gh-146636: Improve ABI/feature selection, add new header for it#148302
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encukou wants to merge 6 commits intopython:mainfrom
Open
gh-146636: Improve ABI/feature selection, add new header for it#148302encukou wants to merge 6 commits intopython:mainfrom
encukou wants to merge 6 commits intopython:mainfrom
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…ABLED Add a test that Python headers themselves don't use Py_GIL_DISABLED in abi3t: abi3 and abi3t ought to be the same except the _Py_OPAQUE_PYOBJECT differences. This is done using the GCC-only poison pragma.
encukou
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vstinner
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Apr 9, 2026
| # define Py_GIL_DISABLED | ||
| # endif | ||
| # if defined(_Py_IS_TESTCEXT) | ||
| // When compiling for abi3t, contents of Python.h should not depend |
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Suggested change
| // When compiling for abi3t, contents of Python.h should not depend | |
| // When compiling for abi3t, contents of Python.h should not depend |
| // whether they need extra synchronization. | ||
| # define Py_GIL_DISABLED | ||
| # endif | ||
| # if defined(_Py_IS_TESTCEXT) |
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You may move #ifdef __GNUC__ here:
Suggested change
| # if defined(_Py_IS_TESTCEXT) | |
| # if defined(_Py_IS_TESTCEXT) && defined(__GNUC__) |
| // on Py_GIL_DISABLED. | ||
| // We ask GCC to error if it sees the macro from this point on. | ||
| // Since users are free to the macro, and there's no way to undo the | ||
| // poisoning at the end of Python.h, we only do this in a test module. |
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You may mention test_cext explicitly:
Suggested change
| // poisoning at the end of Python.h, we only do this in a test module. | |
| // poisoning at the end of Python.h, we only do this in a test module | |
| // (test_cext). |
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| /* The internal C API must not be used with the limited C API: make sure | ||
| * that Py_BUILD_CORE* macros are not defined in this case. | ||
| * But, keep the "original" values, under different names, for "exports.h" |
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It's surprising that _PyEXPORTS_CORE and _PyEXPORTS_CORE_MODULE are defined even if Py_LIMITED_API is defined. I tried to undefine Py_BUILD_CORE if Py_LIMITED_API is defined before _PyEXPORTS_CORE code, but I got linker errors on Windows. Examples:
LINK : warning LNK4217: symbol 'PyType_GetFlags' defined in 'typeobject.obj' is imported by '_stat.obj' in fu
nction '_PyLong_AsMode_t' [C:\victor\python\main\PCbuild\pythoncore.vcxproj]
LINK : warning LNK4217: symbol '_Py_DecRef' defined in 'object.obj' is imported by '_stat.obj' in function '_
PyLong_AsMode_t' [C:\victor\python\main\PCbuild\pythoncore.vcxproj]
LINK : warning LNK4286: symbol '_Py_DecRef' defined in 'object.obj' is imported by 'errnomodule.obj' [C:\vict
or\python\main\PCbuild\pythoncore.vcxproj]
LINK : warning LNK4217: symbol 'PyUnicode_FromStringAndSize' defined in 'unicodeobject.obj' is imported by '_
stat.obj' in function 'stat_filemode' [C:\victor\python\main\PCbuild\pythoncore.vcxproj]
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Feature/ABI selection headers (Py_BUILD_CORE, Py_LIMITED_API, Py_GIL_DISABLED) need to be defined early (so they affect all definitions), but after the version (
patchlevel.h) and configuration (pyconfig.h).Put them in their own header to make this more obvious, and easier for contributors to keep them in the proper place.
Add a test that Python headers themselves don't use Py_GIL_DISABLED, since abi3 and abi3t ought to be identical except for the _Py_OPAQUE_PYOBJECT differences.
This is done using the GCC-only poison pragma, which tells the compiler/preprocessor to error if it ever sees the identifier after the pragma.
This needs some rewriting:
#if defined(Py_LIMITED_API) && defined(Py_GIL_DISABLED)needs to be split into two lines, as the poisoning doesn't honour short-circuiting.This should fix gh-148267, but I'm attaching the PR to the abi3t issue, gh-146636, as it continues that effort (GH-148142 specifically).