[Bug middle-end/78689] New: [7 Regression] ICE (segfault)

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78689

            Bug ID: 78689
           Summary: [7 Regression] ICE (segfault)
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org
  Target Milestone: ---

seen with r243108 on x86_64-linux-gnu (building the yosys package in Debian),
also crashes with -O1 and -O0.

$ g++ -std=c++11 -c -O2 share.ii 
share.ii: In constructor 'e::e()':
share.ii:14:3: internal compiler error: Segmentation fault
   e() {
   ^
0xb0bb0f crash_signal
        ../../src/gcc/toplev.c:333
0xb33b03 main_block_label
        ../../src/gcc/tree-cfg.c:1380
0xb33ffd cleanup_dead_labels()
        ../../src/gcc/tree-cfg.c:1563
0xb3ec31 build_gimple_cfg
        ../../src/gcc/tree-cfg.c:237
0xb3ec31 execute_build_cfg
        ../../src/gcc/tree-cfg.c:396
0xb3ec31 execute
        ../../src/gcc/tree-cfg.c:432
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-7/README.Bugs> for instructions.

$ cat share.ii
class b {
  struct B {
    B(int, int);
  } ah;

public:
  int c;
  b(const char *) : ah(0, c) {}
};
struct d {
  d(b);
};
struct e {
  e() {
    goto aj;
    if (0)
    aj:;
  }
};
struct f : d {
  f() : d("") { e(); }
} a;