Support precompiled deserialize_in_place

precompiled/serde_derive/build.rs

@@ -1,3 +1,4 @@
 fn main() {
     println!("cargo:rustc-cfg=precompiled");
+    println!("cargo:rustc-cfg=feature=\"deserialize_in_place\"");
 }

precompiled/serde_derive/main.rs

@@ -3,6 +3,7 @@ extern crate proc_macro2;
 use proc_macro2::watt;
 use proc_macro2::watt::buffer::InputBuffer;
 use std::io::{self, Read, Write};
+use std::sync::atomic::Ordering;
 
 fn main() {
     let mut buf = Vec::new();
@@ -12,6 +13,10 @@ fn main() {
     let derive = match buf.read_u8() {
         0 => serde_derive::derive_serialize,
         1 => serde_derive::derive_deserialize,
+        2 => {
+            serde_derive::DESERIALIZE_IN_PLACE.store(true, Ordering::Relaxed);
+            serde_derive::derive_deserialize
+        }
         _ => unreachable!(),
     };
 

precompiled/x86_64-unknown-linux-gnu/Cargo.toml

@@ -16,6 +16,10 @@ repository = "https://github.com/serde-rs/serde"
 name = "serde_derive"
 proc-macro = true
 
+[features]
+default = []
+deserialize_in_place = []
+
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
 

precompiled/x86_64-unknown-linux-gnu/src/lib.rs

@@ -23,7 +23,7 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
 
 #[proc_macro_derive(Deserialize, attributes(serde))]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
-    derive(1, input)
+    derive(1 + cfg!(feature = "deserialize_in_place") as u8, input)
 }
 
 fn derive(select: u8, input: TokenStream) -> TokenStream {