}
+/* Determine whether structure TYPE is a dynamic class. Cache the
+ result. */
+
+static int
+gnuv3_dynamic_class (struct type *type)
+{
+ int fieldnum, fieldelem;
+
+ if (TYPE_CPLUS_DYNAMIC (type))
+ return TYPE_CPLUS_DYNAMIC (type) == 1;
+
+ ALLOCATE_CPLUS_STRUCT_TYPE (type);
+
+ for (fieldnum = 0; fieldnum < TYPE_N_BASECLASSES (type); fieldnum++)
+ if (BASETYPE_VIA_VIRTUAL (type, fieldnum)
+ || gnuv3_dynamic_class (TYPE_FIELD_TYPE (type, fieldnum)))
+ {
+ TYPE_CPLUS_DYNAMIC (type) = 1;
+ return 1;
+ }
+
+ for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
+ for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
+ fieldelem++)
+ {
+ struct fn_field *f = TYPE_FN_FIELDLIST1 (type, fieldnum);
+
+ if (TYPE_FN_FIELD_VIRTUAL_P (f, fieldelem))
+ {
+ TYPE_CPLUS_DYNAMIC (type) = 1;
+ return 1;
+ }
+ }
+
+ TYPE_CPLUS_DYNAMIC (type) = -1;
+ return 0;
+}
+
+/* Find the vtable for a value of CONTAINER_TYPE located at
+ CONTAINER_ADDR. Return a value of the correct vtable type for this
+ architecture, or NULL if CONTAINER does not have a vtable. */
+
+static struct value *
+gnuv3_get_vtable (struct gdbarch *gdbarch,
+ struct type *container_type, CORE_ADDR container_addr)
+{
+ struct type *vtable_type = gdbarch_data (gdbarch,
+ vtable_type_gdbarch_data);
+ struct type *vtable_pointer_type;
+ struct value *vtable_pointer;
+ CORE_ADDR vtable_address;
+
+ /* If this type does not have a virtual table, don't read the first
+ field. */
+ if (!gnuv3_dynamic_class (check_typedef (container_type)))
+ return NULL;
+
+ /* We do not consult the debug information to find the virtual table.
+ The ABI specifies that it is always at offset zero in any class,
+ and debug information may not represent it.
+
+ We avoid using value_contents on principle, because the object might
+ be large. */
+
+ /* Find the type "pointer to virtual table". */
+ vtable_pointer_type = lookup_pointer_type (vtable_type);
+
+ /* Load it from the start of the class. */
+ vtable_pointer = value_at (vtable_pointer_type, container_addr);
+ vtable_address = value_as_address (vtable_pointer);
+
+ /* Correct it to point at the start of the virtual table, rather
+ than the address point. */
+ return value_at_lazy (vtable_type,
+ vtable_address - vtable_address_point_offset (gdbarch));
+}
+
+
static struct type *
gnuv3_rtti_type (struct value *value,
int *full_p, int *top_p, int *using_enc_p)
{
struct gdbarch *gdbarch;
- struct type *vtable_type;
struct type *values_type = check_typedef (value_type (value));
- CORE_ADDR vtable_address;
struct value *vtable;
struct minimal_symbol *vtable_symbol;
const char *vtable_symbol_name;
const char *class_name;
struct type *run_time_type;
- struct type *base_type;
LONGEST offset_to_top;
- struct type *values_type_vptr_basetype;
- int values_type_vptr_fieldno;
/* We only have RTTI for class objects. */
if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
/* Determine architecture. */
gdbarch = get_type_arch (values_type);
- vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
-
- /* If we can't find the virtual table pointer for values_type, we
- can't find the RTTI. */
- values_type_vptr_fieldno = get_vptr_fieldno (values_type,
- &values_type_vptr_basetype);
- if (values_type_vptr_fieldno == -1)
- return NULL;
if (using_enc_p)
*using_enc_p = 0;
- /* Fetch VALUE's virtual table pointer, and tweak it to point at
- an instance of our imaginary gdb_gnu_v3_abi_vtable structure. */
- base_type = check_typedef (values_type_vptr_basetype);
- if (values_type != base_type)
- {
- value = value_cast (base_type, value);
- if (using_enc_p)
- *using_enc_p = 1;
- }
- vtable_address
- = value_as_address (value_field (value, values_type_vptr_fieldno));
- vtable
- = value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset (gdbarch));
-
+ vtable = gnuv3_get_vtable (gdbarch, value_type (value),
+ value_as_address (value_addr (value)));
+ if (vtable == NULL)
+ return NULL;
+
/* Find the linker symbol for this vtable. */
vtable_symbol
= lookup_minimal_symbol_by_pc (value_address (vtable)
>= TYPE_LENGTH (run_time_type)));
if (top_p)
*top_p = - offset_to_top;
-
return run_time_type;
}
-/* Find the vtable for CONTAINER and return a value of the correct
- vtable type for this architecture. */
-
-static struct value *
-gnuv3_get_vtable (struct gdbarch *gdbarch, struct value *container)
-{
- struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
- struct type *vtable_pointer_type;
- struct value *vtable_pointer;
- CORE_ADDR vtable_pointer_address, vtable_address;
-
- /* We do not consult the debug information to find the virtual table.
- The ABI specifies that it is always at offset zero in any class,
- and debug information may not represent it. We won't issue an
- error if there's a class with virtual functions but no virtual table
- pointer, but something's already gone seriously wrong if that
- happens.
-
- We avoid using value_contents on principle, because the object might
- be large. */
-
- /* Find the type "pointer to virtual table". */
- vtable_pointer_type = lookup_pointer_type (vtable_type);
-
- /* Load it from the start of the class. */
- vtable_pointer_address = value_as_address (value_addr (container));
- vtable_pointer = value_at (vtable_pointer_type, vtable_pointer_address);
- vtable_address = value_as_address (vtable_pointer);
-
- /* Correct it to point at the start of the virtual table, rather
- than the address point. */
- return value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset (gdbarch));
-}
-
/* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual
function, of type FNTYPE. */
gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container,
struct type *fntype, int vtable_index)
{
- struct value *vtable = gnuv3_get_vtable (gdbarch, container);
- struct value *vfn;
+ struct value *vtable, *vfn;
+
+ /* Every class with virtual functions must have a vtable. */
+ vtable = gnuv3_get_vtable (gdbarch, value_type (container),
+ value_as_address (value_addr (container)));
+ gdb_assert (vtable != NULL);
/* Fetch the appropriate function pointer from the vtable. */
vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions),
CORE_ADDR address)
{
struct gdbarch *gdbarch;
- struct type *vtable_type;
struct type *ptr_type;
struct value *vtable;
- struct type *vbasetype;
struct value *vbase_array;
- CORE_ADDR vtable_address;
long int cur_base_offset, base_offset;
- int vbasetype_vptr_fieldno;
/* Determine architecture. */
gdbarch = get_type_arch (type);
- vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
/* If it isn't a virtual base, this is easy. The offset is in the
error (_("Misaligned vbase offset."));
cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type));
- /* We're now looking for the cur_base_offset'th entry (negative index)
- in the vcall_and_vbase_offsets array. We used to cast the object to
- its TYPE_VPTR_BASETYPE, and reference the vtable as TYPE_VPTR_FIELDNO;
- however, that cast can not be done without calling baseclass_offset again
- if the TYPE_VPTR_BASETYPE is a virtual base class, as described in the
- v3 C++ ABI Section 2.4.I.2.b. Fortunately the ABI guarantees that the
- vtable pointer will be located at the beginning of the object, so we can
- bypass the casting. Verify that the TYPE_VPTR_FIELDNO is in fact at the
- start of whichever baseclass it resides in, as a sanity measure - iff
- we have debugging information for that baseclass. */
-
- vbasetype = check_typedef (TYPE_VPTR_BASETYPE (type));
- vbasetype_vptr_fieldno = get_vptr_fieldno (vbasetype, NULL);
-
- if (vbasetype_vptr_fieldno >= 0
- && TYPE_FIELD_BITPOS (vbasetype, vbasetype_vptr_fieldno) != 0)
- error (_("Illegal vptr offset in class %s"),
- TYPE_NAME (vbasetype) ? TYPE_NAME (vbasetype) : "<unknown>");
-
- vtable_address = value_as_address (value_at_lazy (ptr_type, address));
- vtable
- = value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset (gdbarch));
+ vtable = gnuv3_get_vtable (gdbarch, type, address);
+ gdb_assert (vtable != NULL);
vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets);
base_offset = value_as_long (value_subscript (vbase_array, cur_base_offset));
return base_offset;
projects / external / binutils.git / commitdiff