[Bug gcov-profile/98631] exception hit once reported twice

[marxin at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98631

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
                 CC|                            |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-01-12

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Thank you Marek for the report, I can confirm it.
What happens:

$ g++ pr98631.C --coverage -fdump-ipa-profile-details-lineno
...
int main ()
{
  struct S s;
  int D.2411;
  void * _1;
  int _11;

  <bb 2> :
  [pr98631.C:14:7] S::S ([pr98631.C:14:7] &s);

  <bb 3> :
  s ={v} {CLOBBER};

  <bb 4> :
  [pr98631.C:19:1] _11 = 0;

  <bb 5> :
<L1>:
  [pr98631.C:19:1] return _11;

  <bb 6> :
<L2>:
  s ={v} {CLOBBER};
  resx 2

  <bb 7> :
<L3>:
  [pr98631.C:16:3] eh_dispatch 1

  <bb 8> :
<L4>:
  [pr98631.C:16:9] _1 = __builtin_eh_pointer (1);
  [pr98631.C:16:9] __cxa_begin_catch (_1);

  <bb 9> :
  [pr98631.C:17:22] __builtin_puts (&"caught"[0]);

  <bb 10> :
  [pr98631.C:16:9] __cxa_end_catch ();
  goto <bb 4>; [INV]

  <bb 11> :
<L5>:
  [pr98631.C:16:9] __cxa_end_catch ();

  <bb 12> :
  resx 4

}

        -:   15:  }
        2:   16:  catch(...) {
        1:   17:    __builtin_printf ("caught\n");
        -:   18:  }

In my case line 16 is present in BB 7, 8, 10 and 11.

$ gcov a-pr98631.C -t --debug

source_info: pr98631.C
  function_info: main
    block_info id=0, count=1
    block_info id=1, count=1
    block_info id=2, count=1
    block_info id=3, count=0
    block_info id=4, count=1
    block_info id=5, count=1
    block_info id=6, count=1
    block_info id=7, count=1
    block_info id=8, count=1
    block_info id=9, count=1
    block_info id=10, count=1
    block_info id=11, count=0
    block_info id=12, count=0

as seen, bb_9 is executed and that's the place where we "leave" line 16,
enter line 17 and then again enter 16 in bb_10. That's why we see the line
being executed twise.

It's not easy to fix :/
Btw. started with r5-7298-g3b445b24ddadf8a9.