| use std::borrow::Cow; | 
 | use std::collections::BTreeMap; | 
 |  | 
 | pub use serde_json::Value as Json; | 
 | use serde_json::{Map, Number, json}; | 
 |  | 
 | use crate::spec::TargetMetadata; | 
 |  | 
 | pub trait ToJson { | 
 |     fn to_json(&self) -> Json; | 
 | } | 
 |  | 
 | impl ToJson for Json { | 
 |     fn to_json(&self) -> Json { | 
 |         self.clone() | 
 |     } | 
 | } | 
 |  | 
 | macro_rules! to_json_impl_num { | 
 |     ($($t:ty), +) => ( | 
 |         $(impl ToJson for $t { | 
 |             fn to_json(&self) -> Json { | 
 |                 Json::Number(Number::from(*self)) | 
 |             } | 
 |         })+ | 
 |     ) | 
 | } | 
 |  | 
 | to_json_impl_num! { isize, i8, i16, i32, i64, usize, u8, u16, u32, u64 } | 
 |  | 
 | impl ToJson for bool { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::Bool(*self) | 
 |     } | 
 | } | 
 |  | 
 | impl ToJson for str { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::String(self.to_owned()) | 
 |     } | 
 | } | 
 |  | 
 | impl ToJson for String { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::String(self.to_owned()) | 
 |     } | 
 | } | 
 |  | 
 | impl<'a> ToJson for Cow<'a, str> { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::String(self.to_string()) | 
 |     } | 
 | } | 
 |  | 
 | impl<A: ToJson> ToJson for [A] { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::Array(self.iter().map(|elt| elt.to_json()).collect()) | 
 |     } | 
 | } | 
 |  | 
 | impl<A: ToJson> ToJson for Vec<A> { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::Array(self.iter().map(|elt| elt.to_json()).collect()) | 
 |     } | 
 | } | 
 |  | 
 | impl<'a, A: ToJson> ToJson for Cow<'a, [A]> | 
 | where | 
 |     [A]: ToOwned, | 
 | { | 
 |     fn to_json(&self) -> Json { | 
 |         Json::Array(self.iter().map(|elt| elt.to_json()).collect()) | 
 |     } | 
 | } | 
 |  | 
 | impl<T: ToString, A: ToJson> ToJson for BTreeMap<T, A> { | 
 |     fn to_json(&self) -> Json { | 
 |         let mut d = Map::new(); | 
 |         for (key, value) in self { | 
 |             d.insert(key.to_string(), value.to_json()); | 
 |         } | 
 |         Json::Object(d) | 
 |     } | 
 | } | 
 |  | 
 | impl<A: ToJson> ToJson for Option<A> { | 
 |     fn to_json(&self) -> Json { | 
 |         match *self { | 
 |             None => Json::Null, | 
 |             Some(ref value) => value.to_json(), | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | impl ToJson for TargetMetadata { | 
 |     fn to_json(&self) -> Json { | 
 |         json!({ | 
 |             "description": self.description, | 
 |             "tier": self.tier, | 
 |             "host_tools": self.host_tools, | 
 |             "std": self.std, | 
 |         }) | 
 |     } | 
 | } | 
 |  | 
 | impl ToJson for rustc_abi::Endian { | 
 |     fn to_json(&self) -> Json { | 
 |         self.as_str().to_json() | 
 |     } | 
 | } | 
 |  | 
 | impl ToJson for rustc_abi::CanonAbi { | 
 |     fn to_json(&self) -> Json { | 
 |         self.to_string().to_json() | 
 |     } | 
 | } | 
 |  | 
 | macro_rules! serde_deserialize_from_str { | 
 |     ($ty:ty) => { | 
 |         impl<'de> serde::Deserialize<'de> for $ty { | 
 |             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> | 
 |             where | 
 |                 D: serde::Deserializer<'de>, | 
 |             { | 
 |                 let s = String::deserialize(deserializer)?; | 
 |                 FromStr::from_str(&s).map_err(serde::de::Error::custom) | 
 |             } | 
 |         } | 
 |     }; | 
 | } | 
 | pub(crate) use serde_deserialize_from_str; |