* gdbtypes.h (struct builtin_type): Add internal_fn member.

* gdbtypes.c (gdbtypes_post_init): Initialize it.
	* value.c (internal_fn_type): Remove.
	(_initialize_values): Do not initialize it.

	* value.c (struct internalvar): Add enum internalvar_kind type and
	kind member.  Restructure union internalvar_data type.  Remove type,
	canonical, and make_value members.
	(init_if_undefined_command): Update for data structure changes.
	(create_internalvar): Likewise.
	(create_internalvar_type_lazy): Likewise.
	(get_internalvar_integer): Likewise.
	(get_internalvar_function): Likewise.
	(set_internalvar_component): Likewise.
	(set_internalvar): Likewise.
	(set_internalvar_integer): Likewise.
	(set_internalvar_function): Likewise.
	(clear_internalvar): Likewise.
	(add_internal_function): Likewise.
	(preserve_one_internalvar): New function.
	(preserve_values): Call it.

	* value.h (value_of_internalvar): Add GDBARCH parameter.
	(internalvar_make_value): Likewise.
	* value.c (value_of_internalvar): Add GDBARCH parameter.  Pass it to
	make_value callback.  Use it to generate per-architecture result value
	types for internal variables with no pre-defined type.  Update for data
	structure changes.
	(show_convenience): Pass architecture to value_of_internalvar.
	* eval.c (evaluate_subexp_standard): Likewise.
	* infrun.c (siginfo_make_value): Add GDBARCH parameter.  Use it
	instead of current frame architecture.  Return per-architecture type.

	* value.h (set_internalvar_string): Add prototype.
	* value.c (set_internalvar_string): New function.
	* tracepoint.c (set_traceframe_context): Use it.
This commit is contained in:
Ulrich Weigand 2009-07-02 12:11:19 +00:00
parent 0daa2b63cc
commit 78267919d6
8 changed files with 278 additions and 175 deletions

View File

@ -1,3 +1,42 @@
2009-07-02 Ulrich Weigand <uweigand@de.ibm.com>
* gdbtypes.h (struct builtin_type): Add internal_fn member.
* gdbtypes.c (gdbtypes_post_init): Initialize it.
* value.c (internal_fn_type): Remove.
(_initialize_values): Do not initialize it.
* value.c (struct internalvar): Add enum internalvar_kind type and
kind member. Restructure union internalvar_data type. Remove type,
canonical, and make_value members.
(init_if_undefined_command): Update for data structure changes.
(create_internalvar): Likewise.
(create_internalvar_type_lazy): Likewise.
(get_internalvar_integer): Likewise.
(get_internalvar_function): Likewise.
(set_internalvar_component): Likewise.
(set_internalvar): Likewise.
(set_internalvar_integer): Likewise.
(set_internalvar_function): Likewise.
(clear_internalvar): Likewise.
(add_internal_function): Likewise.
(preserve_one_internalvar): New function.
(preserve_values): Call it.
* value.h (value_of_internalvar): Add GDBARCH parameter.
(internalvar_make_value): Likewise.
* value.c (value_of_internalvar): Add GDBARCH parameter. Pass it to
make_value callback. Use it to generate per-architecture result value
types for internal variables with no pre-defined type. Update for data
structure changes.
(show_convenience): Pass architecture to value_of_internalvar.
* eval.c (evaluate_subexp_standard): Likewise.
* infrun.c (siginfo_make_value): Add GDBARCH parameter. Use it
instead of current frame architecture. Return per-architecture type.
* value.h (set_internalvar_string): Add prototype.
* value.c (set_internalvar_string): New function.
* tracepoint.c (set_traceframe_context): Use it.
2009-07-02 Ulrich Weigand <uweigand@de.ibm.com>
* jv-lang.h (java_int_type, java_byte_type, java_short_type,

View File

@ -779,7 +779,8 @@ evaluate_subexp_standard (struct type *expect_type,
case OP_INTERNALVAR:
(*pos) += 2;
return value_of_internalvar (exp->elts[pc + 1].internalvar);
return value_of_internalvar (exp->gdbarch,
exp->elts[pc + 1].internalvar);
case OP_STRING:
tem = longest_to_int (exp->elts[pc + 1].longconst);

View File

@ -3181,6 +3181,11 @@ gdbtypes_post_init (struct gdbarch *gdbarch)
builtin_type->builtin_func_ptr =
lookup_pointer_type (lookup_function_type (builtin_type->builtin_void));
/* This type represents a GDB internal function. */
builtin_type->internal_fn =
init_type (TYPE_CODE_INTERNAL_FUNCTION, 0, 0,
"<internal function>", NULL);
return builtin_type;
}

View File

@ -999,6 +999,12 @@ struct builtin_type
However, all function pointer types are interconvertible, so void
(*) () can server as a generic function pointer. */
struct type *builtin_func_ptr;
/* Special-purpose types. */
/* This type is used to represent a GDB internal function. */
struct type *internal_fn;
};
/* Return the type table for the specified architecture. */

View File

@ -5263,29 +5263,21 @@ static struct lval_funcs siginfo_value_funcs =
};
/* Return a new value with the correct type for the siginfo object of
the current thread. Return a void value if there's no object
available. */
the current thread using architecture GDBARCH. Return a void value
if there's no object available. */
static struct value *
siginfo_make_value (struct internalvar *var)
siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var)
{
struct type *type;
struct gdbarch *gdbarch;
if (target_has_stack
&& !ptid_equal (inferior_ptid, null_ptid))
&& !ptid_equal (inferior_ptid, null_ptid)
&& gdbarch_get_siginfo_type_p (gdbarch))
{
gdbarch = get_frame_arch (get_current_frame ());
if (gdbarch_get_siginfo_type_p (gdbarch))
{
type = gdbarch_get_siginfo_type (gdbarch);
return allocate_computed_value (type, &siginfo_value_funcs, NULL);
}
struct type *type = gdbarch_get_siginfo_type (gdbarch);
return allocate_computed_value (type, &siginfo_value_funcs, NULL);
}
return allocate_value (builtin_type_void);
return allocate_value (builtin_type (gdbarch)->builtin_void);
}

View File

@ -228,12 +228,6 @@ set_traceframe_context (struct frame_info *trace_frame)
{
CORE_ADDR trace_pc;
static struct type *func_string, *file_string;
static struct type *func_range, *file_range;
struct value *func_val;
struct value *file_val;
int len;
if (trace_frame == NULL) /* Cease debugging any trace buffers. */
{
traceframe_fun = 0;
@ -261,20 +255,8 @@ set_traceframe_context (struct frame_info *trace_frame)
|| SYMBOL_LINKAGE_NAME (traceframe_fun) == NULL)
clear_internalvar (lookup_internalvar ("trace_func"));
else
{
len = strlen (SYMBOL_LINKAGE_NAME (traceframe_fun));
func_range = create_range_type (func_range,
builtin_type_int32, 0, len - 1);
func_string = create_array_type (func_string,
builtin_type_true_char, func_range);
func_val = allocate_value (func_string);
deprecated_set_value_type (func_val, func_string);
memcpy (value_contents_raw (func_val),
SYMBOL_LINKAGE_NAME (traceframe_fun),
len);
deprecated_set_value_modifiable (func_val, 0);
set_internalvar (lookup_internalvar ("trace_func"), func_val);
}
set_internalvar_string (lookup_internalvar ("trace_func"),
SYMBOL_LINKAGE_NAME (traceframe_fun));
/* Save file name as "$trace_file", a debugger variable visible to
users. */
@ -282,20 +264,8 @@ set_traceframe_context (struct frame_info *trace_frame)
|| traceframe_sal.symtab->filename == NULL)
clear_internalvar (lookup_internalvar ("trace_file"));
else
{
len = strlen (traceframe_sal.symtab->filename);
file_range = create_range_type (file_range,
builtin_type_int32, 0, len - 1);
file_string = create_array_type (file_string,
builtin_type_true_char, file_range);
file_val = allocate_value (file_string);
deprecated_set_value_type (file_val, file_string);
memcpy (value_contents_raw (file_val),
traceframe_sal.symtab->filename,
len);
deprecated_set_value_modifiable (file_val, 0);
set_internalvar (lookup_internalvar ("trace_file"), file_val);
}
set_internalvar_string (lookup_internalvar ("trace_file"),
traceframe_sal.symtab->filename);
}
/* ACTIONS functions: */

View File

@ -222,9 +222,6 @@ static struct value_history_chunk *value_history_chain;
static int value_history_count; /* Abs number of last entry stored */
/* The type of internal functions. */
static struct type *internal_fn_type;
/* List of all value objects currently allocated
(except for those released by calls to release_value)
@ -882,25 +879,67 @@ struct internalvar
{
struct internalvar *next;
char *name;
struct type *type;
/* True if this internalvar is the canonical name for a convenience
function. */
int canonical;
/* We support various different kinds of content of an internal variable.
enum internalvar_kind specifies the kind, and union internalvar_data
provides the data associated with this particular kind. */
/* If this function is non-NULL, it is used to compute a fresh value
on every access to the internalvar. */
internalvar_make_value make_value;
enum internalvar_kind
{
/* The internal variable is empty. */
INTERNALVAR_VOID,
/* The value of the internal variable is provided directly as
a GDB value object. */
INTERNALVAR_VALUE,
/* A fresh value is computed via a call-back routine on every
access to the internal variable. */
INTERNALVAR_MAKE_VALUE,
/* The internal variable holds a GDB internal convenience function. */
INTERNALVAR_FUNCTION,
/* The variable holds a simple scalar value. */
INTERNALVAR_SCALAR,
/* The variable holds a GDB-provided string. */
INTERNALVAR_STRING,
} kind;
/* To reduce dependencies on target properties (like byte order) that
may change during the lifetime of an internal variable, we store
simple scalar values as host objects. */
union internalvar_data
{
struct value *v;
struct internal_function *f;
LONGEST l;
CORE_ADDR a;
/* A value object used with INTERNALVAR_VALUE. */
struct value *value;
/* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
internalvar_make_value make_value;
/* The internal function used with INTERNALVAR_FUNCTION. */
struct
{
struct internal_function *function;
/* True if this is the canonical name for the function. */
int canonical;
} fn;
/* A scalar value used with INTERNALVAR_SCALAR. */
struct
{
/* If type is non-NULL, it will be used as the type to generate
a value for this internal variable. If type is NULL, a default
integer type for the architecture is used. */
struct type *type;
union
{
LONGEST l; /* Used with TYPE_CODE_INT and NULL types. */
CORE_ADDR a; /* Used with TYPE_CODE_PTR types. */
} val;
} scalar;
/* A string value used with INTERNALVAR_STRING. */
char *string;
} u;
};
@ -932,7 +971,7 @@ init_if_undefined_command (char* args, int from_tty)
/* Only evaluate the expression if the lvalue is void.
This may still fail if the expresssion is invalid. */
if (TYPE_CODE (intvar->type) == TYPE_CODE_VOID)
if (intvar->kind == INTERNALVAR_VOID)
evaluate_expression (expr);
do_cleanups (old_chain);
@ -967,9 +1006,7 @@ create_internalvar (const char *name)
struct internalvar *var;
var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
var->name = concat (name, (char *)NULL);
var->type = builtin_type_void;
var->make_value = NULL;
var->canonical = 0;
var->kind = INTERNALVAR_VOID;
var->next = internalvars;
internalvars = var;
return var;
@ -984,7 +1021,8 @@ struct internalvar *
create_internalvar_type_lazy (char *name, internalvar_make_value fun)
{
struct internalvar *var = create_internalvar (name);
var->make_value = fun;
var->kind = INTERNALVAR_MAKE_VALUE;
var->u.make_value = fun;
return var;
}
@ -1006,53 +1044,77 @@ lookup_internalvar (const char *name)
return create_internalvar (name);
}
/* Return current value of internal variable VAR. For variables that
are not inherently typed, use a value type appropriate for GDBARCH. */
struct value *
value_of_internalvar (struct internalvar *var)
value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
{
struct value *val;
if (var->make_value != NULL)
val = (*var->make_value) (var);
else
switch (var->kind)
{
switch (TYPE_CODE (var->type))
{
case TYPE_CODE_VOID:
case TYPE_CODE_INTERNAL_FUNCTION:
val = allocate_value (var->type);
break;
case INTERNALVAR_VOID:
val = allocate_value (builtin_type (gdbarch)->builtin_void);
break;
case TYPE_CODE_INT:
val = value_from_longest (var->type, var->u.l);
break;
case INTERNALVAR_FUNCTION:
val = allocate_value (builtin_type (gdbarch)->internal_fn);
break;
case TYPE_CODE_PTR:
val = value_from_pointer (var->type, var->u.a);
break;
case INTERNALVAR_SCALAR:
if (!var->u.scalar.type)
val = value_from_longest (builtin_type (gdbarch)->builtin_int,
var->u.scalar.val.l);
else if (TYPE_CODE (var->u.scalar.type) == TYPE_CODE_INT)
val = value_from_longest (var->u.scalar.type, var->u.scalar.val.l);
else if (TYPE_CODE (var->u.scalar.type) == TYPE_CODE_PTR)
val = value_from_pointer (var->u.scalar.type, var->u.scalar.val.a);
else
internal_error (__FILE__, __LINE__, "bad type");
break;
default:
val = value_copy (var->u.v);
break;
}
case INTERNALVAR_STRING:
val = value_cstring (var->u.string, strlen (var->u.string),
builtin_type (gdbarch)->builtin_char);
break;
case INTERNALVAR_VALUE:
val = value_copy (var->u.value);
if (value_lazy (val))
value_fetch_lazy (val);
break;
/* If the variable's value is a computed lvalue, we want
references to it to produce another computed lvalue, where
referencces and assignments actually operate through the
computed value's functions.
case INTERNALVAR_MAKE_VALUE:
val = (*var->u.make_value) (gdbarch, var);
break;
This means that internal variables with computed values
behave a little differently from other internal variables:
assignments to them don't just replace the previous value
altogether. At the moment, this seems like the behavior we
want. */
if (val->lval != lval_computed)
{
VALUE_LVAL (val) = lval_internalvar;
VALUE_INTERNALVAR (val) = var;
}
default:
internal_error (__FILE__, __LINE__, "bad kind");
}
/* Change the VALUE_LVAL to lval_internalvar so that future operations
on this value go back to affect the original internal variable.
Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
no underlying modifyable state in the internal variable.
Likewise, if the variable's value is a computed lvalue, we want
references to it to produce another computed lvalue, where
references and assignments actually operate through the
computed value's functions.
This means that internal variables with computed values
behave a little differently from other internal variables:
assignments to them don't just replace the previous value
altogether. At the moment, this seems like the behavior we
want. */
if (var->kind != INTERNALVAR_MAKE_VALUE
&& val->lval != lval_computed)
{
VALUE_LVAL (val) = lval_internalvar;
VALUE_INTERNALVAR (val) = var;
}
return val;
@ -1061,11 +1123,16 @@ value_of_internalvar (struct internalvar *var)
int
get_internalvar_integer (struct internalvar *var, LONGEST *result)
{
switch (TYPE_CODE (var->type))
switch (var->kind)
{
case TYPE_CODE_INT:
*result = var->u.l;
return 1;
case INTERNALVAR_SCALAR:
if (var->u.scalar.type == NULL
|| TYPE_CODE (var->u.scalar.type) == TYPE_CODE_INT)
{
*result = var->u.scalar.val.l;
return 1;
}
/* Fall through. */
default:
return 0;
@ -1076,10 +1143,10 @@ static int
get_internalvar_function (struct internalvar *var,
struct internal_function **result)
{
switch (TYPE_CODE (var->type))
switch (var->kind)
{
case TYPE_CODE_INTERNAL_FUNCTION:
*result = var->u.f;
case INTERNALVAR_FUNCTION:
*result = var->u.fn.function;
return 1;
default:
@ -1093,17 +1160,10 @@ set_internalvar_component (struct internalvar *var, int offset, int bitpos,
{
gdb_byte *addr;
switch (TYPE_CODE (var->type))
switch (var->kind)
{
case TYPE_CODE_VOID:
case TYPE_CODE_INTERNAL_FUNCTION:
case TYPE_CODE_INT:
case TYPE_CODE_PTR:
/* We can never get a component of a basic type. */
internal_error (__FILE__, __LINE__, "set_internalvar_component");
default:
addr = value_contents_writeable (var->u.v);
case INTERNALVAR_VALUE:
addr = value_contents_writeable (var->u.value);
if (bitsize)
modify_field (addr + offset,
@ -1112,52 +1172,65 @@ set_internalvar_component (struct internalvar *var, int offset, int bitpos,
memcpy (addr + offset, value_contents (newval),
TYPE_LENGTH (value_type (newval)));
break;
default:
/* We can never get a component of any other kind. */
internal_error (__FILE__, __LINE__, "set_internalvar_component");
}
}
void
set_internalvar (struct internalvar *var, struct value *val)
{
struct type *new_type = check_typedef (value_type (val));
enum internalvar_kind new_kind;
union internalvar_data new_data = { 0 };
if (var->canonical)
if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
error (_("Cannot overwrite convenience function %s"), var->name);
/* Prepare new contents. */
switch (TYPE_CODE (new_type))
switch (TYPE_CODE (check_typedef (value_type (val))))
{
case TYPE_CODE_VOID:
new_kind = INTERNALVAR_VOID;
break;
case TYPE_CODE_INTERNAL_FUNCTION:
gdb_assert (VALUE_LVAL (val) == lval_internalvar);
get_internalvar_function (VALUE_INTERNALVAR (val), &new_data.f);
new_kind = INTERNALVAR_FUNCTION;
get_internalvar_function (VALUE_INTERNALVAR (val),
&new_data.fn.function);
/* Copies created here are never canonical. */
break;
case TYPE_CODE_INT:
new_data.l = value_as_long (val);
new_kind = INTERNALVAR_SCALAR;
new_data.scalar.type = value_type (val);
new_data.scalar.val.l = value_as_long (val);
break;
case TYPE_CODE_PTR:
new_data.a = value_as_address (val);
new_kind = INTERNALVAR_SCALAR;
new_data.scalar.type = value_type (val);
new_data.scalar.val.a = value_as_address (val);
break;
default:
new_data.v = value_copy (val);
new_data.v->modifiable = 1;
new_kind = INTERNALVAR_VALUE;
new_data.value = value_copy (val);
new_data.value->modifiable = 1;
/* Force the value to be fetched from the target now, to avoid problems
later when this internalvar is referenced and the target is gone or
has changed. */
if (value_lazy (new_data.v))
value_fetch_lazy (new_data.v);
if (value_lazy (new_data.value))
value_fetch_lazy (new_data.value);
/* Release the value from the value chain to prevent it from being
deleted by free_all_values. From here on this function should not
call error () until new_data is installed into the var->u to avoid
leaking memory. */
release_value (new_data.v);
release_value (new_data.value);
break;
}
@ -1165,7 +1238,7 @@ set_internalvar (struct internalvar *var, struct value *val)
clear_internalvar (var);
/* Switch over. */
var->type = new_type;
var->kind = new_kind;
var->u = new_data;
/* End code which must not call error(). */
}
@ -1176,9 +1249,19 @@ set_internalvar_integer (struct internalvar *var, LONGEST l)
/* Clean up old contents. */
clear_internalvar (var);
/* Use a platform-independent 32-bit integer type. */
var->type = builtin_type_int32;
var->u.l = l;
var->kind = INTERNALVAR_SCALAR;
var->u.scalar.type = NULL;
var->u.scalar.val.l = l;
}
void
set_internalvar_string (struct internalvar *var, const char *string)
{
/* Clean up old contents. */
clear_internalvar (var);
var->kind = INTERNALVAR_STRING;
var->u.string = xstrdup (string);
}
static void
@ -1187,29 +1270,32 @@ set_internalvar_function (struct internalvar *var, struct internal_function *f)
/* Clean up old contents. */
clear_internalvar (var);
var->type = internal_fn_type;
var->u.f = f;
var->kind = INTERNALVAR_FUNCTION;
var->u.fn.function = f;
var->u.fn.canonical = 1;
/* Variables installed here are always the canonical version. */
}
void
clear_internalvar (struct internalvar *var)
{
/* Clean up old contents. */
switch (TYPE_CODE (var->type))
switch (var->kind)
{
case TYPE_CODE_VOID:
case TYPE_CODE_INTERNAL_FUNCTION:
case TYPE_CODE_INT:
case TYPE_CODE_PTR:
case INTERNALVAR_VALUE:
value_free (var->u.value);
break;
case INTERNALVAR_STRING:
xfree (var->u.string);
break;
default:
value_free (var->u.v);
break;
}
/* Set to void type. */
var->type = builtin_type_void;
/* Reset to void kind. */
var->kind = INTERNALVAR_VOID;
}
char *
@ -1288,7 +1374,6 @@ add_internal_function (const char *name, const char *doc,
ifn = create_internal_function (name, handler, cookie);
set_internalvar_function (var, ifn);
var->canonical = 1;
cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
&functionlist);
@ -1311,6 +1396,26 @@ preserve_one_value (struct value *value, struct objfile *objfile,
copied_types);
}
/* Likewise for internal variable VAR. */
static void
preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
htab_t copied_types)
{
switch (var->kind)
{
case INTERNALVAR_SCALAR:
if (var->u.scalar.type && TYPE_OBJFILE (var->u.scalar.type) == objfile)
var->u.scalar.type
= copy_type_recursive (objfile, var->u.scalar.type, copied_types);
break;
case INTERNALVAR_VALUE:
preserve_one_value (var->u.value, objfile, copied_types);
break;
}
}
/* Update the internal variables and value history when OBJFILE is
discarded; we must copy the types out of the objfile. New global types
will be created for every convenience variable which currently points to
@ -1336,23 +1441,7 @@ preserve_values (struct objfile *objfile)
preserve_one_value (cur->values[i], objfile, copied_types);
for (var = internalvars; var; var = var->next)
{
if (TYPE_OBJFILE (var->type) == objfile)
var->type = copy_type_recursive (objfile, var->type, copied_types);
switch (TYPE_CODE (var->type))
{
case TYPE_CODE_VOID:
case TYPE_CODE_INTERNAL_FUNCTION:
case TYPE_CODE_INT:
case TYPE_CODE_PTR:
break;
default:
preserve_one_value (var->u.v, objfile, copied_types);
break;
}
}
preserve_one_internalvar (var, objfile, copied_types);
for (val = values_in_python; val; val = val->next)
preserve_one_value (val, objfile, copied_types);
@ -1363,6 +1452,7 @@ preserve_values (struct objfile *objfile)
static void
show_convenience (char *ignore, int from_tty)
{
struct gdbarch *gdbarch = current_gdbarch;
struct internalvar *var;
int varseen = 0;
struct value_print_options opts;
@ -1375,7 +1465,7 @@ show_convenience (char *ignore, int from_tty)
varseen = 1;
}
printf_filtered (("$%s = "), var->name);
value_print (value_of_internalvar (var), gdb_stdout,
value_print (value_of_internalvar (gdbarch, var), gdb_stdout,
&opts);
printf_filtered (("\n"));
}
@ -2172,8 +2262,4 @@ VARIABLE is already initialized."));
add_prefix_cmd ("function", no_class, function_command, _("\
Placeholder command for showing help on convenience functions."),
&functionlist, "function ", 0, &cmdlist);
internal_fn_type = alloc_type (NULL);
TYPE_CODE (internal_fn_type) = TYPE_CODE_INTERNAL_FUNCTION;
TYPE_NAME (internal_fn_type) = "<internal function>";
}

View File

@ -522,7 +522,8 @@ extern void binop_promote (const struct language_defn *language,
extern struct value *access_value_history (int num);
extern struct value *value_of_internalvar (struct internalvar *var);
extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
struct internalvar *var);
extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
@ -530,6 +531,9 @@ extern void set_internalvar (struct internalvar *var, struct value *val);
extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
extern void set_internalvar_string (struct internalvar *var,
const char *string);
extern void clear_internalvar (struct internalvar *var);
extern void set_internalvar_component (struct internalvar *var,
@ -541,8 +545,8 @@ extern struct internalvar *lookup_only_internalvar (const char *name);
extern struct internalvar *create_internalvar (const char *name);
typedef struct value * (*internalvar_make_value) (struct internalvar *);
typedef struct value * (*internalvar_make_value) (struct gdbarch *,
struct internalvar *);
extern struct internalvar *
create_internalvar_type_lazy (char *name, internalvar_make_value fun);