Added Objc category inheritance

CHANGELOG.md

@@ -139,6 +139,7 @@
 # Unreleased
 
 ## Added
+* Objective-c bindings generate impl blocks for categories inherited through parent classes ([#1784][]).
 
 ## Fixed
 

src/codegen/mod.rs

@@ -4185,6 +4185,27 @@ impl CodeGenerator for ObjCInterface {
                         result.push(impl_trait);
                     }
                 }
+                for (category_name, category_template_names) in
+                    &parent.categories
+                {
+                    let category_name = ctx.rust_ident(category_name);
+                    let impl_trait = if !category_template_names.is_empty() {
+                        let template_names: Vec<Ident> =
+                            category_template_names
+                                .iter()
+                                .map(|g| ctx.rust_ident(g))
+                                .collect();
+                        quote! {
+                            impl <#(#template_names :'static),*> #category_name <#(#template_names),*> for #class_name {
+                            }
+                        }
+                    } else {
+                        quote! {
+                            impl #category_name for #class_name { }
+                        }
+                    };
+                    result.push(impl_trait);
+                }
                 if !parent.is_template() {
                     let parent_struct_name = parent.name();
                     let child_struct_name = self.name();
@@ -4216,7 +4237,10 @@ impl CodeGenerator for ObjCInterface {
                         }
                     };
                     result.push(try_into_block);
-                }
+                    parent.parent_class
+                } else {
+                    None
+                };
             }
         }
 

src/ir/context.rs

@@ -875,6 +875,11 @@ If you encounter an error missing from this list, please file an issue or a PR!"
         })
     }
 
+    /// Get a mutable reference to a given ItemId.
+    pub fn get_item_mut(&mut self, id: ItemId) -> Option<&mut Item> {
+        self.items.get_mut(id.0)?.as_mut()
+    }
+
     /// Have we collected all unresolved type references yet?
     pub fn collected_typerefs(&self) -> bool {
         self.collected_typerefs

src/ir/objc.rs

@@ -1,10 +1,10 @@
 //! Objective C types
 
-use super::context::{BindgenContext, ItemId};
+use super::context::{BindgenContext, ItemId, TypeId};
 use super::function::FunctionSig;
 use super::item::Item;
 use super::traversal::{Trace, Tracer};
-use super::ty::TypeKind;
+use super::ty::{Type, TypeKind};
 use crate::clang;
 use crate::parse::ClangItemParser;
 use clang_sys::CXChildVisit_Continue;
@@ -37,6 +37,9 @@ pub struct ObjCInterface {
     /// The list of protocols that this interface conforms to.
     pub conforms_to: Vec<ItemId>,
 
+    /// The list of categories (and the template tags) that this interface is extended by.
+    pub categories: Vec<(String, Vec<String>)>,
+
     /// The direct parent for this interface.
     pub parent_class: Option<ItemId>,
 
@@ -68,6 +71,7 @@ impl ObjCInterface {
         ObjCInterface {
             name: name.to_owned(),
             category: None,
+            categories: Vec::new(),
             is_protocol: false,
             template_names: Vec::new(),
             parent_class: None,
@@ -133,14 +137,25 @@ impl ObjCInterface {
             interface.is_protocol = true;
         }
 
+        // This is the ItemId for the real interface to which a category extends.  We must make it
+        // an optional, set it when we visit the ObjCCategoryDecl and then use it after we've
+        // visited the entire tree. We must do it in this order to ensure that this interface has
+        // all the template tags assigned to it.
+        let mut real_interface_id_for_category: Option<ItemId> = None;
+
         cursor.visit(|c| {
             match c.kind() {
                 CXCursor_ObjCClassRef => {
                     if cursor.kind() == CXCursor_ObjCCategoryDecl {
                         // We are actually a category extension, and we found the reference
-                        // to the original interface, so name this interface approriately
+                        // to the original interface, so name this interface approriately.
+
                         interface.name = c.spelling();
                         interface.category = Some(cursor.spelling());
+                        real_interface_id_for_category = Some(
+                            Item::from_ty_or_ref(c.cur_type(), c, None, ctx)
+                                .into(),
+                        );
                     }
                 }
                 CXCursor_ObjCProtocolRef => {
@@ -200,9 +215,61 @@ impl ObjCInterface {
             }
             CXChildVisit_Continue
         });
+
+        if interface.is_category() {
+            // If this interface is a category, we need to find the interface that this category
+            // extends.
+            if let Some(ref mut ty) =
+                Self::get_parent_ty(ctx, real_interface_id_for_category)
+            {
+                if let TypeKind::ObjCInterface(ref mut real_interface) =
+                    ty.kind_mut()
+                {
+                    if !real_interface.is_category() {
+                        real_interface.categories.push((
+                            interface.rust_name(),
+                            interface.template_names.clone(),
+                        ));
+                    }
+                }
+            }
+        }
         Some(interface)
     }
 
+    fn get_parent_ty(
+        ctx: &mut BindgenContext,
+        parent_id: Option<ItemId>,
+    ) -> Option<&mut Type> {
+        // This is pretty gross but using the ItemResolver doesn't yield a mutable reference.
+        let mut ty = ctx.resolve_item_fallible(parent_id?)?.kind().as_type()?;
+        let mut item_id: Option<&TypeId> = None;
+        loop {
+            match ty.kind() {
+                TypeKind::ResolvedTypeRef(ref_id) => {
+                    let ref_item: ItemId = ref_id.into();
+                    ty = ctx
+                        .resolve_item_fallible(ref_item)?
+                        .kind()
+                        .as_type()?;
+                    //ty = ref_item.kind().as_type()()?;;
+                    item_id = Some(ref_id);
+                }
+                TypeKind::ObjCInterface(..) => {
+                    break;
+                }
+                _ => return None,
+            };
+        }
+
+        let real_interface_id: ItemId = item_id?.into();
+        let ty = ctx
+            .get_item_mut(real_interface_id)?
+            .kind_mut()
+            .as_type_mut()?;
+        return Some(ty);
+    }
+
     fn add_method(&mut self, method: ObjCMethod) {
         if method.is_class_method {
             self.class_methods.push(method);

src/ir/ty.rs

@@ -588,7 +588,7 @@ pub enum TypeKind {
     /// A compound type, that is, a class, struct, or union.
     Comp(CompInfo),
 
-    /// An opaque type that we just don't understand. All usage of this shoulf
+    /// An opaque type that we just don't understand. All usage of this should
     /// result in an opaque blob of bytes generated from the containing type's
     /// layout.
     Opaque,

tests/expectations/tests/objc_category_inheritance.rs

@@ -0,0 +1,67 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+#![cfg(target_os = "macos")]
+
+#[macro_use]
+extern crate objc;
+#[allow(non_camel_case_types)]
+pub type id = *mut objc::runtime::Object;
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Foo(pub id);
+impl std::ops::Deref for Foo {
+    type Target = objc::runtime::Object;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+unsafe impl objc::Message for Foo {}
+impl Foo {
+    pub fn alloc() -> Self {
+        Self(unsafe { msg_send!(objc::class!(Foo), alloc) })
+    }
+}
+impl IFoo for Foo {}
+pub trait IFoo: Sized + std::ops::Deref {}
+impl Foo_BarCategory for Foo {}
+pub trait Foo_BarCategory: Sized + std::ops::Deref {}
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Bar(pub id);
+impl std::ops::Deref for Bar {
+    type Target = objc::runtime::Object;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+unsafe impl objc::Message for Bar {}
+impl Bar {
+    pub fn alloc() -> Self {
+        Self(unsafe { msg_send!(objc::class!(Bar), alloc) })
+    }
+}
+impl IFoo for Bar {}
+impl Foo_BarCategory for Bar {}
+impl From<Bar> for Foo {
+    fn from(child: Bar) -> Foo {
+        Foo(child.0)
+    }
+}
+impl std::convert::TryFrom<Foo> for Bar {
+    type Error = &'static str;
+    fn try_from(parent: Foo) -> Result<Bar, Self::Error> {
+        let is_kind_of: bool =
+            unsafe { msg_send!(parent, isKindOfClass: class!(Bar)) };
+        if is_kind_of {
+            Ok(Bar(parent.0))
+        } else {
+            Err("This Foo cannot be downcasted to Bar")
+        }
+    }
+}
+impl IBar for Bar {}
+pub trait IBar: Sized + std::ops::Deref {}

tests/expectations/tests/objc_category_template_inheritance.rs

@@ -0,0 +1,50 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+#![cfg(target_os = "macos")]
+
+#[macro_use]
+extern crate objc;
+#[allow(non_camel_case_types)]
+pub type id = *mut objc::runtime::Object;
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Foo(pub id);
+impl std::ops::Deref for Foo {
+    type Target = objc::runtime::Object;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+unsafe impl objc::Message for Foo {}
+impl Foo {
+    pub fn alloc() -> Self {
+        Self(unsafe { msg_send!(objc::class!(Foo), alloc) })
+    }
+}
+impl<ObjectType: 'static> IFoo<ObjectType> for Foo {}
+pub trait IFoo<ObjectType>: Sized + std::ops::Deref {}
+impl<ObjectType: 'static> Foo_Baz<ObjectType> for Foo {}
+pub trait Foo_Baz<ObjectType>: Sized + std::ops::Deref {}
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Bar(pub id);
+impl std::ops::Deref for Bar {
+    type Target = objc::runtime::Object;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+unsafe impl objc::Message for Bar {}
+impl Bar {
+    pub fn alloc() -> Self {
+        Self(unsafe { msg_send!(objc::class!(Bar), alloc) })
+    }
+}
+impl<ObjectType: 'static> IFoo<ObjectType> for Bar {}
+impl<ObjectType: 'static> Foo_Baz<ObjectType> for Bar {}
+impl<ObjectType: 'static> IBar<ObjectType> for Bar {}
+pub trait IBar<ObjectType>: Sized + std::ops::Deref {}

tests/expectations/tests/objc_template_inheritance.rs

@@ -0,0 +1,47 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+#![cfg(target_os = "macos")]
+
+#[macro_use]
+extern crate objc;
+#[allow(non_camel_case_types)]
+pub type id = *mut objc::runtime::Object;
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Foo(pub id);
+impl std::ops::Deref for Foo {
+    type Target = objc::runtime::Object;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+unsafe impl objc::Message for Foo {}
+impl Foo {
+    pub fn alloc() -> Self {
+        Self(unsafe { msg_send!(objc::class!(Foo), alloc) })
+    }
+}
+impl<ObjectType: 'static> IFoo<ObjectType> for Foo {}
+pub trait IFoo<ObjectType>: Sized + std::ops::Deref {}
+#[repr(transparent)]
+#[derive(Clone)]
+pub struct Bar(pub id);
+impl std::ops::Deref for Bar {
+    type Target = objc::runtime::Object;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+unsafe impl objc::Message for Bar {}
+impl Bar {
+    pub fn alloc() -> Self {
+        Self(unsafe { msg_send!(objc::class!(Bar), alloc) })
+    }
+}
+impl<ObjectType: 'static> IFoo<ObjectType> for Bar {}
+impl<ObjectType: 'static> IBar<ObjectType> for Bar {}
+pub trait IBar<ObjectType>: Sized + std::ops::Deref {}

tests/headers/objc_category_inheritance.h

@@ -0,0 +1,11 @@
+// bindgen-flags: --objc-extern-crate -- -x objective-c
+// bindgen-osx-only
+
+@interface Foo
+@end
+
+@interface Foo (BarCategory)
+@end
+
+@interface Bar: Foo
+@end

tests/headers/objc_category_template_inheritance.h

@@ -0,0 +1,11 @@
+// bindgen-flags: --objc-extern-crate -- -x objective-c
+// bindgen-osx-only
+
+@interface Foo<__covariant ObjectType>
+@end
+
+@interface Foo<__covariant ObjectType> (Baz)
+@end
+
+@interface Bar<__covariant ObjectType>: Foo
+@end

tests/headers/objc_template_inheritance.h

@@ -0,0 +1,8 @@
+// bindgen-flags: --objc-extern-crate -- -x objective-c
+// bindgen-osx-only
+
+@interface Foo<__covariant ObjectType>
+@end
+
+@interface Bar<__covariant ObjectType>: Foo
+@end