Windows 32-bit build is broken due to calling convention mismatches

[dtmdl]

Describe the bug
Attempting to build with 32-bit python on Windows fails due to calling convention mismatches (__cdecl vs __stdcall):

C:\...\AppData\Local\Temp\pip-build-env-rcjxvoxq\overlay\Lib\site-packages\setuptools\_distutils\dist.py:261: UserWarning: Unknown distribution option: 'test_suite'
warnings.warn(msg)
running bdist_wheel
running build
running build_py
creating build\lib.win32-cpython-311\pyrfc
copying src\pyrfc\_exception.py -> build\lib.win32-cpython-311\pyrfc
copying src\pyrfc\_utils.py -> build\lib.win32-cpython-311\pyrfc
copying src\pyrfc\__init__.py -> build\lib.win32-cpython-311\pyrfc
running build_ext
building 'pyrfc._cyrfc' extension
creating build\temp.win32-cpython-311\Release\src\pyrfc
"C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.41.34120\bin\HostX86\x86\cl.exe" /c /nologo /O2 /W3 /GL /DNDEBUG /MD -DSAPonNT -D_CRT_NON_CONFORMING_SWPRINTFS -D_CRT_SECURE_NO_DEPRECATES -D_CRT_NONSTDC_NO_DEPRECATE -D_AFXDLL -DWIN32 -D_WIN32_WINNT=0x0502 -DWIN64 -D_AMD64_ -DNDEBUG -DSAPwithUNICODE -DUNICODE -D_UNICODE -DSAPwithTHREADS -D_ATL_ALLOW_CHAR_UNSIGNED -D_LARGEFILE_SOURCE -D_CONSOLE -DSAP_PLATFORM_MAKENAME=ntintel -IC:\x\saprfc32\include "-IC:\Program Files (x86)\Python311-32\include" "-IC:\Program Files (x86)\Python311-32\Include" "-IC:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.41.34120\include" "-IC:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Auxiliary\VS\include" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.26100.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.26100.0\\um" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.26100.0\\shared" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.26100.0\\winrt" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.26100.0\\cppwinrt" "-IC:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\include\um" /EHsc /Tpsrc/pyrfc/_cyrfc.cpp /Fobuild\temp.win32-cpython-311\Release\src/pyrfc/_cyrfc.obj -IC:\x\nwrfc750P_14-70002753\nwrfcsdk\include "-IC:\Program Files (x86)\Python311-32\Lib\inspect.py\Include" "-IC:\Program Files (x86)\Python311-32\Lib\inspect.py\Include\PC" /EHs /GL /Gy /J /MD /nologo /O2 /Oy- /we4552 /we4700 /we4789 /W3 /Z7
_cyrfc.cpp
src/pyrfc/_cyrfc.cpp(30499): error C2664: 'RFC_RC RfcInstallAuthorizationCheckHandler(RFC_ON_AUTHORIZATION_CHECK,RFC_ERROR_INFO *)': cannot convert argument 1 from 'RFC_RC (__cdecl *)(RFC_CONNECTION_HANDLE,RFC_SECURITY_ATTRIBUTES *,RFC_ERROR_INFO *)' to 'RFC_ON_AUTHORIZATION_CHECK'
src/pyrfc/_cyrfc.cpp(30499): note: None of the functions with this name in scope match the target type
C:\x\nwrfc750P_14-70002753\nwrfcsdk\include\sapnwrfc.h(2516): note: see declaration of 'RfcInstallAuthorizationCheckHandler'
src/pyrfc/_cyrfc.cpp(30499): note: while trying to match the argument list '(overloaded-function, RFC_ERROR_INFO *)'
src/pyrfc/_cyrfc.cpp(34040): error C2664: 'RFC_RC RfcInstallBgRfcHandlers(const SAP_UC *,RFC_ON_CHECK_UNIT,RFC_ON_COMMIT_UNIT,RFC_ON_ROLLBACK_UNIT,RFC_ON_CONFIRM_UNIT,RFC_ON_GET_UNIT_STATE,RFC_ERROR_INFO *)': cannot convert argument 2 from 'RFC_RC (__cdecl *)(RFC_CONNECTION_HANDLE,const RFC_UNIT_IDENTIFIER *)' to 'RFC_ON_CHECK_UNIT'
src/pyrfc/_cyrfc.cpp(34040): note: None of the functions with this name in scope match the target type
C:\x\nwrfc750P_14-70002753\nwrfcsdk\include\sapnwrfc.h(2448): note: see declaration of 'RfcInstallBgRfcHandlers'
src/pyrfc/_cyrfc.cpp(34040): note: while trying to match the argument list '(SAP_UC *, overloaded-function, overloaded-function, overloaded-function, overloaded-function, overloaded-function, RFC_ERROR_INFO *)'
src/pyrfc/_cyrfc.cpp(34328): error C2664: 'RFC_RC RfcInstallTransactionHandlers(const SAP_UC *,RFC_ON_CHECK_TRANSACTION,RFC_ON_COMMIT_TRANSACTION,RFC_ON_ROLLBACK_TRANSACTION,RFC_ON_CONFIRM_TRANSACTION,RFC_ERROR_INFO *)': cannot convert argument 2 from 'RFC_RC (__cdecl *)(RFC_CONNECTION_HANDLE,const SAP_UC *)' to 'RFC_ON_CHECK_TRANSACTION'
src/pyrfc/_cyrfc.cpp(34328): note: None of the functions with this name in scope match the target type
C:\x\nwrfc750P_14-70002753\nwrfcsdk\include\sapnwrfc.h(2401): note: see declaration of 'RfcInstallTransactionHandlers'
src/pyrfc/_cyrfc.cpp(34328): note: while trying to match the argument list '(SAP_UC *, overloaded-function, overloaded-function, overloaded-function, overloaded-function, RFC_ERROR_INFO *)'
src/pyrfc/_cyrfc.cpp(35141): error C2664: 'RFC_RC RfcInstallGenericServerFunction(RFC_SERVER_FUNCTION,RFC_FUNC_DESC_CALLBACK,RFC_ERROR_INFO *)': cannot convert argument 1 from 'RFC_RC (__cdecl *)(RFC_CONNECTION_HANDLE,RFC_FUNCTION_HANDLE,RFC_ERROR_INFO *)' to 'RFC_SERVER_FUNCTION'
src/pyrfc/_cyrfc.cpp(35141): note: None of the functions with this name in scope match the target type
C:\x\nwrfc750P_14-70002753\nwrfcsdk\include\sapnwrfc.h(2362): note: see declaration of 'RfcInstallGenericServerFunction'
src/pyrfc/_cyrfc.cpp(35141): note: while trying to match the argument list '(overloaded-function, overloaded-function, RFC_ERROR_INFO *)'
src/pyrfc/_cyrfc.cpp(48237): warning C4018: '<': signed/unsigned mismatch
src/pyrfc/_cyrfc.cpp(62459): warning C4551: function call missing argument list
src/pyrfc/_cyrfc.cpp(63060): warning C4551: function call missing argument list
error: command 'C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Tools\\MSVC\\14.41.34120\\bin\\HostX86\\x86\\cl.exe' failed with exit code 2

This patch appears to fix the build (not yet tested it in action), but is a bit of a mess.
I can't work out how to apply __stdcall to a static method, so ripped all of the callbacks out into standalone functions.

Note there are also issues with a hardcoded /MACHINE:amd64 linker flag and suspicious WIN64 and AMD64 compiler flags.

pyrfc-32bit-build-fixes.patch

To Reproduce

• pip install pyrfc==3.3.1

Environment

• Windows 11 22H2
• Python 3.11.9 (32-bit)
• SAP NW RFC 7.50 PL 14 (Windows 32-bit)
• No docker
• Tried PyRFC 3.3.1 and git HEAD