Add ABI3T_COMPAT_DLLNAME

Author: encukou

PCbuild/pyproject.props

@@ -49,6 +49,7 @@
     <_PlatformPreprocessorDefinition Condition="$(Platform) == 'x64'">_WIN64;</_PlatformPreprocessorDefinition>
     <_PlatformPreprocessorDefinition Condition="$(Platform) == 'x64' and $(PlatformToolset) != 'ClangCL'">_M_X64;$(_PlatformPreprocessorDefinition)</_PlatformPreprocessorDefinition>
     <_Py3NamePreprocessorDefinition>PY3_DLLNAME=L"$(Py3DllName)$(PyDebugExt)";</_Py3NamePreprocessorDefinition>
+    <_Abi3tCompatDllNamePreprocessorDefinition Condition="$(DisableGil) != 'true'">ABI3T_COMPAT_DLLNAME=L"$(PyAbi3tCompat3DllName)$(PyDebugExt)";</_Abi3tCompatDllNamePreprocessorDefinition>
     <_FreeThreadedPreprocessorDefinition Condition="$(DisableGil) == 'true'">Py_GIL_DISABLED=1;</_FreeThreadedPreprocessorDefinition>
     <_PymallocHugepagesPreprocessorDefinition Condition="$(UsePymallocHugepages) == 'true'">PYMALLOC_USE_HUGEPAGES=1;</_PymallocHugepagesPreprocessorDefinition>
   </PropertyGroup>
@@ -57,6 +58,7 @@
       <AdditionalIncludeDirectories>$(PySourcePath)Include;$(PySourcePath)Include\internal;$(PySourcePath)Include\internal\mimalloc;$(PySourcePath)PC;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;$(_Py3NamePreprocessorDefinition)$(_PlatformPreprocessorDefinition)$(_DebugPreprocessorDefinition)$(_PyStatsPreprocessorDefinition)$(_PydPreprocessorDefinition)$(_FreeThreadedPreprocessorDefinition)$(_PymallocHugepagesPreprocessorDefinition)%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <PreprocessorDefinitions Condition="'$(SupportPGO)' and ($(Configuration) == 'PGInstrument' or $(Configuration) == 'PGUpdate')">_Py_USING_PGO=1;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions Condition="$(DisableGil) != 'true'">$(_Abi3tCompatDllNamePreprocessorDefinition)%(PreprocessorDefinitions)</PreprocessorDefinitions>
 
       <Optimization>MaxSpeed</Optimization>
       <IntrinsicFunctions>true</IntrinsicFunctions>

Python/dynload_win.c

@@ -169,7 +169,16 @@ _Py_CheckPython3(void)
        use that DLL */
     if (PyWin_DLLhModule && GetModuleFileNameW(PyWin_DLLhModule, py3path, MAXPATHLEN)) {
         wchar_t *p = wcsrchr(py3path, L'\\');
+
         if (p) {
+#ifdef ABI3T_COMPAT_DLLNAME
+            wcscpy(p + 1, ABI3T_COMPAT_DLLNAME);
+            hPython3 = LoadLibraryExW(py3path, NULL, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS);
+            if (hPython3 != NULL) {
+                return 1;
+            }
+#endif
+
             wcscpy(p + 1, PY3_DLLNAME);
             hPython3 = LoadLibraryExW(py3path, NULL, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS);
             if (hPython3 != NULL) {
@@ -178,6 +187,13 @@ _Py_CheckPython3(void)
         }
     }
 
+#ifdef ABI3T_COMPAT_DLLNAME
+    hPython3 = LoadLibraryExW(ABI3T_COMPAT_DLLNAME, NULL, LOAD_LIBRARY_SEARCH_APPLICATION_DIR);
+    if (hPython3 != NULL) {
+        return 1;
+    }
+#endif
+
     /* If we can locate python3.dll in our application dir,
        use that DLL */
     hPython3 = LoadLibraryExW(PY3_DLLNAME, NULL, LOAD_LIBRARY_SEARCH_APPLICATION_DIR);