744 lines
21 KiB
Rust
744 lines
21 KiB
Rust
use aster;
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use syntax::ast::{
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Ident,
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MetaItem,
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Item,
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};
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use syntax::ast;
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use syntax::codemap::Span;
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use syntax::ext::base::{Annotatable, ExtCtxt};
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use syntax::ext::build::AstBuilder;
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use syntax::ptr::P;
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use attr;
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use error::Error;
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pub fn expand_derive_serialize(
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cx: &mut ExtCtxt,
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span: Span,
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meta_item: &MetaItem,
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annotatable: &Annotatable,
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push: &mut FnMut(Annotatable)
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) {
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let item = match *annotatable {
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Annotatable::Item(ref item) => item,
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_ => {
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cx.span_err(
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meta_item.span,
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"`#[derive(Serialize)]` may only be applied to structs and enums");
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return;
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}
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};
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let builder = aster::AstBuilder::new().span(span);
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let impl_item = match serialize_item(cx, &builder, &item) {
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Ok(item) => item,
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Err(Error) => {
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// An error occured, but it should have been reported already.
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return;
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}
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};
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push(Annotatable::Item(impl_item))
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}
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fn serialize_item(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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item: &Item,
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) -> Result<P<ast::Item>, Error> {
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let generics = match item.node {
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ast::ItemKind::Struct(_, ref generics) => generics,
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ast::ItemKind::Enum(_, ref generics) => generics,
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_ => {
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cx.span_err(
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item.span,
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"`#[derive(Serialize)]` may only be applied to structs and enums");
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return Err(Error);
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}
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};
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let impl_generics = builder.from_generics(generics.clone())
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.add_ty_param_bound(
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builder.path().global().ids(&["serde", "ser", "Serialize"]).build()
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)
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.build();
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let ty = builder.ty().path()
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.segment(item.ident).with_generics(impl_generics.clone()).build()
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.build();
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let body = try!(serialize_body(cx,
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&builder,
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&item,
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&impl_generics,
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ty.clone()));
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let where_clause = &impl_generics.where_clause;
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Ok(quote_item!(cx,
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impl $impl_generics ::serde::ser::Serialize for $ty $where_clause {
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fn serialize<__S>(&self, serializer: &mut __S) -> ::std::result::Result<(), __S::Error>
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where __S: ::serde::ser::Serializer,
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{
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$body
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}
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}
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).unwrap())
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}
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fn serialize_body(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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item: &Item,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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) -> Result<P<ast::Expr>, Error> {
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let container_attrs = try!(attr::ContainerAttrs::from_item(cx, item));
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match item.node {
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ast::ItemKind::Struct(ref variant_data, _) => {
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serialize_item_struct(
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cx,
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builder,
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impl_generics,
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ty,
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item.span,
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variant_data,
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&container_attrs,
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)
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}
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ast::ItemKind::Enum(ref enum_def, _) => {
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serialize_item_enum(
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cx,
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builder,
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item.ident,
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impl_generics,
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ty,
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enum_def,
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&container_attrs,
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)
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}
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_ => {
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cx.span_bug(item.span,
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"expected ItemStruct or ItemEnum in #[derive(Serialize)]");
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}
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}
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}
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fn serialize_item_struct(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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span: Span,
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variant_data: &ast::VariantData,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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match *variant_data {
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ast::VariantData::Unit(_) => {
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serialize_unit_struct(
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cx,
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container_attrs,
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)
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}
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ast::VariantData::Tuple(ref fields, _) if fields.len() == 1 => {
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serialize_newtype_struct(
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cx,
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container_attrs,
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)
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}
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ast::VariantData::Tuple(ref fields, _) => {
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if fields.iter().any(|field| !field.node.kind.is_unnamed()) {
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cx.span_bug(span, "tuple struct has named fields")
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}
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serialize_tuple_struct(
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cx,
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&builder,
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impl_generics,
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ty,
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fields.len(),
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container_attrs,
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)
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}
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ast::VariantData::Struct(ref fields, _) => {
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if fields.iter().any(|field| field.node.kind.is_unnamed()) {
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cx.span_bug(span, "struct has unnamed fields")
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}
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serialize_struct(
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cx,
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&builder,
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impl_generics,
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ty,
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fields,
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container_attrs,
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)
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}
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}
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}
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fn serialize_unit_struct(
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cx: &ExtCtxt,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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let type_name = container_attrs.serialize_name_expr();
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Ok(quote_expr!(cx,
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serializer.serialize_unit_struct($type_name)
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))
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}
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fn serialize_newtype_struct(
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cx: &ExtCtxt,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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let type_name = container_attrs.serialize_name_expr();
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Ok(quote_expr!(cx,
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serializer.serialize_newtype_struct($type_name, &self.0)
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))
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}
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fn serialize_tuple_struct(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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fields: usize,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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let (visitor_struct, visitor_impl) = serialize_tuple_struct_visitor(
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cx,
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builder,
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ty.clone(),
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builder.ty()
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.ref_()
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.lifetime("'__a")
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.build_ty(ty.clone()),
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builder.id("serialize_tuple_struct_elt"),
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fields,
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impl_generics,
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);
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let type_name = container_attrs.serialize_name_expr();
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Ok(quote_expr!(cx, {
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$visitor_struct
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$visitor_impl
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serializer.serialize_tuple_struct($type_name, Visitor {
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value: self,
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state: 0,
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_structure_ty: ::std::marker::PhantomData::<&$ty>,
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})
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}))
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}
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fn serialize_struct(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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fields: &[ast::StructField],
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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let (visitor_struct, visitor_impl) = try!(serialize_struct_visitor(
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cx,
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builder,
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ty.clone(),
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builder.ty()
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.ref_()
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.lifetime("'__a")
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.build_ty(ty.clone()),
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builder.id("serialize_struct_elt"),
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fields,
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impl_generics,
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));
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let type_name = container_attrs.serialize_name_expr();
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Ok(quote_expr!(cx, {
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$visitor_struct
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$visitor_impl
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serializer.serialize_struct($type_name, Visitor {
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value: self,
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state: 0,
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_structure_ty: ::std::marker::PhantomData::<&$ty>,
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})
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}))
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}
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fn serialize_item_enum(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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type_ident: Ident,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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enum_def: &ast::EnumDef,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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let arms: Vec<_> = try!(
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enum_def.variants.iter()
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.enumerate()
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.map(|(variant_index, variant)| {
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serialize_variant(
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cx,
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builder,
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type_ident,
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impl_generics,
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ty.clone(),
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variant,
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variant_index,
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container_attrs,
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)
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})
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.collect()
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);
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Ok(quote_expr!(cx,
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match *self {
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$arms
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}
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))
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}
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fn serialize_variant(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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type_ident: Ident,
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generics: &ast::Generics,
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ty: P<ast::Ty>,
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variant: &ast::Variant,
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variant_index: usize,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<ast::Arm, Error> {
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let type_name = container_attrs.serialize_name_expr();
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let variant_ident = variant.node.name;
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let variant_attrs = try!(attr::VariantAttrs::from_variant(cx, variant));
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let variant_name = variant_attrs.serialize_name_expr();
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match variant.node.data {
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ast::VariantData::Unit(_) => {
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let pat = builder.pat().path()
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.id(type_ident).id(variant_ident)
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.build();
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Ok(quote_arm!(cx,
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$pat => {
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::serde::ser::Serializer::serialize_unit_variant(
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serializer,
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$type_name,
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$variant_index,
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$variant_name,
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)
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}
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))
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},
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ast::VariantData::Tuple(ref fields, _) if fields.len() == 1 => {
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let field = builder.id("__simple_value");
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let field = builder.pat().ref_id(field);
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let pat = builder.pat().enum_()
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.id(type_ident).id(variant_ident).build()
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.with_pats(Some(field).into_iter())
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.build();
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Ok(quote_arm!(cx,
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$pat => {
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::serde::ser::Serializer::serialize_newtype_variant(
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serializer,
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$type_name,
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$variant_index,
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$variant_name,
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__simple_value,
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)
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}
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))
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},
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ast::VariantData::Tuple(ref fields, _) => {
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let field_names: Vec<ast::Ident> = (0 .. fields.len())
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.map(|i| builder.id(format!("__field{}", i)))
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.collect();
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let pat = builder.pat().enum_()
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.id(type_ident).id(variant_ident).build()
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.with_pats(
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field_names.iter()
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.map(|field| builder.pat().ref_id(field))
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)
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.build();
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let expr = serialize_tuple_variant(
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cx,
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builder,
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type_name,
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variant_index,
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variant_name,
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generics,
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ty,
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fields,
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field_names,
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);
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Ok(quote_arm!(cx,
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$pat => { $expr }
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))
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}
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ast::VariantData::Struct(ref fields, _) => {
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let field_names: Vec<_> = (0 .. fields.len())
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.map(|i| builder.id(format!("__field{}", i)))
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.collect();
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let pat = builder.pat().struct_()
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.id(type_ident).id(variant_ident).build()
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.with_pats(
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field_names.iter()
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.zip(fields.iter())
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.map(|(id, field)| {
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let name = match field.node.kind {
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ast::NamedField(name, _) => name,
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ast::UnnamedField(_) => {
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cx.span_bug(field.span, "struct variant has unnamed fields")
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}
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};
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(name, builder.pat().ref_id(id))
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})
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)
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.build();
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let expr = try!(serialize_struct_variant(
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cx,
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builder,
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variant_index,
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variant_name,
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generics,
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ty,
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fields,
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field_names,
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container_attrs,
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));
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Ok(quote_arm!(cx,
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$pat => { $expr }
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))
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}
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}
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}
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fn serialize_tuple_variant(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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type_name: P<ast::Expr>,
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variant_index: usize,
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variant_name: P<ast::Expr>,
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generics: &ast::Generics,
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structure_ty: P<ast::Ty>,
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fields: &[ast::StructField],
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field_names: Vec<Ident>,
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) -> P<ast::Expr> {
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let variant_ty = builder.ty().tuple()
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.with_tys(
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fields.iter().map(|field| {
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builder.ty()
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.ref_()
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.lifetime("'__a")
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.build_ty(field.node.ty.clone())
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})
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)
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.build();
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let (visitor_struct, visitor_impl) = serialize_tuple_struct_visitor(
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cx,
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builder,
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structure_ty.clone(),
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variant_ty,
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builder.id("serialize_tuple_variant_elt"),
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fields.len(),
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generics,
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);
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let value_expr = builder.expr().tuple()
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.with_exprs(
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field_names.iter().map(|field| {
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builder.expr().id(field)
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})
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)
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.build();
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quote_expr!(cx, {
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$visitor_struct
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$visitor_impl
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serializer.serialize_tuple_variant($type_name, $variant_index, $variant_name, Visitor {
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value: $value_expr,
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state: 0,
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_structure_ty: ::std::marker::PhantomData::<&$structure_ty>,
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})
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})
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}
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fn serialize_struct_variant(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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variant_index: usize,
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variant_name: P<ast::Expr>,
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generics: &ast::Generics,
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ty: P<ast::Ty>,
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fields: &[ast::StructField],
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field_names: Vec<Ident>,
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container_attrs: &attr::ContainerAttrs,
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) -> Result<P<ast::Expr>, Error> {
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let variant_generics = builder.generics()
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.with(generics.clone())
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.add_lifetime_bound("'__serde_variant")
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.lifetime_name("'__serde_variant")
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.build();
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let variant_struct = builder.item().struct_("__VariantStruct")
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.with_generics(variant_generics.clone())
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.with_fields(
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fields.iter().map(|field| {
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builder.struct_field(field.node.ident().expect("struct has unnamed fields"))
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.with_attrs(field.node.attrs.iter().cloned())
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.ty()
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.ref_()
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.lifetime("'__serde_variant")
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.build_ty(field.node.ty.clone())
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})
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)
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.field("__serde_container_ty")
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.ty().phantom_data().build(ty.clone())
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.build();
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let variant_expr = builder.expr().struct_id("__VariantStruct")
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.with_id_exprs(
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fields.iter()
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.zip(field_names.iter())
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.map(|(field, field_name)| {
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(
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field.node.ident().expect("struct has unnamed fields"),
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builder.expr().id(field_name),
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)
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})
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)
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.field("__serde_container_ty").path()
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.global()
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.id("std").id("marker")
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.segment("PhantomData")
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.with_ty(ty.clone())
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.build()
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.build()
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.build();
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let variant_ty = builder.ty().path()
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.segment("__VariantStruct")
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.with_generics(variant_generics.clone())
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.build()
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.build();
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|
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let (visitor_struct, visitor_impl) = try!(serialize_struct_visitor(
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cx,
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builder,
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variant_ty.clone(),
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variant_ty.clone(),
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builder.id("serialize_struct_variant_elt"),
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fields,
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&variant_generics,
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));
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let container_name = container_attrs.serialize_name_expr();
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Ok(quote_expr!(cx, {
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$variant_struct
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$visitor_struct
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$visitor_impl
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serializer.serialize_struct_variant(
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$container_name,
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$variant_index,
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$variant_name,
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Visitor {
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value: $variant_expr,
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state: 0,
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_structure_ty: ::std::marker::PhantomData,
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},
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)
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}))
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}
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|
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fn serialize_tuple_struct_visitor(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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structure_ty: P<ast::Ty>,
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variant_ty: P<ast::Ty>,
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serializer_method: ast::Ident,
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fields: usize,
|
|
generics: &ast::Generics
|
|
) -> (P<ast::Item>, P<ast::Item>) {
|
|
let arms: Vec<ast::Arm> = (0 .. fields)
|
|
.map(|i| {
|
|
let expr = builder.expr().method_call(serializer_method)
|
|
.id("serializer")
|
|
.arg().ref_().tup_field(i).field("value").self_()
|
|
.build();
|
|
|
|
quote_arm!(cx,
|
|
$i => {
|
|
self.state += 1;
|
|
Ok(Some(try!($expr)))
|
|
}
|
|
)
|
|
})
|
|
.collect();
|
|
|
|
let visitor_impl_generics = builder.from_generics(generics.clone())
|
|
.add_lifetime_bound("'__a")
|
|
.lifetime_name("'__a")
|
|
.build();
|
|
|
|
let where_clause = &visitor_impl_generics.where_clause;
|
|
|
|
let visitor_generics = builder.from_generics(visitor_impl_generics.clone())
|
|
.strip_bounds()
|
|
.build();
|
|
|
|
(
|
|
quote_item!(cx,
|
|
struct Visitor $visitor_impl_generics $where_clause {
|
|
state: usize,
|
|
value: $variant_ty,
|
|
_structure_ty: ::std::marker::PhantomData<&'__a $structure_ty>,
|
|
}
|
|
).unwrap(),
|
|
|
|
quote_item!(cx,
|
|
impl $visitor_impl_generics ::serde::ser::SeqVisitor
|
|
for Visitor $visitor_generics
|
|
$where_clause {
|
|
#[inline]
|
|
fn visit<S>(&mut self, serializer: &mut S) -> ::std::result::Result<Option<()>, S::Error>
|
|
where S: ::serde::ser::Serializer
|
|
{
|
|
match self.state {
|
|
$arms
|
|
_ => Ok(None)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn len(&self) -> Option<usize> {
|
|
Some($fields)
|
|
}
|
|
}
|
|
).unwrap(),
|
|
)
|
|
}
|
|
|
|
fn serialize_struct_visitor(
|
|
cx: &ExtCtxt,
|
|
builder: &aster::AstBuilder,
|
|
structure_ty: P<ast::Ty>,
|
|
variant_ty: P<ast::Ty>,
|
|
serializer_method: ast::Ident,
|
|
fields: &[ast::StructField],
|
|
generics: &ast::Generics,
|
|
) -> Result<(P<ast::Item>, P<ast::Item>), Error> {
|
|
let field_attrs = try!(
|
|
attr::get_struct_field_attrs(cx, &structure_ty, generics, fields)
|
|
);
|
|
|
|
let arms: Vec<ast::Arm> = fields.iter().zip(field_attrs.iter())
|
|
.filter(|&(_, ref field_attr)| !field_attr.skip_serializing_field())
|
|
.enumerate()
|
|
.map(|(i, (ref field, ref field_attr))| {
|
|
let name = field.node.ident().expect("struct has unnamed field");
|
|
|
|
let key_expr = field_attr.serialize_name_expr();
|
|
|
|
let stmt = if let Some(expr) = field_attr.skip_serializing_field_if() {
|
|
Some(quote_stmt!(cx, if $expr { continue; }))
|
|
} else {
|
|
None
|
|
};
|
|
|
|
let field_expr = match field_attr.serialize_with() {
|
|
Some(expr) => expr.clone(),
|
|
None => quote_expr!(cx, &self.value.$name),
|
|
};
|
|
|
|
let expr = quote_expr!(cx,
|
|
serializer.$serializer_method($key_expr, $field_expr)
|
|
);
|
|
|
|
quote_arm!(cx,
|
|
$i => {
|
|
self.state += 1;
|
|
$stmt
|
|
return Ok(Some(try!($expr)));
|
|
}
|
|
)
|
|
})
|
|
.collect();
|
|
|
|
let visitor_impl_generics = builder.from_generics(generics.clone())
|
|
.add_lifetime_bound("'__a")
|
|
.lifetime_name("'__a")
|
|
.build();
|
|
|
|
let where_clause = &visitor_impl_generics.where_clause;
|
|
|
|
let visitor_generics = builder.from_generics(visitor_impl_generics.clone())
|
|
.strip_bounds()
|
|
.build();
|
|
|
|
let len = field_attrs.iter()
|
|
.filter(|field_attr| !field_attr.skip_serializing_field())
|
|
.map(|field_attr| {
|
|
match field_attr.skip_serializing_field_if() {
|
|
Some(expr) => {
|
|
quote_expr!(cx, if $expr { 0 } else { 1 })
|
|
}
|
|
None => {
|
|
quote_expr!(cx, 1)
|
|
}
|
|
}
|
|
})
|
|
.fold(quote_expr!(cx, 0), |sum, expr| quote_expr!(cx, $sum + $expr));
|
|
|
|
Ok((
|
|
quote_item!(cx,
|
|
struct Visitor $visitor_impl_generics $where_clause {
|
|
state: usize,
|
|
value: $variant_ty,
|
|
_structure_ty: ::std::marker::PhantomData<&'__a $structure_ty>,
|
|
}
|
|
).unwrap(),
|
|
|
|
quote_item!(cx,
|
|
impl $visitor_impl_generics
|
|
::serde::ser::MapVisitor
|
|
for Visitor $visitor_generics
|
|
$where_clause {
|
|
#[inline]
|
|
fn visit<S>(&mut self, serializer: &mut S) -> ::std::result::Result<Option<()>, S::Error>
|
|
where S: ::serde::ser::Serializer,
|
|
{
|
|
loop {
|
|
match self.state {
|
|
$arms
|
|
_ => { return Ok(None); }
|
|
}
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn len(&self) -> Option<usize> {
|
|
Some($len)
|
|
}
|
|
}
|
|
).unwrap(),
|
|
))
|
|
}
|