old-cross-binutils/gdb/python/py-prettyprint.c
Pedro Alves 492d29ea1c Split TRY_CATCH into TRY + CATCH
This patch splits the TRY_CATCH macro into three, so that we go from
this:

~~~
  volatile gdb_exception ex;

  TRY_CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  if (ex.reason < 0)
    {
    }
~~~

to this:

~~~
  TRY
    {
    }
  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH
~~~

Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.

This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.

TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:

  TRY
    {
    }

  // some code here.

  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH

Just like it isn't valid to do that with C++'s native try/catch.

By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.

The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved.  After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch].  The result was folded into this patch so that GDB
still builds at each incremental step.

END_CATCH is necessary for two reasons:

First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:

  #define CATCH(EXCEPTION, mask) \
    for (struct gdb_exception EXCEPTION; \
         exceptions_state_mc_catch (&EXCEPTION, MASK); \
	 EXCEPTION = exception_none)

would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.

Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow.  That will
be done in END_CATCH.

After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.

IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.

gdb/ChangeLog.
2015-03-07  Pedro Alves  <palves@redhat.com>

	* common/common-exceptions.c (struct catcher) <exception>: No
	longer a pointer to volatile exception.  Now an exception value.
	<mask>: Delete field.
	(exceptions_state_mc_init): Remove all parameters.  Adjust.
	(exceptions_state_mc): No longer pop the catcher here.
	(exceptions_state_mc_catch): New function.
	(throw_exception): Adjust.
	* common/common-exceptions.h (exceptions_state_mc_init): Remove
	all parameters.
	(exceptions_state_mc_catch): Declare.
	(TRY_CATCH): Rename to ...
	(TRY): ... this.  Remove EXCEPTION and MASK parameters.
	(CATCH, END_CATCH): New.
	All callers adjusted.

gdb/gdbserver/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
	instead.
2015-03-07 15:14:14 +00:00

852 lines
22 KiB
C

/* Python pretty-printing
Copyright (C) 2008-2015 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "objfiles.h"
#include "symtab.h"
#include "language.h"
#include "valprint.h"
#include "extension-priv.h"
#include "python.h"
#include "python-internal.h"
/* Return type of print_string_repr. */
enum string_repr_result
{
/* The string method returned None. */
string_repr_none,
/* The string method had an error. */
string_repr_error,
/* Everything ok. */
string_repr_ok
};
/* Helper function for find_pretty_printer which iterates over a list,
calls each function and inspects output. This will return a
printer object if one recognizes VALUE. If no printer is found, it
will return None. On error, it will set the Python error and
return NULL. */
static PyObject *
search_pp_list (PyObject *list, PyObject *value)
{
Py_ssize_t pp_list_size, list_index;
PyObject *function, *printer = NULL;
pp_list_size = PyList_Size (list);
for (list_index = 0; list_index < pp_list_size; list_index++)
{
function = PyList_GetItem (list, list_index);
if (! function)
return NULL;
/* Skip if disabled. */
if (PyObject_HasAttr (function, gdbpy_enabled_cst))
{
PyObject *attr = PyObject_GetAttr (function, gdbpy_enabled_cst);
int cmp;
if (!attr)
return NULL;
cmp = PyObject_IsTrue (attr);
Py_DECREF (attr);
if (cmp == -1)
return NULL;
if (!cmp)
continue;
}
printer = PyObject_CallFunctionObjArgs (function, value, NULL);
if (! printer)
return NULL;
else if (printer != Py_None)
return printer;
Py_DECREF (printer);
}
Py_RETURN_NONE;
}
/* Subroutine of find_pretty_printer to simplify it.
Look for a pretty-printer to print VALUE in all objfiles.
The result is NULL if there's an error and the search should be terminated.
The result is Py_None, suitably inc-ref'd, if no pretty-printer was found.
Otherwise the result is the pretty-printer function, suitably inc-ref'd. */
static PyObject *
find_pretty_printer_from_objfiles (PyObject *value)
{
PyObject *pp_list;
PyObject *function;
struct objfile *obj;
ALL_OBJFILES (obj)
{
PyObject *objf = objfile_to_objfile_object (obj);
if (!objf)
{
/* Ignore the error and continue. */
PyErr_Clear ();
continue;
}
pp_list = objfpy_get_printers (objf, NULL);
function = search_pp_list (pp_list, value);
Py_XDECREF (pp_list);
/* If there is an error in any objfile list, abort the search and exit. */
if (! function)
return NULL;
if (function != Py_None)
return function;
Py_DECREF (function);
}
Py_RETURN_NONE;
}
/* Subroutine of find_pretty_printer to simplify it.
Look for a pretty-printer to print VALUE in the current program space.
The result is NULL if there's an error and the search should be terminated.
The result is Py_None, suitably inc-ref'd, if no pretty-printer was found.
Otherwise the result is the pretty-printer function, suitably inc-ref'd. */
static PyObject *
find_pretty_printer_from_progspace (PyObject *value)
{
PyObject *pp_list;
PyObject *function;
PyObject *obj = pspace_to_pspace_object (current_program_space);
if (!obj)
return NULL;
pp_list = pspy_get_printers (obj, NULL);
function = search_pp_list (pp_list, value);
Py_XDECREF (pp_list);
return function;
}
/* Subroutine of find_pretty_printer to simplify it.
Look for a pretty-printer to print VALUE in the gdb module.
The result is NULL if there's an error and the search should be terminated.
The result is Py_None, suitably inc-ref'd, if no pretty-printer was found.
Otherwise the result is the pretty-printer function, suitably inc-ref'd. */
static PyObject *
find_pretty_printer_from_gdb (PyObject *value)
{
PyObject *pp_list;
PyObject *function;
/* Fetch the global pretty printer list. */
if (gdb_python_module == NULL
|| ! PyObject_HasAttrString (gdb_python_module, "pretty_printers"))
Py_RETURN_NONE;
pp_list = PyObject_GetAttrString (gdb_python_module, "pretty_printers");
if (pp_list == NULL || ! PyList_Check (pp_list))
{
Py_XDECREF (pp_list);
Py_RETURN_NONE;
}
function = search_pp_list (pp_list, value);
Py_XDECREF (pp_list);
return function;
}
/* Find the pretty-printing constructor function for VALUE. If no
pretty-printer exists, return None. If one exists, return a new
reference. On error, set the Python error and return NULL. */
static PyObject *
find_pretty_printer (PyObject *value)
{
PyObject *function;
/* Look at the pretty-printer list for each objfile
in the current program-space. */
function = find_pretty_printer_from_objfiles (value);
if (function == NULL || function != Py_None)
return function;
Py_DECREF (function);
/* Look at the pretty-printer list for the current program-space. */
function = find_pretty_printer_from_progspace (value);
if (function == NULL || function != Py_None)
return function;
Py_DECREF (function);
/* Look at the pretty-printer list in the gdb module. */
function = find_pretty_printer_from_gdb (value);
return function;
}
/* Pretty-print a single value, via the printer object PRINTER.
If the function returns a string, a PyObject containing the string
is returned. If the function returns Py_NONE that means the pretty
printer returned the Python None as a value. Otherwise, if the
function returns a value, *OUT_VALUE is set to the value, and NULL
is returned. On error, *OUT_VALUE is set to NULL, NULL is
returned, with a python exception set. */
static PyObject *
pretty_print_one_value (PyObject *printer, struct value **out_value)
{
PyObject *result = NULL;
*out_value = NULL;
TRY
{
result = PyObject_CallMethodObjArgs (printer, gdbpy_to_string_cst, NULL);
if (result)
{
if (! gdbpy_is_string (result) && ! gdbpy_is_lazy_string (result)
&& result != Py_None)
{
*out_value = convert_value_from_python (result);
if (PyErr_Occurred ())
*out_value = NULL;
Py_DECREF (result);
result = NULL;
}
}
}
CATCH (except, RETURN_MASK_ALL)
{
}
END_CATCH
return result;
}
/* Return the display hint for the object printer, PRINTER. Return
NULL if there is no display_hint method, or if the method did not
return a string. On error, print stack trace and return NULL. On
success, return an xmalloc()d string. */
char *
gdbpy_get_display_hint (PyObject *printer)
{
PyObject *hint;
char *result = NULL;
if (! PyObject_HasAttr (printer, gdbpy_display_hint_cst))
return NULL;
hint = PyObject_CallMethodObjArgs (printer, gdbpy_display_hint_cst, NULL);
if (hint)
{
if (gdbpy_is_string (hint))
{
result = python_string_to_host_string (hint);
if (result == NULL)
gdbpy_print_stack ();
}
Py_DECREF (hint);
}
else
gdbpy_print_stack ();
return result;
}
/* A wrapper for gdbpy_print_stack that ignores MemoryError. */
static void
print_stack_unless_memory_error (struct ui_file *stream)
{
if (PyErr_ExceptionMatches (gdbpy_gdb_memory_error))
{
struct cleanup *cleanup;
PyObject *type, *value, *trace;
char *msg;
PyErr_Fetch (&type, &value, &trace);
cleanup = make_cleanup_py_decref (type);
make_cleanup_py_decref (value);
make_cleanup_py_decref (trace);
msg = gdbpy_exception_to_string (type, value);
make_cleanup (xfree, msg);
if (msg == NULL || *msg == '\0')
fprintf_filtered (stream, _("<error reading variable>"));
else
fprintf_filtered (stream, _("<error reading variable: %s>"), msg);
do_cleanups (cleanup);
}
else
gdbpy_print_stack ();
}
/* Helper for gdbpy_apply_val_pretty_printer which calls to_string and
formats the result. */
static enum string_repr_result
print_string_repr (PyObject *printer, const char *hint,
struct ui_file *stream, int recurse,
const struct value_print_options *options,
const struct language_defn *language,
struct gdbarch *gdbarch)
{
struct value *replacement = NULL;
PyObject *py_str = NULL;
enum string_repr_result result = string_repr_ok;
py_str = pretty_print_one_value (printer, &replacement);
if (py_str)
{
struct cleanup *cleanup = make_cleanup_py_decref (py_str);
if (py_str == Py_None)
result = string_repr_none;
else if (gdbpy_is_lazy_string (py_str))
{
CORE_ADDR addr;
long length;
struct type *type;
char *encoding = NULL;
struct value_print_options local_opts = *options;
make_cleanup (free_current_contents, &encoding);
gdbpy_extract_lazy_string (py_str, &addr, &type,
&length, &encoding);
local_opts.addressprint = 0;
val_print_string (type, encoding, addr, (int) length,
stream, &local_opts);
}
else
{
PyObject *string;
string = python_string_to_target_python_string (py_str);
if (string)
{
char *output;
long length;
struct type *type;
make_cleanup_py_decref (string);
#ifdef IS_PY3K
output = PyBytes_AS_STRING (string);
length = PyBytes_GET_SIZE (string);
#else
output = PyString_AsString (string);
length = PyString_Size (string);
#endif
type = builtin_type (gdbarch)->builtin_char;
if (hint && !strcmp (hint, "string"))
LA_PRINT_STRING (stream, type, (gdb_byte *) output,
length, NULL, 0, options);
else
fputs_filtered (output, stream);
}
else
{
result = string_repr_error;
print_stack_unless_memory_error (stream);
}
}
do_cleanups (cleanup);
}
else if (replacement)
{
struct value_print_options opts = *options;
opts.addressprint = 0;
common_val_print (replacement, stream, recurse, &opts, language);
}
else
{
result = string_repr_error;
print_stack_unless_memory_error (stream);
}
return result;
}
#ifndef IS_PY3K
static void
py_restore_tstate (void *p)
{
PyFrameObject *frame = p;
PyThreadState *tstate = PyThreadState_GET ();
tstate->frame = frame;
}
/* Create a dummy PyFrameObject, needed to work around
a Python-2.4 bug with generators. */
static PyObject *
push_dummy_python_frame (void)
{
PyObject *empty_string, *null_tuple, *globals;
PyCodeObject *code;
PyFrameObject *frame;
PyThreadState *tstate;
empty_string = PyString_FromString ("");
if (!empty_string)
return NULL;
null_tuple = PyTuple_New (0);
if (!null_tuple)
{
Py_DECREF (empty_string);
return NULL;
}
code = PyCode_New (0, /* argcount */
0, /* nlocals */
0, /* stacksize */
0, /* flags */
empty_string, /* code */
null_tuple, /* consts */
null_tuple, /* names */
null_tuple, /* varnames */
#if PYTHON_API_VERSION >= 1010
null_tuple, /* freevars */
null_tuple, /* cellvars */
#endif
empty_string, /* filename */
empty_string, /* name */
1, /* firstlineno */
empty_string /* lnotab */
);
Py_DECREF (empty_string);
Py_DECREF (null_tuple);
if (!code)
return NULL;
globals = PyDict_New ();
if (!globals)
{
Py_DECREF (code);
return NULL;
}
tstate = PyThreadState_GET ();
frame = PyFrame_New (tstate, code, globals, NULL);
Py_DECREF (globals);
Py_DECREF (code);
if (!frame)
return NULL;
tstate->frame = frame;
make_cleanup (py_restore_tstate, frame->f_back);
return (PyObject *) frame;
}
#endif
/* Helper for gdbpy_apply_val_pretty_printer that formats children of the
printer, if any exist. If is_py_none is true, then nothing has
been printed by to_string, and format output accordingly. */
static void
print_children (PyObject *printer, const char *hint,
struct ui_file *stream, int recurse,
const struct value_print_options *options,
const struct language_defn *language,
int is_py_none)
{
int is_map, is_array, done_flag, pretty;
unsigned int i;
PyObject *children, *iter;
#ifndef IS_PY3K
PyObject *frame;
#endif
struct cleanup *cleanups;
if (! PyObject_HasAttr (printer, gdbpy_children_cst))
return;
/* If we are printing a map or an array, we want some special
formatting. */
is_map = hint && ! strcmp (hint, "map");
is_array = hint && ! strcmp (hint, "array");
children = PyObject_CallMethodObjArgs (printer, gdbpy_children_cst,
NULL);
if (! children)
{
print_stack_unless_memory_error (stream);
return;
}
cleanups = make_cleanup_py_decref (children);
iter = PyObject_GetIter (children);
if (!iter)
{
print_stack_unless_memory_error (stream);
goto done;
}
make_cleanup_py_decref (iter);
/* Use the prettyformat_arrays option if we are printing an array,
and the pretty option otherwise. */
if (is_array)
pretty = options->prettyformat_arrays;
else
{
if (options->prettyformat == Val_prettyformat)
pretty = 1;
else
pretty = options->prettyformat_structs;
}
/* Manufacture a dummy Python frame to work around Python 2.4 bug,
where it insists on having a non-NULL tstate->frame when
a generator is called. */
#ifndef IS_PY3K
frame = push_dummy_python_frame ();
if (!frame)
{
gdbpy_print_stack ();
goto done;
}
make_cleanup_py_decref (frame);
#endif
done_flag = 0;
for (i = 0; i < options->print_max; ++i)
{
PyObject *py_v, *item = PyIter_Next (iter);
const char *name;
struct cleanup *inner_cleanup;
if (! item)
{
if (PyErr_Occurred ())
print_stack_unless_memory_error (stream);
/* Set a flag so we can know whether we printed all the
available elements. */
else
done_flag = 1;
break;
}
if (! PyArg_ParseTuple (item, "sO", &name, &py_v))
{
gdbpy_print_stack ();
Py_DECREF (item);
continue;
}
inner_cleanup = make_cleanup_py_decref (item);
/* Print initial "{". For other elements, there are three
cases:
1. Maps. Print a "," after each value element.
2. Arrays. Always print a ",".
3. Other. Always print a ",". */
if (i == 0)
{
if (is_py_none)
fputs_filtered ("{", stream);
else
fputs_filtered (" = {", stream);
}
else if (! is_map || i % 2 == 0)
fputs_filtered (pretty ? "," : ", ", stream);
/* In summary mode, we just want to print "= {...}" if there is
a value. */
if (options->summary)
{
/* This increment tricks the post-loop logic to print what
we want. */
++i;
/* Likewise. */
pretty = 0;
break;
}
if (! is_map || i % 2 == 0)
{
if (pretty)
{
fputs_filtered ("\n", stream);
print_spaces_filtered (2 + 2 * recurse, stream);
}
else
wrap_here (n_spaces (2 + 2 *recurse));
}
if (is_map && i % 2 == 0)
fputs_filtered ("[", stream);
else if (is_array)
{
/* We print the index, not whatever the child method
returned as the name. */
if (options->print_array_indexes)
fprintf_filtered (stream, "[%d] = ", i);
}
else if (! is_map)
{
fputs_filtered (name, stream);
fputs_filtered (" = ", stream);
}
if (gdbpy_is_lazy_string (py_v))
{
CORE_ADDR addr;
struct type *type;
long length;
char *encoding = NULL;
struct value_print_options local_opts = *options;
make_cleanup (free_current_contents, &encoding);
gdbpy_extract_lazy_string (py_v, &addr, &type, &length, &encoding);
local_opts.addressprint = 0;
val_print_string (type, encoding, addr, (int) length, stream,
&local_opts);
}
else if (gdbpy_is_string (py_v))
{
char *output;
output = python_string_to_host_string (py_v);
if (!output)
gdbpy_print_stack ();
else
{
fputs_filtered (output, stream);
xfree (output);
}
}
else
{
struct value *value = convert_value_from_python (py_v);
if (value == NULL)
{
gdbpy_print_stack ();
error (_("Error while executing Python code."));
}
else
common_val_print (value, stream, recurse + 1, options, language);
}
if (is_map && i % 2 == 0)
fputs_filtered ("] = ", stream);
do_cleanups (inner_cleanup);
}
if (i)
{
if (!done_flag)
{
if (pretty)
{
fputs_filtered ("\n", stream);
print_spaces_filtered (2 + 2 * recurse, stream);
}
fputs_filtered ("...", stream);
}
if (pretty)
{
fputs_filtered ("\n", stream);
print_spaces_filtered (2 * recurse, stream);
}
fputs_filtered ("}", stream);
}
done:
do_cleanups (cleanups);
}
enum ext_lang_rc
gdbpy_apply_val_pretty_printer (const struct extension_language_defn *extlang,
struct type *type, const gdb_byte *valaddr,
int embedded_offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
const struct value *val,
const struct value_print_options *options,
const struct language_defn *language)
{
struct gdbarch *gdbarch = get_type_arch (type);
PyObject *printer = NULL;
PyObject *val_obj = NULL;
struct value *value;
char *hint = NULL;
struct cleanup *cleanups;
enum ext_lang_rc result = EXT_LANG_RC_NOP;
enum string_repr_result print_result;
/* No pretty-printer support for unavailable values. */
if (!value_bytes_available (val, embedded_offset, TYPE_LENGTH (type)))
return EXT_LANG_RC_NOP;
if (!gdb_python_initialized)
return EXT_LANG_RC_NOP;
cleanups = ensure_python_env (gdbarch, language);
/* Instantiate the printer. */
if (valaddr)
valaddr += embedded_offset;
value = value_from_contents_and_address (type, valaddr,
address + embedded_offset);
set_value_component_location (value, val);
/* set_value_component_location resets the address, so we may
need to set it again. */
if (VALUE_LVAL (value) != lval_internalvar
&& VALUE_LVAL (value) != lval_internalvar_component
&& VALUE_LVAL (value) != lval_computed)
set_value_address (value, address + embedded_offset);
val_obj = value_to_value_object (value);
if (! val_obj)
{
result = EXT_LANG_RC_ERROR;
goto done;
}
/* Find the constructor. */
printer = find_pretty_printer (val_obj);
Py_DECREF (val_obj);
if (printer == NULL)
{
result = EXT_LANG_RC_ERROR;
goto done;
}
make_cleanup_py_decref (printer);
if (printer == Py_None)
{
result = EXT_LANG_RC_NOP;
goto done;
}
/* If we are printing a map, we want some special formatting. */
hint = gdbpy_get_display_hint (printer);
make_cleanup (free_current_contents, &hint);
/* Print the section */
print_result = print_string_repr (printer, hint, stream, recurse,
options, language, gdbarch);
if (print_result != string_repr_error)
print_children (printer, hint, stream, recurse, options, language,
print_result == string_repr_none);
result = EXT_LANG_RC_OK;
done:
if (PyErr_Occurred ())
print_stack_unless_memory_error (stream);
do_cleanups (cleanups);
return result;
}
/* Apply a pretty-printer for the varobj code. PRINTER_OBJ is the
print object. It must have a 'to_string' method (but this is
checked by varobj, not here) which takes no arguments and
returns a string. The printer will return a value and in the case
of a Python string being returned, this function will return a
PyObject containing the string. For any other type, *REPLACEMENT is
set to the replacement value and this function returns NULL. On
error, *REPLACEMENT is set to NULL and this function also returns
NULL. */
PyObject *
apply_varobj_pretty_printer (PyObject *printer_obj,
struct value **replacement,
struct ui_file *stream)
{
PyObject *py_str = NULL;
*replacement = NULL;
py_str = pretty_print_one_value (printer_obj, replacement);
if (*replacement == NULL && py_str == NULL)
print_stack_unless_memory_error (stream);
return py_str;
}
/* Find a pretty-printer object for the varobj module. Returns a new
reference to the object if successful; returns NULL if not. VALUE
is the value for which a printer tests to determine if it
can pretty-print the value. */
PyObject *
gdbpy_get_varobj_pretty_printer (struct value *value)
{
PyObject *val_obj;
PyObject *pretty_printer = NULL;
TRY
{
value = value_copy (value);
}
CATCH (except, RETURN_MASK_ALL)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
END_CATCH
val_obj = value_to_value_object (value);
if (! val_obj)
return NULL;
pretty_printer = find_pretty_printer (val_obj);
Py_DECREF (val_obj);
return pretty_printer;
}
/* A Python function which wraps find_pretty_printer and instantiates
the resulting class. This accepts a Value argument and returns a
pretty printer instance, or None. This function is useful as an
argument to the MI command -var-set-visualizer. */
PyObject *
gdbpy_default_visualizer (PyObject *self, PyObject *args)
{
PyObject *val_obj;
PyObject *cons;
struct value *value;
if (! PyArg_ParseTuple (args, "O", &val_obj))
return NULL;
value = value_object_to_value (val_obj);
if (! value)
{
PyErr_SetString (PyExc_TypeError,
_("Argument must be a gdb.Value."));
return NULL;
}
cons = find_pretty_printer (val_obj);
return cons;
}