Tcl Mac OS X README
-------------------

This is the README file for the Mac OS X/Darwin version of Tcl.


1. Where to go for support
--------------------------

- The tcl-mac mailing list on sourceforge is the best place to ask questions
specific to Tcl & Tk on Mac OS X:
	http://lists.sourceforge.net/lists/listinfo/tcl-mac
(this page also has a link to searchable archives of the list, please check them
before asking on the list, many questions have already been answered).

- For general Tcl/Tk questions, the newsgroup comp.lang.tcl is your best bet:
	http://groups.google.com/group/comp.lang.tcl/

- The Tcl'ers Wiki also has many pages dealing with Tcl & Tk on Mac OS X, see
	http://wiki.tcl.tk/_/ref?N=3753
	http://wiki.tcl.tk/_/ref?N=8361

- Please report bugs with Tcl or Tk on Mac OS X to the sourceforge bug trackers:
	http://tcl.sourceforge.net/

2. Using Tcl on Mac OS X
------------------------

- At a minimum, Mac OS X 10.3 is required to run Tcl.

- Unless weak-linking is used, Tcl built on Mac OS X 10.x will not run on 10.y
with y < x; on the other hand Tcl built on 10.y will always run on 10.x with
y <= x (but without any of the fixes and optimizations that would be available
in a binary built on 10.x).
Weak-linking is available on OS X 10.2 or later, it additionally allows Tcl
built on 10.x to run on any 10.y with x > y >= z (for a chosen z >= 2).

- Tcl extensions can be installed in any of:
	$HOME/Library/Tcl /Library/Tcl /System/Library/Tcl
	$HOME/Library/Frameworks /Library/Frameworks /System/Library/Frameworks
	(searched in that order).
Given a potential package directory $pkg, Tcl on OSX checks for the file
$pkg/Resources/Scripts/pkgIndex.tcl as well as the usual $pkg/pkgIndex.tcl.
This allows building extensions as frameworks with all script files contained in
the Resources/Scripts directory of the framework.

- [load]able binary extensions can linked as either ordinary shared libraries
(.dylib) or as MachO bundles (since 8.4.10/8.5a3); bundles have the advantage
that they are [load]ed more efficiently from a tcl VFS (no temporary copy to the
native filesystem required), and prior to Mac OS X 10.5, only bundles can be
[unload]ed.

- The 'deploy' target of macosx/GNUmakefile installs the html manpages into the
standard documentation location in the Tcl framework:
	Tcl.framework/Resources/Documentation/Reference/Tcl
No nroff manpages are installed by default by the GNUmakefile.

- The Tcl framework can be installed in any of the system's standard
framework directories:
	$HOME/Library/Frameworks /Library/Frameworks /System/Library/Frameworks


3. Building Tcl on Mac OS X
---------------------------

- At least Mac OS X 10.3 is required to build Tcl.
Apple's Xcode Developer Tools need to be installed (only the most recent version
matching your OS release is supported), the Xcode installer is available on Mac
OS X install media or may be present in /Applications/Installers on Macs that
came with OS X preinstalled. The most recent version can always be downloaded
from the ADC website http://connect.apple.com (free ADC membership required).

- Tcl is most easily built as a Mac OS X framework via GNUmakefile in tcl/macosx
(see below for details), but can also be built with the standard unix configure
and make buildsystem in tcl/unix as on any other unix platform (indeed, the
GNUmakefile is just a wrapper around the unix buildsystem).
The Mac OS X specific configure flags are --enable-framework and
--disable-corefoundation (which disables CF and notably reverts to the standard
select based notifier).

- It is also possible to build with the Xcode IDE via the projects in
tcl/macosx, take care to use the project matching your DevTools and OS version:
	Tcl.xcode: 		    for Xcode 3.1 on 10.5
	Tcl.xcodeproj:		    for Xcode 3.2 on 10.6
These have the following targets:
	Tcl:			    calls through to tcl/macosx/GNUMakefile.
	tcltest:		    static build of tcltest for debugging.
	tests:			    build tcltest target and run tcl testsuite.
The following build configurations are available:
	Debug:			    debug build for the active architecture,
				    with Fix & Continue enabled.
	Debug clang:		    use clang compiler.
	Debug llvm-gcc:		    use llvm-gcc compiler.
	Debug gcc40:		    use gcc 4.0 compiler.
	DebugNoFixAndContinue:      disable Fix & Continue.
	DebugUnthreaded:	    disable threading.
	DebugNoCF:		    disable corefoundation.
	DebugNoCFUnthreaded:	    disable corefoundation an threading.
	DebugMemCompile:	    enable memory and bytecode debugging.
	DebugLeaks:		    define PURIFY.
	DebugGCov:		    enable generation of gcov data files.
	Debug64bit:		    configure with --enable-64bit (requires
				    building on a 64bit capable processor).
	Release:		    release build for the active architecture.
	ReleaseUniversal:	    32/64-bit universal build.
	ReleaseUniversal clang:	    use clang compiler.
	ReleaseUniversal llvm-gcc:  use llvm-gcc compiler.
	ReleaseUniversal gcc40:	    use gcc 4.0 compiler.
	ReleaseUniversal10.5SDK:    build against the 10.5 SDK (with 10.5
				    deployment target).
	Note that the non-SDK configurations have their deployment target set to
	10.5 (Tcl.xcode) resp. 10.6 (Tcl.xcodeproj).
The Xcode projects refer to the toplevel tcl source directory via the
TCL_SRCROOT user build setting, by default this is set to the project-relative
path '../../tcl', if your tcl source directory is named differently, e.g.
'../../tcl8.6', you need to manually change the TCL_SRCROOT setting by editing
your ${USER}.pbxuser file (located inside the Tcl.xcodeproj bundle directory)
with a text editor.

- To build universal binaries outside of the Xcode IDE, set CFLAGS as follows:
	export CFLAGS="-arch i386 -arch x86_64 -arch ppc"
This requires Mac OS X 10.4 and Xcode 2.4 (or Xcode 2.2 if -arch x86_64 is
omitted, but _not_ Xcode 2.1) and will work on any architecture (on PowerPC
Tiger you need to add "-isysroot /Developer/SDKs/MacOSX10.4u.sdk").
Note that configure requires CFLAGS to contain a least one architecture that can
be run on the build machine (i.e. ppc on G3/G4, ppc or ppc64 on G5, ppc or i386
on Core and ppc, i386 or x86_64 on Core2/Xeon).
Universal builds of Tcl TEA extensions are also possible with CFLAGS set as
above, they will be [load]able by universal as well as thin binaries of Tcl.

- To enable weak-linking, set the MACOSX_DEPLOYMENT_TARGET environment variable
to the minimal OS version the binaries should be able to run on, e.g:
	export MACOSX_DEPLOYMENT_TARGET=10.4
This requires at least gcc 3.1; with gcc 4 or later, set/add to CFLAGS instead:
	export CFLAGS="-mmacosx-version-min=10.4"
Support for weak-linking was added with 8.4.14/8.5a5.

Detailed Instructions for building with macosx/GNUmakefile
----------------------------------------------------------

- Unpack the Tcl source release archive.

- The following instructions assume the Tcl source tree is named "tcl${ver}",
(where ${ver} is a shell variable containing the Tcl version number e.g. '8.6').
Setup this shell variable as follows:
	ver="8.6"
If you are building from CVS, omit this step (CVS source tree names usually do
not contain a version number).

- Setup environment variables as desired, e.g. for a universal build on 10.5:
	CFLAGS="-arch i386 -arch x86_64 -arch ppc -mmacosx-version-min=10.5"
	export CFLAGS

- Change to the directory containing the Tcl source tree and build:
	make -C tcl${ver}/macosx

- Install Tcl onto the root volume (admin password required):
	sudo make -C tcl${ver}/macosx install
if you don't have an admin password, you can install into your home directory
instead by passing an INSTALL_ROOT argument to make:
	make -C tcl${ver}/macosx install INSTALL_ROOT="${HOME}/"

- The default GNUmakefile targets will build _both_ debug and optimized versions
of the Tcl framework with the standard convention of naming the debug library
Tcl.framework/Tcl_debug.
This allows switching to the debug libraries at runtime by setting
	export DYLD_IMAGE_SUFFIX=_debug
(c.f. man dyld for more details)

If you only want to build and install the debug or optimized build, use the
'develop' or 'deploy' target variants of the GNUmakefile, respectively.
For example, to build and install only the optimized versions:
	make -C tcl${ver}/macosx deploy
	sudo make -C tcl${ver}/macosx install-deploy
