README at [75999463a7]

File README artifact f55796d36b part of check-in 75999463a7


This will build a Tclkit named "tclkit-<version>" or a KitDLL named
"libtclkit<version>.so".

---------------
Using This Tool
---------------
Usage:
	kitcreator [{<version> | cvs_<cvsTag> | clean | distclean}]
	           [<configure_options...>]

	Where:
		version            is a Tcl version number (e.g., 8.4.19)
		cvsTag             is a CVS release tag (e.g., HEAD)
		configure_options  are options to pass to subordinate configure
		                   scripts (e.g., --enable-64bit)

	Default is to create a Tclkit from Tcl version 8.4.19

Examples:
	1. Create a Tclkit:
		a. $ ./kitcreator

	2. Create a Tclkit for Tcl 8.5.8:
		a. $ ./kitcreator 8.5.8

	3. Create a Tclkit for Tcl from CVS HEAD:
		a. $ ./kitcreator cvs_HEAD

	4. Compile a 64-bit Tclkit:
		a. $ ./kitcreator --enable-64bit

	5. Cross-compile a Tclkit:
		a. Bootstrap (optional, you can use an existing Tclkit):
			i.   $ ./kitcreator
			ii.  $ mv tclkit-8.4.19 tclkit-local
			iii. $ TCLKIT="`pwd`/tclkit-local"
			iv.  $ export TCLKIT
		b. Cross-compile:
			i.   $ CC=mipsel-linux-uclibc-gcc
			ii.  $ CXX=false
			iii. $ AR=mipsel-linux-uclibc-ar
			iv.  $ RANLIB=mipsel-linux-uclibc-ranlib
			v.   $ export CC CXX AR RANLIB
		v.   $ ./kitcreator --host=mipsel-linux-uclibc

	6. Compile a 64-bit Tclkit 8.5.8 using SunStudio 12.1 on Solaris/x86:
		a. $ CC='/opt/sunstudio12.1/bin/cc -m64'
		b. $ CXX='/opt/sunstudio12.1/bin/CC -m64'
		c. $ PATCH='gpatch'
		c. $ export CC CXX PATCH
		d. $ ./kitcreator 8.5.8 --enable-64bit

	7. To clean up post-build:
		a. $ ./kitcreator clean

	8. Create a Tclkit without Metakit4 support (falls back to Zip for storage):
		a. KITCREATOR_PKGS='tk itcl'
		b. export KITCREATOR_PKGS
		c. ./kitcreator

	9. Create a Tclkit with Metakit4 support, but using Zip for storage:
		a. $ ./kitcreator --enable-kit-storage=zip

	10. Create a Tclkit with Metakit4 support, but using C-VFS for storage
		a. $ ./kitcreator --enable-kit-storage=cvfs

	11. Create a KitDLL without Metakit support (will not create a Tclkit
	    binary, just the library):
		a. $ KITCREATOR_PKGS='tk itcl kitdll'
		b. $ export KITCREATOR_PKGS
		c. $ ./kitcreator

Environment variables:
	1. MAKE
		Specifies the tool you wish to be called to build targets
		from a Makefile.  This script is generally more well tested
		with GNU Make.

	2. PATCH
		Specifies the tool you wish to be called to apply unified
		diff patches.  This script is generally more well tested with
		GNU Patch. 

	3. TCLKIT
		Specify the path to a Tclkit that is runnable on the current
		system.  The default is "tclkit".  A working tclkit is required
		for cross-compiling Tclkits.

	4. STATICTK
		Specify this as "1" to statically link to Tk.  The default
		action on most platforms is to dynamically link to Tk.  When
		building KitDLL, STATICTK is "1" by default.  If you want to
		enable dynamic linking of Tk with KitDLL you will have to
		specify this as "-1".

	5. STATICMK4
		Specify this as "0" to attempt to create create the "mk4tcl"
		project as a shared object.  If this fails, it will fall back
		to building statically.  Specify it as "-1" to force building
		it as a shared object.  Any other value, including being unset
		results in "mk4tcl" being built and linked statically.  KitDILL
		sets this to variable to "0".  If Metakit4 is built shared, it
		cannot be used for the kit storage for Tclkit.

	6. STRIP
		Specifies the tool you wish to be called to strip object files,
		archives, and shared objects.  The default is "strip".  You
		should probably set this if you are cross-compiling.

	7. KITCREATOR_PKGS
		Specify which non-required packages to build.  The default list
		is:
			tk itcl mk4tcl

		If mk4tcl is not present a Zip-based storage mechanism will be
		used instead.  To specify that the default be used, do not set
		this or set it to the empty string.  To specify that no
		non-required packages be built, set it to a string that
		contains only white space.

		If "kitdll" is specified in the list the target becomes KitDLL
		and no Tclkit will built, but instead libtclkit.

	8. KITCREATOR_MINENCODINGS
		Set this variable to a non-empty string to generate a Tclkit
		without all encodings, only including the following:
			ascii.enc cp1252.enc iso8859-1.enc iso8859-15.enc
			iso8859-2.enc koi8-r.enc macRoman.enc

	9. KITCREATOR_MINBUILD
		Set this variable to a non-empty string to exclude unnecessary
		packages from Tcl build.  This excludes the following packages:
			tcltest

		Additionally, any bundled packages (in the "pkgs" directory)
		are excluded.  This typically includes (as of Tcl 8.6):
			itcl thread

Kitsh Configure Options:
	1. --enable-kit-storage={zip|mk4|auto}
		Specify which type of storage to use with the Tclkit.  The
		default is to auto-detect.  Auto-detection uses Mk4 if
		available and built statically, otherwise it falls back to Zip.

-------------------
Method of Operation
-------------------
Summary:
	1. "kitcreator" calls */build.sh
	2. */build.sh downloads and compiles appropriate software
	3. */build.sh installs software into "inst" (run-time + compile-time)
	4. */build.sh installs run-time software into "out", this will be
	   included in the Tclkit as if it were the root directory of the
	   Tclkit (combined with other "out" directories)
	5. kitsh/build.sh compiles a "main" function and links all the built
	   libraries together into an executable
	6. kitsh/build.sh combines all the "out" directories into one
	7. kitsh/build.sh creates a Metakit or Zip database from the combined
	   directories and appends that to the compiled executable using:
		a. A Tclkit found in the environment variable "TCLKIT" (tclkit
		   if unset) if it is functional; or
		b. The built kit itself (does not work for cross-compiling)

Details:
	The general mechanism that enables a Tclkit to operate is a small Tcl
initialization routine linked statically to the core libraries needed to
operate a Tcl interpreter, the Tcl VFS Layer, and a database-backed (Metakit)
Virtual File System that is appended to the end of the executable.

This project brings together all of the required pieces, plus some additional
pieces that were found in the original Tclkit:
	1. Tk (dynamically linked)
	2. Itcl (dynamically linked)

The source code for these pieces are downloaded, compiled, and linked, and the
database containing the appropriate filesystem data is created.  What sets
this project apart from other similar projects is that:
	1. It attempts to be modular;
	2. It supports cross-compiling;
	3. It downloads the source from their original repositories;
	4. It allows you to specify an arbitrary version of Tcl (including
	   CVS); and
	5. It uses GNU Autoconf scripts for compiling the part of the Tclkit
	   that brings the whole thing together (the Kitsh)

To accomplish these goals the following mechanisms are in place:
	1. The top-level "kitcreator" script; and
	2. Per-project subdirectories, each containing a "build.sh" script

The top-level "kitcreator" script is very simple.  Its only job is to
interpret command line arguments, and call the per-project "build.sh" scripts.
For the "tcl" project it also finds the appropriate "tclConfig.sh" (and stores
this path in TCLCONFIGDIR) to enable subsequent build scripts to find the
appropriate Tcl to link against.

The per-project "build.sh" scripts are entirely autonomous.  They are
responsible for downloading the source code for the appropriate version that
will compile and link against the current version of Tcl (user requested
version can be found in "TCLVERS", while the actual version must be requested
from the "tclConfig.sh" script), compiling it, installing a functional copy
into the per-project "inst" directory, and installing anything that needs to
be in the Tclkit's VFS root into the per-project "out" directory.

The exception to this is the "kitsh" and "kitdll" projects.  They are the glue
that binds all the individual projects together into a single executable.  Its
build script does not create an "inst" or an "out" directory because it is not
a library.  Instead, it collects all the other project's "out" directories
into a single directory (starpack.vfs), as well a static file (boot.tcl).
It then compiles the source code, and then installs the VFS onto the resulting
executable.  The VFS is created by the "installvfs.tcl" script for Kitsh.  For
KitDLL the VFS is created by "dir2c.tcl".

If the "mk4tcl" project fails to build (or is not requested to be built),
the rest of the project will be built using zip files instead of Metakit
databases.

To create the storage database, one of two Tclkits is used (tried in this
order):
	1. The Tclkit specified by the TCLKIT environment variable (or
	   "tclkit" if that variable is not set) if it is functional; or
	2. The built Tclkit itself

The second method will not work if the built Tclkit is not executable on the
current platform (i.e., in the case of cross-compilation) and so it may be
necessary to bootstrap a runnable Tclkit first.

KitDLL mounts the VFS for every interpreter that calls Tcl_Init().  The system
VFS that is created at build time is mounted at /.KITDLL_TCL.  Additionally,
if there is a ZIP file appended to the DLL it will be mounted at /.KITDLL_USER
and if there is a ZIP file appended to the executable it will be mounted at
/.KITDLL_APP.  All VFSes that are mounted have the "lib" sub-directory appended
to the interpreters "auto_path" variable.