Bug 1716518 - Upgrade lazycell to v1.3.0. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D117808

Cargo.lock

@@ -2705,9 +2705,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "lazycell"
-version = "1.2.1"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "leb128"

third_party/rust/lazycell/.cargo-checksum.json

@@ -1 +1 @@
-{"files":{"CHANGELOG.md":"0aa4629e399d08ad3a446366d465449a5e92ba95aac708be76961100a9c7df48","Cargo.toml":"15c8e40c3c9ed8635ed338b633d343702b6f4a90dcd5aa759673d31af401dd0a","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"03f6ccb4e6040abccf12b31551bbbd1800a5069a17950bbd6db850d85744800f","README.md":"c0798b2c9b0d3b9c0da509fdd9001eb2d80e6ed0850d312e36136ac269dbe49f","src/lib.rs":"7ea882864c246d78be6ea3558b92a8a7dd5732f55556cd641efb7a8caf4e64e3"},"package":"b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"}
+{"files":{"CHANGELOG.md":"54036052985525a153f9e6c9dda6a143b7494a477908fb28f5705f92dd387059","Cargo.toml":"79f5da117603f75361b9a7309f102a9ab70b66d5c1c269a30f66fdea58ccc657","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"03f6ccb4e6040abccf12b31551bbbd1800a5069a17950bbd6db850d85744800f","README.md":"26e4440387d4fc898f377eb5394f3432f8625ed8aa46e02ffb61aac8b2032967","src/lib.rs":"3fcef569bd4feb760925e34aef0e66739a0827cbc1b26ae033f57e322c3a2515","src/serde_impl.rs":"4903fb722748e91bdc4b481c7f3309e79e962f75c9717e7e13edcccd0242a52d"},"package":"830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"}

third_party/rust/lazycell/CHANGELOG.md

@@ -1,3 +1,22 @@
+<a name="v1.3.0"></a>
+## v1.3.0 (2020-08-12)
+
+
+#### Bug Fixes
+
+*   Add custom `impl Default` to support non-Default-able `<T>` types ([b49f4eab](https://github.com/indiv0/lazycell/commit/b49f4eabec49c0a5146ef01017c2506a3c357180))
+* **lazycell:**  Fix unsound aliasing in `LazyCell::fill` ([e789ac1a](https://github.com/indiv0/lazycell/commit/e789ac1a99010ad79c2d09c761fec6d67053647d), closes [#98](https://github.com/indiv0/lazycell/issues/98))
+
+#### Features
+
+*   Implement serde support ([e728a0b6](https://github.com/indiv0/lazycell/commit/e728a0b680e607b793a81b5af7bf7f1d2c0eb5e5))
+
+#### Documentation
+
+*   fix typo ([5f5ba9d5](https://github.com/indiv0/lazycell/commit/5f5ba9d5ac3364f8376c0c872c2e5094974385ba))
+
+
+
 <a name="v1.2.1"></a>
 ## v1.2.1 (2018-12-03)
 

third_party/rust/lazycell/Cargo.toml

@@ -3,7 +3,7 @@
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
 # with all versions of Cargo and also rewrite `path` dependencies
-# to registry (e.g. crates.io) dependencies
+# to registry (e.g., crates.io) dependencies
 #
 # If you believe there's an error in this file please file an
 # issue against the rust-lang/cargo repository. If you're
@@ -12,7 +12,7 @@
 
 [package]
 name = "lazycell"
-version = "1.2.1"
+version = "1.3.0"
 authors = ["Alex Crichton <alex@alexcrichton.com>", "Nikita Pekin <contact@nikitapek.in>"]
 include = ["CHANGELOG.md", "Cargo.toml", "LICENSE-MIT", "LICENSE-APACHE", "README.md", "src/**/*.rs"]
 description = "A library providing a lazily filled Cell struct"
@@ -25,6 +25,10 @@ repository = "https://github.com/indiv0/lazycell"
 version = "0.0"
 optional = true
 
+[dependencies.serde]
+version = "^1"
+optional = true
+
 [features]
 nightly = []
 nightly-testing = ["clippy", "nightly"]

third_party/rust/lazycell/README.md

@@ -7,6 +7,7 @@
     </tr>
     <tr>
         <td colspan="2">
+            <a href="https://crates.io/crates/lazycell" title="Crates.io downloads"><img src="https://img.shields.io/crates/d/lazycell.svg" alt="cargo-downloads-badge"></img></a>
             <a href="https://indiv0.github.io/lazycell/lazycell" title="API Docs"><img src="https://img.shields.io/badge/API-docs-blue.svg" alt="api-docs-badge"></img></a>
             <a href="https://crates.io/crates/lazycell" title="Crates.io"><img src="https://img.shields.io/crates/v/lazycell.svg" alt="crates-io"></img></a>
             <a href="#license" title="License: MIT/Apache-2.0"><img src="https://img.shields.io/crates/l/lazycell.svg" alt="license-badge"></img></a>
@@ -30,7 +31,7 @@ Add the following to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-lazycell = "1.2"
+lazycell = "1.3"
 ```
 
 And in your `lib.rs` or `main.rs`:

third_party/rust/lazycell/src/lib.rs

@@ -1,5 +1,5 @@
 // Original work Copyright (c) 2014 The Rust Project Developers
-// Modified work Copyright (c) 2016-2018 Nikita Pekin and the lazycell contributors
+// Modified work Copyright (c) 2016-2020 Nikita Pekin and the lazycell contributors
 // See the README.md file at the top-level directory of this distribution.
 //
 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
@@ -48,6 +48,11 @@
 #[cfg(not(test))]
 #[macro_use]
 extern crate core as std;
+#[cfg(feature = "serde")]
+extern crate serde;
+
+#[cfg(feature = "serde")]
+mod serde_impl;
 
 use std::cell::UnsafeCell;
 use std::mem;
@@ -58,7 +63,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 /// A `LazyCell` is completely frozen once filled, **unless** you have `&mut`
 /// access to it, in which case `LazyCell::borrow_mut` may be used to mutate the
 /// contents.
-#[derive(Debug, Default)]
+#[derive(Debug)]
 pub struct LazyCell<T> {
     inner: UnsafeCell<Option<T>>,
 }
@@ -71,12 +76,13 @@ impl<T> LazyCell<T> {
 
     /// Put a value into this cell.
     ///
-    /// This function will return `Err(value)` is the cell is already full.
+    /// This function will return `Err(value)` if the cell is already full.
     pub fn fill(&self, value: T) -> Result<(), T> {
-        let slot = unsafe { &mut *self.inner.get() };
+        let slot = unsafe { &*self.inner.get() };
         if slot.is_some() {
             return Err(value);
         }
+        let slot = unsafe { &mut *self.inner.get() };
         *slot = Some(value);
 
         Ok(())
@@ -215,6 +221,12 @@ impl<T: Copy> LazyCell<T> {
     }
 }
 
+impl<T> Default for LazyCell<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl <T: Clone> Clone for LazyCell<T> {
     /// Create a clone of this `LazyCell`
     ///
@@ -232,7 +244,7 @@ const LOCK: usize = 1;
 const SOME: usize = 2;
 
 /// A lazily filled and thread-safe `Cell`, with frozen contents.
-#[derive(Debug, Default)]
+#[derive(Debug)]
 pub struct AtomicLazyCell<T> {
     inner: UnsafeCell<Option<T>>,
     state: AtomicUsize,
@@ -252,7 +264,7 @@ impl<T> AtomicLazyCell<T> {
 
     /// Put a value into this cell.
     ///
-    /// This function will return `Err(value)` is the cell is already full.
+    /// This function will return `Err(value)` if the cell is already full.
     pub fn fill(&self, t: T) -> Result<(), T> {
         if NONE != self.state.compare_and_swap(NONE, LOCK, Ordering::Acquire) {
             return Err(t);
@@ -325,6 +337,12 @@ impl<T: Copy> AtomicLazyCell<T> {
     }
 }
 
+impl<T> Default for AtomicLazyCell<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<T: Clone> Clone for AtomicLazyCell<T> {
     /// Create a clone of this `AtomicLazyCell`
     ///
@@ -646,4 +664,17 @@ mod tests {
         assert_eq!(clone2.borrow(), Some(&4));
         assert_eq!(cell.borrow(), Some(&2));
     }
+
+    #[test]
+    fn default() {
+        #[derive(Default)]
+        struct Defaultable;
+        struct NonDefaultable;
+
+        let _: LazyCell<Defaultable> = LazyCell::default();
+        let _: LazyCell<NonDefaultable> = LazyCell::default();
+
+        let _: AtomicLazyCell<Defaultable> = AtomicLazyCell::default();
+        let _: AtomicLazyCell<NonDefaultable> = AtomicLazyCell::default();
+    }
 }

third_party/rust/lazycell/src/serde_impl.rs

@@ -0,0 +1,86 @@
+// Copyright (c) 2020 Nikita Pekin and the lazycell contributors
+// See the README.md file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.use serde::ser::{Serialize, Serializer};
+use serde::ser::{Serialize, Serializer};
+use serde::de::{self, Deserialize, Deserializer, Visitor};
+
+use std::fmt;
+use std::marker::PhantomData;
+
+use super::{LazyCell, AtomicLazyCell};
+
+impl<T: Serialize> Serialize for LazyCell<T> {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        match self.borrow() {
+            Some(val) => serializer.serialize_some(val),
+            None => serializer.serialize_none()
+        }
+    }
+}
+
+
+impl<T: Serialize> Serialize for AtomicLazyCell<T> {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        match self.borrow() {
+            Some(val) => serializer.serialize_some(val),
+            None => serializer.serialize_none()
+        }
+    }
+}
+
+struct LazyCellVisitor<T>(PhantomData<*const T>);
+impl<'de, T: Deserialize<'de>> Visitor<'de> for LazyCellVisitor<T> {
+    type Value = LazyCell<T>;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a LazyCell")
+    }
+
+    fn visit_some<D: Deserializer<'de>>(self, deserializer: D) -> Result<Self::Value, D::Error> {
+        let mut cell = LazyCell::new();
+        cell.replace(T::deserialize(deserializer)?);
+        Ok(cell)
+    }
+
+    fn visit_none<E: de::Error>(self) -> Result<Self::Value, E> {
+        Ok(LazyCell::new())
+    }
+}
+
+impl<'de, T: Deserialize<'de>> Deserialize<'de> for LazyCell<T> {
+    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        deserializer.deserialize_option(LazyCellVisitor(PhantomData))
+    }
+}
+
+
+struct AtomicLazyCellVisitor<T>(PhantomData<*const T>);
+impl<'de, T: Deserialize<'de>> Visitor<'de> for AtomicLazyCellVisitor<T> {
+    type Value = AtomicLazyCell<T>;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("an AtomicLazyCell")
+    }
+
+    fn visit_some<D: Deserializer<'de>>(self, deserializer: D) -> Result<Self::Value, D::Error> {
+        let mut cell = AtomicLazyCell::new();
+        cell.replace(T::deserialize(deserializer)?);
+        Ok(cell)
+    }
+
+    fn visit_none<E: de::Error>(self) -> Result<Self::Value, E> {
+        Ok(AtomicLazyCell::new())
+    }
+}
+
+
+impl<'de, T: Deserialize<'de>> Deserialize<'de> for AtomicLazyCell<T> {
+    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        deserializer.deserialize_option(AtomicLazyCellVisitor(PhantomData))
+    }
+}