Auto merge of #146156 - RalfJung:miri, r=RalfJung

miri subtree update

Subtree update of `miri` to 883dbf0.

Created using https://github.com/rust-lang/josh-sync.

r? `@ghost`

Author: bors

.github/workflows/ci.yml

@@ -41,6 +41,11 @@ jobs:
             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

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 }
 

Cargo.toml

@@ -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.

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");