[Bug c++/71972] New: ICE with "-std=c++14" on x86_64-linux-gnu (internal compiler error: Segmentation fault, cxx_eval_store_expression)

[chengniansun at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71972

            Bug ID: 71972
           Summary: ICE with "-std=c++14" on x86_64-linux-gnu (internal
                    compiler error: Segmentation fault,
                    cxx_eval_store_expression)
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: chengniansun at gmail dot com
  Target Milestone: ---

$ 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 20160722 (experimental) [trunk revision 238645] (GCC)
$
$ g++-trunk -std=c++14 small.C
small.C: In instantiation of ‘auto concat(S<N>, S<M>) [with int N = 1; int M =
1]’:
small.C:14:16:   required from here
small.C:10:59:   in constexpr expansion of ‘s.S<N>::S<1>(s1.S<1>::data)’
small.C:10:59: internal compiler error: Segmentation fault
 template <int N, int M> auto concat(S<N> s1, S<M>) { S<1> s(s1.data); }
                                                           ^
0xdb18cf crash_signal
        ../../gcc-source-trunk/gcc/toplev.c:335
0x8be3b5 cxx_eval_store_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3238
0x8bbf7d cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3741
0x8baee6 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4026
0x8bb120 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3780
0x8bb120 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3780
0x8c1306 cxx_eval_statement_list
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3438
0x8bb6e0 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4082
0x8bbe8a cxx_eval_loop_expr
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3470
0x8bbe8a cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4159
0x8c1306 cxx_eval_statement_list
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3438
0x8bb6e0 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4082
0x8c1306 cxx_eval_statement_list
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3438
0x8bb6e0 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4082
0x8bb241 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4088
0x8bb241 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4088
0x8c1306 cxx_eval_statement_list
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3438
0x8bb6e0 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4082
0x8bb241 cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4088
0x8c1306 cxx_eval_statement_list
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3438
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.
$
$ cat small.C
typedef int size_t;
template <int N> struct S {
  template <size_t M> constexpr S(char (&)[M]) : data{} {
    for (size_t i = 0;;)
      data[i] = data[i];
  }
  char data[N];
};
template <int N> S<N> s(char const (&)[N]);
template <int N, int M> auto concat(S<N> s1, S<M>) { S<1> s(s1.data); }
int main() {
  auto s1 = s("");
  auto s2 = s("");
  concat(s1, s2);
  return 0;
}
$