Merge pull request #19126 from lnicola/sync-from-rust

minor: Sync from downstream

Author: lnicola

.github/workflows/ci.yml

@@ -35,12 +35,15 @@ jobs:
             ~/.cargo/bin
           key: ${{ runner.os }}-${{ env.MDBOOK_VERSION }}--${{ env.MDBOOK_LINKCHECK2_VERSION }}--${{ env.MDBOOK_TOC_VERSION }}--${{ env.MDBOOK_MERMAID_VERSION }}
 
-      - name: Cache linkcheck
-        uses: actions/cache@v4
+      - name: Restore cached Linkcheck
+        if: github.event_name == 'schedule'
+        id: cache-linkcheck-restore
+        uses: actions/cache/restore@v4
         with:
-          path: |
-            ~/book/linkcheck
-          key: ${{ runner.os }}-${{ hashFiles('./book/linkcheck') }}
+          path: book/linkcheck/cache.json
+          key: linkcheck--${{ env.MDBOOK_LINKCHECK2_VERSION }}--${{ github.run_id }}
+          restore-keys: |
+            linkcheck--${{ env.MDBOOK_LINKCHECK2_VERSION }}--
 
       - name: Install latest nightly Rust toolchain
         if: steps.mdbook-cache.outputs.cache-hit != 'true'
@@ -59,6 +62,14 @@ jobs:
       - name: Check build
         run: ENABLE_LINKCHECK=1 mdbook build
 
+      - name: Save cached Linkcheck
+        id: cache-linkcheck-save
+        if: ${{ !cancelled() && github.event_name == 'schedule' }}
+        uses: actions/cache/save@v4
+        with:
+          path: book/linkcheck/cache.json
+          key: linkcheck--${{ env.MDBOOK_LINKCHECK2_VERSION }}--${{ github.run_id }}
+
       - name: Deploy to gh-pages
         if: github.event_name == 'push'
         run: |

.github/workflows/rustc-pull.yml

@@ -0,0 +1,85 @@
+name: rustc-pull
+
+on:
+  workflow_dispatch:
+  schedule:
+    # Run at 04:00 UTC every Monday
+    - cron: '0 4 * * 1'
+
+jobs:
+  pull:
+    if: github.repository == 'rust-lang/rustc-dev-guide'
+    runs-on: ubuntu-latest
+    outputs:
+      pr_url: ${{ steps.update-pr.outputs.pr_url }}
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          # We need the full history for josh to work
+          fetch-depth: '0'
+      - name: Install stable Rust toolchain
+        run: rustup update stable
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: "josh-sync"
+          # Cache the josh directory with checked out rustc
+          cache-directories: "/home/runner/.cache/rustc-dev-guide-josh"
+      - name: Install josh
+        run: RUSTFLAGS="--cap-lints warn" cargo +stable install josh-proxy --git https://github.com/josh-project/josh --tag r24.10.04
+      - name: Setup bot git name and email
+        run: |
+          git config --global user.name 'The rustc-dev-guide Cronjob Bot'
+          git config --global user.email 'github-actions@github.com'
+      - name: Perform rustc-pull
+        run: cargo run --manifest-path josh-sync/Cargo.toml -- rustc-pull
+      - name: Push changes to a branch
+        run: |
+          # Update a sticky branch that is used only for rustc pulls
+          BRANCH="rustc-pull"
+          git switch -c $BRANCH
+          git push -u origin $BRANCH --force
+      - name: Create pull request
+        id: update-pr
+        run: |
+          # Check if an open pull request for an rustc pull update already exists
+          # If it does, the previous push has just updated it
+          # If not, we create it now
+          RESULT=`gh pr list --author github-actions[bot] --state open -q 'map(select(.title=="Rustc pull update")) | length' --json title`
+          if [[ "$RESULT" -eq 0 ]]; then
+            echo "Creating new pull request"
+            PR_URL=`gh pr create -B master --title 'Rustc pull update' --body 'Latest update from rustc.'`
+            echo "pr_url=$PR_URL" >> $GITHUB_OUTPUT
+          else
+            PR_URL=`gh pr list --author github-actions[bot] --state open -q 'map(select(.title=="Rustc pull update")) | .[0].url' --json url,title`
+            echo "pr_url=$PR_URL" >> $GITHUB_OUTPUT
+          fi
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  send-zulip-message:
+    needs: [pull]
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Compute message
+        id: message
+        run: |
+          if [ "${{ needs.pull.result }}" == "failure" ];
+          then
+            WORKFLOW_URL="${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+            echo "message=Rustc pull sync failed. Check out the [workflow URL]($WORKFLOW_URL)." >> $GITHUB_OUTPUT
+          else
+            echo "message=Rustc pull sync succeeded. Check out the [PR](${{ needs.pull.outputs.pr_url }})." >> $GITHUB_OUTPUT
+          fi
+      - name: Send a Zulip message about updated PR
+        uses: zulip/github-actions-zulip/send-message@e4c8f27c732ba9bd98ac6be0583096dea82feea5
+        with:
+          api-key: ${{ secrets.ZULIP_API_TOKEN }}
+          email: "rustc-dev-guide-gha-notif-bot@rust-lang.zulipchat.com"
+          organization-url: "https://rust-lang.zulipchat.com"
+          to: 196385
+          type: "stream"
+          topic: "Subtree sync automation"
+          content: ${{ steps.message.outputs.message }}

.gitignore

@@ -4,3 +4,5 @@ ci/date-check/target/
 
 # Generated by check-in.sh
 pulls.json
+
+josh-sync/target

README.md

@@ -74,6 +74,13 @@ including the `<!-- toc -->` marker at the place where you want the TOC.
 
 This repository is linked to `rust-lang/rust` as a [josh](https://josh-project.github.io/josh/intro.html) subtree. You can use the following commands to synchronize the subtree in both directions.
 
+You'll need to install `josh-proxy` locally via
+
+```
+cargo +stable install josh-proxy --git https://github.com/josh-project/josh --tag r24.10.04
+```
+Older versions of `josh-proxy` may not round trip commits losslessly so it is important to install this exact version.
+
 ### Pull changes from `rust-lang/rust` into this repository
 1) Checkout a new branch that will be used to create a PR into `rust-lang/rustc-dev-guide`
 2) Run the pull command

book.toml

@@ -52,7 +52,9 @@ exclude = [
     # 500 is returned for HEAD request
     "code\\.visualstudio\\.com/docs/editor/tasks",
 ]
-cache-timeout = 86400
+# The scheduled CI runs every day and so we need to reuse a part of the cache
+# in order to face "Server returned 429 Too Many Requests" errors for github.com.
+cache-timeout = 90000
 warning-policy = "error"
 
 [output.html.redirect]

examples/rustc-driver-example.rs

@@ -15,11 +15,11 @@ extern crate rustc_span;
 
 use std::io;
 use std::path::Path;
+use std::sync::Arc;
 
 use rustc_ast_pretty::pprust::item_to_string;
-use rustc_data_structures::sync::Lrc;
-use rustc_driver::{Compilation, RunCompiler};
-use rustc_interface::interface::Compiler;
+use rustc_driver::{Compilation, run_compiler};
+use rustc_interface::interface::{Compiler, Config};
 use rustc_middle::ty::TyCtxt;
 
 struct MyFileLoader;
@@ -43,18 +43,22 @@ fn main() {
         }
     }
 
-    fn read_binary_file(&self, _path: &Path) -> io::Result<Lrc<[u8]>> {
+    fn read_binary_file(&self, _path: &Path) -> io::Result<Arc<[u8]>> {
         Err(io::Error::other("oops"))
     }
 }
 
 struct MyCallbacks;
 
 impl rustc_driver::Callbacks for MyCallbacks {
+    fn config(&mut self, config: &mut Config) {
+        config.file_loader = Some(Box::new(MyFileLoader));
+    }
+
     fn after_crate_root_parsing(
         &mut self,
         _compiler: &Compiler,
-        krate: &rustc_ast::Crate,
+        krate: &mut rustc_ast::Crate,
     ) -> Compilation {
         for item in &krate.items {
             println!("{}", item_to_string(&item));
@@ -83,10 +87,5 @@ impl rustc_driver::Callbacks for MyCallbacks {
 }
 
 fn main() {
-    match RunCompiler::new(&["main.rs".to_string()], &mut MyCallbacks) {
-        mut compiler => {
-            compiler.set_file_loader(Some(Box::new(MyFileLoader)));
-            compiler.run();
-        }
-    }
+    run_compiler(&["main.rs".to_string()], &mut MyCallbacks);
 }

examples/rustc-driver-interacting-with-the-ast.rs

@@ -15,11 +15,11 @@ extern crate rustc_span;
 
 use std::io;
 use std::path::Path;
+use std::sync::Arc;
 
 use rustc_ast_pretty::pprust::item_to_string;
-use rustc_data_structures::sync::Lrc;
-use rustc_driver::{Compilation, RunCompiler};
-use rustc_interface::interface::Compiler;
+use rustc_driver::{Compilation, run_compiler};
+use rustc_interface::interface::{Compiler, Config};
 use rustc_middle::ty::TyCtxt;
 
 struct MyFileLoader;
@@ -43,18 +43,22 @@ fn main() {
         }
     }
 
-    fn read_binary_file(&self, _path: &Path) -> io::Result<Lrc<[u8]>> {
+    fn read_binary_file(&self, _path: &Path) -> io::Result<Arc<[u8]>> {
         Err(io::Error::other("oops"))
     }
 }
 
 struct MyCallbacks;
 
 impl rustc_driver::Callbacks for MyCallbacks {
+    fn config(&mut self, config: &mut Config) {
+        config.file_loader = Some(Box::new(MyFileLoader));
+    }
+
     fn after_crate_root_parsing(
         &mut self,
         _compiler: &Compiler,
-        krate: &rustc_ast::Crate,
+        krate: &mut rustc_ast::Crate,
     ) -> Compilation {
         for item in &krate.items {
             println!("{}", item_to_string(&item));
@@ -90,10 +94,5 @@ impl rustc_driver::Callbacks for MyCallbacks {
 }
 
 fn main() {
-    match RunCompiler::new(&["main.rs".to_string()], &mut MyCallbacks) {
-        mut compiler => {
-            compiler.set_file_loader(Some(Box::new(MyFileLoader)));
-            compiler.run();
-        }
-    }
+    run_compiler(&["main.rs".to_string()], &mut MyCallbacks);
 }

examples/rustc-interface-getting-diagnostics.rs

@@ -10,15 +10,15 @@ extern crate rustc_interface;
 extern crate rustc_session;
 extern crate rustc_span;
 
+use std::sync::{Arc, Mutex};
+
 use rustc_errors::emitter::Emitter;
 use rustc_errors::registry::{self, Registry};
 use rustc_errors::translation::Translate;
 use rustc_errors::{DiagCtxt, DiagInner, FluentBundle};
 use rustc_session::config;
 use rustc_span::source_map::SourceMap;
 
-use std::sync::{Arc, Mutex};
-
 struct DebugEmitter {
     source_map: Arc<SourceMap>,
     diagnostics: Arc<Mutex<Vec<DiagInner>>>,
@@ -67,10 +67,10 @@ fn main() {
         locale_resources: rustc_driver::DEFAULT_LOCALE_RESOURCES.to_owned(),
         lint_caps: rustc_hash::FxHashMap::default(),
         psess_created: Some(Box::new(|parse_sess| {
-            parse_sess.set_dcx(DiagCtxt::new(Box::new(DebugEmitter {
+            parse_sess.dcx().set_emitter(Box::new(DebugEmitter {
                 source_map: parse_sess.clone_source_map(),
                 diagnostics,
-            })));
+            }));
         })),
         register_lints: None,
         override_queries: None,

josh-sync/src/sync.rs

@@ -45,6 +45,11 @@ impl GitSync {
         let josh_url =
             format!("http://localhost:{JOSH_PORT}/{UPSTREAM_REPO}.git@{commit}{JOSH_FILTER}.git");
 
+        let previous_base_commit = sh.read_file("rust-version")?.trim().to_string();
+        if previous_base_commit == commit {
+            return Err(anyhow::anyhow!("No changes since last pull"));
+        }
+
         // Update rust-version file. As a separate commit, since making it part of
         // the merge has confused the heck out of josh in the past.
         // We pass `--no-verify` to avoid running git hooks.
@@ -76,12 +81,22 @@ impl GitSync {
         };
         let num_roots_before = num_roots()?;
 
+        let sha = cmd!(sh, "git rev-parse HEAD").output().context("FAILED to get current commit")?.stdout;
+
         // Merge the fetched commit.
         const MERGE_COMMIT_MESSAGE: &str = "Merge from rustc";
         cmd!(sh, "git merge FETCH_HEAD --no-verify --no-ff -m {MERGE_COMMIT_MESSAGE}")
             .run()
             .context("FAILED to merge new commits, something went wrong")?;
 
+        let current_sha = cmd!(sh, "git rev-parse HEAD").output().context("FAILED to get current commit")?.stdout;
+        if current_sha == sha {
+            cmd!(sh, "git reset --hard HEAD^")
+                .run()
+                .expect("FAILED to clean up after creating the preparation commit");
+            return Err(anyhow::anyhow!("No merge was performed, nothing to pull. Rolled back the preparation commit."));
+        }
+
         // Check that the number of roots did not increase.
         if num_roots()? != num_roots_before {
             bail!("Josh created a new root commit. This is probably not the history you want.");

rust-version

@@ -1 +1 @@
-dcfa38fe234de9304169afc6638e81d0dd222c06
+66d6064f9eb888018775e08f84747ee6f39ba28e

src/about-this-guide.md

@@ -72,7 +72,6 @@ You might also find the following sites useful:
 - The [Rust reference][rr], even though it doesn't specifically talk about
   Rust's internals, is a great resource nonetheless
 - Although out of date, [Tom Lee's great blog article][tlgba] is very helpful
-- [rustaceans.org][ro] is helpful, but mostly dedicated to IRC
 - The [Rust Compiler Testing Docs][rctd]
 - For [@bors], [this cheat sheet][cheatsheet] is helpful
 - Google is always helpful when programming.

src/appendix/code-index.md

@@ -14,17 +14,16 @@ Item            |  Kind    | Short description           | Chapter            |
 `Diag` | struct | A struct for a compiler diagnostic, such as an error or lint | [Emitting Diagnostics] | [compiler/rustc_errors/src/diagnostic.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_errors/struct.Diag.html)
 `DocContext` | struct | A state container used by rustdoc when crawling through a crate to gather its documentation | [Rustdoc] | [src/librustdoc/core.rs](https://github.com/rust-lang/rust/blob/master/src/librustdoc/core.rs)
 `HirId` | struct | One of four types of HIR node identifiers | [Identifiers in the HIR] | [compiler/rustc_hir/src/hir_id.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir_id/struct.HirId.html)
+`Lexer` | struct | This is the lexer used during parsing. It consumes characters from the raw source code being compiled and produces a series of tokens for use by the rest of the parser | [The parser] |  [compiler/rustc_parse/src/lexer/mod.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse/lexer/struct.Lexer.html)
 `NodeId` | struct | One of four types of HIR node identifiers. Being phased out | [Identifiers in the HIR] | [compiler/rustc_ast/src/ast.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/node_id/struct.NodeId.html)
 `P` | struct | An owned immutable smart pointer. By contrast, `&T` is not owned, and `Box<T>` is not immutable. | None | [compiler/rustc_ast/src/ptr.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ptr/struct.P.html)
 `ParamEnv` | struct | Information about generic parameters or `Self`, useful for working with associated or generic items | [Parameter Environment] | [compiler/rustc_middle/src/ty/mod.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.ParamEnv.html)
 `ParseSess` | struct | This struct contains information about a parsing session | [The parser] | [compiler/rustc_session/src/parse/parse.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_session/parse/struct.ParseSess.html)
-`Query` | struct | Represents the result of query to the `Compiler` interface and allows stealing, borrowing, and returning the results of compiler passes. | [The Rustc Driver and Interface] | [compiler/rustc_interface/src/queries.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_interface/queries/struct.Query.html)
 `Rib` | struct | Represents a single scope of names | [Name resolution] | [compiler/rustc_resolve/src/lib.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_resolve/late/struct.Rib.html)
 `Session` | struct | The data associated with a compilation session | [The parser], [The Rustc Driver and Interface] | [compiler/rustc_session/src/session.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_session/struct.Session.html)
 `SourceFile` | struct | Part of the `SourceMap`. Maps AST nodes to their source code for a single source file. Was previously called FileMap | [The parser] | [compiler/rustc_span/src/lib.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.SourceFile.html)
 `SourceMap` | struct | Maps AST nodes to their source code. It is composed of `SourceFile`s. Was previously called CodeMap | [The parser] | [compiler/rustc_span/src/source_map.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/source_map/struct.SourceMap.html)
 `Span` | struct  | A location in the user's source code, used for error reporting primarily | [Emitting Diagnostics] | [compiler/rustc_span/src/span_encoding.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html)
-`StringReader` | struct | This is the lexer used during parsing. It consumes characters from the raw source code being compiled and produces a series of tokens for use by the rest of the parser | [The parser] |  [compiler/rustc_parse/src/lexer/mod.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse/lexer/struct.StringReader.html)
 `rustc_ast::token_stream::TokenStream` | struct | An abstract sequence of tokens, organized into `TokenTree`s | [The parser], [Macro expansion] | [compiler/rustc_ast/src/tokenstream.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/tokenstream/struct.TokenStream.html)
 `TraitDef` | struct | This struct contains a trait's definition with type information | [The `ty` modules] |  [compiler/rustc_middle/src/ty/trait_def.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/trait_def/struct.TraitDef.html)
 `TraitRef` | struct | The combination of a trait and its input types (e.g. `P0: Trait<P1...Pn>`) | [Trait Solving: Goals and Clauses]  |  [compiler/rustc_middle/src/ty/sty.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/type.TraitRef.html)

src/appendix/glossary.md

@@ -69,7 +69,7 @@ Term                                                  | Meaning
 <span id="rib">rib</span>                      |  A data structure in the name resolver that keeps track of a single scope for names. ([see more](../name-resolution.md))
 <span id="rpit">RPIT</span>                    |  A return-position `impl Trait`. ([see the reference](https://doc.rust-lang.org/reference/types/impl-trait.html#abstract-return-types)).
 <span id="rpitit">RPITIT</span>                |  A return-position `impl Trait` in trait. Unlike RPIT, this is desugared to a generic associated type (GAT). Introduced in [RFC 3425](https://rust-lang.github.io/rfcs/3425-return-position-impl-trait-in-traits.html). ([see more](../return-position-impl-trait-in-trait.md))
-<span id="scrutinee">scrutinee</div>           |  A scrutinee is the expression that is matched on in `match` expressions and similar pattern matching constructs. For example, in `match x { A => 1, B => 2 }`, the expression `x` is the scrutinee.
+<span id="scrutinee">scrutinee</span>          |  A scrutinee is the expression that is matched on in `match` expressions and similar pattern matching constructs. For example, in `match x { A => 1, B => 2 }`, the expression `x` is the scrutinee.
 <span id="sess">`sess`</span>                  |  The compiler _session_, which stores global data used throughout compilation
 <span id="side-tables">side tables</span>      |  Because the [AST](#ast) and HIR are immutable once created, we often carry extra information about them in the form of hashtables, indexed by the id of a particular node.
 <span id="sigil">sigil</span>                  |  Like a keyword but composed entirely of non-alphanumeric tokens. For example, `&` is a sigil for references.

src/backend/backend-agnostic.md

@@ -45,7 +45,7 @@ heavily on other parts of the crate. The separation of the code must not affect
 the logic of the code nor its performance.
 
 For these reasons, the separation process involves two transformations that
-have to be done at the same time for the resulting code to compile :
+have to be done at the same time for the resulting code to compile:
 
 1. replace all the LLVM-specific types by generics inside function signatures
    and structure definitions;

src/backend/libs-and-metadata.md

@@ -42,7 +42,7 @@ format is specific to `rustc`, and may change over time. This file contains:
 ### dylib
 
 A `dylib` is a platform-specific shared library. It includes the `rustc`
-[metadata] in a special link section called `.rustc` in a compressed format.
+[metadata] in a special link section called `.rustc`.
 
 ### rmeta