Merge ref 'caccb4d0368b' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: caccb4d0368bd918ef6668af8e13834d07040417
Filtered ref: 0f345ed05d559bbfb754f1403b16199366cda2e0
Upstream diff: rust-lang/rust@21a19c2...caccb4d

This merge was created using https://github.com/rust-lang/josh-sync.

Author: The rustc-josh-sync Cronjob Bot

.github/workflows/ci.yml

@@ -31,16 +31,22 @@ jobs:
             os: ubuntu-24.04-arm
             multiarch: armhf
             gcc_cross: arm-linux-gnueabihf
-          - host_target: riscv64gc-unknown-linux-gnu
-            os: ubuntu-latest
-            multiarch: riscv64
-            gcc_cross: riscv64-linux-gnu
-            qemu: true
-          - host_target: s390x-unknown-linux-gnu
-            os: ubuntu-latest
-            multiarch: s390x
-            gcc_cross: s390x-linux-gnu
-            qemu: true
+          # Disabled due to Ubuntu repo trouble
+          # - host_target: riscv64gc-unknown-linux-gnu
+          #   os: ubuntu-latest
+          #   multiarch: riscv64
+          #   gcc_cross: riscv64-linux-gnu
+          #   qemu: true
+          # - host_target: s390x-unknown-linux-gnu
+          #   os: ubuntu-latest
+          #   multiarch: s390x
+          #   gcc_cross: s390x-linux-gnu
+          #   qemu: true
+          # - host_target: powerpc64le-unknown-linux-gnu
+          #   os: ubuntu-latest
+          #   multiarch: ppc64el
+          #   gcc_cross: powerpc64le-linux-gnu
+          #   qemu: true
           - host_target: aarch64-apple-darwin
             os: macos-latest
           - host_target: i686-pc-windows-msvc
@@ -62,19 +68,13 @@ jobs:
       - name: install multiarch
         if: ${{ matrix.multiarch != '' }}
         run: |
-          # s390x, ppc64el need Ubuntu Ports to be in the mirror list
+          # s390x, ppc64el, riscv64 need Ubuntu Ports to be in the mirror list
           sudo bash -c "echo 'https://ports.ubuntu.com/	priority:4' >> /etc/apt/apt-mirrors.txt"
           # Add architecture
           sudo dpkg --add-architecture ${{ matrix.multiarch }}
           sudo apt update
           # Install needed packages
           sudo apt install $(echo "libatomic1: zlib1g-dev:" | sed 's/:/:${{ matrix.multiarch }}/g')
-      - name: Install rustup on Windows ARM
-        if: ${{ matrix.os == 'windows-11-arm' }}
-        run: |
-            curl -LOs https://static.rust-lang.org/rustup/dist/aarch64-pc-windows-msvc/rustup-init.exe
-            ./rustup-init.exe -y --no-modify-path
-            echo "$USERPROFILE/.cargo/bin" >> "$GITHUB_PATH"
       - uses: ./.github/workflows/setup
         with:
           toolchain_flags: "--host ${{ matrix.host_target }}"
@@ -117,6 +117,41 @@ jobs:
       - name: rustdoc
         run: RUSTDOCFLAGS="-Dwarnings" ./miri doc --document-private-items
 
+  bootstrap:
+    name: bootstrap build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      # Deliberately skipping `./.github/workflows/setup` as we do our own setup
+      - name: Add cache for cargo
+        id: cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            # Taken from <https://doc.rust-lang.org/nightly/cargo/guide/cargo-home.html#caching-the-cargo-home-in-ci>.
+            # Cache package/registry information
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git/db
+            # Cache bootstrap downloads
+            ../rust/build/cache
+          key: cargo-bootstrap-${{ hashFiles('rust-version') }}
+          restore-keys: cargo-bootstrap
+      - name: prepare build environment
+        run: |
+          MIRIDIR=$(pwd)
+          cd ..
+          # Bootstrap needs at least depth 2 to function.
+          git clone https://github.com/rust-lang/rust/ rust --depth 2 --revision $(cat "$MIRIDIR/rust-version")
+          cd rust
+          # Replace the in-tree Miri with the current version.
+          rm src/tools/miri -rf
+          ln -s "$MIRIDIR" src/tools/miri
+      - name: check build
+        run: |
+          cd ../rust # ./x does not seem to like being invoked from elsewhere
+          ./x check miri
+
   coverage:
     name: coverage report
     runs-on: ubuntu-latest
@@ -130,7 +165,7 @@ jobs:
   # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
   # And they should be added below in `cron-fail-notify` as well.
   conclusion:
-    needs: [test, style, coverage]
+    needs: [test, style, bootstrap, coverage]
     # We need to ensure this job does *not* get skipped if its dependencies fail,
     # because a skipped job is considered a success by GitHub. So we have to
     # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
@@ -169,7 +204,13 @@ jobs:
         run: rustup toolchain install nightly --profile minimal
       - name: Install rustup-toolchain-install-master
         run: cargo install -f rustup-toolchain-install-master
-      - name: Push changes to a branch and create PR
+      # Create a token for the next step so it can create a PR that actually runs CI.
+      - uses: actions/create-github-app-token@v2
+        id: app-token
+        with:
+          app-id: ${{ vars.APP_CLIENT_ID }}
+          private-key: ${{ secrets.APP_PRIVATE_KEY }}
+      - name: pull changes from rustc and create PR
         run: |
           # Make it easier to see what happens.
           set -x
@@ -198,14 +239,14 @@ jobs:
           BRANCH="rustup-$(date -u +%Y-%m-%d)"
           git switch -c $BRANCH
           git push -u origin $BRANCH
-          gh pr create -B master --title 'Automatic Rustup' --body 'Please close and re-open this PR to trigger CI, then enable auto-merge.'
+          gh pr create -B master --title 'Automatic Rustup' --body "Update \`rustc\` to https://github.com/rust-lang/rust/commit/$(cat rust-version)."
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ steps.app-token.outputs.token }}
 
   cron-fail-notify:
     name: cronjob failure notification
     runs-on: ubuntu-latest
-    needs: [test, style, coverage]
+    needs: [test, style, bootstrap, coverage]
     if: ${{ github.event_name == 'schedule' && failure() }}
     steps:
       # Send a Zulip notification

CONTRIBUTING.md

@@ -255,6 +255,12 @@ when installing the Miri toolchain. Alternatively, set the `RUSTUP_TOOLCHAIN` en
 
 [`etc/rust_analyzer_helix.toml`]: https://github.com/rust-lang/miri/blob/master/etc/rust_analyzer_helix.toml
 
+### Zed
+
+Copy [`etc/rust_analyzer_zed.json`] to `.zed/settings.json` in the project root directory.
+
+[`etc/rust_analyzer_zed.json`]: https://github.com/rust-lang/miri/blob/master/etc/rust_analyzer_zed.json
+
 ### Advanced configuration
 
 If you are building Miri with a locally built rustc, set

Cargo.lock

@@ -39,7 +39,7 @@ features = ['unprefixed_malloc_on_supported_platforms']
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
 # native-lib dependencies
-libffi = { version = "4.0.0", optional = true }
+libffi = { version = "4.1.1", optional = true }
 libloading = { version = "0.8", optional = true }
 serde = { version = "1.0.219", features = ["derive"], optional = true }
 
@@ -70,14 +70,15 @@ harness = false
 
 [features]
 default = ["stack-cache", "native-lib"]
-genmc = ["dep:genmc-sys"] # this enables a GPL dependency!
+genmc = ["dep:genmc-sys"]
 stack-cache = []
 stack-cache-consistency-check = ["stack-cache"]
 tracing = ["serde_json"]
 native-lib = ["dep:libffi", "dep:libloading", "dep:capstone", "dep:ipc-channel", "dep:nix", "dep:serde"]
 
 [lints.rust.unexpected_cfgs]
 level = "warn"
+check-cfg = ['cfg(bootstrap)']
 
 # Be aware that this file is inside a workspace when used via the
 # submodule in the rustc repo. That means there are many cargo features

Cargo.toml

@@ -220,7 +220,7 @@ degree documented below):
   - `solaris` / `illumos`: maintained by @devnexen. Supports the entire test suite.
   - `freebsd`: maintained by @YohDeadfall and @LorrensP-2158466. Supports the entire test suite.
   - `android`: **maintainer wanted**. Support very incomplete, but a basic "hello world" works.
-  - `wasi`: **maintainer wanted**. Support very incomplete, not even standard output works, but an empty `main` function works.
+  - `wasi`: **maintainer wanted**. Support very incomplete, but a basic "hello world" works.
 - For targets on other operating systems, Miri might fail before even reaching the `main` function.
 
 However, even for targets that we do support, the degree of support for accessing platform APIs
@@ -319,8 +319,14 @@ environment variable. We first document the most relevant and most commonly used
   Can be used without a value; in that case the range defaults to `0..64`.
 * `-Zmiri-many-seeds-keep-going` tells Miri to really try all the seeds in the given range, even if
   a failing seed has already been found. This is useful to determine which fraction of seeds fails.
+* `-Zmiri-max-extra-rounding-error` tells Miri to always apply the maximum error to float operations
+  that do not have a guaranteed precision. The sign of the error is still non-deterministic.
 * `-Zmiri-no-extra-rounding-error` stops Miri from adding extra rounding errors to float operations
   that do not have a guaranteed precision.
+* `-Zmiri-no-short-fd-operations` stops Miri from artificially forcing `read`/`write` operations
+  to only process a part of their buffer. Note that whenever Miri uses host operations to
+  implement `read`/`write` (e.g. for file-backed file descriptors), the host system can still
+  introduce short reads/writes.
 * `-Zmiri-num-cpus` states the number of available CPUs to be reported by miri. By default, the
   number of available CPUs is `1`. Note that this flag does not affect how miri handles threads in
   any way.
@@ -600,6 +606,7 @@ Definite bugs found:
 * [A bug in the new `RwLock::downgrade` implementation](https://rust-lang.zulipchat.com/#narrow/channel/269128-miri/topic/Miri.20error.20library.20test) (caught by Miri before it landed in the Rust repo)
 * [Mockall reading uninitialized memory when mocking `std::io::Read::read`, even if all expectations are satisfied](https://github.com/asomers/mockall/issues/647) (caught by Miri running Tokio's test suite)
 * [`ReentrantLock` not correctly dealing with reuse of addresses for TLS storage of different threads](https://github.com/rust-lang/rust/pull/141248)
+* [Rare Deadlock in the thread (un)parking example code](https://github.com/rust-lang/rust/issues/145816)
 
 Violations of [Stacked Borrows] found that are likely bugs (but Stacked Borrows is currently just an experiment):
 

README.md

@@ -18,7 +18,7 @@ directories = "6"
 rustc_version = "0.4"
 serde_json = "1.0.40"
 cargo_metadata = "0.21"
-rustc-build-sysroot = "0.5.8"
+rustc-build-sysroot = "0.5.10"
 
 # Enable some feature flags that dev-dependencies need but dependencies
 # do not.  This makes `./miri install` after `./miri build` faster.

cargo-miri/Cargo.lock

@@ -65,16 +65,6 @@ fn forward_patched_extern_arg(args: &mut impl Iterator<Item = String>, cmd: &mut
 }
 
 pub fn phase_cargo_miri(mut args: impl Iterator<Item = String>) {
-    // Check for version and help flags even when invoked as `cargo-miri`.
-    if has_arg_flag("--help") || has_arg_flag("-h") {
-        show_help();
-        return;
-    }
-    if has_arg_flag("--version") || has_arg_flag("-V") {
-        show_version();
-        return;
-    }
-
     // Require a subcommand before any flags.
     // We cannot know which of those flags take arguments and which do not,
     // so we cannot detect subcommands later.
@@ -85,11 +75,36 @@ pub fn phase_cargo_miri(mut args: impl Iterator<Item = String>) {
         "setup" => MiriCommand::Setup,
         "test" | "t" | "run" | "r" | "nextest" => MiriCommand::Forward(subcommand),
         "clean" => MiriCommand::Clean,
-        _ =>
+        _ => {
+            // Check for version and help flags.
+            if has_arg_flag("--help") || has_arg_flag("-h") {
+                show_help();
+                return;
+            }
+            if has_arg_flag("--version") || has_arg_flag("-V") {
+                show_version();
+                return;
+            }
             show_error!(
                 "`cargo miri` supports the following subcommands: `run`, `test`, `nextest`, `clean`, and `setup`."
-            ),
+            )
+        }
     };
+    if has_arg_flag("--help") || has_arg_flag("-h") {
+        match subcommand {
+            MiriCommand::Forward(verb) => {
+                println!("`cargo miri {verb}` supports the same flags as `cargo {verb}`:\n");
+                let mut cmd = cargo();
+                cmd.arg(verb);
+                cmd.arg("--help");
+                exec(cmd);
+            }
+            _ => {
+                show_help();
+                return;
+            }
+        }
+    }
     let verbose = num_arg_flag("-v") + num_arg_flag("--verbose");
     let quiet = has_arg_flag("-q") || has_arg_flag("--quiet");