gdb/varobj.h

   1 /* GDB variable objects API.
   2    Copyright (C) 1999-2020 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 #define default_varobj_ops c_varobj_ops
 237
 238 /* Non-zero if we want to see trace of varobj level stuff.  */
 239
 240 extern unsigned int varobjdebug;
 241
 242 /* API functions */
 243
 244 extern struct varobj *varobj_create (const char *objname,
 245                                      const char *expression, CORE_ADDR frame,
 246                                      enum varobj_type type);
 247
 248 extern std::string varobj_gen_name (void);
 249
 250 extern struct varobj *varobj_get_handle (const char *name);
 251
 252 extern const char *varobj_get_objname (const struct varobj *var);
 253
 254 extern std::string varobj_get_expression (const struct varobj *var);
 255
 256 /* Delete a varobj and all its children if only_children is false, otherwise
 257    delete only the children.  Return the number of deleted variables.  */
 258
 259 extern int varobj_delete (struct varobj *var, bool only_children);
 260
 261 extern enum varobj_display_formats varobj_set_display_format (
 262                                                          struct varobj *var,
 263                                         enum varobj_display_formats format);
 264
 265 extern enum varobj_display_formats varobj_get_display_format (
 266                                                 const struct varobj *var);
 267
 268 extern int varobj_get_thread_id (const struct varobj *var);
 269
 270 extern void varobj_set_frozen (struct varobj *var, bool frozen);
 271
 272 extern bool varobj_get_frozen (const struct varobj *var);
 273
 274 extern void varobj_get_child_range (const struct varobj *var, int *from,
 275                                     int *to);
 276
 277 extern void varobj_set_child_range (struct varobj *var, int from, int to);
 278
 279 extern gdb::unique_xmalloc_ptr<char>
 280      varobj_get_display_hint (const struct varobj *var);
 281
 282 extern int varobj_get_num_children (struct varobj *var);
 283
 284 /* Return the list of children of VAR.  The returned vector should not
 285    be modified in any way.  FROM and TO are in/out parameters
 286    indicating the range of children to return.  If either *FROM or *TO
 287    is less than zero on entry, then all children will be returned.  On
 288    return, *FROM and *TO will be updated to indicate the real range
 289    that was returned.  The resulting vector will contain at least the
 290    children from *FROM to just before *TO; it might contain more
 291    children, depending on whether any more were available.  */
 292 extern const std::vector<varobj *> &
 293   varobj_list_children (struct varobj *var, int *from, int *to);
 294
 295 extern std::string varobj_get_type (struct varobj *var);
 296
 297 extern struct type *varobj_get_gdb_type (const struct varobj *var);
 298
 299 extern const char *varobj_get_path_expr (const struct varobj *var);
 300
 301 extern const struct language_defn *
 302   varobj_get_language (const struct varobj *var);
 303
 304 extern int varobj_get_attributes (const struct varobj *var);
 305
 306 extern std::string
 307   varobj_get_formatted_value (struct varobj *var,
 308                               enum varobj_display_formats format);
 309
 310 extern std::string varobj_get_value (struct varobj *var);
 311
 312 extern bool varobj_set_value (struct varobj *var, const char *expression);
 313
 314 extern void all_root_varobjs (void (*func) (struct varobj *var, void *data),
 315                               void *data);
 316
 317 extern std::vector<varobj_update_result>
 318   varobj_update (struct varobj **varp, bool is_explicit);
 319
 320 extern void varobj_invalidate (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 */