wxWidgets/wxPython/BUILD.unix.txt

Building wxPython on Unix or Unix-like Systems
----------------------------------------------

NOTE:  You should probably look at the ../ README.1st.txt file for
directions for how to build wxPython the "new way."  This files
describes the "old way" to build on unix-like systems.  The difference
is very simple:  The new way uses a private copy of wxGTK while the
old way uses either an existing wxGTK that may be installed and used
by other apps, or you can build a wxGTK that will be accissible by
other apps.


NOTE 2: I use a tool called SWIG (http://www.swig.org) to help
generate the C++ sources used in the wxPython extension module.
However you don't need to have SWIG unless you want to modify the *.i
files.  I've made several modifications to and older version of SWIG
that are specific to wxPython's needs and so the modified sources are
included in the wx CVS at .../wxPython/wxSWIG.  But because of the
size and since most people won't need it my SWIG is not included in
the wxPythonSrc tarball.  You'll need to get it from CVS or a CVS
snapshot.

If you need to modify the *.i files for wxPython then you will need to
build wxswig.  Change to the .../wxPython/wxSWIG directory and run:

      configure
      make

(Do not run "make install" as wxswig is run in-place.)  You'll then
need to change a flag in the setup.py script as described below so the
wxPython build process will use SWIG if needed.

I use the new Python Distutils tool to build wxPython.  It is included
with Python 2.0, but if you want to use Python 1.5.2 or 1.6 then
you'll need to download and install Distutils 1.0 from
http://www.python.org/sigs/distutils-sig/

Okay, now on the the fun stuff...


1. Compile and/or install glib and gtk+
---------------------------------------

A. First of all, check and see if you've already got glib/gtk+ on your
   system, all the Linux distributions I know of come with it, at
   least as an option.  Look for libglib.* and libgtk.* in your system's
   standard library directories.  You'll also need the headers and
   config scripts in order to build things that use glib/gtk.  Try
   running gtk-config:

	   gtk-config --version

   If you have version 1.2.7 or better then you're all set.  Otherwise
   either get the pacakges for your unix distribution and install them
   or get the sources from www.gtk.org and build and install them.

   The best version to get is the latest 1.2.x release as the
   wxWindows support for GTK 2.x is still beta-level.  (Most tings
   work great though, and it looks real nice.)



2. Compile and/or install wxGTK
-------------------------------

A. You can find the sources and RPMs for wxGTK at
   http://wxwindows.org/, just follow the download links from the
   navigation panel.

   Source code for wxGTK is now included with the wxPythonSrc tarball,
   and is the recommended way to get released wxGTK source code if you
   plan on building both.

   You can also check out a current snapshot of the sources from the
   CVS server.  (Some information about annonymous CVS access is at
   http://wxwindows.org/cvs.htm.)  The advantage of using CVS is that
   you can easily update as soon as the developers check in new
   sources or fixes.  The advantage of using a released version is
   that it usually has had more thorough testing done.  You can decide
   which method is best for you.


B. You'll usually want to use a version of wxGTK that has the same
   version number as the wxPython sources you are using.  (Another
   advantage of using wxPythonSrc or CVS is that you'll get both at
   the same time.)


C. If using the RPMs be sure to get both the wxGTK and wxGTK-devel
   RPMs (at a minimum) and then install them as root.

	rpm -Uhv wxGTK-2.2.2-0.i386.rpm wxGTK-devel-2.2.2-0.i386.rpm


D. If using the sources (either from the tarball or from CVS) then
   configure it like this:

	cd wxWindows   # or whatever your top-level directory is called
	mkdir build
	cd build
	../configure --with-gtk --enable-geometry

   There are gobs and gobs of options for the configure script, run
   ../configure --help to see them all.  I'll describe some that I find
   useful here.

   If you have OpenGL or compatible libraries installed, then add the
   --with-opengl flag.

   If you are on Solaris and are using a recent version of GCC, then
   you'll probably want to add the --enable-permissive flag so the
   compiler won't barf on your broken X11 header files.

   To make a debugging version of wxGTK, add the --enable-debug flag.
   This sets the -g flag for the compiler and also activates some
   special debugging code in wxWindows by defining the __WXDEBUG__
   macro.  You'll get some extra asserts, failure logging, etc.

   If you are using GTK 2.x then you'll want to add --enable-gtk2 and
   probably also --enable-unicode.


E. Now just compile and install.  You need to use GNU make, so if your
   system has something else get GNU make and build and install it and
   use it instead of your system's default make command.

       make
       make install

   The last step will probably have to be done as root.  Also, if your
   system needs anything done to update the dynamic loader for shared
   libraries, (such as running ldconfig on Linux) then do it now.


F. You can test your build by changing to one of the directories under
   build/samples or build/demos, running make and then running the
   executable that is built.



3. Compile and install wxPython
-------------------------------

A. You have the same options (and same advantages/disadvantages) for
   getting the wxPython source, either a released snapshot or from
   CVS.  The released version file is named wxPythonSrc-[version].tar.gz
   and is available at http://wxpython.org/download.php.  If you want
   to use CVS you'll find wxPython in the wxWindows CVS tree (see
   above) in the wxWindows/wxPython directory.


B. wxPython is built with the standard Python Distutils tool and
   currently includes it's own snapshot of the latest version of
   distutils which can also be used with previous versions of Python

   On Unix systems Distutils figures out what commands and flags to
   use for the compiler and linker by looking in the Makefile that was
   used to build Python itself.  Most of the time this works okay.  If
   it doesn't, there doesn't seem to be a way to override the values
   that Distutils uses without hacking either Distutils itself, or
   Python's Makefile.  (NOTE:  This has been changed with the
   distutilsincluded with Python 2.3 but I havn't yet looked into how
   best to utilize this in wxPython...)

   While we're on the subject of how Python was built... Since
   wxPython is a C++ extension some platforms and/or compilers will
   require that the Python executable was linked with the C++ linker
   in order for everything to work correctly.  If you build and
   install Python yourself then this is easy to take care of,
   otherwise you may have to mess with binary packages or bribe your
   system administrator...

   In my case on Solaris wxPython applications would core dump on
   exit.  The core file indicated that the fault happened after
   _exit() was called and the run-time library was trying to execute
   cleanup code.  After relinking the Python executable the problem
   went away.  To build Python to link with the C++ linker do this:

         cd Python-2.0      # wherever the root of the source tree is
	 rm python          # in case it's still there from an old build
         make LINKCC=g++    # or whatever your C++ command is
	 make install

   I recently built Python 2.1.3 and Python 2.2.1 on Solaris and did
   not have to resort to this workaround so apparently things are
   getting better there.  I will leave this note here though in case
   there are similar issues elsewhere.  However I did run into a
   Python build issue that affects the wxPython build when attempting
   to use SunCC instead of GNU gcc.  See the note below titled
   "Building with non-GNU compilers" if you are interested.


C. Change to the root wxPython directory and look at the setup.py
   file.  This is the script that configures and defines all the
   information that Distutils needs to build wxPython.  There are some
   options near the begining of the script that you may want or need
   to change based on your system and what options you have selected
   up to this point, (sources from tar.gz or from CVS, etc.)  You can
   either change these flags directly in setup.py or supply them on
   the command-line.

	BUILD_GLCANVAS Set to zero if you don't want to build the
		       Open GL canvas extension module.  If you don't
		       have OpenGL or compatible libraries then you'll
		       need to set this to zero.

	     BUILD_OGL Set to zero if you don't want to build the
		       Object Graphics Library extension module.

  	     BUILD_STC Set to zero if you don't want to build the
		       wxStyledTextCtrl (the Scintilla wrapper)
		       extension module.

  	      USE_SWIG If you have edited any of the *.i files you
		       will need to set this flag to non-zero so SWIG
		       will be executed to regenerate the wrapper C++
		       and shadow python files.

		  etc.


D. To build and install wxPython you simply need to execute the
   setup.py script.  If you have more than one version of Python
   installed, be sure to execute setup.py with the version you want to
   build wxPython for.  Depending on the permissions on your
   site-packages directory you may need to be root to run the install
   command.

	 python setup.py build install

   If you need to change any of the build flags that can also be done
   on the setup.py command line, like this:

	 python setup.py BUILD_GLCANVAS=0 build install

   If you are using GTK 2.x then you'll want to add these flags:

         python setup.py WXPORT=gtk2 UNICODE=1 build install

   If you would like to install to someplace besides the Python
   site-packages directory (such as to your home directory) then you
   can add "--root=<path>" after the "install" command.  To use
   wxPython like this you'll need to ensure that the directory
   containing wxPyrthon is contained in in the PYTHONPATH environment
   variable.


E. At this point you should be able to change into the wxPython/demo
   directory and run the demo:

	 python demo.py


F. If you would like to make a test build that doesn't overwrite any
   installed version of wxPython you can do so with this command
   instead of the install command above:

	 python setup.py build_ext --inplace

   This will build the wxPython package in the local wxPython
   directory instead of installing it under your Python installation.
   To run using this test version just add the base wxPython source
   directory to the PYTHONPATH:

         export PYTHONPATH=~/projects/wxWindows/wxPython
	 # or whatever is required for your shell
	 cd ~/projects/wxWindows/wxPython/demo
	 python demo.py



4. Building with non-GNU compilers
----------------------------------

As mentioned above Python's distutils uses whatever compiler Python
was compiled with to compile extension modules.  It also appears that
distutils assumes that this compiler can compile C or C++ sources as
distutils makes no differentiation between the two.  For builds using
GNU gcc and a few other compilers this is not an issue as they will
determine the type of source from the file extension.  For SunCC (and
probably other compilers that came from cfront) it won't work as the C
compiler (cc) is totally separate from the C++ compiler (CC).  This
causes distutils to attempt to compile the wxPython sources with the C
compiler, which won't work.

There may be better ways to get around this, but here is the
workaround I devised.  I created a script that will execute either cc
or CC based on the file extension given to it.  If Python uses this
script for its compiler then it will also be used by extensions built
with distutils and everybody will be more or less happy.  Here is a
copy of the script I used.  It was a fairly quick rush job so there
are probably issues with it but it worked for me.

    #!/bin/bash
    #--------------------------------------------------------------
    # Try to determine type of file being compiled and then
    # launch cc for C sources or CC for C++.
    #

    args=$@
    is_C=

    for arg in $args; do

        # is the arg a file that exists?
        if [ -e $arg ]; then

            # does it end in ".c"?
            if [ "${arg:${#arg}-2}" == ".c" ]; then
                is_C=yes
            fi
        fi
    done

    # if the flag wasn't set then assume C++ and execute CC,
    # otherwise execute cc.
    if [ -z $is_C ]; then
        exec CC -w $@
    else
        exec cc -w $@
    fi
    #--------------------------------------------------------------

I called it pycc, put it in ${prefix}/bin and set its execute
permission bit.

The next step is to configure and build Python such that it uses pycc
as it's compiler.  You can do that by setting CC in your environment
before running configure, like this in bash:

    export CC=pycc
    configure

After making and installing Python with this configuration you should
be able to build wxPython as described in the steps above.



-----------------
robin@alldunn.com