-/* ARG is a pointer to an object we know to be at least
- a DTYPE. BTYPE is the most derived basetype that has
- already been searched (and need not be searched again).
- After looking at the vtables between BTYPE and DTYPE,
- return the most derived type we find. The caller must
- be satisfied when the return value == DTYPE.
-
- FIXME-tiemann: should work with dossier entries as well.
- NOTICE - djb: I see no good reason at all to keep this function now that
- we have RTTI support. It's used in literally one place, and it's
- hard to keep this function up to date when it's purpose is served
- by value_rtti_type efficiently.
- Consider it gone for 5.1. */
-
-static value_ptr
-value_headof (value_ptr in_arg, struct type *btype, struct type *dtype)
-{
- /* First collect the vtables we must look at for this object. */
- value_ptr arg, vtbl;
- struct symbol *sym;
- char *demangled_name;
- struct minimal_symbol *msymbol;
-
- btype = TYPE_VPTR_BASETYPE (dtype);
- CHECK_TYPEDEF (btype);
- arg = in_arg;
- if (btype != dtype)
- arg = value_cast (lookup_pointer_type (btype), arg);
- if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF)
- {
- /*
- * Copy the value, but change the type from (T&) to (T*).
- * We keep the same location information, which is efficient,
- * and allows &(&X) to get the location containing the reference.
- */
- arg = value_copy (arg);
- VALUE_TYPE (arg) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg)));
- }
- if (VALUE_ADDRESS(value_field (value_ind(arg), TYPE_VPTR_FIELDNO (btype)))==0)
- return arg;
-
- vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype)));
- /* Turn vtable into typeinfo function */
- VALUE_OFFSET(vtbl)+=4;
-
- msymbol = lookup_minimal_symbol_by_pc ( value_as_pointer(value_ind(vtbl)) );
- if (msymbol == NULL
- || (demangled_name = SYMBOL_NAME (msymbol)) == NULL)
- {
- /* If we expected to find a vtable, but did not, let the user
- know that we aren't happy, but don't throw an error.
- FIXME: there has to be a better way to do this. */
- struct type *error_type = (struct type *) xmalloc (sizeof (struct type));
- memcpy (error_type, VALUE_TYPE (in_arg), sizeof (struct type));
- TYPE_NAME (error_type) = savestring ("suspicious *", sizeof ("suspicious *"));
- VALUE_TYPE (in_arg) = error_type;
- return in_arg;
- }
- demangled_name = cplus_demangle(demangled_name,DMGL_ANSI);
- *(strchr (demangled_name, ' ')) = '\0';
-
- sym = lookup_symbol (demangled_name, 0, VAR_NAMESPACE, 0, 0);
- if (sym == NULL)
- error ("could not find type declaration for `%s'", demangled_name);
-
- arg = in_arg;
- VALUE_TYPE (arg) = lookup_pointer_type (SYMBOL_TYPE (sym));
- return arg;
-}
-
-/* ARG is a pointer object of type TYPE. If TYPE has virtual
- function tables, probe ARG's tables (including the vtables
- of its baseclasses) to figure out the most derived type that ARG
- could actually be a pointer to. */
-
-value_ptr
-value_from_vtable_info (value_ptr arg, struct type *type)
-{
- /* Take care of preliminaries. */
- if (TYPE_VPTR_FIELDNO (type) < 0)
- fill_in_vptr_fieldno (type);
- if (TYPE_VPTR_FIELDNO (type) < 0)
- return 0;
-
- return value_headof (arg, 0, type);
-}
-
-/* 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
- && STREQ (TYPE_NAME (basetype),
- TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))))
- 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
-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. */
- register int i, len = TYPE_NFIELDS (type);
- register 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;
-}