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   bool m_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   /* Register the UI's input file descriptor in the event loop.  */
 153   void register_file_handler ();
 154
 155   /* Unregister the UI's input file descriptor from the event loop.  */
 156   void unregister_file_handler ();
 157
 158   /* Return true if this UI's input fd is a tty.  */
 159   bool input_interactive_p () const;
 160 };
 161
 162 /* The main UI.  This is the UI that is bound to stdin/stdout/stderr.
 163    It always exists and is created automatically when GDB starts
 164    up.  */
 165 extern struct ui *main_ui;
 166
 167 /* The current UI.  */
 168 extern struct ui *current_ui;
 169
 170 /* The list of all UIs.  */
 171 extern struct ui *ui_list;
 172
 173 /* State for SWITCH_THRU_ALL_UIS.  */
 174 class switch_thru_all_uis
 175 {
 176 public:
 177
 178   switch_thru_all_uis () : m_iter (ui_list), m_save_ui (&current_ui)
 179   {
 180     current_ui = ui_list;
 181   }
 182
 183   DISABLE_COPY_AND_ASSIGN (switch_thru_all_uis);
 184
 185   /* If done iterating, return true; otherwise return false.  */
 186   bool done () const
 187   {
 188     return m_iter == NULL;
 189   }
 190
 191   /* Move to the next UI, setting current_ui if iteration is not yet
 192      complete.  */
 193   void next ()
 194   {
 195     m_iter = m_iter->next;
 196     if (m_iter != NULL)
 197       current_ui = m_iter;
 198   }
 199
 200  private:
 201
 202   /* Used to iterate through the UIs.  */
 203   struct ui *m_iter;
 204
 205   /* Save and restore current_ui.  */
 206   scoped_restore_tmpl<struct ui *> m_save_ui;
 207 };
 208
 209   /* Traverse through all UI, and switch the current UI to the one
 210      being iterated.  */
 211 #define SWITCH_THRU_ALL_UIS()           \
 212   for (switch_thru_all_uis stau_state; !stau_state.done (); stau_state.next ())
 213
 214 using ui_range = next_range<ui>;
 215
 216 /* An adapter that can be used to traverse over all UIs.  */
 217 static inline
 218 ui_range all_uis ()
 219 {
 220   return ui_range (ui_list);
 221 }
 222
 223 /* From top.c.  */
 224 extern bool confirm;
 225 extern int inhibit_gdbinit;
 226
 227 /* Print the GDB version banner to STREAM.  If INTERACTIVE is false,
 228    then information referring to commands (e.g., "show configuration")
 229    is omitted; this mode is used for the --version command line
 230    option.  If INTERACTIVE is true, then interactive commands are
 231    mentioned.  */
 232 extern void print_gdb_version (struct ui_file *stream, bool interactive);
 233
 234 extern void print_gdb_configuration (struct ui_file *);
 235
 236 extern void read_command_file (FILE *);
 237 extern void init_history (void);
 238 extern void command_loop (void);
 239 extern int quit_confirm (void);
 240 extern void quit_force (int *, int);
 241 extern void quit_command (const char *, int);
 242 extern void quit_cover (void);
 243 extern void execute_command (const char *, int);
 244
 245 /* If the interpreter is in sync mode (we're running a user command's
 246    list, running command hooks or similars), and we just ran a
 247    synchronous command that started the target, wait for that command
 248    to end.  WAS_SYNC indicates whether sync_execution was set before
 249    the command was run.  */
 250
 251 extern void maybe_wait_sync_command_done (int was_sync);
 252
 253 /* Wait for a synchronous execution command to end.  */
 254 extern void wait_sync_command_done (void);
 255
 256 extern void check_frame_language_change (void);
 257
 258 /* Prepare for execution of a command.
 259    Call this before every command, CLI or MI.
 260    Returns a cleanup to be run after the command is completed.  */
 261 extern scoped_value_mark prepare_execute_command (void);
 262
 263 /* This function returns a pointer to the string that is used
 264    by gdb for its command prompt.  */
 265 extern const std::string &get_prompt ();
 266
 267 /* This function returns a pointer to the string that is used
 268    by gdb for its command prompt.  */
 269 extern void set_prompt (const char *s);
 270
 271 /* Return 1 if UI's current input handler is a secondary prompt, 0
 272    otherwise.  */
 273
 274 extern int gdb_in_secondary_prompt_p (struct ui *ui);
 275
 276 /* Perform _initialize initialization.  */
 277 extern void gdb_init ();
 278
 279 /* For use by event-top.c.  */
 280 /* Variables from top.c.  */
 281 extern int source_line_number;
 282 extern std::string source_file_name;
 283 extern bool history_expansion_p;
 284 extern bool server_command;
 285 extern char *lim_at_start;
 286
 287 extern void gdb_add_history (const char *);
 288
 289 extern void show_commands (const char *args, int from_tty);
 290
 291 extern void set_verbose (const char *, int, struct cmd_list_element *);
 292
 293 extern char *handle_line_of_input (struct buffer *cmd_line_buffer,
 294                                    const char *rl, int repeat,
 295                                    const char *annotation_suffix);
 296
 297 /* Call at startup to see if the user has requested that gdb start up
 298    quietly.  */
 299
 300 extern bool check_quiet_mode ();
 301
 302 #endif