1 /* Implementation of the GDB variable objects API.
3 Copyright (C) 1999-2018 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"
33 #include "parser-defs.h"
36 #include "python/python.h"
37 #include "python/python-internal.h"
38 #include "python/py-ref.h"
43 /* Non-zero if we want to see trace of varobj level stuff. */
45 unsigned int varobjdebug = 0;
47 show_varobjdebug (struct ui_file *file, int from_tty,
48 struct cmd_list_element *c, const char *value)
50 fprintf_filtered (file, _("Varobj debugging is %s.\n"), value);
53 /* String representations of gdb's format codes. */
54 const char *varobj_format_string[] =
55 { "natural", "binary", "decimal", "hexadecimal", "octal", "zero-hexadecimal" };
57 /* True if we want to allow Python-based pretty-printing. */
58 static bool pretty_printing = false;
61 varobj_enable_pretty_printing (void)
63 pretty_printing = true;
68 /* 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 = NULL;
78 /* The frame for this expression. This field is set iff valid_block is
80 struct frame_id frame = null_frame_id;
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 true, 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. */
92 bool floating = false;
94 /* Flag that indicates validity: set to false 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 = NULL;
102 /* The varobj for this root node. */
103 struct varobj *rootvar = NULL;
105 /* Next root variable */
106 struct varobj_root *next = NULL;
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 bool children_requested = false;
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 = NULL;
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 = NULL;
128 /* The iterator returned by the printer's 'children' method, or NULL
130 struct varobj_iter *child_iter = NULL;
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 = NULL;
140 /* A list of varobjs */
148 /* Private function prototypes */
150 /* Helper functions for the above subcommands. */
152 static int delete_variable (struct varobj *, bool);
154 static void delete_variable_1 (int *, struct varobj *, bool, bool);
156 static bool 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 enum varobj_display_formats variable_default_display (struct varobj *);
170 static bool update_type_if_necessary (struct varobj *var,
171 struct value *new_value);
173 static bool install_new_value (struct varobj *var, struct value *value,
176 /* Language-specific routines. */
178 static int number_of_children (const struct varobj *);
180 static std::string name_of_variable (const struct varobj *);
182 static std::string name_of_child (struct varobj *, int);
184 static struct value *value_of_root (struct varobj **var_handle, bool *);
186 static struct value *value_of_child (const struct varobj *parent, int index);
188 static std::string my_value_of_variable (struct varobj *var,
189 enum varobj_display_formats format);
191 static bool is_root_p (const struct varobj *var);
193 static struct varobj *varobj_add_child (struct varobj *var,
194 struct varobj_item *item);
198 /* Mappings of varobj_display_formats enums to gdb's format codes. */
199 static int format_code[] = { 0, 't', 'd', 'x', 'o', 'z' };
201 /* Header of the list of root variable objects. */
202 static struct varobj_root *rootlist;
204 /* Prime number indicating the number of buckets in the hash table. */
205 /* A prime large enough to avoid too many collisions. */
206 #define VAROBJ_TABLE_SIZE 227
208 /* Pointer to the varobj hash table (built at run time). */
209 static struct vlist **varobj_table;
213 /* API Implementation */
215 is_root_p (const struct varobj *var)
217 return (var->root->rootvar == var);
222 /* See python-internal.h. */
223 gdbpy_enter_varobj::gdbpy_enter_varobj (const struct varobj *var)
224 : gdbpy_enter (var->root->exp->gdbarch, var->root->exp->language_defn)
230 /* Return the full FRAME which corresponds to the given CORE_ADDR
231 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
233 static struct frame_info *
234 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr)
236 struct frame_info *frame = NULL;
238 if (frame_addr == (CORE_ADDR) 0)
241 for (frame = get_current_frame ();
243 frame = get_prev_frame (frame))
245 /* The CORE_ADDR we get as argument was parsed from a string GDB
246 output as $fp. This output got truncated to gdbarch_addr_bit.
247 Truncate the frame base address in the same manner before
248 comparing it against our argument. */
249 CORE_ADDR frame_base = get_frame_base_address (frame);
250 int addr_bit = gdbarch_addr_bit (get_frame_arch (frame));
252 if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
253 frame_base &= ((CORE_ADDR) 1 << addr_bit) - 1;
255 if (frame_base == frame_addr)
262 /* Creates a varobj (not its children). */
265 varobj_create (const char *objname,
266 const char *expression, CORE_ADDR frame, enum varobj_type type)
268 /* Fill out a varobj structure for the (root) variable being constructed. */
269 std::unique_ptr<varobj> var (new varobj (new varobj_root));
271 if (expression != NULL)
273 struct frame_info *fi;
274 struct frame_id old_id = null_frame_id;
275 const struct block *block;
277 struct value *value = NULL;
280 /* Parse and evaluate the expression, filling in as much of the
281 variable's data as possible. */
283 if (has_stack_frames ())
285 /* Allow creator to specify context of variable. */
286 if ((type == USE_CURRENT_FRAME) || (type == USE_SELECTED_FRAME))
287 fi = get_selected_frame (NULL);
289 /* FIXME: cagney/2002-11-23: This code should be doing a
290 lookup using the frame ID and not just the frame's
291 ``address''. This, of course, means an interface
292 change. However, with out that interface change ISAs,
293 such as the ia64 with its two stacks, won't work.
294 Similar goes for the case where there is a frameless
296 fi = find_frame_addr_in_frame_chain (frame);
301 if (type == USE_SELECTED_FRAME)
302 var->root->floating = true;
308 block = get_frame_block (fi, 0);
309 pc = get_frame_pc (fi);
313 innermost_block.reset (INNERMOST_BLOCK_FOR_SYMBOLS
314 | INNERMOST_BLOCK_FOR_REGISTERS);
315 /* Wrap the call to parse expression, so we can
316 return a sensible error. */
319 var->root->exp = parse_exp_1 (&p, pc, block, 0);
322 CATCH (except, RETURN_MASK_ERROR)
328 /* Don't allow variables to be created for types. */
329 if (var->root->exp->elts[0].opcode == OP_TYPE
330 || var->root->exp->elts[0].opcode == OP_TYPEOF
331 || var->root->exp->elts[0].opcode == OP_DECLTYPE)
333 fprintf_unfiltered (gdb_stderr, "Attempt to use a type name"
334 " as an expression.\n");
338 var->format = variable_default_display (var.get ());
339 var->root->valid_block =
340 var->root->floating ? NULL : innermost_block.block ();
341 var->name = expression;
342 /* For a root var, the name and the expr are the same. */
343 var->path_expr = expression;
345 /* When the frame is different from the current frame,
346 we must select the appropriate frame before parsing
347 the expression, otherwise the value will not be current.
348 Since select_frame is so benign, just call it for all cases. */
349 if (var->root->valid_block)
351 /* User could specify explicit FRAME-ADDR which was not found but
352 EXPRESSION is frame specific and we would not be able to evaluate
353 it correctly next time. With VALID_BLOCK set we must also set
354 FRAME and THREAD_ID. */
356 error (_("Failed to find the specified frame"));
358 var->root->frame = get_frame_id (fi);
359 var->root->thread_id = ptid_to_global_thread_id (inferior_ptid);
360 old_id = get_frame_id (get_selected_frame (NULL));
364 /* We definitely need to catch errors here.
365 If evaluate_expression succeeds we got the value we wanted.
366 But if it fails, we still go on with a call to evaluate_type(). */
369 value = evaluate_expression (var->root->exp.get ());
371 CATCH (except, RETURN_MASK_ERROR)
373 /* Error getting the value. Try to at least get the
375 struct value *type_only_value = evaluate_type (var->root->exp.get ());
377 var->type = value_type (type_only_value);
383 int real_type_found = 0;
385 var->type = value_actual_type (value, 0, &real_type_found);
387 value = value_cast (var->type, value);
390 /* Set language info */
391 var->root->lang_ops = var->root->exp->language_defn->la_varobj_ops;
393 install_new_value (var.get (), value, 1 /* Initial assignment */);
395 /* Set ourselves as our root. */
396 var->root->rootvar = var.get ();
398 /* Reset the selected frame. */
399 if (frame_id_p (old_id))
400 select_frame (frame_find_by_id (old_id));
403 /* If the variable object name is null, that means this
404 is a temporary variable, so don't install it. */
406 if ((var != NULL) && (objname != NULL))
408 var->obj_name = objname;
410 /* If a varobj name is duplicated, the install will fail so
412 if (!install_variable (var.get ()))
416 return var.release ();
419 /* Generates an unique name that can be used for a varobj. */
422 varobj_gen_name (void)
426 /* Generate a name for this object. */
428 return string_printf ("var%d", id);
431 /* Given an OBJNAME, returns the pointer to the corresponding varobj. Call
432 error if OBJNAME cannot be found. */
435 varobj_get_handle (const char *objname)
439 unsigned int index = 0;
442 for (chp = objname; *chp; chp++)
444 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
447 cv = *(varobj_table + index);
448 while (cv != NULL && cv->var->obj_name != objname)
452 error (_("Variable object not found"));
457 /* Given the handle, return the name of the object. */
460 varobj_get_objname (const struct varobj *var)
462 return var->obj_name.c_str ();
465 /* Given the handle, return the expression represented by the
469 varobj_get_expression (const struct varobj *var)
471 return name_of_variable (var);
477 varobj_delete (struct varobj *var, bool only_children)
479 return delete_variable (var, only_children);
484 /* Convenience function for varobj_set_visualizer. Instantiate a
485 pretty-printer for a given value. */
487 instantiate_pretty_printer (PyObject *constructor, struct value *value)
489 PyObject *val_obj = NULL;
492 val_obj = value_to_value_object (value);
496 printer = PyObject_CallFunctionObjArgs (constructor, val_obj, NULL);
503 /* Set/Get variable object display format. */
505 enum varobj_display_formats
506 varobj_set_display_format (struct varobj *var,
507 enum varobj_display_formats format)
514 case FORMAT_HEXADECIMAL:
516 case FORMAT_ZHEXADECIMAL:
517 var->format = format;
521 var->format = variable_default_display (var);
524 if (varobj_value_is_changeable_p (var)
525 && var->value && !value_lazy (var->value))
527 var->print_value = varobj_value_get_print_value (var->value,
534 enum varobj_display_formats
535 varobj_get_display_format (const struct varobj *var)
540 gdb::unique_xmalloc_ptr<char>
541 varobj_get_display_hint (const struct varobj *var)
543 gdb::unique_xmalloc_ptr<char> result;
546 if (!gdb_python_initialized)
549 gdbpy_enter_varobj enter_py (var);
551 if (var->dynamic->pretty_printer != NULL)
552 result = gdbpy_get_display_hint (var->dynamic->pretty_printer);
558 /* Return true if the varobj has items after TO, false otherwise. */
561 varobj_has_more (const struct varobj *var, int to)
563 if (var->children.size () > to)
566 return ((to == -1 || var->children.size () == to)
567 && (var->dynamic->saved_item != NULL));
570 /* If the variable object is bound to a specific thread, that
571 is its evaluation can always be done in context of a frame
572 inside that thread, returns GDB id of the thread -- which
573 is always positive. Otherwise, returns -1. */
575 varobj_get_thread_id (const struct varobj *var)
577 if (var->root->valid_block && var->root->thread_id > 0)
578 return var->root->thread_id;
584 varobj_set_frozen (struct varobj *var, bool frozen)
586 /* When a variable is unfrozen, we don't fetch its value.
587 The 'not_fetched' flag remains set, so next -var-update
590 We don't fetch the value, because for structures the client
591 should do -var-update anyway. It would be bad to have different
592 client-size logic for structure and other types. */
593 var->frozen = frozen;
597 varobj_get_frozen (const struct varobj *var)
602 /* A helper function that restricts a range to what is actually
603 available in a VEC. This follows the usual rules for the meaning
604 of FROM and TO -- if either is negative, the entire range is
608 varobj_restrict_range (const std::vector<varobj *> &children,
611 int len = children.size ();
613 if (*from < 0 || *to < 0)
629 /* A helper for update_dynamic_varobj_children that installs a new
630 child when needed. */
633 install_dynamic_child (struct varobj *var,
634 std::vector<varobj *> *changed,
635 std::vector<varobj *> *type_changed,
636 std::vector<varobj *> *newobj,
637 std::vector<varobj *> *unchanged,
640 struct varobj_item *item)
642 if (var->children.size () < index + 1)
644 /* There's no child yet. */
645 struct varobj *child = varobj_add_child (var, item);
649 newobj->push_back (child);
655 varobj *existing = var->children[index];
656 bool type_updated = update_type_if_necessary (existing, item->value);
660 if (type_changed != NULL)
661 type_changed->push_back (existing);
663 if (install_new_value (existing, item->value, 0))
665 if (!type_updated && changed != NULL)
666 changed->push_back (existing);
668 else if (!type_updated && unchanged != NULL)
669 unchanged->push_back (existing);
676 dynamic_varobj_has_child_method (const struct varobj *var)
678 PyObject *printer = var->dynamic->pretty_printer;
680 if (!gdb_python_initialized)
683 gdbpy_enter_varobj enter_py (var);
684 return PyObject_HasAttr (printer, gdbpy_children_cst);
688 /* A factory for creating dynamic varobj's iterators. Returns an
689 iterator object suitable for iterating over VAR's children. */
691 static struct varobj_iter *
692 varobj_get_iterator (struct varobj *var)
695 if (var->dynamic->pretty_printer)
696 return py_varobj_get_iterator (var, var->dynamic->pretty_printer);
699 gdb_assert_not_reached (_("\
700 requested an iterator from a non-dynamic varobj"));
703 /* Release and clear VAR's saved item, if any. */
706 varobj_clear_saved_item (struct varobj_dynamic *var)
708 if (var->saved_item != NULL)
710 value_free (var->saved_item->value);
711 delete var->saved_item;
712 var->saved_item = NULL;
717 update_dynamic_varobj_children (struct varobj *var,
718 std::vector<varobj *> *changed,
719 std::vector<varobj *> *type_changed,
720 std::vector<varobj *> *newobj,
721 std::vector<varobj *> *unchanged,
723 bool update_children,
731 if (update_children || var->dynamic->child_iter == NULL)
733 varobj_iter_delete (var->dynamic->child_iter);
734 var->dynamic->child_iter = varobj_get_iterator (var);
736 varobj_clear_saved_item (var->dynamic);
740 if (var->dynamic->child_iter == NULL)
744 i = var->children.size ();
746 /* We ask for one extra child, so that MI can report whether there
747 are more children. */
748 for (; to < 0 || i < to + 1; ++i)
752 /* See if there was a leftover from last time. */
753 if (var->dynamic->saved_item != NULL)
755 item = var->dynamic->saved_item;
756 var->dynamic->saved_item = NULL;
760 item = varobj_iter_next (var->dynamic->child_iter);
761 /* Release vitem->value so its lifetime is not bound to the
762 execution of a command. */
763 if (item != NULL && item->value != NULL)
764 release_value_or_incref (item->value);
769 /* Iteration is done. Remove iterator from VAR. */
770 varobj_iter_delete (var->dynamic->child_iter);
771 var->dynamic->child_iter = NULL;
774 /* We don't want to push the extra child on any report list. */
775 if (to < 0 || i < to)
777 bool can_mention = from < 0 || i >= from;
779 install_dynamic_child (var, can_mention ? changed : NULL,
780 can_mention ? type_changed : NULL,
781 can_mention ? newobj : NULL,
782 can_mention ? unchanged : NULL,
783 can_mention ? cchanged : NULL, i,
790 var->dynamic->saved_item = item;
792 /* We want to truncate the child list just before this
798 if (i < var->children.size ())
801 for (int j = i; j < var->children.size (); ++j)
802 varobj_delete (var->children[j], 0);
804 var->children.resize (i);
807 /* If there are fewer children than requested, note that the list of
809 if (to >= 0 && var->children.size () < to)
812 var->num_children = var->children.size ();
818 varobj_get_num_children (struct varobj *var)
820 if (var->num_children == -1)
822 if (varobj_is_dynamic_p (var))
826 /* If we have a dynamic varobj, don't report -1 children.
827 So, try to fetch some children first. */
828 update_dynamic_varobj_children (var, NULL, NULL, NULL, NULL, &dummy,
832 var->num_children = number_of_children (var);
835 return var->num_children >= 0 ? var->num_children : 0;
838 /* Creates a list of the immediate children of a variable object;
839 the return code is the number of such children or -1 on error. */
841 const std::vector<varobj *> &
842 varobj_list_children (struct varobj *var, int *from, int *to)
844 var->dynamic->children_requested = true;
846 if (varobj_is_dynamic_p (var))
848 bool children_changed;
850 /* This, in theory, can result in the number of children changing without
851 frontend noticing. But well, calling -var-list-children on the same
852 varobj twice is not something a sane frontend would do. */
853 update_dynamic_varobj_children (var, NULL, NULL, NULL, NULL,
854 &children_changed, false, 0, *to);
855 varobj_restrict_range (var->children, from, to);
856 return var->children;
859 if (var->num_children == -1)
860 var->num_children = number_of_children (var);
862 /* If that failed, give up. */
863 if (var->num_children == -1)
864 return var->children;
866 /* If we're called when the list of children is not yet initialized,
867 allocate enough elements in it. */
868 while (var->children.size () < var->num_children)
869 var->children.push_back (NULL);
871 for (int i = 0; i < var->num_children; i++)
873 if (var->children[i] == NULL)
875 /* Either it's the first call to varobj_list_children for
876 this variable object, and the child was never created,
877 or it was explicitly deleted by the client. */
878 std::string name = name_of_child (var, i);
879 var->children[i] = create_child (var, i, name);
883 varobj_restrict_range (var->children, from, to);
884 return var->children;
887 static struct varobj *
888 varobj_add_child (struct varobj *var, struct varobj_item *item)
890 varobj *v = create_child_with_value (var, var->children.size (), item);
892 var->children.push_back (v);
897 /* Obtain the type of an object Variable as a string similar to the one gdb
898 prints on the console. The caller is responsible for freeing the string.
902 varobj_get_type (struct varobj *var)
904 /* For the "fake" variables, do not return a type. (Its type is
906 Do not return a type for invalid variables as well. */
907 if (CPLUS_FAKE_CHILD (var) || !var->root->is_valid)
908 return std::string ();
910 return type_to_string (var->type);
913 /* Obtain the type of an object variable. */
916 varobj_get_gdb_type (const struct varobj *var)
921 /* Is VAR a path expression parent, i.e., can it be used to construct
922 a valid path expression? */
925 is_path_expr_parent (const struct varobj *var)
927 gdb_assert (var->root->lang_ops->is_path_expr_parent != NULL);
928 return var->root->lang_ops->is_path_expr_parent (var);
931 /* Is VAR a path expression parent, i.e., can it be used to construct
932 a valid path expression? By default we assume any VAR can be a path
936 varobj_default_is_path_expr_parent (const struct varobj *var)
941 /* Return the path expression parent for VAR. */
943 const struct varobj *
944 varobj_get_path_expr_parent (const struct varobj *var)
946 const struct varobj *parent = var;
948 while (!is_root_p (parent) && !is_path_expr_parent (parent))
949 parent = parent->parent;
954 /* Return a pointer to the full rooted expression of varobj VAR.
955 If it has not been computed yet, compute it. */
958 varobj_get_path_expr (const struct varobj *var)
960 if (var->path_expr.empty ())
962 /* For root varobjs, we initialize path_expr
963 when creating varobj, so here it should be
965 struct varobj *mutable_var = (struct varobj *) var;
966 gdb_assert (!is_root_p (var));
968 mutable_var->path_expr = (*var->root->lang_ops->path_expr_of_child) (var);
971 return var->path_expr.c_str ();
974 const struct language_defn *
975 varobj_get_language (const struct varobj *var)
977 return var->root->exp->language_defn;
981 varobj_get_attributes (const struct varobj *var)
985 if (varobj_editable_p (var))
986 /* FIXME: define masks for attributes. */
987 attributes |= 0x00000001; /* Editable */
992 /* Return true if VAR is a dynamic varobj. */
995 varobj_is_dynamic_p (const struct varobj *var)
997 return var->dynamic->pretty_printer != NULL;
1001 varobj_get_formatted_value (struct varobj *var,
1002 enum varobj_display_formats format)
1004 return my_value_of_variable (var, format);
1008 varobj_get_value (struct varobj *var)
1010 return my_value_of_variable (var, var->format);
1013 /* Set the value of an object variable (if it is editable) to the
1014 value of the given expression. */
1015 /* Note: Invokes functions that can call error(). */
1018 varobj_set_value (struct varobj *var, const char *expression)
1020 struct value *val = NULL; /* Initialize to keep gcc happy. */
1021 /* The argument "expression" contains the variable's new value.
1022 We need to first construct a legal expression for this -- ugh! */
1023 /* Does this cover all the bases? */
1024 struct value *value = NULL; /* Initialize to keep gcc happy. */
1025 int saved_input_radix = input_radix;
1026 const char *s = expression;
1028 gdb_assert (varobj_editable_p (var));
1030 input_radix = 10; /* ALWAYS reset to decimal temporarily. */
1031 expression_up exp = parse_exp_1 (&s, 0, 0, 0);
1034 value = evaluate_expression (exp.get ());
1037 CATCH (except, RETURN_MASK_ERROR)
1039 /* We cannot proceed without a valid expression. */
1044 /* All types that are editable must also be changeable. */
1045 gdb_assert (varobj_value_is_changeable_p (var));
1047 /* The value of a changeable variable object must not be lazy. */
1048 gdb_assert (!value_lazy (var->value));
1050 /* Need to coerce the input. We want to check if the
1051 value of the variable object will be different
1052 after assignment, and the first thing value_assign
1053 does is coerce the input.
1054 For example, if we are assigning an array to a pointer variable we
1055 should compare the pointer with the array's address, not with the
1057 value = coerce_array (value);
1059 /* The new value may be lazy. value_assign, or
1060 rather value_contents, will take care of this. */
1063 val = value_assign (var->value, value);
1066 CATCH (except, RETURN_MASK_ERROR)
1072 /* If the value has changed, record it, so that next -var-update can
1073 report this change. If a variable had a value of '1', we've set it
1074 to '333' and then set again to '1', when -var-update will report this
1075 variable as changed -- because the first assignment has set the
1076 'updated' flag. There's no need to optimize that, because return value
1077 of -var-update should be considered an approximation. */
1078 var->updated = install_new_value (var, val, false /* Compare values. */);
1079 input_radix = saved_input_radix;
1085 /* A helper function to install a constructor function and visualizer
1086 in a varobj_dynamic. */
1089 install_visualizer (struct varobj_dynamic *var, PyObject *constructor,
1090 PyObject *visualizer)
1092 Py_XDECREF (var->constructor);
1093 var->constructor = constructor;
1095 Py_XDECREF (var->pretty_printer);
1096 var->pretty_printer = visualizer;
1098 varobj_iter_delete (var->child_iter);
1099 var->child_iter = NULL;
1102 /* Install the default visualizer for VAR. */
1105 install_default_visualizer (struct varobj *var)
1107 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1108 if (CPLUS_FAKE_CHILD (var))
1111 if (pretty_printing)
1113 PyObject *pretty_printer = NULL;
1117 pretty_printer = gdbpy_get_varobj_pretty_printer (var->value);
1118 if (! pretty_printer)
1120 gdbpy_print_stack ();
1121 error (_("Cannot instantiate printer for default visualizer"));
1125 if (pretty_printer == Py_None)
1127 Py_DECREF (pretty_printer);
1128 pretty_printer = NULL;
1131 install_visualizer (var->dynamic, NULL, pretty_printer);
1135 /* Instantiate and install a visualizer for VAR using CONSTRUCTOR to
1136 make a new object. */
1139 construct_visualizer (struct varobj *var, PyObject *constructor)
1141 PyObject *pretty_printer;
1143 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1144 if (CPLUS_FAKE_CHILD (var))
1147 Py_INCREF (constructor);
1148 if (constructor == Py_None)
1149 pretty_printer = NULL;
1152 pretty_printer = instantiate_pretty_printer (constructor, var->value);
1153 if (! pretty_printer)
1155 gdbpy_print_stack ();
1156 Py_DECREF (constructor);
1157 constructor = Py_None;
1158 Py_INCREF (constructor);
1161 if (pretty_printer == Py_None)
1163 Py_DECREF (pretty_printer);
1164 pretty_printer = NULL;
1168 install_visualizer (var->dynamic, constructor, pretty_printer);
1171 #endif /* HAVE_PYTHON */
1173 /* A helper function for install_new_value. This creates and installs
1174 a visualizer for VAR, if appropriate. */
1177 install_new_value_visualizer (struct varobj *var)
1180 /* If the constructor is None, then we want the raw value. If VAR
1181 does not have a value, just skip this. */
1182 if (!gdb_python_initialized)
1185 if (var->dynamic->constructor != Py_None && var->value != NULL)
1187 gdbpy_enter_varobj enter_py (var);
1189 if (var->dynamic->constructor == NULL)
1190 install_default_visualizer (var);
1192 construct_visualizer (var, var->dynamic->constructor);
1199 /* When using RTTI to determine variable type it may be changed in runtime when
1200 the variable value is changed. This function checks whether type of varobj
1201 VAR will change when a new value NEW_VALUE is assigned and if it is so
1202 updates the type of VAR. */
1205 update_type_if_necessary (struct varobj *var, struct value *new_value)
1209 struct value_print_options opts;
1211 get_user_print_options (&opts);
1212 if (opts.objectprint)
1214 struct type *new_type = value_actual_type (new_value, 0, 0);
1215 std::string new_type_str = type_to_string (new_type);
1216 std::string curr_type_str = varobj_get_type (var);
1218 /* Did the type name change? */
1219 if (curr_type_str != new_type_str)
1221 var->type = new_type;
1223 /* This information may be not valid for a new type. */
1224 varobj_delete (var, 1);
1225 var->children.clear ();
1226 var->num_children = -1;
1235 /* Assign a new value to a variable object. If INITIAL is true,
1236 this is the first assignment after the variable object was just
1237 created, or changed type. In that case, just assign the value
1239 Otherwise, assign the new value, and return true if the value is
1240 different from the current one, false otherwise. The comparison is
1241 done on textual representation of value. Therefore, some types
1242 need not be compared. E.g. for structures the reported value is
1243 always "{...}", so no comparison is necessary here. If the old
1244 value was NULL and new one is not, or vice versa, we always return true.
1246 The VALUE parameter should not be released -- the function will
1247 take care of releasing it when needed. */
1249 install_new_value (struct varobj *var, struct value *value, bool initial)
1253 bool changed = false;
1254 bool intentionally_not_fetched = false;
1256 /* We need to know the varobj's type to decide if the value should
1257 be fetched or not. C++ fake children (public/protected/private)
1258 don't have a type. */
1259 gdb_assert (var->type || CPLUS_FAKE_CHILD (var));
1260 changeable = varobj_value_is_changeable_p (var);
1262 /* If the type has custom visualizer, we consider it to be always
1263 changeable. FIXME: need to make sure this behaviour will not
1264 mess up read-sensitive values. */
1265 if (var->dynamic->pretty_printer != NULL)
1268 need_to_fetch = changeable;
1270 /* We are not interested in the address of references, and given
1271 that in C++ a reference is not rebindable, it cannot
1272 meaningfully change. So, get hold of the real value. */
1274 value = coerce_ref (value);
1276 if (var->type && TYPE_CODE (var->type) == TYPE_CODE_UNION)
1277 /* For unions, we need to fetch the value implicitly because
1278 of implementation of union member fetch. When gdb
1279 creates a value for a field and the value of the enclosing
1280 structure is not lazy, it immediately copies the necessary
1281 bytes from the enclosing values. If the enclosing value is
1282 lazy, the call to value_fetch_lazy on the field will read
1283 the data from memory. For unions, that means we'll read the
1284 same memory more than once, which is not desirable. So
1286 need_to_fetch = true;
1288 /* The new value might be lazy. If the type is changeable,
1289 that is we'll be comparing values of this type, fetch the
1290 value now. Otherwise, on the next update the old value
1291 will be lazy, which means we've lost that old value. */
1292 if (need_to_fetch && value && value_lazy (value))
1294 const struct varobj *parent = var->parent;
1295 bool frozen = var->frozen;
1297 for (; !frozen && parent; parent = parent->parent)
1298 frozen |= parent->frozen;
1300 if (frozen && initial)
1302 /* For variables that are frozen, or are children of frozen
1303 variables, we don't do fetch on initial assignment.
1304 For non-initial assignemnt we do the fetch, since it means we're
1305 explicitly asked to compare the new value with the old one. */
1306 intentionally_not_fetched = true;
1313 value_fetch_lazy (value);
1316 CATCH (except, RETURN_MASK_ERROR)
1318 /* Set the value to NULL, so that for the next -var-update,
1319 we don't try to compare the new value with this value,
1320 that we couldn't even read. */
1327 /* Get a reference now, before possibly passing it to any Python
1328 code that might release it. */
1330 value_incref (value);
1332 /* Below, we'll be comparing string rendering of old and new
1333 values. Don't get string rendering if the value is
1334 lazy -- if it is, the code above has decided that the value
1335 should not be fetched. */
1336 std::string print_value;
1337 if (value != NULL && !value_lazy (value)
1338 && var->dynamic->pretty_printer == NULL)
1339 print_value = varobj_value_get_print_value (value, var->format, var);
1341 /* If the type is changeable, compare the old and the new values.
1342 If this is the initial assignment, we don't have any old value
1344 if (!initial && changeable)
1346 /* If the value of the varobj was changed by -var-set-value,
1347 then the value in the varobj and in the target is the same.
1348 However, that value is different from the value that the
1349 varobj had after the previous -var-update. So need to the
1350 varobj as changed. */
1353 else if (var->dynamic->pretty_printer == NULL)
1355 /* Try to compare the values. That requires that both
1356 values are non-lazy. */
1357 if (var->not_fetched && value_lazy (var->value))
1359 /* This is a frozen varobj and the value was never read.
1360 Presumably, UI shows some "never read" indicator.
1361 Now that we've fetched the real value, we need to report
1362 this varobj as changed so that UI can show the real
1366 else if (var->value == NULL && value == NULL)
1369 else if (var->value == NULL || value == NULL)
1375 gdb_assert (!value_lazy (var->value));
1376 gdb_assert (!value_lazy (value));
1378 gdb_assert (!var->print_value.empty () && !print_value.empty ());
1379 if (var->print_value != print_value)
1385 if (!initial && !changeable)
1387 /* For values that are not changeable, we don't compare the values.
1388 However, we want to notice if a value was not NULL and now is NULL,
1389 or vise versa, so that we report when top-level varobjs come in scope
1390 and leave the scope. */
1391 changed = (var->value != NULL) != (value != NULL);
1394 /* We must always keep the new value, since children depend on it. */
1395 if (var->value != NULL && var->value != value)
1396 value_free (var->value);
1398 if (value && value_lazy (value) && intentionally_not_fetched)
1399 var->not_fetched = true;
1401 var->not_fetched = false;
1402 var->updated = false;
1404 install_new_value_visualizer (var);
1406 /* If we installed a pretty-printer, re-compare the printed version
1407 to see if the variable changed. */
1408 if (var->dynamic->pretty_printer != NULL)
1410 print_value = varobj_value_get_print_value (var->value, var->format,
1412 if ((var->print_value.empty () && !print_value.empty ())
1413 || (!var->print_value.empty () && print_value.empty ())
1414 || (!var->print_value.empty () && !print_value.empty ()
1415 && var->print_value != print_value))
1418 var->print_value = print_value;
1420 gdb_assert (!var->value || value_type (var->value));
1425 /* Return the requested range for a varobj. VAR is the varobj. FROM
1426 and TO are out parameters; *FROM and *TO will be set to the
1427 selected sub-range of VAR. If no range was selected using
1428 -var-set-update-range, then both will be -1. */
1430 varobj_get_child_range (const struct varobj *var, int *from, int *to)
1436 /* Set the selected sub-range of children of VAR to start at index
1437 FROM and end at index TO. If either FROM or TO is less than zero,
1438 this is interpreted as a request for all children. */
1440 varobj_set_child_range (struct varobj *var, int from, int to)
1447 varobj_set_visualizer (struct varobj *var, const char *visualizer)
1452 if (!gdb_python_initialized)
1455 gdbpy_enter_varobj enter_py (var);
1457 mainmod = PyImport_AddModule ("__main__");
1458 gdbpy_ref<> globals (PyModule_GetDict (mainmod));
1459 Py_INCREF (globals.get ());
1461 gdbpy_ref<> constructor (PyRun_String (visualizer, Py_eval_input,
1462 globals.get (), globals.get ()));
1464 if (constructor == NULL)
1466 gdbpy_print_stack ();
1467 error (_("Could not evaluate visualizer expression: %s"), visualizer);
1470 construct_visualizer (var, constructor.get ());
1472 /* If there are any children now, wipe them. */
1473 varobj_delete (var, 1 /* children only */);
1474 var->num_children = -1;
1476 error (_("Python support required"));
1480 /* If NEW_VALUE is the new value of the given varobj (var), return
1481 true if var has mutated. In other words, if the type of
1482 the new value is different from the type of the varobj's old
1485 NEW_VALUE may be NULL, if the varobj is now out of scope. */
1488 varobj_value_has_mutated (const struct varobj *var, struct value *new_value,
1489 struct type *new_type)
1491 /* If we haven't previously computed the number of children in var,
1492 it does not matter from the front-end's perspective whether
1493 the type has mutated or not. For all intents and purposes,
1494 it has not mutated. */
1495 if (var->num_children < 0)
1498 if (var->root->lang_ops->value_has_mutated != NULL)
1500 /* The varobj module, when installing new values, explicitly strips
1501 references, saying that we're not interested in those addresses.
1502 But detection of mutation happens before installing the new
1503 value, so our value may be a reference that we need to strip
1504 in order to remain consistent. */
1505 if (new_value != NULL)
1506 new_value = coerce_ref (new_value);
1507 return var->root->lang_ops->value_has_mutated (var, new_value, new_type);
1513 /* Update the values for a variable and its children. This is a
1514 two-pronged attack. First, re-parse the value for the root's
1515 expression to see if it's changed. Then go all the way
1516 through its children, reconstructing them and noting if they've
1519 The IS_EXPLICIT parameter specifies if this call is result
1520 of MI request to update this specific variable, or
1521 result of implicit -var-update *. For implicit request, we don't
1522 update frozen variables.
1524 NOTE: This function may delete the caller's varobj. If it
1525 returns TYPE_CHANGED, then it has done this and VARP will be modified
1526 to point to the new varobj. */
1528 std::vector<varobj_update_result>
1529 varobj_update (struct varobj **varp, bool is_explicit)
1531 bool type_changed = false;
1532 struct value *newobj;
1533 std::vector<varobj_update_result> stack;
1534 std::vector<varobj_update_result> result;
1536 /* Frozen means frozen -- we don't check for any change in
1537 this varobj, including its going out of scope, or
1538 changing type. One use case for frozen varobjs is
1539 retaining previously evaluated expressions, and we don't
1540 want them to be reevaluated at all. */
1541 if (!is_explicit && (*varp)->frozen)
1544 if (!(*varp)->root->is_valid)
1546 result.emplace_back (*varp, VAROBJ_INVALID);
1550 if ((*varp)->root->rootvar == *varp)
1552 varobj_update_result r (*varp);
1554 /* Update the root variable. value_of_root can return NULL
1555 if the variable is no longer around, i.e. we stepped out of
1556 the frame in which a local existed. We are letting the
1557 value_of_root variable dispose of the varobj if the type
1559 newobj = value_of_root (varp, &type_changed);
1560 if (update_type_if_necessary (*varp, newobj))
1561 type_changed = true;
1563 r.type_changed = type_changed;
1564 if (install_new_value ((*varp), newobj, type_changed))
1568 r.status = VAROBJ_NOT_IN_SCOPE;
1569 r.value_installed = true;
1571 if (r.status == VAROBJ_NOT_IN_SCOPE)
1573 if (r.type_changed || r.changed)
1574 result.push_back (std::move (r));
1579 stack.push_back (std::move (r));
1582 stack.emplace_back (*varp);
1584 /* Walk through the children, reconstructing them all. */
1585 while (!stack.empty ())
1587 varobj_update_result r = std::move (stack.back ());
1589 struct varobj *v = r.varobj;
1591 /* Update this variable, unless it's a root, which is already
1593 if (!r.value_installed)
1595 struct type *new_type;
1597 newobj = value_of_child (v->parent, v->index);
1598 if (update_type_if_necessary (v, newobj))
1599 r.type_changed = true;
1601 new_type = value_type (newobj);
1603 new_type = v->root->lang_ops->type_of_child (v->parent, v->index);
1605 if (varobj_value_has_mutated (v, newobj, new_type))
1607 /* The children are no longer valid; delete them now.
1608 Report the fact that its type changed as well. */
1609 varobj_delete (v, 1 /* only_children */);
1610 v->num_children = -1;
1614 r.type_changed = true;
1617 if (install_new_value (v, newobj, r.type_changed))
1624 /* We probably should not get children of a dynamic varobj, but
1625 for which -var-list-children was never invoked. */
1626 if (varobj_is_dynamic_p (v))
1628 std::vector<varobj *> changed, type_changed, unchanged, newobj;
1629 bool children_changed = false;
1634 if (!v->dynamic->children_requested)
1638 /* If we initially did not have potential children, but
1639 now we do, consider the varobj as changed.
1640 Otherwise, if children were never requested, consider
1641 it as unchanged -- presumably, such varobj is not yet
1642 expanded in the UI, so we need not bother getting
1644 if (!varobj_has_more (v, 0))
1646 update_dynamic_varobj_children (v, NULL, NULL, NULL, NULL,
1647 &dummy, false, 0, 0);
1648 if (varobj_has_more (v, 0))
1653 result.push_back (std::move (r));
1658 /* If update_dynamic_varobj_children returns false, then we have
1659 a non-conforming pretty-printer, so we skip it. */
1660 if (update_dynamic_varobj_children (v, &changed, &type_changed, &newobj,
1661 &unchanged, &children_changed, true,
1664 if (children_changed || !newobj.empty ())
1666 r.children_changed = true;
1667 r.newobj = std::move (newobj);
1669 /* Push in reverse order so that the first child is
1670 popped from the work stack first, and so will be
1671 added to result first. This does not affect
1672 correctness, just "nicer". */
1673 for (int i = type_changed.size () - 1; i >= 0; --i)
1675 varobj_update_result r (type_changed[i]);
1677 /* Type may change only if value was changed. */
1679 r.type_changed = true;
1680 r.value_installed = true;
1682 stack.push_back (std::move (r));
1684 for (int i = changed.size () - 1; i >= 0; --i)
1686 varobj_update_result r (changed[i]);
1689 r.value_installed = true;
1691 stack.push_back (std::move (r));
1693 for (int i = unchanged.size () - 1; i >= 0; --i)
1695 if (!unchanged[i]->frozen)
1697 varobj_update_result r (unchanged[i]);
1699 r.value_installed = true;
1701 stack.push_back (std::move (r));
1704 if (r.changed || r.children_changed)
1705 result.push_back (std::move (r));
1711 /* Push any children. Use reverse order so that the first
1712 child is popped from the work stack first, and so
1713 will be added to result first. This does not
1714 affect correctness, just "nicer". */
1715 for (int i = v->children.size () - 1; i >= 0; --i)
1717 varobj *c = v->children[i];
1719 /* Child may be NULL if explicitly deleted by -var-delete. */
1720 if (c != NULL && !c->frozen)
1721 stack.emplace_back (c);
1724 if (r.changed || r.type_changed)
1725 result.push_back (std::move (r));
1731 /* Helper functions */
1734 * Variable object construction/destruction
1738 delete_variable (struct varobj *var, bool only_children_p)
1742 delete_variable_1 (&delcount, var, only_children_p,
1743 true /* remove_from_parent_p */ );
1748 /* Delete the variable object VAR and its children. */
1749 /* IMPORTANT NOTE: If we delete a variable which is a child
1750 and the parent is not removed we dump core. It must be always
1751 initially called with remove_from_parent_p set. */
1753 delete_variable_1 (int *delcountp, struct varobj *var, bool only_children_p,
1754 bool remove_from_parent_p)
1756 /* Delete any children of this variable, too. */
1757 for (varobj *child : var->children)
1762 if (!remove_from_parent_p)
1763 child->parent = NULL;
1765 delete_variable_1 (delcountp, child, false, only_children_p);
1767 var->children.clear ();
1769 /* if we were called to delete only the children we are done here. */
1770 if (only_children_p)
1773 /* Otherwise, add it to the list of deleted ones and proceed to do so. */
1774 /* If the name is empty, this is a temporary variable, that has not
1775 yet been installed, don't report it, it belongs to the caller... */
1776 if (!var->obj_name.empty ())
1778 *delcountp = *delcountp + 1;
1781 /* If this variable has a parent, remove it from its parent's list. */
1782 /* OPTIMIZATION: if the parent of this variable is also being deleted,
1783 (as indicated by remove_from_parent_p) we don't bother doing an
1784 expensive list search to find the element to remove when we are
1785 discarding the list afterwards. */
1786 if ((remove_from_parent_p) && (var->parent != NULL))
1787 var->parent->children[var->index] = NULL;
1789 if (!var->obj_name.empty ())
1790 uninstall_variable (var);
1792 /* Free memory associated with this variable. */
1796 /* Install the given variable VAR with the object name VAR->OBJ_NAME. */
1798 install_variable (struct varobj *var)
1801 struct vlist *newvl;
1803 unsigned int index = 0;
1806 for (chp = var->obj_name.c_str (); *chp; chp++)
1808 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1811 cv = *(varobj_table + index);
1812 while (cv != NULL && cv->var->obj_name != var->obj_name)
1816 error (_("Duplicate variable object name"));
1818 /* Add varobj to hash table. */
1819 newvl = XNEW (struct vlist);
1820 newvl->next = *(varobj_table + index);
1822 *(varobj_table + index) = newvl;
1824 /* If root, add varobj to root list. */
1825 if (is_root_p (var))
1827 /* Add to list of root variables. */
1828 if (rootlist == NULL)
1829 var->root->next = NULL;
1831 var->root->next = rootlist;
1832 rootlist = var->root;
1835 return true; /* OK */
1838 /* Unistall the object VAR. */
1840 uninstall_variable (struct varobj *var)
1844 struct varobj_root *cr;
1845 struct varobj_root *prer;
1847 unsigned int index = 0;
1850 /* Remove varobj from hash table. */
1851 for (chp = var->obj_name.c_str (); *chp; chp++)
1853 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1856 cv = *(varobj_table + index);
1858 while (cv != NULL && cv->var->obj_name != var->obj_name)
1865 fprintf_unfiltered (gdb_stdlog, "Deleting %s\n", var->obj_name.c_str ());
1870 ("Assertion failed: Could not find variable object \"%s\" to delete",
1871 var->obj_name.c_str ());
1876 *(varobj_table + index) = cv->next;
1878 prev->next = cv->next;
1882 /* If root, remove varobj from root list. */
1883 if (is_root_p (var))
1885 /* Remove from list of root variables. */
1886 if (rootlist == var->root)
1887 rootlist = var->root->next;
1892 while ((cr != NULL) && (cr->rootvar != var))
1899 warning (_("Assertion failed: Could not find "
1900 "varobj \"%s\" in root list"),
1901 var->obj_name.c_str ());
1907 prer->next = cr->next;
1913 /* Create and install a child of the parent of the given name.
1915 The created VAROBJ takes ownership of the allocated NAME. */
1917 static struct varobj *
1918 create_child (struct varobj *parent, int index, std::string &name)
1920 struct varobj_item item;
1922 std::swap (item.name, name);
1923 item.value = value_of_child (parent, index);
1925 return create_child_with_value (parent, index, &item);
1928 static struct varobj *
1929 create_child_with_value (struct varobj *parent, int index,
1930 struct varobj_item *item)
1932 varobj *child = new varobj (parent->root);
1934 /* NAME is allocated by caller. */
1935 std::swap (child->name, item->name);
1936 child->index = index;
1937 child->parent = parent;
1939 if (varobj_is_anonymous_child (child))
1940 child->obj_name = string_printf ("%s.%d_anonymous",
1941 parent->obj_name.c_str (), index);
1943 child->obj_name = string_printf ("%s.%s",
1944 parent->obj_name.c_str (),
1945 child->name.c_str ());
1947 install_variable (child);
1949 /* Compute the type of the child. Must do this before
1950 calling install_new_value. */
1951 if (item->value != NULL)
1952 /* If the child had no evaluation errors, var->value
1953 will be non-NULL and contain a valid type. */
1954 child->type = value_actual_type (item->value, 0, NULL);
1956 /* Otherwise, we must compute the type. */
1957 child->type = (*child->root->lang_ops->type_of_child) (child->parent,
1959 install_new_value (child, item->value, 1);
1966 * Miscellaneous utility functions.
1969 /* Allocate memory and initialize a new variable. */
1970 varobj::varobj (varobj_root *root_)
1971 : root (root_), dynamic (new varobj_dynamic)
1975 /* Free any allocated memory associated with VAR. */
1982 if (var->dynamic->pretty_printer != NULL)
1984 gdbpy_enter_varobj enter_py (var);
1986 Py_XDECREF (var->dynamic->constructor);
1987 Py_XDECREF (var->dynamic->pretty_printer);
1991 varobj_iter_delete (var->dynamic->child_iter);
1992 varobj_clear_saved_item (var->dynamic);
1993 value_free (var->value);
1995 if (is_root_p (var))
1998 delete var->dynamic;
2001 /* Return the type of the value that's stored in VAR,
2002 or that would have being stored there if the
2003 value were accessible.
2005 This differs from VAR->type in that VAR->type is always
2006 the true type of the expession in the source language.
2007 The return value of this function is the type we're
2008 actually storing in varobj, and using for displaying
2009 the values and for comparing previous and new values.
2011 For example, top-level references are always stripped. */
2013 varobj_get_value_type (const struct varobj *var)
2018 type = value_type (var->value);
2022 type = check_typedef (type);
2024 if (TYPE_IS_REFERENCE (type))
2025 type = get_target_type (type);
2027 type = check_typedef (type);
2032 /* What is the default display for this variable? We assume that
2033 everything is "natural". Any exceptions? */
2034 static enum varobj_display_formats
2035 variable_default_display (struct varobj *var)
2037 return FORMAT_NATURAL;
2041 * Language-dependencies
2044 /* Common entry points */
2046 /* Return the number of children for a given variable.
2047 The result of this function is defined by the language
2048 implementation. The number of children returned by this function
2049 is the number of children that the user will see in the variable
2052 number_of_children (const struct varobj *var)
2054 return (*var->root->lang_ops->number_of_children) (var);
2057 /* What is the expression for the root varobj VAR? */
2060 name_of_variable (const struct varobj *var)
2062 return (*var->root->lang_ops->name_of_variable) (var);
2065 /* What is the name of the INDEX'th child of VAR? */
2068 name_of_child (struct varobj *var, int index)
2070 return (*var->root->lang_ops->name_of_child) (var, index);
2073 /* If frame associated with VAR can be found, switch
2074 to it and return true. Otherwise, return false. */
2077 check_scope (const struct varobj *var)
2079 struct frame_info *fi;
2082 fi = frame_find_by_id (var->root->frame);
2087 CORE_ADDR pc = get_frame_pc (fi);
2089 if (pc < BLOCK_START (var->root->valid_block) ||
2090 pc >= BLOCK_END (var->root->valid_block))
2098 /* Helper function to value_of_root. */
2100 static struct value *
2101 value_of_root_1 (struct varobj **var_handle)
2103 struct value *new_val = NULL;
2104 struct varobj *var = *var_handle;
2105 bool within_scope = false;
2107 /* Only root variables can be updated... */
2108 if (!is_root_p (var))
2109 /* Not a root var. */
2112 scoped_restore_current_thread restore_thread;
2114 /* Determine whether the variable is still around. */
2115 if (var->root->valid_block == NULL || var->root->floating)
2116 within_scope = true;
2117 else if (var->root->thread_id == 0)
2119 /* The program was single-threaded when the variable object was
2120 created. Technically, it's possible that the program became
2121 multi-threaded since then, but we don't support such
2123 within_scope = check_scope (var);
2127 ptid_t ptid = global_thread_id_to_ptid (var->root->thread_id);
2129 if (!ptid_equal (minus_one_ptid, ptid))
2131 switch_to_thread (ptid);
2132 within_scope = check_scope (var);
2139 /* We need to catch errors here, because if evaluate
2140 expression fails we want to just return NULL. */
2143 new_val = evaluate_expression (var->root->exp.get ());
2145 CATCH (except, RETURN_MASK_ERROR)
2154 /* What is the ``struct value *'' of the root variable VAR?
2155 For floating variable object, evaluation can get us a value
2156 of different type from what is stored in varobj already. In
2158 - *type_changed will be set to 1
2159 - old varobj will be freed, and new one will be
2160 created, with the same name.
2161 - *var_handle will be set to the new varobj
2162 Otherwise, *type_changed will be set to 0. */
2163 static struct value *
2164 value_of_root (struct varobj **var_handle, bool *type_changed)
2168 if (var_handle == NULL)
2173 /* This should really be an exception, since this should
2174 only get called with a root variable. */
2176 if (!is_root_p (var))
2179 if (var->root->floating)
2181 struct varobj *tmp_var;
2183 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2184 USE_SELECTED_FRAME);
2185 if (tmp_var == NULL)
2189 std::string old_type = varobj_get_type (var);
2190 std::string new_type = varobj_get_type (tmp_var);
2191 if (old_type == new_type)
2193 /* The expression presently stored inside var->root->exp
2194 remembers the locations of local variables relatively to
2195 the frame where the expression was created (in DWARF location
2196 button, for example). Naturally, those locations are not
2197 correct in other frames, so update the expression. */
2199 std::swap (var->root->exp, tmp_var->root->exp);
2201 varobj_delete (tmp_var, 0);
2206 tmp_var->obj_name = var->obj_name;
2207 tmp_var->from = var->from;
2208 tmp_var->to = var->to;
2209 varobj_delete (var, 0);
2211 install_variable (tmp_var);
2212 *var_handle = tmp_var;
2214 *type_changed = true;
2223 struct value *value;
2225 value = value_of_root_1 (var_handle);
2226 if (var->value == NULL || value == NULL)
2228 /* For root varobj-s, a NULL value indicates a scoping issue.
2229 So, nothing to do in terms of checking for mutations. */
2231 else if (varobj_value_has_mutated (var, value, value_type (value)))
2233 /* The type has mutated, so the children are no longer valid.
2234 Just delete them, and tell our caller that the type has
2236 varobj_delete (var, 1 /* only_children */);
2237 var->num_children = -1;
2240 *type_changed = true;
2246 /* What is the ``struct value *'' for the INDEX'th child of PARENT? */
2247 static struct value *
2248 value_of_child (const struct varobj *parent, int index)
2250 struct value *value;
2252 value = (*parent->root->lang_ops->value_of_child) (parent, index);
2257 /* GDB already has a command called "value_of_variable". Sigh. */
2259 my_value_of_variable (struct varobj *var, enum varobj_display_formats format)
2261 if (var->root->is_valid)
2263 if (var->dynamic->pretty_printer != NULL)
2264 return varobj_value_get_print_value (var->value, var->format, var);
2265 return (*var->root->lang_ops->value_of_variable) (var, format);
2268 return std::string ();
2272 varobj_formatted_print_options (struct value_print_options *opts,
2273 enum varobj_display_formats format)
2275 get_formatted_print_options (opts, format_code[(int) format]);
2276 opts->deref_ref = 0;
2277 opts->raw = !pretty_printing;
2281 varobj_value_get_print_value (struct value *value,
2282 enum varobj_display_formats format,
2283 const struct varobj *var)
2285 struct value_print_options opts;
2286 struct type *type = NULL;
2288 gdb::unique_xmalloc_ptr<char> encoding;
2289 /* Initialize it just to avoid a GCC false warning. */
2290 CORE_ADDR str_addr = 0;
2291 bool string_print = false;
2294 return std::string ();
2297 std::string thevalue;
2300 if (gdb_python_initialized)
2302 PyObject *value_formatter = var->dynamic->pretty_printer;
2304 gdbpy_enter_varobj enter_py (var);
2306 if (value_formatter)
2308 /* First check to see if we have any children at all. If so,
2309 we simply return {...}. */
2310 if (dynamic_varobj_has_child_method (var))
2313 if (PyObject_HasAttr (value_formatter, gdbpy_to_string_cst))
2315 struct value *replacement;
2317 gdbpy_ref<> output (apply_varobj_pretty_printer (value_formatter,
2321 /* If we have string like output ... */
2324 /* If this is a lazy string, extract it. For lazy
2325 strings we always print as a string, so set
2327 if (gdbpy_is_lazy_string (output.get ()))
2329 gdbpy_extract_lazy_string (output.get (), &str_addr,
2330 &type, &len, &encoding);
2331 string_print = true;
2335 /* If it is a regular (non-lazy) string, extract
2336 it and copy the contents into THEVALUE. If the
2337 hint says to print it as a string, set
2338 string_print. Otherwise just return the extracted
2339 string as a value. */
2341 gdb::unique_xmalloc_ptr<char> s
2342 = python_string_to_target_string (output.get ());
2346 struct gdbarch *gdbarch;
2348 gdb::unique_xmalloc_ptr<char> hint
2349 = gdbpy_get_display_hint (value_formatter);
2352 if (!strcmp (hint.get (), "string"))
2353 string_print = true;
2356 thevalue = std::string (s.get ());
2357 len = thevalue.size ();
2358 gdbarch = get_type_arch (value_type (value));
2359 type = builtin_type (gdbarch)->builtin_char;
2365 gdbpy_print_stack ();
2368 /* If the printer returned a replacement value, set VALUE
2369 to REPLACEMENT. If there is not a replacement value,
2370 just use the value passed to this function. */
2372 value = replacement;
2378 varobj_formatted_print_options (&opts, format);
2380 /* If the THEVALUE has contents, it is a regular string. */
2381 if (!thevalue.empty ())
2382 LA_PRINT_STRING (&stb, type, (gdb_byte *) thevalue.c_str (),
2383 len, encoding.get (), 0, &opts);
2384 else if (string_print)
2385 /* Otherwise, if string_print is set, and it is not a regular
2386 string, it is a lazy string. */
2387 val_print_string (type, encoding.get (), str_addr, len, &stb, &opts);
2389 /* All other cases. */
2390 common_val_print (value, &stb, 0, &opts, current_language);
2392 return std::move (stb.string ());
2396 varobj_editable_p (const struct varobj *var)
2400 if (!(var->root->is_valid && var->value && VALUE_LVAL (var->value)))
2403 type = varobj_get_value_type (var);
2405 switch (TYPE_CODE (type))
2407 case TYPE_CODE_STRUCT:
2408 case TYPE_CODE_UNION:
2409 case TYPE_CODE_ARRAY:
2410 case TYPE_CODE_FUNC:
2411 case TYPE_CODE_METHOD:
2421 /* Call VAR's value_is_changeable_p language-specific callback. */
2424 varobj_value_is_changeable_p (const struct varobj *var)
2426 return var->root->lang_ops->value_is_changeable_p (var);
2429 /* Return true if that varobj is floating, that is is always evaluated in the
2430 selected frame, and not bound to thread/frame. Such variable objects
2431 are created using '@' as frame specifier to -var-create. */
2433 varobj_floating_p (const struct varobj *var)
2435 return var->root->floating;
2438 /* Implement the "value_is_changeable_p" varobj callback for most
2442 varobj_default_value_is_changeable_p (const struct varobj *var)
2447 if (CPLUS_FAKE_CHILD (var))
2450 type = varobj_get_value_type (var);
2452 switch (TYPE_CODE (type))
2454 case TYPE_CODE_STRUCT:
2455 case TYPE_CODE_UNION:
2456 case TYPE_CODE_ARRAY:
2467 /* Iterate all the existing _root_ VAROBJs and call the FUNC callback for them
2468 with an arbitrary caller supplied DATA pointer. */
2471 all_root_varobjs (void (*func) (struct varobj *var, void *data), void *data)
2473 struct varobj_root *var_root, *var_root_next;
2475 /* Iterate "safely" - handle if the callee deletes its passed VAROBJ. */
2477 for (var_root = rootlist; var_root != NULL; var_root = var_root_next)
2479 var_root_next = var_root->next;
2481 (*func) (var_root->rootvar, data);
2485 /* Invalidate varobj VAR if it is tied to locals and re-create it if it is
2486 defined on globals. It is a helper for varobj_invalidate.
2488 This function is called after changing the symbol file, in this case the
2489 pointers to "struct type" stored by the varobj are no longer valid. All
2490 varobj must be either re-evaluated, or marked as invalid here. */
2493 varobj_invalidate_iter (struct varobj *var, void *unused)
2495 /* global and floating var must be re-evaluated. */
2496 if (var->root->floating || var->root->valid_block == NULL)
2498 struct varobj *tmp_var;
2500 /* Try to create a varobj with same expression. If we succeed
2501 replace the old varobj, otherwise invalidate it. */
2502 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2504 if (tmp_var != NULL)
2506 tmp_var->obj_name = var->obj_name;
2507 varobj_delete (var, 0);
2508 install_variable (tmp_var);
2511 var->root->is_valid = false;
2513 else /* locals must be invalidated. */
2514 var->root->is_valid = false;
2517 /* Invalidate the varobjs that are tied to locals and re-create the ones that
2518 are defined on globals.
2519 Invalidated varobjs will be always printed in_scope="invalid". */
2522 varobj_invalidate (void)
2524 all_root_varobjs (varobj_invalidate_iter, NULL);
2528 _initialize_varobj (void)
2530 varobj_table = XCNEWVEC (struct vlist *, VAROBJ_TABLE_SIZE);
2532 add_setshow_zuinteger_cmd ("varobj", class_maintenance,
2534 _("Set varobj debugging."),
2535 _("Show varobj debugging."),
2536 _("When non-zero, varobj debugging is enabled."),
2537 NULL, show_varobjdebug,
2538 &setdebuglist, &showdebuglist);