Update fbcode and xplat Rust toolchain

Summary:
Release notes: https://blog.rust-lang.org/2024/06/13/Rust-1.79.0.html

Stabilized features:

- `absolute_path`
- `associated_type_bounds`
- `inline_const`
- `pointer_is_aligned`
- `slice_ptr_len`

This release raises a new warning when a trait impl contains a signature that is more refined than the corresponding signature in the trait, impacting `buck2_query`.

```lang=text
warning: impl trait in impl method signature does not match trait method signature
  --> fbcode/buck2/app/buck2_query/src/query/environment/tests.rs:73:30
   |
73 |     fn deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
  ::: fbcode/buck2/app/buck2_query/src/query/environment.rs:98:30
   |
98 |     fn deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a;
   |                              ----------------------------------------------- return type from trait method defined here
   |
   = note: add `#[allow(refining_impl_trait)]` if it is intended for this to be part of the public API of this crate
   = note: we are soliciting feedback, see issue #121718 <rust-lang/rust#121718> for more information
   = note: `#[warn(refining_impl_trait_internal)]` on by default
help: replace the return type so that it matches the trait
   |
73 |     fn deps<'a>(&'a self) -> impl Iterator<Item = &'a <Self as node::LabeledNode>::Key> + std::marker::Send + 'a {
   |                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

It also contains changes to the `dead_code` lint, which are addressed in {D59622902} and {D59623034}.

Reviewed By: zertosh

Differential Revision: D58982552

fbshipit-source-id: a17eaf91d07234209fddf5cbdebce4424dda57ae

Author: David Tolnay

HACKING.md

@@ -22,8 +22,8 @@ cargo install --path=app/buck2
 Or, alternatively, install it directly from GitHub:
 
 ```sh
-rustup install nightly-2024-03-17
-cargo +nightly-2024-03-17 install --git https://github.com/facebook/buck2.git buck2
+rustup install nightly-2024-04-28
+cargo +nightly-2024-04-28 install --git https://github.com/facebook/buck2.git buck2
 ```
 
 ### Side note: using [Nix] to compile the source

app/buck2_core/src/lib.rs

@@ -17,7 +17,6 @@
 #![feature(io_error_more)]
 #![feature(once_cell_try)]
 #![feature(try_blocks)]
-#![cfg_attr(windows, feature(absolute_path))]
 #![feature(used_with_arg)]
 #![feature(let_chains)]
 

app/buck2_query/src/query/environment/tests.rs

@@ -70,23 +70,23 @@ impl QueryTarget for TestTarget {
         unimplemented!()
     }
 
-    fn deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
+    fn deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
         Box::new(self.deps.iter())
     }
 
-    fn exec_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
+    fn exec_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
         Box::new(std::iter::empty())
     }
 
-    fn target_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
+    fn target_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
         Box::new(std::iter::empty())
     }
 
-    fn configuration_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
+    fn configuration_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
         Box::new(std::iter::empty())
     }
 
-    fn toolchain_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
+    fn toolchain_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
         Box::new(std::iter::empty())
     }
 

app/buck2_query/src/query/syntax/simple/eval/tests.rs

@@ -70,24 +70,39 @@ impl QueryTarget for Target {
         unimplemented!()
     }
 
-    fn deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-        unimplemented!()
+    fn deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+        let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+        unimplemented!();
+        #[allow(unreachable_code)]
+        _iterator
     }
 
-    fn exec_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-        unimplemented!()
+    fn exec_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+        let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+        unimplemented!();
+        #[allow(unreachable_code)]
+        _iterator
     }
 
-    fn target_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-        unimplemented!()
+    fn target_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+        let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+        unimplemented!();
+        #[allow(unreachable_code)]
+        _iterator
     }
 
-    fn configuration_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-        unimplemented!()
+    fn configuration_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+        let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+        unimplemented!();
+        #[allow(unreachable_code)]
+        _iterator
     }
 
-    fn toolchain_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-        unimplemented!()
+    fn toolchain_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+        let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+        unimplemented!();
+        #[allow(unreachable_code)]
+        _iterator
     }
 
     fn special_attrs_for_each<E, F: FnMut(&str, &Self::Attr<'_>) -> Result<(), E>>(

app/buck2_query/src/query/traversal.rs

@@ -308,20 +308,32 @@ mod tests {
             unimplemented!()
         }
 
-        fn exec_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-            unimplemented!()
+        fn exec_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+            let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+            unimplemented!();
+            #[allow(unreachable_code)]
+            _iterator
         }
 
-        fn target_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-            unimplemented!()
+        fn target_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+            let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+            unimplemented!();
+            #[allow(unreachable_code)]
+            _iterator
         }
 
-        fn configuration_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-            unimplemented!()
+        fn configuration_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+            let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+            unimplemented!();
+            #[allow(unreachable_code)]
+            _iterator
         }
 
-        fn toolchain_deps<'a>(&'a self) -> Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a> {
-            unimplemented!()
+        fn toolchain_deps<'a>(&'a self) -> impl Iterator<Item = &'a Self::Key> + Send + 'a {
+            let _iterator: Box<dyn Iterator<Item = &'a Self::Key> + Send + 'a>;
+            unimplemented!();
+            #[allow(unreachable_code)]
+            _iterator
         }
     }
 

docs/getting_started.md

@@ -18,8 +18,8 @@ To get started, first install [rustup](https://rustup.rs/), then compile the
 `buck2` executable:
 
 ```bash
-rustup install nightly-2024-03-17
-cargo +nightly-2024-03-17 install --git https://github.com/facebook/buck2.git buck2
+rustup install nightly-2024-04-28
+cargo +nightly-2024-04-28 install --git https://github.com/facebook/buck2.git buck2
 ```
 
 The above commands install `buck2` into a suitable directory, such as

gazebo/gazebo/src/ext/str.rs

@@ -13,8 +13,8 @@ use std::str::pattern::*;
 /// Extension traits on [`str`].
 ///
 /// Set the configuration option `str_pattern_extensions` to enable the associated methods.
-/// The setting `str_pattern_extensions` requires the unstable features
-/// `pattern` and `associated_type_bounds`, so only works with Rust nightly.
+/// The setting `str_pattern_extensions` requires the unstable feature `pattern`,
+/// so only works with Rust nightly.
 pub trait StrExt {
     /// Like `split`, but only separates off the first element. For example:
     ///

gazebo/gazebo/src/lib.rs

@@ -8,7 +8,6 @@
  */
 
 #![cfg_attr(feature = "str_pattern_extensions", feature(pattern))]
-#![cfg_attr(feature = "str_pattern_extensions", feature(associated_type_bounds))]
 
 //! A collection of well-tested primitives that have been useful. Most modules stand alone.
 

rust-toolchain

@@ -9,6 +9,6 @@
 #   * NOTE: You may have to change this file in a follow up commit as ocamlrep
 #     has a dependency on buck2 git trunk.
 
-# @rustc_version: rustc 1.78.0-nightly (766bdce74 2024-03-16)
-channel = "nightly-2024-03-17"
+# @rustc_version: rustc 1.79.0-nightly (aed2187d5 2024-04-27)
+channel = "nightly-2024-04-28"
 components = ["llvm-tools-preview","rustc-dev","rust-src"]