+/* Return true if the INDEXth field of TYPE is a virtual baseclass
+ pointer which is for the base class whose type is BASECLASS. */
+
+static int
+vb_match (struct type *type, int index, struct type *basetype)
+{
+ struct type *fieldtype;
+ char *name = TYPE_FIELD_NAME (type, index);
+ char *field_class_name = NULL;
+
+ if (*name != '_')
+ return 0;
+ /* gcc 2.4 uses _vb$. */
+ if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3]))
+ field_class_name = name + 4;
+ /* gcc 2.5 will use __vb_. */
+ if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_')
+ field_class_name = name + 5;
+
+ if (field_class_name == NULL)
+ /* This field is not a virtual base class pointer. */
+ return 0;
+
+ /* It's a virtual baseclass pointer, now we just need to find out whether
+ it is for this baseclass. */
+ fieldtype = TYPE_FIELD_TYPE (type, index);
+ if (fieldtype == NULL
+ || TYPE_CODE (fieldtype) != TYPE_CODE_PTR)
+ /* "Can't happen". */
+ return 0;
+
+ /* What we check for is that either the types are equal (needed for
+ nameless types) or have the same name. This is ugly, and a more
+ elegant solution should be devised (which would probably just push
+ the ugliness into symbol reading unless we change the stabs format). */
+ if (TYPE_TARGET_TYPE (fieldtype) == basetype)
+ return 1;
+
+ if (TYPE_NAME (basetype) != NULL
+ && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL
+ && strcmp (TYPE_NAME (basetype),
+ TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))) == 0)
+ return 1;
+ return 0;
+}
+
+/* Compute the offset of the baseclass which is
+ the INDEXth baseclass of class TYPE,
+ for value at VALADDR (in host) at ADDRESS (in target).
+ The result is the offset of the baseclass value relative
+ to (the address of)(ARG) + OFFSET.
+
+ -1 is returned on error. */
+
+int
+gnuv2_baseclass_offset (struct type *type, int index, char *valaddr,
+ CORE_ADDR address)
+{
+ struct type *basetype = TYPE_BASECLASS (type, index);
+
+ if (BASETYPE_VIA_VIRTUAL (type, index))
+ {
+ /* Must hunt for the pointer to this virtual baseclass. */
+ int i, len = TYPE_NFIELDS (type);
+ int n_baseclasses = TYPE_N_BASECLASSES (type);
+
+ /* First look for the virtual baseclass pointer
+ in the fields. */
+ for (i = n_baseclasses; i < len; i++)
+ {
+ if (vb_match (type, i, basetype))
+ {
+ CORE_ADDR addr
+ = unpack_pointer (TYPE_FIELD_TYPE (type, i),
+ valaddr + (TYPE_FIELD_BITPOS (type, i) / 8));
+
+ return addr - (LONGEST) address;
+ }
+ }
+ /* Not in the fields, so try looking through the baseclasses. */
+ for (i = index + 1; i < n_baseclasses; i++)
+ {
+ int boffset =
+ baseclass_offset (type, i, valaddr, address);
+ if (boffset)
+ return boffset;
+ }
+ /* Not found. */
+ return -1;
+ }
+
+ /* Baseclass is easily computed. */
+ return TYPE_BASECLASS_BITPOS (type, index) / 8;
+}