Python Stable ABI: Use Stable ABI, by default on CMake 3.26 (needs Py…

…thon 3.7+)

This setting allows only API that is binary-compatible
with multiple Python versions: from 3.7+ until the next major version
is introduced.

CMakeLists.txt

@@ -8,10 +8,14 @@ project(rpm
 )
 
 # user configurable stuff
+include(CMakeDependentOption)
 option(ENABLE_CUTF8 "Enable C.UTF-8 as default locale" ON)
 option(ENABLE_NLS "Enable native language support" ON)
 option(ENABLE_OPENMP "Enable OpenMP threading support" ON)
 option(ENABLE_PYTHON "Enable Python bindings" ON)
+cmake_dependent_option(
+	ENABLE_PYTHON_SABI "Build Python bindings with the Stable ABI" ON
+	"ENABLE_PYTHON; CMAKE_VERSION VERSION_GREATER_EQUAL 3.26" OFF)
 option(ENABLE_PLUGINS "Enable plugin support" ON)
 option(ENABLE_WERROR "Stop build on warnings" OFF)
 option(ENABLE_SQLITE "Enable sqlite rpmdb support" ON)
@@ -234,7 +238,11 @@ endif()
 list(APPEND db_backends dummy)
 
 if (ENABLE_PYTHON)
-	find_package(Python3 3.2 COMPONENTS Interpreter Development REQUIRED)
+	if (ENABLE_PYTHON_SABI)
+		find_package(Python3 3.7 COMPONENTS Interpreter Development.SABIModule REQUIRED)
+	else ()
+		find_package(Python3 3.2 COMPONENTS Interpreter Development REQUIRED)
+	endif ()
 endif()
 
 if (WITH_CAP)
@@ -344,6 +352,7 @@ if (LIBDW_FOUND)
 	set(HAVE_LIBDW 1)
 endif()
 
+include(CheckSymbolExists)
 check_symbol_exists(major "sys/sysmacros.h" MAJOR_IN_SYSMACROS)
 if (NOT MAJOR_IN_SYSMACROS)
 	check_symbol_exists(major "sys/mkdev.h" MAJOR_IN_MKDEV)

python/CMakeLists.txt

@@ -1,4 +1,4 @@
-Python3_add_library(_rpm
+set (sources
 	rpmmodule.c rpmsystem-py.h
 	header-py.c header-py.h
 	rpmarchive-py.c rpmarchive-py.h
@@ -17,6 +17,12 @@ Python3_add_library(_rpm
 	rpmver-py.c rpmver-py.h
 	spec-py.c spec-py.h
 )
+
+if (ENABLE_PYTHON_SABI)
+	Python3_add_library(_rpm USE_SABI 3.7 ${sources})
+else ()
+	Python3_add_library(_rpm ${sources})
+endif ()
 
 target_link_libraries(_rpm PRIVATE librpmio librpm librpmbuild librpmsign)