2009-12-15  Jakub Jelinek  <jakub@redhat.com>

	* dwarf2out.c (loc_descriptor): For SYMBOL_REFs and LABEL_REFs
	use DW_OP_addr+DW_OP_stack_value instead of DW_OP_implicit_value.
	(add_const_value_attribute): For CONST_STRING, SYMBOL_REFs and
	LABEL_REFs use DW_OP_addr+DW_OP_stack_value DW_AT_location instead of
	DW_AT_const_value.

	* gcc.dg/debug/dwarf2/const-1.c: Don't expect DW_AT_const_value,
	but instead DW_AT_location with DW_OP_addr+DW_OP_stack_value.  Add
	-gno-strict-dwarf -fno-merge-debug-strings to dg-options.
	* g++.dg/debug/dwarf2/const1.C: Likewise.

--- gcc/dwarf2out.c.jj	2009-12-14 17:55:28.000000000 +0100
+++ gcc/dwarf2out.c	2009-12-14 22:33:32.000000000 +0100
@@ -13775,10 +13775,10 @@ loc_descriptor (rtx rtl, enum machine_mo
       if (mode != VOIDmode && GET_MODE_SIZE (mode) == DWARF2_ADDR_SIZE
 	  && (dwarf_version >= 4 || !dwarf_strict))
 	{
-	  loc_result = new_loc_descr (DW_OP_implicit_value,
-				      DWARF2_ADDR_SIZE, 0);
-	  loc_result->dw_loc_oprnd2.val_class = dw_val_class_addr;
-	  loc_result->dw_loc_oprnd2.v.val_addr = rtl;
+	  loc_result = new_loc_descr (DW_OP_addr, 0, 0);
+	  loc_result->dw_loc_oprnd1.val_class = dw_val_class_addr;
+	  loc_result->dw_loc_oprnd1.v.val_addr = rtl;
+	  add_loc_descr (&loc_result, new_loc_descr (DW_OP_stack_value, 0, 0));
 	  VEC_safe_push (rtx, gc, used_rtx_array, rtl);
 	}
       break;
@@ -15223,10 +15223,20 @@ add_const_value_attribute (dw_die_ref di
       return true;
 
     case CONST_STRING:
-      resolve_one_addr (&rtl, NULL);
-      add_AT_addr (die, DW_AT_const_value, rtl);
-      VEC_safe_push (rtx, gc, used_rtx_array, rtl);
-      return true;
+      if (dwarf_version >= 4 || !dwarf_strict)
+	{
+	  dw_loc_descr_ref loc_result;
+	  resolve_one_addr (&rtl, NULL);
+	rtl_addr:
+	  loc_result = new_loc_descr (DW_OP_addr, 0, 0);
+	  loc_result->dw_loc_oprnd1.val_class = dw_val_class_addr;
+	  loc_result->dw_loc_oprnd1.v.val_addr = rtl;
+	  add_loc_descr (&loc_result, new_loc_descr (DW_OP_stack_value, 0, 0));
+	  add_AT_loc (die, DW_AT_location, loc_result);
+	  VEC_safe_push (rtx, gc, used_rtx_array, rtl);
+	  return true;
+	}
+      return false;
 
     case CONST:
       if (CONSTANT_P (XEXP (rtl, 0)))
@@ -15236,9 +15246,9 @@ add_const_value_attribute (dw_die_ref di
       if (!const_ok_for_output (rtl))
 	return false;
     case LABEL_REF:
-      add_AT_addr (die, DW_AT_const_value, rtl);
-      VEC_safe_push (rtx, gc, used_rtx_array, rtl);
-      return true;
+      if (dwarf_version >= 4 || !dwarf_strict)
+	goto rtl_addr;
+      return false;
 
     case PLUS:
       /* In cases where an inlined instance of an inline function is passed
--- gcc/testsuite/gcc.dg/debug/dwarf2/const-1.c.jj	2009-09-30 12:19:16.000000000 +0200
+++ gcc/testsuite/gcc.dg/debug/dwarf2/const-1.c	2009-12-15 10:57:48.000000000 +0100
@@ -1,7 +1,7 @@
 /* { dg-do compile } */
-/* { dg-options "-O -gdwarf-2 -dA" } */
+/* { dg-options "-O -gdwarf-2 -dA -gno-strict-dwarf -fno-merge-debug-strings" } */
 /* { dg-require-visibility "" } */
-/* { dg-final { scan-assembler "DW_AT_const_value" } } */
+/* { dg-final { scan-assembler "DW_AT_location\[^\\r\\n\]*\[\\r\\n\]*\[^\\r\\n\]*DW_OP_addr\[^\\r\\n\]*\[\\r\\n\]*\[^\\r\\n\]*fnx\[^\\r\\n\]*\[\\r\\n\]*\[^\\r\\n\]*DW_OP_stack_value" } } */
 
-extern void x() __attribute__((visibility("hidden")));
-static void (*f)() = x;
+extern void fnx() __attribute__((visibility("hidden")));
+static void (*f)() = fnx;
--- gcc/testsuite/g++.dg/debug/dwarf2/const1.C.jj	2009-09-30 12:19:16.000000000 +0200
+++ gcc/testsuite/g++.dg/debug/dwarf2/const1.C	2009-12-15 11:02:24.000000000 +0100
@@ -1,7 +1,7 @@
 /* { dg-do compile } */
-/* { dg-options "-O -gdwarf-2 -dA" } */
+/* { dg-options "-O -gdwarf-2 -dA -gno-strict-dwarf -fno-merge-debug-strings" } */
 /* { dg-require-visibility "" } */
-/* { dg-final { scan-assembler "DW_AT_const_value" } } */
+/* { dg-final { scan-assembler "DW_AT_location\[^\\r\\n\]*\[\\r\\n\]*\[^\\r\\n\]*DW_OP_addr\[^\\r\\n\]*\[\\r\\n\]*\[^\\r\\n\]*fnx\[^\\r\\n\]*\[\\r\\n\]*\[^\\r\\n\]*DW_OP_stack_value" } } */
 
-extern void x () __attribute__((visibility ("hidden")));
-void (* const f) () = x;
+extern void fnx () __attribute__((visibility ("hidden")));
+void (* const f) () = fnx;