Avoid modifying shared DLL objects

[moi15moi]

Currently, comtypes modifies shared DLL objects. Below are examples where such modifications occur:

• _comobject.py, lines 80–83
• _safearray.py, lines 49–103
• automation.py, lines 586–588

As noted in this comment, it is preferable to use ctypes.WinDLL instead of ctypes.windll. This approach avoids modifying shared DLL objects and ensures better isolation.

[junkmd]

+1.

Feel free to open PRs.

[junkmd]

• test_basic.py - A PR has been opened [test\test_basic.py] Use OleDLL instead of windll #764
• test_BSTR.py
• test_outparam.py - A PR has been opened [test\test_outparam.py] Use WinDLL/OleDLL instead of windll/oledll #765
• test_urlhistory.py - A PR has been opened [test\test_urlhistory.py] Use WinDLL instead of windll #766
• tlbparser.py - A PR has been opened [tools\tlbparser.py] Import QueryPathOfRegTypeLib from typeinfo + doc adjustments #763
• test_comobject.py - A PR has been opened [test\test_comobject.py] Use OleDLL instead of oledll #767
• test_stream.py - A PR has been opened [test\test_stream.py] Use OleDLL instead of oledll #768
• server/init.py - A PR has been opened [server\__init__.py] Use OleDLL instead of oledll #769
• init.py - A PR has been opened [__init__.py] Use WinDLL/OleDLL instead of windll/oledll #770

What about test_monikers and test_storage?

[junkmd]

• bstr.py
  Note that I don't really know how we can do it because if I put this code before the definition of the class, BSTR doesn't exist and if I put it after, _SysFreeString in _free: Callable[["BSTR"], Any] isn't defined:

Have you tried this approach?

+_oleaut32 = WinDLL("oleaut32")
+
+_SysFreeString = _oleaut32.SysFreeString
+
+
 class BSTR(_SimpleCData):
     """The windows BSTR data type"""

@@ -18,9 +23,7 @@ class BSTR(_SimpleCData):
         self._needsfree = True
         return self.value

-    def __del__(
-        self, _free: Callable[["BSTR"], Any] = windll.oleaut32.SysFreeString
-    ) -> None:
+    def __del__(self, _free: Callable[["BSTR"], Any] = _SysFreeString) -> None:
         # Free the string if self owns the memory
         # or if instructed by __ctypes_from_outparam__.
         if self._b_base_ is None or self._needsfree:
@@ -35,3 +38,7 @@ class BSTR(_SimpleCData):
         # right thing, it doesn't ensure that SysFreeString is called
         # on destruction.
         return cls(value)
+
+
+_SysFreeString.argtypes = [BSTR]
+_SysFreeString.restype = None

[junkmd]

The work on the remaining files has been completed, and with this, shared DLL objects such as windll.libraryname and oledll.libraryname have been removed from this project.

Below is the result of a Git command to confirm this.

PS ...\comtypes> git grep -n -C 2 "windll" -- @(git ls-files)
comtypes/_comobject.py-450-
comtypes/_comobject.py-451-    def IDispatch_GetIDsOfNames(self, this, riid, rgszNames, cNames, lcid, rgDispId):
comtypes/_comobject.py:452:        # This call uses windll instead of oledll so that a failed
comtypes/_comobject.py-453-        # call to DispGetIDsOfNames will return a HRESULT instead of
comtypes/_comobject.py-454-        # raising an error.
--
comtypes/_comobject.py-483-                # values, without going through GetIDsOfNames first.
comtypes/_comobject.py-484-                return hresult.DISP_E_MEMBERNOTFOUND
comtypes/_comobject.py:485:            # This call uses windll instead of oledll so that a failed
comtypes/_comobject.py-486-            # call to DispInvoke will return a HRESULT instead of raising
comtypes/_comobject.py-487-            # an error.
--
comtypes/tools/tlbparser.py-1-import os
comtypes/tools/tlbparser.py-2-import sys
comtypes/tools/tlbparser.py:3:from ctypes import alignment, c_void_p, sizeof, windll
comtypes/tools/tlbparser.py-4-from typing import Any, Dict, List, Optional, Tuple
comtypes/tools/tlbparser.py-5-
--
comtypes/tools/tlbparser.py-750-        # workaround Windows 7 bug in QueryPathOfRegTypeLib returning relative path
comtypes/tools/tlbparser.py-751-        try:
comtypes/tools/tlbparser.py:752:            dll = windll.LoadLibrary(full_filename)
comtypes/tools/tlbparser.py-753-            full_filename = _get_module_filename(dll._handle)
comtypes/tools/tlbparser.py-754-            del dll

PS ...\comtypes> git grep -n -C 2 "oledll" -- @(git ls-files)
comtypes/_comobject.py-450-
comtypes/_comobject.py-451-    def IDispatch_GetIDsOfNames(self, this, riid, rgszNames, cNames, lcid, rgDispId):
comtypes/_comobject.py:452:        # This call uses windll instead of oledll so that a failed
comtypes/_comobject.py-453-        # call to DispGetIDsOfNames will return a HRESULT instead of
comtypes/_comobject.py-454-        # raising an error.
--
comtypes/_comobject.py-483-                # values, without going through GetIDsOfNames first.
comtypes/_comobject.py-484-                return hresult.DISP_E_MEMBERNOTFOUND
comtypes/_comobject.py:485:            # This call uses windll instead of oledll so that a failed
comtypes/_comobject.py-486-            # call to DispInvoke will return a HRESULT instead of raising
comtypes/_comobject.py-487-            # an error.

Thank you for handling the large code changes and for splitting the modifications to make reviewing easier.

[moi15moi]

Perfect, is there any task left before we can close this issue?

Do you have in mind to switch all the OleDLL to WinDLL?

[junkmd]

There shouldn’t be anything left for us to do on this issue.

Feel free to close it.