[REACTOS] Delay-load the setuplib DLL and control the path it's loaded from.

The setuplib DLL, used also by the text-mode USETUP, isn't placed in the
standard DLL search paths list. It isn't in the "current" directory nor
in the one where reactos.exe is, nor in the running OS' SystemRoot or
System32 directories.
The DLL is instead placed in the System32 sub-directory of the ReactOS
installation source. Note that this isn't a problem for USETUP, because
it is already started from that directory.

To control its loading, delay-load the DLL and use a delay-load hook,
following the technique explained in:
  https://stackoverflow.com/a/75325443
  https://devblogs.microsoft.com/oldnewthing/20170126-00/?p=95265

The hook is also invoked in case of loading failure, showing a more
user-friendly hard-error popup and killing the installer, instead of
throwing a debugger exception.

base/setup/reactos/CMakeLists.txt

@@ -22,5 +22,6 @@ add_pch(reactos reactos.h SOURCE)
 set_module_type(reactos win32gui UNICODE)
 target_link_libraries(reactos uuid)
 target_link_libraries(reactos zlib_solo) ## We use USETUP's cabinet implementation
-add_importlibs(reactos advapi32 gdi32 user32 comctl32 shlwapi setupapi setuplib msvcrt kernel32 ntdll)
+add_delay_importlibs(reactos setuplib)
+add_importlibs(reactos advapi32 gdi32 user32 comctl32 shlwapi setupapi msvcrt kernel32 ntdll)
 add_cd_file(TARGET reactos DESTINATION reactos NO_CAB FOR bootcd)

base/setup/reactos/reactos.c

@@ -2838,6 +2838,132 @@ HotkeyThread(LPVOID Parameter)
     return 0;
 }
 
+
+static PCWSTR
+GetLocalSetupDllPath(VOID)
+{
+    static WCHAR SetupDllPath[MAX_PATH] = L"";
+    static BOOL Init = FALSE;
+    BOOL Success;
+    DWORD PathSize;
+
+    /* Don't rebuild the path if we did it already */
+    if (Init)
+        return SetupDllPath;
+    Init = TRUE;
+
+    /*
+     * Retrieve the full path of the current running Setup instance.
+     * From this we build the suitable path to the Setup DLL.
+     */
+    PathSize = GetModuleFileNameW(NULL, SetupDllPath, _countof(SetupDllPath));
+    SetupDllPath[_countof(SetupDllPath) - 1] = UNICODE_NULL; // Ensure NULL-termination (see WinXP bug)
+
+    Success = ((PathSize != 0) && (PathSize < _countof(SetupDllPath)) &&
+               (GetLastError() != ERROR_INSUFFICIENT_BUFFER));
+    if (Success)
+    {
+        /* Find the last path separator, remove it as well as the file name */
+        PWCHAR pch = wcsrchr(SetupDllPath, L'\\');
+        if (!pch)
+            pch = SetupDllPath;
+
+        /* The Setup DLL is inside the System32 sub-directory */
+        PathSize = _countof(SetupDllPath) - (pch - SetupDllPath);
+        Success = SUCCEEDED(StringCchCopyW(pch, PathSize, L"\\system32"));
+    }
+    if (!Success)
+    {
+        /* Failure: invalidate the path; the DLL won't be found and delay-loaded */
+        *SetupDllPath = UNICODE_NULL;
+    }
+
+    return SetupDllPath;
+}
+
+#ifndef DECLARE_UNICODE_STRING_SIZE
+#define DECLARE_UNICODE_STRING_SIZE(_var, _size) \
+  WCHAR _var ## _buffer[_size]; \
+  UNICODE_STRING _var = { 0, (_size) * sizeof(WCHAR) , _var ## _buffer }
+#endif
+#include <ndk/exfuncs.h> // For NtRaiseHardError()
+#define DELAYIMP_INSECURE_WRITABLE_HOOKS
+#include <delayimp.h>
+
+/**
+ * @brief
+ * Controls the delay-loading of Setup DLLs from a suitable path.
+ *
+ * @see
+ * https://stackoverflow.com/a/75325443
+ * https://devblogs.microsoft.com/oldnewthing/20170126-00/?p=95265
+ **/
+static FARPROC
+WINAPI setupDelayHook(unsigned dliNotify, PDelayLoadInfo pdli)
+{
+    static CHAR dllPath[MAX_PATH];
+    static PCWSTR setupDllPath = NULL;
+
+    switch (dliNotify)
+    {
+        case dliNotePreLoadLibrary:
+        {
+            // NOTE: Add any other needed setup-specific DLLs there.
+            if (_stricmp(pdli->szDll, "setuplib.dll") == 0)
+            {
+                if (!setupDllPath)
+                    setupDllPath = GetLocalSetupDllPath();
+                if (setupDllPath && *setupDllPath &&
+                    SUCCEEDED(StringCchPrintfA(dllPath, _countof(dllPath), "%S\\%s",
+                                               setupDllPath, pdli->szDll)))
+                {
+                    pdli->szDll = dllPath; /* Set szDll to the new path */
+                }
+            }
+            break; /* Load the DLL using the modified path */
+        }
+
+        case dliFailLoadLib:
+        {
+            /*
+             * Library loading failed.
+             * Raise a hard error instead of the default
+             * exception, and "cleanly" kill the process.
+             */
+            ANSI_STRING DllPathA;
+            DECLARE_UNICODE_STRING_SIZE(DllPathU, MAX_PATH);
+            ULONG_PTR Parameters[] = {(ULONG_PTR)&DllPathU};
+            ULONG Response;
+
+            RtlInitAnsiString(&DllPathA, pdli->szDll);
+            RtlAnsiStringToUnicodeString(&DllPathU, &DllPathA, FALSE);
+            NtRaiseHardError(STATUS_DLL_NOT_FOUND | HARDERROR_OVERRIDE_ERRORMODE,
+                             _countof(Parameters),
+                             0x1,
+                             Parameters,
+                             OptionOk,
+                             &Response);
+            ExitProcess(-1);
+            break;
+        }
+
+        default:
+            break;
+    }
+
+    return NULL;
+}
+
+/**
+ * @brief
+ * Custom delay-loading hooks for loading the Setup DLLs from a suitable path.
+ **/
+// NOTE: MSVC 2015 Update 3 makes this a const variable.
+// #if (_MSC_VER > 1900) || (_MSC_VER == 1900 && _MSC_FULL_VER >= 190024210) ...
+/*ExternC*/ PfnDliHook __pfnDliNotifyHook2  = setupDelayHook;
+/*ExternC*/ PfnDliHook __pfnDliFailureHook2 = setupDelayHook;
+
+
 int WINAPI
 _tWinMain(HINSTANCE hInst,
           HINSTANCE hPrevInstance,