[Bug middle-end/55797] [4.8 Regression] ICE: verify_cgraph_node failed: edge has no corresponding call_stmt

["hubicka at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55797

--- Comment #8 from Jan Hubicka <hubicka at gcc dot gnu.org> 2013-01-23 13:56:44 UTC ---
This is not really issue with early inliner confused with function not being in
SSA form.  But for aid of esra, we can do that at expense of increasing of peak
memory use - the SSA form is quite bloated just after built and early passes
gets it noticeably smaller, so we may need to schedule another DCE pass or so.

The problem here is however saving body of
file_info::~file_info() (struct file_info * const this)
{
  struct intrusive_ptr * _2;
  struct intrusive_ptr * _5;
  struct intrusive_ptr * _7;
  struct section_info * _9;

  <bb 2>:
  _2 = &this_1(D)->switched_section;
  _9 = _2->px;
  if (_9 != 0B)
    goto <bb 3>;
  else
    goto <bb 5> (<L2>);

  <bb 3>:
  section_info::~section_info (_9);

  <bb 4>:
  operator delete (_9);

<L2>:
  _5 = &this_1(D)->parent;
  intrusive_ptr<file_info>::~intrusive_ptr (_5);
  return;

<L1>:
  _7 = &this_1(D)->parent;
  intrusive_ptr<file_info>::~intrusive_ptr (_7);
  resx 1

}

The basic block <L1> in unreachable, but for some reason it is not removed
prior inlining.  save_function_body must run delete_unreachable_blocks in order
to update SSA after copying and that one gets rid of the call. It updates the
node itself, but not the clones.  I will add code to update clones. 

I suppose this is because