Hi Inada-san, You can query the sysconfig module to check how Python has been built. Example: pyvstinner@apu$ python3 Python 3.7.4 (default, Jul 9 2019, 16:32:37) [GCC 9.1.1 20190503 (Red Hat 9.1.1-1)] on linux Type "help", "copyright", "credits" or "license" for more information.

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import sysconfig

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sysconfig.get_config_var('PY_CFLAGS') '-Wno-unused-result -Wsign-compare -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -D_GNU_SOURCE -fPIC -fwrapv'

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sysconfig.get_config_var('PY_CFLAGS_NODIST') '-O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -D_GNU_SOURCE -fPIC -fwrapv -flto -fuse-linker-plugin -ffat-lto-objects -flto-partition=none -g -std=c99 -Wextra -Wno-unused-result -Wno-unused-parameter -Wno-missing-field-initializers -Wno-cast-function-type -Werror=implicit-function-declaration -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -D_GNU_SOURCE -fPIC -fwrapv -fprofile-use -fprofile-correction'

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sysconfig.get_config_var('PY_LDFLAGS') '-Wl,-z,relro -Wl,--as-needed -Wl,-z,now -g'

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sysconfig.get_config_var('PY_LDFLAGS_NODIST') '-Wl,-z,relro -Wl,--as-needed -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -g -flto -fuse-linker-plugin -ffat-lto-objects -flto-partition=none -g'

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import shlex [opt for opt in shlex.split(sysconfig.get_config_var('PY_CFLAGS') + sysconfig.get_config_var('PY_CFLAGS_NODIST')) if opt.startswith('-O') or 'profile' in opt] ['-O2', '-O2', '-fprofile-use', '-fprofile-correction']

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[opt for opt in shlex.split(sysconfig.get_config_var('PY_LDFLAGS') + sysconfig.get_config_var('PY_LDFLAGS_NODIST')) if 'lto' in opt] ['-flto', '-ffat-lto-objects', '-flto-partition=none']

You can see that Fedora 30 /usr/bin/python3.7 is built using -O2 and has been optimized with PGO (compiler flag -fprofile-use) and LTO (linker flag -flto). Victor Le mar. 15 oct. 2019 à 11:02, Inada Naoki a écrit :

Hi, all.

I want Homebrew uses `--enable-optimizations` and `--with-lto` option for building Python. But maintainer said:

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Given this is not a default option, probably not, unless it is done in upstream (“official”) binaries.

https://github.com/Homebrew/homebrew-core/pull/45337

Are these options used for official macOS binaries? Is there official information about the build step of official binaries?

Regards, -- Inada Naoki _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-leave@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/EILILECN... Code of Conduct: http://python.org/psf/codeofconduct/

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Thank you for your response. And I'm sorry about ignoring this. Gmail marked it as spam. On Tue, Oct 15, 2019 at 6:20 PM Ned Deily wrote:

We currently do not use those options to build the binaries for the python.org macOS installers. The main reason is that the Pythons we provide are built to support a wide-range of macOS releases and to do so safely we build the binaries on the oldest version of macOS supported by that installer. So, for example, the 10.9+ installer variant is built on a 10.9 system. Some of the optimization features either aren't available or are less robust on older build tools.

It makes sense.

And I believe it is more important for the python.org macOS installers to continue to provide a single installer that is usable on many systems and can be used in a broad range of applications and by a broad range of users rather than trying to optimize performance for a specific application: you can always build your own Python.

As far as what other distributors of Python for macOS do, what we do shouldn't necessarily constrain them. I don't see any problem with Homebrew optimizing for a particular user's installation. I see that MacPorts, another distributor of Python on macOS, provides a non-default variant that uses --enable-optimizations.

https://github.com/macports/macports-ports/blob/master/lang/python37/Portfil...

-- Ned Deily nad@python.org -- []

-- Inada Naoki