1 /* Implementation of the GDB variable objects API.
3 Copyright (C) 1999-2017 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "expression.h"
26 #include "gdb_regex.h"
30 #include "gdbthread.h"
32 #include "varobj-iter.h"
35 #include "python/python.h"
36 #include "python/python-internal.h"
37 #include "python/py-ref.h"
42 /* Non-zero if we want to see trace of varobj level stuff. */
44 unsigned int varobjdebug = 0;
46 show_varobjdebug (struct ui_file *file, int from_tty,
47 struct cmd_list_element *c, const char *value)
49 fprintf_filtered (file, _("Varobj debugging is %s.\n"), value);
52 /* String representations of gdb's format codes. */
53 char *varobj_format_string[] =
54 { "natural", "binary", "decimal", "hexadecimal", "octal", "zero-hexadecimal" };
56 /* True if we want to allow Python-based pretty-printing. */
57 static int pretty_printing = 0;
60 varobj_enable_pretty_printing (void)
67 /* Every root variable has one of these structures saved in its
72 /* The expression for this parent. */
75 /* Block for which this expression is valid. */
76 const struct block *valid_block;
78 /* The frame for this expression. This field is set iff valid_block is
80 struct frame_id frame;
82 /* The global thread ID that this varobj_root belongs to. This field
83 is only valid if valid_block is not NULL.
84 When not 0, indicates which thread 'frame' belongs to.
85 When 0, indicates that the thread list was empty when the varobj_root
89 /* If 1, the -var-update always recomputes the value in the
90 current thread and frame. Otherwise, variable object is
91 always updated in the specific scope/thread/frame. */
94 /* Flag that indicates validity: set to 0 when this varobj_root refers
95 to symbols that do not exist anymore. */
98 /* Language-related operations for this variable and its
100 const struct lang_varobj_ops *lang_ops;
102 /* The varobj for this root node. */
103 struct varobj *rootvar;
105 /* Next root variable */
106 struct varobj_root *next;
109 /* Dynamic part of varobj. */
111 struct varobj_dynamic
113 /* Whether the children of this varobj were requested. This field is
114 used to decide if dynamic varobj should recompute their children.
115 In the event that the frontend never asked for the children, we
117 int children_requested;
119 /* The pretty-printer constructor. If NULL, then the default
120 pretty-printer will be looked up. If None, then no
121 pretty-printer will be installed. */
122 PyObject *constructor;
124 /* The pretty-printer that has been constructed. If NULL, then a
125 new printer object is needed, and one will be constructed. */
126 PyObject *pretty_printer;
128 /* The iterator returned by the printer's 'children' method, or NULL
130 struct varobj_iter *child_iter;
132 /* We request one extra item from the iterator, so that we can
133 report to the caller whether there are more items than we have
134 already reported. However, we don't want to install this value
135 when we read it, because that will mess up future updates. So,
136 we stash it here instead. */
137 varobj_item *saved_item;
140 /* A list of varobjs */
148 /* Private function prototypes */
150 /* Helper functions for the above subcommands. */
152 static int delete_variable (struct varobj *, int);
154 static void delete_variable_1 (int *, struct varobj *, int, int);
156 static int install_variable (struct varobj *);
158 static void uninstall_variable (struct varobj *);
160 static struct varobj *create_child (struct varobj *, int, std::string &);
162 static struct varobj *
163 create_child_with_value (struct varobj *parent, int index,
164 struct varobj_item *item);
166 /* Utility routines */
168 static struct varobj *new_variable (void);
170 static struct varobj *new_root_variable (void);
172 static void free_variable (struct varobj *var);
174 static struct cleanup *make_cleanup_free_variable (struct varobj *var);
176 static enum varobj_display_formats variable_default_display (struct varobj *);
178 static int update_type_if_necessary (struct varobj *var,
179 struct value *new_value);
181 static int install_new_value (struct varobj *var, struct value *value,
184 /* Language-specific routines. */
186 static int number_of_children (const struct varobj *);
188 static std::string name_of_variable (const struct varobj *);
190 static std::string name_of_child (struct varobj *, int);
192 static struct value *value_of_root (struct varobj **var_handle, int *);
194 static struct value *value_of_child (const struct varobj *parent, int index);
196 static std::string my_value_of_variable (struct varobj *var,
197 enum varobj_display_formats format);
199 static int is_root_p (const struct varobj *var);
201 static struct varobj *varobj_add_child (struct varobj *var,
202 struct varobj_item *item);
206 /* Mappings of varobj_display_formats enums to gdb's format codes. */
207 static int format_code[] = { 0, 't', 'd', 'x', 'o', 'z' };
209 /* Header of the list of root variable objects. */
210 static struct varobj_root *rootlist;
212 /* Prime number indicating the number of buckets in the hash table. */
213 /* A prime large enough to avoid too many collisions. */
214 #define VAROBJ_TABLE_SIZE 227
216 /* Pointer to the varobj hash table (built at run time). */
217 static struct vlist **varobj_table;
221 /* API Implementation */
223 is_root_p (const struct varobj *var)
225 return (var->root->rootvar == var);
229 /* Helper function to install a Python environment suitable for
230 use during operations on VAR. */
232 varobj_ensure_python_env (const struct varobj *var)
234 return ensure_python_env (var->root->exp->gdbarch,
235 var->root->exp->language_defn);
238 /* See python-internal.h. */
239 gdbpy_enter_varobj::gdbpy_enter_varobj (const struct varobj *var)
240 : gdbpy_enter (var->root->exp->gdbarch, var->root->exp->language_defn)
246 /* Return the full FRAME which corresponds to the given CORE_ADDR
247 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
249 static struct frame_info *
250 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr)
252 struct frame_info *frame = NULL;
254 if (frame_addr == (CORE_ADDR) 0)
257 for (frame = get_current_frame ();
259 frame = get_prev_frame (frame))
261 /* The CORE_ADDR we get as argument was parsed from a string GDB
262 output as $fp. This output got truncated to gdbarch_addr_bit.
263 Truncate the frame base address in the same manner before
264 comparing it against our argument. */
265 CORE_ADDR frame_base = get_frame_base_address (frame);
266 int addr_bit = gdbarch_addr_bit (get_frame_arch (frame));
268 if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
269 frame_base &= ((CORE_ADDR) 1 << addr_bit) - 1;
271 if (frame_base == frame_addr)
278 /* Creates a varobj (not its children). */
281 varobj_create (const char *objname,
282 const char *expression, CORE_ADDR frame, enum varobj_type type)
285 struct cleanup *old_chain;
287 /* Fill out a varobj structure for the (root) variable being constructed. */
288 var = new_root_variable ();
289 old_chain = make_cleanup_free_variable (var);
291 if (expression != NULL)
293 struct frame_info *fi;
294 struct frame_id old_id = null_frame_id;
295 const struct block *block;
297 struct value *value = NULL;
300 /* Parse and evaluate the expression, filling in as much of the
301 variable's data as possible. */
303 if (has_stack_frames ())
305 /* Allow creator to specify context of variable. */
306 if ((type == USE_CURRENT_FRAME) || (type == USE_SELECTED_FRAME))
307 fi = get_selected_frame (NULL);
309 /* FIXME: cagney/2002-11-23: This code should be doing a
310 lookup using the frame ID and not just the frame's
311 ``address''. This, of course, means an interface
312 change. However, with out that interface change ISAs,
313 such as the ia64 with its two stacks, won't work.
314 Similar goes for the case where there is a frameless
316 fi = find_frame_addr_in_frame_chain (frame);
321 /* frame = -2 means always use selected frame. */
322 if (type == USE_SELECTED_FRAME)
323 var->root->floating = 1;
329 block = get_frame_block (fi, 0);
330 pc = get_frame_pc (fi);
334 innermost_block = NULL;
335 /* Wrap the call to parse expression, so we can
336 return a sensible error. */
339 var->root->exp = parse_exp_1 (&p, pc, block, 0);
342 CATCH (except, RETURN_MASK_ERROR)
344 do_cleanups (old_chain);
349 /* Don't allow variables to be created for types. */
350 if (var->root->exp->elts[0].opcode == OP_TYPE
351 || var->root->exp->elts[0].opcode == OP_TYPEOF
352 || var->root->exp->elts[0].opcode == OP_DECLTYPE)
354 do_cleanups (old_chain);
355 fprintf_unfiltered (gdb_stderr, "Attempt to use a type name"
356 " as an expression.\n");
360 var->format = variable_default_display (var);
361 var->root->valid_block = innermost_block;
362 var->name = expression;
363 /* For a root var, the name and the expr are the same. */
364 var->path_expr = expression;
366 /* When the frame is different from the current frame,
367 we must select the appropriate frame before parsing
368 the expression, otherwise the value will not be current.
369 Since select_frame is so benign, just call it for all cases. */
372 /* User could specify explicit FRAME-ADDR which was not found but
373 EXPRESSION is frame specific and we would not be able to evaluate
374 it correctly next time. With VALID_BLOCK set we must also set
375 FRAME and THREAD_ID. */
377 error (_("Failed to find the specified frame"));
379 var->root->frame = get_frame_id (fi);
380 var->root->thread_id = ptid_to_global_thread_id (inferior_ptid);
381 old_id = get_frame_id (get_selected_frame (NULL));
385 /* We definitely need to catch errors here.
386 If evaluate_expression succeeds we got the value we wanted.
387 But if it fails, we still go on with a call to evaluate_type(). */
390 value = evaluate_expression (var->root->exp.get ());
392 CATCH (except, RETURN_MASK_ERROR)
394 /* Error getting the value. Try to at least get the
396 struct value *type_only_value = evaluate_type (var->root->exp.get ());
398 var->type = value_type (type_only_value);
404 int real_type_found = 0;
406 var->type = value_actual_type (value, 0, &real_type_found);
408 value = value_cast (var->type, value);
411 /* Set language info */
412 var->root->lang_ops = var->root->exp->language_defn->la_varobj_ops;
414 install_new_value (var, value, 1 /* Initial assignment */);
416 /* Set ourselves as our root. */
417 var->root->rootvar = var;
419 /* Reset the selected frame. */
420 if (frame_id_p (old_id))
421 select_frame (frame_find_by_id (old_id));
424 /* If the variable object name is null, that means this
425 is a temporary variable, so don't install it. */
427 if ((var != NULL) && (objname != NULL))
429 var->obj_name = objname;
431 /* If a varobj name is duplicated, the install will fail so
433 if (!install_variable (var))
435 do_cleanups (old_chain);
440 discard_cleanups (old_chain);
444 /* Generates an unique name that can be used for a varobj. */
447 varobj_gen_name (void)
452 /* Generate a name for this object. */
454 obj_name = xstrprintf ("var%d", id);
459 /* Given an OBJNAME, returns the pointer to the corresponding varobj. Call
460 error if OBJNAME cannot be found. */
463 varobj_get_handle (const char *objname)
467 unsigned int index = 0;
470 for (chp = objname; *chp; chp++)
472 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
475 cv = *(varobj_table + index);
476 while (cv != NULL && cv->var->obj_name != objname)
480 error (_("Variable object not found"));
485 /* Given the handle, return the name of the object. */
488 varobj_get_objname (const struct varobj *var)
490 return var->obj_name.c_str ();
493 /* Given the handle, return the expression represented by the
497 varobj_get_expression (const struct varobj *var)
499 return name_of_variable (var);
505 varobj_delete (struct varobj *var, int only_children)
507 return delete_variable (var, only_children);
512 /* Convenience function for varobj_set_visualizer. Instantiate a
513 pretty-printer for a given value. */
515 instantiate_pretty_printer (PyObject *constructor, struct value *value)
517 PyObject *val_obj = NULL;
520 val_obj = value_to_value_object (value);
524 printer = PyObject_CallFunctionObjArgs (constructor, val_obj, NULL);
531 /* Set/Get variable object display format. */
533 enum varobj_display_formats
534 varobj_set_display_format (struct varobj *var,
535 enum varobj_display_formats format)
542 case FORMAT_HEXADECIMAL:
544 case FORMAT_ZHEXADECIMAL:
545 var->format = format;
549 var->format = variable_default_display (var);
552 if (varobj_value_is_changeable_p (var)
553 && var->value && !value_lazy (var->value))
555 var->print_value = varobj_value_get_print_value (var->value,
562 enum varobj_display_formats
563 varobj_get_display_format (const struct varobj *var)
568 gdb::unique_xmalloc_ptr<char>
569 varobj_get_display_hint (const struct varobj *var)
571 gdb::unique_xmalloc_ptr<char> result;
574 if (!gdb_python_initialized)
577 gdbpy_enter_varobj enter_py (var);
579 if (var->dynamic->pretty_printer != NULL)
580 result = gdbpy_get_display_hint (var->dynamic->pretty_printer);
586 /* Return true if the varobj has items after TO, false otherwise. */
589 varobj_has_more (const struct varobj *var, int to)
591 if (VEC_length (varobj_p, var->children) > to)
593 return ((to == -1 || VEC_length (varobj_p, var->children) == to)
594 && (var->dynamic->saved_item != NULL));
597 /* If the variable object is bound to a specific thread, that
598 is its evaluation can always be done in context of a frame
599 inside that thread, returns GDB id of the thread -- which
600 is always positive. Otherwise, returns -1. */
602 varobj_get_thread_id (const struct varobj *var)
604 if (var->root->valid_block && var->root->thread_id > 0)
605 return var->root->thread_id;
611 varobj_set_frozen (struct varobj *var, int frozen)
613 /* When a variable is unfrozen, we don't fetch its value.
614 The 'not_fetched' flag remains set, so next -var-update
617 We don't fetch the value, because for structures the client
618 should do -var-update anyway. It would be bad to have different
619 client-size logic for structure and other types. */
620 var->frozen = frozen;
624 varobj_get_frozen (const struct varobj *var)
629 /* A helper function that restricts a range to what is actually
630 available in a VEC. This follows the usual rules for the meaning
631 of FROM and TO -- if either is negative, the entire range is
635 varobj_restrict_range (VEC (varobj_p) *children, int *from, int *to)
637 if (*from < 0 || *to < 0)
640 *to = VEC_length (varobj_p, children);
644 if (*from > VEC_length (varobj_p, children))
645 *from = VEC_length (varobj_p, children);
646 if (*to > VEC_length (varobj_p, children))
647 *to = VEC_length (varobj_p, children);
653 /* A helper for update_dynamic_varobj_children that installs a new
654 child when needed. */
657 install_dynamic_child (struct varobj *var,
658 VEC (varobj_p) **changed,
659 VEC (varobj_p) **type_changed,
660 VEC (varobj_p) **newobj,
661 VEC (varobj_p) **unchanged,
664 struct varobj_item *item)
666 if (VEC_length (varobj_p, var->children) < index + 1)
668 /* There's no child yet. */
669 struct varobj *child = varobj_add_child (var, item);
673 VEC_safe_push (varobj_p, *newobj, child);
679 varobj_p existing = VEC_index (varobj_p, var->children, index);
680 int type_updated = update_type_if_necessary (existing, item->value);
685 VEC_safe_push (varobj_p, *type_changed, existing);
687 if (install_new_value (existing, item->value, 0))
689 if (!type_updated && changed)
690 VEC_safe_push (varobj_p, *changed, existing);
692 else if (!type_updated && unchanged)
693 VEC_safe_push (varobj_p, *unchanged, existing);
700 dynamic_varobj_has_child_method (const struct varobj *var)
702 PyObject *printer = var->dynamic->pretty_printer;
704 if (!gdb_python_initialized)
707 gdbpy_enter_varobj enter_py (var);
708 return PyObject_HasAttr (printer, gdbpy_children_cst);
712 /* A factory for creating dynamic varobj's iterators. Returns an
713 iterator object suitable for iterating over VAR's children. */
715 static struct varobj_iter *
716 varobj_get_iterator (struct varobj *var)
719 if (var->dynamic->pretty_printer)
720 return py_varobj_get_iterator (var, var->dynamic->pretty_printer);
723 gdb_assert_not_reached (_("\
724 requested an iterator from a non-dynamic varobj"));
727 /* Release and clear VAR's saved item, if any. */
730 varobj_clear_saved_item (struct varobj_dynamic *var)
732 if (var->saved_item != NULL)
734 value_free (var->saved_item->value);
735 xfree (var->saved_item);
736 var->saved_item = NULL;
741 update_dynamic_varobj_children (struct varobj *var,
742 VEC (varobj_p) **changed,
743 VEC (varobj_p) **type_changed,
744 VEC (varobj_p) **newobj,
745 VEC (varobj_p) **unchanged,
755 if (update_children || var->dynamic->child_iter == NULL)
757 varobj_iter_delete (var->dynamic->child_iter);
758 var->dynamic->child_iter = varobj_get_iterator (var);
760 varobj_clear_saved_item (var->dynamic);
764 if (var->dynamic->child_iter == NULL)
768 i = VEC_length (varobj_p, var->children);
770 /* We ask for one extra child, so that MI can report whether there
771 are more children. */
772 for (; to < 0 || i < to + 1; ++i)
776 /* See if there was a leftover from last time. */
777 if (var->dynamic->saved_item != NULL)
779 item = var->dynamic->saved_item;
780 var->dynamic->saved_item = NULL;
784 item = varobj_iter_next (var->dynamic->child_iter);
785 /* Release vitem->value so its lifetime is not bound to the
786 execution of a command. */
787 if (item != NULL && item->value != NULL)
788 release_value_or_incref (item->value);
793 /* Iteration is done. Remove iterator from VAR. */
794 varobj_iter_delete (var->dynamic->child_iter);
795 var->dynamic->child_iter = NULL;
798 /* We don't want to push the extra child on any report list. */
799 if (to < 0 || i < to)
801 int can_mention = from < 0 || i >= from;
803 install_dynamic_child (var, can_mention ? changed : NULL,
804 can_mention ? type_changed : NULL,
805 can_mention ? newobj : NULL,
806 can_mention ? unchanged : NULL,
807 can_mention ? cchanged : NULL, i,
814 var->dynamic->saved_item = item;
816 /* We want to truncate the child list just before this
822 if (i < VEC_length (varobj_p, var->children))
827 for (j = i; j < VEC_length (varobj_p, var->children); ++j)
828 varobj_delete (VEC_index (varobj_p, var->children, j), 0);
829 VEC_truncate (varobj_p, var->children, i);
832 /* If there are fewer children than requested, note that the list of
834 if (to >= 0 && VEC_length (varobj_p, var->children) < to)
837 var->num_children = VEC_length (varobj_p, var->children);
843 varobj_get_num_children (struct varobj *var)
845 if (var->num_children == -1)
847 if (varobj_is_dynamic_p (var))
851 /* If we have a dynamic varobj, don't report -1 children.
852 So, try to fetch some children first. */
853 update_dynamic_varobj_children (var, NULL, NULL, NULL, NULL, &dummy,
857 var->num_children = number_of_children (var);
860 return var->num_children >= 0 ? var->num_children : 0;
863 /* Creates a list of the immediate children of a variable object;
864 the return code is the number of such children or -1 on error. */
867 varobj_list_children (struct varobj *var, int *from, int *to)
869 int i, children_changed;
871 var->dynamic->children_requested = 1;
873 if (varobj_is_dynamic_p (var))
875 /* This, in theory, can result in the number of children changing without
876 frontend noticing. But well, calling -var-list-children on the same
877 varobj twice is not something a sane frontend would do. */
878 update_dynamic_varobj_children (var, NULL, NULL, NULL, NULL,
879 &children_changed, 0, 0, *to);
880 varobj_restrict_range (var->children, from, to);
881 return var->children;
884 if (var->num_children == -1)
885 var->num_children = number_of_children (var);
887 /* If that failed, give up. */
888 if (var->num_children == -1)
889 return var->children;
891 /* If we're called when the list of children is not yet initialized,
892 allocate enough elements in it. */
893 while (VEC_length (varobj_p, var->children) < var->num_children)
894 VEC_safe_push (varobj_p, var->children, NULL);
896 for (i = 0; i < var->num_children; i++)
898 varobj_p existing = VEC_index (varobj_p, var->children, i);
900 if (existing == NULL)
902 /* Either it's the first call to varobj_list_children for
903 this variable object, and the child was never created,
904 or it was explicitly deleted by the client. */
905 std::string name = name_of_child (var, i);
906 existing = create_child (var, i, name);
907 VEC_replace (varobj_p, var->children, i, existing);
911 varobj_restrict_range (var->children, from, to);
912 return var->children;
915 static struct varobj *
916 varobj_add_child (struct varobj *var, struct varobj_item *item)
918 varobj_p v = create_child_with_value (var,
919 VEC_length (varobj_p, var->children),
922 VEC_safe_push (varobj_p, var->children, v);
926 /* Obtain the type of an object Variable as a string similar to the one gdb
927 prints on the console. The caller is responsible for freeing the string.
931 varobj_get_type (struct varobj *var)
933 /* For the "fake" variables, do not return a type. (Its type is
935 Do not return a type for invalid variables as well. */
936 if (CPLUS_FAKE_CHILD (var) || !var->root->is_valid)
937 return std::string ();
939 return type_to_string (var->type);
942 /* Obtain the type of an object variable. */
945 varobj_get_gdb_type (const struct varobj *var)
950 /* Is VAR a path expression parent, i.e., can it be used to construct
951 a valid path expression? */
954 is_path_expr_parent (const struct varobj *var)
956 gdb_assert (var->root->lang_ops->is_path_expr_parent != NULL);
957 return var->root->lang_ops->is_path_expr_parent (var);
960 /* Is VAR a path expression parent, i.e., can it be used to construct
961 a valid path expression? By default we assume any VAR can be a path
965 varobj_default_is_path_expr_parent (const struct varobj *var)
970 /* Return the path expression parent for VAR. */
972 const struct varobj *
973 varobj_get_path_expr_parent (const struct varobj *var)
975 const struct varobj *parent = var;
977 while (!is_root_p (parent) && !is_path_expr_parent (parent))
978 parent = parent->parent;
983 /* Return a pointer to the full rooted expression of varobj VAR.
984 If it has not been computed yet, compute it. */
987 varobj_get_path_expr (const struct varobj *var)
989 if (var->path_expr.empty ())
991 /* For root varobjs, we initialize path_expr
992 when creating varobj, so here it should be
994 struct varobj *mutable_var = (struct varobj *) var;
995 gdb_assert (!is_root_p (var));
997 mutable_var->path_expr = (*var->root->lang_ops->path_expr_of_child) (var);
1000 return var->path_expr.c_str ();
1003 const struct language_defn *
1004 varobj_get_language (const struct varobj *var)
1006 return var->root->exp->language_defn;
1010 varobj_get_attributes (const struct varobj *var)
1014 if (varobj_editable_p (var))
1015 /* FIXME: define masks for attributes. */
1016 attributes |= 0x00000001; /* Editable */
1021 /* Return true if VAR is a dynamic varobj. */
1024 varobj_is_dynamic_p (const struct varobj *var)
1026 return var->dynamic->pretty_printer != NULL;
1030 varobj_get_formatted_value (struct varobj *var,
1031 enum varobj_display_formats format)
1033 return my_value_of_variable (var, format);
1037 varobj_get_value (struct varobj *var)
1039 return my_value_of_variable (var, var->format);
1042 /* Set the value of an object variable (if it is editable) to the
1043 value of the given expression. */
1044 /* Note: Invokes functions that can call error(). */
1047 varobj_set_value (struct varobj *var, const char *expression)
1049 struct value *val = NULL; /* Initialize to keep gcc happy. */
1050 /* The argument "expression" contains the variable's new value.
1051 We need to first construct a legal expression for this -- ugh! */
1052 /* Does this cover all the bases? */
1053 struct value *value = NULL; /* Initialize to keep gcc happy. */
1054 int saved_input_radix = input_radix;
1055 const char *s = expression;
1057 gdb_assert (varobj_editable_p (var));
1059 input_radix = 10; /* ALWAYS reset to decimal temporarily. */
1060 expression_up exp = parse_exp_1 (&s, 0, 0, 0);
1063 value = evaluate_expression (exp.get ());
1066 CATCH (except, RETURN_MASK_ERROR)
1068 /* We cannot proceed without a valid expression. */
1073 /* All types that are editable must also be changeable. */
1074 gdb_assert (varobj_value_is_changeable_p (var));
1076 /* The value of a changeable variable object must not be lazy. */
1077 gdb_assert (!value_lazy (var->value));
1079 /* Need to coerce the input. We want to check if the
1080 value of the variable object will be different
1081 after assignment, and the first thing value_assign
1082 does is coerce the input.
1083 For example, if we are assigning an array to a pointer variable we
1084 should compare the pointer with the array's address, not with the
1086 value = coerce_array (value);
1088 /* The new value may be lazy. value_assign, or
1089 rather value_contents, will take care of this. */
1092 val = value_assign (var->value, value);
1095 CATCH (except, RETURN_MASK_ERROR)
1101 /* If the value has changed, record it, so that next -var-update can
1102 report this change. If a variable had a value of '1', we've set it
1103 to '333' and then set again to '1', when -var-update will report this
1104 variable as changed -- because the first assignment has set the
1105 'updated' flag. There's no need to optimize that, because return value
1106 of -var-update should be considered an approximation. */
1107 var->updated = install_new_value (var, val, 0 /* Compare values. */);
1108 input_radix = saved_input_radix;
1114 /* A helper function to install a constructor function and visualizer
1115 in a varobj_dynamic. */
1118 install_visualizer (struct varobj_dynamic *var, PyObject *constructor,
1119 PyObject *visualizer)
1121 Py_XDECREF (var->constructor);
1122 var->constructor = constructor;
1124 Py_XDECREF (var->pretty_printer);
1125 var->pretty_printer = visualizer;
1127 varobj_iter_delete (var->child_iter);
1128 var->child_iter = NULL;
1131 /* Install the default visualizer for VAR. */
1134 install_default_visualizer (struct varobj *var)
1136 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1137 if (CPLUS_FAKE_CHILD (var))
1140 if (pretty_printing)
1142 PyObject *pretty_printer = NULL;
1146 pretty_printer = gdbpy_get_varobj_pretty_printer (var->value);
1147 if (! pretty_printer)
1149 gdbpy_print_stack ();
1150 error (_("Cannot instantiate printer for default visualizer"));
1154 if (pretty_printer == Py_None)
1156 Py_DECREF (pretty_printer);
1157 pretty_printer = NULL;
1160 install_visualizer (var->dynamic, NULL, pretty_printer);
1164 /* Instantiate and install a visualizer for VAR using CONSTRUCTOR to
1165 make a new object. */
1168 construct_visualizer (struct varobj *var, PyObject *constructor)
1170 PyObject *pretty_printer;
1172 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1173 if (CPLUS_FAKE_CHILD (var))
1176 Py_INCREF (constructor);
1177 if (constructor == Py_None)
1178 pretty_printer = NULL;
1181 pretty_printer = instantiate_pretty_printer (constructor, var->value);
1182 if (! pretty_printer)
1184 gdbpy_print_stack ();
1185 Py_DECREF (constructor);
1186 constructor = Py_None;
1187 Py_INCREF (constructor);
1190 if (pretty_printer == Py_None)
1192 Py_DECREF (pretty_printer);
1193 pretty_printer = NULL;
1197 install_visualizer (var->dynamic, constructor, pretty_printer);
1200 #endif /* HAVE_PYTHON */
1202 /* A helper function for install_new_value. This creates and installs
1203 a visualizer for VAR, if appropriate. */
1206 install_new_value_visualizer (struct varobj *var)
1209 /* If the constructor is None, then we want the raw value. If VAR
1210 does not have a value, just skip this. */
1211 if (!gdb_python_initialized)
1214 if (var->dynamic->constructor != Py_None && var->value != NULL)
1216 gdbpy_enter_varobj enter_py (var);
1218 if (var->dynamic->constructor == NULL)
1219 install_default_visualizer (var);
1221 construct_visualizer (var, var->dynamic->constructor);
1228 /* When using RTTI to determine variable type it may be changed in runtime when
1229 the variable value is changed. This function checks whether type of varobj
1230 VAR will change when a new value NEW_VALUE is assigned and if it is so
1231 updates the type of VAR. */
1234 update_type_if_necessary (struct varobj *var, struct value *new_value)
1238 struct value_print_options opts;
1240 get_user_print_options (&opts);
1241 if (opts.objectprint)
1243 struct type *new_type = value_actual_type (new_value, 0, 0);
1244 std::string new_type_str = type_to_string (new_type);
1245 std::string curr_type_str = varobj_get_type (var);
1247 /* Did the type name change? */
1248 if (curr_type_str != new_type_str)
1250 var->type = new_type;
1252 /* This information may be not valid for a new type. */
1253 varobj_delete (var, 1);
1254 VEC_free (varobj_p, var->children);
1255 var->num_children = -1;
1264 /* Assign a new value to a variable object. If INITIAL is non-zero,
1265 this is the first assignement after the variable object was just
1266 created, or changed type. In that case, just assign the value
1268 Otherwise, assign the new value, and return 1 if the value is
1269 different from the current one, 0 otherwise. The comparison is
1270 done on textual representation of value. Therefore, some types
1271 need not be compared. E.g. for structures the reported value is
1272 always "{...}", so no comparison is necessary here. If the old
1273 value was NULL and new one is not, or vice versa, we always return 1.
1275 The VALUE parameter should not be released -- the function will
1276 take care of releasing it when needed. */
1278 install_new_value (struct varobj *var, struct value *value, int initial)
1283 int intentionally_not_fetched = 0;
1285 /* We need to know the varobj's type to decide if the value should
1286 be fetched or not. C++ fake children (public/protected/private)
1287 don't have a type. */
1288 gdb_assert (var->type || CPLUS_FAKE_CHILD (var));
1289 changeable = varobj_value_is_changeable_p (var);
1291 /* If the type has custom visualizer, we consider it to be always
1292 changeable. FIXME: need to make sure this behaviour will not
1293 mess up read-sensitive values. */
1294 if (var->dynamic->pretty_printer != NULL)
1297 need_to_fetch = changeable;
1299 /* We are not interested in the address of references, and given
1300 that in C++ a reference is not rebindable, it cannot
1301 meaningfully change. So, get hold of the real value. */
1303 value = coerce_ref (value);
1305 if (var->type && TYPE_CODE (var->type) == TYPE_CODE_UNION)
1306 /* For unions, we need to fetch the value implicitly because
1307 of implementation of union member fetch. When gdb
1308 creates a value for a field and the value of the enclosing
1309 structure is not lazy, it immediately copies the necessary
1310 bytes from the enclosing values. If the enclosing value is
1311 lazy, the call to value_fetch_lazy on the field will read
1312 the data from memory. For unions, that means we'll read the
1313 same memory more than once, which is not desirable. So
1317 /* The new value might be lazy. If the type is changeable,
1318 that is we'll be comparing values of this type, fetch the
1319 value now. Otherwise, on the next update the old value
1320 will be lazy, which means we've lost that old value. */
1321 if (need_to_fetch && value && value_lazy (value))
1323 const struct varobj *parent = var->parent;
1324 int frozen = var->frozen;
1326 for (; !frozen && parent; parent = parent->parent)
1327 frozen |= parent->frozen;
1329 if (frozen && initial)
1331 /* For variables that are frozen, or are children of frozen
1332 variables, we don't do fetch on initial assignment.
1333 For non-initial assignemnt we do the fetch, since it means we're
1334 explicitly asked to compare the new value with the old one. */
1335 intentionally_not_fetched = 1;
1342 value_fetch_lazy (value);
1345 CATCH (except, RETURN_MASK_ERROR)
1347 /* Set the value to NULL, so that for the next -var-update,
1348 we don't try to compare the new value with this value,
1349 that we couldn't even read. */
1356 /* Get a reference now, before possibly passing it to any Python
1357 code that might release it. */
1359 value_incref (value);
1361 /* Below, we'll be comparing string rendering of old and new
1362 values. Don't get string rendering if the value is
1363 lazy -- if it is, the code above has decided that the value
1364 should not be fetched. */
1365 std::string print_value;
1366 if (value != NULL && !value_lazy (value)
1367 && var->dynamic->pretty_printer == NULL)
1368 print_value = varobj_value_get_print_value (value, var->format, var);
1370 /* If the type is changeable, compare the old and the new values.
1371 If this is the initial assignment, we don't have any old value
1373 if (!initial && changeable)
1375 /* If the value of the varobj was changed by -var-set-value,
1376 then the value in the varobj and in the target is the same.
1377 However, that value is different from the value that the
1378 varobj had after the previous -var-update. So need to the
1379 varobj as changed. */
1384 else if (var->dynamic->pretty_printer == NULL)
1386 /* Try to compare the values. That requires that both
1387 values are non-lazy. */
1388 if (var->not_fetched && value_lazy (var->value))
1390 /* This is a frozen varobj and the value was never read.
1391 Presumably, UI shows some "never read" indicator.
1392 Now that we've fetched the real value, we need to report
1393 this varobj as changed so that UI can show the real
1397 else if (var->value == NULL && value == NULL)
1400 else if (var->value == NULL || value == NULL)
1406 gdb_assert (!value_lazy (var->value));
1407 gdb_assert (!value_lazy (value));
1409 gdb_assert (!var->print_value.empty () && !print_value.empty ());
1410 if (var->print_value != print_value)
1416 if (!initial && !changeable)
1418 /* For values that are not changeable, we don't compare the values.
1419 However, we want to notice if a value was not NULL and now is NULL,
1420 or vise versa, so that we report when top-level varobjs come in scope
1421 and leave the scope. */
1422 changed = (var->value != NULL) != (value != NULL);
1425 /* We must always keep the new value, since children depend on it. */
1426 if (var->value != NULL && var->value != value)
1427 value_free (var->value);
1429 if (value && value_lazy (value) && intentionally_not_fetched)
1430 var->not_fetched = 1;
1432 var->not_fetched = 0;
1435 install_new_value_visualizer (var);
1437 /* If we installed a pretty-printer, re-compare the printed version
1438 to see if the variable changed. */
1439 if (var->dynamic->pretty_printer != NULL)
1441 print_value = varobj_value_get_print_value (var->value, var->format,
1443 if ((var->print_value.empty () && !print_value.empty ())
1444 || (!var->print_value.empty () && print_value.empty ())
1445 || (!var->print_value.empty () && !print_value.empty ()
1446 && var->print_value != print_value))
1449 var->print_value = print_value;
1451 gdb_assert (!var->value || value_type (var->value));
1456 /* Return the requested range for a varobj. VAR is the varobj. FROM
1457 and TO are out parameters; *FROM and *TO will be set to the
1458 selected sub-range of VAR. If no range was selected using
1459 -var-set-update-range, then both will be -1. */
1461 varobj_get_child_range (const struct varobj *var, int *from, int *to)
1467 /* Set the selected sub-range of children of VAR to start at index
1468 FROM and end at index TO. If either FROM or TO is less than zero,
1469 this is interpreted as a request for all children. */
1471 varobj_set_child_range (struct varobj *var, int from, int to)
1478 varobj_set_visualizer (struct varobj *var, const char *visualizer)
1483 if (!gdb_python_initialized)
1486 gdbpy_enter_varobj enter_py (var);
1488 mainmod = PyImport_AddModule ("__main__");
1489 gdbpy_ref globals (PyModule_GetDict (mainmod));
1490 Py_INCREF (globals.get ());
1492 gdbpy_ref constructor (PyRun_String (visualizer, Py_eval_input,
1493 globals.get (), globals.get ()));
1495 if (constructor == NULL)
1497 gdbpy_print_stack ();
1498 error (_("Could not evaluate visualizer expression: %s"), visualizer);
1501 construct_visualizer (var, constructor.get ());
1503 /* If there are any children now, wipe them. */
1504 varobj_delete (var, 1 /* children only */);
1505 var->num_children = -1;
1507 error (_("Python support required"));
1511 /* If NEW_VALUE is the new value of the given varobj (var), return
1512 non-zero if var has mutated. In other words, if the type of
1513 the new value is different from the type of the varobj's old
1516 NEW_VALUE may be NULL, if the varobj is now out of scope. */
1519 varobj_value_has_mutated (const struct varobj *var, struct value *new_value,
1520 struct type *new_type)
1522 /* If we haven't previously computed the number of children in var,
1523 it does not matter from the front-end's perspective whether
1524 the type has mutated or not. For all intents and purposes,
1525 it has not mutated. */
1526 if (var->num_children < 0)
1529 if (var->root->lang_ops->value_has_mutated)
1531 /* The varobj module, when installing new values, explicitly strips
1532 references, saying that we're not interested in those addresses.
1533 But detection of mutation happens before installing the new
1534 value, so our value may be a reference that we need to strip
1535 in order to remain consistent. */
1536 if (new_value != NULL)
1537 new_value = coerce_ref (new_value);
1538 return var->root->lang_ops->value_has_mutated (var, new_value, new_type);
1544 /* Update the values for a variable and its children. This is a
1545 two-pronged attack. First, re-parse the value for the root's
1546 expression to see if it's changed. Then go all the way
1547 through its children, reconstructing them and noting if they've
1550 The EXPLICIT parameter specifies if this call is result
1551 of MI request to update this specific variable, or
1552 result of implicit -var-update *. For implicit request, we don't
1553 update frozen variables.
1555 NOTE: This function may delete the caller's varobj. If it
1556 returns TYPE_CHANGED, then it has done this and VARP will be modified
1557 to point to the new varobj. */
1559 VEC(varobj_update_result) *
1560 varobj_update (struct varobj **varp, int is_explicit)
1562 int type_changed = 0;
1564 struct value *newobj;
1565 VEC (varobj_update_result) *stack = NULL;
1566 VEC (varobj_update_result) *result = NULL;
1568 /* Frozen means frozen -- we don't check for any change in
1569 this varobj, including its going out of scope, or
1570 changing type. One use case for frozen varobjs is
1571 retaining previously evaluated expressions, and we don't
1572 want them to be reevaluated at all. */
1573 if (!is_explicit && (*varp)->frozen)
1576 if (!(*varp)->root->is_valid)
1578 varobj_update_result r = {0};
1581 r.status = VAROBJ_INVALID;
1582 VEC_safe_push (varobj_update_result, result, &r);
1586 if ((*varp)->root->rootvar == *varp)
1588 varobj_update_result r = {0};
1591 r.status = VAROBJ_IN_SCOPE;
1593 /* Update the root variable. value_of_root can return NULL
1594 if the variable is no longer around, i.e. we stepped out of
1595 the frame in which a local existed. We are letting the
1596 value_of_root variable dispose of the varobj if the type
1598 newobj = value_of_root (varp, &type_changed);
1599 if (update_type_if_necessary(*varp, newobj))
1602 r.type_changed = type_changed;
1603 if (install_new_value ((*varp), newobj, type_changed))
1607 r.status = VAROBJ_NOT_IN_SCOPE;
1608 r.value_installed = 1;
1610 if (r.status == VAROBJ_NOT_IN_SCOPE)
1612 if (r.type_changed || r.changed)
1613 VEC_safe_push (varobj_update_result, result, &r);
1617 VEC_safe_push (varobj_update_result, stack, &r);
1621 varobj_update_result r = {0};
1624 VEC_safe_push (varobj_update_result, stack, &r);
1627 /* Walk through the children, reconstructing them all. */
1628 while (!VEC_empty (varobj_update_result, stack))
1630 varobj_update_result r = *(VEC_last (varobj_update_result, stack));
1631 struct varobj *v = r.varobj;
1633 VEC_pop (varobj_update_result, stack);
1635 /* Update this variable, unless it's a root, which is already
1637 if (!r.value_installed)
1639 struct type *new_type;
1641 newobj = value_of_child (v->parent, v->index);
1642 if (update_type_if_necessary(v, newobj))
1645 new_type = value_type (newobj);
1647 new_type = v->root->lang_ops->type_of_child (v->parent, v->index);
1649 if (varobj_value_has_mutated (v, newobj, new_type))
1651 /* The children are no longer valid; delete them now.
1652 Report the fact that its type changed as well. */
1653 varobj_delete (v, 1 /* only_children */);
1654 v->num_children = -1;
1661 if (install_new_value (v, newobj, r.type_changed))
1668 /* We probably should not get children of a dynamic varobj, but
1669 for which -var-list-children was never invoked. */
1670 if (varobj_is_dynamic_p (v))
1672 VEC (varobj_p) *changed = 0, *type_changed = 0, *unchanged = 0;
1673 VEC (varobj_p) *newobj = 0;
1674 int i, children_changed = 0;
1679 if (!v->dynamic->children_requested)
1683 /* If we initially did not have potential children, but
1684 now we do, consider the varobj as changed.
1685 Otherwise, if children were never requested, consider
1686 it as unchanged -- presumably, such varobj is not yet
1687 expanded in the UI, so we need not bother getting
1689 if (!varobj_has_more (v, 0))
1691 update_dynamic_varobj_children (v, NULL, NULL, NULL, NULL,
1693 if (varobj_has_more (v, 0))
1698 VEC_safe_push (varobj_update_result, result, &r);
1703 /* If update_dynamic_varobj_children returns 0, then we have
1704 a non-conforming pretty-printer, so we skip it. */
1705 if (update_dynamic_varobj_children (v, &changed, &type_changed, &newobj,
1706 &unchanged, &children_changed, 1,
1709 if (children_changed || newobj)
1711 r.children_changed = 1;
1714 /* Push in reverse order so that the first child is
1715 popped from the work stack first, and so will be
1716 added to result first. This does not affect
1717 correctness, just "nicer". */
1718 for (i = VEC_length (varobj_p, type_changed) - 1; i >= 0; --i)
1720 varobj_p tmp = VEC_index (varobj_p, type_changed, i);
1721 varobj_update_result r = {0};
1723 /* Type may change only if value was changed. */
1727 r.value_installed = 1;
1728 VEC_safe_push (varobj_update_result, stack, &r);
1730 for (i = VEC_length (varobj_p, changed) - 1; i >= 0; --i)
1732 varobj_p tmp = VEC_index (varobj_p, changed, i);
1733 varobj_update_result r = {0};
1737 r.value_installed = 1;
1738 VEC_safe_push (varobj_update_result, stack, &r);
1740 for (i = VEC_length (varobj_p, unchanged) - 1; i >= 0; --i)
1742 varobj_p tmp = VEC_index (varobj_p, unchanged, i);
1746 varobj_update_result r = {0};
1749 r.value_installed = 1;
1750 VEC_safe_push (varobj_update_result, stack, &r);
1753 if (r.changed || r.children_changed)
1754 VEC_safe_push (varobj_update_result, result, &r);
1756 /* Free CHANGED, TYPE_CHANGED and UNCHANGED, but not NEW,
1757 because NEW has been put into the result vector. */
1758 VEC_free (varobj_p, changed);
1759 VEC_free (varobj_p, type_changed);
1760 VEC_free (varobj_p, unchanged);
1766 /* Push any children. Use reverse order so that the first
1767 child is popped from the work stack first, and so
1768 will be added to result first. This does not
1769 affect correctness, just "nicer". */
1770 for (i = VEC_length (varobj_p, v->children)-1; i >= 0; --i)
1772 varobj_p c = VEC_index (varobj_p, v->children, i);
1774 /* Child may be NULL if explicitly deleted by -var-delete. */
1775 if (c != NULL && !c->frozen)
1777 varobj_update_result r = {0};
1780 VEC_safe_push (varobj_update_result, stack, &r);
1784 if (r.changed || r.type_changed)
1785 VEC_safe_push (varobj_update_result, result, &r);
1788 VEC_free (varobj_update_result, stack);
1794 /* Helper functions */
1797 * Variable object construction/destruction
1801 delete_variable (struct varobj *var, int only_children_p)
1805 delete_variable_1 (&delcount, var, only_children_p,
1806 1 /* remove_from_parent_p */ );
1811 /* Delete the variable object VAR and its children. */
1812 /* IMPORTANT NOTE: If we delete a variable which is a child
1813 and the parent is not removed we dump core. It must be always
1814 initially called with remove_from_parent_p set. */
1816 delete_variable_1 (int *delcountp, struct varobj *var, int only_children_p,
1817 int remove_from_parent_p)
1821 /* Delete any children of this variable, too. */
1822 for (i = 0; i < VEC_length (varobj_p, var->children); ++i)
1824 varobj_p child = VEC_index (varobj_p, var->children, i);
1828 if (!remove_from_parent_p)
1829 child->parent = NULL;
1830 delete_variable_1 (delcountp, child, 0, only_children_p);
1832 VEC_free (varobj_p, var->children);
1834 /* if we were called to delete only the children we are done here. */
1835 if (only_children_p)
1838 /* Otherwise, add it to the list of deleted ones and proceed to do so. */
1839 /* If the name is empty, this is a temporary variable, that has not
1840 yet been installed, don't report it, it belongs to the caller... */
1841 if (!var->obj_name.empty ())
1843 *delcountp = *delcountp + 1;
1846 /* If this variable has a parent, remove it from its parent's list. */
1847 /* OPTIMIZATION: if the parent of this variable is also being deleted,
1848 (as indicated by remove_from_parent_p) we don't bother doing an
1849 expensive list search to find the element to remove when we are
1850 discarding the list afterwards. */
1851 if ((remove_from_parent_p) && (var->parent != NULL))
1853 VEC_replace (varobj_p, var->parent->children, var->index, NULL);
1856 if (!var->obj_name.empty ())
1857 uninstall_variable (var);
1859 /* Free memory associated with this variable. */
1860 free_variable (var);
1863 /* Install the given variable VAR with the object name VAR->OBJ_NAME. */
1865 install_variable (struct varobj *var)
1868 struct vlist *newvl;
1870 unsigned int index = 0;
1873 for (chp = var->obj_name.c_str (); *chp; chp++)
1875 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1878 cv = *(varobj_table + index);
1879 while (cv != NULL && cv->var->obj_name != var->obj_name)
1883 error (_("Duplicate variable object name"));
1885 /* Add varobj to hash table. */
1886 newvl = XNEW (struct vlist);
1887 newvl->next = *(varobj_table + index);
1889 *(varobj_table + index) = newvl;
1891 /* If root, add varobj to root list. */
1892 if (is_root_p (var))
1894 /* Add to list of root variables. */
1895 if (rootlist == NULL)
1896 var->root->next = NULL;
1898 var->root->next = rootlist;
1899 rootlist = var->root;
1905 /* Unistall the object VAR. */
1907 uninstall_variable (struct varobj *var)
1911 struct varobj_root *cr;
1912 struct varobj_root *prer;
1914 unsigned int index = 0;
1917 /* Remove varobj from hash table. */
1918 for (chp = var->obj_name.c_str (); *chp; chp++)
1920 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1923 cv = *(varobj_table + index);
1925 while (cv != NULL && cv->var->obj_name != var->obj_name)
1932 fprintf_unfiltered (gdb_stdlog, "Deleting %s\n", var->obj_name.c_str ());
1937 ("Assertion failed: Could not find variable object \"%s\" to delete",
1938 var->obj_name.c_str ());
1943 *(varobj_table + index) = cv->next;
1945 prev->next = cv->next;
1949 /* If root, remove varobj from root list. */
1950 if (is_root_p (var))
1952 /* Remove from list of root variables. */
1953 if (rootlist == var->root)
1954 rootlist = var->root->next;
1959 while ((cr != NULL) && (cr->rootvar != var))
1966 warning (_("Assertion failed: Could not find "
1967 "varobj \"%s\" in root list"),
1968 var->obj_name.c_str ());
1974 prer->next = cr->next;
1980 /* Create and install a child of the parent of the given name.
1982 The created VAROBJ takes ownership of the allocated NAME. */
1984 static struct varobj *
1985 create_child (struct varobj *parent, int index, std::string &name)
1987 struct varobj_item item;
1989 std::swap (item.name, name);
1990 item.value = value_of_child (parent, index);
1992 return create_child_with_value (parent, index, &item);
1995 static struct varobj *
1996 create_child_with_value (struct varobj *parent, int index,
1997 struct varobj_item *item)
1999 struct varobj *child;
2001 child = new_variable ();
2003 /* NAME is allocated by caller. */
2004 std::swap (child->name, item->name);
2005 child->index = index;
2006 child->parent = parent;
2007 child->root = parent->root;
2009 if (varobj_is_anonymous_child (child))
2010 child->obj_name = string_printf ("%s.%d_anonymous",
2011 parent->obj_name.c_str (), index);
2013 child->obj_name = string_printf ("%s.%s",
2014 parent->obj_name.c_str (),
2015 child->name.c_str ());
2017 install_variable (child);
2019 /* Compute the type of the child. Must do this before
2020 calling install_new_value. */
2021 if (item->value != NULL)
2022 /* If the child had no evaluation errors, var->value
2023 will be non-NULL and contain a valid type. */
2024 child->type = value_actual_type (item->value, 0, NULL);
2026 /* Otherwise, we must compute the type. */
2027 child->type = (*child->root->lang_ops->type_of_child) (child->parent,
2029 install_new_value (child, item->value, 1);
2036 * Miscellaneous utility functions.
2039 /* Allocate memory and initialize a new variable. */
2040 static struct varobj *
2045 var = new varobj ();
2049 var->num_children = -1;
2051 var->children = NULL;
2052 var->format = FORMAT_NATURAL;
2056 var->not_fetched = 0;
2057 var->dynamic = XNEW (struct varobj_dynamic);
2058 var->dynamic->children_requested = 0;
2061 var->dynamic->constructor = 0;
2062 var->dynamic->pretty_printer = 0;
2063 var->dynamic->child_iter = 0;
2064 var->dynamic->saved_item = 0;
2069 /* Allocate memory and initialize a new root variable. */
2070 static struct varobj *
2071 new_root_variable (void)
2073 struct varobj *var = new_variable ();
2075 var->root = new varobj_root ();
2076 var->root->lang_ops = NULL;
2077 var->root->exp = NULL;
2078 var->root->valid_block = NULL;
2079 var->root->frame = null_frame_id;
2080 var->root->floating = 0;
2081 var->root->rootvar = NULL;
2082 var->root->is_valid = 1;
2087 /* Free any allocated memory associated with VAR. */
2089 free_variable (struct varobj *var)
2092 if (var->dynamic->pretty_printer != NULL)
2094 gdbpy_enter_varobj enter_py (var);
2096 Py_XDECREF (var->dynamic->constructor);
2097 Py_XDECREF (var->dynamic->pretty_printer);
2101 varobj_iter_delete (var->dynamic->child_iter);
2102 varobj_clear_saved_item (var->dynamic);
2103 value_free (var->value);
2105 if (is_root_p (var))
2108 xfree (var->dynamic);
2113 do_free_variable_cleanup (void *var)
2115 free_variable ((struct varobj *) var);
2118 static struct cleanup *
2119 make_cleanup_free_variable (struct varobj *var)
2121 return make_cleanup (do_free_variable_cleanup, var);
2124 /* Return the type of the value that's stored in VAR,
2125 or that would have being stored there if the
2126 value were accessible.
2128 This differs from VAR->type in that VAR->type is always
2129 the true type of the expession in the source language.
2130 The return value of this function is the type we're
2131 actually storing in varobj, and using for displaying
2132 the values and for comparing previous and new values.
2134 For example, top-level references are always stripped. */
2136 varobj_get_value_type (const struct varobj *var)
2141 type = value_type (var->value);
2145 type = check_typedef (type);
2147 if (TYPE_CODE (type) == TYPE_CODE_REF)
2148 type = get_target_type (type);
2150 type = check_typedef (type);
2155 /* What is the default display for this variable? We assume that
2156 everything is "natural". Any exceptions? */
2157 static enum varobj_display_formats
2158 variable_default_display (struct varobj *var)
2160 return FORMAT_NATURAL;
2164 * Language-dependencies
2167 /* Common entry points */
2169 /* Return the number of children for a given variable.
2170 The result of this function is defined by the language
2171 implementation. The number of children returned by this function
2172 is the number of children that the user will see in the variable
2175 number_of_children (const struct varobj *var)
2177 return (*var->root->lang_ops->number_of_children) (var);
2180 /* What is the expression for the root varobj VAR? */
2183 name_of_variable (const struct varobj *var)
2185 return (*var->root->lang_ops->name_of_variable) (var);
2188 /* What is the name of the INDEX'th child of VAR? */
2191 name_of_child (struct varobj *var, int index)
2193 return (*var->root->lang_ops->name_of_child) (var, index);
2196 /* If frame associated with VAR can be found, switch
2197 to it and return 1. Otherwise, return 0. */
2200 check_scope (const struct varobj *var)
2202 struct frame_info *fi;
2205 fi = frame_find_by_id (var->root->frame);
2210 CORE_ADDR pc = get_frame_pc (fi);
2212 if (pc < BLOCK_START (var->root->valid_block) ||
2213 pc >= BLOCK_END (var->root->valid_block))
2221 /* Helper function to value_of_root. */
2223 static struct value *
2224 value_of_root_1 (struct varobj **var_handle)
2226 struct value *new_val = NULL;
2227 struct varobj *var = *var_handle;
2228 int within_scope = 0;
2229 struct cleanup *back_to;
2231 /* Only root variables can be updated... */
2232 if (!is_root_p (var))
2233 /* Not a root var. */
2236 back_to = make_cleanup_restore_current_thread ();
2238 /* Determine whether the variable is still around. */
2239 if (var->root->valid_block == NULL || var->root->floating)
2241 else if (var->root->thread_id == 0)
2243 /* The program was single-threaded when the variable object was
2244 created. Technically, it's possible that the program became
2245 multi-threaded since then, but we don't support such
2247 within_scope = check_scope (var);
2251 ptid_t ptid = global_thread_id_to_ptid (var->root->thread_id);
2253 if (!ptid_equal (minus_one_ptid, ptid))
2255 switch_to_thread (ptid);
2256 within_scope = check_scope (var);
2263 /* We need to catch errors here, because if evaluate
2264 expression fails we want to just return NULL. */
2267 new_val = evaluate_expression (var->root->exp.get ());
2269 CATCH (except, RETURN_MASK_ERROR)
2275 do_cleanups (back_to);
2280 /* What is the ``struct value *'' of the root variable VAR?
2281 For floating variable object, evaluation can get us a value
2282 of different type from what is stored in varobj already. In
2284 - *type_changed will be set to 1
2285 - old varobj will be freed, and new one will be
2286 created, with the same name.
2287 - *var_handle will be set to the new varobj
2288 Otherwise, *type_changed will be set to 0. */
2289 static struct value *
2290 value_of_root (struct varobj **var_handle, int *type_changed)
2294 if (var_handle == NULL)
2299 /* This should really be an exception, since this should
2300 only get called with a root variable. */
2302 if (!is_root_p (var))
2305 if (var->root->floating)
2307 struct varobj *tmp_var;
2309 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2310 USE_SELECTED_FRAME);
2311 if (tmp_var == NULL)
2315 std::string old_type = varobj_get_type (var);
2316 std::string new_type = varobj_get_type (tmp_var);
2317 if (old_type == new_type)
2319 /* The expression presently stored inside var->root->exp
2320 remembers the locations of local variables relatively to
2321 the frame where the expression was created (in DWARF location
2322 button, for example). Naturally, those locations are not
2323 correct in other frames, so update the expression. */
2325 std::swap (var->root->exp, tmp_var->root->exp);
2327 varobj_delete (tmp_var, 0);
2332 tmp_var->obj_name = var->obj_name;
2333 tmp_var->from = var->from;
2334 tmp_var->to = var->to;
2335 varobj_delete (var, 0);
2337 install_variable (tmp_var);
2338 *var_handle = tmp_var;
2349 struct value *value;
2351 value = value_of_root_1 (var_handle);
2352 if (var->value == NULL || value == NULL)
2354 /* For root varobj-s, a NULL value indicates a scoping issue.
2355 So, nothing to do in terms of checking for mutations. */
2357 else if (varobj_value_has_mutated (var, value, value_type (value)))
2359 /* The type has mutated, so the children are no longer valid.
2360 Just delete them, and tell our caller that the type has
2362 varobj_delete (var, 1 /* only_children */);
2363 var->num_children = -1;
2372 /* What is the ``struct value *'' for the INDEX'th child of PARENT? */
2373 static struct value *
2374 value_of_child (const struct varobj *parent, int index)
2376 struct value *value;
2378 value = (*parent->root->lang_ops->value_of_child) (parent, index);
2383 /* GDB already has a command called "value_of_variable". Sigh. */
2385 my_value_of_variable (struct varobj *var, enum varobj_display_formats format)
2387 if (var->root->is_valid)
2389 if (var->dynamic->pretty_printer != NULL)
2390 return varobj_value_get_print_value (var->value, var->format, var);
2391 return (*var->root->lang_ops->value_of_variable) (var, format);
2394 return std::string ();
2398 varobj_formatted_print_options (struct value_print_options *opts,
2399 enum varobj_display_formats format)
2401 get_formatted_print_options (opts, format_code[(int) format]);
2402 opts->deref_ref = 0;
2407 varobj_value_get_print_value (struct value *value,
2408 enum varobj_display_formats format,
2409 const struct varobj *var)
2411 struct ui_file *stb;
2412 struct cleanup *old_chain;
2413 struct value_print_options opts;
2414 struct type *type = NULL;
2416 gdb::unique_xmalloc_ptr<char> encoding;
2417 /* Initialize it just to avoid a GCC false warning. */
2418 CORE_ADDR str_addr = 0;
2419 int string_print = 0;
2422 return std::string ();
2424 stb = mem_fileopen ();
2425 old_chain = make_cleanup_ui_file_delete (stb);
2427 std::string thevalue;
2430 if (gdb_python_initialized)
2432 PyObject *value_formatter = var->dynamic->pretty_printer;
2434 varobj_ensure_python_env (var);
2436 if (value_formatter)
2438 /* First check to see if we have any children at all. If so,
2439 we simply return {...}. */
2440 if (dynamic_varobj_has_child_method (var))
2442 do_cleanups (old_chain);
2443 return xstrdup ("{...}");
2446 if (PyObject_HasAttr (value_formatter, gdbpy_to_string_cst))
2448 struct value *replacement;
2449 PyObject *output = NULL;
2451 output = apply_varobj_pretty_printer (value_formatter,
2455 /* If we have string like output ... */
2458 make_cleanup_py_decref (output);
2460 /* If this is a lazy string, extract it. For lazy
2461 strings we always print as a string, so set
2463 if (gdbpy_is_lazy_string (output))
2465 gdbpy_extract_lazy_string (output, &str_addr, &type,
2471 /* If it is a regular (non-lazy) string, extract
2472 it and copy the contents into THEVALUE. If the
2473 hint says to print it as a string, set
2474 string_print. Otherwise just return the extracted
2475 string as a value. */
2477 gdb::unique_xmalloc_ptr<char> s
2478 = python_string_to_target_string (output);
2482 struct gdbarch *gdbarch;
2484 gdb::unique_xmalloc_ptr<char> hint
2485 = gdbpy_get_display_hint (value_formatter);
2488 if (!strcmp (hint.get (), "string"))
2492 thevalue = std::string (s.get ());
2493 len = thevalue.size ();
2494 gdbarch = get_type_arch (value_type (value));
2495 type = builtin_type (gdbarch)->builtin_char;
2499 do_cleanups (old_chain);
2504 gdbpy_print_stack ();
2507 /* If the printer returned a replacement value, set VALUE
2508 to REPLACEMENT. If there is not a replacement value,
2509 just use the value passed to this function. */
2511 value = replacement;
2517 varobj_formatted_print_options (&opts, format);
2519 /* If the THEVALUE has contents, it is a regular string. */
2520 if (!thevalue.empty ())
2521 LA_PRINT_STRING (stb, type, (gdb_byte *) thevalue.c_str (),
2522 len, encoding.get (), 0, &opts);
2523 else if (string_print)
2524 /* Otherwise, if string_print is set, and it is not a regular
2525 string, it is a lazy string. */
2526 val_print_string (type, encoding.get (), str_addr, len, stb, &opts);
2528 /* All other cases. */
2529 common_val_print (value, stb, 0, &opts, current_language);
2531 thevalue = ui_file_as_string (stb);
2533 do_cleanups (old_chain);
2538 varobj_editable_p (const struct varobj *var)
2542 if (!(var->root->is_valid && var->value && VALUE_LVAL (var->value)))
2545 type = varobj_get_value_type (var);
2547 switch (TYPE_CODE (type))
2549 case TYPE_CODE_STRUCT:
2550 case TYPE_CODE_UNION:
2551 case TYPE_CODE_ARRAY:
2552 case TYPE_CODE_FUNC:
2553 case TYPE_CODE_METHOD:
2563 /* Call VAR's value_is_changeable_p language-specific callback. */
2566 varobj_value_is_changeable_p (const struct varobj *var)
2568 return var->root->lang_ops->value_is_changeable_p (var);
2571 /* Return 1 if that varobj is floating, that is is always evaluated in the
2572 selected frame, and not bound to thread/frame. Such variable objects
2573 are created using '@' as frame specifier to -var-create. */
2575 varobj_floating_p (const struct varobj *var)
2577 return var->root->floating;
2580 /* Implement the "value_is_changeable_p" varobj callback for most
2584 varobj_default_value_is_changeable_p (const struct varobj *var)
2589 if (CPLUS_FAKE_CHILD (var))
2592 type = varobj_get_value_type (var);
2594 switch (TYPE_CODE (type))
2596 case TYPE_CODE_STRUCT:
2597 case TYPE_CODE_UNION:
2598 case TYPE_CODE_ARRAY:
2609 /* Iterate all the existing _root_ VAROBJs and call the FUNC callback for them
2610 with an arbitrary caller supplied DATA pointer. */
2613 all_root_varobjs (void (*func) (struct varobj *var, void *data), void *data)
2615 struct varobj_root *var_root, *var_root_next;
2617 /* Iterate "safely" - handle if the callee deletes its passed VAROBJ. */
2619 for (var_root = rootlist; var_root != NULL; var_root = var_root_next)
2621 var_root_next = var_root->next;
2623 (*func) (var_root->rootvar, data);
2627 /* Invalidate varobj VAR if it is tied to locals and re-create it if it is
2628 defined on globals. It is a helper for varobj_invalidate.
2630 This function is called after changing the symbol file, in this case the
2631 pointers to "struct type" stored by the varobj are no longer valid. All
2632 varobj must be either re-evaluated, or marked as invalid here. */
2635 varobj_invalidate_iter (struct varobj *var, void *unused)
2637 /* global and floating var must be re-evaluated. */
2638 if (var->root->floating || var->root->valid_block == NULL)
2640 struct varobj *tmp_var;
2642 /* Try to create a varobj with same expression. If we succeed
2643 replace the old varobj, otherwise invalidate it. */
2644 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2646 if (tmp_var != NULL)
2648 tmp_var->obj_name = var->obj_name;
2649 varobj_delete (var, 0);
2650 install_variable (tmp_var);
2653 var->root->is_valid = 0;
2655 else /* locals must be invalidated. */
2656 var->root->is_valid = 0;
2659 /* Invalidate the varobjs that are tied to locals and re-create the ones that
2660 are defined on globals.
2661 Invalidated varobjs will be always printed in_scope="invalid". */
2664 varobj_invalidate (void)
2666 all_root_varobjs (varobj_invalidate_iter, NULL);
2669 extern void _initialize_varobj (void);
2671 _initialize_varobj (void)
2673 varobj_table = XCNEWVEC (struct vlist *, VAROBJ_TABLE_SIZE);
2675 add_setshow_zuinteger_cmd ("varobj", class_maintenance,
2677 _("Set varobj debugging."),
2678 _("Show varobj debugging."),
2679 _("When non-zero, varobj debugging is enabled."),
2680 NULL, show_varobjdebug,
2681 &setdebuglist, &showdebuglist);