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, 374 deletions

diff --git a/readline/examples/rl-fgets.c b/readline/examples/rl-fgets.c
deleted file mode 100644
index 5512b94..0000000
--- a/readline/examples/rl-fgets.c
+++ /dev/null
@@ -1,374 +0,0 @@
-/*
-Date: Tue, 16 Mar 2004 19:38:40 -0800
-From: Harold Levy <Harold.Levy@synopsys.com>
-Subject: fgets(stdin) --> readline() redirector
-To: chet@po.cwru.edu
-
-Hi Chet,
-
-Here is something you may find useful enough to include in the readline
-distribution.  It is a shared library that redirects calls to fgets(stdin)
-to readline() via LD_PRELOAD, and it supports a custom prompt and list of
-command names.  Many people have asked me for this file, so I thought I'd
-pass it your way in hope of just including it with readline to begin with.
-
-Best Regards,
-
--Harold
-*/
-
-/******************************************************************************
-*******************************************************************************
-  
-  FILE NAME:    fgets.c                  TARGET:   libfgets.so
-  AUTHOR:       Harold Levy              VERSION:  1.0
-                hlevy@synopsys.com
-  
-  ABSTRACT:  Customize fgets() behavior via LD_PRELOAD in the following ways:
-  
-    -- If fgets(stdin) is called, redirect to GNU readline() to obtain
-       command-line editing, file-name completion, history, etc.
-  
-    -- A list of commands for command-name completion can be configured by
-       setting the environment-variable FGETS_COMMAND_FILE to a file containing
-       the list of commands to be used.
-  
-    -- Command-line editing with readline() works best when the prompt string
-       is known; you can set this with the FGETS_PROMPT environment variable.
-  
-    -- There special strings that libfgets will interpret as internal commands:
-  
-           _fgets_reset_    reset the command list
-  
-           _fgets_dump_     dump status
-  
-           _fgets_debug_    toggle debug messages
-
-  HOW TO BUILD:  Here are examples of how to build libfgets.so on various
-  platforms; you will have to add -I and -L flags to configure access to
-  the readline header and library files.
-
-  (32-bit builds with gcc)
-  AIX:   gcc -fPIC fgets.c -shared -o libfgets.so -lc -ldl -lreadline -ltermcap
-  HP-UX: gcc -fPIC fgets.c -shared -o libfgets.so -lc -ldld -lreadline
-  Linux: gcc -fPIC fgets.c -shared -o libfgets.so -lc -ldl -lreadline
-  SunOS: gcc -fPIC fgets.c -shared -o libfgets.so -lc -ldl -lgen -lreadline
-
-  (64-bit builds without gcc)
-  SunOS: SUNWspro/bin/cc -D_LARGEFILE64_SOURCE=1 -xtarget=ultra -xarch=v9 \
-           -KPIC fgets.c -Bdynamic -lc -ldl -lgen -ltermcap -lreadline
-  
-  HOW TO USE:  Different operating systems have different levels of support
-  for the LD_PRELOAD concept.  The generic method for 32-bit platforms is to
-  put libtermcap.so, libfgets.so, and libreadline.so (with absolute paths)
-  in the LD_PRELOAD environment variable, and to put their parent directories
-  in the LD_LIBRARY_PATH environment variable.  Unfortunately there is no
-  generic method for 64-bit platforms; e.g. for 64-bit SunOS, you would have
-  to build both 32-bit and 64-bit libfgets and libreadline libraries, and
-  use the LD_FLAGS_32 and LD_FLAGS_64 environment variables with preload and
-  library_path configurations (a mix of 32-bit and 64-bit calls are made under
-  64-bit SunOS).
-  
-  EXAMPLE WRAPPER:  Here is an example shell script wrapper around the
-  program "foo" that uses fgets() for command-line input:
-
-      #!/bin/csh
-      #### replace this with the libtermcap.so directory:
-      set dir1 = "/usr/lib"
-      #### replace this with the libfgets.so directory:
-      set dir2 = "/usr/fgets"
-      #### replace this with the libreadline.so directory:
-      set dir3 = "/usr/local/lib"
-      set lib1 = "${dir1}/libtermcap.so"
-      set lib2 = "${dir2}/libfgets.so"
-      set lib3 = "${dir3}/libreadline.so"
-      if ( "${?LD_PRELOAD}" ) then
-        setenv LD_PRELOAD "${lib1}:${lib2}:${lib3}:${LD_PRELOAD}"
-      else
-        setenv LD_PRELOAD "${lib1}:${lib2}:${lib3}"
-      endif
-      if ( "${?LD_LIBRARY_PATH}" ) then
-        setenv LD_LIBRARY_PATH "${dir1}:${dir2}:${dir3}:${LD_LIBRARY_PATH}"
-      else
-        setenv LD_LIBRARY_PATH "${dir1}:${dir2}:${dir3}"
-      endif
-      setenv FGETS_COMMAND_FILE "${dir2}/foo.commands"
-      setenv FGETS_PROMPT       "foo> "
-      exec "foo" $*
-  
-  Copyright (C)©2003-2004 Harold Levy.
-  
-  This code links to the GNU readline library, and as such is bound by the
-  terms of the GNU General Public License as published by the Free Software
-  Foundation, either version 2 or (at your option) any later version.
-  
-  The GNU General Public License is often shipped with GNU software, and is
-  generally kept in a file called COPYING or LICENSE.  If you do not have a
-  copy of the license, write to the Free Software Foundation, 59 Temple Place,
-  Suite 330, Boston, MA 02111 USA.
-  
-  This program 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.
-  
-*******************************************************************************
-******************************************************************************/
-
-
-
-#include <dlfcn.h>
-#include <stdio.h>
-#include <strings.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-#include <readline/readline.h>
-#include <readline/history.h>
-
-
-
-/* for dynamically connecting to the native fgets() */
-#if defined(RTLD_NEXT)
-#define REAL_LIBC RTLD_NEXT
-#else
-#define REAL_LIBC ((void *) -1L)
-#endif
-typedef char * ( * fgets_t ) ( char * s, int n, FILE * stream ) ;
-
-
-
-/* private data */
-/* -- writeable data is stored in the shared library's data segment
-   -- every process that uses the shared library gets a private memory copy of
-      its entire data segment
-   -- static data in the shared library is not copied to the application
-   -- only read-only (i.e. 'const') data is stored in the shared library's
-      text segment
-*/
-static char ** my_fgets_names           = NULL ;
-static int     my_fgets_number_of_names = 0    ;
-static int     my_fgets_debug_flag      = 0    ;
-
-
-
-/* invoked with _fgets_reset_ */
-static void
-my_fgets_reset (
-  void
-) {
-  if ( my_fgets_names && (my_fgets_number_of_names > 0) ) {
-    int i ;
-    if ( my_fgets_debug_flag ) {
-      printf ( "libfgets:  removing command list\n" ) ;
-    }
-    for ( i = 0 ; i < my_fgets_number_of_names ; i ++ ) {
-      if ( my_fgets_names[i] ) free ( my_fgets_names[i] ) ;
-    }
-    free ( my_fgets_names ) ;
-  }
-  my_fgets_names = NULL ;
-  my_fgets_number_of_names = 0 ;
-}
-
-
-
-/* invoked with _fgets_dump_ */
-static void
-my_fgets_dump (
-  void
-) {
-  char * s ;
-  printf ( "\n" ) ;
-  s = getenv ( "FGETS_PROMPT" ) ;
-  printf ( "FGETS_PROMPT       = %s\n", s ? s : "" ) ;
-  s = getenv ( "FGETS_COMMAND_FILE" ) ;
-  printf ( "FGETS_COMMAND_FILE = %s\n", s ? s : "" ) ;
-  printf ( "debug flag         = %d\n", my_fgets_debug_flag ) ;
-  printf ( "#commands          = %d\n", my_fgets_number_of_names ) ;
-  if ( my_fgets_debug_flag ) {
-    if ( my_fgets_names && (my_fgets_number_of_names > 0) ) {
-      int i ;
-      for ( i = 0 ; i < my_fgets_number_of_names ; i ++ ) {
-        printf ( "%s\n", my_fgets_names[i] ) ;
-      }
-    }
-  }
-  printf ( "\n" ) ;
-}
-
-
-
-/* invoked with _fgets_debug_ */
-static void
-my_fgets_debug_toggle (
-  void
-) {
-  my_fgets_debug_flag = my_fgets_debug_flag ? 0 : 1 ;
-  if ( my_fgets_debug_flag ) {
-    printf ( "libfgets:  debug flag = %d\n", my_fgets_debug_flag ) ;
-  }
-}
-
-
-
-/* read the command list if needed, return the i-th name */
-static char *
-my_fgets_lookup (
-  int index
-) {
-  if ( (! my_fgets_names) || (! my_fgets_number_of_names) ) {
-    char * fname ;
-    FILE * fp ;
-    fgets_t _fgets ;
-    int i ;
-    char buf1[256], buf2[256] ;
-    fname = getenv ( "FGETS_COMMAND_FILE" ) ;
-    if ( ! fname ) {
-      if ( my_fgets_debug_flag ) {
-        printf ( "libfgets:  empty or unset FGETS_COMMAND_FILE\n" ) ;
-      }
-      return NULL ;
-    }
-    fp = fopen ( fname, "r" ) ;
-    if ( ! fp ) {
-      if ( my_fgets_debug_flag ) {
-        printf ( "libfgets:  cannot open '%s' for reading\n", fname ) ;
-      }
-      return NULL ;
-    }
-    _fgets = (fgets_t) dlsym ( REAL_LIBC, "fgets" ) ;
-    if ( ! _fgets ) {
-      fprintf ( stderr,
-        "libfgets:  failed to dynamically link to native fgets()\n"
-      ) ;
-      return NULL ;
-    }
-    for ( i = 0 ; _fgets(buf1,255,fp) ; i ++ ) ;
-    if ( ! i ) { fclose(fp) ; return NULL ; }
-    my_fgets_names = (char**) calloc ( i, sizeof(char*) ) ;
-    rewind ( fp ) ;
-    i = 0 ;
-    while ( _fgets(buf1,255,fp) ) {
-      buf1[255] = 0 ;
-      if ( 1 == sscanf(buf1,"%s",buf2) ) {
-        my_fgets_names[i] = strdup(buf2) ;
-        i ++ ;
-      }
-    }
-    fclose ( fp ) ;
-    my_fgets_number_of_names = i ;
-    if ( my_fgets_debug_flag ) {
-      printf ( "libfgets:  successfully read %d commands\n", i ) ;
-    }
-  }
-  if ( index < my_fgets_number_of_names ) {
-    return my_fgets_names[index] ;
-  } else {
-    return NULL ;
-  }
-}
-
-
-
-/* generate a list of partial name matches for readline() */
-static char *
-my_fgets_generator (
-  const char * text,
-  int          state
-)
-{
-  static int list_index, len ;
-  char *     name ;
-  if ( ! state ) {
-    list_index = 0 ;
-    len = strlen ( text ) ;
-  }
-  while ( ( name = my_fgets_lookup(list_index) ) ) {
-    list_index ++ ;
-    if ( ! strncmp ( name, text, len ) ) {
-      return ( strdup ( name ) ) ;
-    }
-  }
-  return ( NULL ) ;
-}
-
-
-
-/* partial name completion callback for readline() */
-static char **
-my_fgets_completion (
-  const char * text,
-  int          start,
-  int          end
-)
-{
-  char ** matches ;
-  matches = NULL ;
-  if ( ! start ) {
-    matches = rl_completion_matches ( text, my_fgets_generator ) ;
-  }
-  return ( matches ) ;
-}
-
-
-
-/* fgets() intercept */
-char *
-fgets (
-  char * s,
-  int    n,
-  FILE * stream
-)
-{
-  if ( ! s ) return NULL ;
-  if ( stream == stdin ) {
-    char * prompt ;
-    char * my_fgets_line ;
-    rl_already_prompted = 1 ;
-    rl_attempted_completion_function = my_fgets_completion ;
-    rl_catch_signals = 1 ;
-    rl_catch_sigwinch = 1 ;
-    rl_set_signals () ;
-    prompt = getenv ( "FGETS_PROMPT" ) ;
-    for (
-      my_fgets_line = 0 ; ! my_fgets_line ; my_fgets_line=readline(prompt)
-    ) ;
-    if ( ! strncmp(my_fgets_line, "_fgets_reset_", 13) ) {
-      my_fgets_reset () ;
-      free ( my_fgets_line ) ;
-      strcpy ( s, "\n" ) ;
-      return ( s ) ;
-    }
-    if ( ! strncmp(my_fgets_line, "_fgets_dump_", 12) ) {
-      my_fgets_dump () ;
-      free ( my_fgets_line ) ;
-      strcpy ( s, "\n" ) ;
-      return ( s ) ;
-    }
-    if ( ! strncmp(my_fgets_line, "_fgets_debug_", 13) ) {
-      my_fgets_debug_toggle () ;
-      free ( my_fgets_line ) ;
-      strcpy ( s, "\n" ) ;
-      return ( s ) ;
-    }
-    (void) strncpy ( s, my_fgets_line, n-1 ) ;
-    (void) strcat ( s, "\n" ) ;
-    if ( *my_fgets_line ) add_history ( my_fgets_line ) ;
-    free ( my_fgets_line ) ;
-    return ( s ) ;
-  } else {
-    static fgets_t _fgets ;
-    _fgets = (fgets_t) dlsym ( REAL_LIBC, "fgets" ) ;
-    if ( ! _fgets ) {
-      fprintf ( stderr,
-        "libfgets:  failed to dynamically link to native fgets()\n"
-      ) ;
-      strcpy ( s, "\n" ) ;
-      return ( s ) ;
-    }
-    return (
-      _fgets ( s, n, stream )
-    ) ;
-  }
-}