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, 287 deletions

diff --git a/readline/INSTALL b/readline/INSTALL
deleted file mode 100644
index afb4d53..0000000
--- a/readline/INSTALL
+++ /dev/null
@@ -1,287 +0,0 @@
-Basic Installation
-==================
-
-These are installation instructions for Readline-8.0.
-
-The simplest way to compile readline is:
-
-  1. `cd' to the directory containing the readline source code and type
-     `./configure' to configure readline for your system.  If you're
-     using `csh' on an old version of System V, you might need to type
-     `sh ./configure' instead to prevent `csh' from trying to execute
-     `configure' itself.
-
-     Running `configure' takes some time.  While running, it prints some
-     messages telling which features it is checking for.
-
-  2. Type `make' to compile readline and build the static readline
-     and history libraries.  If supported, the shared readline and history
-     libraries will be built also.  See below for instructions on compiling
-     the other parts of the distribution.  Typing `make everything' will
-     cause the static and shared libraries (if supported) and the example
-     programs to be built.
-
-  3. Type `make install' to install the static readline and history
-     libraries, the readline include files, the documentation, and, if
-     supported, the shared readline and history libraries.
-
-  4. You can remove the created libraries and object files from the
-     build directory by typing `make clean'.  To also remove the
-     files that `configure' created (so you can compile readline for
-     a different kind of computer), type `make distclean'.  There is
-     also a `make maintainer-clean' target, but that is intended mainly
-     for the readline developers, and should be used with care.
-
-The `configure' shell script attempts to guess correct values for
-various system-dependent variables used during compilation.  It
-uses those values to create a `Makefile' in the build directory,
-and Makefiles in the `doc', `shlib', and `examples'
-subdirectories.  It also creates a `config.h' file containing
-system-dependent definitions.  Finally, it creates a shell script
-`config.status' that you can run in the future to recreate the
-current configuration, a file `config.cache' that saves the
-results of its tests to speed up reconfiguring, and a file
-`config.log' containing compiler output (useful mainly for
-debugging `configure'). 
-
-If you need to do unusual things to compile readline, please try
-to figure out how `configure' could check whether to do them, and
-mail diffs or instructions to <bug-readline@gnu.org> so they can
-be considered for the next release.  If at some point
-`config.cache' contains results you don't want to keep, you may
-remove or edit it. 
-
-The file `configure.in' is used to create `configure' by a
-program called `autoconf'.  You only need `configure.in' if you
-want to change it or regenerate `configure' using a newer version
-of `autoconf'.  The readline `configure.in' requires autoconf
-version 2.50 or newer. 
-
-Compilers and Options
-=====================
-
-Some systems require unusual options for compilation or linking that
-the `configure' script does not know about.  You can give `configure'
-initial values for variables by setting them in the environment.  Using
-a Bourne-compatible shell, you can do that on the command line like
-this:
-
-     CC=c89 CFLAGS=-O2 LIBS=-lposix ./configure
-
-Or on systems that have the `env' program, you can do it like this:
-
-     env CPPFLAGS=-I/usr/local/include LDFLAGS=-s ./configure
-
-Compiling For Multiple Architectures
-====================================
-
-You can compile readline for more than one kind of computer at the
-same time, by placing the object files for each architecture in their
-own directory.  To do this, you must use a version of `make' that
-supports the `VPATH' variable, such as GNU `make'.  `cd' to the
-directory where you want the object files and executables to go and run
-the `configure' script.  `configure' automatically checks for the
-source code in the directory that `configure' is in and in `..'.
-
-If you have to use a `make' that does not supports the `VPATH'
-variable, you have to compile readline for one architecture at a
-time in the source code directory.  After you have installed
-readline for one architecture, use `make distclean' before
-reconfiguring for another architecture. 
-
-Installation Names
-==================
-
-By default, `make install' will install the readline libraries in
-`/usr/local/lib', the include files in
-`/usr/local/include/readline', the man pages in `/usr/local/man',
-and the info files in `/usr/local/info'.  You can specify an
-installation prefix other than `/usr/local' by giving `configure'
-the option `--prefix=PATH' or by supplying a value for the
-DESTDIR variable when running `make install'. 
-
-You can specify separate installation prefixes for
-architecture-specific files and architecture-independent files. 
-If you give `configure' the option `--exec-prefix=PATH', the
-readline Makefiles will use PATH as the prefix for installing the
-libraries.  Documentation and other data files will still use the
-regular prefix. 
-
-Specifying the System Type
-==========================
-
-There may be some features `configure' can not figure out
-automatically, but need to determine by the type of host readline
-will run on.  Usually `configure' can figure that out, but if it
-prints a message saying it can not guess the host type, give it
-the `--host=TYPE' option.  TYPE can either be a short name for
-the system type, such as `sun4', or a canonical name with three
-fields: CPU-COMPANY-SYSTEM (e.g., i386-unknown-freebsd4.2). 
-
-See the file `config.sub' for the possible values of each field.
-
-Sharing Defaults
-================
-
-If you want to set default values for `configure' scripts to share,
-you can create a site shell script called `config.site' that gives
-default values for variables like `CC', `cache_file', and `prefix'.
-`configure' looks for `PREFIX/share/config.site' if it exists, then
-`PREFIX/etc/config.site' if it exists.  Or, you can set the
-`CONFIG_SITE' environment variable to the location of the site script.
-A warning: the readline `configure' looks for a site script, but not
-all `configure' scripts do.
-
-Operation Controls
-==================
-
-`configure' recognizes the following options to control how it
-operates.
-
-`--cache-file=FILE'
-     Use and save the results of the tests in FILE instead of
-     `./config.cache'.  Set FILE to `/dev/null' to disable caching, for
-     debugging `configure'.
-
-`--help'
-     Print a summary of the options to `configure', and exit.
-
-`--quiet'
-`--silent'
-`-q'
-     Do not print messages saying which checks are being made.
-
-`--srcdir=DIR'
-     Look for the package's source code in directory DIR.  Usually
-     `configure' can determine that directory automatically.
-
-`--version'
-     Print the version of Autoconf used to generate the `configure'
-     script, and exit.
-
-`configure' also accepts some other, not widely useful, options.
-
-Optional Features
-=================
-
-The readline `configure' recognizes a single `--with-PACKAGE' option:
-
-`--with-curses'
-    This tells readline that it can find the termcap library functions
-    (tgetent, et al.) in the curses library, rather than a separate
-    termcap library.  Readline uses the termcap functions, but does not
-    link with the termcap or curses library itself, allowing applications
-    which link with readline the to choose an appropriate library.
-    This option tells readline to link the example programs with the
-    curses library rather than libtermcap.
-
-`configure' also recognizes two `--enable-FEATURE' options:
-
-`--enable-shared'
-    Build the shared libraries by default on supported platforms.  The
-    default is `yes'.
-
-`--enable-static'
-    Build the static libraries by default.  The default is `yes'.
- 
-Shared Libraries
-================
-
-There is support for building shared versions of the readline and
-history libraries.  The configure script creates a Makefile in
-the `shlib' subdirectory, and typing `make shared' will cause
-shared versions of the readline and history libraries to be built
-on supported platforms.
-
-If `configure' is given the `--enable-shared' option, it will attempt
-to build the shared libraries by default on supported platforms.
-
-Configure calls the script support/shobj-conf to test whether or
-not shared library creation is supported and to generate the values
-of variables that are substituted into shlib/Makefile.  If you
-try to build shared libraries on an unsupported platform, `make'
-will display a message asking you to update support/shobj-conf for
-your platform.
-
-If you need to update support/shobj-conf, you will need to create
-a `stanza' for your operating system and compiler.  The script uses
-the value of host_os and ${CC} as determined by configure.  For
-instance, FreeBSD 4.2 with any version of gcc is identified as
-`freebsd4.2-gcc*'.
-
-In the stanza for your operating system-compiler pair, you will need to
-define several variables.  They are:
-
-SHOBJ_CC	The C compiler used to compile source files into shareable
-		object files.  This is normally set to the value of ${CC}
-		by configure, and should not need to be changed.
-
-SHOBJ_CFLAGS	Flags to pass to the C compiler ($SHOBJ_CC) to create
-		position-independent code.  If you are using gcc, this
-		should probably be set to `-fpic'.
-
-SHOBJ_LD	The link editor to be used to create the shared library from
-		the object files created by $SHOBJ_CC.  If you are using
-		gcc, a value of `gcc' will probably work.
-
-SHOBJ_LDFLAGS	Flags to pass to SHOBJ_LD to enable shared object creation.
-		If you are using gcc, `-shared' may be all that is necessary.
-		These should be the flags needed for generic shared object
-		creation.
-
-SHLIB_XLDFLAGS	Additional flags to pass to SHOBJ_LD for shared library
-		creation.  Many systems use the -R option to the link
-		editor to embed a path within the library for run-time
-		library searches.  A reasonable value for such systems would
-		be `-R$(libdir)'.
-
-SHLIB_LIBS	Any additional libraries that shared libraries should be
-		linked against when they are created.
-
-SHLIB_LIBPREF	The prefix to use when generating the filename of the shared
-		library.  The default is `lib'; Cygwin uses `cyg'.
-
-SHLIB_LIBSUFF	The suffix to add to `libreadline' and `libhistory' when
-		generating the filename of the shared library.  Many systems
-		use `so'; HP-UX uses `sl'.
-
-SHLIB_LIBVERSION The string to append to the filename to indicate the version
-		of the shared library.  It should begin with $(SHLIB_LIBSUFF),
-		and possibly include version information that allows the
-		run-time loader to load the version of the shared library
-		appropriate for a particular program.  Systems using shared
-		libraries similar to SunOS 4.x use major and minor library
-		version numbers; for those systems a value of
-		`$(SHLIB_LIBSUFF).$(SHLIB_MAJOR)$(SHLIB_MINOR)' is appropriate.
-		Systems based on System V Release 4 don't use minor version
-		numbers; use `$(SHLIB_LIBSUFF).$(SHLIB_MAJOR)' on those systems.
-		Other Unix versions use different schemes.
-
-SHLIB_DLLVERSION The version number for shared libraries that determines API
-		compatibility between readline versions and the underlying
-		system.  Used only on Cygwin.  Defaults to $SHLIB_MAJOR, but
-		can be overridden at configuration time by defining DLLVERSION
-		in the environment.
-
-SHLIB_DOT	The character used to separate the name of the shared library
-		from the suffix and version information.  The default is `.';
-		systems like Cygwin which don't separate version information
-		from the library name should set this to the empty string.
-
-SHLIB_STATUS	Set this to `supported' when you have defined the other
-		necessary variables.  Make uses this to determine whether
-		or not shared library creation should be attempted.  If
-		shared libraries are not supported, this will be set to
-		`unsupported'.
-
-You should look at the existing stanzas in support/shobj-conf for ideas.
-
-Once you have updated support/shobj-conf, re-run configure and type
-`make shared' or `make'.  The shared libraries will be created in the
-shlib subdirectory.
-
-If shared libraries are created, `make install' will install them. 
-You may install only the shared libraries by running `make
-install-shared' from the top-level build directory.  Running `make
-install' in the shlib subdirectory will also work.  If you don't want
-to install any created shared libraries, run `make install-static'.