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Derive for borrowed fields

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This commit is contained in:
David Tolnay 2017-04-02 21:42:07 -07:00
parent 8c3e72f2c8
commit fb48111e46
No known key found for this signature in database
GPG Key ID: F9BA143B95FF6D82
12 changed files with 505 additions and 103 deletions
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8
serde/src/de/impls.rs
View File

@ -328,9 +328,9 @@ impl<'a> Visitor<'a> for StrVisitor {
}
}
impl<'a> Deserialize<'a> for &'a str {
impl<'de: 'a, 'a> Deserialize<'de> for &'a str {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'a>
where D: Deserializer<'de>
{
deserializer.deserialize_str(StrVisitor)
}
@ -360,9 +360,9 @@ impl<'a> Visitor<'a> for BytesVisitor {
}
}
impl<'a> Deserialize<'a> for &'a [u8] {
impl<'de: 'a, 'a> Deserialize<'de> for &'a [u8] {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'a>
where D: Deserializer<'de>
{
deserializer.deserialize_bytes(BytesVisitor)
}

132
serde/src/de/private.rs
View File

@ -1,7 +1,24 @@
#[cfg(any(feature = "std", feature = "collections"))]
use core::{fmt, str};
use core::marker::PhantomData;
#[cfg(feature = "collections")]
use collections::borrow::ToOwned;
#[cfg(feature = "std")]
use std::borrow::Cow;
#[cfg(all(feature = "collections", not(feature = "std")))]
use collections::borrow::Cow;
#[cfg(all(feature = "collections", not(feature = "std")))]
use collections::{String, Vec};
use de::{Deserialize, Deserializer, Error, Visitor};
#[cfg(any(feature = "std", feature = "collections"))]
use de::Unexpected;
#[cfg(any(feature = "std", feature = "collections"))]
pub use de::content::{Content, ContentRefDeserializer, ContentDeserializer, TaggedContentVisitor,
TagOrContentField, TagOrContentFieldVisitor, InternallyTaggedUnitVisitor,
@ -42,3 +59,118 @@ pub fn missing_field<'de, V, E>(field: &'static str) -> Result<V, E>
let deserializer = MissingFieldDeserializer(field, PhantomData);
Deserialize::deserialize(deserializer)
}
#[cfg(any(feature = "std", feature = "collections"))]
pub fn borrow_cow_str<'de, D>(deserializer: D) -> Result<Cow<'de, str>, D::Error>
where D: Deserializer<'de>
{
struct CowStrVisitor;
impl<'a> Visitor<'a> for CowStrVisitor {
type Value = Cow<'a, str>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a string")
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Owned(v.to_owned()))
}
fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Borrowed(v))
}
fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Owned(v))
}
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
where E: Error
{
match str::from_utf8(v) {
Ok(s) => Ok(Cow::Owned(s.to_owned())),
Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
}
}
fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E>
where E: Error
{
match str::from_utf8(v) {
Ok(s) => Ok(Cow::Borrowed(s)),
Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
}
}
fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
where E: Error
{
match String::from_utf8(v) {
Ok(s) => Ok(Cow::Owned(s)),
Err(e) => Err(Error::invalid_value(Unexpected::Bytes(&e.into_bytes()), &self)),
}
}
}
deserializer.deserialize_str(CowStrVisitor)
}
#[cfg(any(feature = "std", feature = "collections"))]
pub fn borrow_cow_bytes<'de, D>(deserializer: D) -> Result<Cow<'de, [u8]>, D::Error>
where D: Deserializer<'de>
{
struct CowBytesVisitor;
impl<'a> Visitor<'a> for CowBytesVisitor {
type Value = Cow<'a, [u8]>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a byte array")
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Owned(v.as_bytes().to_vec()))
}
fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Borrowed(v.as_bytes()))
}
fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Owned(v.into_bytes()))
}
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Owned(v.to_vec()))
}
fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Borrowed(v))
}
fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
where E: Error
{
Ok(Cow::Owned(v))
}
}
deserializer.deserialize_str(CowBytesVisitor)
}

3
serde_codegen_internals/Cargo.toml
View File

@ -12,7 +12,8 @@ readme = "../README.md"
include = ["Cargo.toml", "src/**/*.rs", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
[dependencies]
syn = { version = "0.11", default-features = false, features = ["parsing"] }
syn = { version = "0.11.10", default-features = false, features = ["parsing"] }
synom = "0.11"
[badges]
travis-ci = { repository = "serde-rs/serde" }

225
serde_codegen_internals/src/attr.rs
View File

@ -2,6 +2,8 @@ use Ctxt;
use syn;
use syn::MetaItem::{List, NameValue, Word};
use syn::NestedMetaItem::{Literal, MetaItem};
use synom::IResult;
use std::collections::BTreeSet;
use std::str::FromStr;
// This module handles parsing of `#[serde(...)]` attributes. The entrypoints
@ -528,6 +530,7 @@ pub struct Field {
deserialize_with: Option<syn::Path>,
ser_bound: Option<Vec<syn::WherePredicate>>,
de_bound: Option<Vec<syn::WherePredicate>>,
borrowed_lifetimes: BTreeSet<syn::Lifetime>,
}
/// Represents the default to use for a field when deserializing.
@ -554,6 +557,7 @@ impl Field {
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 ident = match field.ident {
Some(ref ident) => ident.to_string(),
@ -651,6 +655,27 @@ impl Field {
}
}
// 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);
}
}
}
MetaItem(ref meta_item) => {
cx.error(format!("unknown serde field attribute `{}`", meta_item.name()));
}
@ -668,6 +693,30 @@ impl Field {
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::de::private::borrow_cow_str").unwrap();
deserialize_with.set_if_none(path);
} else if is_cow(&field.ty, "[u8]") {
let path = syn::parse_path("_serde::de::private::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();
@ -687,6 +736,7 @@ impl Field {
deserialize_with: deserialize_with.get(),
ser_bound: ser_bound.get(),
de_bound: de_bound.get(),
borrowed_lifetimes: borrowed_lifetimes,
}
}
@ -734,6 +784,10 @@ impl Field {
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
}
}
type SerAndDe<T> = (Option<T>, Option<T>);
@ -836,3 +890,174 @@ fn parse_lit_into_ty(cx: &Ctxt,
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 &params.types {
collect_lifetimes(ty, out);
}
for binding in &params.bindings {
collect_lifetimes(&binding.ty, out);
}
}
}
}
syn::Ty::BareFn(_) |
syn::Ty::Never |
syn::Ty::TraitObject(_) |
syn::Ty::ImplTrait(_) |
syn::Ty::Infer |
syn::Ty::Mac(_) => {}
}
}

2
serde_codegen_internals/src/lib.rs
View File

@ -1,4 +1,6 @@
extern crate syn;
#[macro_use]
extern crate synom;
pub mod ast;
pub mod attr;

179
serde_derive/src/de.rs
View File

@ -6,20 +6,20 @@ use fragment::{Fragment, Expr, Stmts, Match};
use internals::ast::{Body, Field, Item, Style, Variant};
use internals::{self, attr};
use std::collections::BTreeSet;
pub fn expand_derive_deserialize(item: &syn::DeriveInput) -> Result<Tokens, String> {
let item = {
let ctxt = internals::Ctxt::new();
let item = Item::from_ast(&ctxt, item);
check_no_str(&ctxt, &item);
try!(ctxt.check());
item
};
let ctxt = internals::Ctxt::new();
let item = Item::from_ast(&ctxt, item);
try!(ctxt.check());
let ident = &item.ident;
let generics = build_generics(&item);
let (de_impl_generics, _, ty_generics, where_clause) = split_with_de_lifetime(&generics);
let borrowed = borrowed_lifetimes(&item);
let params = Parameters { generics: generics, borrowed: borrowed };
let (de_impl_generics, _, ty_generics, where_clause) = split_with_de_lifetime(&params);
let dummy_const = Ident::new(format!("_IMPL_DESERIALIZE_FOR_{}", ident));
let body = Stmts(deserialize_body(&item, &generics));
let body = Stmts(deserialize_body(&item, &params));
Ok(quote! {
#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
@ -37,6 +37,11 @@ pub fn expand_derive_deserialize(item: &syn::DeriveInput) -> Result<Tokens, Stri
})
}
struct Parameters {
generics: syn::Generics,
borrowed: BTreeSet<syn::Lifetime>,
}
// All the generics in the input, plus a bound `T: Deserialize` for each generic
// field type that will be deserialized by us, plus a bound `T: Default` for
// each generic field type that will be set to a default value.
@ -84,13 +89,27 @@ fn requires_default(attrs: &attr::Field) -> bool {
attrs.default() == &attr::Default::Default
}
fn deserialize_body(item: &Item, generics: &syn::Generics) -> Fragment {
// The union of lifetimes borrowed by each field of the item.
//
// These turn into bounds on the `'de` lifetime of the Deserialize impl. If
// lifetimes `'a` and `'b` are borrowed but `'c` is not, the impl is:
//
// impl<'de: 'a + 'b, 'a, 'b, 'c> Deserialize<'de> for S<'a, 'b, 'c>
fn borrowed_lifetimes(item: &Item) -> BTreeSet<syn::Lifetime> {
let mut lifetimes = BTreeSet::new();
for field in item.body.all_fields() {
lifetimes.extend(field.attrs.borrowed_lifetimes().iter().cloned());
}
lifetimes
}
fn deserialize_body(item: &Item, params: &Parameters) -> Fragment {
if let Some(from_type) = item.attrs.from_type() {
deserialize_from(from_type)
} else {
match item.body {
Body::Enum(ref variants) => {
deserialize_item_enum(&item.ident, generics, variants, &item.attrs)
deserialize_item_enum(&item.ident, params, variants, &item.attrs)
}
Body::Struct(Style::Struct, ref fields) => {
if fields.iter().any(|field| field.ident.is_none()) {
@ -98,7 +117,7 @@ fn deserialize_body(item: &Item, generics: &syn::Generics) -> Fragment {
}
deserialize_struct(&item.ident,
None,
generics,
params,
fields,
&item.attrs,
None)
@ -110,7 +129,7 @@ fn deserialize_body(item: &Item, generics: &syn::Generics) -> Fragment {
}
deserialize_tuple(&item.ident,
None,
generics,
params,
fields,
&item.attrs,
None)
@ -164,12 +183,12 @@ fn deserialize_unit_struct(ident: &syn::Ident, item_attrs: &attr::Item) -> Fragm
fn deserialize_tuple(ident: &syn::Ident,
variant_ident: Option<&syn::Ident>,
generics: &syn::Generics,
params: &Parameters,
fields: &[Field],
item_attrs: &attr::Item,
deserializer: Option<Tokens>)
-> Fragment {
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(generics);
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(params);
let is_enum = variant_ident.is_some();
let type_path = match variant_ident {
@ -184,12 +203,12 @@ fn deserialize_tuple(ident: &syn::Ident,
let nfields = fields.len();
let visit_newtype_struct = if !is_enum && nfields == 1 {
Some(deserialize_newtype_struct(ident, &type_path, generics, &fields[0]))
Some(deserialize_newtype_struct(ident, &type_path, params, &fields[0]))
} else {
None
};
let visit_seq = Stmts(deserialize_seq(ident, &type_path, generics, fields, false, item_attrs));
let visit_seq = Stmts(deserialize_seq(ident, &type_path, params, fields, false, item_attrs));
let visitor_expr = quote! {
__Visitor {
@ -245,7 +264,7 @@ fn deserialize_tuple(ident: &syn::Ident,
fn deserialize_seq(ident: &syn::Ident,
type_path: &Tokens,
generics: &syn::Generics,
params: &Parameters,
fields: &[Field],
is_struct: bool,
item_attrs: &attr::Item)
@ -273,7 +292,7 @@ fn deserialize_seq(ident: &syn::Ident,
}
Some(path) => {
let (wrapper, wrapper_ty) = wrap_deserialize_with(
ident, generics, field.ty, path);
ident, params, field.ty, path);
quote!({
#wrapper
_serde::export::Option::map(
@ -314,7 +333,7 @@ fn deserialize_seq(ident: &syn::Ident,
fn deserialize_newtype_struct(ident: &syn::Ident,
type_path: &Tokens,
generics: &syn::Generics,
params: &Parameters,
field: &Field)
-> Tokens {
let value = match field.attrs.deserialize_with() {
@ -326,7 +345,7 @@ fn deserialize_newtype_struct(ident: &syn::Ident,
}
Some(path) => {
let (wrapper, wrapper_ty) =
wrap_deserialize_with(ident, generics, field.ty, path);
wrap_deserialize_with(ident, params, field.ty, path);
quote!({
#wrapper
try!(<#wrapper_ty as _serde::Deserialize>::deserialize(__e)).value
@ -345,7 +364,7 @@ fn deserialize_newtype_struct(ident: &syn::Ident,
fn deserialize_struct(ident: &syn::Ident,
variant_ident: Option<&syn::Ident>,
generics: &syn::Generics,
params: &Parameters,
fields: &[Field],
item_attrs: &attr::Item,
deserializer: Option<Tokens>)
@ -353,7 +372,7 @@ fn deserialize_struct(ident: &syn::Ident,
let is_enum = variant_ident.is_some();
let is_untagged = deserializer.is_some();
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(generics);
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(params);
let type_path = match variant_ident {
Some(variant_ident) => quote!(#ident::#variant_ident),
@ -364,10 +383,10 @@ fn deserialize_struct(ident: &syn::Ident,
None => format!("struct {}", ident),
};
let visit_seq = Stmts(deserialize_seq(ident, &type_path, generics, fields, true, item_attrs));
let visit_seq = Stmts(deserialize_seq(ident, &type_path, params, fields, true, item_attrs));
let (field_visitor, fields_stmt, visit_map) =
deserialize_struct_visitor(ident, type_path, generics, fields, item_attrs);
deserialize_struct_visitor(ident, type_path, params, fields, item_attrs);
let field_visitor = Stmts(field_visitor);
let fields_stmt = Stmts(fields_stmt);
let visit_map = Stmts(visit_map);
@ -446,41 +465,41 @@ fn deserialize_struct(ident: &syn::Ident,
}
fn deserialize_item_enum(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variants: &[Variant],
item_attrs: &attr::Item)
-> Fragment {
match *item_attrs.tag() {
attr::EnumTag::External => {
deserialize_externally_tagged_enum(ident, generics, variants, item_attrs)
deserialize_externally_tagged_enum(ident, params, variants, item_attrs)
}
attr::EnumTag::Internal { ref tag } => {
deserialize_internally_tagged_enum(ident,
generics,
params,
variants,
item_attrs,
tag)
}
attr::EnumTag::Adjacent { ref tag, ref content } => {
deserialize_adjacently_tagged_enum(ident,
generics,
params,
variants,
item_attrs,
tag,
content)
}
attr::EnumTag::None => {
deserialize_untagged_enum(ident, generics, variants, item_attrs)
deserialize_untagged_enum(ident, params, variants, item_attrs)
}
}
}
fn deserialize_externally_tagged_enum(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variants: &[Variant],
item_attrs: &attr::Item)
-> Fragment {
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(generics);
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(params);
let type_name = item_attrs.name().deserialize_name();
@ -509,7 +528,7 @@ fn deserialize_externally_tagged_enum(ident: &syn::Ident,
let variant_name = field_i(i);
let block = Match(deserialize_externally_tagged_variant(ident,
generics,
params,
variant,
item_attrs));
@ -571,7 +590,7 @@ fn deserialize_externally_tagged_enum(ident: &syn::Ident,
}
fn deserialize_internally_tagged_enum(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variants: &[Variant],
item_attrs: &attr::Item,
tag: &str)
@ -600,7 +619,7 @@ fn deserialize_internally_tagged_enum(ident: &syn::Ident,
let block = Match(deserialize_internally_tagged_variant(
ident,
generics,
params,
variant,
item_attrs,
quote!(_serde::de::private::ContentDeserializer::<__D::Error>::new(__tagged.content)),
@ -627,13 +646,13 @@ fn deserialize_internally_tagged_enum(ident: &syn::Ident,
}
fn deserialize_adjacently_tagged_enum(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variants: &[Variant],
item_attrs: &attr::Item,
tag: &str,
content: &str)
-> Fragment {
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(generics);
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(params);
let variant_names_idents: Vec<_> = variants.iter()
.enumerate()
@ -658,7 +677,7 @@ fn deserialize_adjacently_tagged_enum(ident: &syn::Ident,
let block = Match(deserialize_untagged_variant(
ident,
generics,
params,
variant,
item_attrs,
quote!(__deserializer),
@ -866,7 +885,7 @@ fn deserialize_adjacently_tagged_enum(ident: &syn::Ident,
}
fn deserialize_untagged_enum(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variants: &[Variant],
item_attrs: &attr::Item)
-> Fragment {
@ -875,7 +894,7 @@ fn deserialize_untagged_enum(ident: &syn::Ident,
.map(|variant| {
Expr(deserialize_untagged_variant(
ident,
generics,
params,
variant,
item_attrs,
quote!(_serde::de::private::ContentRefDeserializer::<__D::Error>::new(&__content)),
@ -904,7 +923,7 @@ fn deserialize_untagged_enum(ident: &syn::Ident,
}
fn deserialize_externally_tagged_variant(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variant: &Variant,
item_attrs: &attr::Item)
-> Fragment {
@ -920,13 +939,13 @@ fn deserialize_externally_tagged_variant(ident: &syn::Ident,
Style::Newtype => {
deserialize_externally_tagged_newtype_variant(ident,
variant_ident,
generics,
params,
&variant.fields[0])
}
Style::Tuple => {
deserialize_tuple(ident,
Some(variant_ident),
generics,
params,
&variant.fields,
item_attrs,
None)
@ -934,7 +953,7 @@ fn deserialize_externally_tagged_variant(ident: &syn::Ident,
Style::Struct => {
deserialize_struct(ident,
Some(variant_ident),
generics,
params,
&variant.fields,
item_attrs,
None)
@ -943,7 +962,7 @@ fn deserialize_externally_tagged_variant(ident: &syn::Ident,
}
fn deserialize_internally_tagged_variant(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variant: &Variant,
item_attrs: &attr::Item,
deserializer: Tokens)
@ -961,7 +980,7 @@ fn deserialize_internally_tagged_variant(ident: &syn::Ident,
}
Style::Newtype | Style::Struct => {
deserialize_untagged_variant(ident,
generics,
params,
variant,
item_attrs,
deserializer)
@ -971,7 +990,7 @@ fn deserialize_internally_tagged_variant(ident: &syn::Ident,
}
fn deserialize_untagged_variant(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
variant: &Variant,
item_attrs: &attr::Item,
deserializer: Tokens)
@ -994,14 +1013,14 @@ fn deserialize_untagged_variant(ident: &syn::Ident,
Style::Newtype => {
deserialize_untagged_newtype_variant(ident,
variant_ident,
generics,
params,
&variant.fields[0],
deserializer)
}
Style::Tuple => {
deserialize_tuple(ident,
Some(variant_ident),
generics,
params,
&variant.fields,
item_attrs,
Some(deserializer))
@ -1009,7 +1028,7 @@ fn deserialize_untagged_variant(ident: &syn::Ident,
Style::Struct => {
deserialize_struct(ident,
Some(variant_ident),
generics,
params,
&variant.fields,
item_attrs,
Some(deserializer))
@ -1019,7 +1038,7 @@ fn deserialize_untagged_variant(ident: &syn::Ident,
fn deserialize_externally_tagged_newtype_variant(ident: &syn::Ident,
variant_ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
field: &Field)
-> Fragment {
match field.attrs.deserialize_with() {
@ -1033,7 +1052,7 @@ fn deserialize_externally_tagged_newtype_variant(ident: &syn::Ident,
}
Some(path) => {
let (wrapper, wrapper_ty) =
wrap_deserialize_with(ident, generics, field.ty, path);
wrap_deserialize_with(ident, params, field.ty, path);
quote_block! {
#wrapper
_serde::export::Result::map(
@ -1046,7 +1065,7 @@ fn deserialize_externally_tagged_newtype_variant(ident: &syn::Ident,
fn deserialize_untagged_newtype_variant(ident: &syn::Ident,
variant_ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
field: &Field,
deserializer: Tokens)
-> Fragment {
@ -1061,7 +1080,7 @@ fn deserialize_untagged_newtype_variant(ident: &syn::Ident,
}
Some(path) => {
let (wrapper, wrapper_ty) =
wrap_deserialize_with(ident, generics, field.ty, path);
wrap_deserialize_with(ident, params, field.ty, path);
quote_block! {
#wrapper
_serde::export::Result::map(
@ -1186,7 +1205,7 @@ fn deserialize_field_visitor(fields: Vec<(String, Ident)>,
fn deserialize_struct_visitor(ident: &syn::Ident,
struct_path: Tokens,
generics: &syn::Generics,
params: &Parameters,
fields: &[Field],
item_attrs: &attr::Item)
-> (Fragment, Fragment, Fragment) {
@ -1205,14 +1224,14 @@ fn deserialize_struct_visitor(ident: &syn::Ident,
let field_visitor = deserialize_field_visitor(field_names_idents, item_attrs, false);
let visit_map = deserialize_map(ident, struct_path, generics, fields, item_attrs);
let visit_map = deserialize_map(ident, struct_path, params, fields, item_attrs);
(field_visitor, fields_stmt, visit_map)
}
fn deserialize_map(ident: &syn::Ident,
struct_path: Tokens,
generics: &syn::Generics,
params: &Parameters,
fields: &[Field],
item_attrs: &attr::Item)
-> Fragment {
@ -1247,7 +1266,7 @@ fn deserialize_map(ident: &syn::Ident,
}
Some(path) => {
let (wrapper, wrapper_ty) = wrap_deserialize_with(
ident, generics, field.ty, path);
ident, params, field.ty, path);
quote!({
#wrapper
try!(_serde::de::MapVisitor::visit_value::<#wrapper_ty>(&mut __visitor)).value
@ -1355,11 +1374,11 @@ fn field_i(i: usize) -> Ident {
/// This function wraps the expression in `#[serde(deserialize_with="...")]` in
/// a trait to prevent it from accessing the internal `Deserialize` state.
fn wrap_deserialize_with(ident: &syn::Ident,
generics: &syn::Generics,
params: &Parameters,
field_ty: &syn::Ty,
deserialize_with: &syn::Path)
-> (Tokens, Tokens) {
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(generics);
let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = split_with_de_lifetime(params);
let wrapper = quote! {
struct __DeserializeWith #de_impl_generics #where_clause {
@ -1420,34 +1439,16 @@ fn expr_is_missing(field: &Field, item_attrs: &attr::Item) -> Fragment {
}
}
fn check_no_str(cx: &internals::Ctxt, item: &Item) {
let fail = || {
cx.error("Serde does not support deserializing fields of type &str; consider using \
String instead");
};
for field in item.body.all_fields() {
if field.attrs.skip_deserializing() || field.attrs.deserialize_with().is_some() {
continue;
}
if let syn::Ty::Rptr(_, ref inner) = *field.ty {
if let syn::Ty::Path(_, ref path) = inner.ty {
if path.segments.len() == 1 && path.segments[0].ident == "str" {
fail();
return;
}
}
}
}
}
struct DeImplGenerics<'a>(&'a syn::Generics);
struct DeImplGenerics<'a>(&'a Parameters);
impl<'a> ToTokens for DeImplGenerics<'a> {
fn to_tokens(&self, tokens: &mut Tokens) {
let mut generics = self.0.clone();
generics.lifetimes.insert(0, syn::LifetimeDef::new("'de"));
let mut generics = self.0.generics.clone();
generics.lifetimes.insert(0, syn::LifetimeDef {
attrs: Vec::new(),
lifetime: syn::Lifetime::new("'de"),
bounds: self.0.borrowed.iter().cloned().collect(),
});
let (impl_generics, _, _) = generics.split_for_impl();
impl_generics.to_tokens(tokens);
}
@ -1464,9 +1465,9 @@ impl<'a> ToTokens for DeTyGenerics<'a> {
}
}
fn split_with_de_lifetime(generics: &syn::Generics) -> (DeImplGenerics, DeTyGenerics, syn::TyGenerics, &syn::WhereClause) {
let de_impl_generics = DeImplGenerics(generics);
let de_ty_generics = DeTyGenerics(generics);
let (_, ty_generics, where_clause) = generics.split_for_impl();
fn split_with_de_lifetime(params: &Parameters) -> (DeImplGenerics, DeTyGenerics, syn::TyGenerics, &syn::WhereClause) {
let de_impl_generics = DeImplGenerics(&params);
let de_ty_generics = DeTyGenerics(&params.generics);
let (_, ty_generics, where_clause) = params.generics.split_for_impl();
(de_impl_generics, de_ty_generics, ty_generics, where_clause)
}

10
test_suite/tests/compile-fail/borrow/bad_lifetimes.rs Normal file
View File

@ -0,0 +1,10 @@
#[macro_use]
extern crate serde_derive;
#[derive(Deserialize)] //~ ERROR: proc-macro derive panicked
struct Test<'a> {
#[serde(borrow = "zzz")] //~^^ HELP: failed to parse borrowed lifetimes: "zzz"
s: &'a str,
}
fn main() {}

10
test_suite/tests/compile-fail/borrow/duplicate_lifetime.rs Normal file
View File

@ -0,0 +1,10 @@
#[macro_use]
extern crate serde_derive;
#[derive(Deserialize)] //~ ERROR: proc-macro derive panicked
struct Test<'a> {
#[serde(borrow = "'a + 'a")] //~^^ HELP: duplicate borrowed lifetime `'a`
s: &'a str,
}
fn main() {}

10
test_suite/tests/compile-fail/borrow/empty_lifetimes.rs Normal file
View File

@ -0,0 +1,10 @@
#[macro_use]
extern crate serde_derive;
#[derive(Deserialize)] //~ ERROR: proc-macro derive panicked
struct Test<'a> {
#[serde(borrow = "")] //~^^ HELP: at least one lifetime must be borrowed
s: &'a str,
}
fn main() {}

10
test_suite/tests/compile-fail/borrow/no_lifetimes.rs Normal file
View File

@ -0,0 +1,10 @@
#[macro_use]
extern crate serde_derive;
#[derive(Deserialize)] //~ ERROR: proc-macro derive panicked
struct Test {
#[serde(borrow)] //~^^ HELP: field `s` has no lifetimes to borrow
s: String,
}
fn main() {}

10
test_suite/tests/compile-fail/borrow/wrong_lifetime.rs Normal file
View File

@ -0,0 +1,10 @@
#[macro_use]
extern crate serde_derive;
#[derive(Deserialize)] //~ ERROR: proc-macro derive panicked
struct Test<'a> {
#[serde(borrow = "'b")] //~^^ HELP: field `s` does not have lifetime 'b
s: &'a str,
}
fn main() {}

9
test_suite/tests/compile-fail/str_ref_deser.rs
View File

@ -1,9 +0,0 @@
#[macro_use]
extern crate serde_derive;
#[derive(Serialize, Deserialize)] //~ ERROR: proc-macro derive panicked
struct Test<'a> {
s: &'a str, //~^^ HELP: Serde does not support deserializing fields of type &str
}
fn main() {}