[Bug c++/86353] New: g++7 -std=c++17 ICEs as internal compiler error: in gimplify_expr, at gimplify.c:12201

[slyfox at inbox dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86353

            Bug ID: 86353
           Summary: g++7 -std=c++17 ICEs as internal compiler error: in
                    gimplify_expr, at gimplify.c:12201
           Product: gcc
           Version: 7.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: slyfox at inbox dot ru
  Target Milestone: ---

Original bug is reported at https://bugs.gentoo.org/659480 by Cyp

Slightly shortened version of reproducer:

  // $ cat gcc-bug.ii 
  struct a {
    a() = default;
  };
  template <typename b> struct c {
    a d[3];
    constexpr c(b);
  };
  template <typename b> constexpr c<b>::c(b) {}
  c e(1);

  $ bin/g++ -std=c++17 -c gcc-bug.ii
  gcc-bug.ii: In function 'void __static_initialization_and_destruction_0(int,
int)':
  gcc-bug.ii:9:6: internal compiler error: in gimplify_expr, at
gimplify.c:12201
   c e(1);
      ^
  Please submit a full bug report,
  with preprocessed source if appropriate.
  See <https://gcc.gnu.org/bugs/> for instructions.

This is a vanilla gcc built from gcc-7-branch

  $ bin/g++ -v
  Using built-in specs.
  COLLECT_GCC=bin/g++
 
COLLECT_LTO_WRAPPER=/home/slyfox/dev/git/gcc-7-native-quick-installed/bin/../libexec/gcc/x86_64-pc-linux-gnu/7.3.1/lto-wrapper
  Target: x86_64-pc-linux-gnu
  Configured with: ../gcc-7/configure --enable-languages=c,c++ --disable-nls
--disable-bootstrap --with-multilib-list=m64
--prefix=/home/slyfox/dev/git/gcc-7-native-quick/../gcc-7-native-quick-installed
--disable-nls CFLAGS=-O2 CXXFLAGS=-O2
  Thread model: posix
  gcc version 7.3.1 20180628 (GCC)