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 = inferior_thread ()->global_num;
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 != nullptr && !value_lazy (var->value.get ()))
527 var->print_value = varobj_value_get_print_value (var->value.get (),
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_decref (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 (item->value).release ();
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;
951 /* Computation of full rooted expression for children of dynamic
952 varobjs is not supported. */
953 if (varobj_is_dynamic_p (parent))
954 error (_("Invalid variable object (child of a dynamic varobj)"));
959 /* Return a pointer to the full rooted expression of varobj VAR.
960 If it has not been computed yet, compute it. */
963 varobj_get_path_expr (const struct varobj *var)
965 if (var->path_expr.empty ())
967 /* For root varobjs, we initialize path_expr
968 when creating varobj, so here it should be
970 struct varobj *mutable_var = (struct varobj *) var;
971 gdb_assert (!is_root_p (var));
973 mutable_var->path_expr = (*var->root->lang_ops->path_expr_of_child) (var);
976 return var->path_expr.c_str ();
979 const struct language_defn *
980 varobj_get_language (const struct varobj *var)
982 return var->root->exp->language_defn;
986 varobj_get_attributes (const struct varobj *var)
990 if (varobj_editable_p (var))
991 /* FIXME: define masks for attributes. */
992 attributes |= 0x00000001; /* Editable */
997 /* Return true if VAR is a dynamic varobj. */
1000 varobj_is_dynamic_p (const struct varobj *var)
1002 return var->dynamic->pretty_printer != NULL;
1006 varobj_get_formatted_value (struct varobj *var,
1007 enum varobj_display_formats format)
1009 return my_value_of_variable (var, format);
1013 varobj_get_value (struct varobj *var)
1015 return my_value_of_variable (var, var->format);
1018 /* Set the value of an object variable (if it is editable) to the
1019 value of the given expression. */
1020 /* Note: Invokes functions that can call error(). */
1023 varobj_set_value (struct varobj *var, const char *expression)
1025 struct value *val = NULL; /* Initialize to keep gcc happy. */
1026 /* The argument "expression" contains the variable's new value.
1027 We need to first construct a legal expression for this -- ugh! */
1028 /* Does this cover all the bases? */
1029 struct value *value = NULL; /* Initialize to keep gcc happy. */
1030 int saved_input_radix = input_radix;
1031 const char *s = expression;
1033 gdb_assert (varobj_editable_p (var));
1035 input_radix = 10; /* ALWAYS reset to decimal temporarily. */
1036 expression_up exp = parse_exp_1 (&s, 0, 0, 0);
1039 value = evaluate_expression (exp.get ());
1042 CATCH (except, RETURN_MASK_ERROR)
1044 /* We cannot proceed without a valid expression. */
1049 /* All types that are editable must also be changeable. */
1050 gdb_assert (varobj_value_is_changeable_p (var));
1052 /* The value of a changeable variable object must not be lazy. */
1053 gdb_assert (!value_lazy (var->value.get ()));
1055 /* Need to coerce the input. We want to check if the
1056 value of the variable object will be different
1057 after assignment, and the first thing value_assign
1058 does is coerce the input.
1059 For example, if we are assigning an array to a pointer variable we
1060 should compare the pointer with the array's address, not with the
1062 value = coerce_array (value);
1064 /* The new value may be lazy. value_assign, or
1065 rather value_contents, will take care of this. */
1068 val = value_assign (var->value.get (), value);
1071 CATCH (except, RETURN_MASK_ERROR)
1077 /* If the value has changed, record it, so that next -var-update can
1078 report this change. If a variable had a value of '1', we've set it
1079 to '333' and then set again to '1', when -var-update will report this
1080 variable as changed -- because the first assignment has set the
1081 'updated' flag. There's no need to optimize that, because return value
1082 of -var-update should be considered an approximation. */
1083 var->updated = install_new_value (var, val, false /* Compare values. */);
1084 input_radix = saved_input_radix;
1090 /* A helper function to install a constructor function and visualizer
1091 in a varobj_dynamic. */
1094 install_visualizer (struct varobj_dynamic *var, PyObject *constructor,
1095 PyObject *visualizer)
1097 Py_XDECREF (var->constructor);
1098 var->constructor = constructor;
1100 Py_XDECREF (var->pretty_printer);
1101 var->pretty_printer = visualizer;
1103 varobj_iter_delete (var->child_iter);
1104 var->child_iter = NULL;
1107 /* Install the default visualizer for VAR. */
1110 install_default_visualizer (struct varobj *var)
1112 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1113 if (CPLUS_FAKE_CHILD (var))
1116 if (pretty_printing)
1118 PyObject *pretty_printer = NULL;
1120 if (var->value != nullptr)
1122 pretty_printer = gdbpy_get_varobj_pretty_printer (var->value.get ());
1123 if (! pretty_printer)
1125 gdbpy_print_stack ();
1126 error (_("Cannot instantiate printer for default visualizer"));
1130 if (pretty_printer == Py_None)
1132 Py_DECREF (pretty_printer);
1133 pretty_printer = NULL;
1136 install_visualizer (var->dynamic, NULL, pretty_printer);
1140 /* Instantiate and install a visualizer for VAR using CONSTRUCTOR to
1141 make a new object. */
1144 construct_visualizer (struct varobj *var, PyObject *constructor)
1146 PyObject *pretty_printer;
1148 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1149 if (CPLUS_FAKE_CHILD (var))
1152 Py_INCREF (constructor);
1153 if (constructor == Py_None)
1154 pretty_printer = NULL;
1157 pretty_printer = instantiate_pretty_printer (constructor,
1159 if (! pretty_printer)
1161 gdbpy_print_stack ();
1162 Py_DECREF (constructor);
1163 constructor = Py_None;
1164 Py_INCREF (constructor);
1167 if (pretty_printer == Py_None)
1169 Py_DECREF (pretty_printer);
1170 pretty_printer = NULL;
1174 install_visualizer (var->dynamic, constructor, pretty_printer);
1177 #endif /* HAVE_PYTHON */
1179 /* A helper function for install_new_value. This creates and installs
1180 a visualizer for VAR, if appropriate. */
1183 install_new_value_visualizer (struct varobj *var)
1186 /* If the constructor is None, then we want the raw value. If VAR
1187 does not have a value, just skip this. */
1188 if (!gdb_python_initialized)
1191 if (var->dynamic->constructor != Py_None && var->value != NULL)
1193 gdbpy_enter_varobj enter_py (var);
1195 if (var->dynamic->constructor == NULL)
1196 install_default_visualizer (var);
1198 construct_visualizer (var, var->dynamic->constructor);
1205 /* When using RTTI to determine variable type it may be changed in runtime when
1206 the variable value is changed. This function checks whether type of varobj
1207 VAR will change when a new value NEW_VALUE is assigned and if it is so
1208 updates the type of VAR. */
1211 update_type_if_necessary (struct varobj *var, struct value *new_value)
1215 struct value_print_options opts;
1217 get_user_print_options (&opts);
1218 if (opts.objectprint)
1220 struct type *new_type = value_actual_type (new_value, 0, 0);
1221 std::string new_type_str = type_to_string (new_type);
1222 std::string curr_type_str = varobj_get_type (var);
1224 /* Did the type name change? */
1225 if (curr_type_str != new_type_str)
1227 var->type = new_type;
1229 /* This information may be not valid for a new type. */
1230 varobj_delete (var, 1);
1231 var->children.clear ();
1232 var->num_children = -1;
1241 /* Assign a new value to a variable object. If INITIAL is true,
1242 this is the first assignment after the variable object was just
1243 created, or changed type. In that case, just assign the value
1245 Otherwise, assign the new value, and return true if the value is
1246 different from the current one, false otherwise. The comparison is
1247 done on textual representation of value. Therefore, some types
1248 need not be compared. E.g. for structures the reported value is
1249 always "{...}", so no comparison is necessary here. If the old
1250 value was NULL and new one is not, or vice versa, we always return true.
1252 The VALUE parameter should not be released -- the function will
1253 take care of releasing it when needed. */
1255 install_new_value (struct varobj *var, struct value *value, bool initial)
1259 bool changed = false;
1260 bool intentionally_not_fetched = false;
1262 /* We need to know the varobj's type to decide if the value should
1263 be fetched or not. C++ fake children (public/protected/private)
1264 don't have a type. */
1265 gdb_assert (var->type || CPLUS_FAKE_CHILD (var));
1266 changeable = varobj_value_is_changeable_p (var);
1268 /* If the type has custom visualizer, we consider it to be always
1269 changeable. FIXME: need to make sure this behaviour will not
1270 mess up read-sensitive values. */
1271 if (var->dynamic->pretty_printer != NULL)
1274 need_to_fetch = changeable;
1276 /* We are not interested in the address of references, and given
1277 that in C++ a reference is not rebindable, it cannot
1278 meaningfully change. So, get hold of the real value. */
1280 value = coerce_ref (value);
1282 if (var->type && TYPE_CODE (var->type) == TYPE_CODE_UNION)
1283 /* For unions, we need to fetch the value implicitly because
1284 of implementation of union member fetch. When gdb
1285 creates a value for a field and the value of the enclosing
1286 structure is not lazy, it immediately copies the necessary
1287 bytes from the enclosing values. If the enclosing value is
1288 lazy, the call to value_fetch_lazy on the field will read
1289 the data from memory. For unions, that means we'll read the
1290 same memory more than once, which is not desirable. So
1292 need_to_fetch = true;
1294 /* The new value might be lazy. If the type is changeable,
1295 that is we'll be comparing values of this type, fetch the
1296 value now. Otherwise, on the next update the old value
1297 will be lazy, which means we've lost that old value. */
1298 if (need_to_fetch && value && value_lazy (value))
1300 const struct varobj *parent = var->parent;
1301 bool frozen = var->frozen;
1303 for (; !frozen && parent; parent = parent->parent)
1304 frozen |= parent->frozen;
1306 if (frozen && initial)
1308 /* For variables that are frozen, or are children of frozen
1309 variables, we don't do fetch on initial assignment.
1310 For non-initial assignemnt we do the fetch, since it means we're
1311 explicitly asked to compare the new value with the old one. */
1312 intentionally_not_fetched = true;
1319 value_fetch_lazy (value);
1322 CATCH (except, RETURN_MASK_ERROR)
1324 /* Set the value to NULL, so that for the next -var-update,
1325 we don't try to compare the new value with this value,
1326 that we couldn't even read. */
1333 /* Get a reference now, before possibly passing it to any Python
1334 code that might release it. */
1335 value_ref_ptr value_holder;
1337 value_holder = value_ref_ptr::new_reference (value);
1339 /* Below, we'll be comparing string rendering of old and new
1340 values. Don't get string rendering if the value is
1341 lazy -- if it is, the code above has decided that the value
1342 should not be fetched. */
1343 std::string print_value;
1344 if (value != NULL && !value_lazy (value)
1345 && var->dynamic->pretty_printer == NULL)
1346 print_value = varobj_value_get_print_value (value, var->format, var);
1348 /* If the type is changeable, compare the old and the new values.
1349 If this is the initial assignment, we don't have any old value
1351 if (!initial && changeable)
1353 /* If the value of the varobj was changed by -var-set-value,
1354 then the value in the varobj and in the target is the same.
1355 However, that value is different from the value that the
1356 varobj had after the previous -var-update. So need to the
1357 varobj as changed. */
1360 else if (var->dynamic->pretty_printer == NULL)
1362 /* Try to compare the values. That requires that both
1363 values are non-lazy. */
1364 if (var->not_fetched && value_lazy (var->value.get ()))
1366 /* This is a frozen varobj and the value was never read.
1367 Presumably, UI shows some "never read" indicator.
1368 Now that we've fetched the real value, we need to report
1369 this varobj as changed so that UI can show the real
1373 else if (var->value == NULL && value == NULL)
1376 else if (var->value == NULL || value == NULL)
1382 gdb_assert (!value_lazy (var->value.get ()));
1383 gdb_assert (!value_lazy (value));
1385 gdb_assert (!var->print_value.empty () && !print_value.empty ());
1386 if (var->print_value != print_value)
1392 if (!initial && !changeable)
1394 /* For values that are not changeable, we don't compare the values.
1395 However, we want to notice if a value was not NULL and now is NULL,
1396 or vise versa, so that we report when top-level varobjs come in scope
1397 and leave the scope. */
1398 changed = (var->value != NULL) != (value != NULL);
1401 /* We must always keep the new value, since children depend on it. */
1402 var->value = value_holder;
1403 if (value && value_lazy (value) && intentionally_not_fetched)
1404 var->not_fetched = true;
1406 var->not_fetched = false;
1407 var->updated = false;
1409 install_new_value_visualizer (var);
1411 /* If we installed a pretty-printer, re-compare the printed version
1412 to see if the variable changed. */
1413 if (var->dynamic->pretty_printer != NULL)
1415 print_value = varobj_value_get_print_value (var->value.get (),
1417 if ((var->print_value.empty () && !print_value.empty ())
1418 || (!var->print_value.empty () && print_value.empty ())
1419 || (!var->print_value.empty () && !print_value.empty ()
1420 && var->print_value != print_value))
1423 var->print_value = print_value;
1425 gdb_assert (var->value == nullptr || value_type (var->value.get ()));
1430 /* Return the requested range for a varobj. VAR is the varobj. FROM
1431 and TO are out parameters; *FROM and *TO will be set to the
1432 selected sub-range of VAR. If no range was selected using
1433 -var-set-update-range, then both will be -1. */
1435 varobj_get_child_range (const struct varobj *var, int *from, int *to)
1441 /* Set the selected sub-range of children of VAR to start at index
1442 FROM and end at index TO. If either FROM or TO is less than zero,
1443 this is interpreted as a request for all children. */
1445 varobj_set_child_range (struct varobj *var, int from, int to)
1452 varobj_set_visualizer (struct varobj *var, const char *visualizer)
1457 if (!gdb_python_initialized)
1460 gdbpy_enter_varobj enter_py (var);
1462 mainmod = PyImport_AddModule ("__main__");
1464 = gdbpy_ref<>::new_reference (PyModule_GetDict (mainmod));
1465 gdbpy_ref<> constructor (PyRun_String (visualizer, Py_eval_input,
1466 globals.get (), globals.get ()));
1468 if (constructor == NULL)
1470 gdbpy_print_stack ();
1471 error (_("Could not evaluate visualizer expression: %s"), visualizer);
1474 construct_visualizer (var, constructor.get ());
1476 /* If there are any children now, wipe them. */
1477 varobj_delete (var, 1 /* children only */);
1478 var->num_children = -1;
1480 error (_("Python support required"));
1484 /* If NEW_VALUE is the new value of the given varobj (var), return
1485 true if var has mutated. In other words, if the type of
1486 the new value is different from the type of the varobj's old
1489 NEW_VALUE may be NULL, if the varobj is now out of scope. */
1492 varobj_value_has_mutated (const struct varobj *var, struct value *new_value,
1493 struct type *new_type)
1495 /* If we haven't previously computed the number of children in var,
1496 it does not matter from the front-end's perspective whether
1497 the type has mutated or not. For all intents and purposes,
1498 it has not mutated. */
1499 if (var->num_children < 0)
1502 if (var->root->lang_ops->value_has_mutated != NULL)
1504 /* The varobj module, when installing new values, explicitly strips
1505 references, saying that we're not interested in those addresses.
1506 But detection of mutation happens before installing the new
1507 value, so our value may be a reference that we need to strip
1508 in order to remain consistent. */
1509 if (new_value != NULL)
1510 new_value = coerce_ref (new_value);
1511 return var->root->lang_ops->value_has_mutated (var, new_value, new_type);
1517 /* Update the values for a variable and its children. This is a
1518 two-pronged attack. First, re-parse the value for the root's
1519 expression to see if it's changed. Then go all the way
1520 through its children, reconstructing them and noting if they've
1523 The IS_EXPLICIT parameter specifies if this call is result
1524 of MI request to update this specific variable, or
1525 result of implicit -var-update *. For implicit request, we don't
1526 update frozen variables.
1528 NOTE: This function may delete the caller's varobj. If it
1529 returns TYPE_CHANGED, then it has done this and VARP will be modified
1530 to point to the new varobj. */
1532 std::vector<varobj_update_result>
1533 varobj_update (struct varobj **varp, bool is_explicit)
1535 bool type_changed = false;
1536 struct value *newobj;
1537 std::vector<varobj_update_result> stack;
1538 std::vector<varobj_update_result> result;
1540 /* Frozen means frozen -- we don't check for any change in
1541 this varobj, including its going out of scope, or
1542 changing type. One use case for frozen varobjs is
1543 retaining previously evaluated expressions, and we don't
1544 want them to be reevaluated at all. */
1545 if (!is_explicit && (*varp)->frozen)
1548 if (!(*varp)->root->is_valid)
1550 result.emplace_back (*varp, VAROBJ_INVALID);
1554 if ((*varp)->root->rootvar == *varp)
1556 varobj_update_result r (*varp);
1558 /* Update the root variable. value_of_root can return NULL
1559 if the variable is no longer around, i.e. we stepped out of
1560 the frame in which a local existed. We are letting the
1561 value_of_root variable dispose of the varobj if the type
1563 newobj = value_of_root (varp, &type_changed);
1564 if (update_type_if_necessary (*varp, newobj))
1565 type_changed = true;
1567 r.type_changed = type_changed;
1568 if (install_new_value ((*varp), newobj, type_changed))
1572 r.status = VAROBJ_NOT_IN_SCOPE;
1573 r.value_installed = true;
1575 if (r.status == VAROBJ_NOT_IN_SCOPE)
1577 if (r.type_changed || r.changed)
1578 result.push_back (std::move (r));
1583 stack.push_back (std::move (r));
1586 stack.emplace_back (*varp);
1588 /* Walk through the children, reconstructing them all. */
1589 while (!stack.empty ())
1591 varobj_update_result r = std::move (stack.back ());
1593 struct varobj *v = r.varobj;
1595 /* Update this variable, unless it's a root, which is already
1597 if (!r.value_installed)
1599 struct type *new_type;
1601 newobj = value_of_child (v->parent, v->index);
1602 if (update_type_if_necessary (v, newobj))
1603 r.type_changed = true;
1605 new_type = value_type (newobj);
1607 new_type = v->root->lang_ops->type_of_child (v->parent, v->index);
1609 if (varobj_value_has_mutated (v, newobj, new_type))
1611 /* The children are no longer valid; delete them now.
1612 Report the fact that its type changed as well. */
1613 varobj_delete (v, 1 /* only_children */);
1614 v->num_children = -1;
1618 r.type_changed = true;
1621 if (install_new_value (v, newobj, r.type_changed))
1628 /* We probably should not get children of a dynamic varobj, but
1629 for which -var-list-children was never invoked. */
1630 if (varobj_is_dynamic_p (v))
1632 std::vector<varobj *> changed, type_changed, unchanged, newobj;
1633 bool children_changed = false;
1638 if (!v->dynamic->children_requested)
1642 /* If we initially did not have potential children, but
1643 now we do, consider the varobj as changed.
1644 Otherwise, if children were never requested, consider
1645 it as unchanged -- presumably, such varobj is not yet
1646 expanded in the UI, so we need not bother getting
1648 if (!varobj_has_more (v, 0))
1650 update_dynamic_varobj_children (v, NULL, NULL, NULL, NULL,
1651 &dummy, false, 0, 0);
1652 if (varobj_has_more (v, 0))
1657 result.push_back (std::move (r));
1662 /* If update_dynamic_varobj_children returns false, then we have
1663 a non-conforming pretty-printer, so we skip it. */
1664 if (update_dynamic_varobj_children (v, &changed, &type_changed, &newobj,
1665 &unchanged, &children_changed, true,
1668 if (children_changed || !newobj.empty ())
1670 r.children_changed = true;
1671 r.newobj = std::move (newobj);
1673 /* Push in reverse order so that the first child is
1674 popped from the work stack first, and so will be
1675 added to result first. This does not affect
1676 correctness, just "nicer". */
1677 for (int i = type_changed.size () - 1; i >= 0; --i)
1679 varobj_update_result r (type_changed[i]);
1681 /* Type may change only if value was changed. */
1683 r.type_changed = true;
1684 r.value_installed = true;
1686 stack.push_back (std::move (r));
1688 for (int i = changed.size () - 1; i >= 0; --i)
1690 varobj_update_result r (changed[i]);
1693 r.value_installed = true;
1695 stack.push_back (std::move (r));
1697 for (int i = unchanged.size () - 1; i >= 0; --i)
1699 if (!unchanged[i]->frozen)
1701 varobj_update_result r (unchanged[i]);
1703 r.value_installed = true;
1705 stack.push_back (std::move (r));
1708 if (r.changed || r.children_changed)
1709 result.push_back (std::move (r));
1715 /* Push any children. Use reverse order so that the first
1716 child is popped from the work stack first, and so
1717 will be added to result first. This does not
1718 affect correctness, just "nicer". */
1719 for (int i = v->children.size () - 1; i >= 0; --i)
1721 varobj *c = v->children[i];
1723 /* Child may be NULL if explicitly deleted by -var-delete. */
1724 if (c != NULL && !c->frozen)
1725 stack.emplace_back (c);
1728 if (r.changed || r.type_changed)
1729 result.push_back (std::move (r));
1735 /* Helper functions */
1738 * Variable object construction/destruction
1742 delete_variable (struct varobj *var, bool only_children_p)
1746 delete_variable_1 (&delcount, var, only_children_p,
1747 true /* remove_from_parent_p */ );
1752 /* Delete the variable object VAR and its children. */
1753 /* IMPORTANT NOTE: If we delete a variable which is a child
1754 and the parent is not removed we dump core. It must be always
1755 initially called with remove_from_parent_p set. */
1757 delete_variable_1 (int *delcountp, struct varobj *var, bool only_children_p,
1758 bool remove_from_parent_p)
1760 /* Delete any children of this variable, too. */
1761 for (varobj *child : var->children)
1766 if (!remove_from_parent_p)
1767 child->parent = NULL;
1769 delete_variable_1 (delcountp, child, false, only_children_p);
1771 var->children.clear ();
1773 /* if we were called to delete only the children we are done here. */
1774 if (only_children_p)
1777 /* Otherwise, add it to the list of deleted ones and proceed to do so. */
1778 /* If the name is empty, this is a temporary variable, that has not
1779 yet been installed, don't report it, it belongs to the caller... */
1780 if (!var->obj_name.empty ())
1782 *delcountp = *delcountp + 1;
1785 /* If this variable has a parent, remove it from its parent's list. */
1786 /* OPTIMIZATION: if the parent of this variable is also being deleted,
1787 (as indicated by remove_from_parent_p) we don't bother doing an
1788 expensive list search to find the element to remove when we are
1789 discarding the list afterwards. */
1790 if ((remove_from_parent_p) && (var->parent != NULL))
1791 var->parent->children[var->index] = NULL;
1793 if (!var->obj_name.empty ())
1794 uninstall_variable (var);
1796 /* Free memory associated with this variable. */
1800 /* Install the given variable VAR with the object name VAR->OBJ_NAME. */
1802 install_variable (struct varobj *var)
1805 struct vlist *newvl;
1807 unsigned int index = 0;
1810 for (chp = var->obj_name.c_str (); *chp; chp++)
1812 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1815 cv = *(varobj_table + index);
1816 while (cv != NULL && cv->var->obj_name != var->obj_name)
1820 error (_("Duplicate variable object name"));
1822 /* Add varobj to hash table. */
1823 newvl = XNEW (struct vlist);
1824 newvl->next = *(varobj_table + index);
1826 *(varobj_table + index) = newvl;
1828 /* If root, add varobj to root list. */
1829 if (is_root_p (var))
1831 /* Add to list of root variables. */
1832 if (rootlist == NULL)
1833 var->root->next = NULL;
1835 var->root->next = rootlist;
1836 rootlist = var->root;
1839 return true; /* OK */
1842 /* Unistall the object VAR. */
1844 uninstall_variable (struct varobj *var)
1848 struct varobj_root *cr;
1849 struct varobj_root *prer;
1851 unsigned int index = 0;
1854 /* Remove varobj from hash table. */
1855 for (chp = var->obj_name.c_str (); *chp; chp++)
1857 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1860 cv = *(varobj_table + index);
1862 while (cv != NULL && cv->var->obj_name != var->obj_name)
1869 fprintf_unfiltered (gdb_stdlog, "Deleting %s\n", var->obj_name.c_str ());
1874 ("Assertion failed: Could not find variable object \"%s\" to delete",
1875 var->obj_name.c_str ());
1880 *(varobj_table + index) = cv->next;
1882 prev->next = cv->next;
1886 /* If root, remove varobj from root list. */
1887 if (is_root_p (var))
1889 /* Remove from list of root variables. */
1890 if (rootlist == var->root)
1891 rootlist = var->root->next;
1896 while ((cr != NULL) && (cr->rootvar != var))
1903 warning (_("Assertion failed: Could not find "
1904 "varobj \"%s\" in root list"),
1905 var->obj_name.c_str ());
1911 prer->next = cr->next;
1917 /* Create and install a child of the parent of the given name.
1919 The created VAROBJ takes ownership of the allocated NAME. */
1921 static struct varobj *
1922 create_child (struct varobj *parent, int index, std::string &name)
1924 struct varobj_item item;
1926 std::swap (item.name, name);
1927 item.value = value_of_child (parent, index);
1929 return create_child_with_value (parent, index, &item);
1932 static struct varobj *
1933 create_child_with_value (struct varobj *parent, int index,
1934 struct varobj_item *item)
1936 varobj *child = new varobj (parent->root);
1938 /* NAME is allocated by caller. */
1939 std::swap (child->name, item->name);
1940 child->index = index;
1941 child->parent = parent;
1943 if (varobj_is_anonymous_child (child))
1944 child->obj_name = string_printf ("%s.%d_anonymous",
1945 parent->obj_name.c_str (), index);
1947 child->obj_name = string_printf ("%s.%s",
1948 parent->obj_name.c_str (),
1949 child->name.c_str ());
1951 install_variable (child);
1953 /* Compute the type of the child. Must do this before
1954 calling install_new_value. */
1955 if (item->value != NULL)
1956 /* If the child had no evaluation errors, var->value
1957 will be non-NULL and contain a valid type. */
1958 child->type = value_actual_type (item->value, 0, NULL);
1960 /* Otherwise, we must compute the type. */
1961 child->type = (*child->root->lang_ops->type_of_child) (child->parent,
1963 install_new_value (child, item->value, 1);
1970 * Miscellaneous utility functions.
1973 /* Allocate memory and initialize a new variable. */
1974 varobj::varobj (varobj_root *root_)
1975 : root (root_), dynamic (new varobj_dynamic)
1979 /* Free any allocated memory associated with VAR. */
1986 if (var->dynamic->pretty_printer != NULL)
1988 gdbpy_enter_varobj enter_py (var);
1990 Py_XDECREF (var->dynamic->constructor);
1991 Py_XDECREF (var->dynamic->pretty_printer);
1995 varobj_iter_delete (var->dynamic->child_iter);
1996 varobj_clear_saved_item (var->dynamic);
1998 if (is_root_p (var))
2001 delete var->dynamic;
2004 /* Return the type of the value that's stored in VAR,
2005 or that would have being stored there if the
2006 value were accessible.
2008 This differs from VAR->type in that VAR->type is always
2009 the true type of the expession in the source language.
2010 The return value of this function is the type we're
2011 actually storing in varobj, and using for displaying
2012 the values and for comparing previous and new values.
2014 For example, top-level references are always stripped. */
2016 varobj_get_value_type (const struct varobj *var)
2020 if (var->value != nullptr)
2021 type = value_type (var->value.get ());
2025 type = check_typedef (type);
2027 if (TYPE_IS_REFERENCE (type))
2028 type = get_target_type (type);
2030 type = check_typedef (type);
2035 /* What is the default display for this variable? We assume that
2036 everything is "natural". Any exceptions? */
2037 static enum varobj_display_formats
2038 variable_default_display (struct varobj *var)
2040 return FORMAT_NATURAL;
2044 * Language-dependencies
2047 /* Common entry points */
2049 /* Return the number of children for a given variable.
2050 The result of this function is defined by the language
2051 implementation. The number of children returned by this function
2052 is the number of children that the user will see in the variable
2055 number_of_children (const struct varobj *var)
2057 return (*var->root->lang_ops->number_of_children) (var);
2060 /* What is the expression for the root varobj VAR? */
2063 name_of_variable (const struct varobj *var)
2065 return (*var->root->lang_ops->name_of_variable) (var);
2068 /* What is the name of the INDEX'th child of VAR? */
2071 name_of_child (struct varobj *var, int index)
2073 return (*var->root->lang_ops->name_of_child) (var, index);
2076 /* If frame associated with VAR can be found, switch
2077 to it and return true. Otherwise, return false. */
2080 check_scope (const struct varobj *var)
2082 struct frame_info *fi;
2085 fi = frame_find_by_id (var->root->frame);
2090 CORE_ADDR pc = get_frame_pc (fi);
2092 if (pc < BLOCK_START (var->root->valid_block) ||
2093 pc >= BLOCK_END (var->root->valid_block))
2101 /* Helper function to value_of_root. */
2103 static struct value *
2104 value_of_root_1 (struct varobj **var_handle)
2106 struct value *new_val = NULL;
2107 struct varobj *var = *var_handle;
2108 bool within_scope = false;
2110 /* Only root variables can be updated... */
2111 if (!is_root_p (var))
2112 /* Not a root var. */
2115 scoped_restore_current_thread restore_thread;
2117 /* Determine whether the variable is still around. */
2118 if (var->root->valid_block == NULL || var->root->floating)
2119 within_scope = true;
2120 else if (var->root->thread_id == 0)
2122 /* The program was single-threaded when the variable object was
2123 created. Technically, it's possible that the program became
2124 multi-threaded since then, but we don't support such
2126 within_scope = check_scope (var);
2130 thread_info *thread = find_thread_global_id (var->root->thread_id);
2134 switch_to_thread (thread);
2135 within_scope = check_scope (var);
2142 /* We need to catch errors here, because if evaluate
2143 expression fails we want to just return NULL. */
2146 new_val = evaluate_expression (var->root->exp.get ());
2148 CATCH (except, RETURN_MASK_ERROR)
2157 /* What is the ``struct value *'' of the root variable VAR?
2158 For floating variable object, evaluation can get us a value
2159 of different type from what is stored in varobj already. In
2161 - *type_changed will be set to 1
2162 - old varobj will be freed, and new one will be
2163 created, with the same name.
2164 - *var_handle will be set to the new varobj
2165 Otherwise, *type_changed will be set to 0. */
2166 static struct value *
2167 value_of_root (struct varobj **var_handle, bool *type_changed)
2171 if (var_handle == NULL)
2176 /* This should really be an exception, since this should
2177 only get called with a root variable. */
2179 if (!is_root_p (var))
2182 if (var->root->floating)
2184 struct varobj *tmp_var;
2186 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2187 USE_SELECTED_FRAME);
2188 if (tmp_var == NULL)
2192 std::string old_type = varobj_get_type (var);
2193 std::string new_type = varobj_get_type (tmp_var);
2194 if (old_type == new_type)
2196 /* The expression presently stored inside var->root->exp
2197 remembers the locations of local variables relatively to
2198 the frame where the expression was created (in DWARF location
2199 button, for example). Naturally, those locations are not
2200 correct in other frames, so update the expression. */
2202 std::swap (var->root->exp, tmp_var->root->exp);
2204 varobj_delete (tmp_var, 0);
2209 tmp_var->obj_name = var->obj_name;
2210 tmp_var->from = var->from;
2211 tmp_var->to = var->to;
2212 varobj_delete (var, 0);
2214 install_variable (tmp_var);
2215 *var_handle = tmp_var;
2217 *type_changed = true;
2226 struct value *value;
2228 value = value_of_root_1 (var_handle);
2229 if (var->value == NULL || value == NULL)
2231 /* For root varobj-s, a NULL value indicates a scoping issue.
2232 So, nothing to do in terms of checking for mutations. */
2234 else if (varobj_value_has_mutated (var, value, value_type (value)))
2236 /* The type has mutated, so the children are no longer valid.
2237 Just delete them, and tell our caller that the type has
2239 varobj_delete (var, 1 /* only_children */);
2240 var->num_children = -1;
2243 *type_changed = true;
2249 /* What is the ``struct value *'' for the INDEX'th child of PARENT? */
2250 static struct value *
2251 value_of_child (const struct varobj *parent, int index)
2253 struct value *value;
2255 value = (*parent->root->lang_ops->value_of_child) (parent, index);
2260 /* GDB already has a command called "value_of_variable". Sigh. */
2262 my_value_of_variable (struct varobj *var, enum varobj_display_formats format)
2264 if (var->root->is_valid)
2266 if (var->dynamic->pretty_printer != NULL)
2267 return varobj_value_get_print_value (var->value.get (), var->format,
2269 return (*var->root->lang_ops->value_of_variable) (var, format);
2272 return std::string ();
2276 varobj_formatted_print_options (struct value_print_options *opts,
2277 enum varobj_display_formats format)
2279 get_formatted_print_options (opts, format_code[(int) format]);
2280 opts->deref_ref = 0;
2281 opts->raw = !pretty_printing;
2285 varobj_value_get_print_value (struct value *value,
2286 enum varobj_display_formats format,
2287 const struct varobj *var)
2289 struct value_print_options opts;
2290 struct type *type = NULL;
2292 gdb::unique_xmalloc_ptr<char> encoding;
2293 /* Initialize it just to avoid a GCC false warning. */
2294 CORE_ADDR str_addr = 0;
2295 bool string_print = false;
2298 return std::string ();
2301 std::string thevalue;
2304 if (gdb_python_initialized)
2306 PyObject *value_formatter = var->dynamic->pretty_printer;
2308 gdbpy_enter_varobj enter_py (var);
2310 if (value_formatter)
2312 /* First check to see if we have any children at all. If so,
2313 we simply return {...}. */
2314 if (dynamic_varobj_has_child_method (var))
2317 if (PyObject_HasAttr (value_formatter, gdbpy_to_string_cst))
2319 struct value *replacement;
2321 gdbpy_ref<> output (apply_varobj_pretty_printer (value_formatter,
2325 /* If we have string like output ... */
2328 /* If this is a lazy string, extract it. For lazy
2329 strings we always print as a string, so set
2331 if (gdbpy_is_lazy_string (output.get ()))
2333 gdbpy_extract_lazy_string (output.get (), &str_addr,
2334 &type, &len, &encoding);
2335 string_print = true;
2339 /* If it is a regular (non-lazy) string, extract
2340 it and copy the contents into THEVALUE. If the
2341 hint says to print it as a string, set
2342 string_print. Otherwise just return the extracted
2343 string as a value. */
2345 gdb::unique_xmalloc_ptr<char> s
2346 = python_string_to_target_string (output.get ());
2350 struct gdbarch *gdbarch;
2352 gdb::unique_xmalloc_ptr<char> hint
2353 = gdbpy_get_display_hint (value_formatter);
2356 if (!strcmp (hint.get (), "string"))
2357 string_print = true;
2360 thevalue = std::string (s.get ());
2361 len = thevalue.size ();
2362 gdbarch = get_type_arch (value_type (value));
2363 type = builtin_type (gdbarch)->builtin_char;
2369 gdbpy_print_stack ();
2372 /* If the printer returned a replacement value, set VALUE
2373 to REPLACEMENT. If there is not a replacement value,
2374 just use the value passed to this function. */
2376 value = replacement;
2382 varobj_formatted_print_options (&opts, format);
2384 /* If the THEVALUE has contents, it is a regular string. */
2385 if (!thevalue.empty ())
2386 LA_PRINT_STRING (&stb, type, (gdb_byte *) thevalue.c_str (),
2387 len, encoding.get (), 0, &opts);
2388 else if (string_print)
2389 /* Otherwise, if string_print is set, and it is not a regular
2390 string, it is a lazy string. */
2391 val_print_string (type, encoding.get (), str_addr, len, &stb, &opts);
2393 /* All other cases. */
2394 common_val_print (value, &stb, 0, &opts, current_language);
2396 return std::move (stb.string ());
2400 varobj_editable_p (const struct varobj *var)
2404 if (!(var->root->is_valid && var->value != nullptr
2405 && VALUE_LVAL (var->value.get ())))
2408 type = varobj_get_value_type (var);
2410 switch (TYPE_CODE (type))
2412 case TYPE_CODE_STRUCT:
2413 case TYPE_CODE_UNION:
2414 case TYPE_CODE_ARRAY:
2415 case TYPE_CODE_FUNC:
2416 case TYPE_CODE_METHOD:
2426 /* Call VAR's value_is_changeable_p language-specific callback. */
2429 varobj_value_is_changeable_p (const struct varobj *var)
2431 return var->root->lang_ops->value_is_changeable_p (var);
2434 /* Return true if that varobj is floating, that is is always evaluated in the
2435 selected frame, and not bound to thread/frame. Such variable objects
2436 are created using '@' as frame specifier to -var-create. */
2438 varobj_floating_p (const struct varobj *var)
2440 return var->root->floating;
2443 /* Implement the "value_is_changeable_p" varobj callback for most
2447 varobj_default_value_is_changeable_p (const struct varobj *var)
2452 if (CPLUS_FAKE_CHILD (var))
2455 type = varobj_get_value_type (var);
2457 switch (TYPE_CODE (type))
2459 case TYPE_CODE_STRUCT:
2460 case TYPE_CODE_UNION:
2461 case TYPE_CODE_ARRAY:
2472 /* Iterate all the existing _root_ VAROBJs and call the FUNC callback for them
2473 with an arbitrary caller supplied DATA pointer. */
2476 all_root_varobjs (void (*func) (struct varobj *var, void *data), void *data)
2478 struct varobj_root *var_root, *var_root_next;
2480 /* Iterate "safely" - handle if the callee deletes its passed VAROBJ. */
2482 for (var_root = rootlist; var_root != NULL; var_root = var_root_next)
2484 var_root_next = var_root->next;
2486 (*func) (var_root->rootvar, data);
2490 /* Invalidate varobj VAR if it is tied to locals and re-create it if it is
2491 defined on globals. It is a helper for varobj_invalidate.
2493 This function is called after changing the symbol file, in this case the
2494 pointers to "struct type" stored by the varobj are no longer valid. All
2495 varobj must be either re-evaluated, or marked as invalid here. */
2498 varobj_invalidate_iter (struct varobj *var, void *unused)
2500 /* global and floating var must be re-evaluated. */
2501 if (var->root->floating || var->root->valid_block == NULL)
2503 struct varobj *tmp_var;
2505 /* Try to create a varobj with same expression. If we succeed
2506 replace the old varobj, otherwise invalidate it. */
2507 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2509 if (tmp_var != NULL)
2511 tmp_var->obj_name = var->obj_name;
2512 varobj_delete (var, 0);
2513 install_variable (tmp_var);
2516 var->root->is_valid = false;
2518 else /* locals must be invalidated. */
2519 var->root->is_valid = false;
2522 /* Invalidate the varobjs that are tied to locals and re-create the ones that
2523 are defined on globals.
2524 Invalidated varobjs will be always printed in_scope="invalid". */
2527 varobj_invalidate (void)
2529 all_root_varobjs (varobj_invalidate_iter, NULL);
2533 _initialize_varobj (void)
2535 varobj_table = XCNEWVEC (struct vlist *, VAROBJ_TABLE_SIZE);
2537 add_setshow_zuinteger_cmd ("varobj", class_maintenance,
2539 _("Set varobj debugging."),
2540 _("Show varobj debugging."),
2541 _("When non-zero, varobj debugging is enabled."),
2542 NULL, show_varobjdebug,
2543 &setdebuglist, &showdebuglist);