[Bug c++/82650] New: -fdump-go-spec Segmentation fault on enums

[avshash at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82650

            Bug ID: 82650
           Summary: -fdump-go-spec Segmentation fault on enums
           Product: gcc
           Version: 6.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: avshash at hotmail dot com
  Target Milestone: ---

Using the '-fdump-go-spec' flag causes Segmentation fault when program has any
enum definition on c++ files.
Example:
---------------------------------------------------
enum dummy_t
{
  DUMMY_ENUM
};

int main ()
{
  return 0
}
----------------------------------------------------
command line - g++ main.cc -fdump-go-spec=dummy.go
----------------------------------------------------
reason is the difference in enum tree between C and C++

Patch in 'godump.c', function 'go_output_typedef'
(correct fix should be a proper function)
-----------------------------------------------------
ADD:
tree integer_cst = TREE_VALUE (element);
if (TREE_CODE (integer_cst) == CONST_DECL) {
  integer_cst = DECL_INITIAL (integer_cst);
}
if (TREE_CODE (integer_cst) != INTEGER_CST) {
  internal_error ("...");
}

CHANGE:
if (tree_fits_shwi_p (integer_cst)) {
            // CHANGE ^^^^^^^^^^^
  snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DEC,
            tree_to_shwi (integer_cst));
            // CHANGE     ^^^^^^^^^^^
}
else if (tree_fits_uhwi_p (integer_cst)) {
            // CHANGE      ^^^^^^^^^^^
  snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED,
            tree_to_uhwi (integer_cst));
            // CHANGE     ^^^^^^^^^^^
}
else {
  print_hex (wi::to_wide (integer_cst, buf));
            // CHANGE     ^^^^^^^^^^^
            // the last one is also a bug in the C branch,
            // where there is a 'TREE_VALUE' missing
            // but unreachable code on my machine.
}