re PR c++/26965 (Unnecessary debug info for unused consts in C++)

	PR debug/26965
	* dwarf2out.c (gen_variable_die): Don't worry about DECL_COMDAT.
	Don't emit a second declaration at any scope.

From-SVN: r154157

gcc/ChangeLog

+2009-11-13  Jason Merrill  <jason@redhat.com>
+
+	PR debug/26965
+	* dwarf2out.c (gen_variable_die): Don't worry about DECL_COMDAT.
+	Don't emit a second declaration at any scope.
+
 2009-11-13  Andrey Belevantsev  <abel@ispras.ru>
 
         PR rtl-optimization/41697

gcc/dwarf2out.c

@@ -17926,26 +17926,6 @@ gen_variable_die (tree decl, tree origin, dw_die_ref context_die)
   dw_die_ref old_die = decl ? lookup_decl_die (decl) : NULL;
   dw_die_ref origin_die;
   int declaration = (DECL_EXTERNAL (decl_or_origin)
-		     /* If DECL is COMDAT and has not actually been
-			emitted, we cannot take its address; there
-			might end up being no definition anywhere in
-			the program.  For example, consider the C++
-			test case:
-
-			  template <class T>
-			  struct S { static const int i = 7; };
-
-			  template <class T>
-			  const int S<T>::i;
-
-			  int f() { return S<int>::i; }
-
-			Here, S<int>::i is not DECL_EXTERNAL, but no
-			definition is required, so the compiler will
-			not emit a definition.  */
-		     || (TREE_CODE (decl_or_origin) == VAR_DECL
-			 && DECL_COMDAT (decl_or_origin)
-			 && !TREE_ASM_WRITTEN (decl_or_origin))
 		     || class_or_namespace_scope_p (context_die));
 
   if (!origin)
@@ -18059,8 +18039,7 @@ gen_variable_die (tree decl, tree origin, dw_die_ref context_die)
      and if we already emitted a DIE for it, don't emit a second
      DIE for it again.  */
   if (old_die
-      && declaration
-      && old_die->die_parent == context_die)
+      && declaration)
     return;
 
   /* For static data members, the declaration in the class is supposed

gcc/testsuite/ChangeLog

 2009-11-13  Jason Merrill  <jason@redhat.com>
 
+	PR debug/26965
+	* g++.dg/debug/dwarf2/static-data-member2.C: New.
+
 	PR c++/35075
 	* g++.dg/template/ref5.C: New.
 

gcc/testsuite/g++.dg/debug/dwarf2/static-data-member2.C

+// PR debug/26965
+// { dg-options "-gdwarf-2 -dA" }
+// { dg-final { scan-assembler-not "DW_TAG_variable" } }
+// { dg-final { scan-assembler-not "DW_TAG_enumerator" } }
+// { dg-final { scan-assembler-not "DW_TAG_enumeration_type" } }
+
+enum x { i = 1 };
+class c {
+  static const x beg = i;
+  int foo () { return (int) beg; }
+};
+void bar () { }