added docs about new gstreamer

[mediagoblin.git] / configure.ac

dnl configure.ac
dnl
dnl Copyright 2012, 2013 Brandon Invergo <brandon@invergo.net>
dnl           2014 MediaGoblin contributors (see MediaGoblin's AUTHORS)
dnl
dnl Copying and distribution of this file, with or without modification,
dnl are permitted in any medium without royalty provided the copyright
dnl notice and this notice are preserved.  This file is offered as-is,
dnl without any warranty.

dnl#########
dnl README #
dnl#########
dnl
dnl This is a basic Autoconf configure.ac file for Python-based
dnl projects. It is not intended to be used as-is, but rather to be
dnl modified to the specific needs of the project.
dnl
dnl Lines prefixed with "dnl" are comments that are automatically
dnl removed by Autoconf/M4, thus they will not appear in the generated
dnl configure script (see the M4 documentation for more information). 
dnl Such comments are used in this file to communicate information to 
dnl you, the developer. In some cases, the comments contain extra 
dnl macros that you might consider including in your configure script. 
dnl If you wish to include them, simply remove the "dnl" from the 
dnl beginning of the line.
dnl
dnl Lines prefixed with "#" are comments that will appear in the 
dnl generated configure script. These comments are thus used to clarify
dnl to the user what is happening in that script
dnl
dnl Wherever pyconfigure-specific macros are used, extra comments are
dnl included to describe the macros.

dnl######################
dnl Package Information #
dnl######################

dnl----
dnl Initialize Autoconf with the package metadata
dnl The arguments have been set via the project's PKG-INFO file
dnl and correspond to:
dnl
dnl 1) package name (i.e. foo)
dnl 2) package version (i.e. 1.2)
dnl 3) bug/info/project email address (i.e. bug-foo@gnu.org)
dnl----
dnl
AC_INIT([mediagoblin], [0.7.1.dev], [cwebber@gnu.org])


dnl----
dnl Load macros from the m4/ directory. If you plan to write new 
dnl macros, put them in files in this directory.
dnl----
dnl
dnl AC_CONFIG_MACRO_DIR([m4])


dnl # The default prefix should be changed from /usr/local. Set it, as in
dnl # the documentation, to /srv/mediagoblin.example.org/mediagoblin/
dnl AC_PREFIX_DEFAULT([`pwd`])


dnl###########################
dnl Program/command support  #
dnl###########################
dnl
dnl In this section, we check for the presence of important commands
dnl and programs.

dnl--A bit simpler python init----------------------------------------
dnl Expect python2.7 or python2.6 unless --with-python3 is given.
dnl----


AC_ARG_WITH([python3],
	[AS_HELP_STRING([--with-python3], [Set up to use Python 3 by default.])],
	[],
	[with_python3=no])
AS_IF([test "x$with_python3" != xno],
        AC_CHECK_PROGS([PYTHON], [python3.3], [none])
        AC_SUBST([USE_PYTHON3], [true])
	AS_IF([test "x$PYTHON" = xnone],
              [AC_MSG_FAILURE(
		[--with-python3 given but no acceptable python3 (3.3) could be found])]),
      AC_CHECK_PROGS([PYTHON], [python2.7 python2.6], [none])
      AC_SUBST([USE_PYTHON3], [false])
      AS_IF([test "x$PYTHON" = xnone],
              [AC_MSG_FAILURE(
		[No acceptable python (2.7, 2.6) could be found])]))


dnl--PC_INIT----------------------------------------------------------
dnl This is the only required macro. Its primary function is to find
dnl a Python interpreter that is compatible with the package and set 
dnl the PYTHON variable to hold its path. It can optionally take
dnl arguments to specify minimum and/or maximum versions.  This is a 
dnl convenience macro that combines the functionality of the macros
dnl PC_PROG_PYTHON and PC_PYTHON_VERIFY_VERSION
dnl PC_INIT: find an interpreter with a version between 2.0 and 3.3.99
dnl          (in other words, up to and including any possible release
dnl          in the 3.3 series)
dnl PC_INIT([MIN_VER], [MAX_VER]): Find an interpreter that is between
dnl          the minimum and maximum version. If the min is in the 2.0
dnl          series and the max is in the 3.0 series, non-existent 
dnl          releases (2.8 & 2.9) will be correctly skipped.
dnl----
dnl
dnl PC_INIT([3.3], [3.4])

dnl--PC_PROG_PYTHON---------------------------------------------------
dnl This macro provides a means of finding a Python interpreter.
dnl You may optionally pass it argument to pass a path to a binary to
dnl check for first.  You may also pass a second and third argument to
dnl specify the minimum and maximum versions to check for.  This works
dnl in a naive way by appending the major and minor release numbers to
dnl the binary name.  By default, this will first check for a binary 
dnl called "python" and then from there it will check for version-
dnl specific binaries (ie "python3", "python2.7") in decending version 
dnl order. Thus, the highest version binary will be found first. 
dnl----
dnl
dnl PC_PROG_PYTHON


dnl--PC_PYTHON_PROG_PYTHON_CONFIG-------------------------------------
dnl In order to use some of the other macros, you also need the 
dnl python-config command, which will fall subject to the same problem 
dnl of python3-config being preferred to python2-config. This macro
dnl will be automatically included if you use on of the macros that 
dnl depends on it, so you normally don't have to call it. However, if
dnl you require a specific version, you can do something like the
dnl following example.
dnl----
dnl
dnl PC_PYTHON_PROG_PYTHON_CONFIG([python2-config])
dnl if [[ "x$PYTHON_CONFIG" == "x" ]]; then
dnl    PC_PYTHON_PROG_PYTHON_CONFIG([$PYTHON-config])
dnl fi   

dnl----
dnl With the following set of macros, we implement an option 
dnl "--with-virtualenv", which the user can pass to the configure 
dnl script in order to install to a Virtualenv (AC_ARG_WITH). If the 
dnl option is specified by the user, then we check if the program is
dnl available, checking both for "virtualenv" and "virtualenv2" 
dnl (AC_CHECK_PROGS)
dnl----
dnl
# Support doing development in a virtualenv via the --with-virtualenv 
# configure flag
AC_ARG_WITH([virtualenv],
	[AS_HELP_STRING([--without-virtualenv], [install to a Python virtualenv])],
	[],
	[with_virtualenv=yes])
AS_IF([test "x$with_virtualenv" != xno],
	    AC_CHECK_PROGS([VIRTUALENV], [virtualenv virtualenv3 virtualenv2], [no])
	    AS_IF([test "x$VIRTUALENV" = xno],
	    [AC_MSG_FAILURE(
		[--with-virtualenv given but virtualenv could not be found])]),
	AC_SUBST([VIRTUALENV], [no]))
AC_ARG_VAR([VIRTUALENV_FLAGS], [flags to pass to the virtualenv command])

dnl----
dnl If the program uses sphinx-build to build documentation, uncomment 
dnl this to create a SPHINXBUILD variable in the Makefile pointing to 
dnl the program. Thus, the user would specify 
dnl SPHINXBUILD=/path/to/sphinx-build as an argument to the configure
dnl script. Since building the documentation should be optional, just
dnl print a warning. If the program uses some other documentation
dnl system, you can do something similar with it.
dnl----
dnl
dnl # Check for sphinx-build
dnl AC_CHECK_PROGS([SPHINXBUILD], [sphinx-build sphinx-build3 sphinx-build2], [no])
dnl AS_IF([test "x$SPHINXBUILD" = xno], 
dnl     AC_MSG_WARN(sphinx-build is required to build documentation))


dnl----
dnl These two are standard Autoconf macros which check for the 
dnl presence of some programs that we will use in the Makefile.
dnl----
dnl
AC_PROG_MKDIR_P
AC_PROG_INSTALL	    

dnl########################################
dnl Database stuff... maybe restore this? #
dnl########################################
dnl # Check for a supported database program
dnl AC_PATH_PROG([SQLITE], [sqlite3])
dnl AC_PATH_PROG([POSTGRES], [psql])
dnl AS_IF([test "x$SQLITE" = x -a "x$POSTGRES" = "x"],
dnl    [AC_MSG_ERROR([SQLite or PostgreSQL is required])])


dnl#################################
dnl Python installation properties #
dnl#################################
dnl
dnl In this section, we test for various aspects of the Python 
dnl installation on the user's computer. 

dnl--PC_PYTHON_VERIFY_VERSION & PC_PYTHON_CHECK_VERSION----------------
dnl PC_PYTHON_VERIFY_VERSION is used to check if the version of the 
dnl discovered Python binary meets some requirement. The first argument 
dnl should be a Python-compatible numerical comparison operator (i.e. 
dnl "==", "<", ">=", etc.). The second argument should be the version to 
dnl test against. Finally, you may optionally provide actions to take if 
dnl it does (3rd argument) or if it does not (4th argument) meet the 
dnl requirement.
dnl
dnl PC_PYTHON_CHECK_VERSION simply fetches the version number of the
dnl Python interpreter stored in the PYTHON variable
dnl----
dnl
dnl PC_PYTHON_VERIFY_VERSION([>=], [2.7.1], [AC_MSG_RESULT([yes])],
dnl	AC_MSG_FAILURE(Python 2 (python_min_ver+) is required))


dnl--PC_PYTHON_CHECK_PREFIX--------------------------------------------
dnl This macro finds out what Python thinks is the PREFIX
dnl (i.e. /usr) and stores it in PYTHON_PREFIX. You probably shouldn't
dnl use this and you should just stick to $prefix, but here it is
dnl anyway.
dnl----
dnl
dnl PC_PYTHON_CHECK_PREFIX


dnl--PC_PYTHON_CHECK_EXEC_PREFIX---------------------------------------
dnl The same as above but for $exec-prefix
dnl----
dnl
dnl PC_PYTHON_CHECK_EXEC_PREFIX


dnl--PC_PYTHON_CHECK_PLATFORM------------------------------------------
dnl This macro checks what platform Python thinks this is (ie
dnl "linux2") and stores it in PYTHON_PLATFORM
dnl----
dnl
dnl PC_PYTHON_CHECK_PLATFORM


dnl--PC_PYTHON_CHECK_SITE_DIR------------------------------------------
dnl This checks where Python packages are installed (usually 
dnl /usr/lib/pythonX.Y/site-packages) and stores it in the variable
dnl pythondir.
dnl----
dnl
dnl PC_PYTHON_CHECK_SITE_DIR


dnl--PC_PYTHON_SITE_PACKAGE_DIR---------------------------------------
dnl This uses PYTHON_SITE_DIR to construct a directory for this
dnl project (ie $PYTHON_SITE_DIR/project_name) and stores it in
dnl pkgpythondir. This value is used by Automake for installing Python
dnl scripts. By default, this begins with $pythondir, unexpanded, to
dnl provide compatibility with GNU Makefile specifications, allowing
dnl the user to change the prefix from the commandline.
dnl----
dnl
dnl PC_PYTHON_SITE_PACKAGE_DIR


dnl--PC_PYTHON_CHECK_EXEC_DIR------------------------------------------
dnl Same as PC_PYTHON_CHECK_SITE_DIR but for $exec-prefix. Stored in
dnl pyexecdir
dnl----
dnl
dnl PC_PYTHON_CHECK_EXEC_DIR

dnl--PC_PYTHON_EXEC_PACKAGE_DIR----------------------------------------
dnl Same as PC_PYTHON_SITE_PACKAGE_DIR but for $exec-prefix. Stored in
dnl pkgpyexecdir
dnl----
dnl
dnl PC_PYTHON_EXEC_PACKAGE_DIR


dnl###############################
dnl Checking Python capabilities #
dnl###############################

dnl--PC_PYTHON_CHECK_MODULE([PYTHON-MODULE], [ACTION-IF-PRESENT],
dnl                         [ACTION-IF-ABSENT]) 
dnl This macro lets you check if a given Python module exists on the
dnl system.
dnl----
dnl
dnl PC_PYTHON_CHECK_MODULE([foo])


dnl # Check for python-lxml module
dnl PC_PYTHON_CHECK_MODULE([lxml], [], 
dnl                        [AC_MSG_ERROR([python-lxml is required])])
dnl 
dnl # Check for the Python Imaging Library
dnl PC_PYTHON_CHECK_MODULE([Image], [],
dnl                        [AC_MSG_ERROR([Python Imaging Library is required])])


dnl--PC_PYTHON_CHECK_FUNC([PYTHON-MODULE], [FUNCTION], [ARGS], 
dnl                       [ACTION-IF-SUCCESSFUL], [ACTION-IF-FAIL]) 
dnl
dnl This macro lets you test if a given function, possibly contained
dnl in a given module, exists. If any exception is encountered when
dnl calling this function, the check will fail. 
dnl----
dnl
dnl # test if Python library foo can do bar()
dnl PC_PYTHON_CHECK_FUNC([foo], [bar])


dnl Advanced notes:
dnl m4/python.m4 implements Python as a language in Autoconf. This
dnl means that you can use all the usual AC_LANG_* macros with Python
dnl and it will behave as expected. In particular, this means that you
dnl can run arbitrary Python code. For example:
dnl
dnl AC_LANG_PUSH(Python)[]
dnl AC_RUN_IFELSE([AC_LANG_PROGRAM([dnl
dnl # some code here
dnl import foo
dnl ], [dnl
dnl     # some more code here
dnl     foo.bar()
dnl ])], [ACTION-IF-SUCCESSFUL], [ACTION-IF-FAILED])
dnl AC_LANG_POP(Python)[]
dnl  
dnl As usual, AC_LANG_PROGRAM takes two arguments, PROLOG code and
dnl MAIN code. The PROLOG code goes verbatim at the top of the file,
dnl while the MAIN code is embedded in an if __name__ == "__main__":
dnl block. Python's indentation rules complicate things, however. In
dnl particular, you must be sure that all of the code in MAIN is
dnl indented once by default. PROLOG code does not require this.


dnl##################################
dnl Python module build environment #
dnl##################################
dnl
dnl Here we check for necessary information for building Python modules
dnl written in C

dnl--PC_PYTHON_CHECK_INCLUDES------------------------------------------
dnl This macro figures out the include flags necessary for loading the
dnl Python headers (ie -I/usr/lib/python). The results are stored in
dnl PYTHON_INCLUDES
dnl----
dnl
dnl PC_PYTHON_CHECK_INCLUDES


dnl--PC_PYTHON_CHECK_HEADERS([ACTION-IF-PRESENT], [ACTION-IF-ABSENT])--
dnl Using the information found from PC_PYTHON_CHECK_INCLUDES, check
dnl to make sure that Python.h can be loaded. Note that if you use
dnl this, you don't strictly need to also include
dnl PC_PYTHON_CHECK_INCLUDES.
dnl----
dnl
dnl PC_PYTHON_CHECK_HEADERS(,[AC_MSG_ERROR(could not find Python headers)])


dnl--PC_PYTHON_CHECK_LIBS----------------------------------------------
dnl This checks what LIBS flags are necessary to use the Python
dnl libraries (ie -lpython). The results are stored in PYTHON_LIBS
dnl----
dnl
dnl PC_PYTHON_CHECK_LIBS


dnl--PC_PYTHON_TEST_LIBS([FUNCTION-TO-TEST], [ACTION-IF-PRESENT], [ACTION-IF-ABSENT])
dnl This checks whether the LIBS flag for libpython discovered with
dnl PC_PYTHON_CHECK_LIBS is loadable and if a given function can be
dnl found in the library. You may use this to test for the presence of
dnl features in the library. 
dnl----
dnl
dnl PC_PYTHON_TEST_LIBS([PyObject_Print],,
dnl                     [AC_MSG_ERROR(The Python library could not be loaded)])
dnl # Add PYTHON_LIBS to LIBS
dnl LIBS="$LIBS $PYTHON_LIBS"


dnl--PC_PYTHON_CHECK_CFLAGS--------------------------------------------
dnl This macro checks what Python thinks are the proper CFLAGS to
dnl use and stores them in PYTHON_CFLAGS. Note that this info is only
dnl available for Python versions which include a python-config tool
dnl (2.5+).
dnl----
dnl
dnl PC_PYTHON_CHECK_CFLAGS
dnl # Add PYTHON_CFLAGS to CFLAGS
dnl CFLAGS="$CFLAGS $PYTHON_CFLAGS"


dnl--PC_PYTHON_CHECK_LDFLAGS-------------------------------------------
dnl The same as above but for LDFLAGS
dnl----
dnl
dnl PC_PYTHON_CHECK_LDFLAGS
dnl # Add PYTHON_LDFLAGS to LDFLAGS
dnl LDFLAGS="$LDFLAGS $PYTHON_LDFLAGS"


dnl--PC_PYTHON_CHECK_EXTENSION_SUFFIX----------------------------------
dnl This checks for what Python expects the suffix of extension
dnl modules to be (i.e. .cpython-32mu.so) and stores it in
dnl PYTHON_EXTENSION SUFFIX. This information is only available for
dnl Python 3+
dnl----
dnl
dnl PC_PYTHON_CHECK_EXTENSION_SUFFIX


dnl--PC_PYTHON_CHECK_ABI_FLAGS----------------------------------------
dnl This checks for the ABI flags used by Python (i.e. "mu") and
dnl stores it in PYTHON_ABI_FLAGS. This information is only available
dnl for Python 3+
dnl----
dnl
dnl PC_PYTHON_CHECK_ABI_FLAGS


dnl--MediaGoblin specific commands/variables ------------------------


dnl#########
dnl Finish #
dnl#########

dnl Define the files to be configured
AC_CONFIG_FILES([Makefile])

dnl Generate config.status
AC_OUTPUT