From 0a1b0d6f1bbe5a3e60903a9416543e408d8581c5 Mon Sep 17 00:00:00 2001
From: Steven Sheldon <steven@sasheldon.com>
Date: Wed, 16 Oct 2019 06:50:58 -0700
Subject: [PATCH] Fixes so the compiler can infer msg_send! return types

Currently, due to a quirk in Rust's type inference interacting with the
structure of the msg_send! macro, a () return type will be inferred when
the compiler cannot otherwise determine the return type. This behavior
is expected to change, and in the future could resolve to a ! return
type, which results in undefined behavior.

Linting has previously been added for this in rust-lang/rust#39216, but
it did not catch these cases due to SSheldon/rust-objc#62. An upcoming
version of objc will be fixed to stop hiding these errors, at which
point they will become compile errors.

This change fixes these errors and allows cocoa to compile with the
fixed version of objc.
---
 cocoa/src/appkit.rs       | 14 +++++++-------
 cocoa/src/quartzcore.rs   |  4 ++--
 cocoa/tests/foundation.rs |  2 +-
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/cocoa/src/appkit.rs b/cocoa/src/appkit.rs
index 8e96460da..53afce4ad 100644
--- a/cocoa/src/appkit.rs
+++ b/cocoa/src/appkit.rs
@@ -549,7 +549,7 @@ pub trait NSPasteboard: Sized {
 
 impl NSPasteboard for id {
     unsafe fn releaseGlobally(self) {
-        msg_send![self, releaseGlobally];
+        msg_send![self, releaseGlobally]
     }
 
     unsafe fn clearContents(self) -> NSInteger {
@@ -1547,11 +1547,11 @@ impl NSWindow for id {
     }
 
     unsafe fn setTabbingMode_(self, tabbingMode: NSWindowTabbingMode) {
-        msg_send![self, setTabbingMode: tabbingMode];
+        msg_send![self, setTabbingMode: tabbingMode]
     }
 
     unsafe fn addTabbedWindow_ordered_(self, window: id, ordering_mode: NSWindowOrderingMode) {
-        msg_send![self, addTabbedWindow:window ordered: ordering_mode];
+        msg_send![self, addTabbedWindow:window ordered: ordering_mode]
     }
 
     unsafe fn toggleTabBar_(self, sender: id) {
@@ -2977,7 +2977,7 @@ impl NSButton for id {
         msg_send![self, initWithFrame:frameRect]
     }
     unsafe fn setBezelStyle_(self, style: NSBezelStyle) {
-        msg_send![self, setBezelStyle:style];
+        msg_send![self, setBezelStyle:style]
     }
     unsafe fn setTitle_(self, title: id /* (NSString*) */) {
         msg_send![self, setTitle:title]
@@ -2990,7 +2990,7 @@ impl NSButton for id {
     }
 
     unsafe fn setAction_(self, selector: objc::runtime::Sel /* (Instance method *) */) {
-        msg_send![self, setAction:selector];
+        msg_send![self, setAction:selector]
     }
 }
 
@@ -3589,10 +3589,10 @@ impl NSTextField for id {
         msg_send![self, initWithFrame:frameRect]
     }
     unsafe fn setEditable_(self, editable: BOOL) {
-        msg_send![self, setEditable:editable];
+        msg_send![self, setEditable:editable]
     }
     unsafe fn setStringValue_(self, label: id) {
-        msg_send![self, setStringValue:label];
+        msg_send![self, setStringValue:label]
     }
 }
 
diff --git a/cocoa/src/quartzcore.rs b/cocoa/src/quartzcore.rs
index e139147d4..5a63f4acd 100644
--- a/cocoa/src/quartzcore.rs
+++ b/cocoa/src/quartzcore.rs
@@ -889,7 +889,7 @@ impl CALayer {
     #[inline]
     pub fn set_should_rasterize(&self, flag: bool) {
         unsafe {
-            msg_send![self.id(), setShouldRasterize:(flag as BOOL)];
+            msg_send![self.id(), setShouldRasterize:(flag as BOOL)]
         }
     }
 
@@ -1459,7 +1459,7 @@ impl CARenderer {
                 Some(ref layer) => layer.id(),
                 None => nil,
             };
-            msg_send![self.id(), setLayer:layer];
+            msg_send![self.id(), setLayer:layer]
         }
     }
 
diff --git a/cocoa/tests/foundation.rs b/cocoa/tests/foundation.rs
index 219a3b902..c49150145 100644
--- a/cocoa/tests/foundation.rs
+++ b/cocoa/tests/foundation.rs
@@ -100,7 +100,7 @@ mod foundation {
                 let mut_components: id = msg_send![components, mutableCopy];
                 let mut iter = mut_components.iter();
                 iter.next();
-                msg_send![mut_components, removeObjectAtIndex:1];
+                let () = msg_send![mut_components, removeObjectAtIndex:1];
                 iter.next();
             }
         }