[Bug debug/48229] DW_TAG_type_unit has no DW_AT_producer

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48229

--- Comment #2 from Dodji Seketeli <dodji at gcc dot gnu.org> 2011-03-23 11:28:28 UTC ---
This is a very lightly tested patch to add the DW_AT_producer
attribute to the DW_TAG_type_unit DIE.

diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index f62bb48..ff1adc3 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -6498,6 +6498,7 @@ static inline int local_scope_p (dw_die_ref);
 static inline int class_scope_p (dw_die_ref);
 static inline int class_or_namespace_scope_p (dw_die_ref);
 static void add_type_attribute (dw_die_ref, tree, int, int, dw_die_ref);
+static void add_producer_attribute (dw_die_ref);
 static void add_calling_convention_attribute (dw_die_ref, tree);
 static const char *type_tag (const_tree);
 static tree member_declared_type (const_tree);
@@ -10298,6 +10299,13 @@ break_out_comdat_types (dw_die_ref die)
         unit = new_die (DW_TAG_type_unit, NULL, NULL);
         add_AT_unsigned (unit, DW_AT_language,
                          get_AT_unsigned (comp_unit_die (), DW_AT_language));
+
+    /* Add a DW_AT_producer attribute.  This is not mandated by
+       the DWARF-4 specification.  But it appears that GDB needs
+       it for cases where different DW_TAG_type_unit DIEs might
+       be emitted by different compilers.  */
+    add_producer_attribute (unit);
+
         type_node = ggc_alloc_cleared_comdat_type_node ();
         type_node->root_die = unit;
         type_node->next = comdat_type_list;
@@ -18014,6 +18022,28 @@ add_type_attribute (dw_die_ref object_die, tree type,
int decl_const,
     add_AT_die_ref (object_die, DW_AT_type, type_die);
 }

+/* Add an DW_AT_producer attribute to a given DIE.  */
+
+static void
+add_producer_attribute (dw_die_ref die)
+{
+  char producer[250];
+  const char *language_string = lang_hooks.name;
+  
+   sprintf (producer, "%s %s", language_string, version_string);
+#ifdef MIPS_DEBUGGING_INFO
+  /* The MIPS/SGI compilers place the 'cc' command line options in the
producer
+     string.  The SGI debugger looks for -g, -g1, -g2, or -g3; if they do
+     not appear in the producer string, the debugger reaches the conclusion
+     that the object file is stripped and has no debugging information.
+     To get the MIPS/SGI debugger to believe that there is debugging
+     information in the object file, we add a -g to the producer string.  */
+  if (debug_info_level > DINFO_LEVEL_TERSE)
+    strcat (producer, " -g");
+#endif
+  add_AT_string (die, DW_AT_producer, producer);
+}
+
 /* Given an object die, add the calling convention attribute for the
    function call type.  */
 static void
@@ -20101,7 +20131,6 @@ static dw_die_ref
 gen_compile_unit_die (const char *filename)
 {
   dw_die_ref die;
-  char producer[250];
   const char *language_string = lang_hooks.name;
   int language;

@@ -20114,21 +20143,8 @@ gen_compile_unit_die (const char *filename)
       if (!IS_ABSOLUTE_PATH (filename) && filename[0] != '<')
     add_comp_dir_attribute (die);
     }
-
-  sprintf (producer, "%s %s", language_string, version_string);
-
-#ifdef MIPS_DEBUGGING_INFO
-  /* The MIPS/SGI compilers place the 'cc' command line options in the
producer
-     string.  The SGI debugger looks for -g, -g1, -g2, or -g3; if they do
-     not appear in the producer string, the debugger reaches the conclusion
-     that the object file is stripped and has no debugging information.
-     To get the MIPS/SGI debugger to believe that there is debugging
-     information in the object file, we add a -g to the producer string.  */
-  if (debug_info_level > DINFO_LEVEL_TERSE)
-    strcat (producer, " -g");
-#endif
-
-  add_AT_string (die, DW_AT_producer, producer);
+  
+  add_producer_attribute (die);

   /* If our producer is LTO try to figure out a common language to use
      from the global list of translation units.  */