Implement support for Ada interface types.

* ada-lang.c (ada_is_dispatch_table_ptr_type): New function.
        (ada_is_ignored_field): Ignore fields that are a dispatch table
        of a tagged type.

gdb/ChangeLog

@@ -1,3 +1,11 @@
+2008-01-01  Joel Brobecker  <brobecker@adacore.com>
+
+	Implement support for Ada interface types.
+
+	* ada-lang.c (ada_is_dispatch_table_ptr_type): New function.
+	(ada_is_ignored_field): Ignore fields that are a dispatch table
+	of a tagged type.
+
 2008-01-01  Joel Brobecker  <brobecker@adacore.com>
 
 	* top.c (print_gdb_version): Update copyright year.

gdb/ada-lang.c

@@ -5277,6 +5277,24 @@ ada_add_block_symbols (struct obstack *obstackp,
 
                                 /* Field Access */
 
+/* Return non-zero if TYPE is a pointer to the GNAT dispatch table used
+   for tagged types.  */
+
+static int
+ada_is_dispatch_table_ptr_type (struct type *type)
+{
+  char *name;
+
+  if (TYPE_CODE (type) != TYPE_CODE_PTR)
+    return 0;
+
+  name = TYPE_NAME (TYPE_TARGET_TYPE (type));
+  if (name == NULL)
+    return 0;
+
+  return (strcmp (name, "ada__tags__dispatch_table") == 0);
+}
+
 /* True if field number FIELD_NUM in struct or union type TYPE is supposed
    to be invisible to users.  */
 
@@ -5285,12 +5303,30 @@ ada_is_ignored_field (struct type *type, int field_num)
 {
   if (field_num < 0 || field_num > TYPE_NFIELDS (type))
     return 1;
-  else
-    {
-      const char *name = TYPE_FIELD_NAME (type, field_num);
-      return (name == NULL
-              || (name[0] == '_' && strncmp (name, "_parent", 7) != 0));
-    }
+   
+  /* Check the name of that field.  */
+  {
+    const char *name = TYPE_FIELD_NAME (type, field_num);
+
+    /* Anonymous field names should not be printed.
+       brobecker/2007-02-20: I don't think this can actually happen
+       but we don't want to print the value of annonymous fields anyway.  */
+    if (name == NULL)
+      return 1;
+
+    /* A field named "_parent" is internally generated by GNAT for
+       tagged types, and should not be printed either.  */
+    if (name[0] == '_' && strncmp (name, "_parent", 7) != 0)
+      return 1;
+  }
+
+  /* If this is the dispatch table of a tagged type, then ignore.  */
+  if (ada_is_tagged_type (type, 1)
+      && ada_is_dispatch_table_ptr_type (TYPE_FIELD_TYPE (type, field_num)))
+    return 1;
+
+  /* Not a special field, so it should not be ignored.  */
+  return 0;
 }
 
 /* True iff TYPE has a tag field.  If REFOK, then TYPE may also be a