Improve no_std support in dispatch2 and objc2-foundation

Author: madsmtm

crates/dispatch2/src/ffi.rs

@@ -3,7 +3,7 @@
 #![allow(missing_docs, non_camel_case_types)]
 
 use core::ffi::{c_long, c_uint, c_ulong, c_void};
-use std::ptr::addr_of;
+use core::ptr::addr_of;
 
 #[cfg(feature = "objc2")]
 use objc2::encode::{Encode, Encoding, RefEncode};

crates/dispatch2/src/group.rs

@@ -1,8 +1,8 @@
 //! Dispatch group definition.
 
-use std::time::Duration;
-
+use alloc::boxed::Box;
 use core::ffi::c_void;
+use core::time::Duration;
 
 use super::object::DispatchObject;
 use super::queue::Queue;

crates/dispatch2/src/lib.rs

@@ -17,13 +17,22 @@
 //! queue.exec_async(|| println!("Hello"));
 //! queue.exec_sync(|| println!("World"));
 //! ```
+#![no_std]
 #![allow(unreachable_patterns)]
 #![warn(missing_docs)]
 #![warn(clippy::undocumented_unsafe_blocks)]
 #![warn(clippy::missing_safety_doc)]
 // Update in Cargo.toml as well.
 #![doc(html_root_url = "https://docs.rs/dispatch2/0.1.0")]
 
+#[cfg(not(feature = "alloc"))]
+compile_error!("The `alloc` feature currently must be enabled.");
+
+extern crate alloc;
+
+#[cfg(feature = "std")]
+extern crate std;
+
 use self::ffi::dispatch_qos_class_t;
 
 pub mod ffi;

crates/dispatch2/src/main_thread_bound.rs

@@ -120,7 +120,7 @@ impl<T> MainThreadBound<T> {
     /// Create a shared static that is only available from the main thread.
     ///
     /// ```
-    /// use std::cell::Cell;
+    /// use core::cell::Cell;
     /// use dispatch2::MainThreadBound;
     /// use objc2::MainThreadMarker;
     ///

crates/dispatch2/src/object.rs

@@ -1,5 +1,7 @@
 //! Dispatch object definition.
 
+use alloc::boxed::Box;
+
 use super::{ffi::*, queue::Queue, utils::function_wrapper, QualityOfServiceClass};
 
 /// Error returned by [DispatchObject::set_target_queue].

crates/dispatch2/src/once.rs

@@ -1,10 +1,9 @@
+use core::cell::UnsafeCell;
 use core::ffi::c_void;
 use core::fmt;
+use core::panic::{RefUnwindSafe, UnwindSafe};
 use core::ptr::NonNull;
-use std::cell::UnsafeCell;
-use std::panic::{RefUnwindSafe, UnwindSafe};
-use std::sync::atomic::AtomicIsize;
-use std::sync::atomic::Ordering;
+use core::sync::atomic::{AtomicIsize, Ordering};
 
 use crate::ffi;
 
@@ -166,13 +165,13 @@ impl Once {
                 invoke_dispatch_once(predicate, work);
             }
 
-            // NOTE: Unlike in C, we cannot use `std::hint::assert_unchecked`,
+            // NOTE: Unlike in C, we cannot use `core::hint::assert_unchecked`,
             // since that would actually be lying from a language perspective;
             // the value seems to only settle on being !0 after some time
             // (something about the _COMM_PAGE_CPU_QUIESCENT_COUNTER?)
             //
             // TODO: Investigate this further!
-            // std::hint::assert_unchecked(atomic_predicate.load(Ordering::Acquire) == !0);
+            // core::hint::assert_unchecked(atomic_predicate.load(Ordering::Acquire) == !0);
         } else {
             invoke_dispatch_once(predicate, work);
         }
@@ -196,9 +195,8 @@ impl fmt::Debug for Once {
 
 #[cfg(test)]
 mod tests {
-    use std::cell::Cell;
-    use std::mem::ManuallyDrop;
-    use std::thread;
+    use core::cell::Cell;
+    use core::mem::ManuallyDrop;
 
     use super::*;
 
@@ -249,12 +247,13 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "std")]
     fn test_threaded() {
         let once = Once::new();
 
         let num = AtomicIsize::new(0);
 
-        thread::scope(|scope| {
+        std::thread::scope(|scope| {
             scope.spawn(|| {
                 once.call_once(|| {
                     num.fetch_add(1, Ordering::Relaxed);
@@ -329,9 +328,7 @@ mod tests {
         let once = Once::new();
 
         once.call_once(|| {
-            once.call_once(|| {
-                println!("foo");
-            });
+            once.call_once(|| {});
         });
     }
 }

crates/dispatch2/src/queue.rs

@@ -1,10 +1,11 @@
 //! Dispatch queue definition.
 
-use std::borrow::{Borrow, BorrowMut};
-use std::ffi::CString;
-use std::ops::{Deref, DerefMut};
-use std::ptr::NonNull;
-use std::time::Duration;
+use alloc::boxed::Box;
+use alloc::ffi::CString;
+use core::borrow::{Borrow, BorrowMut};
+use core::ops::{Deref, DerefMut};
+use core::ptr::NonNull;
+use core::time::Duration;
 
 use super::object::{DispatchObject, QualityOfServiceClassFloorError, TargetQueueError};
 use super::utils::function_wrapper;

crates/dispatch2/src/semaphore.rs

@@ -1,6 +1,6 @@
 //! Dispatch semaphore definition.
 
-use std::time::Duration;
+use core::time::Duration;
 
 use super::ffi::*;
 use super::object::DispatchObject;

crates/dispatch2/src/utils.rs

@@ -1,6 +1,6 @@
-use std::time::Duration;
-
+use alloc::boxed::Box;
 use core::ffi::c_void;
+use core::time::Duration;
 
 use super::ffi::{dispatch_time, dispatch_time_t, DISPATCH_TIME_NOW};
 

framework-crates/objc2-core-graphics/translation-config.toml

@@ -24,7 +24,7 @@ struct.__IOSurface.skipped = true
 # Needs io_service_t from the kernel
 fn.CGDisplayIOServicePort.skipped = true
 
-# Needs std::ffi::VaList, currently unstable
+# Needs core::ffi::VaList, currently unstable
 fn.CGColorConversionInfoCreateFromListWithArguments.skipped = true
 
 # Unknown how to handle the calling convention here?