 code on x86_64-linux-gnu:
                    Segmentation fault
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

This is a regression from 6.x. 


$ 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 20160822 (experimental) [trunk revision 239655] (GCC) 
$ 
$ g++-trunk -c small.cpp
small.cpp:3:51: internal compiler error: Segmentation fault
 template < typename > auto f (S s)->decltype (s (s));
                                                   ^
0xdd5bff crash_signal
        ../../gcc-source-trunk/gcc/toplev.c:335
0x749d5b tree_check
        ../../gcc-source-trunk/gcc/tree.h:3022
0x749d5b is_really_empty_class(tree_node*)
        ../../gcc-source-trunk/gcc/cp/class.c:8447
0x8b7832 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3750
0x8bdba9 cxx_eval_outermost_constant_expr
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4390
0x8c10fe fold_non_dependent_expr(tree_node*)
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4669
0x6c98e4 build_non_dependent_expr(tree_node*)
        ../../gcc-source-trunk/gcc/cp/pt.c:23818
0x821b50 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
        ../../gcc-source-trunk/gcc/cp/semantics.c:2329
0x798780 cp_parser_postfix_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:6937
0x79993d cp_parser_decltype_expr
        ../../gcc-source-trunk/gcc/cp/parser.c:13266
0x79993d cp_parser_decltype
        ../../gcc-source-trunk/gcc/cp/parser.c:13367
0x797bf7 cp_parser_simple_type_specifier
        ../../gcc-source-trunk/gcc/cp/parser.c:16258
0x793e71 cp_parser_type_specifier
        ../../gcc-source-trunk/gcc/cp/parser.c:16049
0x7963e2 cp_parser_type_specifier_seq
        ../../gcc-source-trunk/gcc/cp/parser.c:20184
0x7a0ac2 cp_parser_type_id_1
        ../../gcc-source-trunk/gcc/cp/parser.c:20046
0x7a0286 cp_parser_trailing_type_id
        ../../gcc-source-trunk/gcc/cp/parser.c:20118
0x7a0286 cp_parser_late_return_type_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:19958
0x7a0286 cp_parser_direct_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:19147
0x7a0286 cp_parser_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:18967
0x7b6035 cp_parser_init_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:18512
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.
$ 


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struct S; //OK: struct S {  void operator () (S); }; 

template < typename > auto f (S s)->decltype (s (s));