3. 配置 Python ¶

3.1. 配置选项 ¶

列表所有 ./configure 脚本选项使用：

./configure --help

另请参阅 Misc/SpecialBuilds.txt 在 Python 源分发。

3.1.1. 一般选项 ¶

--enable-loadable-sqlite-extensions ¶

--disable-ipv6 ¶

--enable-big-digits =[15|30] ¶

--with-cxx-main ¶

--with-cxx-main =COMPILER ¶

--with-suffix =SUFFIX ¶

--with-tzpath =<list of absolute paths separated by pathsep> ¶

--without-decimal-contextvar ¶

--with-dbmliborder =<list of backend names> ¶

--without-c-locale-coercion ¶

--with-platlibdir =DIRNAME ¶

--with-wheel-pkg-dir =PATH ¶

--with-pkg-config =[check|yes|no] ¶

--enable-pystats ¶

--enable-wasm-dynamic-linking ¶

--enable-wasm-pthreads ¶

--enable-optimizations ¶

PROFILE_TASK ¶

--with-lto =[full|thin|no|yes] ¶

--with-computed-gotos ¶

--without-pymalloc ¶

--without-doc-strings ¶

--enable-profiling ¶

3.1.5. 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 模块。
添加 d to sys.abiflags .
添加 sys.gettotalrefcount() 函数。
添加 -X showrefcount 命令行选项。
添加 PYTHONTHREADDEBUG 环境变量。
Add support for the __lltrace__ variable: enable low-level tracing in the bytecode evaluation loop if the variable is defined.
安装 debug hooks on memory allocators to detect buffer overflow and other memory errors.
Define Py_DEBUG and Py_REF_DEBUG 宏。
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 --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.
- Py_SAFE_DOWNCAST() macro checks for integer underflow and overflow when downcasting from wide types to narrow types.

另请参阅 Python 开发模式和 --with-trace-refs configure option.

3.8 版改变：发行构建和调试构建现在兼容 ABI：定义的 Py_DEBUG 宏不再隐含 Py_TRACE_REFS macro (see the --with-trace-refs option), which introduces the only ABI incompatibility.

3.1.6. Debug options ¶

--with-pydebug ¶

--with-trace-refs ¶

--with-assertions ¶

--with-valgrind ¶

--with-dtrace ¶

--with-address-sanitizer ¶

--with-memory-sanitizer ¶

--with-undefined-behavior-sanitizer ¶

3.1.7. Linker options ¶

--enable-shared ¶

--without-static-libpython ¶

3.1.8. Libraries options ¶

--with-libs ='lib1 ...' ¶

--with-system-expat ¶

--with-system-ffi ¶

--with-system-libmpdec ¶

--with-readline =editline ¶

--without-readline ¶

--with-libm =STRING ¶

--with-libc =STRING ¶

--with-openssl =DIR ¶

--with-openssl-rpath =[no|auto|DIR] ¶

3.1.9. Security Options ¶

--with-hash-algorithm =[fnv|siphash13|siphash24] ¶

--with-builtin-hashlib-hashes =md5,sha1,sha256,sha512,sha3,blake2 ¶

--with-ssl-default-suites =[python|openssl|STRING] ¶

3.1.10. macOS Options ¶

见 Mac/README.rst .

--enable-universalsdk ¶

--enable-universalsdk =SDKDIR ¶

--enable-framework ¶

--enable-framework =INSTALLDIR ¶

--with-universal-archs =ARCH ¶

--with-framework-name =FRAMEWORK ¶

3.1.11. 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 ¶

--host =HOST ¶

--with-build-python =path/to/python ¶

CONFIG_SITE =file ¶

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

3.2. Python Build System ¶

3.2.1. Main files of the build system ¶

configure.ac => configure ;
Makefile.pre.in => Makefile (创建通过 configure );
pyconfig.h (创建通过 configure );
Modules/Setup : C extensions built by the Makefile using Module/makesetup shell script;
setup.py ：构建 C 扩展使用 distutils 模块。

3.2.2. 主要构建步骤 ¶

C 文件 ( .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 Modules/Setup ) 和 python setup.py build .

3.2.3. 主要 makefile 目标 ¶

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 --enable-optimizations option to make this the default target of the make 命令 ( 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.

3.2.4. C 扩展 ¶

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__ 属性：

>>> 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.

setup.py script only builds C extensions as shared libraries using the distutils 模块。

PyAPI_FUNC() , PyAPI_API() and PyMODINIT_FUNC() macros of Include/pyport.h are defined differently depending if the Py_BUILD_CORE_MODULE macro is defined:

使用 Py_EXPORTED_SYMBOL 若 Py_BUILD_CORE_MODULE is defined
使用 Py_IMPORTED_SYMBOL 否则。

若 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.

3.3. Compiler and linker flags ¶

Options set by the ./configure script and environment variables and used by Makefile .

3.3.1. Preprocessor flags ¶

CONFIGURE_CPPFLAGS ¶

CFLAGSFORSHARED ¶

Extra C flags added for building the interpreter object files.

默认： $(CCSHARED) 当 --enable-shared is used, or an empty string otherwise.

PY_CFLAGS ¶

PY_CFLAGS_NODIST ¶

PY_STDMODULE_CFLAGS ¶

C flags used for building the interpreter object files.

默认： $(PY_CFLAGS) $(PY_CFLAGS_NODIST) $(PY_CPPFLAGS) $(CFLAGSFORSHARED) .

3.7 版新增。

PY_CORE_CFLAGS ¶

PY_BUILTIN_MODULE_CFLAGS ¶

PURIFY ¶

Purify command. Purify is a memory debugger program.

Default: empty string (not used).

3.3.3. Linker flags ¶

LINKCC ¶