Move VARIANT support to the windows crate (#3282)

Author: kennykerr

crates/libs/bindgen/src/lib.rs

@@ -85,7 +85,7 @@ where
     let output = canonicalize(output)?;
 
     let input = read_input(&input)?;
-    let reader = metadata::Reader::filter(input, &include, &exclude, &config);
+    let reader = metadata::Reader::filter(input, &include, &exclude);
 
     match extension(&output) {
         "rs" => rust::from_reader(reader, config, &output)?,

crates/libs/bindgen/src/metadata.rs

@@ -465,8 +465,6 @@ pub fn type_is_borrowed(ty: &Type) -> bool {
     match ty {
         Type::TypeDef(row, _) => !type_def_is_blittable(*row),
         Type::Name(TypeName::BSTR)
-        | Type::Name(TypeName::VARIANT)
-        | Type::Name(TypeName::PROPVARIANT)
         | Type::Const(TypeName::PSTR)
         | Type::Const(TypeName::PWSTR)
         | Type::Object
@@ -590,8 +588,6 @@ pub fn type_is_blittable(ty: &Type) -> bool {
         Type::TypeDef(row, _) => type_def_is_blittable(*row),
         Type::String
         | Type::Name(TypeName::BSTR)
-        | Type::Name(TypeName::VARIANT)
-        | Type::Name(TypeName::PROPVARIANT)
         | Type::Object
         | Type::Name(TypeName::IUnknown)
         | Type::GenericParam(_) => false,
@@ -606,8 +602,6 @@ fn type_is_copyable(ty: &Type) -> bool {
         Type::TypeDef(row, _) => type_def_is_copyable(*row),
         Type::String
         | Type::Name(TypeName::BSTR)
-        | Type::Name(TypeName::VARIANT)
-        | Type::Name(TypeName::PROPVARIANT)
         | Type::Object
         | Type::Name(TypeName::IUnknown)
         | Type::GenericParam(_) => false,
@@ -623,7 +617,7 @@ pub fn type_def_is_blittable(row: TypeDef) -> bool {
             if row.flags().contains(TypeAttributes::WindowsRuntime) {
                 row.fields().all(|field| field_is_blittable(field, row))
             } else {
-                true
+                !matches!(row.type_name(), TypeName::VARIANT | TypeName::PROPVARIANT)
             }
         }
         TypeKind::Enum => true,

crates/libs/bindgen/src/rust/structs.rs

@@ -217,6 +217,10 @@ fn gen_clone(
             .flags()
             .contains(metadata::TypeAttributes::WindowsRuntime)
         || def.class_layout().is_some()
+        || matches!(
+            def.type_name(),
+            metadata::TypeName::VARIANT | metadata::TypeName::PROPVARIANT
+        )
     {
         quote! {}
     } else {

crates/libs/bindgen/src/rust/writer.rs

@@ -159,14 +159,6 @@ impl Writer {
                 let crate_name = self.crate_name();
                 quote! { #crate_name BSTR }
             }
-            metadata::Type::Name(metadata::TypeName::VARIANT) => {
-                let crate_name = self.crate_name();
-                quote! { #crate_name VARIANT }
-            }
-            metadata::Type::Name(metadata::TypeName::PROPVARIANT) => {
-                let crate_name = self.crate_name();
-                quote! { #crate_name PROPVARIANT }
-            }
             metadata::Type::Object => {
                 if self.sys {
                     quote! { *mut core::ffi::c_void }
@@ -271,12 +263,6 @@ impl Writer {
             metadata::Type::Name(metadata::TypeName::BSTR) => {
                 quote! { core::mem::MaybeUninit<windows_core::BSTR> }
             }
-            metadata::Type::Name(metadata::TypeName::VARIANT) => {
-                quote! { core::mem::MaybeUninit<windows_core::VARIANT> }
-            }
-            metadata::Type::Name(metadata::TypeName::PROPVARIANT) => {
-                quote! { core::mem::MaybeUninit<windows_core::PROPVARIANT> }
-            }
             metadata::Type::Win32Array(kind, len) => {
                 let name = self.type_abi_name(kind);
                 let len = Literal::usize_unsuffixed(*len);