Handle various attribute parsing error cases

This commit is contained in:
David Tolnay 2016-09-27 00:40:37 -07:00
parent 40b874214a
commit 7e441e5110
No known key found for this signature in database
GPG Key ID: F9BA143B95FF6D82

View File

@ -1,5 +1,5 @@
use Ctxt;
use syn::{self, Ident};
use syn;
// This module handles parsing of `#[serde(...)]` attributes. The entrypoints
// are `attr::Item::from_ast`, `attr::Variant::from_ast`, and
@ -106,7 +106,7 @@ impl Item {
match meta_item {
// Parse `#[serde(rename="foo")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "rename" => {
if let Ok(s) = get_string_from_lit(cx, name, lit) {
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);
}
@ -127,7 +127,7 @@ impl Item {
// Parse `#[serde(bound="D: Serialize")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "bound" => {
if let Ok(where_predicates) = parse_lit_into_where(cx, name, lit) {
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);
}
@ -193,7 +193,7 @@ impl Variant {
match meta_item {
// Parse `#[serde(rename="foo")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "rename" => {
if let Ok(s) = get_string_from_lit(cx, name, lit) {
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);
}
@ -279,7 +279,7 @@ impl Field {
match meta_item {
// Parse `#[serde(rename="foo")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "rename" => {
if let Ok(s) = get_string_from_lit(cx, name, lit) {
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);
}
@ -300,7 +300,7 @@ impl Field {
// Parse `#[serde(default="...")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "default" => {
if let Ok(path) = parse_lit_into_path(cx, name, lit) {
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
default.set(FieldDefault::Path(path));
}
}
@ -317,28 +317,28 @@ impl Field {
// Parse `#[serde(skip_serializing_if="...")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "skip_serializing_if" => {
if let Ok(path) = parse_lit_into_path(cx, name, lit) {
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
skip_serializing_if.set(path);
}
}
// Parse `#[serde(serialize_with="...")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "serialize_with" => {
if let Ok(path) = parse_lit_into_path(cx, name, lit) {
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
serialize_with.set(path);
}
}
// Parse `#[serde(deserialize_with="...")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "deserialize_with" => {
if let Ok(path) = parse_lit_into_path(cx, name, lit) {
if let Ok(path) = parse_lit_into_path(cx, name.as_ref(), lit) {
deserialize_with.set(path);
}
}
// Parse `#[serde(bound="D: Serialize")]`
syn::MetaItem::NameValue(ref name, ref lit) if name == "bound" => {
if let Ok(where_predicates) = parse_lit_into_where(cx, name, lit) {
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);
}
@ -423,31 +423,32 @@ type SerAndDe<T> = (Option<T>, Option<T>);
fn get_ser_and_de<T, F>(
cx: &Ctxt,
attribute: &'static str,
attr_name: &'static str,
items: &[syn::MetaItem],
f: F
) -> Result<SerAndDe<T>, ()>
where F: Fn(&Ctxt, &Ident, &syn::Lit) -> Result<T, ()>,
where F: Fn(&Ctxt, &str, &str, &syn::Lit) -> Result<T, ()>,
{
let mut ser_item = Attr::none(cx, attribute);
let mut de_item = Attr::none(cx, attribute);
let mut ser_item = Attr::none(cx, attr_name);
let mut de_item = Attr::none(cx, attr_name);
for item in items {
match *item {
syn::MetaItem::NameValue(ref name, ref lit) if name == "serialize" => {
if let Ok(v) = f(cx, name, lit) {
if let Ok(v) = f(cx, attr_name, name.as_ref(), lit) {
ser_item.set(v);
}
}
syn::MetaItem::NameValue(ref name, ref lit) if name == "deserialize" => {
if let Ok(v) = f(cx, name, lit) {
if let Ok(v) = f(cx, attr_name, name.as_ref(), lit) {
de_item.set(v);
}
}
_ => {
cx.error(format!("bad {} attribute", attribute));
cx.error(format!("malformed {0} attribute, expected `{0}(serialize = ..., deserialize = ...)`",
attr_name));
return Err(());
}
}
@ -479,29 +480,28 @@ pub fn get_serde_meta_items(attr: &syn::Attribute) -> Option<Vec<syn::MetaItem>>
}
}
fn get_string_from_lit(_cx: &Ctxt, _name: &Ident, lit: &syn::Lit) -> Result<String, ()> {
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 {
// TODO handle error
cx.error(format!("expected serde {} attribute to be a string: `{} = \"...\"`",
attr_name, meta_item_name));
Err(())
}
}
fn parse_lit_into_path(cx: &Ctxt, name: &Ident, lit: &syn::Lit) -> Result<syn::Path, ()> {
let string = try!(get_string_from_lit(cx, name, lit));
// TODO handle error
Ok(syn::parse_path(&string).unwrap())
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, name: &Ident, lit: &syn::Lit) -> Result<Vec<syn::WherePredicate>, ()> {
let string = try!(get_string_from_lit(cx, name, lit));
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);
// TODO handle error
Ok(syn::parse_where_clause(&where_string).unwrap().predicates)
syn::parse_where_clause(&where_string).map(|wh| wh.predicates).map_err(|err| cx.error(err))
}