readline/readline/undo.c - binutils-gdb - Git at Google

 /* undo.c - manage list of changes to lines, offering opportunity to undo them */

 /* Copyright (C) 1987-2017 Free Software Foundation, Inc.

    This file is part of the GNU Readline Library (Readline), a library
    for reading lines of text with interactive input and history editing.

    Readline is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Readline is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Readline.  If not, see <http://www.gnu.org/licenses/>.
 */

 #define READLINE_LIBRARY

 #if defined (HAVE_CONFIG_H)
 #  include <config.h>
 #endif

 #include <sys/types.h>

 #if defined (HAVE_UNISTD_H)
 #  include <unistd.h>           /* for _POSIX_VERSION */
 #endif /* HAVE_UNISTD_H */

 #if defined (HAVE_STDLIB_H)
 #  include <stdlib.h>
 #else
 #  include "ansi_stdlib.h"
 #endif /* HAVE_STDLIB_H */

 #include <stdio.h>

 /* System-specific feature definitions and include files. */
 #include "rldefs.h"

 /* Some standard library routines. */
 #include "readline.h"
 #include "history.h"

 #include "rlprivate.h"
 #include "xmalloc.h"

 extern void _hs_replace_history_data PARAMS((int, histdata_t *, histdata_t *));

 extern HIST_ENTRY *_rl_saved_line_for_history;

 /* Non-zero tells rl_delete_text and rl_insert_text to not add to
    the undo list. */
 int _rl_doing_an_undo = 0;

 /* How many unclosed undo groups we currently have. */
 int _rl_undo_group_level = 0;

 /* The current undo list for THE_LINE. */
 UNDO_LIST *rl_undo_list = (UNDO_LIST *)NULL;

 /* **************************************************************** */
 /*								    */
 /*			Undo, and Undoing			    */
 /*								    */
 /* **************************************************************** */

 static UNDO_LIST *
 alloc_undo_entry (enum undo_code what, int start, int end, char *text)
 {
   UNDO_LIST *temp;

   temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST));
   temp->what = what;
   temp->start = start;
   temp->end = end;
   temp->text = text;

   temp->next = (UNDO_LIST *)NULL;
   return temp;
 }

 /* Remember how to undo something.  Concatenate some undos if that
    seems right. */
 void
 rl_add_undo (enum undo_code what, int start, int end, char *text)
 {
   UNDO_LIST *temp;

   temp = alloc_undo_entry (what, start, end, text);
   temp->next = rl_undo_list;
   rl_undo_list = temp;
 }

 /* Free an UNDO_LIST */
 void
 _rl_free_undo_list (UNDO_LIST *ul)
 {
   UNDO_LIST *release;

   while (ul)
     {
       release = ul;
       ul = ul->next;

       if (release->what == UNDO_DELETE)
 	xfree (release->text);

       xfree (release);
     }
 }

 /* Free the existing undo list. */
 void
 rl_free_undo_list (void)
 {
   UNDO_LIST *release, *orig_list;

   orig_list = rl_undo_list;
   _rl_free_undo_list (rl_undo_list);
   rl_undo_list = (UNDO_LIST *)NULL;
   _hs_replace_history_data (-1, (histdata_t *)orig_list, (histdata_t *)NULL);
 }

 UNDO_LIST *
 _rl_copy_undo_entry (UNDO_LIST *entry)
 {
   UNDO_LIST *new;

   new = alloc_undo_entry (entry->what, entry->start, entry->end, (char *)NULL);
   new->text = entry->text ? savestring (entry->text) : 0;
   return new;
 }

 UNDO_LIST *
 _rl_copy_undo_list (UNDO_LIST *head)
 {
   UNDO_LIST *list, *new, *roving, *c;

   if (head == 0)
     return head;

   list = head;
   new = 0;
   while (list)
     {
       c = _rl_copy_undo_entry (list);
       if (new == 0)
 	roving = new = c;
       else
 	{
 	  roving->next = c;
 	  roving = roving->next;
 	}
       list = list->next;
     }

   roving->next = 0;
   return new;
 }

 /* Undo the next thing in the list.  Return 0 if there
    is nothing to undo, or non-zero if there was. */
 int
 rl_do_undo (void)
 {
   UNDO_LIST *release, *search;
   int waiting_for_begin, start, end;
   HIST_ENTRY *cur, *temp;

 #define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i)))

   start = end = waiting_for_begin = 0;
   do
     {
       if (rl_undo_list == 0)
 	return (0);

       _rl_doing_an_undo = 1;
       RL_SETSTATE(RL_STATE_UNDOING);

       /* To better support vi-mode, a start or end value of -1 means
 	 rl_point, and a value of -2 means rl_end. */
       if (rl_undo_list->what == UNDO_DELETE || rl_undo_list->what == UNDO_INSERT)
 	{
 	  start = TRANS (rl_undo_list->start);
 	  end = TRANS (rl_undo_list->end);
 	}

       switch (rl_undo_list->what)
 	{
 	/* Undoing deletes means inserting some text. */
 	case UNDO_DELETE:
 	  rl_point = start;
 	  _rl_fix_point (1);
 	  rl_insert_text (rl_undo_list->text);
 	  xfree (rl_undo_list->text);
 	  break;

 	/* Undoing inserts means deleting some text. */
 	case UNDO_INSERT:
 	  rl_delete_text (start, end);
 	  rl_point = start;
 	  _rl_fix_point (1);
 	  break;

 	/* Undoing an END means undoing everything 'til we get to a BEGIN. */
 	case UNDO_END:
 	  waiting_for_begin++;
 	  break;

 	/* Undoing a BEGIN means that we are done with this group. */
 	case UNDO_BEGIN:
 	  if (waiting_for_begin)
 	    waiting_for_begin--;
 	  else
 	    rl_ding ();
 	  break;
 	}

       _rl_doing_an_undo = 0;
       RL_UNSETSTATE(RL_STATE_UNDOING);

       release = rl_undo_list;
       rl_undo_list = rl_undo_list->next;
       release->next = 0;	/* XXX */

       /* If we are editing a history entry, make sure the change is replicated
 	 in the history entry's line */
       cur = current_history ();
       if (cur && cur->data && (UNDO_LIST *)cur->data == release)
 	{
 	  temp = replace_history_entry (where_history (), rl_line_buffer, (histdata_t)rl_undo_list);
 	  xfree (temp->line);
 	  FREE (temp->timestamp);
 	  xfree (temp);
 	}

       /* Make sure there aren't any history entries with that undo list */
       _hs_replace_history_data (-1, (histdata_t *)release, (histdata_t *)rl_undo_list);

       /* And make sure this list isn't anywhere in the saved line for history */
       if (_rl_saved_line_for_history && _rl_saved_line_for_history->data)
 	{
 	  /* Brute force; no finesse here */
 	  search = (UNDO_LIST *)_rl_saved_line_for_history->data;
 	  if (search == release)
 	    _rl_saved_line_for_history->data = rl_undo_list;
 	  else
 	    {
 	      while (search->next)
 		{
 		  if (search->next == release)
 		    {
 		      search->next = rl_undo_list;
 		      break;
 		    }
 		  search = search->next;
 		}
 	    }
 	}

       xfree (release);
     }
   while (waiting_for_begin);

   return (1);
 }
 #undef TRANS

 int
 _rl_fix_last_undo_of_type (int type, int start, int end)
 {
   UNDO_LIST *rl;

   for (rl = rl_undo_list; rl; rl = rl->next)
     {
       if (rl->what == type)
 	{
 	  rl->start = start;
 	  rl->end = end;
 	  return 0;
 	}
     }
   return 1;
 }

 /* Begin a group.  Subsequent undos are undone as an atomic operation. */
 int
 rl_begin_undo_group (void)
 {
   rl_add_undo (UNDO_BEGIN, 0, 0, 0);
   _rl_undo_group_level++;
   return 0;
 }

 /* End an undo group started with rl_begin_undo_group (). */
 int
 rl_end_undo_group (void)
 {
   rl_add_undo (UNDO_END, 0, 0, 0);
   _rl_undo_group_level--;
   return 0;
 }

 /* Save an undo entry for the text from START to END. */
 int
 rl_modifying (int start, int end)
 {
   if (start > end)
     {
       SWAP (start, end);
     }

   if (start != end)
     {
       char *temp = rl_copy_text (start, end);
       rl_begin_undo_group ();
       rl_add_undo (UNDO_DELETE, start, end, temp);
       rl_add_undo (UNDO_INSERT, start, end, (char *)NULL);
       rl_end_undo_group ();
     }
   return 0;
 }

 /* Revert the current line to its previous state. */
 int
 rl_revert_line (int count, int key)
 {
   if (rl_undo_list == 0)
     rl_ding ();
   else
     {
       while (rl_undo_list)
 	rl_do_undo ();
 #if defined (VI_MODE)
       if (rl_editing_mode == vi_mode)
 	rl_point = rl_mark = 0;		/* rl_end should be set correctly */
 #endif
     }

   return 0;
 }

 /* Do some undoing of things that were done. */
 int
 rl_undo_command (int count, int key)
 {
   if (count < 0)
     return 0;	/* Nothing to do. */

   while (count)
     {
       if (rl_do_undo ())
 	count--;
       else
 	{
 	  rl_ding ();
 	  break;
 	}
     }
   return 0;
 }
	/* undo.c - manage list of changes to lines, offering opportunity to undo them */

	/* Copyright (C) 1987-2017 Free Software Foundation, Inc.

	This file is part of the GNU Readline Library (Readline), a library
	for reading lines of text with interactive input and history editing.

	Readline is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	Readline is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with Readline. If not, see <http://www.gnu.org/licenses/>.
	*/

	#define READLINE_LIBRARY

	#if defined (HAVE_CONFIG_H)
	# include <config.h>
	#endif

	#include <sys/types.h>

	#if defined (HAVE_UNISTD_H)
	# include <unistd.h> /* for _POSIX_VERSION */
	#endif /* HAVE_UNISTD_H */

	#if defined (HAVE_STDLIB_H)
	# include <stdlib.h>
	#else
	# include "ansi_stdlib.h"
	#endif /* HAVE_STDLIB_H */

	#include <stdio.h>

	/* System-specific feature definitions and include files. */
	#include "rldefs.h"

	/* Some standard library routines. */
	#include "readline.h"
	#include "history.h"

	#include "rlprivate.h"
	#include "xmalloc.h"

	extern void _hs_replace_history_data PARAMS((int, histdata_t , histdata_t ));

	extern HIST_ENTRY *_rl_saved_line_for_history;

	/* Non-zero tells rl_delete_text and rl_insert_text to not add to
	the undo list. */
	int _rl_doing_an_undo = 0;

	/* How many unclosed undo groups we currently have. */
	int _rl_undo_group_level = 0;

	/* The current undo list for THE_LINE. */
	UNDO_LIST rl_undo_list = (UNDO_LIST )NULL;

	/* **************************************************************** */
	/* */
	/* Undo, and Undoing */
	/* */
	/* **************************************************************** */

	static UNDO_LIST *
	alloc_undo_entry (enum undo_code what, int start, int end, char *text)
	{
	UNDO_LIST *temp;

	temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST));
	temp->what = what;
	temp->start = start;
	temp->end = end;
	temp->text = text;

	temp->next = (UNDO_LIST *)NULL;
	return temp;
	}

	/* Remember how to undo something. Concatenate some undos if that
	seems right. */
	void
	rl_add_undo (enum undo_code what, int start, int end, char *text)
	{
	UNDO_LIST *temp;

	temp = alloc_undo_entry (what, start, end, text);
	temp->next = rl_undo_list;
	rl_undo_list = temp;
	}

	/* Free an UNDO_LIST */
	void
	_rl_free_undo_list (UNDO_LIST *ul)
	{
	UNDO_LIST *release;

	while (ul)
	{
	release = ul;
	ul = ul->next;

	if (release->what == UNDO_DELETE)
	xfree (release->text);

	xfree (release);
	}
	}

	/* Free the existing undo list. */
	void
	rl_free_undo_list (void)
	{
	UNDO_LIST release, orig_list;

	orig_list = rl_undo_list;
	_rl_free_undo_list (rl_undo_list);
	rl_undo_list = (UNDO_LIST *)NULL;
	_hs_replace_history_data (-1, (histdata_t )orig_list, (histdata_t )NULL);
	}

	UNDO_LIST *
	_rl_copy_undo_entry (UNDO_LIST *entry)
	{
	UNDO_LIST *new;

	new = alloc_undo_entry (entry->what, entry->start, entry->end, (char *)NULL);
	new->text = entry->text ? savestring (entry->text) : 0;
	return new;
	}

	UNDO_LIST *
	_rl_copy_undo_list (UNDO_LIST *head)
	{
	UNDO_LIST list, new, roving, c;

	if (head == 0)
	return head;

	list = head;
	new = 0;
	while (list)
	{
	c = _rl_copy_undo_entry (list);
	if (new == 0)
	roving = new = c;
	else
	{
	roving->next = c;
	roving = roving->next;
	}
	list = list->next;
	}

	roving->next = 0;
	return new;
	}

	/* Undo the next thing in the list. Return 0 if there
	is nothing to undo, or non-zero if there was. */
	int
	rl_do_undo (void)
	{
	UNDO_LIST release, search;
	int waiting_for_begin, start, end;
	HIST_ENTRY cur, temp;

	#define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i)))

	start = end = waiting_for_begin = 0;
	do
	{
	if (rl_undo_list == 0)
	return (0);

	_rl_doing_an_undo = 1;
	RL_SETSTATE(RL_STATE_UNDOING);

	/* To better support vi-mode, a start or end value of -1 means
	rl_point, and a value of -2 means rl_end. */
	if (rl_undo_list->what == UNDO_DELETE \|\| rl_undo_list->what == UNDO_INSERT)
	{
	start = TRANS (rl_undo_list->start);
	end = TRANS (rl_undo_list->end);
	}

	switch (rl_undo_list->what)
	{
	/* Undoing deletes means inserting some text. */
	case UNDO_DELETE:
	rl_point = start;
	_rl_fix_point (1);
	rl_insert_text (rl_undo_list->text);
	xfree (rl_undo_list->text);
	break;

	/* Undoing inserts means deleting some text. */
	case UNDO_INSERT:
	rl_delete_text (start, end);
	rl_point = start;
	_rl_fix_point (1);
	break;

	/* Undoing an END means undoing everything 'til we get to a BEGIN. */
	case UNDO_END:
	waiting_for_begin++;
	break;

	/* Undoing a BEGIN means that we are done with this group. */
	case UNDO_BEGIN:
	if (waiting_for_begin)
	waiting_for_begin--;
	else
	rl_ding ();
	break;
	}

	_rl_doing_an_undo = 0;
	RL_UNSETSTATE(RL_STATE_UNDOING);

	release = rl_undo_list;
	rl_undo_list = rl_undo_list->next;
	release->next = 0; /* XXX */

	/* If we are editing a history entry, make sure the change is replicated
	in the history entry's line */
	cur = current_history ();
	if (cur && cur->data && (UNDO_LIST *)cur->data == release)
	{
	temp = replace_history_entry (where_history (), rl_line_buffer, (histdata_t)rl_undo_list);
	xfree (temp->line);
	FREE (temp->timestamp);
	xfree (temp);
	}

	/* Make sure there aren't any history entries with that undo list */
	_hs_replace_history_data (-1, (histdata_t )release, (histdata_t )rl_undo_list);

	/* And make sure this list isn't anywhere in the saved line for history */
	if (_rl_saved_line_for_history && _rl_saved_line_for_history->data)
	{
	/* Brute force; no finesse here */
	search = (UNDO_LIST *)_rl_saved_line_for_history->data;
	if (search == release)
	_rl_saved_line_for_history->data = rl_undo_list;
	else
	{
	while (search->next)
	{
	if (search->next == release)
	{
	search->next = rl_undo_list;
	break;
	}
	search = search->next;
	}
	}
	}

	xfree (release);
	}
	while (waiting_for_begin);

	return (1);
	}
	#undef TRANS

	int
	_rl_fix_last_undo_of_type (int type, int start, int end)
	{
	UNDO_LIST *rl;

	for (rl = rl_undo_list; rl; rl = rl->next)
	{
	if (rl->what == type)
	{
	rl->start = start;
	rl->end = end;
	return 0;
	}
	}
	return 1;
	}

	/* Begin a group. Subsequent undos are undone as an atomic operation. */
	int
	rl_begin_undo_group (void)
	{
	rl_add_undo (UNDO_BEGIN, 0, 0, 0);
	_rl_undo_group_level++;
	return 0;
	}

	/* End an undo group started with rl_begin_undo_group (). */
	int
	rl_end_undo_group (void)
	{
	rl_add_undo (UNDO_END, 0, 0, 0);
	_rl_undo_group_level--;
	return 0;
	}

	/* Save an undo entry for the text from START to END. */
	int
	rl_modifying (int start, int end)
	{
	if (start > end)
	{
	SWAP (start, end);
	}

	if (start != end)
	{
	char *temp = rl_copy_text (start, end);
	rl_begin_undo_group ();
	rl_add_undo (UNDO_DELETE, start, end, temp);
	rl_add_undo (UNDO_INSERT, start, end, (char *)NULL);
	rl_end_undo_group ();
	}
	return 0;
	}

	/* Revert the current line to its previous state. */
	int
	rl_revert_line (int count, int key)
	{
	if (rl_undo_list == 0)
	rl_ding ();
	else
	{
	while (rl_undo_list)
	rl_do_undo ();
	#if defined (VI_MODE)
	if (rl_editing_mode == vi_mode)
	rl_point = rl_mark = 0; /* rl_end should be set correctly */
	#endif
	}

	return 0;
	}

	/* Do some undoing of things that were done. */
	int
	rl_undo_command (int count, int key)
	{
	if (count < 0)
	return 0; /* Nothing to do. */

	while (count)
	{
	if (rl_do_undo ())
	count--;
	else
	{
	rl_ding ();
	break;
	}
	}
	return 0;
	}