1 files changed, 142 insertions, 0 deletions
diff --git a/third_party/rust/bindgen/codegen/impl_partialeq.rs b/third_party/rust/bindgen/codegen/impl_partialeq.rs
new file mode 100644
index 0000000000..960306ffc6
--- /dev/null
+++ b/third_party/rust/bindgen/codegen/impl_partialeq.rs
@@ -0,0 +1,142 @@
+use crate::ir::comp::{CompInfo, CompKind, Field, FieldMethods};
+use crate::ir::context::BindgenContext;
+use crate::ir::item::{IsOpaque, Item};
+use crate::ir::ty::{TypeKind, RUST_DERIVE_IN_ARRAY_LIMIT};
+
+/// Generate a manual implementation of `PartialEq` trait for the
+/// specified compound type.
+pub fn gen_partialeq_impl(
+    ctx: &BindgenContext,
+    comp_info: &CompInfo,
+    item: &Item,
+    ty_for_impl: &proc_macro2::TokenStream,
+) -> Option<proc_macro2::TokenStream> {
+    let mut tokens = vec![];
+
+    if item.is_opaque(ctx, &()) {
+        tokens.push(quote! {
+            &self._bindgen_opaque_blob[..] == &other._bindgen_opaque_blob[..]
+        });
+    } else if comp_info.kind() == CompKind::Union {
+        assert!(!ctx.options().rust_features().untagged_union);
+        tokens.push(quote! {
+            &self.bindgen_union_field[..] == &other.bindgen_union_field[..]
+        });
+    } else {
+        for base in comp_info.base_members().iter() {
+            if !base.requires_storage(ctx) {
+                continue;
+            }
+
+            let ty_item = ctx.resolve_item(base.ty);
+            let field_name = &base.field_name;
+
+            if ty_item.is_opaque(ctx, &()) {
+                let field_name = ctx.rust_ident(field_name);
+                tokens.push(quote! {
+                    &self. #field_name [..] == &other. #field_name [..]
+                });
+            } else {
+                tokens.push(gen_field(ctx, ty_item, field_name));
+            }
+        }
+
+        for field in comp_info.fields() {
+            match *field {
+                Field::DataMember(ref fd) => {
+                    let ty_item = ctx.resolve_item(fd.ty());
+                    let name = fd.name().unwrap();
+                    tokens.push(gen_field(ctx, ty_item, name));
+                }
+                Field::Bitfields(ref bu) => {
+                    for bitfield in bu.bitfields() {
+                        if bitfield.name().is_some() {
+                            let getter_name = bitfield.getter_name();
+                            let name_ident = ctx.rust_ident_raw(getter_name);
+                            tokens.push(quote! {
+                                self.#name_ident () == other.#name_ident ()
+                            });
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    Some(quote! {
+        fn eq(&self, other: & #ty_for_impl) -> bool {
+            #( #tokens )&&*
+        }
+    })
+}
+
+fn gen_field(
+    ctx: &BindgenContext,
+    ty_item: &Item,
+    name: &str,
+) -> proc_macro2::TokenStream {
+    fn quote_equals(
+        name_ident: proc_macro2::Ident,
+    ) -> proc_macro2::TokenStream {
+        quote! { self.#name_ident == other.#name_ident }
+    }
+
+    let name_ident = ctx.rust_ident(name);
+    let ty = ty_item.expect_type();
+
+    match *ty.kind() {
+        TypeKind::Void |
+        TypeKind::NullPtr |
+        TypeKind::Int(..) |
+        TypeKind::Complex(..) |
+        TypeKind::Float(..) |
+        TypeKind::Enum(..) |
+        TypeKind::TypeParam |
+        TypeKind::UnresolvedTypeRef(..) |
+        TypeKind::Reference(..) |
+        TypeKind::ObjCInterface(..) |
+        TypeKind::ObjCId |
+        TypeKind::ObjCSel |
+        TypeKind::Comp(..) |
+        TypeKind::Pointer(_) |
+        TypeKind::Function(..) |
+        TypeKind::Opaque => quote_equals(name_ident),
+
+        TypeKind::TemplateInstantiation(ref inst) => {
+            if inst.is_opaque(ctx, ty_item) {
+                quote! {
+                    &self. #name_ident [..] == &other. #name_ident [..]
+                }
+            } else {
+                quote_equals(name_ident)
+            }
+        }
+
+        TypeKind::Array(_, len) => {
+            if len <= RUST_DERIVE_IN_ARRAY_LIMIT ||
+                ctx.options().rust_features().larger_arrays
+            {
+                quote_equals(name_ident)
+            } else {
+                quote! {
+                    &self. #name_ident [..] == &other. #name_ident [..]
+                }
+            }
+        }
+        TypeKind::Vector(_, len) => {
+            let self_ids = 0..len;
+            let other_ids = 0..len;
+            quote! {
+                #(self.#self_ids == other.#other_ids &&)* true
+            }
+        }
+
+        TypeKind::ResolvedTypeRef(t) |
+        TypeKind::TemplateAlias(t, _) |
+        TypeKind::Alias(t) |
+        TypeKind::BlockPointer(t) => {
+            let inner_item = ctx.resolve_item(t);
+            gen_field(ctx, inner_item, name)
+        }
+    }
+}