xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/varobj.h (revision 8b657b0747480f8989760d71343d6dd33f8d4cf9)
1 /* GDB variable objects API.
2    Copyright (C) 1999-2023 Free Software Foundation, Inc.
3 
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 3 of the License, or
7    (at your option) any later version.
8 
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
16 
17 #ifndef VAROBJ_H
18 #define VAROBJ_H 1
19 
20 #include "symtab.h"
21 #include "gdbtypes.h"
22 #include "value.h"
23 
24 /* Enumeration for the format types */
25 enum varobj_display_formats
26   {
27     FORMAT_NATURAL,		/* What gdb actually calls 'natural' */
28     FORMAT_BINARY,		/* Binary display                    */
29     FORMAT_DECIMAL,		/* Decimal display                   */
30     FORMAT_HEXADECIMAL,		/* Hex display                       */
31     FORMAT_OCTAL,		/* Octal display                     */
32     FORMAT_ZHEXADECIMAL		/* Zero padded hexadecimal	     */
33   };
34 
35 enum varobj_type
36   {
37     USE_SPECIFIED_FRAME,        /* Use the frame passed to varobj_create.  */
38     USE_CURRENT_FRAME,          /* Use the current frame.  */
39     USE_SELECTED_FRAME          /* Always reevaluate in selected frame.  */
40   };
41 
42 /* Enumerator describing if a variable object is in scope.  */
43 enum varobj_scope_status
44   {
45     VAROBJ_IN_SCOPE = 0,        /* Varobj is scope, value available.  */
46     VAROBJ_NOT_IN_SCOPE = 1,    /* Varobj is not in scope, value not
47 				   available, but varobj can become in
48 				   scope later.  */
49     VAROBJ_INVALID = 2,         /* Varobj no longer has any value, and never
50 				   will.  */
51   };
52 
53 /* String representations of gdb's format codes (defined in varobj.c).  */
54 extern const char *varobj_format_string[];
55 
56 /* Struct that describes a variable object instance.  */
57 
58 struct varobj;
59 
60 struct varobj_update_result
61 {
62   varobj_update_result (struct varobj *varobj_,
63 			varobj_scope_status status_ = VAROBJ_IN_SCOPE)
64   : varobj (varobj_), status (status_)
65   {}
66 
67   varobj_update_result (varobj_update_result &&other) = default;
68 
69   DISABLE_COPY_AND_ASSIGN (varobj_update_result);
70 
71   struct varobj *varobj;
72   bool type_changed = false;
73   bool children_changed = false;
74   bool changed = false;
75   enum varobj_scope_status status;
76   /* This variable is used internally by varobj_update to indicate if the
77      new value of varobj is already computed and installed, or has to
78      be yet installed.  Don't use this outside varobj.c.  */
79   bool value_installed = false;
80 
81   /* This will be non-NULL when new children were added to the varobj.
82      It lists the new children (which must necessarily come at the end
83      of the child list) added during an update.  The caller is
84      responsible for freeing this vector.  */
85   std::vector<struct varobj *> newobj;
86 };
87 
88 struct varobj_root;
89 struct varobj_dynamic;
90 
91 /* Every variable in the system has a structure of this type defined
92    for it.  This structure holds all information necessary to manipulate
93    a particular object variable.  */
94 struct varobj
95 {
96   explicit varobj (varobj_root *root_);
97   ~varobj ();
98 
99   /* Name of the variable for this object.  If this variable is a
100      child, then this name will be the child's source name.
101      (bar, not foo.bar).  */
102   /* NOTE: This is the "expression".  */
103   std::string name;
104 
105   /* Expression for this child.  Can be used to create a root variable
106      corresponding to this child.  */
107   std::string path_expr;
108 
109   /* The name for this variable's object.  This is here for
110      convenience when constructing this object's children.  */
111   std::string obj_name;
112 
113   /* Index of this variable in its parent or -1.  */
114   int index = -1;
115 
116   /* The type of this variable.  This can be NULL
117      for artificial variable objects -- currently, the "accessibility"
118      variable objects in C++.  */
119   struct type *type = NULL;
120 
121   /* The value of this expression or subexpression.  A NULL value
122      indicates there was an error getting this value.
123      Invariant: if varobj_value_is_changeable_p (this) is non-zero,
124      the value is either NULL, or not lazy.  */
125   value_ref_ptr value;
126 
127   /* The number of (immediate) children this variable has.  */
128   int num_children = -1;
129 
130   /* If this object is a child, this points to its immediate parent.  */
131   struct varobj *parent = NULL;
132 
133   /* Children of this object.  */
134   std::vector<varobj *> children;
135 
136   /* Description of the root variable.  Points to root variable for
137      children.  */
138   struct varobj_root *root;
139 
140   /* The format of the output for this object.  */
141   enum varobj_display_formats format = FORMAT_NATURAL;
142 
143   /* Was this variable updated via a varobj_set_value operation.  */
144   bool updated = false;
145 
146   /* Last print value.  */
147   std::string print_value;
148 
149   /* Is this variable frozen.  Frozen variables are never implicitly
150      updated by -var-update *
151      or -var-update <direct-or-indirect-parent>.  */
152   bool frozen = false;
153 
154   /* Is the value of this variable intentionally not fetched?  It is
155      not fetched if either the variable is frozen, or any parents is
156      frozen.  */
157   bool not_fetched = false;
158 
159   /* Sub-range of children which the MI consumer has requested.  If
160      FROM < 0 or TO < 0, means that all children have been
161      requested.  */
162   int from = -1;
163   int to = -1;
164 
165   /* Dynamic part of varobj.  */
166   struct varobj_dynamic *dynamic;
167 };
168 
169 /* Is the variable X one of our "fake" children?  */
170 #define CPLUS_FAKE_CHILD(x) \
171 ((x) != NULL && (x)->type == NULL && (x)->value == NULL)
172 
173 /* The language specific vector */
174 
175 struct lang_varobj_ops
176 {
177   /* The number of children of PARENT.  */
178   int (*number_of_children) (const struct varobj *parent);
179 
180   /* The name (expression) of a root varobj.  */
181   std::string (*name_of_variable) (const struct varobj *parent);
182 
183   /* The name of the INDEX'th child of PARENT.  */
184   std::string (*name_of_child) (const struct varobj *parent, int index);
185 
186   /* Returns the rooted expression of CHILD, which is a variable
187      obtain that has some parent.  */
188   std::string (*path_expr_of_child) (const struct varobj *child);
189 
190   /* The ``struct value *'' of the INDEX'th child of PARENT.  */
191   struct value *(*value_of_child) (const struct varobj *parent, int index);
192 
193   /* The type of the INDEX'th child of PARENT.  */
194   struct type *(*type_of_child) (const struct varobj *parent, int index);
195 
196   /* The current value of VAR.  */
197   std::string (*value_of_variable) (const struct varobj *var,
198 				    enum varobj_display_formats format);
199 
200   /* Return true if changes in value of VAR must be detected and
201      reported by -var-update.  Return false if -var-update should never
202      report changes of such values.  This makes sense for structures
203      (since the changes in children values will be reported separately),
204      or for artificial objects (like 'public' pseudo-field in C++).
205 
206      Return value of false means that gdb need not call value_fetch_lazy
207      for the value of this variable object.  */
208   bool (*value_is_changeable_p) (const struct varobj *var);
209 
210   /* Return true if the type of VAR has mutated.
211 
212      VAR's value is still the varobj's previous value, while NEW_VALUE
213      is VAR's new value and NEW_TYPE is the var's new type.  NEW_VALUE
214      may be NULL indicating that there is no value available (the varobj
215      may be out of scope, of may be the child of a null pointer, for
216      instance).  NEW_TYPE, on the other hand, must never be NULL.
217 
218      This function should also be able to assume that var's number of
219      children is set (not < 0).
220 
221      Languages where types do not mutate can set this to NULL.  */
222   bool (*value_has_mutated) (const struct varobj *var, struct value *new_value,
223 			     struct type *new_type);
224 
225   /* Return true if VAR is a suitable path expression parent.
226 
227      For C like languages with anonymous structures and unions an anonymous
228      structure or union is not a suitable parent.  */
229   bool (*is_path_expr_parent) (const struct varobj *var);
230 };
231 
232 extern const struct lang_varobj_ops c_varobj_ops;
233 extern const struct lang_varobj_ops cplus_varobj_ops;
234 extern const struct lang_varobj_ops ada_varobj_ops;
235 
236 /* Non-zero if we want to see trace of varobj level stuff.  */
237 
238 extern unsigned int varobjdebug;
239 
240 /* API functions */
241 
242 extern struct varobj *varobj_create (const char *objname,
243 				     const char *expression, CORE_ADDR frame,
244 				     enum varobj_type type);
245 
246 extern std::string varobj_gen_name (void);
247 
248 extern struct varobj *varobj_get_handle (const char *name);
249 
250 extern const char *varobj_get_objname (const struct varobj *var);
251 
252 extern std::string varobj_get_expression (const struct varobj *var);
253 
254 /* Delete a varobj and all its children if only_children is false, otherwise
255    delete only the children.  Return the number of deleted variables.  */
256 
257 extern int varobj_delete (struct varobj *var, bool only_children);
258 
259 extern enum varobj_display_formats varobj_set_display_format (
260 							 struct varobj *var,
261 					enum varobj_display_formats format);
262 
263 extern enum varobj_display_formats varobj_get_display_format (
264 						const struct varobj *var);
265 
266 extern int varobj_get_thread_id (const struct varobj *var);
267 
268 extern void varobj_set_frozen (struct varobj *var, bool frozen);
269 
270 extern bool varobj_get_frozen (const struct varobj *var);
271 
272 extern void varobj_get_child_range (const struct varobj *var, int *from,
273 				    int *to);
274 
275 extern void varobj_set_child_range (struct varobj *var, int from, int to);
276 
277 extern gdb::unique_xmalloc_ptr<char>
278      varobj_get_display_hint (const struct varobj *var);
279 
280 extern int varobj_get_num_children (struct varobj *var);
281 
282 /* Return the list of children of VAR.  The returned vector should not
283    be modified in any way.  FROM and TO are in/out parameters
284    indicating the range of children to return.  If either *FROM or *TO
285    is less than zero on entry, then all children will be returned.  On
286    return, *FROM and *TO will be updated to indicate the real range
287    that was returned.  The resulting vector will contain at least the
288    children from *FROM to just before *TO; it might contain more
289    children, depending on whether any more were available.  */
290 extern const std::vector<varobj *> &
291   varobj_list_children (struct varobj *var, int *from, int *to);
292 
293 extern std::string varobj_get_type (struct varobj *var);
294 
295 extern struct type *varobj_get_gdb_type (const struct varobj *var);
296 
297 extern const char *varobj_get_path_expr (const struct varobj *var);
298 
299 extern const struct language_defn *
300   varobj_get_language (const struct varobj *var);
301 
302 extern int varobj_get_attributes (const struct varobj *var);
303 
304 extern std::string
305   varobj_get_formatted_value (struct varobj *var,
306 			      enum varobj_display_formats format);
307 
308 extern std::string varobj_get_value (struct varobj *var);
309 
310 extern bool varobj_set_value (struct varobj *var, const char *expression);
311 
312 extern void all_root_varobjs (gdb::function_view<void (struct varobj *var)>);
313 
314 extern std::vector<varobj_update_result>
315   varobj_update (struct varobj **varp, bool is_explicit);
316 
317 /* Try to recreate any global or floating varobj.  This is called after
318    changing symbol files.  */
319 
320 extern void varobj_re_set (void);
321 
322 extern bool varobj_editable_p (const struct varobj *var);
323 
324 extern bool varobj_floating_p (const struct varobj *var);
325 
326 extern void varobj_set_visualizer (struct varobj *var,
327 				   const char *visualizer);
328 
329 extern void varobj_enable_pretty_printing (void);
330 
331 extern bool varobj_has_more (const struct varobj *var, int to);
332 
333 extern bool varobj_is_dynamic_p (const struct varobj *var);
334 
335 extern bool varobj_default_value_is_changeable_p (const struct varobj *var);
336 extern bool varobj_value_is_changeable_p (const struct varobj *var);
337 
338 extern struct type *varobj_get_value_type (const struct varobj *var);
339 
340 extern bool varobj_is_anonymous_child (const struct varobj *child);
341 
342 extern const struct varobj *
343   varobj_get_path_expr_parent (const struct varobj *var);
344 
345 extern std::string
346   varobj_value_get_print_value (struct value *value,
347 				enum varobj_display_formats format,
348 				const struct varobj *var);
349 
350 extern void varobj_formatted_print_options (struct value_print_options *opts,
351 					    enum varobj_display_formats format);
352 
353 extern void varobj_restrict_range (const std::vector<varobj *> &children,
354 				   int *from, int *to);
355 
356 extern bool varobj_default_is_path_expr_parent (const struct varobj *var);
357 
358 #endif /* VAROBJ_H */
359