1 /* Python pretty-printing
3 Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "exceptions.h"
30 #include "python-internal.h"
32 /* Helper function for find_pretty_printer which iterates over a list,
33 calls each function and inspects output. This will return a
34 printer object if one recognizes VALUE. If no printer is found, it
35 will return None. On error, it will set the Python error and
39 search_pp_list (PyObject
*list
, PyObject
*value
)
41 Py_ssize_t pp_list_size
, list_index
;
42 PyObject
*function
, *printer
= NULL
;
44 pp_list_size
= PyList_Size (list
);
45 for (list_index
= 0; list_index
< pp_list_size
; list_index
++)
47 function
= PyList_GetItem (list
, list_index
);
51 /* Skip if disabled. */
52 if (PyObject_HasAttr (function
, gdbpy_enabled_cst
)
53 && ! PyObject_IsTrue (PyObject_GetAttr (function
, gdbpy_enabled_cst
)))
56 printer
= PyObject_CallFunctionObjArgs (function
, value
, NULL
);
59 else if (printer
!= Py_None
)
68 /* Subroutine of find_pretty_printer to simplify it.
69 Look for a pretty-printer to print VALUE in all objfiles.
70 The result is NULL if there's an error and the search should be terminated.
71 The result is Py_None, suitably inc-ref'd, if no pretty-printer was found.
72 Otherwise the result is the pretty-printer function, suitably inc-ref'd. */
75 find_pretty_printer_from_objfiles (PyObject
*value
)
83 PyObject
*objf
= objfile_to_objfile_object (obj
);
86 /* Ignore the error and continue. */
91 pp_list
= objfpy_get_printers (objf
, NULL
);
92 function
= search_pp_list (pp_list
, value
);
95 /* If there is an error in any objfile list, abort the search and exit. */
99 if (function
!= Py_None
)
102 Py_DECREF (function
);
108 /* Subroutine of find_pretty_printer to simplify it.
109 Look for a pretty-printer to print VALUE in the current program space.
110 The result is NULL if there's an error and the search should be terminated.
111 The result is Py_None, suitably inc-ref'd, if no pretty-printer was found.
112 Otherwise the result is the pretty-printer function, suitably inc-ref'd. */
115 find_pretty_printer_from_progspace (PyObject
*value
)
119 PyObject
*obj
= pspace_to_pspace_object (current_program_space
);
123 pp_list
= pspy_get_printers (obj
, NULL
);
124 function
= search_pp_list (pp_list
, value
);
125 Py_XDECREF (pp_list
);
129 /* Subroutine of find_pretty_printer to simplify it.
130 Look for a pretty-printer to print VALUE in the gdb module.
131 The result is NULL if there's an error and the search should be terminated.
132 The result is Py_None, suitably inc-ref'd, if no pretty-printer was found.
133 Otherwise the result is the pretty-printer function, suitably inc-ref'd. */
136 find_pretty_printer_from_gdb (PyObject
*value
)
141 /* Fetch the global pretty printer dictionary. */
142 if (! PyObject_HasAttrString (gdb_module
, "pretty_printers"))
144 pp_list
= PyObject_GetAttrString (gdb_module
, "pretty_printers");
145 if (pp_list
== NULL
|| ! PyList_Check (pp_list
))
147 Py_XDECREF (pp_list
);
151 function
= search_pp_list (pp_list
, value
);
152 Py_XDECREF (pp_list
);
156 /* Find the pretty-printing constructor function for VALUE. If no
157 pretty-printer exists, return None. If one exists, return a new
158 reference. On error, set the Python error and return NULL. */
161 find_pretty_printer (PyObject
*value
)
165 /* Look at the pretty-printer dictionary for each objfile
166 in the current program-space. */
167 function
= find_pretty_printer_from_objfiles (value
);
168 if (function
== NULL
|| function
!= Py_None
)
170 Py_DECREF (function
);
172 /* Look at the pretty-printer dictionary for the current program-space. */
173 function
= find_pretty_printer_from_progspace (value
);
174 if (function
== NULL
|| function
!= Py_None
)
176 Py_DECREF (function
);
178 /* Look at the pretty-printer dictionary in the gdb module. */
179 function
= find_pretty_printer_from_gdb (value
);
183 /* Pretty-print a single value, via the printer object PRINTER.
184 If the function returns a string, a PyObject containing the string
185 is returned. If the function returns Py_NONE that means the pretty
186 printer returned the Python None as a value. Otherwise, if the
187 function returns a value, *OUT_VALUE is set to the value, and NULL
188 is returned. On error, *OUT_VALUE is set to NULL, and NULL is
192 pretty_print_one_value (PyObject
*printer
, struct value
**out_value
)
194 volatile struct gdb_exception except
;
195 PyObject
*result
= NULL
;
198 TRY_CATCH (except
, RETURN_MASK_ALL
)
200 result
= PyObject_CallMethodObjArgs (printer
, gdbpy_to_string_cst
, NULL
);
203 if (! gdbpy_is_string (result
) && ! gdbpy_is_lazy_string (result
)
204 && result
!= Py_None
)
206 *out_value
= convert_value_from_python (result
);
207 if (PyErr_Occurred ())
218 /* Return the display hint for the object printer, PRINTER. Return
219 NULL if there is no display_hint method, or if the method did not
220 return a string. On error, print stack trace and return NULL. On
221 success, return an xmalloc()d string. */
223 gdbpy_get_display_hint (PyObject
*printer
)
228 if (! PyObject_HasAttr (printer
, gdbpy_display_hint_cst
))
231 hint
= PyObject_CallMethodObjArgs (printer
, gdbpy_display_hint_cst
, NULL
);
234 if (gdbpy_is_string (hint
))
235 result
= python_string_to_host_string (hint
);
239 gdbpy_print_stack ();
244 /* Helper for apply_val_pretty_printer which calls to_string and
245 formats the result. If the value returnd is Py_None, nothing is
246 printed and the function returns a 1; in all other cases data is
247 printed as given by the pretty printer and the function returns 0.
250 print_string_repr (PyObject
*printer
, const char *hint
,
251 struct ui_file
*stream
, int recurse
,
252 const struct value_print_options
*options
,
253 const struct language_defn
*language
,
254 struct gdbarch
*gdbarch
)
256 struct value
*replacement
= NULL
;
257 PyObject
*py_str
= NULL
;
260 py_str
= pretty_print_one_value (printer
, &replacement
);
263 if (py_str
== Py_None
)
267 gdb_byte
*output
= NULL
;
270 char *encoding
= NULL
;
271 PyObject
*string
= NULL
;
274 is_lazy
= gdbpy_is_lazy_string (py_str
);
276 output
= gdbpy_extract_lazy_string (py_str
, &type
, &length
, &encoding
);
279 string
= python_string_to_target_python_string (py_str
);
282 output
= PyString_AsString (string
);
283 length
= PyString_Size (string
);
284 type
= builtin_type (gdbarch
)->builtin_char
;
287 gdbpy_print_stack ();
293 if (is_lazy
|| (hint
&& !strcmp (hint
, "string")))
294 LA_PRINT_STRING (stream
, type
, output
, length
, encoding
,
297 fputs_filtered (output
, stream
);
300 gdbpy_print_stack ();
311 else if (replacement
)
313 struct value_print_options opts
= *options
;
315 opts
.addressprint
= 0;
316 common_val_print (replacement
, stream
, recurse
, &opts
, language
);
319 gdbpy_print_stack ();
325 py_restore_tstate (void *p
)
327 PyFrameObject
*frame
= p
;
328 PyThreadState
*tstate
= PyThreadState_GET ();
330 tstate
->frame
= frame
;
333 /* Create a dummy PyFrameObject, needed to work around
334 a Python-2.4 bug with generators. */
336 push_dummy_python_frame ()
338 PyObject
*empty_string
, *null_tuple
, *globals
;
340 PyFrameObject
*frame
;
341 PyThreadState
*tstate
;
343 empty_string
= PyString_FromString ("");
347 null_tuple
= PyTuple_New (0);
350 Py_DECREF (empty_string
);
354 code
= PyCode_New (0, /* argcount */
358 empty_string
, /* code */
359 null_tuple
, /* consts */
360 null_tuple
, /* names */
361 null_tuple
, /* varnames */
362 #if PYTHON_API_VERSION >= 1010
363 null_tuple
, /* freevars */
364 null_tuple
, /* cellvars */
366 empty_string
, /* filename */
367 empty_string
, /* name */
369 empty_string
/* lnotab */
372 Py_DECREF (empty_string
);
373 Py_DECREF (null_tuple
);
378 globals
= PyDict_New ();
385 tstate
= PyThreadState_GET ();
387 frame
= PyFrame_New (tstate
, code
, globals
, NULL
);
395 tstate
->frame
= frame
;
396 make_cleanup (py_restore_tstate
, frame
->f_back
);
397 return (PyObject
*) frame
;
400 /* Helper for apply_val_pretty_printer that formats children of the
401 printer, if any exist. If is_py_none is true, then nothing has
402 been printed by to_string, and format output accordingly. */
404 print_children (PyObject
*printer
, const char *hint
,
405 struct ui_file
*stream
, int recurse
,
406 const struct value_print_options
*options
,
407 const struct language_defn
*language
,
410 int is_map
, is_array
, done_flag
, pretty
;
412 PyObject
*children
, *iter
, *frame
;
413 struct cleanup
*cleanups
;
415 if (! PyObject_HasAttr (printer
, gdbpy_children_cst
))
418 /* If we are printing a map or an array, we want some special
420 is_map
= hint
&& ! strcmp (hint
, "map");
421 is_array
= hint
&& ! strcmp (hint
, "array");
423 children
= PyObject_CallMethodObjArgs (printer
, gdbpy_children_cst
,
427 gdbpy_print_stack ();
431 cleanups
= make_cleanup_py_decref (children
);
433 iter
= PyObject_GetIter (children
);
436 gdbpy_print_stack ();
439 make_cleanup_py_decref (iter
);
441 /* Use the prettyprint_arrays option if we are printing an array,
442 and the pretty option otherwise. */
443 pretty
= is_array
? options
->prettyprint_arrays
: options
->pretty
;
445 /* Manufacture a dummy Python frame to work around Python 2.4 bug,
446 where it insists on having a non-NULL tstate->frame when
447 a generator is called. */
448 frame
= push_dummy_python_frame ();
451 gdbpy_print_stack ();
454 make_cleanup_py_decref (frame
);
457 for (i
= 0; i
< options
->print_max
; ++i
)
459 PyObject
*py_v
, *item
= PyIter_Next (iter
);
461 struct cleanup
*inner_cleanup
;
465 if (PyErr_Occurred ())
466 gdbpy_print_stack ();
467 /* Set a flag so we can know whether we printed all the
468 available elements. */
474 if (! PyArg_ParseTuple (item
, "sO", &name
, &py_v
))
476 gdbpy_print_stack ();
480 inner_cleanup
= make_cleanup_py_decref (item
);
482 /* Print initial "{". For other elements, there are three
484 1. Maps. Print a "," after each value element.
485 2. Arrays. Always print a ",".
486 3. Other. Always print a ",". */
490 fputs_filtered ("{", stream
);
492 fputs_filtered (" = {", stream
);
495 else if (! is_map
|| i
% 2 == 0)
496 fputs_filtered (pretty
? "," : ", ", stream
);
498 /* In summary mode, we just want to print "= {...}" if there is
500 if (options
->summary
)
502 /* This increment tricks the post-loop logic to print what
510 if (! is_map
|| i
% 2 == 0)
514 fputs_filtered ("\n", stream
);
515 print_spaces_filtered (2 + 2 * recurse
, stream
);
518 wrap_here (n_spaces (2 + 2 *recurse
));
521 if (is_map
&& i
% 2 == 0)
522 fputs_filtered ("[", stream
);
525 /* We print the index, not whatever the child method
526 returned as the name. */
527 if (options
->print_array_indexes
)
528 fprintf_filtered (stream
, "[%d] = ", i
);
532 fputs_filtered (name
, stream
);
533 fputs_filtered (" = ", stream
);
536 if (gdbpy_is_lazy_string (py_v
) || gdbpy_is_string (py_v
))
538 gdb_byte
*output
= NULL
;
540 if (gdbpy_is_lazy_string (py_v
))
544 char *encoding
= NULL
;
546 output
= gdbpy_extract_lazy_string (py_v
, &type
,
549 gdbpy_print_stack ();
550 LA_PRINT_STRING (stream
, type
, output
, length
, encoding
,
557 output
= python_string_to_host_string (py_v
);
558 fputs_filtered (output
, stream
);
564 struct value
*value
= convert_value_from_python (py_v
);
568 gdbpy_print_stack ();
569 error (_("Error while executing Python code."));
572 common_val_print (value
, stream
, recurse
+ 1, options
, language
);
575 if (is_map
&& i
% 2 == 0)
576 fputs_filtered ("] = ", stream
);
578 do_cleanups (inner_cleanup
);
587 fputs_filtered ("\n", stream
);
588 print_spaces_filtered (2 + 2 * recurse
, stream
);
590 fputs_filtered ("...", stream
);
594 fputs_filtered ("\n", stream
);
595 print_spaces_filtered (2 * recurse
, stream
);
597 fputs_filtered ("}", stream
);
601 do_cleanups (cleanups
);
605 apply_val_pretty_printer (struct type
*type
, const gdb_byte
*valaddr
,
606 int embedded_offset
, CORE_ADDR address
,
607 struct ui_file
*stream
, int recurse
,
608 const struct value
*val
,
609 const struct value_print_options
*options
,
610 const struct language_defn
*language
)
612 struct gdbarch
*gdbarch
= get_type_arch (type
);
613 PyObject
*printer
= NULL
;
614 PyObject
*val_obj
= NULL
;
617 struct cleanup
*cleanups
;
620 cleanups
= ensure_python_env (gdbarch
, language
);
622 /* Instantiate the printer. */
624 valaddr
+= embedded_offset
;
625 value
= value_from_contents_and_address (type
, valaddr
,
626 address
+ embedded_offset
);
629 set_value_component_location (value
, val
);
630 /* set_value_component_location resets the address, so we may
631 need to set it again. */
632 if (VALUE_LVAL (value
) != lval_internalvar
633 && VALUE_LVAL (value
) != lval_internalvar_component
634 && VALUE_LVAL (value
) != lval_computed
)
635 set_value_address (value
, address
+ embedded_offset
);
638 val_obj
= value_to_value_object (value
);
642 /* Find the constructor. */
643 printer
= find_pretty_printer (val_obj
);
645 make_cleanup_py_decref (printer
);
646 if (! printer
|| printer
== Py_None
)
649 /* If we are printing a map, we want some special formatting. */
650 hint
= gdbpy_get_display_hint (printer
);
651 make_cleanup (free_current_contents
, &hint
);
653 /* Print the section */
654 is_py_none
= print_string_repr (printer
, hint
, stream
, recurse
,
655 options
, language
, gdbarch
);
656 print_children (printer
, hint
, stream
, recurse
, options
, language
,
663 if (PyErr_Occurred ())
664 gdbpy_print_stack ();
665 do_cleanups (cleanups
);
670 /* Apply a pretty-printer for the varobj code. PRINTER_OBJ is the
671 print object. It must have a 'to_string' method (but this is
672 checked by varobj, not here) which takes no arguments and
673 returns a string. The printer will return a value and in the case
674 of a Python string being returned, this function will return a
675 PyObject containing the string. For any other type, *REPLACEMENT is
676 set to the replacement value and this function returns NULL. On
677 error, *REPLACEMENT is set to NULL and this function also returns
680 apply_varobj_pretty_printer (PyObject
*printer_obj
,
681 struct value
**replacement
)
683 PyObject
*py_str
= NULL
;
686 py_str
= pretty_print_one_value (printer_obj
, replacement
);
688 if (*replacement
== NULL
&& py_str
== NULL
)
689 gdbpy_print_stack ();
694 /* Find a pretty-printer object for the varobj module. Returns a new
695 reference to the object if successful; returns NULL if not. VALUE
696 is the value for which a printer tests to determine if it
697 can pretty-print the value. */
699 gdbpy_get_varobj_pretty_printer (struct value
*value
)
702 PyObject
*pretty_printer
= NULL
;
703 volatile struct gdb_exception except
;
705 TRY_CATCH (except
, RETURN_MASK_ALL
)
707 value
= value_copy (value
);
709 GDB_PY_HANDLE_EXCEPTION (except
);
711 val_obj
= value_to_value_object (value
);
715 pretty_printer
= find_pretty_printer (val_obj
);
717 return pretty_printer
;
720 /* A Python function which wraps find_pretty_printer and instantiates
721 the resulting class. This accepts a Value argument and returns a
722 pretty printer instance, or None. This function is useful as an
723 argument to the MI command -var-set-visualizer. */
725 gdbpy_default_visualizer (PyObject
*self
, PyObject
*args
)
731 if (! PyArg_ParseTuple (args
, "O", &val_obj
))
733 value
= value_object_to_value (val_obj
);
736 PyErr_SetString (PyExc_TypeError
,
737 _("Argument must be a gdb.Value."));
741 cons
= find_pretty_printer (val_obj
);
745 #else /* HAVE_PYTHON */
748 apply_val_pretty_printer (struct type
*type
, const gdb_byte
*valaddr
,
749 int embedded_offset
, CORE_ADDR address
,
750 struct ui_file
*stream
, int recurse
,
751 const struct value
*val
,
752 const struct value_print_options
*options
,
753 const struct language_defn
*language
)
758 #endif /* HAVE_PYTHON */