+/* Locate a virtual method in DOMAIN or its non-virtual base classes
+ which has virtual table index VOFFSET. The method has an associated
+ "this" adjustment of ADJUSTMENT bytes. */
+
+static const char *
+gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset,
+ LONGEST adjustment)
+{
+ int i;
+
+ /* Search this class first. */
+ if (adjustment == 0)
+ {
+ int len;
+
+ len = TYPE_NFN_FIELDS (domain);
+ for (i = 0; i < len; i++)
+ {
+ int len2, j;
+ struct fn_field *f;
+
+ f = TYPE_FN_FIELDLIST1 (domain, i);
+ len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);
+
+ check_stub_method_group (domain, i);
+ for (j = 0; j < len2; j++)
+ if (TYPE_FN_FIELD_VOFFSET (f, j) == voffset)
+ return TYPE_FN_FIELD_PHYSNAME (f, j);
+ }
+ }
+
+ /* Next search non-virtual bases. If it's in a virtual base,
+ we're out of luck. */
+ for (i = 0; i < TYPE_N_BASECLASSES (domain); i++)
+ {
+ int pos;
+ struct type *basetype;
+
+ if (BASETYPE_VIA_VIRTUAL (domain, i))
+ continue;
+
+ pos = TYPE_BASECLASS_BITPOS (domain, i) / 8;
+ basetype = TYPE_FIELD_TYPE (domain, i);
+ /* Recurse with a modified adjustment. We don't need to adjust
+ voffset. */
+ if (adjustment >= pos && adjustment < pos + TYPE_LENGTH (basetype))
+ return gnuv3_find_method_in (basetype, voffset, adjustment - pos);
+ }
+
+ return NULL;
+}
+
+/* Decode GNU v3 method pointer. */
+
+static int
+gnuv3_decode_method_ptr (struct gdbarch *gdbarch,
+ const gdb_byte *contents,
+ CORE_ADDR *value_p,
+ LONGEST *adjustment_p)
+{
+ struct type *funcptr_type = builtin_type (gdbarch)->builtin_func_ptr;
+ struct type *offset_type = vtable_ptrdiff_type (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ CORE_ADDR ptr_value;
+ LONGEST voffset, adjustment;
+ int vbit;
+
+ /* Extract the pointer to member. The first element is either a pointer
+ or a vtable offset. For pointers, we need to use extract_typed_address
+ to allow the back-end to convert the pointer to a GDB address -- but
+ vtable offsets we must handle as integers. At this point, we do not
+ yet know which case we have, so we extract the value under both
+ interpretations and choose the right one later on. */
+ ptr_value = extract_typed_address (contents, funcptr_type);
+ voffset = extract_signed_integer (contents,
+ TYPE_LENGTH (funcptr_type), byte_order);
+ contents += TYPE_LENGTH (funcptr_type);
+ adjustment = extract_signed_integer (contents,
+ TYPE_LENGTH (offset_type), byte_order);
+
+ if (!gdbarch_vbit_in_delta (gdbarch))
+ {
+ vbit = voffset & 1;
+ voffset = voffset ^ vbit;
+ }
+ else
+ {
+ vbit = adjustment & 1;
+ adjustment = adjustment >> 1;
+ }
+
+ *value_p = vbit? voffset : ptr_value;
+ *adjustment_p = adjustment;
+ return vbit;
+}
+
+/* GNU v3 implementation of cplus_print_method_ptr. */
+
+static void
+gnuv3_print_method_ptr (const gdb_byte *contents,
+ struct type *type,
+ struct ui_file *stream)
+{
+ struct type *domain = TYPE_DOMAIN_TYPE (type);
+ struct gdbarch *gdbarch = get_type_arch (domain);
+ CORE_ADDR ptr_value;
+ LONGEST adjustment;
+ int vbit;
+
+ /* Extract the pointer to member. */
+ vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
+
+ /* Check for NULL. */
+ if (ptr_value == 0 && vbit == 0)
+ {
+ fprintf_filtered (stream, "NULL");
+ return;
+ }
+
+ /* Search for a virtual method. */
+ if (vbit)
+ {
+ CORE_ADDR voffset;
+ const char *physname;
+
+ /* It's a virtual table offset, maybe in this class. Search
+ for a field with the correct vtable offset. First convert it
+ to an index, as used in TYPE_FN_FIELD_VOFFSET. */
+ voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
+
+ physname = gnuv3_find_method_in (domain, voffset, adjustment);
+
+ /* If we found a method, print that. We don't bother to disambiguate
+ possible paths to the method based on the adjustment. */
+ if (physname)
+ {
+ char *demangled_name = cplus_demangle (physname,
+ DMGL_ANSI | DMGL_PARAMS);
+
+ fprintf_filtered (stream, "&virtual ");
+ if (demangled_name == NULL)
+ fputs_filtered (physname, stream);
+ else
+ {
+ fputs_filtered (demangled_name, stream);
+ xfree (demangled_name);
+ }
+ return;
+ }
+ }
+ else if (ptr_value != 0)
+ {
+ /* Found a non-virtual function: print out the type. */
+ fputs_filtered ("(", stream);
+ c_print_type (type, "", stream, -1, 0);
+ fputs_filtered (") ", stream);
+ }
+
+ /* We didn't find it; print the raw data. */
+ if (vbit)
+ {
+ fprintf_filtered (stream, "&virtual table offset ");
+ print_longest (stream, 'd', 1, ptr_value);
+ }
+ else
+ print_address_demangle (gdbarch, ptr_value, stream, demangle);
+
+ if (adjustment)
+ {
+ fprintf_filtered (stream, ", this adjustment ");
+ print_longest (stream, 'd', 1, adjustment);
+ }
+}
+
+/* GNU v3 implementation of cplus_method_ptr_size. */
+
+static int
+gnuv3_method_ptr_size (struct type *type)
+{
+ struct gdbarch *gdbarch = get_type_arch (type);
+
+ return 2 * TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
+}
+
+/* GNU v3 implementation of cplus_make_method_ptr. */
+
+static void
+gnuv3_make_method_ptr (struct type *type, gdb_byte *contents,
+ CORE_ADDR value, int is_virtual)
+{
+ struct gdbarch *gdbarch = get_type_arch (type);
+ int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ /* FIXME drow/2006-12-24: The adjustment of "this" is currently
+ always zero, since the method pointer is of the correct type.
+ But if the method pointer came from a base class, this is
+ incorrect - it should be the offset to the base. The best
+ fix might be to create the pointer to member pointing at the
+ base class and cast it to the derived class, but that requires
+ support for adjusting pointers to members when casting them -
+ not currently supported by GDB. */
+
+ if (!gdbarch_vbit_in_delta (gdbarch))
+ {
+ store_unsigned_integer (contents, size, byte_order, value | is_virtual);
+ store_unsigned_integer (contents + size, size, byte_order, 0);
+ }
+ else
+ {
+ store_unsigned_integer (contents, size, byte_order, value);
+ store_unsigned_integer (contents + size, size, byte_order, is_virtual);
+ }
+}
+
+/* GNU v3 implementation of cplus_method_ptr_to_value. */
+
+static struct value *
+gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr)
+{
+ struct gdbarch *gdbarch;
+ const gdb_byte *contents = value_contents (method_ptr);
+ CORE_ADDR ptr_value;
+ struct type *domain_type, *final_type, *method_type;
+ LONGEST adjustment;
+ int vbit;
+
+ domain_type = TYPE_DOMAIN_TYPE (check_typedef (value_type (method_ptr)));
+ final_type = lookup_pointer_type (domain_type);
+
+ method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr)));
+
+ /* Extract the pointer to member. */
+ gdbarch = get_type_arch (domain_type);
+ vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
+
+ /* First convert THIS to match the containing type of the pointer to
+ member. This cast may adjust the value of THIS. */
+ *this_p = value_cast (final_type, *this_p);
+
+ /* Then apply whatever adjustment is necessary. This creates a somewhat
+ strange pointer: it claims to have type FINAL_TYPE, but in fact it
+ might not be a valid FINAL_TYPE. For instance, it might be a
+ base class of FINAL_TYPE. And if it's not the primary base class,
+ then printing it out as a FINAL_TYPE object would produce some pretty
+ garbage.
+
+ But we don't really know the type of the first argument in
+ METHOD_TYPE either, which is why this happens. We can't
+ dereference this later as a FINAL_TYPE, but once we arrive in the
+ called method we'll have debugging information for the type of
+ "this" - and that'll match the value we produce here.
+
+ You can provoke this case by casting a Base::* to a Derived::*, for
+ instance. */
+ *this_p = value_cast (builtin_type (gdbarch)->builtin_data_ptr, *this_p);
+ *this_p = value_ptradd (*this_p, adjustment);
+ *this_p = value_cast (final_type, *this_p);
+
+ if (vbit)
+ {
+ LONGEST voffset;
+
+ voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
+ return gnuv3_get_virtual_fn (gdbarch, value_ind (*this_p),
+ method_type, voffset);
+ }
+ else
+ return value_from_pointer (lookup_pointer_type (method_type), ptr_value);
+}
+
+/* Determine if we are currently in a C++ thunk. If so, get the address
+ of the routine we are thunking to and continue to there instead. */
+
+static CORE_ADDR
+gnuv3_skip_trampoline (struct frame_info *frame, CORE_ADDR stop_pc)
+{
+ CORE_ADDR real_stop_pc, method_stop_pc;
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct minimal_symbol *thunk_sym, *fn_sym;
+ struct obj_section *section;
+ char *thunk_name, *fn_name;
+
+ real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
+ if (real_stop_pc == 0)
+ real_stop_pc = stop_pc;
+
+ /* Find the linker symbol for this potential thunk. */
+ thunk_sym = lookup_minimal_symbol_by_pc (real_stop_pc);
+ section = find_pc_section (real_stop_pc);
+ if (thunk_sym == NULL || section == NULL)
+ return 0;
+
+ /* The symbol's demangled name should be something like "virtual
+ thunk to FUNCTION", where FUNCTION is the name of the function
+ being thunked to. */
+ thunk_name = SYMBOL_DEMANGLED_NAME (thunk_sym);
+ if (thunk_name == NULL || strstr (thunk_name, " thunk to ") == NULL)
+ return 0;
+
+ fn_name = strstr (thunk_name, " thunk to ") + strlen (" thunk to ");
+ fn_sym = lookup_minimal_symbol (fn_name, NULL, section->objfile);
+ if (fn_sym == NULL)
+ return 0;
+
+ method_stop_pc = SYMBOL_VALUE_ADDRESS (fn_sym);
+ real_stop_pc = gdbarch_skip_trampoline_code
+ (gdbarch, frame, method_stop_pc);
+ if (real_stop_pc == 0)
+ real_stop_pc = method_stop_pc;
+
+ return real_stop_pc;
+}
+
+/* Return nonzero if a type should be passed by reference.
+
+ The rule in the v3 ABI document comes from section 3.1.1. If the
+ type has a non-trivial copy constructor or destructor, then the
+ caller must make a copy (by calling the copy constructor if there
+ is one or perform the copy itself otherwise), pass the address of
+ the copy, and then destroy the temporary (if necessary).
+
+ For return values with non-trivial copy constructors or
+ destructors, space will be allocated in the caller, and a pointer
+ will be passed as the first argument (preceding "this").
+
+ We don't have a bulletproof mechanism for determining whether a
+ constructor or destructor is trivial. For GCC and DWARF2 debug
+ information, we can check the artificial flag.
+
+ We don't do anything with the constructors or destructors,
+ but we have to get the argument passing right anyway. */
+static int
+gnuv3_pass_by_reference (struct type *type)
+{
+ int fieldnum, fieldelem;
+
+ CHECK_TYPEDEF (type);
+
+ /* We're only interested in things that can have methods. */
+ if (TYPE_CODE (type) != TYPE_CODE_STRUCT
+ && TYPE_CODE (type) != TYPE_CODE_CLASS
+ && TYPE_CODE (type) != TYPE_CODE_UNION)
+ return 0;
+
+ for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
+ for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
+ fieldelem++)
+ {
+ struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum);
+ char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum);
+ struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem);
+
+ /* If this function is marked as artificial, it is compiler-generated,
+ and we assume it is trivial. */
+ if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem))
+ continue;
+
+ /* If we've found a destructor, we must pass this by reference. */
+ if (name[0] == '~')
+ return 1;
+
+ /* If the mangled name of this method doesn't indicate that it
+ is a constructor, we're not interested.
+
+ FIXME drow/2007-09-23: We could do this using the name of
+ the method and the name of the class instead of dealing
+ with the mangled name. We don't have a convenient function
+ to strip off both leading scope qualifiers and trailing
+ template arguments yet. */
+ if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem)))
+ continue;
+
+ /* If this method takes two arguments, and the second argument is
+ a reference to this class, then it is a copy constructor. */
+ if (TYPE_NFIELDS (fieldtype) == 2
+ && TYPE_CODE (TYPE_FIELD_TYPE (fieldtype, 1)) == TYPE_CODE_REF
+ && check_typedef (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (fieldtype,
+ 1))) == type)
+ return 1;
+ }
+
+ /* Even if all the constructors and destructors were artificial, one
+ of them may have invoked a non-artificial constructor or
+ destructor in a base class. If any base class needs to be passed
+ by reference, so does this class. Similarly for members, which
+ are constructed whenever this class is. We do not need to worry
+ about recursive loops here, since we are only looking at members
+ of complete class type. Also ignore any static members. */
+ for (fieldnum = 0; fieldnum < TYPE_NFIELDS (type); fieldnum++)
+ if (! field_is_static (&TYPE_FIELD (type, fieldnum))
+ && gnuv3_pass_by_reference (TYPE_FIELD_TYPE (type, fieldnum)))
+ return 1;
+
+ return 0;
+}
+