gdb/varobj.h

   1 /* GDB variable objects API.
   2    Copyright (C) 1999-2019 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 "common/vec.h"
  23 #include "value.h"
  24
  25 /* Enumeration for the format types */
  26 enum varobj_display_formats
  27   {
  28     FORMAT_NATURAL,             /* What gdb actually calls 'natural' */
  29     FORMAT_BINARY,              /* Binary display                    */
  30     FORMAT_DECIMAL,             /* Decimal display                   */
  31     FORMAT_HEXADECIMAL,         /* Hex display                       */
  32     FORMAT_OCTAL,               /* Octal display                     */
  33     FORMAT_ZHEXADECIMAL         /* Zero padded hexadecimal           */
  34   };
  35
  36 enum varobj_type
  37   {
  38     USE_SPECIFIED_FRAME,        /* Use the frame passed to varobj_create.  */
  39     USE_CURRENT_FRAME,          /* Use the current frame.  */
  40     USE_SELECTED_FRAME          /* Always reevaluate in selected frame.  */
  41   };
  42
  43 /* Enumerator describing if a variable object is in scope.  */
  44 enum varobj_scope_status
  45   {
  46     VAROBJ_IN_SCOPE = 0,        /* Varobj is scope, value available.  */
  47     VAROBJ_NOT_IN_SCOPE = 1,    /* Varobj is not in scope, value not
  48                                    available, but varobj can become in
  49                                    scope later.  */
  50     VAROBJ_INVALID = 2,         /* Varobj no longer has any value, and never
  51                                    will.  */
  52   };
  53
  54 /* String representations of gdb's format codes (defined in varobj.c).  */
  55 extern const char *varobj_format_string[];
  56
  57 /* Struct that describes a variable object instance.  */
  58
  59 struct varobj;
  60
  61 struct varobj_update_result
  62 {
  63   varobj_update_result (struct varobj *varobj_,
  64                         varobj_scope_status status_ = VAROBJ_IN_SCOPE)
  65   : varobj (varobj_), status (status_)
  66   {}
  67
  68   varobj_update_result (varobj_update_result &&other) = default;
  69
  70   DISABLE_COPY_AND_ASSIGN (varobj_update_result);
  71
  72   struct varobj *varobj;
  73   bool type_changed = false;
  74   bool children_changed = false;
  75   bool changed = false;
  76   enum varobj_scope_status status;
  77   /* This variable is used internally by varobj_update to indicate if the
  78      new value of varobj is already computed and installed, or has to
  79      be yet installed.  Don't use this outside varobj.c.  */
  80   bool value_installed = false;
  81
  82   /* This will be non-NULL when new children were added to the varobj.
  83      It lists the new children (which must necessarily come at the end
  84      of the child list) added during an update.  The caller is
  85      responsible for freeing this vector.  */
  86   std::vector<struct varobj *> newobj;
  87 };
  88
  89 struct varobj_root;
  90 struct varobj_dynamic;
  91
  92 /* Every variable in the system has a structure of this type defined
  93    for it.  This structure holds all information necessary to manipulate
  94    a particular object variable.  */
  95 struct varobj
  96 {
  97   explicit varobj (varobj_root *root_);
  98   ~varobj ();
  99
 100   /* Name of the variable for this object.  If this variable is a
 101      child, then this name will be the child's source name.
 102      (bar, not foo.bar).  */
 103   /* NOTE: This is the "expression".  */
 104   std::string name;
 105
 106   /* Expression for this child.  Can be used to create a root variable
 107      corresponding to this child.  */
 108   std::string path_expr;
 109
 110   /* The name for this variable's object.  This is here for
 111      convenience when constructing this object's children.  */
 112   std::string obj_name;
 113
 114   /* Index of this variable in its parent or -1.  */
 115   int index = -1;
 116
 117   /* The type of this variable.  This can be NULL
 118      for artificial variable objects -- currently, the "accessibility"
 119      variable objects in C++.  */
 120   struct type *type = NULL;
 121
 122   /* The value of this expression or subexpression.  A NULL value
 123      indicates there was an error getting this value.
 124      Invariant: if varobj_value_is_changeable_p (this) is non-zero,
 125      the value is either NULL, or not lazy.  */
 126   value_ref_ptr value;
 127
 128   /* The number of (immediate) children this variable has.  */
 129   int num_children = -1;
 130
 131   /* If this object is a child, this points to its immediate parent.  */
 132   struct varobj *parent = NULL;
 133
 134   /* Children of this object.  */
 135   std::vector<varobj *> children;
 136
 137   /* Description of the root variable.  Points to root variable for
 138      children.  */
 139   struct varobj_root *root;
 140
 141   /* The format of the output for this object.  */
 142   enum varobj_display_formats format = FORMAT_NATURAL;
 143
 144   /* Was this variable updated via a varobj_set_value operation.  */
 145   bool updated = false;
 146
 147   /* Last print value.  */
 148   std::string print_value;
 149
 150   /* Is this variable frozen.  Frozen variables are never implicitly
 151      updated by -var-update *
 152      or -var-update <direct-or-indirect-parent>.  */
 153   bool frozen = false;
 154
 155   /* Is the value of this variable intentionally not fetched?  It is
 156      not fetched if either the variable is frozen, or any parents is
 157      frozen.  */
 158   bool not_fetched = false;
 159
 160   /* Sub-range of children which the MI consumer has requested.  If
 161      FROM < 0 or TO < 0, means that all children have been
 162      requested.  */
 163   int from = -1;
 164   int to = -1;
 165
 166   /* Dynamic part of varobj.  */
 167   struct varobj_dynamic *dynamic;
 168 };
 169
 170 /* Is the variable X one of our "fake" children?  */
 171 #define CPLUS_FAKE_CHILD(x) \
 172 ((x) != NULL && (x)->type == NULL && (x)->value == NULL)
 173
 174 /* The language specific vector */
 175
 176 struct lang_varobj_ops
 177 {
 178   /* The number of children of PARENT.  */
 179   int (*number_of_children) (const struct varobj *parent);
 180
 181   /* The name (expression) of a root varobj.  */
 182   std::string (*name_of_variable) (const struct varobj *parent);
 183
 184   /* The name of the INDEX'th child of PARENT.  */
 185   std::string (*name_of_child) (const struct varobj *parent, int index);
 186
 187   /* Returns the rooted expression of CHILD, which is a variable
 188      obtain that has some parent.  */
 189   std::string (*path_expr_of_child) (const struct varobj *child);
 190
 191   /* The ``struct value *'' of the INDEX'th child of PARENT.  */
 192   struct value *(*value_of_child) (const struct varobj *parent, int index);
 193
 194   /* The type of the INDEX'th child of PARENT.  */
 195   struct type *(*type_of_child) (const struct varobj *parent, int index);
 196
 197   /* The current value of VAR.  */
 198   std::string (*value_of_variable) (const struct varobj *var,
 199                                     enum varobj_display_formats format);
 200
 201   /* Return true if changes in value of VAR must be detected and
 202      reported by -var-update.  Return false if -var-update should never
 203      report changes of such values.  This makes sense for structures
 204      (since the changes in children values will be reported separately),
 205      or for artificial objects (like 'public' pseudo-field in C++).
 206
 207      Return value of false means that gdb need not call value_fetch_lazy
 208      for the value of this variable object.  */
 209   bool (*value_is_changeable_p) (const struct varobj *var);
 210
 211   /* Return true if the type of VAR has mutated.
 212
 213      VAR's value is still the varobj's previous value, while NEW_VALUE
 214      is VAR's new value and NEW_TYPE is the var's new type.  NEW_VALUE
 215      may be NULL indicating that there is no value available (the varobj
 216      may be out of scope, of may be the child of a null pointer, for
 217      instance).  NEW_TYPE, on the other hand, must never be NULL.
 218
 219      This function should also be able to assume that var's number of
 220      children is set (not < 0).
 221
 222      Languages where types do not mutate can set this to NULL.  */
 223   bool (*value_has_mutated) (const struct varobj *var, struct value *new_value,
 224                              struct type *new_type);
 225
 226   /* Return true if VAR is a suitable path expression parent.
 227
 228      For C like languages with anonymous structures and unions an anonymous
 229      structure or union is not a suitable parent.  */
 230   bool (*is_path_expr_parent) (const struct varobj *var);
 231 };
 232
 233 extern const struct lang_varobj_ops c_varobj_ops;
 234 extern const struct lang_varobj_ops cplus_varobj_ops;
 235 extern const struct lang_varobj_ops ada_varobj_ops;
 236
 237 #define default_varobj_ops c_varobj_ops
 238 /* API functions */
 239
 240 extern struct varobj *varobj_create (const char *objname,
 241                                      const char *expression, CORE_ADDR frame,
 242                                      enum varobj_type type);
 243
 244 extern std::string varobj_gen_name (void);
 245
 246 extern struct varobj *varobj_get_handle (const char *name);
 247
 248 extern const char *varobj_get_objname (const struct varobj *var);
 249
 250 extern std::string varobj_get_expression (const struct varobj *var);
 251
 252 /* Delete a varobj and all its children if only_children is false, otherwise
 253    delete only the children.  Return the number of deleted variables.  */
 254
 255 extern int varobj_delete (struct varobj *var, bool only_children);
 256
 257 extern enum varobj_display_formats varobj_set_display_format (
 258                                                          struct varobj *var,
 259                                         enum varobj_display_formats format);
 260
 261 extern enum varobj_display_formats varobj_get_display_format (
 262                                                 const struct varobj *var);
 263
 264 extern int varobj_get_thread_id (const struct varobj *var);
 265
 266 extern void varobj_set_frozen (struct varobj *var, bool frozen);
 267
 268 extern bool varobj_get_frozen (const struct varobj *var);
 269
 270 extern void varobj_get_child_range (const struct varobj *var, int *from,
 271                                     int *to);
 272
 273 extern void varobj_set_child_range (struct varobj *var, int from, int to);
 274
 275 extern gdb::unique_xmalloc_ptr<char>
 276      varobj_get_display_hint (const struct varobj *var);
 277
 278 extern int varobj_get_num_children (struct varobj *var);
 279
 280 /* Return the list of children of VAR.  The returned vector should not
 281    be modified in any way.  FROM and TO are in/out parameters
 282    indicating the range of children to return.  If either *FROM or *TO
 283    is less than zero on entry, then all children will be returned.  On
 284    return, *FROM and *TO will be updated to indicate the real range
 285    that was returned.  The resulting VEC will contain at least the
 286    children from *FROM to just before *TO; it might contain more
 287    children, depending on whether any more were available.  */
 288 extern const std::vector<varobj *> &
 289   varobj_list_children (struct varobj *var, int *from, int *to);
 290
 291 extern std::string varobj_get_type (struct varobj *var);
 292
 293 extern struct type *varobj_get_gdb_type (const struct varobj *var);
 294
 295 extern const char *varobj_get_path_expr (const struct varobj *var);
 296
 297 extern const struct language_defn *
 298   varobj_get_language (const struct varobj *var);
 299
 300 extern int varobj_get_attributes (const struct varobj *var);
 301
 302 extern std::string
 303   varobj_get_formatted_value (struct varobj *var,
 304                               enum varobj_display_formats format);
 305
 306 extern std::string varobj_get_value (struct varobj *var);
 307
 308 extern bool varobj_set_value (struct varobj *var, const char *expression);
 309
 310 extern void all_root_varobjs (void (*func) (struct varobj *var, void *data),
 311                               void *data);
 312
 313 extern std::vector<varobj_update_result>
 314   varobj_update (struct varobj **varp, bool is_explicit);
 315
 316 extern void varobj_invalidate (void);
 317
 318 extern bool varobj_editable_p (const struct varobj *var);
 319
 320 extern bool varobj_floating_p (const struct varobj *var);
 321
 322 extern void varobj_set_visualizer (struct varobj *var,
 323                                    const char *visualizer);
 324
 325 extern void varobj_enable_pretty_printing (void);
 326
 327 extern bool varobj_has_more (const struct varobj *var, int to);
 328
 329 extern bool varobj_is_dynamic_p (const struct varobj *var);
 330
 331 extern bool varobj_default_value_is_changeable_p (const struct varobj *var);
 332 extern bool varobj_value_is_changeable_p (const struct varobj *var);
 333
 334 extern struct type *varobj_get_value_type (const struct varobj *var);
 335
 336 extern bool varobj_is_anonymous_child (const struct varobj *child);
 337
 338 extern const struct varobj *
 339   varobj_get_path_expr_parent (const struct varobj *var);
 340
 341 extern std::string
 342   varobj_value_get_print_value (struct value *value,
 343                                 enum varobj_display_formats format,
 344                                 const struct varobj *var);
 345
 346 extern void varobj_formatted_print_options (struct value_print_options *opts,
 347                                             enum varobj_display_formats format);
 348
 349 extern void varobj_restrict_range (const std::vector<varobj *> &children,
 350                                    int *from, int *to);
 351
 352 extern bool varobj_default_is_path_expr_parent (const struct varobj *var);
 353
 354 #endif /* VAROBJ_H */