From 970040bdcdf37ed549c439798463f85264ac3b93 Mon Sep 17 00:00:00 2001
From: silvanshade <silvanshade@users.noreply.github.com>
Date: Sun, 29 Jan 2023 10:47:17 -0700
Subject: [PATCH] Allow ivar names to be elided

---
 crates/icrate/examples/delegate.rs         | 12 +++++------
 crates/objc2/src/macros/__field_helpers.rs | 23 ++++++++++++++++------
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/crates/icrate/examples/delegate.rs b/crates/icrate/examples/delegate.rs
index c7f75b6a2..e2dbddb48 100644
--- a/crates/icrate/examples/delegate.rs
+++ b/crates/icrate/examples/delegate.rs
@@ -14,12 +14,12 @@ extern "C" {}
 declare_class!(
     #[derive(Debug)]
     struct CustomAppDelegate {
-        pub ivar: IvarEncode<u8, "_ivar">,
-        another_ivar: IvarBool<"_another_ivar">,
-        box_ivar: IvarDrop<Box<i32>, "_box_ivar">,
-        maybe_box_ivar: IvarDrop<Option<Box<i32>>, "_maybe_box_ivar">,
-        id_ivar: IvarDrop<Id<NSString, Shared>, "_id_ivar">,
-        maybe_id_ivar: IvarDrop<Option<Id<NSString, Shared>>, "_maybe_id_ivar">,
+        pub ivar: IvarEncode<u8>,
+        another_ivar: IvarBool,
+        box_ivar: IvarDrop<Box<i32>>,
+        maybe_box_ivar: IvarDrop<Option<Box<i32>>>,
+        id_ivar: IvarDrop<Id<NSString, Shared>>,
+        maybe_id_ivar: IvarDrop<Option<Id<NSString, Shared>>>,
     }
 
     mod ivars;
diff --git a/crates/objc2/src/macros/__field_helpers.rs b/crates/objc2/src/macros/__field_helpers.rs
index 3a18a3b82..46ea20106 100644
--- a/crates/objc2/src/macros/__field_helpers.rs
+++ b/crates/objc2/src/macros/__field_helpers.rs
@@ -180,7 +180,7 @@ macro_rules! __parse_fields {
     (
         (
             $(#[$m:meta])*
-            $vis:vis $field_name:ident: IvarDrop<$ty:ty, $ivar_name:literal>
+            $vis:vis $field_name:ident: IvarDrop<$ty:ty $(, $ivar_name:literal)?>
             $(, $($rest_fields:tt)*)?
         )
         ($($ivar_helper_module_v:vis mod $ivar_helper_module:ident)?)
@@ -208,7 +208,7 @@ macro_rules! __parse_fields {
                 // - Caller upholds that the ivars are properly initialized.
                 unsafe impl $crate::declare::IvarType for $field_name {
                     type Type = IvarDrop<$ty>;
-                    const NAME: &'static $crate::__macro_helpers::str = $ivar_name;
+                    const NAME: &'static $crate::__macro_helpers::str = $crate::__select_ivar_name!($field_name; $($ivar_name)?);
                 }
             ) ($($ivar_type_name)* $field_name)
             (
@@ -227,7 +227,7 @@ macro_rules! __parse_fields {
     (
         (
             $(#[$m:meta])*
-            $vis:vis $field_name:ident: IvarEncode<$ty:ty, $ivar_name:literal>
+            $vis:vis $field_name:ident: IvarEncode<$ty:ty $(, $ivar_name:literal)?>
             $(, $($rest_fields:tt)*)?
         )
         ($($ivar_helper_module_v:vis mod $ivar_helper_module:ident)?)
@@ -252,7 +252,7 @@ macro_rules! __parse_fields {
                 // SAFETY: See above
                 unsafe impl $crate::declare::IvarType for $field_name {
                     type Type = IvarEncode<$ty>;
-                    const NAME: &'static $crate::__macro_helpers::str = $ivar_name;
+                    const NAME: &'static $crate::__macro_helpers::str = $crate::__select_ivar_name!($field_name; $($ivar_name)?);
                 }
             ) ($($ivar_type_name)* $field_name)
             (
@@ -271,7 +271,7 @@ macro_rules! __parse_fields {
     (
         (
             $(#[$m:meta])*
-            $vis:vis $field_name:ident: IvarBool<$ivar_name:literal>
+            $vis:vis $field_name:ident: IvarBool$(<$ivar_name:literal>)?
             $(, $($rest_fields:tt)*)?
         )
         ($($ivar_helper_module_v:vis mod $ivar_helper_module:ident)?)
@@ -296,7 +296,7 @@ macro_rules! __parse_fields {
                 // SAFETY: See above
                 unsafe impl $crate::declare::IvarType for $field_name {
                     type Type = IvarBool;
-                    const NAME: &'static $crate::__macro_helpers::str = $ivar_name;
+                    const NAME: &'static $crate::__macro_helpers::str = $crate::__select_ivar_name!($field_name; $($ivar_name)?);
                 }
             ) ($($ivar_type_name)* $field_name)
             (
@@ -349,3 +349,14 @@ macro_rules! __parse_fields {
         }
     }
 }
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __select_ivar_name {
+    ($field_name:ident; $ivar_name:literal) => {
+        $ivar_name
+    };
+    ($field_name:ident;) => {
+        concat!('_', stringify!($field_name))
+    };
+}