rustdoc: generate JSON via serde

Author: euclio

Cargo.lock

@@ -3186,6 +3186,8 @@ dependencies = [
  "minifier 0.0.30 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pulldown-cmark 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.92 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 

src/librustdoc/Cargo.toml

@@ -11,5 +11,7 @@ path = "lib.rs"
 [dependencies]
 pulldown-cmark = { version = "0.5.2", default-features = false }
 minifier = "0.0.30"
+serde = { version = "1.0.82", features = ["derive"] }
+serde_json = "1.0.33"
 tempfile = "3"
 parking_lot = "0.7"

src/librustdoc/clean/cfg.rs

@@ -16,7 +16,7 @@ use syntax_pos::Span;
 
 use crate::html::escape::Escape;
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub enum Cfg {
     /// Accepts all configurations.
     True,