fix clippy warnings for macos

- Warnings related to unsafe code has not been touched.
- The number of warnings has been reduced from 381 to 7 errors (denied lints).

Fixes:
- replaced unmaintained objc crate with fork SSheldon/rust-objc#125.
  - Ideally it would be replaced with https://github.com/madsmtm/objc2 but that'd be too much work.
- simplified zero pointers and redundant casts and clones.
- fixed slow zero-filling vector initialization.
- simplified unneeded explicit returns.
- simplified unnecessary lifetimes.
- ...among others.

Cargo.toml

@@ -43,7 +43,7 @@ libc = "0.2"
 ndk-sys = "0.2"
 
 [target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
-objc = "0.2"
+objc = { package = "objc-rs", version = "0.2" }
 
 [dev-dependencies]
 glam = { version = "0.24", features = ["scalar-math"] }

src/graphics/metal.rs

@@ -281,6 +281,12 @@ pub struct MetalContext {
     current_ub_offset: u64,
 }
 
+impl Default for MetalContext {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl MetalContext {
     pub fn new() -> MetalContext {
         unsafe {
@@ -589,6 +595,7 @@ impl RenderingBackend for MetalContext {
             BufferSource::Slice(data) => data.size,
             BufferSource::Empty { size, .. } => *size,
         };
+        #[allow(clippy::needless_range_loop)]
         for i in 0..BUFFERS_IN_ROTATION {
             let buffer: ObjcId = if let BufferSource::Slice(data) = &data {
                 debug_assert!(data.is_slice);
@@ -619,7 +626,7 @@ impl RenderingBackend for MetalContext {
         }
         let buffer = Buffer {
             raw,
-            size: size as usize,
+            size,
             value: 0,
             next_value: 0,
         };
@@ -804,8 +811,8 @@ impl RenderingBackend for MetalContext {
                         let raw_texture = self.textures.get(texture).texture;
                         let region = MTLRegion {
                             origin: MTLOrigin {
-                                x: 0 as u64,
-                                y: 0 as u64,
+                                x: 0_u64,
+                                y: 0_u64,
                                 z: 0,
                             },
                             size: MTLSize {
@@ -1155,11 +1162,7 @@ impl RenderingBackend for MetalContext {
                 None => {
                     let (screen_width, screen_height) = crate::window::screen_size();
                     (
-                        {
-                            let a = msg_send_![self.view, currentRenderPassDescriptor];
-                            //msg_send_![a, retain];
-                            a
-                        },
+                        msg_send_![self.view, currentRenderPassDescriptor],
                         screen_width as f64,
                         screen_height as f64,
                     )

src/lib.rs

@@ -1,6 +1,7 @@
 #![doc = include_str!("../README.md")]
 #![allow(
     clippy::collapsible_if,
+    clippy::collapsible_else_if,
     clippy::unused_unit,
     clippy::identity_op,
     clippy::missing_safety_doc

src/native/apple/apple_util.rs

@@ -67,35 +67,30 @@ pub unsafe fn cfstring_ref_to_string(cfstring: CFStringRef) -> String {
         kCFStringEncodingUTF8,
         0,
         false,
-        0 as *mut u8,
+        std::ptr::null_mut::<u8>(),
         0,
         &mut num_bytes,
     );
     if converted == 0 || num_bytes == 0 {
         return String::new();
     }
-    let mut buffer = Vec::new();
-    buffer.resize(num_bytes as usize, 0u8);
+    let mut buffer = vec![0u8; num_bytes as usize];
     CFStringGetBytes(
         cfstring,
         range,
         kCFStringEncodingUTF8,
         0,
         false,
-        buffer.as_mut_ptr() as *mut u8,
+        buffer.as_mut_ptr(),
         num_bytes,
-        0 as *mut u64,
+        std::ptr::null_mut::<u64>(),
     );
-    if let Ok(val) = String::from_utf8(buffer) {
-        val
-    } else {
-        String::new()
-    }
+    String::from_utf8(buffer).unwrap_or_default()
 }
 
 pub fn load_webkit_cursor(cursor_name_str: &str) -> ObjcId {
     unsafe {
-        static CURSOR_ROOT: &'static str = "/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/HIServices.framework/Versions/A/Resources/cursors";
+        static CURSOR_ROOT: &str = "/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/HIServices.framework/Versions/A/Resources/cursors";
         let cursor_root = str_to_nsstring(CURSOR_ROOT);
         let cursor_name = str_to_nsstring(cursor_name_str);
         let cursor_pdf = str_to_nsstring("cursor.pdf");
@@ -137,7 +132,7 @@ pub fn get_event_char(event: ObjcId) -> Option<char> {
         }
         let chars = nsstring_to_string(characters);
 
-        if chars.len() == 0 {
+        if chars.is_empty() {
             return None;
         }
         Some(chars.chars().next().unwrap())
@@ -402,7 +397,7 @@ pub fn keycode_to_menu_key(keycode: KeyCode, shift: bool) -> &'static str {
     }
 }
 
-pub unsafe fn superclass<'a>(this: &'a Object) -> &'a Class {
+pub unsafe fn superclass(this: &Object) -> &Class {
     let superclass: ObjcId = msg_send![this, superclass];
     &*(superclass as *const _)
 }

src/native/apple/frameworks.rs

@@ -853,7 +853,7 @@ pub enum NSDragOperation {
 
 unsafe impl Encode for NSDragOperation {
     fn encode() -> Encoding {
-        let encoding = format!("Q");
+        let encoding = "Q".to_string();
         unsafe { Encoding::from_str(&encoding) }
     }
 }

src/native/macos.rs

@@ -256,8 +256,7 @@ pub fn define_app_delegate() -> *const Class {
             yes1 as extern "C" fn(&Object, Sel, ObjcId) -> BOOL,
         );
     }
-
-    return decl.register();
+    decl.register()
 }
 
 pub fn define_cocoa_window_delegate() -> *const Class {
@@ -284,9 +283,9 @@ pub fn define_cocoa_window_delegate() -> *const Class {
             }
         }
         if native_display().lock().unwrap().quit_ordered {
-            return YES;
+            YES
         } else {
-            return NO;
+            NO
         }
     }
 
@@ -328,11 +327,7 @@ pub fn define_cocoa_window_delegate() -> *const Class {
             let responds: bool = msg_send![payload.window, respondsToSelector:sel!(occlusionState)];
             if responds {
                 let state: u64 = msg_send![payload.window, occlusionState];
-                if state & NSWindowOcclusionStateVisible != 0 {
-                    payload.occluded = false;
-                } else {
-                    payload.occluded = true;
-                }
+                payload.occluded = state & NSWindowOcclusionStateVisible == 0;
             }
         }
     }
@@ -375,7 +370,7 @@ pub fn define_cocoa_window_delegate() -> *const Class {
     // Store internal state as user data
     decl.add_ivar::<*mut c_void>("display_ptr");
 
-    return decl.register();
+    decl.register()
 }
 
 unsafe fn get_proc_address(name: *const u8) -> Option<unsafe extern "C" fn()> {
@@ -485,7 +480,7 @@ unsafe fn view_base_decl(decl: &mut ClassDecl) {
                 let cursor_id = *payload
                     .cursors
                     .entry(current_cursor)
-                    .or_insert_with(|| load_mouse_cursor(current_cursor.clone()));
+                    .or_insert_with(|| load_mouse_cursor(current_cursor));
                 assert!(!cursor_id.is_null());
                 cursor_id
             };
@@ -737,10 +732,9 @@ pub fn define_opengl_view_class() -> *const Class {
 
         view_base_decl(&mut decl);
     }
-
     decl.add_ivar::<*mut c_void>("display_ptr");
 
-    return decl.register();
+    decl.register()
 }
 
 pub fn define_metal_view_class() -> *const Class {
@@ -769,7 +763,7 @@ pub fn define_metal_view_class() -> *const Class {
         view_base_decl(&mut decl);
     }
 
-    return decl.register();
+    decl.register()
 }
 
 fn get_window_payload(this: &Object) -> &mut MacosDisplay {
@@ -797,6 +791,7 @@ unsafe fn create_metal_view(_: &mut MacosDisplay, sample_count: i32, _: bool) ->
     view
 }
 
+#[allow(clippy::vec_init_then_push)]
 unsafe fn create_opengl_view(
     display: &mut MacosDisplay,
     sample_count: i32,
@@ -865,12 +860,12 @@ impl crate::native::Clipboard for MacosClipboard {
 }
 
 unsafe extern "C" fn release_data(info: *mut c_void, _: *const c_void, _: usize) {
-    drop(Box::from_raw(info));
+    drop(Box::from_raw(info as *mut &[u8]));
 }
 
 unsafe fn set_icon(ns_app: ObjcId, icon: &Icon) {
-    let width = 64 as usize;
-    let height = 64 as usize;
+    let width = 64_usize;
+    let height = 64_usize;
     let colors = &icon.big[..];
     let rgb = CGColorSpaceCreateDeviceRGB();
     let bits_per_component: usize = 8; // number of bits in UInt8
@@ -1069,7 +1064,7 @@ where
     let window: ObjcId = msg_send![
         window,
         initWithContentRect: window_frame
-        styleMask: window_masks as u64
+        styleMask: window_masks
         backing: NSBackingStoreType::NSBackingStoreBuffered as u64
         defer: NO
     ];