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author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2013-12-11 21:26:36 +0100 |
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committer | Peter Korsgaard <peter@korsgaard.com> | 2013-12-15 13:32:12 +0100 |
commit | a6bba674a257f291c51a3859381f653e711bd354 (patch) | |
tree | b7bae7c451509b6cfb376201c63eaabd3e73af17 /docs/manual/adding-packages-python.txt | |
parent | c1781787f8425d7baea3e399667dac97e8850665 (diff) | |
download | buildroot-a6bba674a257f291c51a3859381f653e711bd354.tar.gz buildroot-a6bba674a257f291c51a3859381f653e711bd354.zip |
package: introduce Python package infrastructure
[Peter: fix s/BUILD_TYPE/SETUP_TYPE/ typo in manual as noted by Samuel]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Diffstat (limited to 'docs/manual/adding-packages-python.txt')
-rw-r--r-- | docs/manual/adding-packages-python.txt | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/docs/manual/adding-packages-python.txt b/docs/manual/adding-packages-python.txt new file mode 100644 index 0000000000..b8d5331b1d --- /dev/null +++ b/docs/manual/adding-packages-python.txt @@ -0,0 +1,159 @@ +// -*- mode:doc; -*- +// vim: set syntax=asciidoc: + +Infrastructure for Python packages +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This infrastructure applies to Python packages that use the standard +Python setuptools mechanism as their build system, generally +recognizable by the usage of a +setup.py+ script. + +[[python-package-tutorial]] + ++python-package+ tutorial +^^^^^^^^^^^^^^^^^^^^^^^^^ + +First, let's see how to write a +.mk+ file for a Python package, +with an example : + +------------------------ +01: ################################################################################ +02: # +03: # python-foo +04: # +05: ################################################################################ +06: +07: PYTHON_FOO_VERSION = 1.0 +08: PYTHON_FOO_SOURCE = python-foo-$(LIBFOO_VERSION).tar.xz +09: PYTHON_FOO_SITE = http://www.foosoftware.org/download +10: PYTHON_FOO_LICENSE = BSD-3c +11: PYTHON_FOO_LICENSE_FILES = LICENSE +12: PYTHON_FOO_ENV = SOME_VAR=1 +13: PYTHON_FOO_DEPENDENCIES = libmad +14: PYTHON_FOO_SETUP_TYPE = distutils +15: +16: $(eval $(python-package)) +------------------------ + +On line 7, we declare the version of the package. + +On line 8 and 9, we declare the name of the tarball (xz-ed tarball +recommended) and the location of the tarball on the Web. Buildroot +will automatically download the tarball from this location. + +On line 10 and 11, we give licensing details about the package (its +license on line 10, and the file containing the license text on line +11). + +On line 12, we tell Buildroot to pass custom options to the Python ++setup.py+ script when it is configuring the package. + +On line 13, we declare our dependencies, so that they are built +before the build process of our package starts. + +On line 14, we declare the specific Python build system being used. In +this case the +distutils+ Python build system is used. The two +supported ones are +distutils+ and +setuptools+. + +Finally, on line 16, we invoke the +python-package+ macro that +generates all the Makefile rules that actually allow the package to be +built. + +[[python-package-reference]] + ++python-package+ reference +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +As a policy, packages that merely provide Python modules should all be +named +python-<something>+ in Buildroot. Other packages that use the +Python build system, but are not Python modules, can freely choose +their name (existing examples in Buildroot are +scons+ and ++supervisor+). + +In their +Config.in+ file, they should depend on +BR2_PACKAGE_PYTHON+ +so that when Buildroot will enable Python 3 usage for modules, we will +be able to enable Python modules progressively on Python 3. + +The main macro of the Python package infrastructure is ++python-package+. It is similar to the +generic-package+ macro. It is +also possible to create Python host packages with the ++host-python-package+ macro. + +Just like the generic infrastructure, the Python infrastructure works +by defining a number of variables before calling the +python-package+ +or +host-python-package+ macros. + +All the package metadata information variables that exist in the +xref:generic-package-reference[generic package infrastructure] also +exist in the Python infrastructure: +PYTHON_FOO_VERSION+, ++PYTHON_FOO_SOURCE+, +PYTHON_FOO_PATCH+, +PYTHON_FOO_SITE+, ++PYTHON_FOO_SUBDIR+, +PYTHON_FOO_DEPENDENCIES+, +PYTHON_FOO_LICENSE+, ++PYTHON_FOO_LICENSE_FILES+, etc. + +Note that: + + * Setting +PYTHON_FOO_INSTALL_STAGING+ to +YES+ has no effect (unless + a +PYTHON_FOO_INSTALL_STAGING_CMDS+ variable is defined), since + Python modules generally don't need to be installed to the + +staging+ directory. + + * It is not necessary to add +python+ or +host-python+ in the + +PYTHON_FOO_DEPENDENCIES+ variable of a package, since these basic + dependencies are automatically added as needed by the Python + package infrastructure. + + * Similarly, it is not needed to add +host-setuptools+ and/or + +host-distutilscross+ dependencies to +PYTHON_FOO_DEPENDENCIES+ for + setuptools-based packages, since these are automatically added by + the Python infrastructure as needed. + +One variable specific to the Python infrastructure is mandatory: + +* +PYTHON_FOO_SETUP_TYPE+, to define which Python build system is used + by the package. The two supported values are +distutils+ and + +setuptools+. If you don't know which one is used in your package, + look at the +setup.py+ file in your package source code, and see + whether it imports things from the +distutils+ module or the + +setuptools+ module. + +A few additional variables, specific to the Python infrastructure, can +optionally be defined, depending on the package's needs. Many of them +are only useful in very specific cases, typical packages will +therefore only use a few of them, or none. + +* +PYTHON_FOO_ENV+, to specify additional environment variables to + pass to the Python +setup.py+ script (for both the build and install + steps). Note that the infrastructure is automatically passing + several standard variables, defined in +PKG_PYTHON_DISTUTILS_ENV+ + (for distutils target packages), +HOST_PKG_PYTHON_DISTUTILS_ENV+ + (for distutils host packages), +PKG_PYTHON_SETUPTOOLS_ENV+ (for + setuptools target packages) and +HOST_PKG_PYTHON_SETUPTOOLS_ENV+ + (for setuptools host packages). + +* +PYTHON_FOO_BUILD_OPT+, to specify additional options to pass to the + Python +setup.py+ script during the build step. For target distutils + packages, the +PKG_PYTHON_DISTUTILS_BUILD_OPT+ options are already + passed automatically by the infrastructure. + +* +PYTHON_FOO_INSTALL_OPT+, to specify additional options to pass to + the Python +setup.py+ script during the installation step. Note that + the infrastructure is automatically passing some options, defined in + +PKG_PYTHON_DISTUTILS_INSTALL_OPT+ (for target distutils packages), + +HOST_PKG_PYTHON_DISTUTILS_INSTALL_OPT+ (for host distutils + packages), +PKG_PYTHON_SETUPTOOLS_INSTALL_OPT+ (for target + setuptools packages) and +HOST_PKG_PYTHON_SETUPTOOLS_INSTALL_OPT+ + (for host setuptools packages). + +With the Python infrastructure, all the steps required to build and +install the packages are already defined, and they generally work well +for most Python-based packages. However, when required, it is still +possible to customize what is done in any particular step: + +* By adding a post-operation hook (after extract, patch, configure, + build or install). See xref:hooks[] for details. + +* By overriding one of the steps. For example, even if the Python + infrastructure is used, if the package +.mk+ file defines its own + +PYTHON_FOO_BUILD_CMDS+ variable, it will be used instead of the + default Python one. However, using this method should be restricted + to very specific cases. Do not use it in the general case. |