gdb/top.h

   1 /* Top level stuff for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2022 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef TOP_H
  21 #define TOP_H
  22
  23 #include "gdbsupport/buffer.h"
  24 #include "gdbsupport/event-loop.h"
  25 #include "gdbsupport/next-iterator.h"
  26 #include "value.h"
  27
  28 /* Prompt state.  */
  29
  30 enum prompt_state
  31 {
  32   /* The command line is blocked simulating synchronous execution.
  33      This is used to implement the foreground execution commands
  34      ('run', 'continue', etc.).  We won't display the prompt and
  35      accept further commands until the execution is actually over.  */
  36   PROMPT_BLOCKED,
  37
  38   /* The command finished; display the prompt before returning back to
  39      the top level.  */
  40   PROMPT_NEEDED,
  41
  42   /* We've displayed the prompt already, ready for input.  */
  43   PROMPTED,
  44 };
  45
  46 /* All about a user interface instance.  Each user interface has its
  47    own I/O files/streams, readline state, its own top level
  48    interpreter (for the main UI, this is the interpreter specified
  49    with -i on the command line) and secondary interpreters (for
  50    interpreter-exec ...), etc.  There's always one UI associated with
  51    stdin/stdout/stderr, but the user can create secondary UIs, for
  52    example, to create a separate MI channel on its own stdio
  53    streams.  */
  54
  55 struct ui
  56 {
  57   /* Create a new UI.  */
  58   ui (FILE *instream, FILE *outstream, FILE *errstream);
  59   ~ui ();
  60
  61   DISABLE_COPY_AND_ASSIGN (ui);
  62
  63   /* Pointer to next in singly-linked list.  */
  64   struct ui *next;
  65
  66   /* Convenient handle (UI number).  Unique across all UIs.  */
  67   int num;
  68
  69   /* The UI's command line buffer.  This is to used to accumulate
  70      input until we have a whole command line.  */
  71   struct buffer line_buffer;
  72
  73   /* The callback used by the event loop whenever an event is detected
  74      on the UI's input file descriptor.  This function incrementally
  75      builds a buffer where it accumulates the line read up to the
  76      point of invocation.  In the special case in which the character
  77      read is newline, the function invokes the INPUT_HANDLER callback
  78      (see below).  */
  79   void (*call_readline) (gdb_client_data);
  80
  81   /* The function to invoke when a complete line of input is ready for
  82      processing.  */
  83   void (*input_handler) (gdb::unique_xmalloc_ptr<char> &&);
  84
  85   /* True if this UI is using the readline library for command
  86      editing; false if using GDB's own simple readline emulation, with
  87      no editing support.  */
  88   int command_editing;
  89
  90   /* Each UI has its own independent set of interpreters.  */
  91   struct ui_interp_info *interp_info;
  92
  93   /* True if the UI is in async mode, false if in sync mode.  If in
  94      sync mode, a synchronous execution command (e.g, "next") does not
  95      return until the command is finished.  If in async mode, then
  96      running a synchronous command returns right after resuming the
  97      target.  Waiting for the command's completion is later done on
  98      the top event loop.  For the main UI, this starts out disabled,
  99      until all the explicit command line arguments (e.g., `gdb -ex
 100      "start" -ex "next"') are processed.  */
 101   int async;
 102
 103   /* The number of nested readline secondary prompts that are
 104      currently active.  */
 105   int secondary_prompt_depth;
 106
 107   /* The UI's stdin.  Set to stdin for the main UI.  */
 108   FILE *stdin_stream;
 109
 110   /* stdio stream that command input is being read from.  Set to stdin
 111      normally.  Set by source_command to the file we are sourcing.
 112      Set to NULL if we are executing a user-defined command or
 113      interacting via a GUI.  */
 114   FILE *instream;
 115   /* Standard output stream.  */
 116   FILE *outstream;
 117   /* Standard error stream.  */
 118   FILE *errstream;
 119
 120   /* The file descriptor for the input stream, so that we can register
 121      it with the event loop.  */
 122   int input_fd;
 123
 124   /* Whether ISATTY returns true on input_fd.  Cached here because
 125      quit_force needs to know this _after_ input_fd might be
 126      closed.  */
 127   int input_interactive_p;
 128
 129   /* See enum prompt_state's description.  */
 130   enum prompt_state prompt_state;
 131
 132   /* The fields below that start with "m_" are "private".  They're
 133      meant to be accessed through wrapper macros that make them look
 134      like globals.  */
 135
 136   /* The ui_file streams.  */
 137   /* Normal results */
 138   struct ui_file *m_gdb_stdout;
 139   /* Input stream */
 140   struct ui_file *m_gdb_stdin;
 141   /* Serious error notifications */
 142   struct ui_file *m_gdb_stderr;
 143   /* Log/debug/trace messages that should bypass normal stdout/stderr
 144      filtering.  For moment, always call this stream using
 145      *_unfiltered.  In the very near future that restriction shall be
 146      removed - either call shall be unfiltered.  (cagney 1999-06-13).  */
 147   struct ui_file *m_gdb_stdlog;
 148
 149   /* The current ui_out.  */
 150   struct ui_out *m_current_uiout;
 151 };
 152
 153 /* The main UI.  This is the UI that is bound to stdin/stdout/stderr.
 154    It always exists and is created automatically when GDB starts
 155    up.  */
 156 extern struct ui *main_ui;
 157
 158 /* The current UI.  */
 159 extern struct ui *current_ui;
 160
 161 /* The list of all UIs.  */
 162 extern struct ui *ui_list;
 163
 164 /* State for SWITCH_THRU_ALL_UIS.  */
 165 class switch_thru_all_uis
 166 {
 167 public:
 168
 169   switch_thru_all_uis () : m_iter (ui_list), m_save_ui (&current_ui)
 170   {
 171     current_ui = ui_list;
 172   }
 173
 174   DISABLE_COPY_AND_ASSIGN (switch_thru_all_uis);
 175
 176   /* If done iterating, return true; otherwise return false.  */
 177   bool done () const
 178   {
 179     return m_iter == NULL;
 180   }
 181
 182   /* Move to the next UI, setting current_ui if iteration is not yet
 183      complete.  */
 184   void next ()
 185   {
 186     m_iter = m_iter->next;
 187     if (m_iter != NULL)
 188       current_ui = m_iter;
 189   }
 190
 191  private:
 192
 193   /* Used to iterate through the UIs.  */
 194   struct ui *m_iter;
 195
 196   /* Save and restore current_ui.  */
 197   scoped_restore_tmpl<struct ui *> m_save_ui;
 198 };
 199
 200   /* Traverse through all UI, and switch the current UI to the one
 201      being iterated.  */
 202 #define SWITCH_THRU_ALL_UIS()           \
 203   for (switch_thru_all_uis stau_state; !stau_state.done (); stau_state.next ())
 204
 205 using ui_range = next_range<ui>;
 206
 207 /* An adapter that can be used to traverse over all UIs.  */
 208 static inline
 209 ui_range all_uis ()
 210 {
 211   return ui_range (ui_list);
 212 }
 213
 214 /* Register the UI's input file descriptor in the event loop.  */
 215 extern void ui_register_input_event_handler (struct ui *ui);
 216
 217 /* Unregister the UI's input file descriptor from the event loop.  */
 218 extern void ui_unregister_input_event_handler (struct ui *ui);
 219
 220 /* From top.c.  */
 221 extern bool confirm;
 222 extern int inhibit_gdbinit;
 223
 224 /* Print the GDB version banner to STREAM.  If INTERACTIVE is false,
 225    then information referring to commands (e.g., "show configuration")
 226    is omitted; this mode is used for the --version command line
 227    option.  If INTERACTIVE is true, then interactive commands are
 228    mentioned.  */
 229 extern void print_gdb_version (struct ui_file *stream, bool interactive);
 230
 231 extern void print_gdb_configuration (struct ui_file *);
 232
 233 extern void read_command_file (FILE *);
 234 extern void init_history (void);
 235 extern void command_loop (void);
 236 extern int quit_confirm (void);
 237 extern void quit_force (int *, int);
 238 extern void quit_command (const char *, int);
 239 extern void quit_cover (void);
 240 extern void execute_command (const char *, int);
 241
 242 /* If the interpreter is in sync mode (we're running a user command's
 243    list, running command hooks or similars), and we just ran a
 244    synchronous command that started the target, wait for that command
 245    to end.  WAS_SYNC indicates whether sync_execution was set before
 246    the command was run.  */
 247
 248 extern void maybe_wait_sync_command_done (int was_sync);
 249
 250 /* Wait for a synchronous execution command to end.  */
 251 extern void wait_sync_command_done (void);
 252
 253 extern void check_frame_language_change (void);
 254
 255 /* Prepare for execution of a command.
 256    Call this before every command, CLI or MI.
 257    Returns a cleanup to be run after the command is completed.  */
 258 extern scoped_value_mark prepare_execute_command (void);
 259
 260 /* This function returns a pointer to the string that is used
 261    by gdb for its command prompt.  */
 262 extern const std::string &get_prompt ();
 263
 264 /* This function returns a pointer to the string that is used
 265    by gdb for its command prompt.  */
 266 extern void set_prompt (const char *s);
 267
 268 /* Return 1 if UI's current input handler is a secondary prompt, 0
 269    otherwise.  */
 270
 271 extern int gdb_in_secondary_prompt_p (struct ui *ui);
 272
 273 /* Perform _initialize initialization.  */
 274 extern void gdb_init ();
 275
 276 /* For use by event-top.c.  */
 277 /* Variables from top.c.  */
 278 extern int source_line_number;
 279 extern std::string source_file_name;
 280 extern bool history_expansion_p;
 281 extern bool server_command;
 282 extern char *lim_at_start;
 283
 284 extern void gdb_add_history (const char *);
 285
 286 extern void show_commands (const char *args, int from_tty);
 287
 288 extern void set_verbose (const char *, int, struct cmd_list_element *);
 289
 290 extern char *handle_line_of_input (struct buffer *cmd_line_buffer,
 291                                    const char *rl, int repeat,
 292                                    const char *annotation_suffix);
 293
 294 /* Call at startup to see if the user has requested that gdb start up
 295    quietly.  */
 296
 297 extern bool check_quiet_mode ();
 298
 299 #endif