[gdb/symtab] Factor out type::{alloc_fields,copy_fields}

After finding this code in buildsym_compunit::finish_block_internal:
...
              ftype->set_fields
                ((struct field *)
                 TYPE_ALLOC (ftype, nparams * sizeof (struct field)));
...
and fixing PR30810 by using TYPE_ZALLOC, I wondered if there were more
locations that needed fixing.

I decided to make things easier to spot by factoring out a new function
alloc_fields:
...
 /* Allocate the fields array of this type, with NFIELDS elements.  If INIT,
     zero-initialize the allocated memory.  */
  void
  type::alloc_fields (unsigned int nfields, bool init = true);
...
where:
- a regular use would be "alloc_fields (nfields)", and
- an exceptional use that needed no initialization would be
  "alloc_fields (nfields, false)".

Pretty soon I discovered that most of the latter cases are due to
initialization by memcpy, so I added two variants of copy_fields as well.

After this rewrite there are 8 uses of set_fields left:
...
gdb/coffread.c:	  type->set_fields (nullptr);
gdb/coffread.c:	  type->set_fields (nullptr);
gdb/coffread.c:	  type->set_fields (nullptr);
gdb/eval.c:  type->set_fields
gdb/gdbtypes.c:  type->set_fields (args);
gdb/gdbtypes.c:  t->set_fields (XRESIZEVEC (struct field, t->fields (),
gdb/dwarf2/read.c:      type->set_fields (new_fields);
gdb/dwarf2/read.c:	      sub_type->set_fields (sub_type->fields () + 1);
...

These fall into the following categories:
- set to nullptr (coffread.c),
- type not owned by objfile or gdbarch (eval.c), and
- modifying an existing fields array, like adding an element at the end or
  dropping an element at the start (the rest).

Tested on x86_64-linux.
This commit is contained in:
Tom de Vries 2023-08-31 09:37:44 +02:00
parent 0b8b932dce
commit 2774f2dad5
13 changed files with 146 additions and 186 deletions

View file

@ -7772,9 +7772,7 @@ ada_template_to_fixed_record_type_1 (struct type *type,
rtype = type_allocator (type).new_type ();
rtype->set_code (TYPE_CODE_STRUCT);
INIT_NONE_SPECIFIC (rtype);
rtype->set_num_fields (nfields);
rtype->set_fields
((struct field *) TYPE_ZALLOC (rtype, nfields * sizeof (struct field)));
rtype->alloc_fields (nfields);
rtype->set_name (ada_type_name (type));
rtype->set_is_fixed_instance (true);
@ -8024,14 +8022,8 @@ template_to_static_fixed_type (struct type *type0)
type0->set_target_type (type);
type->set_code (type0->code ());
INIT_NONE_SPECIFIC (type);
type->set_num_fields (nfields);
field *fields =
((struct field *)
TYPE_ALLOC (type, nfields * sizeof (struct field)));
memcpy (fields, type0->fields (),
sizeof (struct field) * nfields);
type->set_fields (fields);
type->copy_fields (type0);
type->set_name (ada_type_name (type0));
type->set_is_fixed_instance (true);
@ -8077,12 +8069,7 @@ to_record_with_fixed_variant_part (struct type *type, const gdb_byte *valaddr,
rtype = type_allocator (type).new_type ();
rtype->set_code (TYPE_CODE_STRUCT);
INIT_NONE_SPECIFIC (rtype);
rtype->set_num_fields (nfields);
field *fields =
(struct field *) TYPE_ALLOC (rtype, nfields * sizeof (struct field));
memcpy (fields, type->fields (), sizeof (struct field) * nfields);
rtype->set_fields (fields);
rtype->copy_fields (type);
rtype->set_name (ada_type_name (type));
rtype->set_is_fixed_instance (true);

View file

@ -757,10 +757,7 @@ amd_dbgapi_register_type_to_gdb_type (const amd_dbgapi_register_type &type,
.new_type (TYPE_CODE_ENUM, enum_type.bit_size (),
enum_type.name ().c_str ()));
gdb_type->set_num_fields (enum_type.size ());
gdb_type->set_fields
((struct field *) TYPE_ZALLOC (gdb_type, (sizeof (struct field)
* enum_type.size ())));
gdb_type->alloc_fields (enum_type.size ());
gdb_type->set_is_unsigned (true);
for (size_t i = 0; i < enum_type.size (); ++i)

View file

@ -264,10 +264,7 @@ buildsym_compunit::finish_block_internal
}
if (nparams > 0)
{
ftype->set_num_fields (nparams);
ftype->set_fields
((struct field *)
TYPE_ZALLOC (ftype, nparams * sizeof (struct field)));
ftype->alloc_fields (nparams);
iparams = 0;
/* Here we want to directly access the dictionary, because

View file

@ -1462,14 +1462,9 @@ patch_type (struct type *type, struct type *real_type)
{
struct type *target = type->target_type ();
struct type *real_target = real_type->target_type ();
int field_size = real_target->num_fields () * sizeof (struct field);
target->set_length (real_target->length ());
target->set_num_fields (real_target->num_fields ());
field *fields = (struct field *) TYPE_ALLOC (target, field_size);
memcpy (fields, real_target->fields (), field_size);
target->set_fields (fields);
target->copy_fields (real_target);
if (real_target->name ())
{
@ -2037,9 +2032,7 @@ coff_read_struct_type (int index, int length, int lastsym,
}
/* Now create the vector of fields, and record how big it is. */
type->set_num_fields (nfields);
type->set_fields
((struct field *) TYPE_ALLOC (type, sizeof (struct field) * nfields));
type->alloc_fields (nfields, false);
/* Copy the saved-up fields into the field vector. */
@ -2117,9 +2110,7 @@ coff_read_enum_type (int index, int length, int lastsym,
else /* Assume ints. */
type->set_length (gdbarch_int_bit (gdbarch) / TARGET_CHAR_BIT);
type->set_code (TYPE_CODE_ENUM);
type->set_num_fields (nsyms);
type->set_fields
((struct field *) TYPE_ALLOC (type, sizeof (struct field) * nsyms));
type->alloc_fields (nsyms, false);
/* Find the symbols for the values and put them into the type.
The symbols can be found in the symlist that we put them on

View file

@ -346,9 +346,7 @@ attach_fields_to_type (struct ctf_field_info *fip, struct type *type)
return;
/* Record the field count, allocate space for the array of fields. */
type->set_num_fields (nfields);
type->set_fields
((struct field *) TYPE_ZALLOC (type, sizeof (struct field) * nfields));
type->alloc_fields (nfields);
/* Copy the saved-up fields into the field vector. */
for (int i = 0; i < nfields; ++i)
@ -715,8 +713,7 @@ read_func_kind_type (struct ctf_context *ccp, ctf_id_t tid)
if (ctf_func_type_args (fp, tid, argc, argv.data ()) == CTF_ERR)
return nullptr;
type->set_fields
((struct field *) TYPE_ZALLOC (type, argc * sizeof (struct field)));
type->alloc_fields (argc);
struct type *void_type = builtin_type (of)->builtin_void;
/* If failed to find the argument type, fill it with void_type. */
for (int iparam = 0; iparam < argc; iparam++)

View file

@ -6054,11 +6054,9 @@ quirk_rust_enum (struct type *type, struct objfile *objfile)
/* Smash this type to be a structure type. We have to do this
because the type has already been recorded. */
type->set_code (TYPE_CODE_STRUCT);
type->set_num_fields (3);
/* Save the field we care about. */
struct field saved_field = type->field (0);
type->set_fields
((struct field *) TYPE_ZALLOC (type, 3 * sizeof (struct field)));
type->alloc_fields (3);
/* Put the discriminant at index 0. */
type->field (0).set_type (field_type);
@ -12059,9 +12057,7 @@ dwarf2_attach_fields_to_type (struct field_info *fip, struct type *type,
/* Record the field count, allocate space for the array of fields,
and create blank accessibility bitfields if necessary. */
type->set_num_fields (nfields);
type->set_fields
((struct field *) TYPE_ZALLOC (type, sizeof (struct field) * nfields));
type->alloc_fields (nfields);
if (fip->non_public_fields && cu->lang () != language_ada)
{
@ -12490,12 +12486,7 @@ rewrite_array_type (struct type *type)
updated. Either way we want to copy the type and update
everything. */
struct type *copy = copy_type (type);
int nfields = copy->num_fields ();
field *new_fields
= ((struct field *) TYPE_ZALLOC (copy,
nfields * sizeof (struct field)));
memcpy (new_fields, copy->fields (), nfields * sizeof (struct field));
copy->set_fields (new_fields);
copy->copy_fields (type);
if (new_target != nullptr)
copy->set_target_type (new_target);
@ -13260,14 +13251,7 @@ update_enumeration_type_from_children (struct die_info *die,
}
if (!fields.empty ())
{
type->set_num_fields (fields.size ());
type->set_fields
((struct field *)
TYPE_ALLOC (type, sizeof (struct field) * fields.size ()));
memcpy (type->fields (), fields.data (),
sizeof (struct field) * fields.size ());
}
type->copy_fields (fields);
else
flag_enum = 0;
@ -13636,12 +13620,7 @@ quirk_ada_thick_pointer (struct die_info *die, struct dwarf2_cu *cu,
struct type *bounds = alloc.new_type ();
bounds->set_code (TYPE_CODE_STRUCT);
bounds->set_num_fields (range_fields.size ());
bounds->set_fields
((struct field *) TYPE_ALLOC (bounds, (bounds->num_fields ()
* sizeof (struct field))));
memcpy (bounds->fields (), range_fields.data (),
bounds->num_fields () * sizeof (struct field));
bounds->copy_fields (range_fields);
int last_fieldno = range_fields.size () - 1;
int bounds_size = (bounds->field (last_fieldno).loc_bitpos () / 8
@ -13664,10 +13643,7 @@ quirk_ada_thick_pointer (struct die_info *die, struct dwarf2_cu *cu,
struct type *result = type_allocator (objfile).new_type ();
result->set_code (TYPE_CODE_STRUCT);
result->set_num_fields (2);
result->set_fields
((struct field *) TYPE_ZALLOC (result, (result->num_fields ()
* sizeof (struct field))));
result->alloc_fields (2);
/* The names are chosen to coincide with what the compiler does with
-fgnat-encodings=all, which the Ada code in gdb already
@ -14709,9 +14685,7 @@ read_subroutine_type (struct die_info *die, struct dwarf2_cu *cu)
}
/* Allocate storage for parameters and fill them in. */
ftype->set_num_fields (nparams);
ftype->set_fields
((struct field *) TYPE_ZALLOC (ftype, nparams * sizeof (struct field)));
ftype->alloc_fields (nparams);
/* TYPE_FIELD_TYPE must never be NULL. Pre-fill the array to ensure it
even if we error out during the parameters reading below. */

View file

@ -597,9 +597,7 @@ lookup_function_type_with_arguments (struct type *type,
fn->set_is_prototyped (true);
}
fn->set_num_fields (nparams);
fn->set_fields
((struct field *) TYPE_ZALLOC (fn, nparams * sizeof (struct field)));
fn->alloc_fields (nparams);
for (i = 0; i < nparams; ++i)
fn->field (i).set_type (param_types[i]);
@ -1356,9 +1354,7 @@ create_array_type_with_stride (type_allocator &alloc,
result_type->set_code (TYPE_CODE_ARRAY);
result_type->set_target_type (element_type);
result_type->set_num_fields (1);
result_type->set_fields
((struct field *) TYPE_ZALLOC (result_type, sizeof (struct field)));
result_type->alloc_fields (1);
result_type->set_index_type (range_type);
if (byte_stride_prop != NULL)
result_type->add_dyn_prop (DYN_PROP_BYTE_STRIDE, *byte_stride_prop);
@ -1442,9 +1438,7 @@ create_set_type (type_allocator &alloc, struct type *domain_type)
struct type *result_type = alloc.new_type ();
result_type->set_code (TYPE_CODE_SET);
result_type->set_num_fields (1);
result_type->set_fields
((struct field *) TYPE_ZALLOC (result_type, sizeof (struct field)));
result_type->alloc_fields (1);
if (!domain_type->is_stub ())
{
@ -2452,13 +2446,7 @@ resolve_dynamic_union (struct type *type,
gdb_assert (type->code () == TYPE_CODE_UNION);
resolved_type = copy_type (type);
resolved_type->set_fields
((struct field *)
TYPE_ALLOC (resolved_type,
resolved_type->num_fields () * sizeof (struct field)));
memcpy (resolved_type->fields (),
type->fields (),
resolved_type->num_fields () * sizeof (struct field));
resolved_type->copy_fields (type);
for (i = 0; i < resolved_type->num_fields (); ++i)
{
struct type *t;
@ -2618,12 +2606,10 @@ compute_variant_fields (struct type *type,
for (const auto &part : parts)
compute_variant_fields_inner (type, addr_stack, part, flags);
resolved_type->set_num_fields
(std::count (flags.begin (), flags.end (), true));
resolved_type->set_fields
((struct field *)
TYPE_ALLOC (resolved_type,
resolved_type->num_fields () * sizeof (struct field)));
unsigned int nfields = std::count (flags.begin (), flags.end (), true);
/* No need to zero-initialize the newly allocated fields, they'll be
initialized by the copy in the loop below. */
resolved_type->alloc_fields (nfields, false);
int out = 0;
for (int i = 0; i < type->num_fields (); ++i)
@ -2664,14 +2650,7 @@ resolve_dynamic_struct (struct type *type,
}
else
{
resolved_type->set_fields
((struct field *)
TYPE_ALLOC (resolved_type,
resolved_type->num_fields () * sizeof (struct field)));
if (type->num_fields () > 0)
memcpy (resolved_type->fields (),
type->fields (),
resolved_type->num_fields () * sizeof (struct field));
resolved_type->copy_fields (type);
}
for (i = 0; i < resolved_type->num_fields (); ++i)
@ -5556,9 +5535,7 @@ copy_type_recursive (struct type *type, htab_t copied_types)
int i, nfields;
nfields = type->num_fields ();
new_type->set_fields
((struct field *)
TYPE_ZALLOC (new_type, nfields * sizeof (struct field)));
new_type->alloc_fields (type->num_fields ());
for (i = 0; i < nfields; i++)
{
@ -5703,10 +5680,9 @@ arch_flags_type (struct gdbarch *gdbarch, const char *name, int bit)
type = type_allocator (gdbarch).new_type (TYPE_CODE_FLAGS, bit, name);
type->set_is_unsigned (true);
type->set_num_fields (0);
/* Pre-allocate enough space assuming every field is one bit. */
type->set_fields
((struct field *) TYPE_ZALLOC (type, bit * sizeof (struct field)));
type->alloc_fields (bit);
type->set_num_fields (0);
return type;
}
@ -5912,6 +5888,55 @@ type::fixed_point_scaling_factor ()
return type->fixed_point_info ().scaling_factor;
}
/* See gdbtypes.h. */
void
type::alloc_fields (unsigned int nfields, bool init)
{
this->set_num_fields (nfields);
if (nfields == 0)
{
this->main_type->flds_bnds.fields = nullptr;
return;
}
size_t size = nfields * sizeof (*this->fields ());
struct field *fields
= (struct field *) (init
? TYPE_ZALLOC (this, size)
: TYPE_ALLOC (this, size));
this->main_type->flds_bnds.fields = fields;
}
/* See gdbtypes.h. */
void
type::copy_fields (struct type *src)
{
unsigned int nfields = src->num_fields ();
alloc_fields (nfields, false);
if (nfields == 0)
return;
size_t size = nfields * sizeof (*this->fields ());
memcpy (this->fields (), src->fields (), size);
}
/* See gdbtypes.h. */
void
type::copy_fields (std::vector<struct field> &src)
{
unsigned int nfields = src.size ();
alloc_fields (nfields, false);
if (nfields == 0)
return;
size_t size = nfields * sizeof (*this->fields ());
memcpy (this->fields (), src.data (), size);
}
static const registry<gdbarch>::key<struct builtin_type> gdbtypes_data;

View file

@ -992,6 +992,14 @@ struct type
this->main_type->flds_bnds.fields = fields;
}
/* Allocate the fields array of this type, with NFIELDS elements. If INIT,
zero-initialize the allocated memory. */
void alloc_fields (unsigned int nfields, bool init = true);
/* Allocate the fields array of this type, and copy the fields from SRC. */
void copy_fields (struct type *src);
void copy_fields (std::vector<struct field> &src);
type *index_type () const
{
return this->field (0).type ();

View file

@ -113,7 +113,6 @@ static struct type *
get_gdb_vtable_type (struct gdbarch *arch)
{
struct type *t;
struct field *field_list, *field;
int offset;
struct type *result = vtable_type_gdbarch_data.get (arch);
@ -131,50 +130,56 @@ get_gdb_vtable_type (struct gdbarch *arch)
struct type *ptrdiff_type
= init_integer_type (alloc, gdbarch_ptr_bit (arch), 0, "ptrdiff_t");
t = alloc.new_type (TYPE_CODE_STRUCT, 0, nullptr);
/* We assume no padding is necessary, since GDB doesn't know
anything about alignment at the moment. If this assumption bites
us, we should add a gdbarch method which, given a type, returns
the alignment that type requires, and then use that here. */
/* Build the field list. */
field_list = XCNEWVEC (struct field, 4);
field = &field_list[0];
t->alloc_fields (4);
offset = 0;
/* ptrdiff_t vcall_and_vbase_offsets[0]; */
field->set_name ("vcall_and_vbase_offsets");
field->set_type (lookup_array_range_type (ptrdiff_type, 0, -1));
field->set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field->type ()->length ();
field++;
{
struct field &field0 = t->field (0);
field0.set_name ("vcall_and_vbase_offsets");
field0.set_type (lookup_array_range_type (ptrdiff_type, 0, -1));
field0.set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field0.type ()->length ();
}
/* ptrdiff_t offset_to_top; */
field->set_name ("offset_to_top");
field->set_type (ptrdiff_type);
field->set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field->type ()->length ();
field++;
{
struct field &field1 = t->field (1);
field1.set_name ("offset_to_top");
field1.set_type (ptrdiff_type);
field1.set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field1.type ()->length ();
}
/* void *type_info; */
field->set_name ("type_info");
field->set_type (void_ptr_type);
field->set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field->type ()->length ();
field++;
{
struct field &field2 = t->field (2);
field2.set_name ("type_info");
field2.set_type (void_ptr_type);
field2.set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field2.type ()->length ();
}
/* void (*virtual_functions[0]) (); */
field->set_name ("virtual_functions");
field->set_type (lookup_array_range_type (ptr_to_void_fn_type, 0, -1));
field->set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field->type ()->length ();
field++;
{
struct field &field3 = t->field (3);
field3.set_name ("virtual_functions");
field3.set_type (lookup_array_range_type (ptr_to_void_fn_type, 0, -1));
field3.set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field3.type ()->length ();
}
/* We assumed in the allocation above that there were four fields. */
gdb_assert (field == (field_list + 4));
t->set_length (offset);
t = alloc.new_type (TYPE_CODE_STRUCT, offset * TARGET_CHAR_BIT, NULL);
t->set_num_fields (field - field_list);
t->set_fields (field_list);
t->set_name ("gdb_gnu_v3_abi_vtable");
INIT_CPLUS_SPECIFIC (t);
@ -1026,7 +1031,6 @@ static struct type *
build_std_type_info_type (struct gdbarch *arch)
{
struct type *t;
struct field *field_list, *field;
int offset;
struct type *void_ptr_type
= builtin_type (arch)->builtin_data_ptr;
@ -1035,30 +1039,32 @@ build_std_type_info_type (struct gdbarch *arch)
struct type *char_ptr_type
= make_pointer_type (make_cv_type (1, 0, char_type, NULL), NULL);
field_list = XCNEWVEC (struct field, 2);
field = &field_list[0];
t = type_allocator (arch).new_type (TYPE_CODE_STRUCT, 0, nullptr);
t->alloc_fields (2);
offset = 0;
/* The vtable. */
field->set_name ("_vptr.type_info");
field->set_type (void_ptr_type);
field->set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field->type ()->length ();
field++;
{
struct field &field0 = t->field (0);
field0.set_name ("_vptr.type_info");
field0.set_type (void_ptr_type);
field0.set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field0.type ()->length ();
}
/* The name. */
field->set_name ("__name");
field->set_type (char_ptr_type);
field->set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field->type ()->length ();
field++;
{
struct field &field1 = t->field (1);
field1.set_name ("__name");
field1.set_type (char_ptr_type);
field1.set_loc_bitpos (offset * TARGET_CHAR_BIT);
offset += field1.type ()->length ();
}
gdb_assert (field == (field_list + 2));
t->set_length (offset);
t = type_allocator (arch).new_type (TYPE_CODE_STRUCT,
offset * TARGET_CHAR_BIT, nullptr);
t->set_num_fields (field - field_list);
t->set_fields (field_list);
t->set_name ("gdb_gnu_v3_type_info");
INIT_CPLUS_SPECIFIC (t);

View file

@ -1034,9 +1034,7 @@ parse_symbol (SYMR *sh, union aux_ext *ax, char *ext_sh, int bigend,
t->set_code (type_code);
t->set_length (sh->value);
t->set_num_fields (nfields);
f = ((struct field *) TYPE_ALLOC (t, nfields * sizeof (struct field)));
t->set_fields (f);
t->alloc_fields (nfields, false);
if (type_code == TYPE_CODE_ENUM)
{
@ -1197,10 +1195,7 @@ parse_symbol (SYMR *sh, union aux_ext *ax, char *ext_sh, int bigend,
if (nparams > 0)
{
ftype->set_num_fields (nparams);
ftype->set_fields
((struct field *)
TYPE_ALLOC (ftype, nparams * sizeof (struct field)));
ftype->alloc_fields (nparams, false);
iparams = 0;
for (struct symbol *sym : block_iterator_range (cblock))

View file

@ -950,9 +950,7 @@ rust_composite_type (struct type *original,
result->set_code (TYPE_CODE_STRUCT);
result->set_name (name);
result->set_num_fields (nfields);
result->set_fields
((struct field *) TYPE_ZALLOC (result, nfields * sizeof (struct field)));
result->alloc_fields (nfields);
i = 0;
bitpos = 0;

View file

@ -982,9 +982,7 @@ define_symbol (CORE_ADDR valu, const char *string, int desc, int type,
}
/* Allocate parameter information fields and fill them in. */
ftype->set_fields
((struct field *)
TYPE_ALLOC (ftype, nsemi * sizeof (struct field)));
ftype->alloc_fields (nsemi, false);
while (*p++ == ';')
{
struct type *ptype;
@ -1826,10 +1824,7 @@ again:
&& arg_types->type->code () == TYPE_CODE_VOID)
num_args = 0;
func_type->set_fields
((struct field *) TYPE_ALLOC (func_type,
num_args * sizeof (struct field)));
memset (func_type->fields (), 0, num_args * sizeof (struct field));
func_type->alloc_fields (num_args);
{
int i;
struct type_list *t;
@ -3295,11 +3290,7 @@ attach_fields_to_type (struct stab_field_info *fip, struct type *type,
non-public fields. Record the field count, allocate space for the
array of fields, and create blank visibility bitfields if necessary. */
type->set_num_fields (nfields);
type->set_fields
((struct field *)
TYPE_ALLOC (type, sizeof (struct field) * nfields));
memset (type->fields (), 0, sizeof (struct field) * nfields);
type->alloc_fields (nfields);
if (non_public_fields)
{
@ -3644,11 +3635,7 @@ read_enum_type (const char **pp, struct type *type,
type->set_is_stub (false);
if (unsigned_enum)
type->set_is_unsigned (true);
type->set_num_fields (nsyms);
type->set_fields
((struct field *)
TYPE_ALLOC (type, sizeof (struct field) * nsyms));
memset (type->fields (), 0, sizeof (struct field) * nsyms);
type->alloc_fields (nsyms);
/* Find the symbols for the values and put them into the type.
The symbols can be found in the symlist that we put them on

View file

@ -745,9 +745,7 @@ create_enum (struct gdbarch *gdbarch, int bit, const char *name,
int i;
type = type_allocator (gdbarch).new_type (TYPE_CODE_ENUM, bit, name);
type->set_num_fields (count);
type->set_fields
((struct field *) TYPE_ZALLOC (type, sizeof (struct field) * count));
type->alloc_fields (count);
type->set_is_unsigned (true);
for (i = 0; i < count; i++)