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 gdbpy_ref<> pretty_printer;
1120 if (var->value != nullptr)
1122 pretty_printer = gdbpy_get_varobj_pretty_printer (var->value.get ());
1123 if (pretty_printer == nullptr)
1125 gdbpy_print_stack ();
1126 error (_("Cannot instantiate printer for default visualizer"));
1130 if (pretty_printer == Py_None)
1131 pretty_printer.release ();
1133 install_visualizer (var->dynamic, NULL, pretty_printer.release ());
1137 /* Instantiate and install a visualizer for VAR using CONSTRUCTOR to
1138 make a new object. */
1141 construct_visualizer (struct varobj *var, PyObject *constructor)
1143 PyObject *pretty_printer;
1145 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1146 if (CPLUS_FAKE_CHILD (var))
1149 Py_INCREF (constructor);
1150 if (constructor == Py_None)
1151 pretty_printer = NULL;
1154 pretty_printer = instantiate_pretty_printer (constructor,
1156 if (! pretty_printer)
1158 gdbpy_print_stack ();
1159 Py_DECREF (constructor);
1160 constructor = Py_None;
1161 Py_INCREF (constructor);
1164 if (pretty_printer == Py_None)
1166 Py_DECREF (pretty_printer);
1167 pretty_printer = NULL;
1171 install_visualizer (var->dynamic, constructor, pretty_printer);
1174 #endif /* HAVE_PYTHON */
1176 /* A helper function for install_new_value. This creates and installs
1177 a visualizer for VAR, if appropriate. */
1180 install_new_value_visualizer (struct varobj *var)
1183 /* If the constructor is None, then we want the raw value. If VAR
1184 does not have a value, just skip this. */
1185 if (!gdb_python_initialized)
1188 if (var->dynamic->constructor != Py_None && var->value != NULL)
1190 gdbpy_enter_varobj enter_py (var);
1192 if (var->dynamic->constructor == NULL)
1193 install_default_visualizer (var);
1195 construct_visualizer (var, var->dynamic->constructor);
1202 /* When using RTTI to determine variable type it may be changed in runtime when
1203 the variable value is changed. This function checks whether type of varobj
1204 VAR will change when a new value NEW_VALUE is assigned and if it is so
1205 updates the type of VAR. */
1208 update_type_if_necessary (struct varobj *var, struct value *new_value)
1212 struct value_print_options opts;
1214 get_user_print_options (&opts);
1215 if (opts.objectprint)
1217 struct type *new_type = value_actual_type (new_value, 0, 0);
1218 std::string new_type_str = type_to_string (new_type);
1219 std::string curr_type_str = varobj_get_type (var);
1221 /* Did the type name change? */
1222 if (curr_type_str != new_type_str)
1224 var->type = new_type;
1226 /* This information may be not valid for a new type. */
1227 varobj_delete (var, 1);
1228 var->children.clear ();
1229 var->num_children = -1;
1238 /* Assign a new value to a variable object. If INITIAL is true,
1239 this is the first assignment after the variable object was just
1240 created, or changed type. In that case, just assign the value
1242 Otherwise, assign the new value, and return true if the value is
1243 different from the current one, false otherwise. The comparison is
1244 done on textual representation of value. Therefore, some types
1245 need not be compared. E.g. for structures the reported value is
1246 always "{...}", so no comparison is necessary here. If the old
1247 value was NULL and new one is not, or vice versa, we always return true.
1249 The VALUE parameter should not be released -- the function will
1250 take care of releasing it when needed. */
1252 install_new_value (struct varobj *var, struct value *value, bool initial)
1256 bool changed = false;
1257 bool intentionally_not_fetched = false;
1259 /* We need to know the varobj's type to decide if the value should
1260 be fetched or not. C++ fake children (public/protected/private)
1261 don't have a type. */
1262 gdb_assert (var->type || CPLUS_FAKE_CHILD (var));
1263 changeable = varobj_value_is_changeable_p (var);
1265 /* If the type has custom visualizer, we consider it to be always
1266 changeable. FIXME: need to make sure this behaviour will not
1267 mess up read-sensitive values. */
1268 if (var->dynamic->pretty_printer != NULL)
1271 need_to_fetch = changeable;
1273 /* We are not interested in the address of references, and given
1274 that in C++ a reference is not rebindable, it cannot
1275 meaningfully change. So, get hold of the real value. */
1277 value = coerce_ref (value);
1279 if (var->type && TYPE_CODE (var->type) == TYPE_CODE_UNION)
1280 /* For unions, we need to fetch the value implicitly because
1281 of implementation of union member fetch. When gdb
1282 creates a value for a field and the value of the enclosing
1283 structure is not lazy, it immediately copies the necessary
1284 bytes from the enclosing values. If the enclosing value is
1285 lazy, the call to value_fetch_lazy on the field will read
1286 the data from memory. For unions, that means we'll read the
1287 same memory more than once, which is not desirable. So
1289 need_to_fetch = true;
1291 /* The new value might be lazy. If the type is changeable,
1292 that is we'll be comparing values of this type, fetch the
1293 value now. Otherwise, on the next update the old value
1294 will be lazy, which means we've lost that old value. */
1295 if (need_to_fetch && value && value_lazy (value))
1297 const struct varobj *parent = var->parent;
1298 bool frozen = var->frozen;
1300 for (; !frozen && parent; parent = parent->parent)
1301 frozen |= parent->frozen;
1303 if (frozen && initial)
1305 /* For variables that are frozen, or are children of frozen
1306 variables, we don't do fetch on initial assignment.
1307 For non-initial assignemnt we do the fetch, since it means we're
1308 explicitly asked to compare the new value with the old one. */
1309 intentionally_not_fetched = true;
1316 value_fetch_lazy (value);
1319 CATCH (except, RETURN_MASK_ERROR)
1321 /* Set the value to NULL, so that for the next -var-update,
1322 we don't try to compare the new value with this value,
1323 that we couldn't even read. */
1330 /* Get a reference now, before possibly passing it to any Python
1331 code that might release it. */
1332 value_ref_ptr value_holder;
1334 value_holder = value_ref_ptr::new_reference (value);
1336 /* Below, we'll be comparing string rendering of old and new
1337 values. Don't get string rendering if the value is
1338 lazy -- if it is, the code above has decided that the value
1339 should not be fetched. */
1340 std::string print_value;
1341 if (value != NULL && !value_lazy (value)
1342 && var->dynamic->pretty_printer == NULL)
1343 print_value = varobj_value_get_print_value (value, var->format, var);
1345 /* If the type is changeable, compare the old and the new values.
1346 If this is the initial assignment, we don't have any old value
1348 if (!initial && changeable)
1350 /* If the value of the varobj was changed by -var-set-value,
1351 then the value in the varobj and in the target is the same.
1352 However, that value is different from the value that the
1353 varobj had after the previous -var-update. So need to the
1354 varobj as changed. */
1357 else if (var->dynamic->pretty_printer == NULL)
1359 /* Try to compare the values. That requires that both
1360 values are non-lazy. */
1361 if (var->not_fetched && value_lazy (var->value.get ()))
1363 /* This is a frozen varobj and the value was never read.
1364 Presumably, UI shows some "never read" indicator.
1365 Now that we've fetched the real value, we need to report
1366 this varobj as changed so that UI can show the real
1370 else if (var->value == NULL && value == NULL)
1373 else if (var->value == NULL || value == NULL)
1379 gdb_assert (!value_lazy (var->value.get ()));
1380 gdb_assert (!value_lazy (value));
1382 gdb_assert (!var->print_value.empty () && !print_value.empty ());
1383 if (var->print_value != print_value)
1389 if (!initial && !changeable)
1391 /* For values that are not changeable, we don't compare the values.
1392 However, we want to notice if a value was not NULL and now is NULL,
1393 or vise versa, so that we report when top-level varobjs come in scope
1394 and leave the scope. */
1395 changed = (var->value != NULL) != (value != NULL);
1398 /* We must always keep the new value, since children depend on it. */
1399 var->value = value_holder;
1400 if (value && value_lazy (value) && intentionally_not_fetched)
1401 var->not_fetched = true;
1403 var->not_fetched = false;
1404 var->updated = false;
1406 install_new_value_visualizer (var);
1408 /* If we installed a pretty-printer, re-compare the printed version
1409 to see if the variable changed. */
1410 if (var->dynamic->pretty_printer != NULL)
1412 print_value = varobj_value_get_print_value (var->value.get (),
1414 if ((var->print_value.empty () && !print_value.empty ())
1415 || (!var->print_value.empty () && print_value.empty ())
1416 || (!var->print_value.empty () && !print_value.empty ()
1417 && var->print_value != print_value))
1420 var->print_value = print_value;
1422 gdb_assert (var->value == nullptr || value_type (var->value.get ()));
1427 /* Return the requested range for a varobj. VAR is the varobj. FROM
1428 and TO are out parameters; *FROM and *TO will be set to the
1429 selected sub-range of VAR. If no range was selected using
1430 -var-set-update-range, then both will be -1. */
1432 varobj_get_child_range (const struct varobj *var, int *from, int *to)
1438 /* Set the selected sub-range of children of VAR to start at index
1439 FROM and end at index TO. If either FROM or TO is less than zero,
1440 this is interpreted as a request for all children. */
1442 varobj_set_child_range (struct varobj *var, int from, int to)
1449 varobj_set_visualizer (struct varobj *var, const char *visualizer)
1454 if (!gdb_python_initialized)
1457 gdbpy_enter_varobj enter_py (var);
1459 mainmod = PyImport_AddModule ("__main__");
1461 = gdbpy_ref<>::new_reference (PyModule_GetDict (mainmod));
1462 gdbpy_ref<> constructor (PyRun_String (visualizer, Py_eval_input,
1463 globals.get (), globals.get ()));
1465 if (constructor == NULL)
1467 gdbpy_print_stack ();
1468 error (_("Could not evaluate visualizer expression: %s"), visualizer);
1471 construct_visualizer (var, constructor.get ());
1473 /* If there are any children now, wipe them. */
1474 varobj_delete (var, 1 /* children only */);
1475 var->num_children = -1;
1477 error (_("Python support required"));
1481 /* If NEW_VALUE is the new value of the given varobj (var), return
1482 true if var has mutated. In other words, if the type of
1483 the new value is different from the type of the varobj's old
1486 NEW_VALUE may be NULL, if the varobj is now out of scope. */
1489 varobj_value_has_mutated (const struct varobj *var, struct value *new_value,
1490 struct type *new_type)
1492 /* If we haven't previously computed the number of children in var,
1493 it does not matter from the front-end's perspective whether
1494 the type has mutated or not. For all intents and purposes,
1495 it has not mutated. */
1496 if (var->num_children < 0)
1499 if (var->root->lang_ops->value_has_mutated != NULL)
1501 /* The varobj module, when installing new values, explicitly strips
1502 references, saying that we're not interested in those addresses.
1503 But detection of mutation happens before installing the new
1504 value, so our value may be a reference that we need to strip
1505 in order to remain consistent. */
1506 if (new_value != NULL)
1507 new_value = coerce_ref (new_value);
1508 return var->root->lang_ops->value_has_mutated (var, new_value, new_type);
1514 /* Update the values for a variable and its children. This is a
1515 two-pronged attack. First, re-parse the value for the root's
1516 expression to see if it's changed. Then go all the way
1517 through its children, reconstructing them and noting if they've
1520 The IS_EXPLICIT parameter specifies if this call is result
1521 of MI request to update this specific variable, or
1522 result of implicit -var-update *. For implicit request, we don't
1523 update frozen variables.
1525 NOTE: This function may delete the caller's varobj. If it
1526 returns TYPE_CHANGED, then it has done this and VARP will be modified
1527 to point to the new varobj. */
1529 std::vector<varobj_update_result>
1530 varobj_update (struct varobj **varp, bool is_explicit)
1532 bool type_changed = false;
1533 struct value *newobj;
1534 std::vector<varobj_update_result> stack;
1535 std::vector<varobj_update_result> result;
1537 /* Frozen means frozen -- we don't check for any change in
1538 this varobj, including its going out of scope, or
1539 changing type. One use case for frozen varobjs is
1540 retaining previously evaluated expressions, and we don't
1541 want them to be reevaluated at all. */
1542 if (!is_explicit && (*varp)->frozen)
1545 if (!(*varp)->root->is_valid)
1547 result.emplace_back (*varp, VAROBJ_INVALID);
1551 if ((*varp)->root->rootvar == *varp)
1553 varobj_update_result r (*varp);
1555 /* Update the root variable. value_of_root can return NULL
1556 if the variable is no longer around, i.e. we stepped out of
1557 the frame in which a local existed. We are letting the
1558 value_of_root variable dispose of the varobj if the type
1560 newobj = value_of_root (varp, &type_changed);
1561 if (update_type_if_necessary (*varp, newobj))
1562 type_changed = true;
1564 r.type_changed = type_changed;
1565 if (install_new_value ((*varp), newobj, type_changed))
1569 r.status = VAROBJ_NOT_IN_SCOPE;
1570 r.value_installed = true;
1572 if (r.status == VAROBJ_NOT_IN_SCOPE)
1574 if (r.type_changed || r.changed)
1575 result.push_back (std::move (r));
1580 stack.push_back (std::move (r));
1583 stack.emplace_back (*varp);
1585 /* Walk through the children, reconstructing them all. */
1586 while (!stack.empty ())
1588 varobj_update_result r = std::move (stack.back ());
1590 struct varobj *v = r.varobj;
1592 /* Update this variable, unless it's a root, which is already
1594 if (!r.value_installed)
1596 struct type *new_type;
1598 newobj = value_of_child (v->parent, v->index);
1599 if (update_type_if_necessary (v, newobj))
1600 r.type_changed = true;
1602 new_type = value_type (newobj);
1604 new_type = v->root->lang_ops->type_of_child (v->parent, v->index);
1606 if (varobj_value_has_mutated (v, newobj, new_type))
1608 /* The children are no longer valid; delete them now.
1609 Report the fact that its type changed as well. */
1610 varobj_delete (v, 1 /* only_children */);
1611 v->num_children = -1;
1615 r.type_changed = true;
1618 if (install_new_value (v, newobj, r.type_changed))
1625 /* We probably should not get children of a dynamic varobj, but
1626 for which -var-list-children was never invoked. */
1627 if (varobj_is_dynamic_p (v))
1629 std::vector<varobj *> changed, type_changed_vec, unchanged, newobj_vec;
1630 bool children_changed = false;
1635 if (!v->dynamic->children_requested)
1639 /* If we initially did not have potential children, but
1640 now we do, consider the varobj as changed.
1641 Otherwise, if children were never requested, consider
1642 it as unchanged -- presumably, such varobj is not yet
1643 expanded in the UI, so we need not bother getting
1645 if (!varobj_has_more (v, 0))
1647 update_dynamic_varobj_children (v, NULL, NULL, NULL, NULL,
1648 &dummy, false, 0, 0);
1649 if (varobj_has_more (v, 0))
1654 result.push_back (std::move (r));
1659 /* If update_dynamic_varobj_children returns false, then we have
1660 a non-conforming pretty-printer, so we skip it. */
1661 if (update_dynamic_varobj_children (v, &changed, &type_changed_vec,
1663 &unchanged, &children_changed,
1664 true, v->from, v->to))
1666 if (children_changed || !newobj_vec.empty ())
1668 r.children_changed = true;
1669 r.newobj = std::move (newobj_vec);
1671 /* Push in reverse order so that the first child is
1672 popped from the work stack first, and so will be
1673 added to result first. This does not affect
1674 correctness, just "nicer". */
1675 for (int i = type_changed_vec.size () - 1; i >= 0; --i)
1677 varobj_update_result item (type_changed_vec[i]);
1679 /* Type may change only if value was changed. */
1680 item.changed = true;
1681 item.type_changed = true;
1682 item.value_installed = true;
1684 stack.push_back (std::move (item));
1686 for (int i = changed.size () - 1; i >= 0; --i)
1688 varobj_update_result item (changed[i]);
1690 item.changed = true;
1691 item.value_installed = true;
1693 stack.push_back (std::move (item));
1695 for (int i = unchanged.size () - 1; i >= 0; --i)
1697 if (!unchanged[i]->frozen)
1699 varobj_update_result item (unchanged[i]);
1701 item.value_installed = true;
1703 stack.push_back (std::move (item));
1706 if (r.changed || r.children_changed)
1707 result.push_back (std::move (r));
1713 /* Push any children. Use reverse order so that the first
1714 child is popped from the work stack first, and so
1715 will be added to result first. This does not
1716 affect correctness, just "nicer". */
1717 for (int i = v->children.size () - 1; i >= 0; --i)
1719 varobj *c = v->children[i];
1721 /* Child may be NULL if explicitly deleted by -var-delete. */
1722 if (c != NULL && !c->frozen)
1723 stack.emplace_back (c);
1726 if (r.changed || r.type_changed)
1727 result.push_back (std::move (r));
1733 /* Helper functions */
1736 * Variable object construction/destruction
1740 delete_variable (struct varobj *var, bool only_children_p)
1744 delete_variable_1 (&delcount, var, only_children_p,
1745 true /* remove_from_parent_p */ );
1750 /* Delete the variable object VAR and its children. */
1751 /* IMPORTANT NOTE: If we delete a variable which is a child
1752 and the parent is not removed we dump core. It must be always
1753 initially called with remove_from_parent_p set. */
1755 delete_variable_1 (int *delcountp, struct varobj *var, bool only_children_p,
1756 bool remove_from_parent_p)
1758 /* Delete any children of this variable, too. */
1759 for (varobj *child : var->children)
1764 if (!remove_from_parent_p)
1765 child->parent = NULL;
1767 delete_variable_1 (delcountp, child, false, only_children_p);
1769 var->children.clear ();
1771 /* if we were called to delete only the children we are done here. */
1772 if (only_children_p)
1775 /* Otherwise, add it to the list of deleted ones and proceed to do so. */
1776 /* If the name is empty, this is a temporary variable, that has not
1777 yet been installed, don't report it, it belongs to the caller... */
1778 if (!var->obj_name.empty ())
1780 *delcountp = *delcountp + 1;
1783 /* If this variable has a parent, remove it from its parent's list. */
1784 /* OPTIMIZATION: if the parent of this variable is also being deleted,
1785 (as indicated by remove_from_parent_p) we don't bother doing an
1786 expensive list search to find the element to remove when we are
1787 discarding the list afterwards. */
1788 if ((remove_from_parent_p) && (var->parent != NULL))
1789 var->parent->children[var->index] = NULL;
1791 if (!var->obj_name.empty ())
1792 uninstall_variable (var);
1794 /* Free memory associated with this variable. */
1798 /* Install the given variable VAR with the object name VAR->OBJ_NAME. */
1800 install_variable (struct varobj *var)
1803 struct vlist *newvl;
1805 unsigned int index = 0;
1808 for (chp = var->obj_name.c_str (); *chp; chp++)
1810 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1813 cv = *(varobj_table + index);
1814 while (cv != NULL && cv->var->obj_name != var->obj_name)
1818 error (_("Duplicate variable object name"));
1820 /* Add varobj to hash table. */
1821 newvl = XNEW (struct vlist);
1822 newvl->next = *(varobj_table + index);
1824 *(varobj_table + index) = newvl;
1826 /* If root, add varobj to root list. */
1827 if (is_root_p (var))
1829 /* Add to list of root variables. */
1830 if (rootlist == NULL)
1831 var->root->next = NULL;
1833 var->root->next = rootlist;
1834 rootlist = var->root;
1837 return true; /* OK */
1840 /* Unistall the object VAR. */
1842 uninstall_variable (struct varobj *var)
1846 struct varobj_root *cr;
1847 struct varobj_root *prer;
1849 unsigned int index = 0;
1852 /* Remove varobj from hash table. */
1853 for (chp = var->obj_name.c_str (); *chp; chp++)
1855 index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
1858 cv = *(varobj_table + index);
1860 while (cv != NULL && cv->var->obj_name != var->obj_name)
1867 fprintf_unfiltered (gdb_stdlog, "Deleting %s\n", var->obj_name.c_str ());
1872 ("Assertion failed: Could not find variable object \"%s\" to delete",
1873 var->obj_name.c_str ());
1878 *(varobj_table + index) = cv->next;
1880 prev->next = cv->next;
1884 /* If root, remove varobj from root list. */
1885 if (is_root_p (var))
1887 /* Remove from list of root variables. */
1888 if (rootlist == var->root)
1889 rootlist = var->root->next;
1894 while ((cr != NULL) && (cr->rootvar != var))
1901 warning (_("Assertion failed: Could not find "
1902 "varobj \"%s\" in root list"),
1903 var->obj_name.c_str ());
1909 prer->next = cr->next;
1915 /* Create and install a child of the parent of the given name.
1917 The created VAROBJ takes ownership of the allocated NAME. */
1919 static struct varobj *
1920 create_child (struct varobj *parent, int index, std::string &name)
1922 struct varobj_item item;
1924 std::swap (item.name, name);
1925 item.value = value_of_child (parent, index);
1927 return create_child_with_value (parent, index, &item);
1930 static struct varobj *
1931 create_child_with_value (struct varobj *parent, int index,
1932 struct varobj_item *item)
1934 varobj *child = new varobj (parent->root);
1936 /* NAME is allocated by caller. */
1937 std::swap (child->name, item->name);
1938 child->index = index;
1939 child->parent = parent;
1941 if (varobj_is_anonymous_child (child))
1942 child->obj_name = string_printf ("%s.%d_anonymous",
1943 parent->obj_name.c_str (), index);
1945 child->obj_name = string_printf ("%s.%s",
1946 parent->obj_name.c_str (),
1947 child->name.c_str ());
1949 install_variable (child);
1951 /* Compute the type of the child. Must do this before
1952 calling install_new_value. */
1953 if (item->value != NULL)
1954 /* If the child had no evaluation errors, var->value
1955 will be non-NULL and contain a valid type. */
1956 child->type = value_actual_type (item->value, 0, NULL);
1958 /* Otherwise, we must compute the type. */
1959 child->type = (*child->root->lang_ops->type_of_child) (child->parent,
1961 install_new_value (child, item->value, 1);
1968 * Miscellaneous utility functions.
1971 /* Allocate memory and initialize a new variable. */
1972 varobj::varobj (varobj_root *root_)
1973 : root (root_), dynamic (new varobj_dynamic)
1977 /* Free any allocated memory associated with VAR. */
1984 if (var->dynamic->pretty_printer != NULL)
1986 gdbpy_enter_varobj enter_py (var);
1988 Py_XDECREF (var->dynamic->constructor);
1989 Py_XDECREF (var->dynamic->pretty_printer);
1993 varobj_iter_delete (var->dynamic->child_iter);
1994 varobj_clear_saved_item (var->dynamic);
1996 if (is_root_p (var))
1999 delete var->dynamic;
2002 /* Return the type of the value that's stored in VAR,
2003 or that would have being stored there if the
2004 value were accessible.
2006 This differs from VAR->type in that VAR->type is always
2007 the true type of the expession in the source language.
2008 The return value of this function is the type we're
2009 actually storing in varobj, and using for displaying
2010 the values and for comparing previous and new values.
2012 For example, top-level references are always stripped. */
2014 varobj_get_value_type (const struct varobj *var)
2018 if (var->value != nullptr)
2019 type = value_type (var->value.get ());
2023 type = check_typedef (type);
2025 if (TYPE_IS_REFERENCE (type))
2026 type = get_target_type (type);
2028 type = check_typedef (type);
2033 /* What is the default display for this variable? We assume that
2034 everything is "natural". Any exceptions? */
2035 static enum varobj_display_formats
2036 variable_default_display (struct varobj *var)
2038 return FORMAT_NATURAL;
2042 * Language-dependencies
2045 /* Common entry points */
2047 /* Return the number of children for a given variable.
2048 The result of this function is defined by the language
2049 implementation. The number of children returned by this function
2050 is the number of children that the user will see in the variable
2053 number_of_children (const struct varobj *var)
2055 return (*var->root->lang_ops->number_of_children) (var);
2058 /* What is the expression for the root varobj VAR? */
2061 name_of_variable (const struct varobj *var)
2063 return (*var->root->lang_ops->name_of_variable) (var);
2066 /* What is the name of the INDEX'th child of VAR? */
2069 name_of_child (struct varobj *var, int index)
2071 return (*var->root->lang_ops->name_of_child) (var, index);
2074 /* If frame associated with VAR can be found, switch
2075 to it and return true. Otherwise, return false. */
2078 check_scope (const struct varobj *var)
2080 struct frame_info *fi;
2083 fi = frame_find_by_id (var->root->frame);
2088 CORE_ADDR pc = get_frame_pc (fi);
2090 if (pc < BLOCK_START (var->root->valid_block) ||
2091 pc >= BLOCK_END (var->root->valid_block))
2099 /* Helper function to value_of_root. */
2101 static struct value *
2102 value_of_root_1 (struct varobj **var_handle)
2104 struct value *new_val = NULL;
2105 struct varobj *var = *var_handle;
2106 bool within_scope = false;
2108 /* Only root variables can be updated... */
2109 if (!is_root_p (var))
2110 /* Not a root var. */
2113 scoped_restore_current_thread restore_thread;
2115 /* Determine whether the variable is still around. */
2116 if (var->root->valid_block == NULL || var->root->floating)
2117 within_scope = true;
2118 else if (var->root->thread_id == 0)
2120 /* The program was single-threaded when the variable object was
2121 created. Technically, it's possible that the program became
2122 multi-threaded since then, but we don't support such
2124 within_scope = check_scope (var);
2128 thread_info *thread = find_thread_global_id (var->root->thread_id);
2132 switch_to_thread (thread);
2133 within_scope = check_scope (var);
2140 /* We need to catch errors here, because if evaluate
2141 expression fails we want to just return NULL. */
2144 new_val = evaluate_expression (var->root->exp.get ());
2146 CATCH (except, RETURN_MASK_ERROR)
2155 /* What is the ``struct value *'' of the root variable VAR?
2156 For floating variable object, evaluation can get us a value
2157 of different type from what is stored in varobj already. In
2159 - *type_changed will be set to 1
2160 - old varobj will be freed, and new one will be
2161 created, with the same name.
2162 - *var_handle will be set to the new varobj
2163 Otherwise, *type_changed will be set to 0. */
2164 static struct value *
2165 value_of_root (struct varobj **var_handle, bool *type_changed)
2169 if (var_handle == NULL)
2174 /* This should really be an exception, since this should
2175 only get called with a root variable. */
2177 if (!is_root_p (var))
2180 if (var->root->floating)
2182 struct varobj *tmp_var;
2184 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2185 USE_SELECTED_FRAME);
2186 if (tmp_var == NULL)
2190 std::string old_type = varobj_get_type (var);
2191 std::string new_type = varobj_get_type (tmp_var);
2192 if (old_type == new_type)
2194 /* The expression presently stored inside var->root->exp
2195 remembers the locations of local variables relatively to
2196 the frame where the expression was created (in DWARF location
2197 button, for example). Naturally, those locations are not
2198 correct in other frames, so update the expression. */
2200 std::swap (var->root->exp, tmp_var->root->exp);
2202 varobj_delete (tmp_var, 0);
2207 tmp_var->obj_name = var->obj_name;
2208 tmp_var->from = var->from;
2209 tmp_var->to = var->to;
2210 varobj_delete (var, 0);
2212 install_variable (tmp_var);
2213 *var_handle = tmp_var;
2215 *type_changed = true;
2224 struct value *value;
2226 value = value_of_root_1 (var_handle);
2227 if (var->value == NULL || value == NULL)
2229 /* For root varobj-s, a NULL value indicates a scoping issue.
2230 So, nothing to do in terms of checking for mutations. */
2232 else if (varobj_value_has_mutated (var, value, value_type (value)))
2234 /* The type has mutated, so the children are no longer valid.
2235 Just delete them, and tell our caller that the type has
2237 varobj_delete (var, 1 /* only_children */);
2238 var->num_children = -1;
2241 *type_changed = true;
2247 /* What is the ``struct value *'' for the INDEX'th child of PARENT? */
2248 static struct value *
2249 value_of_child (const struct varobj *parent, int index)
2251 struct value *value;
2253 value = (*parent->root->lang_ops->value_of_child) (parent, index);
2258 /* GDB already has a command called "value_of_variable". Sigh. */
2260 my_value_of_variable (struct varobj *var, enum varobj_display_formats format)
2262 if (var->root->is_valid)
2264 if (var->dynamic->pretty_printer != NULL)
2265 return varobj_value_get_print_value (var->value.get (), var->format,
2267 return (*var->root->lang_ops->value_of_variable) (var, format);
2270 return std::string ();
2274 varobj_formatted_print_options (struct value_print_options *opts,
2275 enum varobj_display_formats format)
2277 get_formatted_print_options (opts, format_code[(int) format]);
2278 opts->deref_ref = 0;
2279 opts->raw = !pretty_printing;
2283 varobj_value_get_print_value (struct value *value,
2284 enum varobj_display_formats format,
2285 const struct varobj *var)
2287 struct value_print_options opts;
2288 struct type *type = NULL;
2290 gdb::unique_xmalloc_ptr<char> encoding;
2291 /* Initialize it just to avoid a GCC false warning. */
2292 CORE_ADDR str_addr = 0;
2293 bool string_print = false;
2296 return std::string ();
2299 std::string thevalue;
2302 if (gdb_python_initialized)
2304 PyObject *value_formatter = var->dynamic->pretty_printer;
2306 gdbpy_enter_varobj enter_py (var);
2308 if (value_formatter)
2310 /* First check to see if we have any children at all. If so,
2311 we simply return {...}. */
2312 if (dynamic_varobj_has_child_method (var))
2315 if (PyObject_HasAttr (value_formatter, gdbpy_to_string_cst))
2317 struct value *replacement;
2319 gdbpy_ref<> output = apply_varobj_pretty_printer (value_formatter,
2323 /* If we have string like output ... */
2326 /* If this is a lazy string, extract it. For lazy
2327 strings we always print as a string, so set
2329 if (gdbpy_is_lazy_string (output.get ()))
2331 gdbpy_extract_lazy_string (output.get (), &str_addr,
2332 &type, &len, &encoding);
2333 string_print = true;
2337 /* If it is a regular (non-lazy) string, extract
2338 it and copy the contents into THEVALUE. If the
2339 hint says to print it as a string, set
2340 string_print. Otherwise just return the extracted
2341 string as a value. */
2343 gdb::unique_xmalloc_ptr<char> s
2344 = python_string_to_target_string (output.get ());
2348 struct gdbarch *gdbarch;
2350 gdb::unique_xmalloc_ptr<char> hint
2351 = gdbpy_get_display_hint (value_formatter);
2354 if (!strcmp (hint.get (), "string"))
2355 string_print = true;
2358 thevalue = std::string (s.get ());
2359 len = thevalue.size ();
2360 gdbarch = get_type_arch (value_type (value));
2361 type = builtin_type (gdbarch)->builtin_char;
2367 gdbpy_print_stack ();
2370 /* If the printer returned a replacement value, set VALUE
2371 to REPLACEMENT. If there is not a replacement value,
2372 just use the value passed to this function. */
2374 value = replacement;
2380 varobj_formatted_print_options (&opts, format);
2382 /* If the THEVALUE has contents, it is a regular string. */
2383 if (!thevalue.empty ())
2384 LA_PRINT_STRING (&stb, type, (gdb_byte *) thevalue.c_str (),
2385 len, encoding.get (), 0, &opts);
2386 else if (string_print)
2387 /* Otherwise, if string_print is set, and it is not a regular
2388 string, it is a lazy string. */
2389 val_print_string (type, encoding.get (), str_addr, len, &stb, &opts);
2391 /* All other cases. */
2392 common_val_print (value, &stb, 0, &opts, current_language);
2394 return std::move (stb.string ());
2398 varobj_editable_p (const struct varobj *var)
2402 if (!(var->root->is_valid && var->value != nullptr
2403 && VALUE_LVAL (var->value.get ())))
2406 type = varobj_get_value_type (var);
2408 switch (TYPE_CODE (type))
2410 case TYPE_CODE_STRUCT:
2411 case TYPE_CODE_UNION:
2412 case TYPE_CODE_ARRAY:
2413 case TYPE_CODE_FUNC:
2414 case TYPE_CODE_METHOD:
2424 /* Call VAR's value_is_changeable_p language-specific callback. */
2427 varobj_value_is_changeable_p (const struct varobj *var)
2429 return var->root->lang_ops->value_is_changeable_p (var);
2432 /* Return true if that varobj is floating, that is is always evaluated in the
2433 selected frame, and not bound to thread/frame. Such variable objects
2434 are created using '@' as frame specifier to -var-create. */
2436 varobj_floating_p (const struct varobj *var)
2438 return var->root->floating;
2441 /* Implement the "value_is_changeable_p" varobj callback for most
2445 varobj_default_value_is_changeable_p (const struct varobj *var)
2450 if (CPLUS_FAKE_CHILD (var))
2453 type = varobj_get_value_type (var);
2455 switch (TYPE_CODE (type))
2457 case TYPE_CODE_STRUCT:
2458 case TYPE_CODE_UNION:
2459 case TYPE_CODE_ARRAY:
2470 /* Iterate all the existing _root_ VAROBJs and call the FUNC callback for them
2471 with an arbitrary caller supplied DATA pointer. */
2474 all_root_varobjs (void (*func) (struct varobj *var, void *data), void *data)
2476 struct varobj_root *var_root, *var_root_next;
2478 /* Iterate "safely" - handle if the callee deletes its passed VAROBJ. */
2480 for (var_root = rootlist; var_root != NULL; var_root = var_root_next)
2482 var_root_next = var_root->next;
2484 (*func) (var_root->rootvar, data);
2488 /* Invalidate varobj VAR if it is tied to locals and re-create it if it is
2489 defined on globals. It is a helper for varobj_invalidate.
2491 This function is called after changing the symbol file, in this case the
2492 pointers to "struct type" stored by the varobj are no longer valid. All
2493 varobj must be either re-evaluated, or marked as invalid here. */
2496 varobj_invalidate_iter (struct varobj *var, void *unused)
2498 /* global and floating var must be re-evaluated. */
2499 if (var->root->floating || var->root->valid_block == NULL)
2501 struct varobj *tmp_var;
2503 /* Try to create a varobj with same expression. If we succeed
2504 replace the old varobj, otherwise invalidate it. */
2505 tmp_var = varobj_create (NULL, var->name.c_str (), (CORE_ADDR) 0,
2507 if (tmp_var != NULL)
2509 tmp_var->obj_name = var->obj_name;
2510 varobj_delete (var, 0);
2511 install_variable (tmp_var);
2514 var->root->is_valid = false;
2516 else /* locals must be invalidated. */
2517 var->root->is_valid = false;
2520 /* Invalidate the varobjs that are tied to locals and re-create the ones that
2521 are defined on globals.
2522 Invalidated varobjs will be always printed in_scope="invalid". */
2525 varobj_invalidate (void)
2527 all_root_varobjs (varobj_invalidate_iter, NULL);
2531 _initialize_varobj (void)
2533 varobj_table = XCNEWVEC (struct vlist *, VAROBJ_TABLE_SIZE);
2535 add_setshow_zuinteger_cmd ("varobj", class_maintenance,
2537 _("Set varobj debugging."),
2538 _("Show varobj debugging."),
2539 _("When non-zero, varobj debugging is enabled."),
2540 NULL, show_varobjdebug,
2541 &setdebuglist, &showdebuglist);