mirror of https://github.com/python/cpython
936 lines
26 KiB
ReStructuredText
936 lines
26 KiB
ReStructuredText
****************
|
|
Configure Python
|
|
****************
|
|
|
|
.. _configure-options:
|
|
|
|
Configure Options
|
|
=================
|
|
|
|
List all ``./configure`` script options using::
|
|
|
|
./configure --help
|
|
|
|
See also the :file:`Misc/SpecialBuilds.txt` in the Python source distribution.
|
|
|
|
General Options
|
|
---------------
|
|
|
|
.. cmdoption:: --enable-loadable-sqlite-extensions
|
|
|
|
Support loadable extensions in the :mod:`_sqlite` extension module (default
|
|
is no).
|
|
|
|
See the :meth:`sqlite3.Connection.enable_load_extension` method of the
|
|
:mod:`sqlite3` module.
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. cmdoption:: --disable-ipv6
|
|
|
|
Disable IPv6 support (enabled by default if supported), see the
|
|
:mod:`socket` module.
|
|
|
|
.. cmdoption:: --enable-big-digits=[15|30]
|
|
|
|
Define the size in bits of Python :class:`int` digits: 15 or 30 bits.
|
|
|
|
By default, the digit size is 30.
|
|
|
|
Define the ``PYLONG_BITS_IN_DIGIT`` to ``15`` or ``30``.
|
|
|
|
See :data:`sys.int_info.bits_per_digit <sys.int_info>`.
|
|
|
|
.. cmdoption:: --with-suffix=SUFFIX
|
|
|
|
Set the Python executable suffix to *SUFFIX*.
|
|
|
|
The default suffix is ``.exe`` on Windows and macOS (``python.exe``
|
|
executable), ``.js`` on Emscripten node, ``.html`` on Emscripten browser,
|
|
``.wasm`` on WASI, and an empty string on other platforms (``python``
|
|
executable).
|
|
|
|
.. versionchanged:: 3.11
|
|
The default suffix on WASM platform is one of ``.js``, ``.html``
|
|
or ``.wasm``.
|
|
|
|
.. cmdoption:: --with-tzpath=<list of absolute paths separated by pathsep>
|
|
|
|
Select the default time zone search path for :data:`zoneinfo.TZPATH`.
|
|
See the :ref:`Compile-time configuration
|
|
<zoneinfo_data_compile_time_config>` of the :mod:`zoneinfo` module.
|
|
|
|
Default: ``/usr/share/zoneinfo:/usr/lib/zoneinfo:/usr/share/lib/zoneinfo:/etc/zoneinfo``.
|
|
|
|
See :data:`os.pathsep` path separator.
|
|
|
|
.. versionadded:: 3.9
|
|
|
|
.. cmdoption:: --without-decimal-contextvar
|
|
|
|
Build the ``_decimal`` extension module using a thread-local context rather
|
|
than a coroutine-local context (default), see the :mod:`decimal` module.
|
|
|
|
See :data:`decimal.HAVE_CONTEXTVAR` and the :mod:`contextvars` module.
|
|
|
|
.. versionadded:: 3.9
|
|
|
|
.. cmdoption:: --with-dbmliborder=<list of backend names>
|
|
|
|
Override order to check db backends for the :mod:`dbm` module
|
|
|
|
A valid value is a colon (``:``) separated string with the backend names:
|
|
|
|
* ``ndbm``;
|
|
* ``gdbm``;
|
|
* ``bdb``.
|
|
|
|
.. cmdoption:: --without-c-locale-coercion
|
|
|
|
Disable C locale coercion to a UTF-8 based locale (enabled by default).
|
|
|
|
Don't define the ``PY_COERCE_C_LOCALE`` macro.
|
|
|
|
See :envvar:`PYTHONCOERCECLOCALE` and the :pep:`538`.
|
|
|
|
.. cmdoption:: --with-platlibdir=DIRNAME
|
|
|
|
Python library directory name (default is ``lib``).
|
|
|
|
Fedora and SuSE use ``lib64`` on 64-bit platforms.
|
|
|
|
See :data:`sys.platlibdir`.
|
|
|
|
.. versionadded:: 3.9
|
|
|
|
.. cmdoption:: --with-wheel-pkg-dir=PATH
|
|
|
|
Directory of wheel packages used by the :mod:`ensurepip` module
|
|
(none by default).
|
|
|
|
Some Linux distribution packaging policies recommend against bundling
|
|
dependencies. For example, Fedora installs wheel packages in the
|
|
``/usr/share/python-wheels/`` directory and don't install the
|
|
:mod:`ensurepip._bundled` package.
|
|
|
|
.. versionadded:: 3.10
|
|
|
|
.. cmdoption:: --with-pkg-config=[check|yes|no]
|
|
|
|
Whether configure should use :program:`pkg-config` to detect build
|
|
dependencies.
|
|
|
|
* ``check`` (default): :program:`pkg-config` is optional
|
|
* ``yes``: :program:`pkg-config` is mandatory
|
|
* ``no``: configure does not use :program:`pkg-config` even when present
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
.. cmdoption:: --enable-pystats
|
|
|
|
Turn on internal statistics gathering.
|
|
|
|
The statistics will be dumped to a arbitrary (probably unique) file in
|
|
``/tmp/py_stats/``, or ``C:\temp\py_stats\`` on Windows.
|
|
|
|
Use ``Tools/scripts/summarize_stats.py`` to read the stats.
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
WebAssembly Options
|
|
-------------------
|
|
|
|
.. cmdoption:: --with-emscripten-target=[browser|node]
|
|
|
|
Set build flavor for ``wasm32-emscripten``.
|
|
|
|
* ``browser`` (default): preload minimal stdlib, default MEMFS.
|
|
* ``node``: NODERAWFS and pthread support.
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
.. cmdoption:: --enable-wasm-dynamic-linking
|
|
|
|
Turn on dynamic linking support for WASM.
|
|
|
|
Dynamic linking enables ``dlopen``. File size of the executable
|
|
increases due to limited dead code elimination and additional features.
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
.. cmdoption:: --enable-wasm-pthreads
|
|
|
|
Turn on pthreads support for WASM.
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
|
|
Install Options
|
|
---------------
|
|
|
|
.. cmdoption:: --disable-test-modules
|
|
|
|
Don't build nor install test modules, like the :mod:`test` package or the
|
|
:mod:`_testcapi` extension module (built and installed by default).
|
|
|
|
.. versionadded:: 3.10
|
|
|
|
.. cmdoption:: --with-ensurepip=[upgrade|install|no]
|
|
|
|
Select the :mod:`ensurepip` command run on Python installation:
|
|
|
|
* ``upgrade`` (default): run ``python -m ensurepip --altinstall --upgrade``
|
|
command.
|
|
* ``install``: run ``python -m ensurepip --altinstall`` command;
|
|
* ``no``: don't run ensurepip;
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
|
|
Performance options
|
|
-------------------
|
|
|
|
Configuring Python using ``--enable-optimizations --with-lto`` (PGO + LTO) is
|
|
recommended for best performance. The experimental ``--enable-bolt`` flag can
|
|
also be used to improve performance.
|
|
|
|
.. cmdoption:: --enable-optimizations
|
|
|
|
Enable Profile Guided Optimization (PGO) using :envvar:`PROFILE_TASK`
|
|
(disabled by default).
|
|
|
|
The C compiler Clang requires ``llvm-profdata`` program for PGO. On
|
|
macOS, GCC also requires it: GCC is just an alias to Clang on macOS.
|
|
|
|
Disable also semantic interposition in libpython if ``--enable-shared`` and
|
|
GCC is used: add ``-fno-semantic-interposition`` to the compiler and linker
|
|
flags.
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. versionchanged:: 3.10
|
|
Use ``-fno-semantic-interposition`` on GCC.
|
|
|
|
.. envvar:: PROFILE_TASK
|
|
|
|
Environment variable used in the Makefile: Python command line arguments for
|
|
the PGO generation task.
|
|
|
|
Default: ``-m test --pgo --timeout=$(TESTTIMEOUT)``.
|
|
|
|
.. versionadded:: 3.8
|
|
|
|
.. cmdoption:: --with-lto=[full|thin|no|yes]
|
|
|
|
Enable Link Time Optimization (LTO) in any build (disabled by default).
|
|
|
|
The C compiler Clang requires ``llvm-ar`` for LTO (``ar`` on macOS), as well
|
|
as an LTO-aware linker (``ld.gold`` or ``lld``).
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. versionadded:: 3.11
|
|
To use ThinLTO feature, use ``--with-lto=thin`` on Clang.
|
|
|
|
.. versionchanged:: 3.12
|
|
Use ThinLTO as the default optimization policy on Clang if the compiler accepts the flag.
|
|
|
|
.. cmdoption:: --enable-bolt
|
|
|
|
Enable usage of the `BOLT post-link binary optimizer
|
|
<https://github.com/llvm/llvm-project/tree/main/bolt>`_ (disabled by
|
|
default).
|
|
|
|
BOLT is part of the LLVM project but is not always included in their binary
|
|
distributions. This flag requires that ``llvm-bolt`` and ``merge-fdata``
|
|
are available.
|
|
|
|
BOLT is still a fairly new project so this flag should be considered
|
|
experimental for now. Because this tool operates on machine code its success
|
|
is dependent on a combination of the build environment + the other
|
|
optimization configure args + the CPU architecture, and not all combinations
|
|
are supported.
|
|
|
|
.. versionadded:: 3.12
|
|
|
|
.. cmdoption:: --with-computed-gotos
|
|
|
|
Enable computed gotos in evaluation loop (enabled by default on supported
|
|
compilers).
|
|
|
|
.. cmdoption:: --without-pymalloc
|
|
|
|
Disable the specialized Python memory allocator :ref:`pymalloc <pymalloc>`
|
|
(enabled by default).
|
|
|
|
See also :envvar:`PYTHONMALLOC` environment variable.
|
|
|
|
.. cmdoption:: --without-doc-strings
|
|
|
|
Disable static documentation strings to reduce the memory footprint (enabled
|
|
by default). Documentation strings defined in Python are not affected.
|
|
|
|
Don't define the ``WITH_DOC_STRINGS`` macro.
|
|
|
|
See the ``PyDoc_STRVAR()`` macro.
|
|
|
|
.. cmdoption:: --enable-profiling
|
|
|
|
Enable C-level code profiling with ``gprof`` (disabled by default).
|
|
|
|
|
|
.. _debug-build:
|
|
|
|
Python Debug Build
|
|
------------------
|
|
|
|
A debug build is Python built with the :option:`--with-pydebug` configure
|
|
option.
|
|
|
|
Effects of a debug build:
|
|
|
|
* Display all warnings by default: the list of default warning filters is empty
|
|
in the :mod:`warnings` module.
|
|
* Add ``d`` to :data:`sys.abiflags`.
|
|
* Add :func:`sys.gettotalrefcount` function.
|
|
* Add :option:`-X showrefcount <-X>` command line option.
|
|
* Add :option:`-d` command line option and :envvar:`PYTHONDEBUG` environment
|
|
variable to debug the parser.
|
|
* Add support for the ``__lltrace__`` variable: enable low-level tracing in the
|
|
bytecode evaluation loop if the variable is defined.
|
|
* Install :ref:`debug hooks on memory allocators <default-memory-allocators>`
|
|
to detect buffer overflow and other memory errors.
|
|
* Define ``Py_DEBUG`` and ``Py_REF_DEBUG`` macros.
|
|
* Add runtime checks: code surrounded by ``#ifdef Py_DEBUG`` and ``#endif``.
|
|
Enable ``assert(...)`` and ``_PyObject_ASSERT(...)`` assertions: don't set
|
|
the ``NDEBUG`` macro (see also the :option:`--with-assertions` configure
|
|
option). Main runtime checks:
|
|
|
|
* Add sanity checks on the function arguments.
|
|
* Unicode and int objects are created with their memory filled with a pattern
|
|
to detect usage of uninitialized objects.
|
|
* Ensure that functions which can clear or replace the current exception are
|
|
not called with an exception raised.
|
|
* Check that deallocator functions don't change the current exception.
|
|
* The garbage collector (:func:`gc.collect` function) runs some basic checks
|
|
on objects consistency.
|
|
* The :c:macro:`Py_SAFE_DOWNCAST()` macro checks for integer underflow and
|
|
overflow when downcasting from wide types to narrow types.
|
|
|
|
See also the :ref:`Python Development Mode <devmode>` and the
|
|
:option:`--with-trace-refs` configure option.
|
|
|
|
.. versionchanged:: 3.8
|
|
Release builds and debug builds are now ABI compatible: defining the
|
|
``Py_DEBUG`` macro no longer implies the ``Py_TRACE_REFS`` macro (see the
|
|
:option:`--with-trace-refs` option), which introduces the only ABI
|
|
incompatibility.
|
|
|
|
|
|
Debug options
|
|
-------------
|
|
|
|
.. cmdoption:: --with-pydebug
|
|
|
|
:ref:`Build Python in debug mode <debug-build>`: define the ``Py_DEBUG``
|
|
macro (disabled by default).
|
|
|
|
.. cmdoption:: --with-trace-refs
|
|
|
|
Enable tracing references for debugging purpose (disabled by default).
|
|
|
|
Effects:
|
|
|
|
* Define the ``Py_TRACE_REFS`` macro.
|
|
* Add :func:`sys.getobjects` function.
|
|
* Add :envvar:`PYTHONDUMPREFS` environment variable.
|
|
|
|
This build is not ABI compatible with release build (default build) or debug
|
|
build (``Py_DEBUG`` and ``Py_REF_DEBUG`` macros).
|
|
|
|
.. versionadded:: 3.8
|
|
|
|
.. cmdoption:: --with-assertions
|
|
|
|
Build with C assertions enabled (default is no): ``assert(...);`` and
|
|
``_PyObject_ASSERT(...);``.
|
|
|
|
If set, the ``NDEBUG`` macro is not defined in the :envvar:`OPT` compiler
|
|
variable.
|
|
|
|
See also the :option:`--with-pydebug` option (:ref:`debug build
|
|
<debug-build>`) which also enables assertions.
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. cmdoption:: --with-valgrind
|
|
|
|
Enable Valgrind support (default is no).
|
|
|
|
.. cmdoption:: --with-dtrace
|
|
|
|
Enable DTrace support (default is no).
|
|
|
|
See :ref:`Instrumenting CPython with DTrace and SystemTap
|
|
<instrumentation>`.
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. cmdoption:: --with-address-sanitizer
|
|
|
|
Enable AddressSanitizer memory error detector, ``asan`` (default is no).
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. cmdoption:: --with-memory-sanitizer
|
|
|
|
Enable MemorySanitizer allocation error detector, ``msan`` (default is no).
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. cmdoption:: --with-undefined-behavior-sanitizer
|
|
|
|
Enable UndefinedBehaviorSanitizer undefined behaviour detector, ``ubsan``
|
|
(default is no).
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
|
|
Linker options
|
|
--------------
|
|
|
|
.. cmdoption:: --enable-shared
|
|
|
|
Enable building a shared Python library: ``libpython`` (default is no).
|
|
|
|
.. cmdoption:: --without-static-libpython
|
|
|
|
Do not build ``libpythonMAJOR.MINOR.a`` and do not install ``python.o``
|
|
(built and enabled by default).
|
|
|
|
.. versionadded:: 3.10
|
|
|
|
|
|
Libraries options
|
|
-----------------
|
|
|
|
.. cmdoption:: --with-libs='lib1 ...'
|
|
|
|
Link against additional libraries (default is no).
|
|
|
|
.. cmdoption:: --with-system-expat
|
|
|
|
Build the :mod:`pyexpat` module using an installed ``expat`` library
|
|
(default is no).
|
|
|
|
.. cmdoption:: --with-system-ffi
|
|
|
|
Build the :mod:`_ctypes` extension module using an installed ``ffi``
|
|
library, see the :mod:`ctypes` module (default is system-dependent).
|
|
|
|
.. cmdoption:: --with-system-libmpdec
|
|
|
|
Build the ``_decimal`` extension module using an installed ``mpdec``
|
|
library, see the :mod:`decimal` module (default is no).
|
|
|
|
.. versionadded:: 3.3
|
|
|
|
.. cmdoption:: --with-readline=editline
|
|
|
|
Use ``editline`` library for backend of the :mod:`readline` module.
|
|
|
|
Define the ``WITH_EDITLINE`` macro.
|
|
|
|
.. versionadded:: 3.10
|
|
|
|
.. cmdoption:: --without-readline
|
|
|
|
Don't build the :mod:`readline` module (built by default).
|
|
|
|
Don't define the ``HAVE_LIBREADLINE`` macro.
|
|
|
|
.. versionadded:: 3.10
|
|
|
|
.. cmdoption:: --with-libm=STRING
|
|
|
|
Override ``libm`` math library to *STRING* (default is system-dependent).
|
|
|
|
.. cmdoption:: --with-libc=STRING
|
|
|
|
Override ``libc`` C library to *STRING* (default is system-dependent).
|
|
|
|
.. cmdoption:: --with-openssl=DIR
|
|
|
|
Root of the OpenSSL directory.
|
|
|
|
.. versionadded:: 3.7
|
|
|
|
.. cmdoption:: --with-openssl-rpath=[no|auto|DIR]
|
|
|
|
Set runtime library directory (rpath) for OpenSSL libraries:
|
|
|
|
* ``no`` (default): don't set rpath;
|
|
* ``auto``: auto-detect rpath from :option:`--with-openssl` and
|
|
``pkg-config``;
|
|
* *DIR*: set an explicit rpath.
|
|
|
|
.. versionadded:: 3.10
|
|
|
|
|
|
Security Options
|
|
----------------
|
|
|
|
.. cmdoption:: --with-hash-algorithm=[fnv|siphash13|siphash24]
|
|
|
|
Select hash algorithm for use in ``Python/pyhash.c``:
|
|
|
|
* ``siphash13`` (default);
|
|
* ``siphash24``;
|
|
* ``fnv``.
|
|
|
|
.. versionadded:: 3.4
|
|
|
|
.. versionadded:: 3.11
|
|
``siphash13`` is added and it is the new default.
|
|
|
|
.. cmdoption:: --with-builtin-hashlib-hashes=md5,sha1,sha256,sha512,sha3,blake2
|
|
|
|
Built-in hash modules:
|
|
|
|
* ``md5``;
|
|
* ``sha1``;
|
|
* ``sha256``;
|
|
* ``sha512``;
|
|
* ``sha3`` (with shake);
|
|
* ``blake2``.
|
|
|
|
.. versionadded:: 3.9
|
|
|
|
.. cmdoption:: --with-ssl-default-suites=[python|openssl|STRING]
|
|
|
|
Override the OpenSSL default cipher suites string:
|
|
|
|
* ``python`` (default): use Python's preferred selection;
|
|
* ``openssl``: leave OpenSSL's defaults untouched;
|
|
* *STRING*: use a custom string
|
|
|
|
See the :mod:`ssl` module.
|
|
|
|
.. versionadded:: 3.7
|
|
|
|
.. versionchanged:: 3.10
|
|
|
|
The settings ``python`` and *STRING* also set TLS 1.2 as minimum
|
|
protocol version.
|
|
|
|
macOS Options
|
|
-------------
|
|
|
|
See ``Mac/README.rst``.
|
|
|
|
.. cmdoption:: --enable-universalsdk
|
|
.. cmdoption:: --enable-universalsdk=SDKDIR
|
|
|
|
Create a universal binary build. *SDKDIR* specifies which macOS SDK should
|
|
be used to perform the build (default is no).
|
|
|
|
.. cmdoption:: --enable-framework
|
|
.. cmdoption:: --enable-framework=INSTALLDIR
|
|
|
|
Create a Python.framework rather than a traditional Unix install. Optional
|
|
*INSTALLDIR* specifies the installation path (default is no).
|
|
|
|
.. cmdoption:: --with-universal-archs=ARCH
|
|
|
|
Specify the kind of universal binary that should be created. This option is
|
|
only valid when :option:`--enable-universalsdk` is set.
|
|
|
|
Options:
|
|
|
|
* ``universal2``;
|
|
* ``32-bit``;
|
|
* ``64-bit``;
|
|
* ``3-way``;
|
|
* ``intel``;
|
|
* ``intel-32``;
|
|
* ``intel-64``;
|
|
* ``all``.
|
|
|
|
.. cmdoption:: --with-framework-name=FRAMEWORK
|
|
|
|
Specify the name for the python framework on macOS only valid when
|
|
:option:`--enable-framework` is set (default: ``Python``).
|
|
|
|
|
|
Cross Compiling Options
|
|
-----------------------
|
|
|
|
Cross compiling, also known as cross building, can be used to build Python
|
|
for another CPU architecture or platform. Cross compiling requires a Python
|
|
interpreter for the build platform. The version of the build Python must match
|
|
the version of the cross compiled host Python.
|
|
|
|
.. cmdoption:: --build=BUILD
|
|
|
|
configure for building on BUILD, usually guessed by :program:`config.guess`.
|
|
|
|
.. cmdoption:: --host=HOST
|
|
|
|
cross-compile to build programs to run on HOST (target platform)
|
|
|
|
.. cmdoption:: --with-build-python=path/to/python
|
|
|
|
path to build ``python`` binary for cross compiling
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
.. cmdoption:: CONFIG_SITE=file
|
|
|
|
An environment variable that points to a file with configure overrides.
|
|
|
|
Example *config.site* file::
|
|
|
|
# config.site-aarch64
|
|
ac_cv_buggy_getaddrinfo=no
|
|
ac_cv_file__dev_ptmx=yes
|
|
ac_cv_file__dev_ptc=no
|
|
|
|
|
|
Cross compiling example::
|
|
|
|
CONFIG_SITE=config.site-aarch64 ../configure \
|
|
--build=x86_64-pc-linux-gnu \
|
|
--host=aarch64-unknown-linux-gnu \
|
|
--with-build-python=../x86_64/python
|
|
|
|
|
|
Python Build System
|
|
===================
|
|
|
|
Main files of the build system
|
|
------------------------------
|
|
|
|
* :file:`configure.ac` => :file:`configure`;
|
|
* :file:`Makefile.pre.in` => :file:`Makefile` (created by :file:`configure`);
|
|
* :file:`pyconfig.h` (created by :file:`configure`);
|
|
* :file:`Modules/Setup`: C extensions built by the Makefile using
|
|
:file:`Module/makesetup` shell script;
|
|
* :file:`setup.py`: C extensions built using the ``setuptools`` package.
|
|
|
|
Main build steps
|
|
----------------
|
|
|
|
* C files (``.c``) are built as object files (``.o``).
|
|
* A static ``libpython`` library (``.a``) is created from objects files.
|
|
* ``python.o`` and the static ``libpython`` library are linked into the
|
|
final ``python`` program.
|
|
* C extensions are built by the Makefile (see :file:`Modules/Setup`)
|
|
and ``python setup.py build``.
|
|
|
|
Main Makefile targets
|
|
---------------------
|
|
|
|
* ``make``: Build Python with the standard library.
|
|
* ``make platform:``: build the ``python`` program, but don't build the
|
|
standard library extension modules.
|
|
* ``make profile-opt``: build Python using Profile Guided Optimization (PGO).
|
|
You can use the configure :option:`--enable-optimizations` option to make
|
|
this the default target of the ``make`` command (``make all`` or just
|
|
``make``).
|
|
* ``make buildbottest``: Build Python and run the Python test suite, the same
|
|
way than buildbots test Python. Set ``TESTTIMEOUT`` variable (in seconds)
|
|
to change the test timeout (1200 by default: 20 minutes).
|
|
* ``make install``: Build and install Python.
|
|
* ``make regen-all``: Regenerate (almost) all generated files;
|
|
``make regen-stdlib-module-names`` and ``autoconf`` must be run separately
|
|
for the remaining generated files.
|
|
* ``make clean``: Remove built files.
|
|
* ``make distclean``: Same than ``make clean``, but remove also files created
|
|
by the configure script.
|
|
|
|
C extensions
|
|
------------
|
|
|
|
Some C extensions are built as built-in modules, like the ``sys`` module.
|
|
They are built with the ``Py_BUILD_CORE_BUILTIN`` macro defined.
|
|
Built-in modules have no ``__file__`` attribute::
|
|
|
|
>>> import sys
|
|
>>> sys
|
|
<module 'sys' (built-in)>
|
|
>>> sys.__file__
|
|
Traceback (most recent call last):
|
|
File "<stdin>", line 1, in <module>
|
|
AttributeError: module 'sys' has no attribute '__file__'
|
|
|
|
Other C extensions are built as dynamic libraries, like the ``_asyncio`` module.
|
|
They are built with the ``Py_BUILD_CORE_MODULE`` macro defined.
|
|
Example on Linux x86-64::
|
|
|
|
>>> import _asyncio
|
|
>>> _asyncio
|
|
<module '_asyncio' from '/usr/lib64/python3.9/lib-dynload/_asyncio.cpython-39-x86_64-linux-gnu.so'>
|
|
>>> _asyncio.__file__
|
|
'/usr/lib64/python3.9/lib-dynload/_asyncio.cpython-39-x86_64-linux-gnu.so'
|
|
|
|
:file:`Modules/Setup` is used to generate Makefile targets to build C extensions.
|
|
At the beginning of the files, C extensions are built as built-in modules.
|
|
Extensions defined after the ``*shared*`` marker are built as dynamic libraries.
|
|
|
|
The :file:`setup.py` script only builds C extensions as shared libraries using
|
|
the :mod:`distutils` module.
|
|
|
|
The :c:macro:`PyAPI_FUNC()`, :c:macro:`PyAPI_API()` and
|
|
:c:macro:`PyMODINIT_FUNC()` macros of :file:`Include/pyport.h` are defined
|
|
differently depending if the ``Py_BUILD_CORE_MODULE`` macro is defined:
|
|
|
|
* Use ``Py_EXPORTED_SYMBOL`` if the ``Py_BUILD_CORE_MODULE`` is defined
|
|
* Use ``Py_IMPORTED_SYMBOL`` otherwise.
|
|
|
|
If the ``Py_BUILD_CORE_BUILTIN`` macro is used by mistake on a C extension
|
|
built as a shared library, its ``PyInit_xxx()`` function is not exported,
|
|
causing an :exc:`ImportError` on import.
|
|
|
|
|
|
Compiler and linker flags
|
|
=========================
|
|
|
|
Options set by the ``./configure`` script and environment variables and used by
|
|
``Makefile``.
|
|
|
|
Preprocessor flags
|
|
------------------
|
|
|
|
.. envvar:: CONFIGURE_CPPFLAGS
|
|
|
|
Value of :envvar:`CPPFLAGS` variable passed to the ``./configure`` script.
|
|
|
|
.. versionadded:: 3.6
|
|
|
|
.. envvar:: CPPFLAGS
|
|
|
|
(Objective) C/C++ preprocessor flags, e.g. ``-I<include dir>`` if you have
|
|
headers in a nonstandard directory ``<include dir>``.
|
|
|
|
Both :envvar:`CPPFLAGS` and :envvar:`LDFLAGS` need to contain the shell's
|
|
value for setup.py to be able to build extension modules using the
|
|
directories specified in the environment variables.
|
|
|
|
.. envvar:: BASECPPFLAGS
|
|
|
|
.. versionadded:: 3.4
|
|
|
|
.. envvar:: PY_CPPFLAGS
|
|
|
|
Extra preprocessor flags added for building the interpreter object files.
|
|
|
|
Default: ``$(BASECPPFLAGS) -I. -I$(srcdir)/Include $(CONFIGURE_CPPFLAGS) $(CPPFLAGS)``.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
Compiler flags
|
|
--------------
|
|
|
|
.. envvar:: CC
|
|
|
|
C compiler command.
|
|
|
|
Example: ``gcc -pthread``.
|
|
|
|
.. envvar:: CXX
|
|
|
|
C++ compiler command.
|
|
|
|
Example: ``g++ -pthread``.
|
|
|
|
.. envvar:: CFLAGS
|
|
|
|
C compiler flags.
|
|
|
|
.. envvar:: CFLAGS_NODIST
|
|
|
|
:envvar:`CFLAGS_NODIST` is used for building the interpreter and stdlib C
|
|
extensions. Use it when a compiler flag should *not* be part of the
|
|
distutils :envvar:`CFLAGS` once Python is installed (:issue:`21121`).
|
|
|
|
In particular, :envvar:`CFLAGS` should not contain:
|
|
|
|
* the compiler flag ``-I`` (for setting the search path for include files).
|
|
The ``-I`` flags are processed from left to right, and any flags in
|
|
:envvar:`CFLAGS` would take precedence over user- and package-supplied ``-I``
|
|
flags.
|
|
|
|
* hardening flags such as ``-Werror`` because distributions cannot control
|
|
whether packages installed by users conform to such heightened
|
|
standards.
|
|
|
|
.. versionadded:: 3.5
|
|
|
|
.. envvar:: EXTRA_CFLAGS
|
|
|
|
Extra C compiler flags.
|
|
|
|
.. envvar:: CONFIGURE_CFLAGS
|
|
|
|
Value of :envvar:`CFLAGS` variable passed to the ``./configure``
|
|
script.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. envvar:: CONFIGURE_CFLAGS_NODIST
|
|
|
|
Value of :envvar:`CFLAGS_NODIST` variable passed to the ``./configure``
|
|
script.
|
|
|
|
.. versionadded:: 3.5
|
|
|
|
.. envvar:: BASECFLAGS
|
|
|
|
Base compiler flags.
|
|
|
|
.. envvar:: OPT
|
|
|
|
Optimization flags.
|
|
|
|
.. envvar:: CFLAGS_ALIASING
|
|
|
|
Strict or non-strict aliasing flags used to compile ``Python/dtoa.c``.
|
|
|
|
.. versionadded:: 3.7
|
|
|
|
.. envvar:: CCSHARED
|
|
|
|
Compiler flags used to build a shared library.
|
|
|
|
For example, ``-fPIC`` is used on Linux and on BSD.
|
|
|
|
.. envvar:: CFLAGSFORSHARED
|
|
|
|
Extra C flags added for building the interpreter object files.
|
|
|
|
Default: ``$(CCSHARED)`` when :option:`--enable-shared` is used, or an empty
|
|
string otherwise.
|
|
|
|
.. envvar:: PY_CFLAGS
|
|
|
|
Default: ``$(BASECFLAGS) $(OPT) $(CONFIGURE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS)``.
|
|
|
|
.. envvar:: PY_CFLAGS_NODIST
|
|
|
|
Default: ``$(CONFIGURE_CFLAGS_NODIST) $(CFLAGS_NODIST) -I$(srcdir)/Include/internal``.
|
|
|
|
.. versionadded:: 3.5
|
|
|
|
.. envvar:: PY_STDMODULE_CFLAGS
|
|
|
|
C flags used for building the interpreter object files.
|
|
|
|
Default: ``$(PY_CFLAGS) $(PY_CFLAGS_NODIST) $(PY_CPPFLAGS) $(CFLAGSFORSHARED)``.
|
|
|
|
.. versionadded:: 3.7
|
|
|
|
.. envvar:: PY_CORE_CFLAGS
|
|
|
|
Default: ``$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE``.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. envvar:: PY_BUILTIN_MODULE_CFLAGS
|
|
|
|
Compiler flags to build a standard library extension module as a built-in
|
|
module, like the :mod:`posix` module.
|
|
|
|
Default: ``$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE_BUILTIN``.
|
|
|
|
.. versionadded:: 3.8
|
|
|
|
.. envvar:: PURIFY
|
|
|
|
Purify command. Purify is a memory debugger program.
|
|
|
|
Default: empty string (not used).
|
|
|
|
|
|
Linker flags
|
|
------------
|
|
|
|
.. envvar:: LINKCC
|
|
|
|
Linker command used to build programs like ``python`` and ``_testembed``.
|
|
|
|
Default: ``$(PURIFY) $(CC)``.
|
|
|
|
.. envvar:: CONFIGURE_LDFLAGS
|
|
|
|
Value of :envvar:`LDFLAGS` variable passed to the ``./configure`` script.
|
|
|
|
Avoid assigning :envvar:`CFLAGS`, :envvar:`LDFLAGS`, etc. so users can use
|
|
them on the command line to append to these values without stomping the
|
|
pre-set values.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. envvar:: LDFLAGS_NODIST
|
|
|
|
:envvar:`LDFLAGS_NODIST` is used in the same manner as
|
|
:envvar:`CFLAGS_NODIST`. Use it when a linker flag should *not* be part of
|
|
the distutils :envvar:`LDFLAGS` once Python is installed (:issue:`35257`).
|
|
|
|
In particular, :envvar:`LDFLAGS` should not contain:
|
|
|
|
* the compiler flag ``-L`` (for setting the search path for libraries).
|
|
The ``-L`` flags are processed from left to right, and any flags in
|
|
:envvar:`LDFLAGS` would take precedence over user- and package-supplied ``-L``
|
|
flags.
|
|
|
|
.. envvar:: CONFIGURE_LDFLAGS_NODIST
|
|
|
|
Value of :envvar:`LDFLAGS_NODIST` variable passed to the ``./configure``
|
|
script.
|
|
|
|
.. versionadded:: 3.8
|
|
|
|
.. envvar:: LDFLAGS
|
|
|
|
Linker flags, e.g. ``-L<lib dir>`` if you have libraries in a nonstandard
|
|
directory ``<lib dir>``.
|
|
|
|
Both :envvar:`CPPFLAGS` and :envvar:`LDFLAGS` need to contain the shell's
|
|
value for setup.py to be able to build extension modules using the
|
|
directories specified in the environment variables.
|
|
|
|
.. envvar:: LIBS
|
|
|
|
Linker flags to pass libraries to the linker when linking the Python
|
|
executable.
|
|
|
|
Example: ``-lrt``.
|
|
|
|
.. envvar:: LDSHARED
|
|
|
|
Command to build a shared library.
|
|
|
|
Default: ``@LDSHARED@ $(PY_LDFLAGS)``.
|
|
|
|
.. envvar:: BLDSHARED
|
|
|
|
Command to build ``libpython`` shared library.
|
|
|
|
Default: ``@BLDSHARED@ $(PY_CORE_LDFLAGS)``.
|
|
|
|
.. envvar:: PY_LDFLAGS
|
|
|
|
Default: ``$(CONFIGURE_LDFLAGS) $(LDFLAGS)``.
|
|
|
|
.. envvar:: PY_LDFLAGS_NODIST
|
|
|
|
Default: ``$(CONFIGURE_LDFLAGS_NODIST) $(LDFLAGS_NODIST)``.
|
|
|
|
.. versionadded:: 3.8
|
|
|
|
.. envvar:: PY_CORE_LDFLAGS
|
|
|
|
Linker flags used for building the interpreter object files.
|
|
|
|
.. versionadded:: 3.8
|