CoreFoundation: clean up module locator logic

Use the address of the function to get a module handle without bumping
the refcount of the module.  This avoids the need to hardcode the
library name and enables the use of CoreFoundation in a statically
linked fashion as well.  We can further reduce the logic by using the
PathCch routine to remove the trailing file specification.  This reduces
the complexity in the module location code and reuses the system
libraries for a small additional cost of an additional iteration of the
string path.

Author: compnerd

CoreFoundation/Base.subproj/CFRuntime.c

@@ -42,6 +42,7 @@ OBJC_EXPORT void *objc_destructInstance(id obj);
 
 #if TARGET_OS_WIN32
 #include <Shellapi.h>
+#include <pathcch.h>
 #endif
 
 enum {
@@ -1321,33 +1322,24 @@ CF_PRIVATE void __CFSocketCleanup(void);
 CF_PRIVATE void __CFStreamCleanup(void);
 
 static CFBundleRef RegisterCoreFoundationBundle(void) {
-#ifdef _DEBUG
-    // might be nice to get this from the project file at some point
-    wchar_t *DLLFileName = (wchar_t *)L"CoreFoundation_debug.dll";
-#else
-    wchar_t *DLLFileName = (wchar_t *)L"CoreFoundation.dll";
-#endif
     wchar_t path[MAX_PATH+1];
     path[0] = path[1] = 0;
     DWORD wResult;
     CFIndex idx;
-    HMODULE ourModule = GetModuleHandleW(DLLFileName);
 
-    CFAssert(ourModule, __kCFLogAssertion, "GetModuleHandle failed");
+    HMODULE ourModule = NULL;
+    GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                       (LPCWSTR)&RegisterCoreFoundationBundle, &ourModule);
+    CFAssert(ourModule, __kCFLogAssertion, "GetModuleHandleExW failed");
 
     wResult = GetModuleFileNameW(ourModule, path, MAX_PATH+1);
     CFAssert1(wResult > 0, __kCFLogAssertion, "GetModuleFileName failed: %d", GetLastError());
     CFAssert1(wResult < MAX_PATH+1, __kCFLogAssertion, "GetModuleFileName result truncated: %s", path);
 
     // strip off last component, the DLL name
-    for (idx = wResult - 1; idx; idx--) {
-        if ('\\' == path[idx]) {
-            path[idx] = '\0';
-            break;
-        }
-    }
+    PathCchRemoveFileSpec(path, wResult);
 
-    CFStringRef fsPath = CFStringCreateWithCharacters(kCFAllocatorSystemDefault, (UniChar*)path, idx);
+    CFStringRef fsPath = CFStringCreateWithCharacters(kCFAllocatorSystemDefault, (UniChar*)path, wcslen(path));
     CFURLRef dllURL = CFURLCreateWithFileSystemPath(kCFAllocatorSystemDefault, fsPath, kCFURLWindowsPathStyle, TRUE);
     CFURLRef bundleURL = CFURLCreateCopyAppendingPathComponent(kCFAllocatorSystemDefault, dllURL, CFSTR("CoreFoundation.resources"), TRUE);
     CFRelease(fsPath);

CoreFoundation/CMakeLists.txt

@@ -478,7 +478,8 @@ if(CMAKE_SYSTEM_NAME STREQUAL Windows)
                           AdvAPI32
                           Secur32
                           User32
-                          mincore)
+                          mincore
+                          pathcch)
   target_link_libraries(CFURLSessionInterface
                         PRIVATE
                           AdvAPI32