feat: Stabilize Edition 2024 (#14828)

### What does this PR try to resolve?

### How should we test and review this PR?

### Additional information

Author: ehuss

src/cargo/core/features.rs

@@ -162,6 +162,7 @@ pub type AllowFeatures = BTreeSet<String>;
 /// - Set [`LATEST_UNSTABLE`] to None.
 /// - Set [`LATEST_STABLE`] to the new version.
 /// - Update [`is_stable`] to `true`.
+/// - Set [`first_version`] to the version it will be released.
 /// - Set the editionNNNN feature to stable in the [`features!`] macro invocation below.
 /// - Update any tests that are affected.
 /// - Update the man page for the `--edition` flag.
@@ -178,6 +179,7 @@ pub type AllowFeatures = BTreeSet<String>;
 /// [`LATEST_UNSTABLE`]: Edition::LATEST_UNSTABLE
 /// [`LATEST_STABLE`]: Edition::LATEST_STABLE
 /// [this example]: https://github.com/rust-lang/cargo/blob/3ebb5f15a940810f250b68821149387af583a79e/src/doc/src/reference/unstable.md?plain=1#L1238-L1264
+/// [`first_version`]: Edition::first_version
 /// [`is_stable`]: Edition::is_stable
 /// [`toml`]: crate::util::toml
 /// [`features!`]: macro.features.html
@@ -200,9 +202,9 @@ impl Edition {
     /// The latest edition that is unstable.
     ///
     /// This is `None` if there is no next unstable edition.
-    pub const LATEST_UNSTABLE: Option<Edition> = Some(Edition::Edition2024);
+    pub const LATEST_UNSTABLE: Option<Edition> = None;
     /// The latest stable edition.
-    pub const LATEST_STABLE: Edition = Edition::Edition2021;
+    pub const LATEST_STABLE: Edition = Edition::Edition2024;
     pub const ALL: &'static [Edition] = &[
         Self::Edition2015,
         Self::Edition2018,
@@ -223,7 +225,7 @@ impl Edition {
             Edition2015 => None,
             Edition2018 => Some(semver::Version::new(1, 31, 0)),
             Edition2021 => Some(semver::Version::new(1, 56, 0)),
-            Edition2024 => None,
+            Edition2024 => Some(semver::Version::new(1, 85, 0)),
         }
     }
 
@@ -234,7 +236,7 @@ impl Edition {
             Edition2015 => true,
             Edition2018 => true,
             Edition2021 => true,
-            Edition2024 => false,
+            Edition2024 => true,
         }
     }
 
@@ -507,7 +509,7 @@ features! {
     (stable, workspace_inheritance, "1.64", "reference/unstable.html#workspace-inheritance"),
 
     /// Support for 2024 edition.
-    (unstable, edition2024, "", "reference/unstable.html#edition-2024"),
+    (stable, edition2024, "1.85", "reference/manifest.html#the-edition-field"),
 
     /// Allow setting trim-paths in a profile to control the sanitisation of file paths in build outputs.
     (unstable, trim_paths, "", "reference/unstable.html#profile-trim-paths-option"),

src/cargo/util/toml/embedded.rs

@@ -567,7 +567,7 @@ autoexamples = false
 autolib = false
 autotests = false
 build = false
-edition = "2021"
+edition = "2024"
 name = "test-"
 
 [profile.release]
@@ -605,7 +605,7 @@ autoexamples = false
 autolib = false
 autotests = false
 build = false
-edition = "2021"
+edition = "2024"
 name = "test-"
 
 [profile.release]

src/cargo/util/toml/mod.rs

@@ -1217,9 +1217,7 @@ pub fn to_real_manifest(
     //     features.require(Feature::edition20xx())?;
     // }
     // ```
-    if edition == Edition::Edition2024 {
-        features.require(Feature::edition2024())?;
-    } else if !edition.is_stable() {
+    if !edition.is_stable() {
         // Guard in case someone forgets to add .require()
         return Err(util::errors::internal(format!(
             "edition {} should be gated",

src/doc/man/generated_txt/cargo-init.txt

@@ -30,7 +30,7 @@ OPTIONS
            Create a package with a library target (src/lib.rs).
 
        --edition edition
-           Specify the Rust edition to use. Default is 2021. Possible values:
+           Specify the Rust edition to use. Default is 2024. Possible values:
            2015, 2018, 2021, 2024
 
        --name name

src/doc/man/generated_txt/cargo-new.txt

@@ -25,7 +25,7 @@ OPTIONS
            Create a package with a library target (src/lib.rs).
 
        --edition edition
-           Specify the Rust edition to use. Default is 2021. Possible values:
+           Specify the Rust edition to use. Default is 2024. Possible values:
            2015, 2018, 2021, 2024
 
        --name name

src/doc/man/includes/options-new.md

@@ -10,7 +10,7 @@ Create a package with a library target (`src/lib.rs`).
 {{/option}}
 
 {{#option "`--edition` _edition_" }}
-Specify the Rust edition to use. Default is 2021.
+Specify the Rust edition to use. Default is 2024.
 Possible values: 2015, 2018, 2021, 2024
 {{/option}}
 

src/doc/src/commands/cargo-init.md

@@ -39,7 +39,7 @@ This is the default behavior.</dd>
 
 
 <dt class="option-term" id="option-cargo-init---edition"><a class="option-anchor" href="#option-cargo-init---edition"></a><code>--edition</code> <em>edition</em></dt>
-<dd class="option-desc">Specify the Rust edition to use. Default is 2021.
+<dd class="option-desc">Specify the Rust edition to use. Default is 2024.
 Possible values: 2015, 2018, 2021, 2024</dd>
 
 

src/doc/src/commands/cargo-new.md

@@ -34,7 +34,7 @@ This is the default behavior.</dd>
 
 
 <dt class="option-term" id="option-cargo-new---edition"><a class="option-anchor" href="#option-cargo-new---edition"></a><code>--edition</code> <em>edition</em></dt>
-<dd class="option-desc">Specify the Rust edition to use. Default is 2021.
+<dd class="option-desc">Specify the Rust edition to use. Default is 2024.
 Possible values: 2015, 2018, 2021, 2024</dd>
 
 

src/doc/src/getting-started/first-steps.md

@@ -33,7 +33,7 @@ This is all we need to get started. First, let’s check out `Cargo.toml`:
 [package]
 name = "hello_world"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 ```

src/doc/src/guide/creating-a-new-project.md

@@ -29,7 +29,7 @@ Let’s take a closer look at `Cargo.toml`:
 [package]
 name = "hello_world"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 

src/doc/src/guide/dependencies.md

@@ -35,7 +35,7 @@ crates:
 [package]
 name = "hello_world"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 time = "0.1.12"

src/doc/src/reference/build-script-examples.md

@@ -49,7 +49,7 @@ Here we can see that we have a `build.rs` build script and our binary in
 [package]
 name = "hello-from-generated-code"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 ```
 
 Let’s see what’s inside the build script:
@@ -148,7 +148,7 @@ Pretty similar to before! Next, the manifest:
 [package]
 name = "hello-world-from-c"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 ```
 
 For now we’re not going to use any build dependencies, so let’s take a look at
@@ -298,7 +298,7 @@ with `pkg-config` installed. Let's start by setting up the manifest:
 [package]
 name = "libz-sys"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 links = "z"
 
 [build-dependencies]
@@ -385,7 +385,7 @@ Here's an example:
 [package]
 name = "zuser"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 libz-sys = "1.0.25"

src/doc/src/reference/manifest.md

@@ -151,12 +151,12 @@ examples, etc.
 ```toml
 [package]
 # ...
-edition = '2021'
+edition = '2024'
 ```
 
 Most manifests have the `edition` field filled in automatically by [`cargo new`]
 with the latest stable edition. By default `cargo new` creates a manifest with
-the 2021 edition currently.
+the 2024 edition currently.
 
 If the `edition` field is not present in `Cargo.toml`, then the 2015 edition is
 assumed for backwards compatibility. Note that all manifests

src/doc/src/reference/registries.md

@@ -38,7 +38,7 @@ in `Cargo.toml`:
 [package]
 name = "my-project"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 other-crate = { version = "1.0", registry = "my-registry" }

src/doc/src/reference/resolver.md

@@ -507,7 +507,7 @@ resolver = "2"
 - `"2"` ([`edition = "2021"`](manifest.md#the-edition-field) default): Introduces changes in [feature
 unification](#features). See the [features chapter][features-2] for more
 details.
-- `"3"` (requires Rust 1.84+): Change the default for [`resolver.incompatible-rust-versions`] from `allow` to `fallback`
+- `"3"` ([`edition = "2024"`](manifest.md#the-edition-field) default, requires Rust 1.84+): Change the default for [`resolver.incompatible-rust-versions`] from `allow` to `fallback`
 
 The resolver is a global option that affects the entire workspace. The
 `resolver` version in dependencies is ignored, only the value in the top-level

src/doc/src/reference/unstable.md

@@ -100,7 +100,6 @@ Each new feature described below should explain how to use it.
     * [codegen-backend](#codegen-backend) --- Select the codegen backend used by rustc.
     * [per-package-target](#per-package-target) --- Sets the `--target` to use for each individual package.
     * [artifact dependencies](#artifact-dependencies) --- Allow build artifacts to be included into other build artifacts and build them for different targets.
-    * [Edition 2024](#edition-2024) — Adds support for the 2024 Edition.
     * [Profile `trim-paths` option](#profile-trim-paths-option) --- Control the sanitization of file paths in build outputs.
     * [`[lints.cargo]`](#lintscargo) --- Allows configuring lints for Cargo.
     * [path bases](#path-bases) --- Named base directories for path dependencies.
@@ -1363,32 +1362,6 @@ Differences between `cargo run --manifest-path <path>` and `cargo <path>`
 
 ### Documentation Updates
 
-## Edition 2024
-* Tracking Issue: (none created yet)
-* RFC: [rust-lang/rfcs#3501](https://github.com/rust-lang/rfcs/pull/3501)
-
-Support for the 2024 [edition] can be enabled by adding the `edition2024`
-unstable feature to the top of `Cargo.toml`:
-
-```toml
-cargo-features = ["edition2024"]
-
-[package]
-name = "my-package"
-version = "0.1.0"
-edition = "2024"
-```
-
-If you want to transition an existing project from a previous edition, then
-`cargo fix --edition` can be used on the nightly channel. After running `cargo
-fix`, you can switch the edition to 2024 as illustrated above.
-
-This feature is very unstable, and is only intended for early testing and
-experimentation. Future nightly releases may introduce changes for the 2024
-edition that may break your build.
-
-[edition]: ../../edition-guide/index.html
-
 ## Profile `trim-paths` option
 
 * Tracking Issue: [rust-lang/cargo#12137](https://github.com/rust-lang/cargo/issues/12137)
@@ -2013,3 +1986,10 @@ default behavior.
 
 See the [build script documentation](build-scripts.md#rustc-check-cfg) for information
 about specifying custom cfgs.
+
+## Edition 2024
+
+The 2024 edition has been stabilized in the 1.85 release.
+See the [`edition` field](manifest.md#the-edition-field) for more information on setting the edition.
+See [`cargo fix --edition`](../commands/cargo-fix.md) and [The Edition Guide](../../edition-guide/index.html) for more information on migrating existing projects.
+

src/doc/src/reference/workspaces.md

@@ -76,7 +76,7 @@ resolver = "2"
 [package]
 name = "hello_world" # the name of the package
 version = "0.1.0"    # the current version, obeying semver
-edition = "2021"     # the edition, will have no effect on a resolver used in the workspace
+edition = "2024"     # the edition, will have no effect on a resolver used in the workspace
 authors = ["Alice <[email protected]>", "Bob <[email protected]>"]
 ```
 

src/etc/man/cargo-init.1

@@ -36,7 +36,7 @@ Create a package with a library target (\fBsrc/lib.rs\fR).
 .sp
 \fB\-\-edition\fR \fIedition\fR
 .RS 4
-Specify the Rust edition to use. Default is 2021.
+Specify the Rust edition to use. Default is 2024.
 Possible values: 2015, 2018, 2021, 2024
 .RE
 .sp

src/etc/man/cargo-new.1

@@ -31,7 +31,7 @@ Create a package with a library target (\fBsrc/lib.rs\fR).
 .sp
 \fB\-\-edition\fR \fIedition\fR
 .RS 4
-Specify the Rust edition to use. Default is 2021.
+Specify the Rust edition to use. Default is 2024.
 Possible values: 2015, 2018, 2021, 2024
 .RE
 .sp