[Bug c++/82054] [8 Regression] ICE in add_dwarf_attr with -fopenmp and -g

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82054

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hmpf, that DW_AT_object_pointer thing is tricky ;)  Ah... first generated by

#6  0x000000000101629a in expand_omp_taskreg (region=0x2c19ab0)
    at /tmp/trunk2/gcc/omp-expand.c:1313
1313            (*debug_hooks->early_global_decl) (cfun->decl);
(gdb) l
1308            block = gimple_block (entry_stmt);
1309
1310          /* Make sure to generate early debug for the function before
1311             outlining anything.  */
1312          if (! gimple_in_ssa_p (cfun))
1313            (*debug_hooks->early_global_decl) (cfun->decl);

and then again via

#6  0x0000000000c72825 in symbol_table::finalize_compilation_unit (
    this=0x7ffff6895100) at /tmp/trunk2/gcc/cgraphunit.c:2623
2623            (*debug_hooks->early_global_decl) (cnode->decl);
(gdb) l
2618        {
2619          /* Emit early debug for reachable functions, and by consequence,
2620             locally scoped symbols.  */
2621          struct cgraph_node *cnode;
2622          FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (cnode)
2623            (*debug_hooks->early_global_decl) (cnode->decl);

The following resolves this, testing in progress.

Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c     (revision 251553)
+++ gcc/dwarf2out.c     (working copy)
@@ -25492,9 +25492,10 @@ dwarf2out_early_global_decl (tree decl)
   if (TREE_CODE (decl) != TYPE_DECL
       && TREE_CODE (decl) != PARM_DECL)
     {
-      tree save_fndecl = current_function_decl;
       if (TREE_CODE (decl) == FUNCTION_DECL)
        {
+         tree save_fndecl = current_function_decl;
+
          /* For nested functions, make sure we have DIEs for the parents first
             so that all nested DIEs are generated at the proper scope in the
             first shot.  */
@@ -25521,11 +25522,19 @@ dwarf2out_early_global_decl (tree decl)
              dwarf2out_decl (origin);
            }

-         current_function_decl = decl;
+         /* Emit the DIE for decl but avoid doing that multiple times.  */
+         dw_die_ref old_die;
+         if ((old_die = lookup_decl_die (decl)) == NULL
+             || is_declaration_die (old_die))
+           {
+             current_function_decl = decl;
+             dwarf2out_decl (decl);
+           }
+
+         current_function_decl = save_fndecl;
        }
-      dwarf2out_decl (decl);
-      if (TREE_CODE (decl) == FUNCTION_DECL)
-       current_function_decl = save_fndecl;
+      else
+       dwarf2out_decl (decl);
     }
   symtab->global_info_ready = save;
 }