3. Configure Python¶
3.1. Build Requirements¶
Features and minimum versions required to build CPython:
A C11 compiler. Optional C11 features are not required.
On Windows, Microsoft Visual Studio 2017 or later is required.
Support for IEEE 754 floating-point numbers and floating-point Not-a-Number (NaN).
Support for threads.
OpenSSL 1.1.1 is the minimum version and OpenSSL 3.0.9 is the recommended minimum version for the
ssl
andhashlib
extension modules.SQLite 3.15.2 for the
sqlite3
extension module.Tcl/Tk 8.5.12 for the
tkinter
module.Autoconf 2.71 and aclocal 1.16.5 are required to regenerate the
configure
script.
Zmienione w wersji 3.1: Tcl/Tk version 8.3.1 is now required.
Zmienione w wersji 3.5: On Windows, Visual Studio 2015 or later is now required. Tcl/Tk version 8.4 is now required.
Zmienione w wersji 3.6: Selected C99 features are now required, like <stdint.h>
and static
inline
functions.
Zmienione w wersji 3.7: Thread support and OpenSSL 1.0.2 are now required.
Zmienione w wersji 3.10: OpenSSL 1.1.1 is now required. Require SQLite 3.7.15.
Zmienione w wersji 3.11: C11 compiler, IEEE 754 and NaN support are now required.
On Windows, Visual Studio 2017 or later is required.
Tcl/Tk version 8.5.12 is now required for the tkinter
module.
Zmienione w wersji 3.13: Autoconf 2.71, aclocal 1.16.5 and SQLite 3.15.2 are now required.
See also PEP 7 „Style Guide for C Code” and PEP 11 „CPython platform support”.
3.2. Generated files¶
To reduce build dependencies, Python source code contains multiple generated files. Commands to regenerate all generated files:
make regen-all
make regen-stdlib-module-names
make regen-limited-abi
make regen-configure
The Makefile.pre.in
file documents generated files, their inputs, and tools used
to regenerate them. Search for regen-*
make targets.
3.2.1. configure script¶
The make regen-configure
command regenerates the aclocal.m4
file and
the configure
script using the Tools/build/regen-configure.sh
shell
script which uses an Ubuntu container to get the same tools versions and have a
reproducible output.
The container is optional, the following command can be run locally:
autoreconf -ivf -Werror
The generated files can change depending on the exact autoconf-archive
,
aclocal
and pkg-config
versions.
3.3. Configure Options¶
List all configure
script options using:
./configure --help
See also the Misc/SpecialBuilds.txt
in the Python source distribution.
3.3.1. General Options¶
- --enable-loadable-sqlite-extensions¶
Support loadable extensions in the
_sqlite
extension module (default is no) of thesqlite3
module.See the
sqlite3.Connection.enable_load_extension()
method of thesqlite3
module.Added in version 3.6.
- --enable-big-digits=[15|30]¶
Define the size in bits of Python
int
digits: 15 or 30 bits.By default, the digit size is 30.
Define the
PYLONG_BITS_IN_DIGIT
to15
or30
.
- --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).Zmienione w wersji 3.11: The default suffix on WASM platform is one of
.js
,.html
or.wasm
.
- --with-tzpath=<list of absolute paths separated by pathsep>¶
Select the default time zone search path for
zoneinfo.TZPATH
. See the Compile-time configuration of thezoneinfo
module.Default:
/usr/share/zoneinfo:/usr/lib/zoneinfo:/usr/share/lib/zoneinfo:/etc/zoneinfo
.See
os.pathsep
path separator.Added in version 3.9.
- --without-decimal-contextvar¶
Build the
_decimal
extension module using a thread-local context rather than a coroutine-local context (default), see thedecimal
module.See
decimal.HAVE_CONTEXTVAR
and thecontextvars
module.Added in version 3.9.
- --with-dbmliborder=<list of backend names>¶
Override order to check db backends for the
dbm
moduleA valid value is a colon (
:
) separated string with the backend names:ndbm
;gdbm
;bdb
.
- --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
PYTHONCOERCECLOCALE
and the PEP 538.
- --without-freelists¶
Disable all freelists except the empty tuple singleton.
Added in version 3.11.
- --with-platlibdir=DIRNAME¶
Python library directory name (default is
lib
).Fedora and SuSE use
lib64
on 64-bit platforms.See
sys.platlibdir
.Added in version 3.9.
- --with-wheel-pkg-dir=PATH¶
Directory of wheel packages used by the
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 theensurepip._bundled
package.Added in version 3.10.
- --with-pkg-config=[check|yes|no]¶
Whether configure should use pkg-config to detect build dependencies.
check
(default): pkg-config is optionalyes
: pkg-config is mandatoryno
: configure does not use pkg-config even when present
Added in version 3.11.
- --enable-pystats¶
Turn on internal Python performance statistics gathering.
By default, statistics gathering is off. Use
python3 -X pystats
command or setPYTHONSTATS=1
environment variable to turn on statistics gathering at Python startup.At Python exit, dump statistics if statistics gathering was on and not cleared.
Effects:
Add
-X pystats
command line option.Add
PYTHONSTATS
environment variable.Define the
Py_STATS
macro.Add functions to the
sys
module:sys._stats_on()
: Turns on statistics gathering.sys._stats_off()
: Turns off statistics gathering.sys._stats_clear()
: Clears the statistics.sys._stats_dump()
: Dump statistics to file, and clears the statistics.
The statistics will be dumped to a arbitrary (probably unique) file in
/tmp/py_stats/
(Unix) orC:\temp\py_stats\
(Windows). If that directory does not exist, results will be printed on stderr.Use
Tools/scripts/summarize_stats.py
to read the stats.Statistics:
Opcode:
Specialization: success, failure, hit, deferred, miss, deopt, failures;
Execution count;
Pair count.
Call:
Inlined Python calls;
PyEval calls;
Frames pushed;
Frame object created;
Eval calls: vector, generator, legacy, function VECTORCALL, build class, slot, function „ex”, API, method.
Object:
incref and decref;
interpreter incref and decref;
allocations: all, 512 bytes, 4 kiB, big;
free;
to/from free lists;
dictionary materialized/dematerialized;
type cache;
optimization attempts;
optimization traces created/executed;
uops executed.
Garbage collector:
Garbage collections;
Objects visited;
Objects collected.
Added in version 3.11.
- --disable-gil¶
Enables experimental support for running Python without the global interpreter lock (GIL): free threading build.
Defines the
Py_GIL_DISABLED
macro and adds"t"
tosys.abiflags
.See Free-threaded CPython for more detail.
Added in version 3.13.
- PKG_CONFIG¶
Path to
pkg-config
utility.
- PKG_CONFIG_LIBDIR¶
- PKG_CONFIG_PATH¶
pkg-config
options.
3.3.2. C compiler options¶
- CC¶
C compiler command.
- CFLAGS¶
C compiler flags.
- CPP¶
C preprocessor command.
- CPPFLAGS¶
C preprocessor flags, e.g.
-Iinclude_dir
.
3.3.3. Linker options¶
- LDFLAGS¶
Linker flags, e.g.
-Llibrary_directory
.
- LIBS¶
Libraries to pass to the linker, e.g.
-llibrary
.
- MACHDEP¶
Name for machine-dependent library files.
3.3.4. Options for third-party dependencies¶
Added in version 3.11.
- BZIP2_CFLAGS¶
- BZIP2_LIBS¶
C compiler and linker flags to link Python to
libbz2
, used bybz2
module, overridingpkg-config
.
- CURSES_CFLAGS¶
- CURSES_LIBS¶
C compiler and linker flags for
libncurses
orlibncursesw
, used bycurses
module, overridingpkg-config
.
- GDBM_CFLAGS¶
- GDBM_LIBS¶
C compiler and linker flags for
gdbm
.
- LIBB2_CFLAGS¶
- LIBB2_LIBS¶
C compiler and linker flags for
libb2
(BLAKE2), used byhashlib
module, overridingpkg-config
.
- LIBEDIT_CFLAGS¶
- LIBEDIT_LIBS¶
C compiler and linker flags for
libedit
, used byreadline
module, overridingpkg-config
.
- LIBFFI_CFLAGS¶
- LIBMPDEC_CFLAGS¶
- LIBMPDEC_LIBS¶
C compiler and linker flags for
libmpdec
, used bydecimal
module, overridingpkg-config
.Informacja
These environment variables have no effect unless
--with-system-libmpdec
is specified.
- LIBLZMA_CFLAGS¶
- LIBREADLINE_CFLAGS¶
- LIBREADLINE_LIBS¶
C compiler and linker flags for
libreadline
, used byreadline
module, overridingpkg-config
.
- LIBSQLITE3_CFLAGS¶
- LIBSQLITE3_LIBS¶
C compiler and linker flags for
libsqlite3
, used bysqlite3
module, overridingpkg-config
.
- LIBUUID_CFLAGS¶
- PANEL_CFLAGS¶
- PANEL_LIBS¶
C compiler and linker flags for PANEL, overriding
pkg-config
.C compiler and linker flags for
libpanel
orlibpanelw
, used bycurses.panel
module, overridingpkg-config
.
- TCLTK_CFLAGS¶
- TCLTK_LIBS¶
C compiler and linker flags for TCLTK, overriding
pkg-config
.
- ZLIB_CFLAGS¶
3.3.5. WebAssembly Options¶
- --with-emscripten-target=[browser|node]¶
Set build flavor for
wasm32-emscripten
.browser
(default): preload minimal stdlib, default MEMFS.node
: NODERAWFS and pthread support.
Added in version 3.11.
- --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.Added in version 3.11.
- --enable-wasm-pthreads¶
Turn on pthreads support for WASM.
Added in version 3.11.
3.3.6. Install Options¶
- --prefix=PREFIX¶
Install architecture-independent files in PREFIX. On Unix, it defaults to
/usr/local
.This value can be retrieved at runtime using
sys.prefix
.As an example, one can use
--prefix="$HOME/.local/"
to install a Python in its home directory.
- --exec-prefix=EPREFIX¶
Install architecture-dependent files in EPREFIX, defaults to
--prefix
.This value can be retrieved at runtime using
sys.exec_prefix
.
3.3.7. Performance options¶
Configuring Python using --enable-optimizations --with-lto
(PGO + LTO) is
recommended for best performance. The experimental --enable-bolt
flag can
also be used to improve performance.
- --enable-optimizations¶
Enable Profile Guided Optimization (PGO) using
PROFILE_TASK
(disabled by default).The C compiler Clang requires
llvm-profdata
program for PGO. On macOS, GCC also requires it: GCC is just an alias to Clang on macOS.Disable also semantic interposition in libpython if
--enable-shared
and GCC is used: add-fno-semantic-interposition
to the compiler and linker flags.Informacja
During the build, you may encounter compiler warnings about profile data not being available for some source files. These warnings are harmless, as only a subset of the code is exercised during profile data acquisition. To disable these warnings on Clang, manually suppress them by adding
-Wno-profile-instr-unprofiled
toCFLAGS
.Added in version 3.6.
Zmienione w wersji 3.10: Use
-fno-semantic-interposition
on GCC.
- PROFILE_TASK¶
Environment variable used in the Makefile: Python command line arguments for the PGO generation task.
Default:
-m test --pgo --timeout=$(TESTTIMEOUT)
.Added in version 3.8.
Zmienione w wersji 3.13: Task failure is no longer ignored silently.
- --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
orlld
).Added in version 3.6.
Added in version 3.11: To use ThinLTO feature, use
--with-lto=thin
on Clang.Zmienione w wersji 3.12: Use ThinLTO as the default optimization policy on Clang if the compiler accepts the flag.
- --enable-bolt¶
Enable usage of the BOLT post-link binary optimizer (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
andmerge-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. BOLT versions before LLVM 16 are known to crash BOLT under some scenarios. Use of LLVM 16 or newer for BOLT optimization is strongly encouraged.
The
BOLT_INSTRUMENT_FLAGS
andBOLT_APPLY_FLAGS
configure variables can be defined to override the default set of arguments for llvm-bolt to instrument and apply BOLT data to binaries, respectively.Added in version 3.12.
- BOLT_APPLY_FLAGS¶
Arguments to
llvm-bolt
when creating a BOLT optimized binary.Added in version 3.12.
- BOLT_INSTRUMENT_FLAGS¶
Arguments to
llvm-bolt
when instrumenting binaries.Added in version 3.12.
- --with-computed-gotos¶
Enable computed gotos in evaluation loop (enabled by default on supported compilers).
- --without-mimalloc¶
Disable the fast mimalloc allocator (enabled by default).
See also
PYTHONMALLOC
environment variable.
- --without-pymalloc¶
Disable the specialized Python memory allocator pymalloc (enabled by default).
See also
PYTHONMALLOC
environment variable.
- --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.
- --enable-profiling¶
Enable C-level code profiling with
gprof
(disabled by default).
- --with-strict-overflow¶
Add
-fstrict-overflow
to the C compiler flags (by default we add-fno-strict-overflow
instead).
3.3.8. Python Debug Build¶
A debug build is Python built with the --with-pydebug
configure
option.
Effects of a debug build:
Display all warnings by default: the list of default warning filters is empty in the
warnings
module.Add
d
tosys.abiflags
.Add
sys.gettotalrefcount()
function.Add
-X showrefcount
command line option.Add
-d
command line option andPYTHONDEBUG
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 debug hooks on memory allocators to detect buffer overflow and other memory errors.
Define
Py_DEBUG
andPy_REF_DEBUG
macros.Add runtime checks: code surrounded by
#ifdef Py_DEBUG
and#endif
. Enableassert(...)
and_PyObject_ASSERT(...)
assertions: don’t set theNDEBUG
macro (see also the--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 (
gc.collect()
function) runs some basic checks on objects consistency.The
Py_SAFE_DOWNCAST()
macro checks for integer underflow and overflow when downcasting from wide types to narrow types.
See also the Python Development Mode and the
--with-trace-refs
configure option.
Zmienione w wersji 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
--with-trace-refs
option).
3.3.9. Debug options¶
- --with-pydebug¶
Build Python in debug mode: define the
Py_DEBUG
macro (disabled by default).
- --with-trace-refs¶
Enable tracing references for debugging purpose (disabled by default).
Effects:
Define the
Py_TRACE_REFS
macro.Add
sys.getobjects()
function.Add
PYTHONDUMPREFS
environment variable.
The
PYTHONDUMPREFS
environment variable can be used to dump objects and reference counts still alive at Python exit.Statically allocated objects are not traced.
Added in version 3.8.
Zmienione w wersji 3.13: This build is now ABI compatible with release build and debug build.
- --with-assertions¶
Build with C assertions enabled (default is no):
assert(...);
and_PyObject_ASSERT(...);
.If set, the
NDEBUG
macro is not defined in theOPT
compiler variable.See also the
--with-pydebug
option (debug build) which also enables assertions.Added in version 3.6.
- --with-valgrind¶
Enable Valgrind support (default is no).
- --with-dtrace¶
Enable DTrace support (default is no).
See Instrumenting CPython with DTrace and SystemTap.
Added in version 3.6.
- --with-address-sanitizer¶
Enable AddressSanitizer memory error detector,
asan
(default is no).Added in version 3.6.
- --with-memory-sanitizer¶
Enable MemorySanitizer allocation error detector,
msan
(default is no).Added in version 3.6.
- --with-undefined-behavior-sanitizer¶
Enable UndefinedBehaviorSanitizer undefined behaviour detector,
ubsan
(default is no).Added in version 3.6.
- --with-thread-sanitizer¶
Enable ThreadSanitizer data race detector,
tsan
(default is no).Added in version 3.13.
3.3.10. Linker options¶
Enable building a shared Python library:
libpython
(default is no).
- --without-static-libpython¶
Do not build
libpythonMAJOR.MINOR.a
and do not installpython.o
(built and enabled by default).Added in version 3.10.
3.3.11. Libraries options¶
- --with-libs='lib1 ...'¶
Link against additional libraries (default is no).
- --with-system-expat¶
Build the
pyexpat
module using an installedexpat
library (default is no).
- --with-system-libmpdec¶
Build the
_decimal
extension module using an installedmpdecimal
library, see thedecimal
module (default is yes).Added in version 3.3.
Zmienione w wersji 3.13: Default to using the installed
mpdecimal
library.Deprecated since version 3.13, will be removed in version 3.15: A copy of the
mpdecimal
library sources will no longer be distributed with Python 3.15.Zobacz także
- --with-readline=readline|editline¶
Designate a backend library for the
readline
module.readline: Use readline as the backend.
editline: Use editline as the backend.
Added in version 3.10.
- --without-readline¶
Don’t build the
readline
module (built by default).Don’t define the
HAVE_LIBREADLINE
macro.Added in version 3.10.
- --with-libm=STRING¶
Override
libm
math library to STRING (default is system-dependent).
- --with-libc=STRING¶
Override
libc
C library to STRING (default is system-dependent).
- --with-openssl=DIR¶
Root of the OpenSSL directory.
Added in version 3.7.
- --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--with-openssl
andpkg-config
;DIR: set an explicit rpath.
Added in version 3.10.
3.3.12. Security Options¶
- --with-hash-algorithm=[fnv|siphash13|siphash24]¶
Select hash algorithm for use in
Python/pyhash.c
:siphash13
(default);siphash24
;fnv
.
Added in version 3.4.
Added in version 3.11:
siphash13
is added and it is the new default.
- --with-builtin-hashlib-hashes=md5,sha1,sha256,sha512,sha3,blake2¶
Built-in hash modules:
md5
;sha1
;sha256
;sha512
;sha3
(with shake);blake2
.
Added in version 3.9.
- --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
ssl
module.Added in version 3.7.
Zmienione w wersji 3.10: The settings
python
and STRING also set TLS 1.2 as minimum protocol version.
3.3.13. macOS Options¶
See Mac/README.rst.
- --enable-universalsdk¶
- --enable-universalsdk=SDKDIR¶
Create a universal binary build. SDKDIR specifies which macOS SDK should be used to perform the build (default is no).
- --enable-framework¶
- --enable-framework=INSTALLDIR¶
Create a Python.framework rather than a traditional Unix install. Optional INSTALLDIR specifies the installation path (default is no).
- --with-universal-archs=ARCH¶
Specify the kind of universal binary that should be created. This option is only valid when
--enable-universalsdk
is set.Options:
universal2
;32-bit
;64-bit
;3-way
;intel
;intel-32
;intel-64
;all
.
- --with-framework-name=FRAMEWORK¶
Specify the name for the python framework on macOS only valid when
--enable-framework
is set (default:Python
).
- --with-app-store-compliance¶
- --with-app-store-compliance=PATCH-FILE¶
The Python standard library contains strings that are known to trigger automated inspection tool errors when submitted for distribution by the macOS and iOS App Stores. If enabled, this option will apply the list of patches that are known to correct app store compliance. A custom patch file can also be specified. This option is disabled by default.
Added in version 3.13.
3.3.14. iOS Options¶
See iOS/README.rst.
- --enable-framework=INSTALLDIR¶
Create a Python.framework. Unlike macOS, the INSTALLDIR argument specifying the installation path is mandatory.
- --with-framework-name=FRAMEWORK¶
Specify the name for the framework (default:
Python
).
3.3.15. 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.
- --build=BUILD¶
configure for building on BUILD, usually guessed by config.guess.
- --host=HOST¶
cross-compile to build programs to run on HOST (target platform)
- --with-build-python=path/to/python¶
path to build
python
binary for cross compilingAdded in version 3.11.
- 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
- HOSTRUNNER¶
Program to run CPython for the host platform for cross-compilation.
Added in version 3.11.
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
3.4. Python Build System¶
3.4.1. Main files of the build system¶
configure.ac
=>configure
;Makefile.pre.in
=>Makefile
(created byconfigure
);pyconfig.h
(created byconfigure
);Modules/Setup
: C extensions built by the Makefile usingModule/makesetup
shell script;
3.4.2. 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 staticlibpython
library are linked into the finalpython
program.C extensions are built by the Makefile (see
Modules/Setup
).
3.4.3. Main Makefile targets¶
3.4.3.1. make¶
For the most part, when rebuilding after editing some code or
refreshing your checkout from upstream, all you need to do is execute
make
, which (per Make’s semantics) builds the default target, the
first one defined in the Makefile. By tradition (including in the
CPython project) this is usually the all
target. The
configure
script expands an autoconf
variable,
@DEF_MAKE_ALL_RULE@
to describe precisely which targets make
all
will build. The three choices are:
profile-opt
(configured with--enable-optimizations
)build_wasm
(configured with--with-emscripten-target
)build_all
(configured without explicitly using either of the others)
Depending on the most recent source file changes, Make will rebuild
any targets (object files and executables) deemed out-of-date,
including running configure
again if necessary. Source/target
dependencies are many and maintained manually however, so Make
sometimes doesn’t have all the information necessary to correctly
detect all targets which need to be rebuilt. Depending on which
targets aren’t rebuilt, you might experience a number of problems. If
you have build or test problems which you can’t otherwise explain,
make clean && make
should work around most dependency problems, at
the expense of longer build times.
3.4.3.2. make platform¶
Build the python
program, but don’t build the standard library
extension modules. This generates a file named platform
which
contains a single line describing the details of the build platform,
e.g., macosx-14.3-arm64-3.12
or linux-x86_64-3.13
.
3.4.3.3. make profile-opt¶
Build Python using profile-guided optimization (PGO). You can use the
configure --enable-optimizations
option to make this the
default target of the make
command (make all
or just
make
).
3.4.3.4. make clean¶
Remove built files.
3.4.3.5. make distclean¶
In addition to the work done by make clean
, remove files
created by the configure script. configure
will have to be run
before building again. [1]
3.4.3.6. make install¶
Build the all
target and install Python.
3.4.3.7. make test¶
Build the all
target and run the Python test suite with the
--fast-ci
option. Variables:
TESTOPTS
: additional regrtest command-line options.TESTPYTHONOPTS
: additional Python command-line options.TESTTIMEOUT
: timeout in seconds (default: 10 minutes).
3.4.3.8. make buildbottest¶
This is similar to make test
, but uses the --slow-ci
option and default timeout of 20 minutes, instead of --fast-ci
option.
3.4.3.9. make regen-all¶
Regenerate (almost) all generated files. These include (but are not
limited to) bytecode cases, and parser generator file.
make regen-stdlib-module-names
and autoconf
must be run
separately for the remaining generated files.
3.4.4. 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'
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 PyAPI_FUNC()
, PyAPI_DATA()
and
PyMODINIT_FUNC
macros of Include/exports.h
are defined
differently depending if the Py_BUILD_CORE_MODULE
macro is defined:
Use
Py_EXPORTED_SYMBOL
if thePy_BUILD_CORE_MODULE
is definedUse
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 ImportError
on import.
3.5. Compiler and linker flags¶
Options set by the ./configure
script and environment variables and used by
Makefile
.
3.5.1. Preprocessor flags¶
- CONFIGURE_CPPFLAGS¶
Value of
CPPFLAGS
variable passed to the./configure
script.Added in version 3.6.
- CPPFLAGS¶
(Objective) C/C++ preprocessor flags, e.g.
-Iinclude_dir
if you have headers in a nonstandard directory include_dir.Both
CPPFLAGS
andLDFLAGS
need to contain the shell’s value to be able to build extension modules using the directories specified in the environment variables.
- BASECPPFLAGS¶
Added in version 3.4.
- PY_CPPFLAGS¶
Extra preprocessor flags added for building the interpreter object files.
Default:
$(BASECPPFLAGS) -I. -I$(srcdir)/Include $(CONFIGURE_CPPFLAGS) $(CPPFLAGS)
.Added in version 3.2.
3.5.2. Compiler flags¶
- CC¶
C compiler command.
Example:
gcc -pthread
.
- CXX¶
C++ compiler command.
Example:
g++ -pthread
.
- CFLAGS¶
C compiler flags.
- CFLAGS_NODIST¶
CFLAGS_NODIST
is used for building the interpreter and stdlib C extensions. Use it when a compiler flag should not be part ofCFLAGS
once Python is installed (gh-65320).In particular,
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 inCFLAGS
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.
Added in version 3.5.
- COMPILEALL_OPTS¶
Options passed to the
compileall
command line when building PYC files inmake install
. Default:-j0
.Added in version 3.12.
- EXTRA_CFLAGS¶
Extra C compiler flags.
- CONFIGURE_CFLAGS_NODIST¶
Value of
CFLAGS_NODIST
variable passed to the./configure
script.Added in version 3.5.
- BASECFLAGS¶
Base compiler flags.
- OPT¶
Optimization flags.
- CFLAGS_ALIASING¶
Strict or non-strict aliasing flags used to compile
Python/dtoa.c
.Added in version 3.7.
- CCSHARED¶
Compiler flags used to build a shared library.
For example,
-fPIC
is used on Linux and on BSD.
- CFLAGSFORSHARED¶
Extra C flags added for building the interpreter object files.
Default:
$(CCSHARED)
when--enable-shared
is used, or an empty string otherwise.
- PY_CFLAGS¶
Default:
$(BASECFLAGS) $(OPT) $(CONFIGURE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS)
.
- PY_CFLAGS_NODIST¶
Default:
$(CONFIGURE_CFLAGS_NODIST) $(CFLAGS_NODIST) -I$(srcdir)/Include/internal
.Added in version 3.5.
- PY_STDMODULE_CFLAGS¶
C flags used for building the interpreter object files.
Default:
$(PY_CFLAGS) $(PY_CFLAGS_NODIST) $(PY_CPPFLAGS) $(CFLAGSFORSHARED)
.Added in version 3.7.
- PY_CORE_CFLAGS¶
Default:
$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE
.Added in version 3.2.
- PY_BUILTIN_MODULE_CFLAGS¶
Compiler flags to build a standard library extension module as a built-in module, like the
posix
module.Default:
$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE_BUILTIN
.Added in version 3.8.
- PURIFY¶
Purify command. Purify is a memory debugger program.
Default: empty string (not used).
3.5.3. Linker flags¶
- LINKCC¶
Linker command used to build programs like
python
and_testembed
.Default:
$(PURIFY) $(CC)
.
- CONFIGURE_LDFLAGS¶
Value of
LDFLAGS
variable passed to the./configure
script.Avoid assigning
CFLAGS
,LDFLAGS
, etc. so users can use them on the command line to append to these values without stomping the pre-set values.Added in version 3.2.
- LDFLAGS_NODIST¶
LDFLAGS_NODIST
is used in the same manner asCFLAGS_NODIST
. Use it when a linker flag should not be part ofLDFLAGS
once Python is installed (gh-65320).In particular,
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 inLDFLAGS
would take precedence over user- and package-supplied-L
flags.
- CONFIGURE_LDFLAGS_NODIST¶
Value of
LDFLAGS_NODIST
variable passed to the./configure
script.Added in version 3.8.
- LDFLAGS¶
Linker flags, e.g.
-Llib_dir
if you have libraries in a nonstandard directory lib_dir.Both
CPPFLAGS
andLDFLAGS
need to contain the shell’s value to be able to build extension modules using the directories specified in the environment variables.
- LIBS¶
Linker flags to pass libraries to the linker when linking the Python executable.
Example:
-lrt
.
- LDSHARED¶
Command to build a shared library.
Default:
@LDSHARED@ $(PY_LDFLAGS)
.
- BLDSHARED¶
Command to build
libpython
shared library.Default:
@BLDSHARED@ $(PY_CORE_LDFLAGS)
.
- PY_LDFLAGS¶
Default:
$(CONFIGURE_LDFLAGS) $(LDFLAGS)
.
- PY_LDFLAGS_NODIST¶
Default:
$(CONFIGURE_LDFLAGS_NODIST) $(LDFLAGS_NODIST)
.Added in version 3.8.
- PY_CORE_LDFLAGS¶
Linker flags used for building the interpreter object files.
Added in version 3.8.
Footnotes