mirror of
https://github.com/pezkuwichain/serde.git
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spikefoo
1216 lines
43 KiB
Rust
1216 lines
43 KiB
Rust
// Copyright 2017 Serde Developers
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use Ctxt;
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use syn;
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use syn::MetaItem::{List, NameValue, Word};
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use syn::NestedMetaItem::{Literal, MetaItem};
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use synom::IResult;
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use std::collections::BTreeSet;
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use std::str::FromStr;
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// This module handles parsing of `#[serde(...)]` attributes. The entrypoints
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// are `attr::Container::from_ast`, `attr::Variant::from_ast`, and
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// `attr::Field::from_ast`. Each returns an instance of the corresponding
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// struct. Note that none of them return a Result. Unrecognized, malformed, or
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// duplicated attributes result in a span_err but otherwise are ignored. The
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// user will see errors simultaneously for all bad attributes in the crate
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// rather than just the first.
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pub use case::RenameRule;
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struct Attr<'c, T> {
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cx: &'c Ctxt,
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name: &'static str,
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value: Option<T>,
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}
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impl<'c, T> Attr<'c, T> {
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fn none(cx: &'c Ctxt, name: &'static str) -> Self {
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Attr {
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cx: cx,
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name: name,
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value: None,
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}
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}
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fn set(&mut self, value: T) {
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if self.value.is_some() {
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self.cx
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.error(format!("duplicate serde attribute `{}`", self.name));
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} else {
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self.value = Some(value);
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}
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}
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fn set_opt(&mut self, value: Option<T>) {
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if let Some(value) = value {
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self.set(value);
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}
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}
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fn set_if_none(&mut self, value: T) {
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if self.value.is_none() {
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self.value = Some(value);
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}
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}
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fn get(self) -> Option<T> {
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self.value
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}
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}
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struct BoolAttr<'c>(Attr<'c, ()>);
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impl<'c> BoolAttr<'c> {
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fn none(cx: &'c Ctxt, name: &'static str) -> Self {
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BoolAttr(Attr::none(cx, name))
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}
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fn set_true(&mut self) {
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self.0.set(());
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}
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fn get(&self) -> bool {
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self.0.value.is_some()
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}
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}
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#[derive(Debug)]
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pub struct Name {
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serialize: String,
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deserialize: String,
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}
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impl Name {
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/// Return the container name for the container when serializing.
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pub fn serialize_name(&self) -> String {
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self.serialize.clone()
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}
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/// Return the container name for the container when deserializing.
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pub fn deserialize_name(&self) -> String {
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self.deserialize.clone()
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}
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}
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/// Represents container (e.g. struct) attribute information
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#[derive(Debug)]
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pub struct Container {
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name: Name,
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deny_unknown_fields: bool,
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default: Default,
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rename_all: RenameRule,
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ser_bound: Option<Vec<syn::WherePredicate>>,
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de_bound: Option<Vec<syn::WherePredicate>>,
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tag: EnumTag,
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from_type: Option<syn::Ty>,
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into_type: Option<syn::Ty>,
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remote: Option<syn::Path>,
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identifier: Identifier,
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}
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/// Styles of representing an enum.
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#[derive(Debug)]
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pub enum EnumTag {
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/// The default.
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///
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/// ```json
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/// {"variant1": {"key1": "value1", "key2": "value2"}}
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/// ```
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External,
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/// `#[serde(tag = "type")]`
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///
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/// ```json
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/// {"type": "variant1", "key1": "value1", "key2": "value2"}
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/// ```
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Internal { tag: String },
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/// `#[serde(tag = "t", content = "c")]`
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///
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/// ```json
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/// {"t": "variant1", "c": {"key1": "value1", "key2": "value2"}}
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/// ```
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Adjacent { tag: String, content: String },
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/// `#[serde(untagged)]`
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///
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/// ```json
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/// {"key1": "value1", "key2": "value2"}
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/// ```
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None,
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}
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/// Whether this enum represents the fields of a struct or the variants of an
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/// enum.
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#[derive(Copy, Clone, Debug)]
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pub enum Identifier {
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/// It does not.
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No,
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/// This enum represents the fields of a struct. All of the variants must be
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/// unit variants, except possibly one which is annotated with
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/// `#[serde(other)]` and is a newtype variant.
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Field,
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/// This enum represents the variants of an enum. All of the variants must
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/// be unit variants.
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Variant,
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}
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impl Container {
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/// Extract out the `#[serde(...)]` attributes from an item.
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pub fn from_ast(cx: &Ctxt, item: &syn::DeriveInput) -> Self {
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let mut ser_name = Attr::none(cx, "rename");
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let mut de_name = Attr::none(cx, "rename");
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let mut deny_unknown_fields = BoolAttr::none(cx, "deny_unknown_fields");
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let mut default = Attr::none(cx, "default");
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let mut rename_all = Attr::none(cx, "rename_all");
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let mut ser_bound = Attr::none(cx, "bound");
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let mut de_bound = Attr::none(cx, "bound");
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let mut untagged = BoolAttr::none(cx, "untagged");
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let mut internal_tag = Attr::none(cx, "tag");
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let mut content = Attr::none(cx, "content");
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let mut from_type = Attr::none(cx, "from");
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let mut into_type = Attr::none(cx, "into");
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let mut remote = Attr::none(cx, "remote");
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let mut field_identifier = BoolAttr::none(cx, "field_identifier");
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let mut variant_identifier = BoolAttr::none(cx, "variant_identifier");
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for meta_items in item.attrs.iter().filter_map(get_serde_meta_items) {
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for meta_item in meta_items {
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match meta_item {
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// Parse `#[serde(rename = "foo")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "rename" => {
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if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
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ser_name.set(s.clone());
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de_name.set(s);
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}
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}
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// Parse `#[serde(rename(serialize = "foo", deserialize = "bar"))]`
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MetaItem(List(ref name, ref meta_items)) if name == "rename" => {
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if let Ok((ser, de)) = get_renames(cx, meta_items) {
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ser_name.set_opt(ser);
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de_name.set_opt(de);
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}
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}
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// Parse `#[serde(rename_all = "foo")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "rename_all" => {
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if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
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match RenameRule::from_str(&s) {
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Ok(rename_rule) => rename_all.set(rename_rule),
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Err(()) => {
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cx.error(format!("unknown rename rule for #[serde(rename_all \
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= {:?})]",
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s))
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}
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}
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}
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}
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// Parse `#[serde(deny_unknown_fields)]`
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MetaItem(Word(ref name)) if name == "deny_unknown_fields" => {
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deny_unknown_fields.set_true();
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}
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// Parse `#[serde(default)]`
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MetaItem(Word(ref name)) if name == "default" => {
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match item.body {
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syn::Body::Struct(syn::VariantData::Struct(_)) => {
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default.set(Default::Default);
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}
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_ => {
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cx.error(
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"#[serde(default)] can only be used on structs \
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with named fields",
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)
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}
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}
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}
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// Parse `#[serde(default = "...")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "default" => {
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if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
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match item.body {
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syn::Body::Struct(syn::VariantData::Struct(_)) => {
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default.set(Default::Path(path));
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}
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_ => {
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cx.error(
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"#[serde(default = \"...\")] can only be used \
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on structs with named fields",
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)
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}
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}
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}
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}
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// Parse `#[serde(bound = "D: Serialize")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "bound" => {
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if let Ok(where_predicates) =
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parse_lit_into_where(cx, name.as_ref(), name.as_ref(), lit) {
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ser_bound.set(where_predicates.clone());
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de_bound.set(where_predicates);
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}
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}
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// Parse `#[serde(bound(serialize = "D: Serialize", deserialize = "D: Deserialize"))]`
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MetaItem(List(ref name, ref meta_items)) if name == "bound" => {
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if let Ok((ser, de)) = get_where_predicates(cx, meta_items) {
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ser_bound.set_opt(ser);
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de_bound.set_opt(de);
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}
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}
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// Parse `#[serde(untagged)]`
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MetaItem(Word(ref name)) if name == "untagged" => {
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match item.body {
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syn::Body::Enum(_) => {
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untagged.set_true();
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}
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syn::Body::Struct(_) => {
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cx.error("#[serde(untagged)] can only be used on enums")
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}
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}
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}
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// Parse `#[serde(tag = "type")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "tag" => {
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if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
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match item.body {
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syn::Body::Enum(_) => {
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internal_tag.set(s);
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}
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syn::Body::Struct(_) => {
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cx.error("#[serde(tag = \"...\")] can only be used on enums")
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}
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}
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}
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}
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// Parse `#[serde(content = "c")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "content" => {
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if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
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match item.body {
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syn::Body::Enum(_) => {
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content.set(s);
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}
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syn::Body::Struct(_) => {
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cx.error(
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"#[serde(content = \"...\")] can only be used on \
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enums",
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)
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}
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}
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}
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}
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// Parse `#[serde(from = "Type")]
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MetaItem(NameValue(ref name, ref lit)) if name == "from" => {
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if let Ok(from_ty) = parse_lit_into_ty(cx, name.as_ref(), lit) {
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from_type.set_opt(Some(from_ty));
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}
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}
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// Parse `#[serde(into = "Type")]
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MetaItem(NameValue(ref name, ref lit)) if name == "into" => {
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if let Ok(into_ty) = parse_lit_into_ty(cx, name.as_ref(), lit) {
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into_type.set_opt(Some(into_ty));
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}
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}
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// Parse `#[serde(remote = "...")]`
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MetaItem(NameValue(ref name, ref lit)) if name == "remote" => {
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if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
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remote.set(path);
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}
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}
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// Parse `#[serde(field_identifier)]`
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MetaItem(Word(ref name)) if name == "field_identifier" => {
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field_identifier.set_true();
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}
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// Parse `#[serde(variant_identifier)]`
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MetaItem(Word(ref name)) if name == "variant_identifier" => {
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variant_identifier.set_true();
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}
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MetaItem(ref meta_item) => {
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cx.error(format!("unknown serde container attribute `{}`",
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meta_item.name()));
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}
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Literal(_) => {
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cx.error("unexpected literal in serde container attribute");
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}
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}
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}
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}
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Container {
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name: Name {
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serialize: ser_name.get().unwrap_or_else(|| item.ident.to_string()),
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deserialize: de_name.get().unwrap_or_else(|| item.ident.to_string()),
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},
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deny_unknown_fields: deny_unknown_fields.get(),
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default: default.get().unwrap_or(Default::None),
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rename_all: rename_all.get().unwrap_or(RenameRule::None),
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ser_bound: ser_bound.get(),
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de_bound: de_bound.get(),
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tag: decide_tag(cx, item, untagged, internal_tag, content),
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from_type: from_type.get(),
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into_type: into_type.get(),
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remote: remote.get(),
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identifier: decide_identifier(cx, item, field_identifier, variant_identifier),
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}
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}
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pub fn name(&self) -> &Name {
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&self.name
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}
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pub fn rename_all(&self) -> &RenameRule {
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&self.rename_all
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}
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pub fn deny_unknown_fields(&self) -> bool {
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self.deny_unknown_fields
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}
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pub fn default(&self) -> &Default {
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&self.default
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}
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pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> {
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self.ser_bound.as_ref().map(|vec| &vec[..])
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}
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pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> {
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self.de_bound.as_ref().map(|vec| &vec[..])
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}
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pub fn tag(&self) -> &EnumTag {
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&self.tag
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}
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pub fn from_type(&self) -> Option<&syn::Ty> {
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self.from_type.as_ref()
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}
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pub fn into_type(&self) -> Option<&syn::Ty> {
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self.into_type.as_ref()
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}
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pub fn remote(&self) -> Option<&syn::Path> {
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self.remote.as_ref()
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}
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pub fn identifier(&self) -> Identifier {
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self.identifier
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}
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}
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fn decide_tag(
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cx: &Ctxt,
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item: &syn::DeriveInput,
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untagged: BoolAttr,
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internal_tag: Attr<String>,
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content: Attr<String>,
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) -> EnumTag {
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match (untagged.get(), internal_tag.get(), content.get()) {
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(false, None, None) => EnumTag::External,
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(true, None, None) => EnumTag::None,
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(false, Some(tag), None) => {
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// Check that there are no tuple variants.
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if let syn::Body::Enum(ref variants) = item.body {
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for variant in variants {
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match variant.data {
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syn::VariantData::Struct(_) |
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syn::VariantData::Unit => {}
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syn::VariantData::Tuple(ref fields) => {
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if fields.len() != 1 {
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cx.error(
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"#[serde(tag = \"...\")] cannot be used with tuple \
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variants",
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);
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break;
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}
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}
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}
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}
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}
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EnumTag::Internal { tag: tag }
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}
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(true, Some(_), None) => {
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cx.error("enum cannot be both untagged and internally tagged");
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EnumTag::External // doesn't matter, will error
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}
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(false, None, Some(_)) => {
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cx.error("#[serde(tag = \"...\", content = \"...\")] must be used together",);
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EnumTag::External
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}
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(true, None, Some(_)) => {
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cx.error("untagged enum cannot have #[serde(content = \"...\")]");
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EnumTag::External
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}
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(false, Some(tag), Some(content)) => {
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EnumTag::Adjacent {
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tag: tag,
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content: content,
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}
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}
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(true, Some(_), Some(_)) => {
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cx.error("untagged enum cannot have #[serde(tag = \"...\", content = \"...\")]",);
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EnumTag::External
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}
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}
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}
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fn decide_identifier(
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cx: &Ctxt,
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item: &syn::DeriveInput,
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field_identifier: BoolAttr,
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variant_identifier: BoolAttr,
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) -> Identifier {
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match (&item.body, field_identifier.get(), variant_identifier.get()) {
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(_, false, false) => Identifier::No,
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(_, true, true) => {
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cx.error("`field_identifier` and `variant_identifier` cannot both be set",);
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Identifier::No
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}
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(&syn::Body::Struct(_), true, false) => {
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cx.error("`field_identifier` can only be used on an enum");
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Identifier::No
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}
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(&syn::Body::Struct(_), false, true) => {
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cx.error("`variant_identifier` can only be used on an enum");
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Identifier::No
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}
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(&syn::Body::Enum(_), true, false) => Identifier::Field,
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(&syn::Body::Enum(_), false, true) => Identifier::Variant,
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}
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}
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|
|
/// Represents variant attribute information
|
|
#[derive(Debug)]
|
|
pub struct Variant {
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name: Name,
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ser_renamed: bool,
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|
de_renamed: bool,
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|
rename_all: RenameRule,
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skip_deserializing: bool,
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skip_serializing: bool,
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other: bool,
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}
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|
|
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impl Variant {
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|
pub fn from_ast(cx: &Ctxt, variant: &syn::Variant) -> Self {
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let mut ser_name = Attr::none(cx, "rename");
|
|
let mut de_name = Attr::none(cx, "rename");
|
|
let mut skip_deserializing = BoolAttr::none(cx, "skip_deserializing");
|
|
let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
|
|
let mut rename_all = Attr::none(cx, "rename_all");
|
|
let mut other = BoolAttr::none(cx, "other");
|
|
|
|
for meta_items in variant.attrs.iter().filter_map(get_serde_meta_items) {
|
|
for meta_item in meta_items {
|
|
match meta_item {
|
|
// Parse `#[serde(rename = "foo")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "rename" => {
|
|
if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
|
|
ser_name.set(s.clone());
|
|
de_name.set(s);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(rename(serialize = "foo", deserialize = "bar"))]`
|
|
MetaItem(List(ref name, ref meta_items)) if name == "rename" => {
|
|
if let Ok((ser, de)) = get_renames(cx, meta_items) {
|
|
ser_name.set_opt(ser);
|
|
de_name.set_opt(de);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(rename_all = "foo")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "rename_all" => {
|
|
if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
|
|
match RenameRule::from_str(&s) {
|
|
Ok(rename_rule) => rename_all.set(rename_rule),
|
|
Err(()) => {
|
|
cx.error(format!("unknown rename rule for #[serde(rename_all \
|
|
= {:?})]",
|
|
s))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(skip_deserializing)]`
|
|
MetaItem(Word(ref name)) if name == "skip_deserializing" => {
|
|
skip_deserializing.set_true();
|
|
}
|
|
|
|
// Parse `#[serde(skip_serializing)]`
|
|
MetaItem(Word(ref name)) if name == "skip_serializing" => {
|
|
skip_serializing.set_true();
|
|
}
|
|
|
|
// Parse `#[serde(other)]`
|
|
MetaItem(Word(ref name)) if name == "other" => {
|
|
other.set_true();
|
|
}
|
|
|
|
MetaItem(ref meta_item) => {
|
|
cx.error(format!("unknown serde variant attribute `{}`", meta_item.name()));
|
|
}
|
|
|
|
Literal(_) => {
|
|
cx.error("unexpected literal in serde variant attribute");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
let ser_name = ser_name.get();
|
|
let ser_renamed = ser_name.is_some();
|
|
let de_name = de_name.get();
|
|
let de_renamed = de_name.is_some();
|
|
Variant {
|
|
name: Name {
|
|
serialize: ser_name.unwrap_or_else(|| variant.ident.to_string()),
|
|
deserialize: de_name.unwrap_or_else(|| variant.ident.to_string()),
|
|
},
|
|
ser_renamed: ser_renamed,
|
|
de_renamed: de_renamed,
|
|
rename_all: rename_all.get().unwrap_or(RenameRule::None),
|
|
skip_deserializing: skip_deserializing.get(),
|
|
skip_serializing: skip_serializing.get(),
|
|
other: other.get(),
|
|
}
|
|
}
|
|
|
|
pub fn name(&self) -> &Name {
|
|
&self.name
|
|
}
|
|
|
|
pub fn rename_by_rule(&mut self, rule: &RenameRule) {
|
|
if !self.ser_renamed {
|
|
self.name.serialize = rule.apply_to_variant(&self.name.serialize);
|
|
}
|
|
if !self.de_renamed {
|
|
self.name.deserialize = rule.apply_to_variant(&self.name.deserialize);
|
|
}
|
|
}
|
|
|
|
pub fn rename_all(&self) -> &RenameRule {
|
|
&self.rename_all
|
|
}
|
|
|
|
pub fn skip_deserializing(&self) -> bool {
|
|
self.skip_deserializing
|
|
}
|
|
|
|
pub fn skip_serializing(&self) -> bool {
|
|
self.skip_serializing
|
|
}
|
|
|
|
pub fn other(&self) -> bool {
|
|
self.other
|
|
}
|
|
}
|
|
|
|
/// Represents field attribute information
|
|
#[derive(Debug)]
|
|
pub struct Field {
|
|
name: Name,
|
|
ser_renamed: bool,
|
|
de_renamed: bool,
|
|
skip_serializing: bool,
|
|
skip_deserializing: bool,
|
|
skip_serializing_if: Option<syn::Path>,
|
|
default: Default,
|
|
serialize_with: Option<syn::Path>,
|
|
deserialize_with: Option<syn::Path>,
|
|
ser_bound: Option<Vec<syn::WherePredicate>>,
|
|
de_bound: Option<Vec<syn::WherePredicate>>,
|
|
borrowed_lifetimes: BTreeSet<syn::Lifetime>,
|
|
getter: Option<syn::Path>,
|
|
}
|
|
|
|
/// Represents the default to use for a field when deserializing.
|
|
#[derive(Debug, PartialEq)]
|
|
pub enum Default {
|
|
/// Field must always be specified because it does not have a default.
|
|
None,
|
|
/// The default is given by `std::default::Default::default()`.
|
|
Default,
|
|
/// The default is given by this function.
|
|
Path(syn::Path),
|
|
}
|
|
|
|
impl Field {
|
|
/// Extract out the `#[serde(...)]` attributes from a struct field.
|
|
pub fn from_ast(cx: &Ctxt, index: usize, field: &syn::Field) -> Self {
|
|
let mut ser_name = Attr::none(cx, "rename");
|
|
let mut de_name = Attr::none(cx, "rename");
|
|
let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
|
|
let mut skip_deserializing = BoolAttr::none(cx, "skip_deserializing");
|
|
let mut skip_serializing_if = Attr::none(cx, "skip_serializing_if");
|
|
let mut default = Attr::none(cx, "default");
|
|
let mut serialize_with = Attr::none(cx, "serialize_with");
|
|
let mut deserialize_with = Attr::none(cx, "deserialize_with");
|
|
let mut ser_bound = Attr::none(cx, "bound");
|
|
let mut de_bound = Attr::none(cx, "bound");
|
|
let mut borrowed_lifetimes = Attr::none(cx, "borrow");
|
|
let mut getter = Attr::none(cx, "getter");
|
|
|
|
let ident = match field.ident {
|
|
Some(ref ident) => ident.to_string(),
|
|
None => index.to_string(),
|
|
};
|
|
|
|
for meta_items in field.attrs.iter().filter_map(get_serde_meta_items) {
|
|
for meta_item in meta_items {
|
|
match meta_item {
|
|
// Parse `#[serde(rename = "foo")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "rename" => {
|
|
if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
|
|
ser_name.set(s.clone());
|
|
de_name.set(s);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(rename(serialize = "foo", deserialize = "bar"))]`
|
|
MetaItem(List(ref name, ref meta_items)) if name == "rename" => {
|
|
if let Ok((ser, de)) = get_renames(cx, meta_items) {
|
|
ser_name.set_opt(ser);
|
|
de_name.set_opt(de);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(default)]`
|
|
MetaItem(Word(ref name)) if name == "default" => {
|
|
default.set(Default::Default);
|
|
}
|
|
|
|
// Parse `#[serde(default = "...")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "default" => {
|
|
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
|
|
default.set(Default::Path(path));
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(skip_serializing)]`
|
|
MetaItem(Word(ref name)) if name == "skip_serializing" => {
|
|
skip_serializing.set_true();
|
|
}
|
|
|
|
// Parse `#[serde(skip_deserializing)]`
|
|
MetaItem(Word(ref name)) if name == "skip_deserializing" => {
|
|
skip_deserializing.set_true();
|
|
}
|
|
|
|
// Parse `#[serde(skip)]`
|
|
MetaItem(Word(ref name)) if name == "skip" => {
|
|
skip_serializing.set_true();
|
|
skip_deserializing.set_true();
|
|
},
|
|
|
|
// Parse `#[serde(skip_serializing_if = "...")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "skip_serializing_if" => {
|
|
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
|
|
skip_serializing_if.set(path);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(serialize_with = "...")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "serialize_with" => {
|
|
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
|
|
serialize_with.set(path);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(deserialize_with = "...")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "deserialize_with" => {
|
|
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
|
|
deserialize_with.set(path);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(with = "...")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "with" => {
|
|
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
|
|
let mut ser_path = path.clone();
|
|
ser_path.segments.push("serialize".into());
|
|
serialize_with.set(ser_path);
|
|
let mut de_path = path;
|
|
de_path.segments.push("deserialize".into());
|
|
deserialize_with.set(de_path);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(bound = "D: Serialize")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "bound" => {
|
|
if let Ok(where_predicates) =
|
|
parse_lit_into_where(cx, name.as_ref(), name.as_ref(), lit) {
|
|
ser_bound.set(where_predicates.clone());
|
|
de_bound.set(where_predicates);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(bound(serialize = "D: Serialize", deserialize = "D: Deserialize"))]`
|
|
MetaItem(List(ref name, ref meta_items)) if name == "bound" => {
|
|
if let Ok((ser, de)) = get_where_predicates(cx, meta_items) {
|
|
ser_bound.set_opt(ser);
|
|
de_bound.set_opt(de);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(borrow)]`
|
|
MetaItem(Word(ref name)) if name == "borrow" => {
|
|
if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, &field.ty) {
|
|
borrowed_lifetimes.set(borrowable);
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(borrow = "'a + 'b")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "borrow" => {
|
|
if let Ok(lifetimes) = parse_lit_into_lifetimes(cx, name.as_ref(), lit) {
|
|
if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, &field.ty) {
|
|
for lifetime in &lifetimes {
|
|
if !borrowable.contains(lifetime) {
|
|
cx.error(
|
|
format!(
|
|
"field `{}` does not have lifetime {}",
|
|
ident,
|
|
lifetime.ident
|
|
),
|
|
);
|
|
}
|
|
}
|
|
borrowed_lifetimes.set(lifetimes);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Parse `#[serde(getter = "...")]`
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "getter" => {
|
|
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
|
|
getter.set(path);
|
|
}
|
|
}
|
|
|
|
MetaItem(ref meta_item) => {
|
|
cx.error(format!("unknown serde field attribute `{}`", meta_item.name()),);
|
|
}
|
|
|
|
Literal(_) => {
|
|
cx.error("unexpected literal in serde field attribute");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Is skip_deserializing, initialize the field to Default::default()
|
|
// unless a different default is specified by `#[serde(default = "...")]`
|
|
if skip_deserializing.0.value.is_some() {
|
|
default.set_if_none(Default::Default);
|
|
}
|
|
|
|
let mut borrowed_lifetimes = borrowed_lifetimes.get().unwrap_or_default();
|
|
if !borrowed_lifetimes.is_empty() {
|
|
// Cow<str> and Cow<[u8]> never borrow by default:
|
|
//
|
|
// impl<'de, 'a, T: ?Sized> Deserialize<'de> for Cow<'a, T>
|
|
//
|
|
// A #[serde(borrow)] attribute enables borrowing that corresponds
|
|
// roughly to these impls:
|
|
//
|
|
// impl<'de: 'a, 'a> Deserialize<'de> for Cow<'a, str>
|
|
// impl<'de: 'a, 'a> Deserialize<'de> for Cow<'a, [u8]>
|
|
if is_cow(&field.ty, "str") {
|
|
let path = syn::parse_path("_serde::private::de::borrow_cow_str").unwrap();
|
|
deserialize_with.set_if_none(path);
|
|
} else if is_cow(&field.ty, "[u8]") {
|
|
let path = syn::parse_path("_serde::private::de::borrow_cow_bytes").unwrap();
|
|
deserialize_with.set_if_none(path);
|
|
}
|
|
} else if is_rptr(&field.ty, "str") || is_rptr(&field.ty, "[u8]") {
|
|
// Types &str and &[u8] are always implicitly borrowed. No need for
|
|
// a #[serde(borrow)].
|
|
borrowed_lifetimes = borrowable_lifetimes(cx, &ident, &field.ty).unwrap();
|
|
}
|
|
|
|
let ser_name = ser_name.get();
|
|
let ser_renamed = ser_name.is_some();
|
|
let de_name = de_name.get();
|
|
let de_renamed = de_name.is_some();
|
|
Field {
|
|
name: Name {
|
|
serialize: ser_name.unwrap_or_else(|| ident.clone()),
|
|
deserialize: de_name.unwrap_or(ident),
|
|
},
|
|
ser_renamed: ser_renamed,
|
|
de_renamed: de_renamed,
|
|
skip_serializing: skip_serializing.get(),
|
|
skip_deserializing: skip_deserializing.get(),
|
|
skip_serializing_if: skip_serializing_if.get(),
|
|
default: default.get().unwrap_or(Default::None),
|
|
serialize_with: serialize_with.get(),
|
|
deserialize_with: deserialize_with.get(),
|
|
ser_bound: ser_bound.get(),
|
|
de_bound: de_bound.get(),
|
|
borrowed_lifetimes: borrowed_lifetimes,
|
|
getter: getter.get(),
|
|
}
|
|
}
|
|
|
|
pub fn name(&self) -> &Name {
|
|
&self.name
|
|
}
|
|
|
|
pub fn rename_by_rule(&mut self, rule: &RenameRule) {
|
|
if !self.ser_renamed {
|
|
self.name.serialize = rule.apply_to_field(&self.name.serialize);
|
|
}
|
|
if !self.de_renamed {
|
|
self.name.deserialize = rule.apply_to_field(&self.name.deserialize);
|
|
}
|
|
}
|
|
|
|
pub fn skip_serializing(&self) -> bool {
|
|
self.skip_serializing
|
|
}
|
|
|
|
pub fn skip_deserializing(&self) -> bool {
|
|
self.skip_deserializing
|
|
}
|
|
|
|
pub fn skip_serializing_if(&self) -> Option<&syn::Path> {
|
|
self.skip_serializing_if.as_ref()
|
|
}
|
|
|
|
pub fn default(&self) -> &Default {
|
|
&self.default
|
|
}
|
|
|
|
pub fn serialize_with(&self) -> Option<&syn::Path> {
|
|
self.serialize_with.as_ref()
|
|
}
|
|
|
|
pub fn deserialize_with(&self) -> Option<&syn::Path> {
|
|
self.deserialize_with.as_ref()
|
|
}
|
|
|
|
pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> {
|
|
self.ser_bound.as_ref().map(|vec| &vec[..])
|
|
}
|
|
|
|
pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> {
|
|
self.de_bound.as_ref().map(|vec| &vec[..])
|
|
}
|
|
|
|
pub fn borrowed_lifetimes(&self) -> &BTreeSet<syn::Lifetime> {
|
|
&self.borrowed_lifetimes
|
|
}
|
|
|
|
pub fn getter(&self) -> Option<&syn::Path> {
|
|
self.getter.as_ref()
|
|
}
|
|
}
|
|
|
|
type SerAndDe<T> = (Option<T>, Option<T>);
|
|
|
|
fn get_ser_and_de<T, F>(
|
|
cx: &Ctxt,
|
|
attr_name: &'static str,
|
|
items: &[syn::NestedMetaItem],
|
|
f: F,
|
|
) -> Result<SerAndDe<T>, ()>
|
|
where
|
|
F: Fn(&Ctxt, &str, &str, &syn::Lit) -> Result<T, ()>,
|
|
{
|
|
let mut ser_item = Attr::none(cx, attr_name);
|
|
let mut de_item = Attr::none(cx, attr_name);
|
|
|
|
for item in items {
|
|
match *item {
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "serialize" => {
|
|
if let Ok(v) = f(cx, attr_name, name.as_ref(), lit) {
|
|
ser_item.set(v);
|
|
}
|
|
}
|
|
|
|
MetaItem(NameValue(ref name, ref lit)) if name == "deserialize" => {
|
|
if let Ok(v) = f(cx, attr_name, name.as_ref(), lit) {
|
|
de_item.set(v);
|
|
}
|
|
}
|
|
|
|
_ => {
|
|
cx.error(
|
|
format!(
|
|
"malformed {0} attribute, expected `{0}(serialize = ..., \
|
|
deserialize = ...)`",
|
|
attr_name
|
|
),
|
|
);
|
|
return Err(());
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok((ser_item.get(), de_item.get()))
|
|
}
|
|
|
|
fn get_renames(cx: &Ctxt, items: &[syn::NestedMetaItem]) -> Result<SerAndDe<String>, ()> {
|
|
get_ser_and_de(cx, "rename", items, get_string_from_lit)
|
|
}
|
|
|
|
fn get_where_predicates(
|
|
cx: &Ctxt,
|
|
items: &[syn::NestedMetaItem],
|
|
) -> Result<SerAndDe<Vec<syn::WherePredicate>>, ()> {
|
|
get_ser_and_de(cx, "bound", items, parse_lit_into_where)
|
|
}
|
|
|
|
pub fn get_serde_meta_items(attr: &syn::Attribute) -> Option<Vec<syn::NestedMetaItem>> {
|
|
match attr.value {
|
|
List(ref name, ref items) if name == "serde" => Some(items.iter().cloned().collect()),
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
fn get_string_from_lit(
|
|
cx: &Ctxt,
|
|
attr_name: &str,
|
|
meta_item_name: &str,
|
|
lit: &syn::Lit,
|
|
) -> Result<String, ()> {
|
|
if let syn::Lit::Str(ref s, _) = *lit {
|
|
Ok(s.clone())
|
|
} else {
|
|
cx.error(
|
|
format!(
|
|
"expected serde {} attribute to be a string: `{} = \"...\"`",
|
|
attr_name,
|
|
meta_item_name
|
|
),
|
|
);
|
|
Err(())
|
|
}
|
|
}
|
|
|
|
fn parse_lit_into_path(cx: &Ctxt, attr_name: &str, lit: &syn::Lit) -> Result<syn::Path, ()> {
|
|
let string = try!(get_string_from_lit(cx, attr_name, attr_name, lit));
|
|
syn::parse_path(&string).map_err(|err| cx.error(err))
|
|
}
|
|
|
|
fn parse_lit_into_where(
|
|
cx: &Ctxt,
|
|
attr_name: &str,
|
|
meta_item_name: &str,
|
|
lit: &syn::Lit,
|
|
) -> Result<Vec<syn::WherePredicate>, ()> {
|
|
let string = try!(get_string_from_lit(cx, attr_name, meta_item_name, lit));
|
|
if string.is_empty() {
|
|
return Ok(Vec::new());
|
|
}
|
|
|
|
let where_string = format!("where {}", string);
|
|
|
|
syn::parse_where_clause(&where_string)
|
|
.map(|wh| wh.predicates)
|
|
.map_err(|err| cx.error(err))
|
|
}
|
|
|
|
fn parse_lit_into_ty(cx: &Ctxt, attr_name: &str, lit: &syn::Lit) -> Result<syn::Ty, ()> {
|
|
let string = try!(get_string_from_lit(cx, attr_name, attr_name, lit));
|
|
|
|
syn::parse_type(&string).map_err(
|
|
|_| {
|
|
cx.error(format!("failed to parse type: {} = {:?}", attr_name, string),)
|
|
},
|
|
)
|
|
}
|
|
|
|
// Parses a string literal like "'a + 'b + 'c" containing a nonempty list of
|
|
// lifetimes separated by `+`.
|
|
fn parse_lit_into_lifetimes(
|
|
cx: &Ctxt,
|
|
attr_name: &str,
|
|
lit: &syn::Lit,
|
|
) -> Result<BTreeSet<syn::Lifetime>, ()> {
|
|
let string = try!(get_string_from_lit(cx, attr_name, attr_name, lit));
|
|
if string.is_empty() {
|
|
cx.error("at least one lifetime must be borrowed");
|
|
return Err(());
|
|
}
|
|
|
|
named!(lifetimes -> Vec<syn::Lifetime>,
|
|
separated_nonempty_list!(punct!("+"), syn::parse::lifetime)
|
|
);
|
|
|
|
if let IResult::Done(rest, o) = lifetimes(&string) {
|
|
if rest.trim().is_empty() {
|
|
let mut set = BTreeSet::new();
|
|
for lifetime in o {
|
|
if !set.insert(lifetime.clone()) {
|
|
cx.error(format!("duplicate borrowed lifetime `{}`", lifetime.ident));
|
|
}
|
|
}
|
|
return Ok(set);
|
|
}
|
|
}
|
|
Err(cx.error(format!("failed to parse borrowed lifetimes: {:?}", string)),)
|
|
}
|
|
|
|
// Whether the type looks like it might be `std::borrow::Cow<T>` where elem="T".
|
|
// This can have false negatives and false positives.
|
|
//
|
|
// False negative:
|
|
//
|
|
// use std::borrow::Cow as Pig;
|
|
//
|
|
// #[derive(Deserialize)]
|
|
// struct S<'a> {
|
|
// #[serde(borrow)]
|
|
// pig: Pig<'a, str>,
|
|
// }
|
|
//
|
|
// False positive:
|
|
//
|
|
// type str = [i16];
|
|
//
|
|
// #[derive(Deserialize)]
|
|
// struct S<'a> {
|
|
// #[serde(borrow)]
|
|
// cow: Cow<'a, str>,
|
|
// }
|
|
fn is_cow(ty: &syn::Ty, elem: &str) -> bool {
|
|
let path = match *ty {
|
|
syn::Ty::Path(None, ref path) => path,
|
|
_ => {
|
|
return false;
|
|
}
|
|
};
|
|
let seg = match path.segments.last() {
|
|
Some(seg) => seg,
|
|
None => {
|
|
return false;
|
|
}
|
|
};
|
|
let params = match seg.parameters {
|
|
syn::PathParameters::AngleBracketed(ref params) => params,
|
|
_ => {
|
|
return false;
|
|
}
|
|
};
|
|
seg.ident == "Cow" && params.lifetimes.len() == 1 &&
|
|
params.types == vec![syn::parse_type(elem).unwrap()] && params.bindings.is_empty()
|
|
}
|
|
|
|
// Whether the type looks like it might be `&T` where elem="T". This can have
|
|
// false negatives and false positives.
|
|
//
|
|
// False negative:
|
|
//
|
|
// type Yarn = str;
|
|
//
|
|
// #[derive(Deserialize)]
|
|
// struct S<'a> {
|
|
// r: &'a Yarn,
|
|
// }
|
|
//
|
|
// False positive:
|
|
//
|
|
// type str = [i16];
|
|
//
|
|
// #[derive(Deserialize)]
|
|
// struct S<'a> {
|
|
// r: &'a str,
|
|
// }
|
|
fn is_rptr(ty: &syn::Ty, elem: &str) -> bool {
|
|
match *ty {
|
|
syn::Ty::Rptr(Some(_), ref mut_ty) => {
|
|
mut_ty.mutability == syn::Mutability::Immutable &&
|
|
mut_ty.ty == syn::parse_type(elem).unwrap()
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
// All lifetimes that this type could borrow from a Deserializer.
|
|
//
|
|
// For example a type `S<'a, 'b>` could borrow `'a` and `'b`. On the other hand
|
|
// a type `for<'a> fn(&'a str)` could not borrow `'a` from the Deserializer.
|
|
//
|
|
// This is used when there is an explicit or implicit `#[serde(borrow)]`
|
|
// attribute on the field so there must be at least one borrowable lifetime.
|
|
fn borrowable_lifetimes(
|
|
cx: &Ctxt,
|
|
name: &str,
|
|
ty: &syn::Ty,
|
|
) -> Result<BTreeSet<syn::Lifetime>, ()> {
|
|
let mut lifetimes = BTreeSet::new();
|
|
collect_lifetimes(ty, &mut lifetimes);
|
|
if lifetimes.is_empty() {
|
|
Err(cx.error(format!("field `{}` has no lifetimes to borrow", name)),)
|
|
} else {
|
|
Ok(lifetimes)
|
|
}
|
|
}
|
|
|
|
fn collect_lifetimes(ty: &syn::Ty, out: &mut BTreeSet<syn::Lifetime>) {
|
|
match *ty {
|
|
syn::Ty::Slice(ref elem) |
|
|
syn::Ty::Array(ref elem, _) |
|
|
syn::Ty::Paren(ref elem) => {
|
|
collect_lifetimes(elem, out);
|
|
}
|
|
syn::Ty::Ptr(ref elem) => {
|
|
collect_lifetimes(&elem.ty, out);
|
|
}
|
|
syn::Ty::Rptr(ref lifetime, ref elem) => {
|
|
out.extend(lifetime.iter().cloned());
|
|
collect_lifetimes(&elem.ty, out);
|
|
}
|
|
syn::Ty::Tup(ref elems) => {
|
|
for elem in elems {
|
|
collect_lifetimes(elem, out);
|
|
}
|
|
}
|
|
syn::Ty::Path(ref qself, ref path) => {
|
|
if let Some(ref qself) = *qself {
|
|
collect_lifetimes(&qself.ty, out);
|
|
}
|
|
for seg in &path.segments {
|
|
if let syn::PathParameters::AngleBracketed(ref params) = seg.parameters {
|
|
out.extend(params.lifetimes.iter().cloned());
|
|
for ty in ¶ms.types {
|
|
collect_lifetimes(ty, out);
|
|
}
|
|
for binding in ¶ms.bindings {
|
|
collect_lifetimes(&binding.ty, out);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
syn::Ty::BareFn(_) |
|
|
syn::Ty::Never |
|
|
syn::Ty::TraitObject(_) |
|
|
syn::Ty::ImplTrait(_) |
|
|
syn::Ty::Infer |
|
|
syn::Ty::Mac(_) => {}
|
|
}
|
|
}
|