1 /* Implementation of the GDB variable objects API.
3 Copyright (C) 1999-2022 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"
29 #include "gdbthread.h"
31 #include "varobj-iter.h"
32 #include "parser-defs.h"
37 #include "python/python.h"
38 #include "python/python-internal.h"
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
;
106 /* Dynamic part of varobj. */
108 struct varobj_dynamic
110 /* Whether the children of this varobj were requested. This field is
111 used to decide if dynamic varobj should recompute their children.
112 In the event that the frontend never asked for the children, we
114 bool children_requested
= false;
116 /* The pretty-printer constructor. If NULL, then the default
117 pretty-printer will be looked up. If None, then no
118 pretty-printer will be installed. */
119 PyObject
*constructor
= NULL
;
121 /* The pretty-printer that has been constructed. If NULL, then a
122 new printer object is needed, and one will be constructed. */
123 PyObject
*pretty_printer
= NULL
;
125 /* The iterator returned by the printer's 'children' method, or NULL
127 std::unique_ptr
<varobj_iter
> child_iter
;
129 /* We request one extra item from the iterator, so that we can
130 report to the caller whether there are more items than we have
131 already reported. However, we don't want to install this value
132 when we read it, because that will mess up future updates. So,
133 we stash it here instead. */
134 std::unique_ptr
<varobj_item
> saved_item
;
137 /* Private function prototypes */
139 /* Helper functions for the above subcommands. */
141 static int delete_variable (struct varobj
*, bool);
143 static void delete_variable_1 (int *, struct varobj
*, bool, bool);
145 static void install_variable (struct varobj
*);
147 static void uninstall_variable (struct varobj
*);
149 static struct varobj
*create_child (struct varobj
*, int, std::string
&);
151 static struct varobj
*
152 create_child_with_value (struct varobj
*parent
, int index
,
153 struct varobj_item
*item
);
155 /* Utility routines */
157 static enum varobj_display_formats
variable_default_display (struct varobj
*);
159 static bool update_type_if_necessary (struct varobj
*var
,
160 struct value
*new_value
);
162 static bool install_new_value (struct varobj
*var
, struct value
*value
,
165 /* Language-specific routines. */
167 static int number_of_children (const struct varobj
*);
169 static std::string
name_of_variable (const struct varobj
*);
171 static std::string
name_of_child (struct varobj
*, int);
173 static struct value
*value_of_root (struct varobj
**var_handle
, bool *);
175 static struct value
*value_of_child (const struct varobj
*parent
, int index
);
177 static std::string
my_value_of_variable (struct varobj
*var
,
178 enum varobj_display_formats format
);
180 static bool is_root_p (const struct varobj
*var
);
182 static struct varobj
*varobj_add_child (struct varobj
*var
,
183 struct varobj_item
*item
);
187 /* Mappings of varobj_display_formats enums to gdb's format codes. */
188 static int format_code
[] = { 0, 't', 'd', 'x', 'o', 'z' };
190 /* List of root variable objects. */
191 static std::list
<struct varobj_root
*> rootlist
;
193 /* Pointer to the varobj hash table (built at run time). */
194 static htab_t varobj_table
;
198 /* API Implementation */
200 is_root_p (const struct varobj
*var
)
202 return (var
->root
->rootvar
== var
);
207 /* See python-internal.h. */
208 gdbpy_enter_varobj::gdbpy_enter_varobj (const struct varobj
*var
)
209 : gdbpy_enter (var
->root
->exp
->gdbarch
, var
->root
->exp
->language_defn
)
215 /* Return the full FRAME which corresponds to the given CORE_ADDR
216 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
218 static struct frame_info
*
219 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr
)
221 struct frame_info
*frame
= NULL
;
223 if (frame_addr
== (CORE_ADDR
) 0)
226 for (frame
= get_current_frame ();
228 frame
= get_prev_frame (frame
))
230 /* The CORE_ADDR we get as argument was parsed from a string GDB
231 output as $fp. This output got truncated to gdbarch_addr_bit.
232 Truncate the frame base address in the same manner before
233 comparing it against our argument. */
234 CORE_ADDR frame_base
= get_frame_base_address (frame
);
235 int addr_bit
= gdbarch_addr_bit (get_frame_arch (frame
));
237 if (addr_bit
< (sizeof (CORE_ADDR
) * HOST_CHAR_BIT
))
238 frame_base
&= ((CORE_ADDR
) 1 << addr_bit
) - 1;
240 if (frame_base
== frame_addr
)
247 /* Creates a varobj (not its children). */
250 varobj_create (const char *objname
,
251 const char *expression
, CORE_ADDR frame
, enum varobj_type type
)
253 /* Fill out a varobj structure for the (root) variable being constructed. */
254 std::unique_ptr
<varobj
> var (new varobj (new varobj_root
));
256 if (expression
!= NULL
)
258 struct frame_info
*fi
;
259 struct frame_id old_id
= null_frame_id
;
260 const struct block
*block
;
262 struct value
*value
= NULL
;
265 /* Parse and evaluate the expression, filling in as much of the
266 variable's data as possible. */
268 if (has_stack_frames ())
270 /* Allow creator to specify context of variable. */
271 if ((type
== USE_CURRENT_FRAME
) || (type
== USE_SELECTED_FRAME
))
272 fi
= get_selected_frame (NULL
);
274 /* FIXME: cagney/2002-11-23: This code should be doing a
275 lookup using the frame ID and not just the frame's
276 ``address''. This, of course, means an interface
277 change. However, with out that interface change ISAs,
278 such as the ia64 with its two stacks, won't work.
279 Similar goes for the case where there is a frameless
281 fi
= find_frame_addr_in_frame_chain (frame
);
286 if (type
== USE_SELECTED_FRAME
)
287 var
->root
->floating
= true;
293 block
= get_frame_block (fi
, 0);
294 pc
= get_frame_pc (fi
);
299 innermost_block_tracker
tracker (INNERMOST_BLOCK_FOR_SYMBOLS
300 | INNERMOST_BLOCK_FOR_REGISTERS
);
301 /* Wrap the call to parse expression, so we can
302 return a sensible error. */
305 var
->root
->exp
= parse_exp_1 (&p
, pc
, block
, 0, &tracker
);
308 catch (const gdb_exception_error
&except
)
313 /* Don't allow variables to be created for types. */
314 enum exp_opcode opcode
= var
->root
->exp
->first_opcode ();
315 if (opcode
== OP_TYPE
316 || opcode
== OP_TYPEOF
317 || opcode
== OP_DECLTYPE
)
319 fprintf_unfiltered (gdb_stderr
, "Attempt to use a type name"
320 " as an expression.\n");
324 var
->format
= variable_default_display (var
.get ());
325 var
->root
->valid_block
=
326 var
->root
->floating
? NULL
: tracker
.block ();
327 var
->name
= expression
;
328 /* For a root var, the name and the expr are the same. */
329 var
->path_expr
= expression
;
331 /* When the frame is different from the current frame,
332 we must select the appropriate frame before parsing
333 the expression, otherwise the value will not be current.
334 Since select_frame is so benign, just call it for all cases. */
335 if (var
->root
->valid_block
)
337 /* User could specify explicit FRAME-ADDR which was not found but
338 EXPRESSION is frame specific and we would not be able to evaluate
339 it correctly next time. With VALID_BLOCK set we must also set
340 FRAME and THREAD_ID. */
342 error (_("Failed to find the specified frame"));
344 var
->root
->frame
= get_frame_id (fi
);
345 var
->root
->thread_id
= inferior_thread ()->global_num
;
346 old_id
= get_frame_id (get_selected_frame (NULL
));
350 /* We definitely need to catch errors here.
351 If evaluate_expression succeeds we got the value we wanted.
352 But if it fails, we still go on with a call to evaluate_type(). */
355 value
= evaluate_expression (var
->root
->exp
.get ());
357 catch (const gdb_exception_error
&except
)
359 /* Error getting the value. Try to at least get the
361 struct value
*type_only_value
= evaluate_type (var
->root
->exp
.get ());
363 var
->type
= value_type (type_only_value
);
368 int real_type_found
= 0;
370 var
->type
= value_actual_type (value
, 0, &real_type_found
);
372 value
= value_cast (var
->type
, value
);
375 /* Set language info */
376 var
->root
->lang_ops
= var
->root
->exp
->language_defn
->varobj_ops ();
378 install_new_value (var
.get (), value
, 1 /* Initial assignment */);
380 /* Set ourselves as our root. */
381 var
->root
->rootvar
= var
.get ();
383 /* Reset the selected frame. */
384 if (frame_id_p (old_id
))
385 select_frame (frame_find_by_id (old_id
));
388 /* If the variable object name is null, that means this
389 is a temporary variable, so don't install it. */
391 if ((var
!= NULL
) && (objname
!= NULL
))
393 var
->obj_name
= objname
;
394 install_variable (var
.get ());
397 return var
.release ();
400 /* Generates an unique name that can be used for a varobj. */
403 varobj_gen_name (void)
407 /* Generate a name for this object. */
409 return string_printf ("var%d", id
);
412 /* Given an OBJNAME, returns the pointer to the corresponding varobj. Call
413 error if OBJNAME cannot be found. */
416 varobj_get_handle (const char *objname
)
418 varobj
*var
= (varobj
*) htab_find_with_hash (varobj_table
, objname
,
419 htab_hash_string (objname
));
422 error (_("Variable object not found"));
427 /* Given the handle, return the name of the object. */
430 varobj_get_objname (const struct varobj
*var
)
432 return var
->obj_name
.c_str ();
435 /* Given the handle, return the expression represented by the
439 varobj_get_expression (const struct varobj
*var
)
441 return name_of_variable (var
);
447 varobj_delete (struct varobj
*var
, bool only_children
)
449 return delete_variable (var
, only_children
);
454 /* Convenience function for varobj_set_visualizer. Instantiate a
455 pretty-printer for a given value. */
457 instantiate_pretty_printer (PyObject
*constructor
, struct value
*value
)
459 gdbpy_ref
<> val_obj (value_to_value_object (value
));
460 if (val_obj
== nullptr)
463 return PyObject_CallFunctionObjArgs (constructor
, val_obj
.get (), NULL
);
468 /* Set/Get variable object display format. */
470 enum varobj_display_formats
471 varobj_set_display_format (struct varobj
*var
,
472 enum varobj_display_formats format
)
479 case FORMAT_HEXADECIMAL
:
481 case FORMAT_ZHEXADECIMAL
:
482 var
->format
= format
;
486 var
->format
= variable_default_display (var
);
489 if (varobj_value_is_changeable_p (var
)
490 && var
->value
!= nullptr && !value_lazy (var
->value
.get ()))
492 var
->print_value
= varobj_value_get_print_value (var
->value
.get (),
499 enum varobj_display_formats
500 varobj_get_display_format (const struct varobj
*var
)
505 gdb::unique_xmalloc_ptr
<char>
506 varobj_get_display_hint (const struct varobj
*var
)
508 gdb::unique_xmalloc_ptr
<char> result
;
511 if (!gdb_python_initialized
)
514 gdbpy_enter_varobj
enter_py (var
);
516 if (var
->dynamic
->pretty_printer
!= NULL
)
517 result
= gdbpy_get_display_hint (var
->dynamic
->pretty_printer
);
523 /* Return true if the varobj has items after TO, false otherwise. */
526 varobj_has_more (const struct varobj
*var
, int to
)
528 if (var
->children
.size () > to
)
531 return ((to
== -1 || var
->children
.size () == to
)
532 && (var
->dynamic
->saved_item
!= NULL
));
535 /* If the variable object is bound to a specific thread, that
536 is its evaluation can always be done in context of a frame
537 inside that thread, returns GDB id of the thread -- which
538 is always positive. Otherwise, returns -1. */
540 varobj_get_thread_id (const struct varobj
*var
)
542 if (var
->root
->valid_block
&& var
->root
->thread_id
> 0)
543 return var
->root
->thread_id
;
549 varobj_set_frozen (struct varobj
*var
, bool frozen
)
551 /* When a variable is unfrozen, we don't fetch its value.
552 The 'not_fetched' flag remains set, so next -var-update
555 We don't fetch the value, because for structures the client
556 should do -var-update anyway. It would be bad to have different
557 client-size logic for structure and other types. */
558 var
->frozen
= frozen
;
562 varobj_get_frozen (const struct varobj
*var
)
567 /* A helper function that updates the contents of FROM and TO based on the
568 size of the vector CHILDREN. If the contents of either FROM or TO are
569 negative the entire range is used. */
572 varobj_restrict_range (const std::vector
<varobj
*> &children
,
575 int len
= children
.size ();
577 if (*from
< 0 || *to
< 0)
593 /* A helper for update_dynamic_varobj_children that installs a new
594 child when needed. */
597 install_dynamic_child (struct varobj
*var
,
598 std::vector
<varobj
*> *changed
,
599 std::vector
<varobj
*> *type_changed
,
600 std::vector
<varobj
*> *newobj
,
601 std::vector
<varobj
*> *unchanged
,
604 struct varobj_item
*item
)
606 if (var
->children
.size () < index
+ 1)
608 /* There's no child yet. */
609 struct varobj
*child
= varobj_add_child (var
, item
);
613 newobj
->push_back (child
);
619 varobj
*existing
= var
->children
[index
];
620 bool type_updated
= update_type_if_necessary (existing
,
625 if (type_changed
!= NULL
)
626 type_changed
->push_back (existing
);
628 if (install_new_value (existing
, item
->value
.get (), 0))
630 if (!type_updated
&& changed
!= NULL
)
631 changed
->push_back (existing
);
633 else if (!type_updated
&& unchanged
!= NULL
)
634 unchanged
->push_back (existing
);
641 dynamic_varobj_has_child_method (const struct varobj
*var
)
643 PyObject
*printer
= var
->dynamic
->pretty_printer
;
645 if (!gdb_python_initialized
)
648 gdbpy_enter_varobj
enter_py (var
);
649 return PyObject_HasAttr (printer
, gdbpy_children_cst
);
653 /* A factory for creating dynamic varobj's iterators. Returns an
654 iterator object suitable for iterating over VAR's children. */
656 static std::unique_ptr
<varobj_iter
>
657 varobj_get_iterator (struct varobj
*var
)
660 if (var
->dynamic
->pretty_printer
)
661 return py_varobj_get_iterator (var
, var
->dynamic
->pretty_printer
);
664 gdb_assert_not_reached ("requested an iterator from a non-dynamic varobj");
668 update_dynamic_varobj_children (struct varobj
*var
,
669 std::vector
<varobj
*> *changed
,
670 std::vector
<varobj
*> *type_changed
,
671 std::vector
<varobj
*> *newobj
,
672 std::vector
<varobj
*> *unchanged
,
674 bool update_children
,
682 if (update_children
|| var
->dynamic
->child_iter
== NULL
)
684 var
->dynamic
->child_iter
= varobj_get_iterator (var
);
685 var
->dynamic
->saved_item
.reset (nullptr);
689 if (var
->dynamic
->child_iter
== NULL
)
693 i
= var
->children
.size ();
695 /* We ask for one extra child, so that MI can report whether there
696 are more children. */
697 for (; to
< 0 || i
< to
+ 1; ++i
)
699 std::unique_ptr
<varobj_item
> item
;
701 /* See if there was a leftover from last time. */
702 if (var
->dynamic
->saved_item
!= NULL
)
703 item
= std::move (var
->dynamic
->saved_item
);
705 item
= var
->dynamic
->child_iter
->next ();
709 /* Iteration is done. Remove iterator from VAR. */
710 var
->dynamic
->child_iter
.reset (nullptr);
713 /* We don't want to push the extra child on any report list. */
714 if (to
< 0 || i
< to
)
716 bool can_mention
= from
< 0 || i
>= from
;
718 install_dynamic_child (var
, can_mention
? changed
: NULL
,
719 can_mention
? type_changed
: NULL
,
720 can_mention
? newobj
: NULL
,
721 can_mention
? unchanged
: NULL
,
722 can_mention
? cchanged
: NULL
, i
,
727 var
->dynamic
->saved_item
= std::move (item
);
729 /* We want to truncate the child list just before this
735 if (i
< var
->children
.size ())
738 for (int j
= i
; j
< var
->children
.size (); ++j
)
739 varobj_delete (var
->children
[j
], 0);
741 var
->children
.resize (i
);
744 /* If there are fewer children than requested, note that the list of
746 if (to
>= 0 && var
->children
.size () < to
)
749 var
->num_children
= var
->children
.size ();
755 varobj_get_num_children (struct varobj
*var
)
757 if (var
->num_children
== -1)
759 if (varobj_is_dynamic_p (var
))
763 /* If we have a dynamic varobj, don't report -1 children.
764 So, try to fetch some children first. */
765 update_dynamic_varobj_children (var
, NULL
, NULL
, NULL
, NULL
, &dummy
,
769 var
->num_children
= number_of_children (var
);
772 return var
->num_children
>= 0 ? var
->num_children
: 0;
775 /* Creates a list of the immediate children of a variable object;
776 the return code is the number of such children or -1 on error. */
778 const std::vector
<varobj
*> &
779 varobj_list_children (struct varobj
*var
, int *from
, int *to
)
781 var
->dynamic
->children_requested
= true;
783 if (varobj_is_dynamic_p (var
))
785 bool children_changed
;
787 /* This, in theory, can result in the number of children changing without
788 frontend noticing. But well, calling -var-list-children on the same
789 varobj twice is not something a sane frontend would do. */
790 update_dynamic_varobj_children (var
, NULL
, NULL
, NULL
, NULL
,
791 &children_changed
, false, 0, *to
);
792 varobj_restrict_range (var
->children
, from
, to
);
793 return var
->children
;
796 if (var
->num_children
== -1)
797 var
->num_children
= number_of_children (var
);
799 /* If that failed, give up. */
800 if (var
->num_children
== -1)
801 return var
->children
;
803 /* If we're called when the list of children is not yet initialized,
804 allocate enough elements in it. */
805 while (var
->children
.size () < var
->num_children
)
806 var
->children
.push_back (NULL
);
808 for (int i
= 0; i
< var
->num_children
; i
++)
810 if (var
->children
[i
] == NULL
)
812 /* Either it's the first call to varobj_list_children for
813 this variable object, and the child was never created,
814 or it was explicitly deleted by the client. */
815 std::string name
= name_of_child (var
, i
);
816 var
->children
[i
] = create_child (var
, i
, name
);
820 varobj_restrict_range (var
->children
, from
, to
);
821 return var
->children
;
824 static struct varobj
*
825 varobj_add_child (struct varobj
*var
, struct varobj_item
*item
)
827 varobj
*v
= create_child_with_value (var
, var
->children
.size (), item
);
829 var
->children
.push_back (v
);
834 /* Obtain the type of an object Variable as a string similar to the one gdb
835 prints on the console. The caller is responsible for freeing the string.
839 varobj_get_type (struct varobj
*var
)
841 /* For the "fake" variables, do not return a type. (Its type is
843 Do not return a type for invalid variables as well. */
844 if (CPLUS_FAKE_CHILD (var
) || !var
->root
->is_valid
)
845 return std::string ();
847 return type_to_string (var
->type
);
850 /* Obtain the type of an object variable. */
853 varobj_get_gdb_type (const struct varobj
*var
)
858 /* Is VAR a path expression parent, i.e., can it be used to construct
859 a valid path expression? */
862 is_path_expr_parent (const struct varobj
*var
)
864 gdb_assert (var
->root
->lang_ops
->is_path_expr_parent
!= NULL
);
865 return var
->root
->lang_ops
->is_path_expr_parent (var
);
868 /* Is VAR a path expression parent, i.e., can it be used to construct
869 a valid path expression? By default we assume any VAR can be a path
873 varobj_default_is_path_expr_parent (const struct varobj
*var
)
878 /* Return the path expression parent for VAR. */
880 const struct varobj
*
881 varobj_get_path_expr_parent (const struct varobj
*var
)
883 const struct varobj
*parent
= var
;
885 while (!is_root_p (parent
) && !is_path_expr_parent (parent
))
886 parent
= parent
->parent
;
888 /* Computation of full rooted expression for children of dynamic
889 varobjs is not supported. */
890 if (varobj_is_dynamic_p (parent
))
891 error (_("Invalid variable object (child of a dynamic varobj)"));
896 /* Return a pointer to the full rooted expression of varobj VAR.
897 If it has not been computed yet, compute it. */
900 varobj_get_path_expr (const struct varobj
*var
)
902 if (var
->path_expr
.empty ())
904 /* For root varobjs, we initialize path_expr
905 when creating varobj, so here it should be
907 struct varobj
*mutable_var
= (struct varobj
*) var
;
908 gdb_assert (!is_root_p (var
));
910 mutable_var
->path_expr
= (*var
->root
->lang_ops
->path_expr_of_child
) (var
);
913 return var
->path_expr
.c_str ();
916 const struct language_defn
*
917 varobj_get_language (const struct varobj
*var
)
919 return var
->root
->exp
->language_defn
;
923 varobj_get_attributes (const struct varobj
*var
)
927 if (varobj_editable_p (var
))
928 /* FIXME: define masks for attributes. */
929 attributes
|= 0x00000001; /* Editable */
934 /* Return true if VAR is a dynamic varobj. */
937 varobj_is_dynamic_p (const struct varobj
*var
)
939 return var
->dynamic
->pretty_printer
!= NULL
;
943 varobj_get_formatted_value (struct varobj
*var
,
944 enum varobj_display_formats format
)
946 return my_value_of_variable (var
, format
);
950 varobj_get_value (struct varobj
*var
)
952 return my_value_of_variable (var
, var
->format
);
955 /* Set the value of an object variable (if it is editable) to the
956 value of the given expression. */
957 /* Note: Invokes functions that can call error(). */
960 varobj_set_value (struct varobj
*var
, const char *expression
)
962 struct value
*val
= NULL
; /* Initialize to keep gcc happy. */
963 /* The argument "expression" contains the variable's new value.
964 We need to first construct a legal expression for this -- ugh! */
965 /* Does this cover all the bases? */
966 struct value
*value
= NULL
; /* Initialize to keep gcc happy. */
967 int saved_input_radix
= input_radix
;
968 const char *s
= expression
;
970 gdb_assert (varobj_editable_p (var
));
972 input_radix
= 10; /* ALWAYS reset to decimal temporarily. */
973 expression_up exp
= parse_exp_1 (&s
, 0, 0, 0);
976 value
= evaluate_expression (exp
.get ());
979 catch (const gdb_exception_error
&except
)
981 /* We cannot proceed without a valid expression. */
985 /* All types that are editable must also be changeable. */
986 gdb_assert (varobj_value_is_changeable_p (var
));
988 /* The value of a changeable variable object must not be lazy. */
989 gdb_assert (!value_lazy (var
->value
.get ()));
991 /* Need to coerce the input. We want to check if the
992 value of the variable object will be different
993 after assignment, and the first thing value_assign
994 does is coerce the input.
995 For example, if we are assigning an array to a pointer variable we
996 should compare the pointer with the array's address, not with the
998 value
= coerce_array (value
);
1000 /* The new value may be lazy. value_assign, or
1001 rather value_contents, will take care of this. */
1004 val
= value_assign (var
->value
.get (), value
);
1007 catch (const gdb_exception_error
&except
)
1012 /* If the value has changed, record it, so that next -var-update can
1013 report this change. If a variable had a value of '1', we've set it
1014 to '333' and then set again to '1', when -var-update will report this
1015 variable as changed -- because the first assignment has set the
1016 'updated' flag. There's no need to optimize that, because return value
1017 of -var-update should be considered an approximation. */
1018 var
->updated
= install_new_value (var
, val
, false /* Compare values. */);
1019 input_radix
= saved_input_radix
;
1025 /* A helper function to install a constructor function and visualizer
1026 in a varobj_dynamic. */
1029 install_visualizer (struct varobj_dynamic
*var
, PyObject
*constructor
,
1030 PyObject
*visualizer
)
1032 Py_XDECREF (var
->constructor
);
1033 var
->constructor
= constructor
;
1035 Py_XDECREF (var
->pretty_printer
);
1036 var
->pretty_printer
= visualizer
;
1038 var
->child_iter
.reset (nullptr);
1041 /* Install the default visualizer for VAR. */
1044 install_default_visualizer (struct varobj
*var
)
1046 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1047 if (CPLUS_FAKE_CHILD (var
))
1050 if (pretty_printing
)
1052 gdbpy_ref
<> pretty_printer
;
1054 if (var
->value
!= nullptr)
1056 pretty_printer
= gdbpy_get_varobj_pretty_printer (var
->value
.get ());
1057 if (pretty_printer
== nullptr)
1059 gdbpy_print_stack ();
1060 error (_("Cannot instantiate printer for default visualizer"));
1064 if (pretty_printer
== Py_None
)
1065 pretty_printer
.reset (nullptr);
1067 install_visualizer (var
->dynamic
, NULL
, pretty_printer
.release ());
1071 /* Instantiate and install a visualizer for VAR using CONSTRUCTOR to
1072 make a new object. */
1075 construct_visualizer (struct varobj
*var
, PyObject
*constructor
)
1077 PyObject
*pretty_printer
;
1079 /* Do not install a visualizer on a CPLUS_FAKE_CHILD. */
1080 if (CPLUS_FAKE_CHILD (var
))
1083 Py_INCREF (constructor
);
1084 if (constructor
== Py_None
)
1085 pretty_printer
= NULL
;
1088 pretty_printer
= instantiate_pretty_printer (constructor
,
1090 if (! pretty_printer
)
1092 gdbpy_print_stack ();
1093 Py_DECREF (constructor
);
1094 constructor
= Py_None
;
1095 Py_INCREF (constructor
);
1098 if (pretty_printer
== Py_None
)
1100 Py_DECREF (pretty_printer
);
1101 pretty_printer
= NULL
;
1105 install_visualizer (var
->dynamic
, constructor
, pretty_printer
);
1108 #endif /* HAVE_PYTHON */
1110 /* A helper function for install_new_value. This creates and installs
1111 a visualizer for VAR, if appropriate. */
1114 install_new_value_visualizer (struct varobj
*var
)
1117 /* If the constructor is None, then we want the raw value. If VAR
1118 does not have a value, just skip this. */
1119 if (!gdb_python_initialized
)
1122 if (var
->dynamic
->constructor
!= Py_None
&& var
->value
!= NULL
)
1124 gdbpy_enter_varobj
enter_py (var
);
1126 if (var
->dynamic
->constructor
== NULL
)
1127 install_default_visualizer (var
);
1129 construct_visualizer (var
, var
->dynamic
->constructor
);
1136 /* When using RTTI to determine variable type it may be changed in runtime when
1137 the variable value is changed. This function checks whether type of varobj
1138 VAR will change when a new value NEW_VALUE is assigned and if it is so
1139 updates the type of VAR. */
1142 update_type_if_necessary (struct varobj
*var
, struct value
*new_value
)
1146 struct value_print_options opts
;
1148 get_user_print_options (&opts
);
1149 if (opts
.objectprint
)
1151 struct type
*new_type
= value_actual_type (new_value
, 0, 0);
1152 std::string new_type_str
= type_to_string (new_type
);
1153 std::string curr_type_str
= varobj_get_type (var
);
1155 /* Did the type name change? */
1156 if (curr_type_str
!= new_type_str
)
1158 var
->type
= new_type
;
1160 /* This information may be not valid for a new type. */
1161 varobj_delete (var
, 1);
1162 var
->children
.clear ();
1163 var
->num_children
= -1;
1172 /* Assign a new value to a variable object. If INITIAL is true,
1173 this is the first assignment after the variable object was just
1174 created, or changed type. In that case, just assign the value
1176 Otherwise, assign the new value, and return true if the value is
1177 different from the current one, false otherwise. The comparison is
1178 done on textual representation of value. Therefore, some types
1179 need not be compared. E.g. for structures the reported value is
1180 always "{...}", so no comparison is necessary here. If the old
1181 value was NULL and new one is not, or vice versa, we always return true.
1183 The VALUE parameter should not be released -- the function will
1184 take care of releasing it when needed. */
1186 install_new_value (struct varobj
*var
, struct value
*value
, bool initial
)
1190 bool changed
= false;
1191 bool intentionally_not_fetched
= false;
1193 /* We need to know the varobj's type to decide if the value should
1194 be fetched or not. C++ fake children (public/protected/private)
1195 don't have a type. */
1196 gdb_assert (var
->type
|| CPLUS_FAKE_CHILD (var
));
1197 changeable
= varobj_value_is_changeable_p (var
);
1199 /* If the type has custom visualizer, we consider it to be always
1200 changeable. FIXME: need to make sure this behaviour will not
1201 mess up read-sensitive values. */
1202 if (var
->dynamic
->pretty_printer
!= NULL
)
1205 need_to_fetch
= changeable
;
1207 /* We are not interested in the address of references, and given
1208 that in C++ a reference is not rebindable, it cannot
1209 meaningfully change. So, get hold of the real value. */
1211 value
= coerce_ref (value
);
1213 if (var
->type
&& var
->type
->code () == TYPE_CODE_UNION
)
1214 /* For unions, we need to fetch the value implicitly because
1215 of implementation of union member fetch. When gdb
1216 creates a value for a field and the value of the enclosing
1217 structure is not lazy, it immediately copies the necessary
1218 bytes from the enclosing values. If the enclosing value is
1219 lazy, the call to value_fetch_lazy on the field will read
1220 the data from memory. For unions, that means we'll read the
1221 same memory more than once, which is not desirable. So
1223 need_to_fetch
= true;
1225 /* The new value might be lazy. If the type is changeable,
1226 that is we'll be comparing values of this type, fetch the
1227 value now. Otherwise, on the next update the old value
1228 will be lazy, which means we've lost that old value. */
1229 if (need_to_fetch
&& value
&& value_lazy (value
))
1231 const struct varobj
*parent
= var
->parent
;
1232 bool frozen
= var
->frozen
;
1234 for (; !frozen
&& parent
; parent
= parent
->parent
)
1235 frozen
|= parent
->frozen
;
1237 if (frozen
&& initial
)
1239 /* For variables that are frozen, or are children of frozen
1240 variables, we don't do fetch on initial assignment.
1241 For non-initial assignment we do the fetch, since it means we're
1242 explicitly asked to compare the new value with the old one. */
1243 intentionally_not_fetched
= true;
1250 value_fetch_lazy (value
);
1253 catch (const gdb_exception_error
&except
)
1255 /* Set the value to NULL, so that for the next -var-update,
1256 we don't try to compare the new value with this value,
1257 that we couldn't even read. */
1263 /* Get a reference now, before possibly passing it to any Python
1264 code that might release it. */
1265 value_ref_ptr value_holder
;
1267 value_holder
= value_ref_ptr::new_reference (value
);
1269 /* Below, we'll be comparing string rendering of old and new
1270 values. Don't get string rendering if the value is
1271 lazy -- if it is, the code above has decided that the value
1272 should not be fetched. */
1273 std::string print_value
;
1274 if (value
!= NULL
&& !value_lazy (value
)
1275 && var
->dynamic
->pretty_printer
== NULL
)
1276 print_value
= varobj_value_get_print_value (value
, var
->format
, var
);
1278 /* If the type is changeable, compare the old and the new values.
1279 If this is the initial assignment, we don't have any old value
1281 if (!initial
&& changeable
)
1283 /* If the value of the varobj was changed by -var-set-value,
1284 then the value in the varobj and in the target is the same.
1285 However, that value is different from the value that the
1286 varobj had after the previous -var-update. So need to the
1287 varobj as changed. */
1290 else if (var
->dynamic
->pretty_printer
== NULL
)
1292 /* Try to compare the values. That requires that both
1293 values are non-lazy. */
1294 if (var
->not_fetched
&& value_lazy (var
->value
.get ()))
1296 /* This is a frozen varobj and the value was never read.
1297 Presumably, UI shows some "never read" indicator.
1298 Now that we've fetched the real value, we need to report
1299 this varobj as changed so that UI can show the real
1303 else if (var
->value
== NULL
&& value
== NULL
)
1306 else if (var
->value
== NULL
|| value
== NULL
)
1312 gdb_assert (!value_lazy (var
->value
.get ()));
1313 gdb_assert (!value_lazy (value
));
1315 gdb_assert (!var
->print_value
.empty () && !print_value
.empty ());
1316 if (var
->print_value
!= print_value
)
1322 if (!initial
&& !changeable
)
1324 /* For values that are not changeable, we don't compare the values.
1325 However, we want to notice if a value was not NULL and now is NULL,
1326 or vise versa, so that we report when top-level varobjs come in scope
1327 and leave the scope. */
1328 changed
= (var
->value
!= NULL
) != (value
!= NULL
);
1331 /* We must always keep the new value, since children depend on it. */
1332 var
->value
= value_holder
;
1333 if (value
&& value_lazy (value
) && intentionally_not_fetched
)
1334 var
->not_fetched
= true;
1336 var
->not_fetched
= false;
1337 var
->updated
= false;
1339 install_new_value_visualizer (var
);
1341 /* If we installed a pretty-printer, re-compare the printed version
1342 to see if the variable changed. */
1343 if (var
->dynamic
->pretty_printer
!= NULL
)
1345 print_value
= varobj_value_get_print_value (var
->value
.get (),
1347 if ((var
->print_value
.empty () && !print_value
.empty ())
1348 || (!var
->print_value
.empty () && print_value
.empty ())
1349 || (!var
->print_value
.empty () && !print_value
.empty ()
1350 && var
->print_value
!= print_value
))
1353 var
->print_value
= print_value
;
1355 gdb_assert (var
->value
== nullptr || value_type (var
->value
.get ()));
1360 /* Return the requested range for a varobj. VAR is the varobj. FROM
1361 and TO are out parameters; *FROM and *TO will be set to the
1362 selected sub-range of VAR. If no range was selected using
1363 -var-set-update-range, then both will be -1. */
1365 varobj_get_child_range (const struct varobj
*var
, int *from
, int *to
)
1371 /* Set the selected sub-range of children of VAR to start at index
1372 FROM and end at index TO. If either FROM or TO is less than zero,
1373 this is interpreted as a request for all children. */
1375 varobj_set_child_range (struct varobj
*var
, int from
, int to
)
1382 varobj_set_visualizer (struct varobj
*var
, const char *visualizer
)
1387 if (!gdb_python_initialized
)
1390 gdbpy_enter_varobj
enter_py (var
);
1392 mainmod
= PyImport_AddModule ("__main__");
1394 = gdbpy_ref
<>::new_reference (PyModule_GetDict (mainmod
));
1395 gdbpy_ref
<> constructor (PyRun_String (visualizer
, Py_eval_input
,
1396 globals
.get (), globals
.get ()));
1398 if (constructor
== NULL
)
1400 gdbpy_print_stack ();
1401 error (_("Could not evaluate visualizer expression: %s"), visualizer
);
1404 construct_visualizer (var
, constructor
.get ());
1406 /* If there are any children now, wipe them. */
1407 varobj_delete (var
, 1 /* children only */);
1408 var
->num_children
= -1;
1410 error (_("Python support required"));
1414 /* If NEW_VALUE is the new value of the given varobj (var), return
1415 true if var has mutated. In other words, if the type of
1416 the new value is different from the type of the varobj's old
1419 NEW_VALUE may be NULL, if the varobj is now out of scope. */
1422 varobj_value_has_mutated (const struct varobj
*var
, struct value
*new_value
,
1423 struct type
*new_type
)
1425 /* If we haven't previously computed the number of children in var,
1426 it does not matter from the front-end's perspective whether
1427 the type has mutated or not. For all intents and purposes,
1428 it has not mutated. */
1429 if (var
->num_children
< 0)
1432 if (var
->root
->lang_ops
->value_has_mutated
!= NULL
)
1434 /* The varobj module, when installing new values, explicitly strips
1435 references, saying that we're not interested in those addresses.
1436 But detection of mutation happens before installing the new
1437 value, so our value may be a reference that we need to strip
1438 in order to remain consistent. */
1439 if (new_value
!= NULL
)
1440 new_value
= coerce_ref (new_value
);
1441 return var
->root
->lang_ops
->value_has_mutated (var
, new_value
, new_type
);
1447 /* Update the values for a variable and its children. This is a
1448 two-pronged attack. First, re-parse the value for the root's
1449 expression to see if it's changed. Then go all the way
1450 through its children, reconstructing them and noting if they've
1453 The IS_EXPLICIT parameter specifies if this call is result
1454 of MI request to update this specific variable, or
1455 result of implicit -var-update *. For implicit request, we don't
1456 update frozen variables.
1458 NOTE: This function may delete the caller's varobj. If it
1459 returns TYPE_CHANGED, then it has done this and VARP will be modified
1460 to point to the new varobj. */
1462 std::vector
<varobj_update_result
>
1463 varobj_update (struct varobj
**varp
, bool is_explicit
)
1465 bool type_changed
= false;
1466 struct value
*newobj
;
1467 std::vector
<varobj_update_result
> stack
;
1468 std::vector
<varobj_update_result
> result
;
1470 /* Frozen means frozen -- we don't check for any change in
1471 this varobj, including its going out of scope, or
1472 changing type. One use case for frozen varobjs is
1473 retaining previously evaluated expressions, and we don't
1474 want them to be reevaluated at all. */
1475 if (!is_explicit
&& (*varp
)->frozen
)
1478 if (!(*varp
)->root
->is_valid
)
1480 result
.emplace_back (*varp
, VAROBJ_INVALID
);
1484 if ((*varp
)->root
->rootvar
== *varp
)
1486 varobj_update_result
r (*varp
);
1488 /* Update the root variable. value_of_root can return NULL
1489 if the variable is no longer around, i.e. we stepped out of
1490 the frame in which a local existed. We are letting the
1491 value_of_root variable dispose of the varobj if the type
1493 newobj
= value_of_root (varp
, &type_changed
);
1494 if (update_type_if_necessary (*varp
, newobj
))
1495 type_changed
= true;
1497 r
.type_changed
= type_changed
;
1498 if (install_new_value ((*varp
), newobj
, type_changed
))
1502 r
.status
= VAROBJ_NOT_IN_SCOPE
;
1503 r
.value_installed
= true;
1505 if (r
.status
== VAROBJ_NOT_IN_SCOPE
)
1507 if (r
.type_changed
|| r
.changed
)
1508 result
.push_back (std::move (r
));
1513 stack
.push_back (std::move (r
));
1516 stack
.emplace_back (*varp
);
1518 /* Walk through the children, reconstructing them all. */
1519 while (!stack
.empty ())
1521 varobj_update_result r
= std::move (stack
.back ());
1523 struct varobj
*v
= r
.varobj
;
1525 /* Update this variable, unless it's a root, which is already
1527 if (!r
.value_installed
)
1529 struct type
*new_type
;
1531 newobj
= value_of_child (v
->parent
, v
->index
);
1532 if (update_type_if_necessary (v
, newobj
))
1533 r
.type_changed
= true;
1535 new_type
= value_type (newobj
);
1537 new_type
= v
->root
->lang_ops
->type_of_child (v
->parent
, v
->index
);
1539 if (varobj_value_has_mutated (v
, newobj
, new_type
))
1541 /* The children are no longer valid; delete them now.
1542 Report the fact that its type changed as well. */
1543 varobj_delete (v
, 1 /* only_children */);
1544 v
->num_children
= -1;
1548 r
.type_changed
= true;
1551 if (install_new_value (v
, newobj
, r
.type_changed
))
1558 /* We probably should not get children of a dynamic varobj, but
1559 for which -var-list-children was never invoked. */
1560 if (varobj_is_dynamic_p (v
))
1562 std::vector
<varobj
*> changed
, type_changed_vec
, unchanged
, newobj_vec
;
1563 bool children_changed
= false;
1568 if (!v
->dynamic
->children_requested
)
1572 /* If we initially did not have potential children, but
1573 now we do, consider the varobj as changed.
1574 Otherwise, if children were never requested, consider
1575 it as unchanged -- presumably, such varobj is not yet
1576 expanded in the UI, so we need not bother getting
1578 if (!varobj_has_more (v
, 0))
1580 update_dynamic_varobj_children (v
, NULL
, NULL
, NULL
, NULL
,
1581 &dummy
, false, 0, 0);
1582 if (varobj_has_more (v
, 0))
1587 result
.push_back (std::move (r
));
1592 /* If update_dynamic_varobj_children returns false, then we have
1593 a non-conforming pretty-printer, so we skip it. */
1594 if (update_dynamic_varobj_children (v
, &changed
, &type_changed_vec
,
1596 &unchanged
, &children_changed
,
1597 true, v
->from
, v
->to
))
1599 if (children_changed
|| !newobj_vec
.empty ())
1601 r
.children_changed
= true;
1602 r
.newobj
= std::move (newobj_vec
);
1604 /* Push in reverse order so that the first child is
1605 popped from the work stack first, and so will be
1606 added to result first. This does not affect
1607 correctness, just "nicer". */
1608 for (int i
= type_changed_vec
.size () - 1; i
>= 0; --i
)
1610 varobj_update_result
item (type_changed_vec
[i
]);
1612 /* Type may change only if value was changed. */
1613 item
.changed
= true;
1614 item
.type_changed
= true;
1615 item
.value_installed
= true;
1617 stack
.push_back (std::move (item
));
1619 for (int i
= changed
.size () - 1; i
>= 0; --i
)
1621 varobj_update_result
item (changed
[i
]);
1623 item
.changed
= true;
1624 item
.value_installed
= true;
1626 stack
.push_back (std::move (item
));
1628 for (int i
= unchanged
.size () - 1; i
>= 0; --i
)
1630 if (!unchanged
[i
]->frozen
)
1632 varobj_update_result
item (unchanged
[i
]);
1634 item
.value_installed
= true;
1636 stack
.push_back (std::move (item
));
1639 if (r
.changed
|| r
.children_changed
)
1640 result
.push_back (std::move (r
));
1646 /* Push any children. Use reverse order so that the first
1647 child is popped from the work stack first, and so
1648 will be added to result first. This does not
1649 affect correctness, just "nicer". */
1650 for (int i
= v
->children
.size () - 1; i
>= 0; --i
)
1652 varobj
*c
= v
->children
[i
];
1654 /* Child may be NULL if explicitly deleted by -var-delete. */
1655 if (c
!= NULL
&& !c
->frozen
)
1656 stack
.emplace_back (c
);
1659 if (r
.changed
|| r
.type_changed
)
1660 result
.push_back (std::move (r
));
1666 /* Helper functions */
1669 * Variable object construction/destruction
1673 delete_variable (struct varobj
*var
, bool only_children_p
)
1677 delete_variable_1 (&delcount
, var
, only_children_p
,
1678 true /* remove_from_parent_p */ );
1683 /* Delete the variable object VAR and its children. */
1684 /* IMPORTANT NOTE: If we delete a variable which is a child
1685 and the parent is not removed we dump core. It must be always
1686 initially called with remove_from_parent_p set. */
1688 delete_variable_1 (int *delcountp
, struct varobj
*var
, bool only_children_p
,
1689 bool remove_from_parent_p
)
1691 /* Delete any children of this variable, too. */
1692 for (varobj
*child
: var
->children
)
1697 if (!remove_from_parent_p
)
1698 child
->parent
= NULL
;
1700 delete_variable_1 (delcountp
, child
, false, only_children_p
);
1702 var
->children
.clear ();
1704 /* if we were called to delete only the children we are done here. */
1705 if (only_children_p
)
1708 /* Otherwise, add it to the list of deleted ones and proceed to do so. */
1709 /* If the name is empty, this is a temporary variable, that has not
1710 yet been installed, don't report it, it belongs to the caller... */
1711 if (!var
->obj_name
.empty ())
1713 *delcountp
= *delcountp
+ 1;
1716 /* If this variable has a parent, remove it from its parent's list. */
1717 /* OPTIMIZATION: if the parent of this variable is also being deleted,
1718 (as indicated by remove_from_parent_p) we don't bother doing an
1719 expensive list search to find the element to remove when we are
1720 discarding the list afterwards. */
1721 if ((remove_from_parent_p
) && (var
->parent
!= NULL
))
1722 var
->parent
->children
[var
->index
] = NULL
;
1724 if (!var
->obj_name
.empty ())
1725 uninstall_variable (var
);
1727 /* Free memory associated with this variable. */
1731 /* Install the given variable VAR with the object name VAR->OBJ_NAME. */
1733 install_variable (struct varobj
*var
)
1735 hashval_t hash
= htab_hash_string (var
->obj_name
.c_str ());
1736 void **slot
= htab_find_slot_with_hash (varobj_table
,
1737 var
->obj_name
.c_str (),
1739 if (*slot
!= nullptr)
1740 error (_("Duplicate variable object name"));
1742 /* Add varobj to hash table. */
1745 /* If root, add varobj to root list. */
1746 if (is_root_p (var
))
1747 rootlist
.push_front (var
->root
);
1750 /* Uninstall the object VAR. */
1752 uninstall_variable (struct varobj
*var
)
1754 hashval_t hash
= htab_hash_string (var
->obj_name
.c_str ());
1755 htab_remove_elt_with_hash (varobj_table
, var
->obj_name
.c_str (), hash
);
1758 fprintf_unfiltered (gdb_stdlog
, "Deleting %s\n", var
->obj_name
.c_str ());
1760 /* If root, remove varobj from root list. */
1761 if (is_root_p (var
))
1763 auto iter
= std::find (rootlist
.begin (), rootlist
.end (), var
->root
);
1764 rootlist
.erase (iter
);
1768 /* Create and install a child of the parent of the given name.
1770 The created VAROBJ takes ownership of the allocated NAME. */
1772 static struct varobj
*
1773 create_child (struct varobj
*parent
, int index
, std::string
&name
)
1775 struct varobj_item item
;
1777 std::swap (item
.name
, name
);
1778 item
.value
= release_value (value_of_child (parent
, index
));
1780 return create_child_with_value (parent
, index
, &item
);
1783 static struct varobj
*
1784 create_child_with_value (struct varobj
*parent
, int index
,
1785 struct varobj_item
*item
)
1787 varobj
*child
= new varobj (parent
->root
);
1789 /* NAME is allocated by caller. */
1790 std::swap (child
->name
, item
->name
);
1791 child
->index
= index
;
1792 child
->parent
= parent
;
1794 if (varobj_is_anonymous_child (child
))
1795 child
->obj_name
= string_printf ("%s.%d_anonymous",
1796 parent
->obj_name
.c_str (), index
);
1798 child
->obj_name
= string_printf ("%s.%s",
1799 parent
->obj_name
.c_str (),
1800 child
->name
.c_str ());
1802 install_variable (child
);
1804 /* Compute the type of the child. Must do this before
1805 calling install_new_value. */
1806 if (item
->value
!= NULL
)
1807 /* If the child had no evaluation errors, var->value
1808 will be non-NULL and contain a valid type. */
1809 child
->type
= value_actual_type (item
->value
.get (), 0, NULL
);
1811 /* Otherwise, we must compute the type. */
1812 child
->type
= (*child
->root
->lang_ops
->type_of_child
) (child
->parent
,
1814 install_new_value (child
, item
->value
.get (), 1);
1821 * Miscellaneous utility functions.
1824 /* Allocate memory and initialize a new variable. */
1825 varobj::varobj (varobj_root
*root_
)
1826 : root (root_
), dynamic (new varobj_dynamic
)
1830 /* Free any allocated memory associated with VAR. */
1837 if (var
->dynamic
->pretty_printer
!= NULL
)
1839 gdbpy_enter_varobj
enter_py (var
);
1841 Py_XDECREF (var
->dynamic
->constructor
);
1842 Py_XDECREF (var
->dynamic
->pretty_printer
);
1846 /* This must be deleted before the root object, because Python-based
1847 destructors need access to some components. */
1848 delete var
->dynamic
;
1850 if (is_root_p (var
))
1854 /* Return the type of the value that's stored in VAR,
1855 or that would have being stored there if the
1856 value were accessible.
1858 This differs from VAR->type in that VAR->type is always
1859 the true type of the expression in the source language.
1860 The return value of this function is the type we're
1861 actually storing in varobj, and using for displaying
1862 the values and for comparing previous and new values.
1864 For example, top-level references are always stripped. */
1866 varobj_get_value_type (const struct varobj
*var
)
1870 if (var
->value
!= nullptr)
1871 type
= value_type (var
->value
.get ());
1875 type
= check_typedef (type
);
1877 if (TYPE_IS_REFERENCE (type
))
1878 type
= get_target_type (type
);
1880 type
= check_typedef (type
);
1885 /* What is the default display for this variable? We assume that
1886 everything is "natural". Any exceptions? */
1887 static enum varobj_display_formats
1888 variable_default_display (struct varobj
*var
)
1890 return FORMAT_NATURAL
;
1894 * Language-dependencies
1897 /* Common entry points */
1899 /* Return the number of children for a given variable.
1900 The result of this function is defined by the language
1901 implementation. The number of children returned by this function
1902 is the number of children that the user will see in the variable
1905 number_of_children (const struct varobj
*var
)
1907 return (*var
->root
->lang_ops
->number_of_children
) (var
);
1910 /* What is the expression for the root varobj VAR? */
1913 name_of_variable (const struct varobj
*var
)
1915 return (*var
->root
->lang_ops
->name_of_variable
) (var
);
1918 /* What is the name of the INDEX'th child of VAR? */
1921 name_of_child (struct varobj
*var
, int index
)
1923 return (*var
->root
->lang_ops
->name_of_child
) (var
, index
);
1926 /* If frame associated with VAR can be found, switch
1927 to it and return true. Otherwise, return false. */
1930 check_scope (const struct varobj
*var
)
1932 struct frame_info
*fi
;
1935 fi
= frame_find_by_id (var
->root
->frame
);
1940 CORE_ADDR pc
= get_frame_pc (fi
);
1942 if (pc
< BLOCK_START (var
->root
->valid_block
) ||
1943 pc
>= BLOCK_END (var
->root
->valid_block
))
1951 /* Helper function to value_of_root. */
1953 static struct value
*
1954 value_of_root_1 (struct varobj
**var_handle
)
1956 struct value
*new_val
= NULL
;
1957 struct varobj
*var
= *var_handle
;
1958 bool within_scope
= false;
1960 /* Only root variables can be updated... */
1961 if (!is_root_p (var
))
1962 /* Not a root var. */
1965 scoped_restore_current_thread restore_thread
;
1967 /* Determine whether the variable is still around. */
1968 if (var
->root
->valid_block
== NULL
|| var
->root
->floating
)
1969 within_scope
= true;
1970 else if (var
->root
->thread_id
== 0)
1972 /* The program was single-threaded when the variable object was
1973 created. Technically, it's possible that the program became
1974 multi-threaded since then, but we don't support such
1976 within_scope
= check_scope (var
);
1980 thread_info
*thread
= find_thread_global_id (var
->root
->thread_id
);
1984 switch_to_thread (thread
);
1985 within_scope
= check_scope (var
);
1992 /* We need to catch errors here, because if evaluate
1993 expression fails we want to just return NULL. */
1996 new_val
= evaluate_expression (var
->root
->exp
.get ());
1998 catch (const gdb_exception_error
&except
)
2006 /* What is the ``struct value *'' of the root variable VAR?
2007 For floating variable object, evaluation can get us a value
2008 of different type from what is stored in varobj already. In
2010 - *type_changed will be set to 1
2011 - old varobj will be freed, and new one will be
2012 created, with the same name.
2013 - *var_handle will be set to the new varobj
2014 Otherwise, *type_changed will be set to 0. */
2015 static struct value
*
2016 value_of_root (struct varobj
**var_handle
, bool *type_changed
)
2020 if (var_handle
== NULL
)
2025 /* This should really be an exception, since this should
2026 only get called with a root variable. */
2028 if (!is_root_p (var
))
2031 if (var
->root
->floating
)
2033 struct varobj
*tmp_var
;
2035 tmp_var
= varobj_create (NULL
, var
->name
.c_str (), (CORE_ADDR
) 0,
2036 USE_SELECTED_FRAME
);
2037 if (tmp_var
== NULL
)
2041 std::string old_type
= varobj_get_type (var
);
2042 std::string new_type
= varobj_get_type (tmp_var
);
2043 if (old_type
== new_type
)
2045 /* The expression presently stored inside var->root->exp
2046 remembers the locations of local variables relatively to
2047 the frame where the expression was created (in DWARF location
2048 button, for example). Naturally, those locations are not
2049 correct in other frames, so update the expression. */
2051 std::swap (var
->root
->exp
, tmp_var
->root
->exp
);
2053 varobj_delete (tmp_var
, 0);
2058 tmp_var
->obj_name
= var
->obj_name
;
2059 tmp_var
->from
= var
->from
;
2060 tmp_var
->to
= var
->to
;
2061 varobj_delete (var
, 0);
2063 install_variable (tmp_var
);
2064 *var_handle
= tmp_var
;
2066 *type_changed
= true;
2075 struct value
*value
;
2077 value
= value_of_root_1 (var_handle
);
2078 if (var
->value
== NULL
|| value
== NULL
)
2080 /* For root varobj-s, a NULL value indicates a scoping issue.
2081 So, nothing to do in terms of checking for mutations. */
2083 else if (varobj_value_has_mutated (var
, value
, value_type (value
)))
2085 /* The type has mutated, so the children are no longer valid.
2086 Just delete them, and tell our caller that the type has
2088 varobj_delete (var
, 1 /* only_children */);
2089 var
->num_children
= -1;
2092 *type_changed
= true;
2098 /* What is the ``struct value *'' for the INDEX'th child of PARENT? */
2099 static struct value
*
2100 value_of_child (const struct varobj
*parent
, int index
)
2102 struct value
*value
;
2104 value
= (*parent
->root
->lang_ops
->value_of_child
) (parent
, index
);
2109 /* GDB already has a command called "value_of_variable". Sigh. */
2111 my_value_of_variable (struct varobj
*var
, enum varobj_display_formats format
)
2113 if (var
->root
->is_valid
)
2115 if (var
->dynamic
->pretty_printer
!= NULL
)
2116 return varobj_value_get_print_value (var
->value
.get (), var
->format
,
2118 return (*var
->root
->lang_ops
->value_of_variable
) (var
, format
);
2121 return std::string ();
2125 varobj_formatted_print_options (struct value_print_options
*opts
,
2126 enum varobj_display_formats format
)
2128 get_formatted_print_options (opts
, format_code
[(int) format
]);
2129 opts
->deref_ref
= 0;
2130 opts
->raw
= !pretty_printing
;
2134 varobj_value_get_print_value (struct value
*value
,
2135 enum varobj_display_formats format
,
2136 const struct varobj
*var
)
2138 struct value_print_options opts
;
2139 struct type
*type
= NULL
;
2141 gdb::unique_xmalloc_ptr
<char> encoding
;
2142 /* Initialize it just to avoid a GCC false warning. */
2143 CORE_ADDR str_addr
= 0;
2144 bool string_print
= false;
2147 return std::string ();
2150 std::string thevalue
;
2153 if (gdb_python_initialized
)
2155 PyObject
*value_formatter
= var
->dynamic
->pretty_printer
;
2157 gdbpy_enter_varobj
enter_py (var
);
2159 if (value_formatter
)
2161 /* First check to see if we have any children at all. If so,
2162 we simply return {...}. */
2163 if (dynamic_varobj_has_child_method (var
))
2166 if (PyObject_HasAttr (value_formatter
, gdbpy_to_string_cst
))
2168 struct value
*replacement
;
2170 gdbpy_ref
<> output
= apply_varobj_pretty_printer (value_formatter
,
2174 /* If we have string like output ... */
2177 /* If this is a lazy string, extract it. For lazy
2178 strings we always print as a string, so set
2180 if (gdbpy_is_lazy_string (output
.get ()))
2182 gdbpy_extract_lazy_string (output
.get (), &str_addr
,
2183 &type
, &len
, &encoding
);
2184 string_print
= true;
2188 /* If it is a regular (non-lazy) string, extract
2189 it and copy the contents into THEVALUE. If the
2190 hint says to print it as a string, set
2191 string_print. Otherwise just return the extracted
2192 string as a value. */
2194 gdb::unique_xmalloc_ptr
<char> s
2195 = python_string_to_target_string (output
.get ());
2199 struct gdbarch
*gdbarch
;
2201 gdb::unique_xmalloc_ptr
<char> hint
2202 = gdbpy_get_display_hint (value_formatter
);
2205 if (!strcmp (hint
.get (), "string"))
2206 string_print
= true;
2209 thevalue
= std::string (s
.get ());
2210 len
= thevalue
.size ();
2211 gdbarch
= value_type (value
)->arch ();
2212 type
= builtin_type (gdbarch
)->builtin_char
;
2218 gdbpy_print_stack ();
2221 /* If the printer returned a replacement value, set VALUE
2222 to REPLACEMENT. If there is not a replacement value,
2223 just use the value passed to this function. */
2225 value
= replacement
;
2231 varobj_formatted_print_options (&opts
, format
);
2233 /* If the THEVALUE has contents, it is a regular string. */
2234 if (!thevalue
.empty ())
2235 LA_PRINT_STRING (&stb
, type
, (gdb_byte
*) thevalue
.c_str (),
2236 len
, encoding
.get (), 0, &opts
);
2237 else if (string_print
)
2238 /* Otherwise, if string_print is set, and it is not a regular
2239 string, it is a lazy string. */
2240 val_print_string (type
, encoding
.get (), str_addr
, len
, &stb
, &opts
);
2242 /* All other cases. */
2243 common_val_print (value
, &stb
, 0, &opts
, current_language
);
2245 return std::move (stb
.string ());
2249 varobj_editable_p (const struct varobj
*var
)
2253 if (!(var
->root
->is_valid
&& var
->value
!= nullptr
2254 && VALUE_LVAL (var
->value
.get ())))
2257 type
= varobj_get_value_type (var
);
2259 switch (type
->code ())
2261 case TYPE_CODE_STRUCT
:
2262 case TYPE_CODE_UNION
:
2263 case TYPE_CODE_ARRAY
:
2264 case TYPE_CODE_FUNC
:
2265 case TYPE_CODE_METHOD
:
2275 /* Call VAR's value_is_changeable_p language-specific callback. */
2278 varobj_value_is_changeable_p (const struct varobj
*var
)
2280 return var
->root
->lang_ops
->value_is_changeable_p (var
);
2283 /* Return true if that varobj is floating, that is is always evaluated in the
2284 selected frame, and not bound to thread/frame. Such variable objects
2285 are created using '@' as frame specifier to -var-create. */
2287 varobj_floating_p (const struct varobj
*var
)
2289 return var
->root
->floating
;
2292 /* Implement the "value_is_changeable_p" varobj callback for most
2296 varobj_default_value_is_changeable_p (const struct varobj
*var
)
2301 if (CPLUS_FAKE_CHILD (var
))
2304 type
= varobj_get_value_type (var
);
2306 switch (type
->code ())
2308 case TYPE_CODE_STRUCT
:
2309 case TYPE_CODE_UNION
:
2310 case TYPE_CODE_ARRAY
:
2321 /* Iterate all the existing _root_ VAROBJs and call the FUNC callback
2325 all_root_varobjs (gdb::function_view
<void (struct varobj
*var
)> func
)
2327 /* Iterate "safely" - handle if the callee deletes its passed VAROBJ. */
2328 auto iter
= rootlist
.begin ();
2329 auto end
= rootlist
.end ();
2333 func ((*self
)->rootvar
);
2337 /* Invalidate varobj VAR if it is tied to locals and re-create it if it is
2338 defined on globals. It is a helper for varobj_invalidate.
2340 This function is called after changing the symbol file, in this case the
2341 pointers to "struct type" stored by the varobj are no longer valid. All
2342 varobj must be either re-evaluated, or marked as invalid here. */
2345 varobj_invalidate_iter (struct varobj
*var
)
2347 /* global and floating var must be re-evaluated. */
2348 if (var
->root
->floating
|| var
->root
->valid_block
== NULL
)
2350 struct varobj
*tmp_var
;
2352 /* Try to create a varobj with same expression. If we succeed
2353 replace the old varobj, otherwise invalidate it. */
2354 tmp_var
= varobj_create (NULL
, var
->name
.c_str (), (CORE_ADDR
) 0,
2356 if (tmp_var
!= NULL
)
2358 tmp_var
->obj_name
= var
->obj_name
;
2359 varobj_delete (var
, 0);
2360 install_variable (tmp_var
);
2363 var
->root
->is_valid
= false;
2365 else /* locals must be invalidated. */
2366 var
->root
->is_valid
= false;
2369 /* Invalidate the varobjs that are tied to locals and re-create the ones that
2370 are defined on globals.
2371 Invalidated varobjs will be always printed in_scope="invalid". */
2374 varobj_invalidate (void)
2376 all_root_varobjs (varobj_invalidate_iter
);
2379 /* A hash function for a varobj. */
2382 hash_varobj (const void *a
)
2384 const varobj
*obj
= (const varobj
*) a
;
2385 return htab_hash_string (obj
->obj_name
.c_str ());
2388 /* A hash table equality function for varobjs. */
2391 eq_varobj_and_string (const void *a
, const void *b
)
2393 const varobj
*obj
= (const varobj
*) a
;
2394 const char *name
= (const char *) b
;
2396 return obj
->obj_name
== name
;
2399 void _initialize_varobj ();
2401 _initialize_varobj ()
2403 varobj_table
= htab_create_alloc (5, hash_varobj
, eq_varobj_and_string
,
2404 nullptr, xcalloc
, xfree
);
2406 add_setshow_zuinteger_cmd ("varobj", class_maintenance
,
2408 _("Set varobj debugging."),
2409 _("Show varobj debugging."),
2410 _("When non-zero, varobj debugging is enabled."),
2411 NULL
, show_varobjdebug
,
2412 &setdebuglist
, &showdebuglist
);