From a3d39e86c640ef441ac919aefaec6a670beacb0b Mon Sep 17 00:00:00 2001 From: Bryan Green Date: Fri, 2 Jan 2026 10:48:54 -0600 Subject: [PATCH v2] Enable Python Limited API for PL/Python on MSVC Previously, the Python Limited API was disabled on MSVC due to build failures caused by Meson not knowing to link against python3.lib instead of python3XX.lib when using the Limited API. This commit works around the Meson limitation by explicitly finding and linking against python3.lib on MSVC, and removes the preprocessor guard that was disabling the Limited API on MSVC in plpython.h. This requires python3.lib to be present in the Python installation, which is included when Python is installed. Discussion: https://www.postgresql.org/message-id/flat/ee410de1-1e0b-4770-b125-eeefd4726a24%40eisentraut.org --- meson.build | 21 +++++++++++++++++++-- src/pl/plpython/plpython.h | 4 ---- 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/meson.build b/meson.build index d7c5193d4c..4b45732d53 100644 --- a/meson.build +++ b/meson.build @@ -1329,9 +1329,26 @@ if not pyopt.disabled() pm = import('python') python3_inst = pm.find_installation(python.full_path(), required: pyopt) if python3_inst.found() - python3_dep = python3_inst.dependency(embed: true, required: pyopt) + # For Limited API on MSVC, link against python3.lib instead of python3XX.lib. + # Meson doesn't handle this automatically: + # + if host_system == 'windows' and cc.get_id() == 'msvc' + python3_prefix = python3_inst.get_variable('prefix') + python3_libdir = python3_prefix / 'libs' + python3_incdir = python3_prefix / 'include' + python3_lib = cc.find_library('python3', dirs: python3_libdir, required: pyopt) + python3_dep = declare_dependency( + include_directories: include_directories(python3_incdir), + dependencies: python3_lib, + ) + # Explicit args needed for older Meson compatibility + python3_header_check_args = ['/I' + python3_incdir] + else + python3_dep = python3_inst.dependency(embed: true, required: pyopt) + python3_header_check_args = [] + endif # Remove this check after we depend on Meson >= 1.1.0 - if not cc.check_header('Python.h', dependencies: python3_dep, required: pyopt, include_directories: postgres_inc) + if not cc.check_header('Python.h', args: python3_header_check_args, dependencies: python3_dep, required: pyopt, include_directories: postgres_inc) python3_dep = not_found_dep endif endif diff --git a/src/pl/plpython/plpython.h b/src/pl/plpython/plpython.h index 118b310084..445f7bc31a 100644 --- a/src/pl/plpython/plpython.h +++ b/src/pl/plpython/plpython.h @@ -25,12 +25,8 @@ /* * Enable Python Limited API - * - * XXX currently not enabled on MSVC because of build failures */ -#if !defined(_MSC_VER) #define Py_LIMITED_API 0x03020000 -#endif /* * Pull in Python headers via a wrapper header, to control the scope of -- 2.52.0.windows.1