Replace transmuted references with explicit pointer type casts

This commit replaces almost all usages of `std::mem::transmute` on references in the codebase with explicit pointer type casts.
This is done to prevent undefined behavior caused by transmuting integer types to references, and subsequently dereferencing them.

native-windows-gui/src/controls/date_picker.rs

@@ -162,7 +162,7 @@ impl DatePicker {
 
         let handle = check_hwnd(&self.handle, NOT_BOUND, BAD_HANDLE);
 
-        let info = unsafe{ get_dtp_info(handle) };
+        let info = get_dtp_info(handle);
 
         match info.stateCheck {
             STATE_SYSTEM_CHECKED => true,
@@ -185,13 +185,15 @@ impl DatePicker {
     pub fn value(&self) -> Option<DatePickerValue> {
         use winapi::um::commctrl::{GDT_VALID, DTM_GETSYSTEMTIME};
         use winapi::um::minwinbase::SYSTEMTIME;
+        use winapi::shared::minwindef::LPARAM;
         use std::mem;
 
         let handle = check_hwnd(&self.handle, NOT_BOUND, BAD_HANDLE);
 
         let mut syst: SYSTEMTIME = unsafe{ mem::zeroed() };
+        let syst_ptr = &mut syst as *mut _;
 
-        let r = unsafe{ wh::send_message(handle, DTM_GETSYSTEMTIME, 0, mem::transmute(&mut syst)) };
+        let r = wh::send_message(handle, DTM_GETSYSTEMTIME, 0, syst_ptr as LPARAM);
         match r {
             GDT_VALID => Some(DatePickerValue {
                 year: syst.wYear,
@@ -488,14 +490,15 @@ impl<'a> DatePickerBuilder<'a> {
 use winapi::um::commctrl::DATETIMEPICKERINFO;
 use winapi::shared::windef::HWND;
 
-unsafe fn get_dtp_info(handle: HWND) -> DATETIMEPICKERINFO {
+fn get_dtp_info(handle: HWND) -> DATETIMEPICKERINFO {
     use winapi::um::commctrl::DTM_GETDATETIMEPICKERINFO;
-    use winapi::shared::minwindef::DWORD;
+    use winapi::shared::minwindef::{DWORD, LPARAM};
     use std::mem;
 
-    let mut dtp_info: DATETIMEPICKERINFO = mem::zeroed();
+    let mut dtp_info: DATETIMEPICKERINFO = unsafe { mem::zeroed() };
     dtp_info.cbSize = mem::size_of::<DATETIMEPICKERINFO>() as DWORD;
-    wh::send_message(handle, DTM_GETDATETIMEPICKERINFO, 0, mem::transmute(&mut dtp_info));
+    let dtp_info_ptr = &mut dtp_info as *mut _;
+    wh::send_message(handle, DTM_GETDATETIMEPICKERINFO, 0, dtp_info_ptr as LPARAM);
 
     dtp_info
 }

native-windows-gui/src/controls/extern_canvas.rs

@@ -130,14 +130,13 @@ impl ExternCanvas {
     /// - icon: The new icon. If None, the icon is removed
     pub fn set_icon(&self, icon: Option<&Icon>) {
         use winapi::um::winuser::WM_SETICON;
-        use std::{mem, ptr};
+        use winapi::shared::minwindef::LPARAM;
+        use std::ptr;
 
         let handle = check_hwnd(&self.handle, NOT_BOUND, BAD_HANDLE);
 
         let image_handle = icon.map(|i| i.handle).unwrap_or(ptr::null_mut());
-        unsafe {
-            wh::send_message(handle, WM_SETICON, 0, mem::transmute(image_handle));
-        }
+        wh::send_message(handle, WM_SETICON, 0, image_handle as LPARAM);
     }
 
     /// Return true if the control currently has the keyboard focus

native-windows-gui/src/controls/list_box.rs

@@ -106,9 +106,7 @@ impl<D: Display+Default> ListBox<D> {
         let display = format!("{}", item);
         let display_os = to_utf16(&display);
 
-        unsafe {
-            wh::send_message(handle, LB_ADDSTRING, 0, mem::transmute(display_os.as_ptr()));
-        }
+        wh::send_message(handle, LB_ADDSTRING, 0, display_os.as_ptr() as LPARAM);
 
         self.collection.borrow_mut().push(item);
     }
@@ -131,9 +129,7 @@ impl<D: Display+Default> ListBox<D> {
             col.insert(index, item);
         }
 
-        unsafe {
-            wh::send_message(handle, LB_INSERTSTRING, index, mem::transmute(display_os.as_ptr()));
-        }
+        wh::send_message(handle, LB_INSERTSTRING, index, display_os.as_ptr() as LPARAM);
     }
 
 
@@ -215,10 +211,8 @@ impl<D: Display+Default> ListBox<D> {
             let index = index as usize;
             let length = (wh::send_message(handle, LB_GETTEXTLEN, index, 0) as usize) + 1;  // +1 for the terminating null character
             let mut buffer: Vec<WCHAR> = Vec::with_capacity(length);
-            unsafe { 
-                buffer.set_len(length); 
-                wh::send_message(handle, LB_GETTEXT, index, mem::transmute(buffer.as_ptr()));
-            }
+            unsafe { buffer.set_len(length); }
+            wh::send_message(handle, LB_GETTEXT, index, buffer.as_ptr() as LPARAM);
 
             Some(from_utf16(&buffer))
         }
@@ -292,13 +286,11 @@ impl<D: Display+Default> ListBox<D> {
         let handle = check_hwnd(&self.handle, NOT_BOUND, BAD_HANDLE);
         let os_string = to_utf16(value);
 
-        unsafe {
-            let index = wh::send_message(handle, LB_SELECTSTRING, 0, mem::transmute(os_string.as_ptr()));
-            if index == LB_ERR {
-                None
-            } else {
-                Some(index as usize)
-            }
+        let index = wh::send_message(handle, LB_SELECTSTRING, 0, os_string.as_ptr() as LPARAM);
+        if index == LB_ERR {
+            None
+        } else {
+            Some(index as usize)
         }
     }
 
@@ -327,9 +319,7 @@ impl<D: Display+Default> ListBox<D> {
             let display = format!("{}", item);
             let display_os = to_utf16(&display);
 
-            unsafe {
-                wh::send_message(handle, LB_ADDSTRING, 0, mem::transmute(display_os.as_ptr()));
-            }
+            wh::send_message(handle, LB_ADDSTRING, 0, display_os.as_ptr() as LPARAM);
         }
     }
 
@@ -345,9 +335,7 @@ impl<D: Display+Default> ListBox<D> {
             let display = format!("{}", item);
             let display_os = to_utf16(&display);
 
-            unsafe {
-                wh::send_message(handle, LB_ADDSTRING, 0, mem::transmute(display_os.as_ptr()));
-            }
+            wh::send_message(handle, LB_ADDSTRING, 0, display_os.as_ptr() as LPARAM);
         }
 
         let mut col_ref = self.collection.borrow_mut();

native-windows-gui/src/controls/tabs.rs

@@ -5,6 +5,7 @@ use winapi::um::winuser::{EnumChildWindows, WS_VISIBLE, WS_DISABLED, WS_EX_CONTR
 use crate::win32::{base_helper::{to_utf16, check_hwnd}, window_helper as wh};
 use crate::{NwgError, Font, RawEventHandler, unbind_raw_event_handler};
 use super::{ControlBase, ControlHandle};
+use std::intrinsics::saturating_add;
 use std::{mem, cell::RefCell};
 
 #[cfg(feature="image-list")]
@@ -265,7 +266,7 @@ impl TabsContainer {
         let handler0 = bind_raw_event_handler_inner(&parent_handle, handle as usize, move |_hwnd, msg, _w, l| { unsafe {
             match msg {
                 WM_NOTIFY => {
-                    let nmhdr: &NMHDR = mem::transmute(l);
+                    let nmhdr = &*(l as *const NMHDR);
                     if nmhdr.code == TCN_SELCHANGE {
                         let index = SendMessageW(handle, TCM_GETCURSEL, 0, 0) as i32;
                         let data: (HWND, i32) = (handle, index);
@@ -318,7 +319,7 @@ impl TabsContainer {
                     data.tab_offset_y = tab_height;
 
                     let data_ptr = &data as *const ResizeDirectChildrenParams;
-                    EnumChildWindows(hwnd, Some(resize_direct_children), mem::transmute(data_ptr));
+                    EnumChildWindows(hwnd, Some(resize_direct_children), data_ptr as LPARAM);
                 },
                 _ => {}
             }
@@ -612,7 +613,7 @@ impl Tab {
         let count_ptr = &mut count as *mut usize;
 
         unsafe {
-            EnumChildWindows(tab_view_handle, Some(count_children), mem::transmute(count_ptr));
+            EnumChildWindows(tab_view_handle, Some(count_children), count_ptr as LPARAM);
         }
 
         count
@@ -757,7 +758,7 @@ unsafe extern "system" fn count_children(handle: HWND, params: LPARAM) -> BOOL {
 
     if &wh::get_window_class_name(handle) == "NWG_TAB" {
         let tab_index = (wh::get_window_long(handle, GWL_USERDATA)) as WPARAM;
-        let count: &mut usize = ::std::mem::transmute(params);
+        let count = params as *mut usize;
         *count = usize::max(tab_index+1, *count);
     }
 
@@ -768,7 +769,7 @@ unsafe extern "system" fn count_children(handle: HWND, params: LPARAM) -> BOOL {
 unsafe extern "system" fn toggle_children_tabs(handle: HWND, params: LPARAM) -> BOOL {
     use winapi::um::winuser::GWL_USERDATA;
 
-    let &(parent, index): &(HWND, i32) = mem::transmute(params);
+    let (parent, index) = *(params as *const (HWND, i32));
     if wh::get_window_parent(handle) == parent {
         let tab_index = wh::get_window_long(handle, GWL_USERDATA) as i32;
         let visible = tab_index == index + 1;

native-windows-gui/src/controls/window.rs

@@ -158,14 +158,13 @@ impl Window {
     /// - icon: The new icon. If None, the icon is removed
     pub fn set_icon(&self, icon: Option<&Icon>) {
         use winapi::um::winuser::WM_SETICON;
-        use std::{mem, ptr};
+        use winapi::shared::minwindef::LPARAM;
+        use std::ptr;
 
         let handle = check_hwnd(&self.handle, NOT_BOUND, BAD_HANDLE);
 
         let image_handle = icon.map(|i| i.handle).unwrap_or(ptr::null_mut());
-        unsafe {
-            wh::send_message(handle, WM_SETICON, 0, mem::transmute(image_handle));
-        }
+        wh::send_message(handle, WM_SETICON, 0, image_handle as LPARAM);
     }
 
     /// Return true if the control currently has the keyboard focus

native-windows-gui/src/resources/file_dialog.rs

@@ -1,4 +1,4 @@
-use winapi::um::shobjidl::IFileDialog;
+use winapi::um::shobjidl::{IFileDialog, IFileOpenDialog};
 use crate::win32::resources_helper as rh;
 
 use crate::win32::base_helper::to_utf16;
@@ -115,7 +115,7 @@ impl FileDialog {
         }
 
         unsafe {
-            rh::filedialog_get_items(mem::transmute(&mut *self.handle))
+            rh::filedialog_get_items(&mut *(self.handle as *mut IFileOpenDialog))
         }
     }
 

native-windows-gui/src/win32/menu.rs

@@ -1,6 +1,7 @@
 /*!
 Native Windows GUI menu base.
 */
+use winapi::shared::basetsd::UINT_PTR;
 use winapi::shared::windef::{HMENU, HWND};
 use winapi::shared::minwindef::UINT;
 use super::base_helper::{CUSTOM_ID_BEGIN, to_utf16};
@@ -70,7 +71,7 @@ pub unsafe fn build_hmenu_control(text: Option<String>, item: bool, separator: b
                 return Err(NwgError::menu_create("Menu without parent"));
             }
             use_menu_command(menu);
-            AppendMenuW(menubar, flags, mem::transmute(menu), text.as_ptr());
+            AppendMenuW(menubar, flags, menu as UINT_PTR, text.as_ptr());
         }
 
         // Draw the menu bar to make sure the changes are visible
@@ -89,7 +90,7 @@ pub unsafe fn build_hmenu_control(text: Option<String>, item: bool, separator: b
                 return Err(NwgError::menu_create("Menu without parent"));
             }
             use_menu_command(menu);
-            AppendMenuW(parent, flags, mem::transmute(menu), text.as_ptr());
+            AppendMenuW(parent, flags, menu as UINT_PTR, text.as_ptr());
         }
     }
 

native-windows-gui/src/win32/resources_helper.rs

@@ -349,14 +349,15 @@ pub unsafe fn create_file_dialog<'a, 'b>(
     use winapi::um::shobjidl::{FOS_PICKFOLDERS, FOS_ALLOWMULTISELECT, FOS_FORCEFILESYSTEM};
     use winapi::um::combaseapi::CoCreateInstance;
     use winapi::shared::{wtypesbase::CLSCTX_INPROC_SERVER, winerror::S_OK};
+    use winapi::shared::minwindef::LPVOID;
 
     let (clsid, uuid) = match action {
         FileDialogAction::Save => (CLSID_FileSaveDialog, IFileDialog::uuidof()),
         _ => (CLSID_FileOpenDialog, IFileOpenDialog::uuidof())
     };
 
     let mut handle: *mut IFileDialog = ptr::null_mut();
-    let r = CoCreateInstance(&clsid, ptr::null_mut(), CLSCTX_INPROC_SERVER, &uuid, mem::transmute(&mut handle) );
+    let r = CoCreateInstance(&clsid, ptr::null_mut(), CLSCTX_INPROC_SERVER, &uuid, &mut handle as *mut _ as *mut LPVOID);
     if r != S_OK {
         return Err(NwgError::file_dialog("Filedialog creation failed"));
     }
@@ -418,7 +419,7 @@ pub unsafe fn file_dialog_set_default_folder<'a>(dialog: &mut IFileDialog, folde
     let mut shellitem: *mut IShellItem = ptr::null_mut();
     let path = to_utf16(&folder_name);
 
-    if SHCreateItemFromParsingName(path.as_ptr(), ptr::null_mut(), &IShellItem::uuidof(), mem::transmute(&mut shellitem) ) != S_OK {
+    if SHCreateItemFromParsingName(path.as_ptr(), ptr::null_mut(), &IShellItem::uuidof(), &mut shellitem as *mut _ as *mut *mut c_void) != S_OK {
         return Err(NwgError::file_dialog("Failed to set default folder"));
     }
 
@@ -504,7 +505,7 @@ pub unsafe fn filedialog_get_items(dialog: &mut IFileOpenDialog) -> Result<Vec<O
     let mut _item: *mut IShellItem = ptr::null_mut();
     let mut _items: *mut IShellItemArray = ptr::null_mut();
 
-    if dialog.GetResults( mem::transmute(&mut _items) ) != S_OK {
+    if dialog.GetResults(&mut _items as *mut _) != S_OK {
         return Err(NwgError::file_dialog("Failed to get dialog items"));
     }
 
@@ -530,6 +531,7 @@ pub unsafe fn filedialog_get_items(dialog: &mut IFileOpenDialog) -> Result<Vec<O
 unsafe fn get_ishellitem_path(item: &mut IShellItem) -> Result<OsString, NwgError> {
     use winapi::um::shobjidl_core::SIGDN_FILESYSPATH;
     use winapi::shared::{ntdef::PWSTR, winerror::S_OK};
+    use winapi::shared::minwindef::LPVOID;
     use winapi::um::combaseapi::CoTaskMemFree;
     use super::base_helper::os_string_from_wide_ptr;
 
@@ -540,7 +542,7 @@ unsafe fn get_ishellitem_path(item: &mut IShellItem) -> Result<OsString, NwgErro
 
     let text = os_string_from_wide_ptr(item_path, None);
 
-    CoTaskMemFree(mem::transmute(item_path));
+    CoTaskMemFree(item_path as LPVOID);
 
     Ok(text)
 }

native-windows-gui/src/win32/window.rs

@@ -597,17 +597,17 @@ unsafe extern "system" fn process_events(hwnd: HWND, msg: UINT, w: WPARAM, l: LP
         },
         WM_NOTIFY => {
             let code = {
-                let notif_ptr: *mut NMHDR = mem::transmute(l);
+                let notif_ptr = l as *mut NMHDR;
                 (&*notif_ptr).code
             };
 
             match code {
-                TTN_GETDISPINFOW => handle_tooltip_callback(mem::transmute::<_, *mut NMTTDISPINFOW>(l), callback),
-                _ => handle_default_notify_callback(mem::transmute::<_, *const NMHDR>(l), callback)
+                TTN_GETDISPINFOW => handle_tooltip_callback(l as *mut NMTTDISPINFOW, callback),
+                _ => handle_default_notify_callback(l as *const NMHDR, callback)
             }
         },
         WM_MENUCOMMAND => {
-            let parent_handle: HMENU = mem::transmute(l);
+            let parent_handle = l as HMENU;
             let item_id = GetMenuItemID(parent_handle, w as i32);
             let handle = ControlHandle::MenuItem(parent_handle, item_id);
             callback(Event::OnMenuItemSelected, NO_DATA, handle);
@@ -1074,7 +1074,12 @@ unsafe fn GetWindowSubclass(hwnd: HWND, proc: SUBCLASSPROC, uid: UINT_PTR, data:
         SUBCLASS_COLLECTION = Some(Mutex::new(HashMap::new()));
     }
 
-    let id = (hwnd as usize, mem::transmute(proc), uid);
+    let proc_id = match proc {
+        Some(p) => p as usize,
+        None => 0
+    };
+
+    let id = (hwnd as usize, proc_id, uid);
     match SUBCLASS_COLLECTION.as_ref() {
         Some(collection_mutex) => {
             let collection = collection_mutex.lock().unwrap();
@@ -1096,7 +1101,12 @@ unsafe fn SetWindowSubclass(hwnd: HWND, proc: SUBCLASSPROC, uid: UINT_PTR, data:
         SUBCLASS_COLLECTION = Some(Mutex::new(HashMap::new()));
     }
 
-    let id = (hwnd as usize, mem::transmute(proc), uid);
+    let proc_id = match proc {
+        Some(p) => p as usize,
+        None => 0
+    };
+
+    let id = (hwnd as usize, proc_id, uid);
     match SUBCLASS_COLLECTION.as_ref() {
         Some(collection_mutex) => {
             let mut collection = collection_mutex.lock().unwrap();
@@ -1119,7 +1129,12 @@ unsafe fn RemoveWindowSubclass(hwnd: HWND, proc: SUBCLASSPROC, uid: UINT_PTR) ->
         SUBCLASS_COLLECTION = Some(Mutex::new(HashMap::new()));
     }
 
-    let id = (hwnd as usize, mem::transmute(proc), uid);
+    let proc_id = match proc {
+        Some(p) => p as usize,
+        None => 0
+    };
+
+    let id = (hwnd as usize, proc_id, uid);
     match SUBCLASS_COLLECTION.as_ref() {
         Some(collection_mutex) => {
             let mut collection = collection_mutex.lock().unwrap();

native-windows-gui/src/win32/window_helper.rs

@@ -169,10 +169,7 @@ pub fn get_window_parent(hwnd: HWND) -> HWND {
 
 pub fn get_window_font(handle: HWND) -> HFONT {
     use winapi::um::winuser::{ WM_GETFONT };
-    unsafe { 
-        let h = send_message(handle, WM_GETFONT, 0, 0);
-        mem::transmute(h)
-    }
+    send_message(handle, WM_GETFONT, 0, 0) as HFONT
 }
 
 pub fn maximize_window(handle: HWND) {
@@ -203,7 +200,7 @@ pub unsafe fn set_window_font(handle: HWND, font_handle: Option<HFONT>, redraw:
 
     let font_handle = font_handle.unwrap_or(ptr::null_mut());
 
-    SendMessageW(handle, WM_SETFONT, mem::transmute(font_handle), redraw as LPARAM);
+    SendMessageW(handle, WM_SETFONT, font_handle as WPARAM, redraw as LPARAM);
 }