Implement serialization and deserialization for wasmtime_environ::collections::PrimaryMap (#12560)

Author: fitzgen

crates/core/src/alloc/vec.rs

@@ -270,6 +270,12 @@ impl<T> From<StdVec<T>> for Vec<T> {
     }
 }
 
+impl<T> From<Vec<T>> for StdVec<T> {
+    fn from(v: Vec<T>) -> Self {
+        v.inner
+    }
+}
+
 impl<T> From<Box<[T]>> for Vec<T> {
     fn from(boxed_slice: Box<[T]>) -> Self {
         Self::from(StdVec::from(boxed_slice))

crates/environ/src/collections/primary_map.rs

@@ -3,11 +3,12 @@ use core::{
     ops::{Index, IndexMut},
 };
 use cranelift_entity::EntityRef;
+use serde::{Serialize, ser::SerializeSeq};
 use wasmtime_core::error::OutOfMemory;
 
 /// Like [`cranelift_entity::PrimaryMap`] but enforces fallible allocation for
 /// all methods that allocate.
-#[derive(Clone, Hash, PartialEq, Eq)]
+#[derive(Hash, PartialEq, Eq)]
 pub struct PrimaryMap<K, V>
 where
     K: EntityRef,
@@ -36,6 +37,48 @@ where
     }
 }
 
+impl<K, V> From<crate::collections::Vec<V>> for PrimaryMap<K, V>
+where
+    K: EntityRef,
+{
+    fn from(values: crate::collections::Vec<V>) -> Self {
+        let values: ::alloc::vec::Vec<V> = values.into();
+        let inner = cranelift_entity::PrimaryMap::from(values);
+        Self { inner }
+    }
+}
+
+impl<K, V> serde::ser::Serialize for PrimaryMap<K, V>
+where
+    K: EntityRef,
+    V: Serialize,
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        let mut seq = serializer.serialize_seq(Some(self.len()))?;
+        for val in self.values() {
+            seq.serialize_element(val)?;
+        }
+        seq.end()
+    }
+}
+
+impl<'de, K, V> serde::de::Deserialize<'de> for PrimaryMap<K, V>
+where
+    K: EntityRef,
+    V: serde::de::Deserialize<'de>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let v: crate::collections::Vec<V> = serde::de::Deserialize::deserialize(deserializer)?;
+        Ok(Self::from(v))
+    }
+}
+
 impl<K, V> PrimaryMap<K, V>
 where
     K: EntityRef,