Move readline to the readline/readline subdirectory

readline turns out to be a bit of a stumbling block for the project to
move gdbsupport (and then gdbserver) to the top-level.

The issue is that readline headers are intended to be included with
names like "readline/readline.h".  To support this, gdb effectively
adds a -I option pointing to the top-level source directory -- but,
importantly, this option is not used when the system readline is used.

For gdbsupport, a -I option like this would always be needed, but that
in turn would break the system readline case.  This was PR build/17077,
fixed in commit a8a5dbcab8df0b3a9e04745d4fe8d64740acb323.

Previously, we had discussed this on the gdb-patches list in terms of
removing readline from the tree

    https://sourceware.org/ml/gdb-patches/2019-09/msg00317.html

However, Eli expressed some concerns, and Joel did as well (off-list).

Given those concerns, and the fact that a patch-free local readline is
relatively new in gdb (it was locally patched for years), I changed my
mind and decided to handle this situation by moving the readline
sources down a level.

That is, upstream readline is now in readline/readline, and the
top-level readline directory just contains the minimal configury
needed to build that.

This fixes the problem because, when gdb unconditionally adds a
-I$(top_srcdir), this will not find readline headers.  A separate -I
will be needed instead, which is exactly what's needed for
--with-system-readline.

gdb/ChangeLog
2019-10-23  Tom Tromey  <tom@tromey.com>

	* Makefile.in (READLINE_DIR): Update.

gdb/doc/ChangeLog
2019-10-23  Tom Tromey  <tom@tromey.com>

	* Makefile.in (READLINE_DIR): Update.

readline/ChangeLog
2019-10-23  Tom Tromey  <tom@tromey.com>

	Move old contents to readline/ subdirectory.
	* aclocal.m4, configure, configure.ac, .gitignore, Makefile.am,
	Makefile.in, README: New files.

Change-Id: Ice156a2ee09ea68722b48f64d97146d7428ea9e4

1 files changed, 0 insertions, 658 deletions

diff --git a/readline/search.c b/readline/search.c
deleted file mode 100644
index c9c1f5d..0000000
--- a/readline/search.c
+++ /dev/null
@@ -1,658 +0,0 @@
-/* search.c - code for non-incremental searching in emacs and vi modes. */
-
-/* Copyright (C) 1992-2017 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>
-#include <stdio.h>
-
-#if defined (HAVE_UNISTD_H)
-#  include <unistd.h>
-#endif
-
-#if defined (HAVE_STDLIB_H)
-#  include <stdlib.h>
-#else
-#  include "ansi_stdlib.h"
-#endif
-
-#include "rldefs.h"
-#include "rlmbutil.h"
-
-#include "readline.h"
-#include "history.h"
-#include "histlib.h"
-
-#include "rlprivate.h"
-#include "xmalloc.h"
-
-#ifdef abs
-#  undef abs
-#endif
-#define abs(x)		(((x) >= 0) ? (x) : -(x))
-
-_rl_search_cxt *_rl_nscxt = 0;
-
-extern HIST_ENTRY *_rl_saved_line_for_history;
-
-/* Functions imported from the rest of the library. */
-extern void _rl_free_history_entry PARAMS((HIST_ENTRY *));
-
-static char *noninc_search_string = (char *) NULL;
-static int noninc_history_pos;
-
-static char *prev_line_found = (char *) NULL;
-
-static int rl_history_search_len;
-static int rl_history_search_pos;
-static int rl_history_search_flags;
-
-static char *history_search_string;
-static int history_string_size;
-
-static void make_history_line_current PARAMS((HIST_ENTRY *));
-static int noninc_search_from_pos PARAMS((char *, int, int, int, int *));
-static int noninc_dosearch PARAMS((char *, int, int));
-static int noninc_search PARAMS((int, int));
-static int rl_history_search_internal PARAMS((int, int));
-static void rl_history_search_reinit PARAMS((int));
-
-static _rl_search_cxt *_rl_nsearch_init PARAMS((int, int));
-static void _rl_nsearch_abort PARAMS((_rl_search_cxt *));
-static int _rl_nsearch_dispatch PARAMS((_rl_search_cxt *, int));
-
-/* Make the data from the history entry ENTRY be the contents of the
-   current line.  This doesn't do anything with rl_point; the caller
-   must set it. */
-static void
-make_history_line_current (HIST_ENTRY *entry)
-{
-  _rl_replace_text (entry->line, 0, rl_end);
-  _rl_fix_point (1);
-#if defined (VI_MODE)
-  if (rl_editing_mode == vi_mode)
-    /* POSIX.2 says that the `U' command doesn't affect the copy of any
-       command lines to the edit line.  We're going to implement that by
-       making the undo list start after the matching line is copied to the
-       current editing buffer. */
-    rl_free_undo_list ();
-#endif
-
-  if (_rl_saved_line_for_history)
-    _rl_free_history_entry (_rl_saved_line_for_history);
-  _rl_saved_line_for_history = (HIST_ENTRY *)NULL;
-}
-
-/* Search the history list for STRING starting at absolute history position
-   POS.  If STRING begins with `^', the search must match STRING at the
-   beginning of a history line, otherwise a full substring match is performed
-   for STRING.  DIR < 0 means to search backwards through the history list,
-   DIR >= 0 means to search forward. */
-static int
-noninc_search_from_pos (char *string, int pos, int dir, int flags, int *ncp)
-{
-  int ret, old, sflags;
-  char *s;
-
-  if (pos < 0)
-    return -1;
-
-  old = where_history ();
-  if (history_set_pos (pos) == 0)
-    return -1;
-
-  RL_SETSTATE(RL_STATE_SEARCH);
-  /* These functions return the match offset in the line; history_offset gives
-     the matching line in the history list */
-  if (flags & SF_PATTERN)
-    {
-      s = string;
-      sflags = 0;		/* Non-anchored search */
-      if (*s == '^')
-	{
-	  sflags |= ANCHORED_SEARCH;
-	  s++;
-	}
-      ret = _hs_history_patsearch (s, dir, sflags);
-    }
-  else if (*string == '^')
-    ret = history_search_prefix (string + 1, dir);
-  else
-    ret = history_search (string, dir);
-  RL_UNSETSTATE(RL_STATE_SEARCH);
-
-  if (ncp)
-    *ncp = ret;		/* caller will catch -1 to indicate no-op */
-
-  if (ret != -1)
-    ret = where_history ();
-
-  history_set_pos (old);
-  return (ret);
-}
-
-/* Search for a line in the history containing STRING.  If DIR is < 0, the
-   search is backwards through previous entries, else through subsequent
-   entries.  Returns 1 if the search was successful, 0 otherwise. */
-static int
-noninc_dosearch (char *string, int dir, int flags)
-{
-  int oldpos, pos;
-  HIST_ENTRY *entry;
-
-  if (string == 0 || *string == '\0' || noninc_history_pos < 0)
-    {
-      rl_ding ();
-      return 0;
-    }
-
-  pos = noninc_search_from_pos (string, noninc_history_pos + dir, dir, flags, (int *)0);
-  if (pos == -1)
-    {
-      /* Search failed, current history position unchanged. */
-      rl_maybe_unsave_line ();
-      rl_clear_message ();
-      rl_point = 0;
-      rl_ding ();
-      return 0;
-    }
-
-  noninc_history_pos = pos;
-
-  oldpos = where_history ();
-  history_set_pos (noninc_history_pos);
-  entry = current_history ();		/* will never be NULL after successful search */
-  
-#if defined (VI_MODE)
-  if (rl_editing_mode != vi_mode)
-#endif
-    history_set_pos (oldpos);
-
-  make_history_line_current (entry);
-
-  rl_point = 0;
-  rl_mark = rl_end;
-
-  rl_clear_message ();
-  return 1;
-}
-
-static _rl_search_cxt *
-_rl_nsearch_init (int dir, int pchar)
-{
-  _rl_search_cxt *cxt;
-  char *p;
-
-  cxt = _rl_scxt_alloc (RL_SEARCH_NSEARCH, 0);
-  if (dir < 0)
-    cxt->sflags |= SF_REVERSE;		/* not strictly needed */
-#if defined (VI_MODE)
-  if (VI_COMMAND_MODE() && (pchar == '?' || pchar == '/'))
-    cxt->sflags |= SF_PATTERN;
-#endif
-
-  cxt->direction = dir;
-  cxt->history_pos = cxt->save_line;
-
-  rl_maybe_save_line ();
-
-  /* Clear the undo list, since reading the search string should create its
-     own undo list, and the whole list will end up being freed when we
-     finish reading the search string. */
-  rl_undo_list = 0;
-
-  /* Use the line buffer to read the search string. */
-  rl_line_buffer[0] = 0;
-  rl_end = rl_point = 0;
-
-  p = _rl_make_prompt_for_search (pchar ? pchar : ':');
-  rl_message ("%s", p);
-  xfree (p);
-
-  RL_SETSTATE(RL_STATE_NSEARCH);
-
-  _rl_nscxt = cxt;
-
-  return cxt;
-}
-
-int
-_rl_nsearch_cleanup (_rl_search_cxt *cxt, int r)
-{
-  _rl_scxt_dispose (cxt, 0);
-  _rl_nscxt = 0;
-
-  RL_UNSETSTATE(RL_STATE_NSEARCH);
-
-  return (r != 1);
-}
-
-static void
-_rl_nsearch_abort (_rl_search_cxt *cxt)
-{
-  rl_maybe_unsave_line ();
-  rl_clear_message ();
-  rl_point = cxt->save_point;
-  rl_mark = cxt->save_mark;
-  rl_restore_prompt ();
-
-  RL_UNSETSTATE (RL_STATE_NSEARCH);
-}
-
-/* Process just-read character C according to search context CXT.  Return -1
-   if the caller should abort the search, 0 if we should break out of the
-   loop, and 1 if we should continue to read characters. */
-static int
-_rl_nsearch_dispatch (_rl_search_cxt *cxt, int c)
-{
-  if (c < 0)
-    c = CTRL ('C');  
-
-  switch (c)
-    {
-    case CTRL('W'):
-      rl_unix_word_rubout (1, c);
-      break;
-
-    case CTRL('U'):
-      rl_unix_line_discard (1, c);
-      break;
-
-    case RETURN:
-    case NEWLINE:
-      return 0;
-
-    case CTRL('H'):
-    case RUBOUT:
-      if (rl_point == 0)
-	{
-	  _rl_nsearch_abort (cxt);
-	  return -1;
-	}
-      _rl_rubout_char (1, c);
-      break;
-
-    case CTRL('C'):
-    case CTRL('G'):
-      rl_ding ();
-      _rl_nsearch_abort (cxt);
-      return -1;
-
-    default:
-#if defined (HANDLE_MULTIBYTE)
-      if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
-	rl_insert_text (cxt->mb);
-      else
-#endif
-	_rl_insert_char (1, c);
-      break;
-    }
-
-  (*rl_redisplay_function) ();
-  return 1;
-}
-
-/* Perform one search according to CXT, using NONINC_SEARCH_STRING.  Return
-   -1 if the search should be aborted, any other value means to clean up
-   using _rl_nsearch_cleanup ().  Returns 1 if the search was successful,
-   0 otherwise. */
-static int
-_rl_nsearch_dosearch (_rl_search_cxt *cxt)
-{
-  rl_mark = cxt->save_mark;
-
-  /* If rl_point == 0, we want to re-use the previous search string and
-     start from the saved history position.  If there's no previous search
-     string, punt. */
-  if (rl_point == 0)
-    {
-      if (noninc_search_string == 0)
-	{
-	  rl_ding ();
-	  rl_restore_prompt ();
-	  RL_UNSETSTATE (RL_STATE_NSEARCH);
-	  return -1;
-	}
-    }
-  else
-    {
-      /* We want to start the search from the current history position. */
-      noninc_history_pos = cxt->save_line;
-      FREE (noninc_search_string);
-      noninc_search_string = savestring (rl_line_buffer);
-
-      /* If we don't want the subsequent undo list generated by the search
-	 matching a history line to include the contents of the search string,
-	 we need to clear rl_line_buffer here.  For now, we just clear the
-	 undo list generated by reading the search string.  (If the search
-	 fails, the old undo list will be restored by rl_maybe_unsave_line.) */
-      rl_free_undo_list ();
-    }
-
-  rl_restore_prompt ();
-  return (noninc_dosearch (noninc_search_string, cxt->direction, cxt->sflags&SF_PATTERN));
-}
-
-/* Search non-interactively through the history list.  DIR < 0 means to
-   search backwards through the history of previous commands; otherwise
-   the search is for commands subsequent to the current position in the
-   history list.  PCHAR is the character to use for prompting when reading
-   the search string; if not specified (0), it defaults to `:'. */
-static int
-noninc_search (int dir, int pchar)
-{
-  _rl_search_cxt *cxt;
-  int c, r;
-
-  cxt = _rl_nsearch_init (dir, pchar);
-
-  if (RL_ISSTATE (RL_STATE_CALLBACK))
-    return (0);
-
-  /* Read the search string. */
-  r = 0;
-  while (1)
-    {
-      c = _rl_search_getchar (cxt);
-
-      if (c < 0)
-	{
-	  _rl_nsearch_abort (cxt);
-	  return 1;
-	}
-	  
-      if (c == 0)
-	break;
-
-      r = _rl_nsearch_dispatch (cxt, c);
-      if (r < 0)
-        return 1;
-      else if (r == 0)
-	break;        
-    }
-
-  r = _rl_nsearch_dosearch (cxt);
-  return ((r >= 0) ? _rl_nsearch_cleanup (cxt, r) : (r != 1));
-}
-
-/* Search forward through the history list for a string.  If the vi-mode
-   code calls this, KEY will be `?'. */
-int
-rl_noninc_forward_search (int count, int key)
-{
-  return noninc_search (1, (key == '?') ? '?' : 0);
-}
-
-/* Reverse search the history list for a string.  If the vi-mode code
-   calls this, KEY will be `/'. */
-int
-rl_noninc_reverse_search (int count, int key)
-{
-  return noninc_search (-1, (key == '/') ? '/' : 0);
-}
-
-/* Search forward through the history list for the last string searched
-   for.  If there is no saved search string, abort.  If the vi-mode code
-   calls this, KEY will be `N'. */
-int
-rl_noninc_forward_search_again (int count, int key)
-{
-  int r;
-
-  if (!noninc_search_string)
-    {
-      rl_ding ();
-      return (1);
-    }
-#if defined (VI_MODE)
-  if (VI_COMMAND_MODE() && key == 'N')
-    r = noninc_dosearch (noninc_search_string, 1, SF_PATTERN);
-  else
-#endif
-    r = noninc_dosearch (noninc_search_string, 1, 0);
-  return (r != 1);
-}
-
-/* Reverse search in the history list for the last string searched
-   for.  If there is no saved search string, abort.  If the vi-mode code
-   calls this, KEY will be `n'. */
-int
-rl_noninc_reverse_search_again (int count, int key)
-{
-  int r;
-
-  if (!noninc_search_string)
-    {
-      rl_ding ();
-      return (1);
-    }
-#if defined (VI_MODE)
-  if (VI_COMMAND_MODE() && key == 'n')
-    r = noninc_dosearch (noninc_search_string, -1, SF_PATTERN);
-  else
-#endif
-    r = noninc_dosearch (noninc_search_string, -1, 0);
-  return (r != 1);
-}
-
-#if defined (READLINE_CALLBACKS)
-int
-_rl_nsearch_callback (_rl_search_cxt *cxt)
-{
-  int c, r;
-
-  c = _rl_search_getchar (cxt);
-  if (c <= 0)
-    {
-      if (c < 0)
-        _rl_nsearch_abort (cxt);
-      return 1;
-    }
-  r = _rl_nsearch_dispatch (cxt, c);
-  if (r != 0)
-    return 1;
-
-  r = _rl_nsearch_dosearch (cxt);
-  return ((r >= 0) ? _rl_nsearch_cleanup (cxt, r) : (r != 1));
-}
-#endif
-  
-static int
-rl_history_search_internal (int count, int dir)
-{
-  HIST_ENTRY *temp;
-  int ret, oldpos, newcol;
-  char *t;
-
-  rl_maybe_save_line ();
-  temp = (HIST_ENTRY *)NULL;
-
-  /* Search COUNT times through the history for a line matching
-     history_search_string.  If history_search_string[0] == '^', the
-     line must match from the start; otherwise any substring can match.
-     When this loop finishes, TEMP, if non-null, is the history line to
-     copy into the line buffer. */
-  while (count)
-    {
-      RL_CHECK_SIGNALS ();
-      ret = noninc_search_from_pos (history_search_string, rl_history_search_pos + dir, dir, 0, &newcol);
-      if (ret == -1)
-	break;
-
-      /* Get the history entry we found. */
-      rl_history_search_pos = ret;
-      oldpos = where_history ();
-      history_set_pos (rl_history_search_pos);
-      temp = current_history ();	/* will never be NULL after successful search */
-      history_set_pos (oldpos);
-
-      /* Don't find multiple instances of the same line. */
-      if (prev_line_found && STREQ (prev_line_found, temp->line))
-        continue;
-      prev_line_found = temp->line;
-      count--;
-    }
-
-  /* If we didn't find anything at all, return. */
-  if (temp == 0)
-    {
-      rl_maybe_unsave_line ();
-      rl_ding ();
-      /* If you don't want the saved history line (last match) to show up
-         in the line buffer after the search fails, change the #if 0 to
-         #if 1 */
-#if 0
-      if (rl_point > rl_history_search_len)
-        {
-          rl_point = rl_end = rl_history_search_len;
-          rl_line_buffer[rl_end] = '\0';
-          rl_mark = 0;
-        }
-#else
-      rl_point = rl_history_search_len;	/* rl_maybe_unsave_line changes it */
-      rl_mark = rl_end;
-#endif
-      return 1;
-    }
-
-  /* Copy the line we found into the current line buffer. */
-  make_history_line_current (temp);
-
-  /* decide where to put rl_point -- need to change this for pattern search */
-  if (rl_history_search_flags & ANCHORED_SEARCH)
-    rl_point = rl_history_search_len;	/* easy case */
-  else
-    {
-#if 0
-      t = strstr (rl_line_buffer, history_search_string);	/* XXX */
-      rl_point = t ? (int)(t - rl_line_buffer) + rl_history_search_len : rl_end;
-#else
-      rl_point = (newcol >= 0) ? newcol : rl_end;
-#endif
-    }
-  rl_mark = rl_end;
-
-  return 0;
-}
-
-static void
-rl_history_search_reinit (int flags)
-{
-  int sind;
-
-  rl_history_search_pos = where_history ();
-  rl_history_search_len = rl_point;
-  rl_history_search_flags = flags;
-
-  prev_line_found = (char *)NULL;
-  if (rl_point)
-    {
-      /* Allocate enough space for anchored and non-anchored searches */
-      if (rl_history_search_len >= history_string_size - 2)
-	{
-	  history_string_size = rl_history_search_len + 2;
-	  history_search_string = (char *)xrealloc (history_search_string, history_string_size);
-	}
-      sind = 0;
-      if (flags & ANCHORED_SEARCH)
-	history_search_string[sind++] = '^';
-      strncpy (history_search_string + sind, rl_line_buffer, rl_point);
-      history_search_string[rl_point + sind] = '\0';
-    }
-  _rl_free_saved_history_line ();
-}
-
-/* Search forward in the history for the string of characters
-   from the start of the line to rl_point.  This is a non-incremental
-   search.  The search is anchored to the beginning of the history line. */
-int
-rl_history_search_forward (int count, int ignore)
-{
-  if (count == 0)
-    return (0);
-
-  if (rl_last_func != rl_history_search_forward &&
-      rl_last_func != rl_history_search_backward)
-    rl_history_search_reinit (ANCHORED_SEARCH);
-
-  if (rl_history_search_len == 0)
-    return (rl_get_next_history (count, ignore));
-  return (rl_history_search_internal (abs (count), (count > 0) ? 1 : -1));
-}
-
-/* Search backward through the history for the string of characters
-   from the start of the line to rl_point.  This is a non-incremental
-   search. */
-int
-rl_history_search_backward (int count, int ignore)
-{
-  if (count == 0)
-    return (0);
-
-  if (rl_last_func != rl_history_search_forward &&
-      rl_last_func != rl_history_search_backward)
-    rl_history_search_reinit (ANCHORED_SEARCH);
-
-  if (rl_history_search_len == 0)
-    return (rl_get_previous_history (count, ignore));
-  return (rl_history_search_internal (abs (count), (count > 0) ? -1 : 1));
-}
-
-/* Search forward in the history for the string of characters
-   from the start of the line to rl_point.  This is a non-incremental
-   search.  The search succeeds if the search string is present anywhere
-   in the history line. */
-int
-rl_history_substr_search_forward (int count, int ignore)
-{
-  if (count == 0)
-    return (0);
-
-  if (rl_last_func != rl_history_substr_search_forward &&
-      rl_last_func != rl_history_substr_search_backward)
-    rl_history_search_reinit (NON_ANCHORED_SEARCH);
-
-  if (rl_history_search_len == 0)
-    return (rl_get_next_history (count, ignore));
-  return (rl_history_search_internal (abs (count), (count > 0) ? 1 : -1));
-}
-
-/* Search backward through the history for the string of characters
-   from the start of the line to rl_point.  This is a non-incremental
-   search. */
-int
-rl_history_substr_search_backward (int count, int ignore)
-{
-  if (count == 0)
-    return (0);
-
-  if (rl_last_func != rl_history_substr_search_forward &&
-      rl_last_func != rl_history_substr_search_backward)
-    rl_history_search_reinit (NON_ANCHORED_SEARCH);
-
-  if (rl_history_search_len == 0)
-    return (rl_get_previous_history (count, ignore));
-  return (rl_history_search_internal (abs (count), (count > 0) ? -1 : 1));
-}