Auto merge of #104617 - RalfJung:miri, r=RalfJung

update Miri

r? `@thomcc` for the lib changes (removing a `cfg(miri)` that is no longer needed)

Cargo.lock

@@ -2330,7 +2330,6 @@ dependencies = [
  "regex",
  "rustc-workspace-hack",
  "rustc_version",
- "shell-escape",
  "smallvec",
  "ui_test",
 ]

library/std/src/sys/unix/time.rs

@@ -150,7 +150,7 @@ impl From<libc::timespec> for Timespec {
 }
 
 #[cfg(any(
-    all(target_os = "macos", any(not(target_arch = "aarch64"), miri)),
+    all(target_os = "macos", any(not(target_arch = "aarch64"))),
     target_os = "ios",
     target_os = "watchos"
 ))]
@@ -270,7 +270,7 @@ mod inner {
 }
 
 #[cfg(not(any(
-    all(target_os = "macos", any(not(target_arch = "aarch64"), miri)),
+    all(target_os = "macos", any(not(target_arch = "aarch64"))),
     target_os = "ios",
     target_os = "watchos"
 )))]

src/tools/miri/Cargo.lock

@@ -383,7 +383,6 @@ dependencies = [
  "regex",
  "rustc-workspace-hack",
  "rustc_version",
- "shell-escape",
  "smallvec",
  "ui_test",
 ]
@@ -632,12 +631,6 @@ dependencies = [
  "lazy_static",
 ]
 
-[[package]]
-name = "shell-escape"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45bb67a18fa91266cc7807181f62f9178a6873bfad7dc788c42e6430db40184f"
-
 [[package]]
 name = "smallvec"
 version = "1.9.0"

src/tools/miri/Cargo.toml

@@ -21,7 +21,6 @@ doctest = false # and no doc tests
 getrandom = { version = "0.2", features = ["std"] }
 env_logger = "0.9"
 log = "0.4"
-shell-escape = "0.1.4"
 rand = "0.8"
 smallvec = "1.7"
 

src/tools/miri/README.md

@@ -1,10 +1,5 @@
 # Miri
 
-[![Actions build status][actions-badge]][actions-url]
-
-[actions-badge]: https://github.com/rust-lang/miri/workflows/CI/badge.svg?branch=master
-[actions-url]: https://github.com/rust-lang/miri/actions
-
 An experimental interpreter for [Rust][rust]'s
 [mid-level intermediate representation][mir] (MIR). It can run binaries and
 test suites of cargo projects and detect certain classes of
@@ -200,7 +195,7 @@ randomness that is used to determine allocation base addresses. The following
 snippet calls Miri in a loop with different values for the seed:
 
 ```
-for SEED in $({ echo obase=16; seq 0 255; } | bc); do
+for SEED in $(seq 0 255); do
   echo "Trying seed: $SEED"
   MIRIFLAGS=-Zmiri-seed=$SEED cargo miri test || { echo "Failing seed: $SEED"; break; };
 done
@@ -308,7 +303,7 @@ environment variable. We first document the most relevant and most commonly used
   tell what it is doing when a program just keeps running. You can customize how frequently the
   report is printed via `-Zmiri-report-progress=<blocks>`, which prints the report every N basic
   blocks.
-* `-Zmiri-seed=<hex>` configures the seed of the RNG that Miri uses to resolve non-determinism. This
+* `-Zmiri-seed=<num>` configures the seed of the RNG that Miri uses to resolve non-determinism. This
   RNG is used to pick base addresses for allocations, to determine preemption and failure of
   `compare_exchange_weak`, and to control store buffering for weak memory emulation. When isolation
   is enabled (the default), this is also used to emulate system entropy. The default seed is 0. You

src/tools/miri/miri

@@ -48,10 +48,10 @@ Update and activate the rustup toolchain 'miri' to the commit given in the
 `rustup-toolchain-install-master` must be installed for this to work. Any extra
 flags are passed to `rustup-toolchain-install-master`.
 
-./miri rustc-pull:
-Pull and merge Miri changes from the rustc repo. The fetched commit is stored in
-the `rust-version` file, so the next `./miri toolchain` will install the rustc
-we just pulled.
+./miri rustc-pull <commit>:
+Pull and merge Miri changes from the rustc repo. Defaults to fetching the latest
+rustc commit. The fetched commit is stored in the `rust-version` file, so the
+next `./miri toolchain` will install the rustc that just got pulled.
 
 ./miri rustc-push <github user> <branch>:
 Push Miri changes back to the rustc repo. This will pull a copy of the rustc
@@ -113,18 +113,17 @@ toolchain)
     ;;
 rustc-pull)
     cd "$MIRIDIR"
-    FETCH_COMMIT=$(git ls-remote https://github.com/rust-lang/rust/ HEAD | cut -f 1)
-    # We can't pull from a commit with josh
-    # (https://github.com/josh-project/josh/issues/1034), so we just hope that
-    # nothing gets merged into rustc *during* this pull.
-    git fetch http://localhost:8000/rust-lang/rust.git$JOSH_FILTER.git master
-    # Just verify that `master` didn't move.
-    if [[ $FETCH_COMMIT != $(git ls-remote https://github.com/rust-lang/rust/ HEAD | cut -f 1) ]]; then
-        echo "Looks like something got merged into Rust *while we were pulling*. Aborting. Please try again."
+    FETCH_COMMIT="$1"
+    if [ -z "$FETCH_COMMIT" ]; then
+        FETCH_COMMIT=$(git ls-remote https://github.com/rust-lang/rust/ HEAD | cut -f 1)
     fi
-    echo "$FETCH_COMMIT" > rust-version # do this *before* merging as merging will fail in case of conflicts
+    # 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.
+    echo "$FETCH_COMMIT" > rust-version
+    git commit rust-version -m "Preparing for merge from rustc"
+    # Fetch given rustc commit and note down which one that was
+    git fetch http://localhost:8000/rust-lang/rust.git@$FETCH_COMMIT$JOSH_FILTER.git
     git merge FETCH_HEAD --no-ff -m "Merge from rustc"
-    git commit rust-version --amend -m "Merge from rustc"
     exit 0
     ;;
 rustc-push)
@@ -157,16 +156,27 @@ rustc-push)
     fi
     git fetch https://github.com/rust-lang/rust $BASE
     git push https://github.com/$USER/rust $BASE:refs/heads/$BRANCH -f
+    echo
     # Do the actual push.
     cd "$MIRIDIR"
     echo "Pushing Miri changes..."
     git push http://localhost:8000/$USER/rust.git$JOSH_FILTER.git HEAD:$BRANCH
-    exit 0
+    # Do a round-trip check to make sure the push worked as expected.
+    echo
+    git fetch http://localhost:8000/$USER/rust.git@$JOSH_FILTER.git $BRANCH &>/dev/null
+    if [[ $(git rev-parse HEAD) != $(git rev-parse FETCH_HEAD) ]]; then
+        echo "ERROR: Josh created a non-roundtrip push! Do NOT merge this into rustc!"
+        exit 1
+    else
+        echo "Confirmed that the push round-trips back to Miri properly. Please create a rustc PR:"
+        echo "    https://github.com/$USER/rust/pull/new/$BRANCH"
+        exit 0
+    fi
     ;;
 many-seeds)
-    for SEED in $({ echo obase=16; seq 0 255; } | bc); do
+    for SEED in $(seq 0 255); do
         echo "Trying seed: $SEED"
-        MIRIFLAGS="$MIRIFLAGS -Zmiri-seed=$SEED" $@ || { echo "Failing seed: $SEED"; break; }
+        MIRIFLAGS="$MIRIFLAGS -Zlayout-seed=$SEED -Zmiri-seed=$SEED" $@ || { echo "Failing seed: $SEED"; break; }
     done
     exit 0
     ;;

src/tools/miri/rust-version

@@ -1 +1 @@
-101e1822c3e54e63996c8aaa014d55716f3937eb
+7477c1f4f7d6bef037d523099b240d22aa1b63a0

src/tools/miri/src/bin/miri.rs

@@ -394,10 +394,9 @@ fn main() {
             if miri_config.seed.is_some() {
                 show_error!("Cannot specify -Zmiri-seed multiple times!");
             }
-            let seed = u64::from_str_radix(param, 16)
-                        .unwrap_or_else(|_| show_error!(
-                            "-Zmiri-seed should only contain valid hex digits [0-9a-fA-F] and must fit into a u64 (max 16 characters)"
-                        ));
+            let seed = param.parse::<u64>().unwrap_or_else(|_| {
+                show_error!("-Zmiri-seed must be an integer that fits into u64")
+            });
             miri_config.seed = Some(seed);
         } else if let Some(_param) = arg.strip_prefix("-Zmiri-env-exclude=") {
             show_error!(

src/tools/miri/src/shims/mod.rs

@@ -89,6 +89,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         }
 
         let ptr = this.read_pointer(ptr_op)?;
+        // If this carries no provenance, treat it like an integer.
+        if ptr.provenance.is_none() {
+            // Use actual implementation.
+            return Ok(false);
+        }
+
         if let Ok((alloc_id, _offset, _)) = this.ptr_try_get_alloc_id(ptr) {
             // Only do anything if we can identify the allocation this goes to.
             let (_size, cur_align, _kind) = this.get_alloc_info(alloc_id);

src/tools/miri/src/shims/time.rs

@@ -22,28 +22,52 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         let this = self.eval_context_mut();
 
-        this.assert_target_os("linux", "clock_gettime");
+        this.assert_target_os_is_unix("clock_gettime");
 
         let clk_id = this.read_scalar(clk_id_op)?.to_i32()?;
 
-        // Linux has two main kinds of clocks. REALTIME clocks return the actual time since the
-        // Unix epoch, including effects which may cause time to move backwards such as NTP.
-        // Linux further distinguishes regular and "coarse" clocks, but the "coarse" version
-        // is just specified to be "faster and less precise", so we implement both the same way.
-        let absolute_clocks =
-            [this.eval_libc_i32("CLOCK_REALTIME")?, this.eval_libc_i32("CLOCK_REALTIME_COARSE")?];
-        // The second kind is MONOTONIC clocks for which 0 is an arbitrary time point, but they are
-        // never allowed to go backwards. We don't need to do any additonal monotonicity
-        // enforcement because std::time::Instant already guarantees that it is monotonic.
-        let relative_clocks =
-            [this.eval_libc_i32("CLOCK_MONOTONIC")?, this.eval_libc_i32("CLOCK_MONOTONIC_COARSE")?];
+        let absolute_clocks;
+        let mut relative_clocks;
+
+        match this.tcx.sess.target.os.as_ref() {
+            "linux" => {
+                // Linux has two main kinds of clocks. REALTIME clocks return the actual time since the
+                // Unix epoch, including effects which may cause time to move backwards such as NTP.
+                // Linux further distinguishes regular and "coarse" clocks, but the "coarse" version
+                // is just specified to be "faster and less precise", so we implement both the same way.
+                absolute_clocks = vec![
+                    this.eval_libc_i32("CLOCK_REALTIME")?,
+                    this.eval_libc_i32("CLOCK_REALTIME_COARSE")?,
+                ];
+                // The second kind is MONOTONIC clocks for which 0 is an arbitrary time point, but they are
+                // never allowed to go backwards. We don't need to do any additonal monotonicity
+                // enforcement because std::time::Instant already guarantees that it is monotonic.
+                relative_clocks = vec![
+                    this.eval_libc_i32("CLOCK_MONOTONIC")?,
+                    this.eval_libc_i32("CLOCK_MONOTONIC_COARSE")?,
+                ];
+            }
+            "macos" => {
+                absolute_clocks = vec![this.eval_libc_i32("CLOCK_REALTIME")?];
+                relative_clocks = vec![this.eval_libc_i32("CLOCK_MONOTONIC")?];
+                // Some clocks only seem to exist in the aarch64 version of the target.
+                if this.tcx.sess.target.arch == "aarch64" {
+                    // `CLOCK_UPTIME_RAW` supposed to not increment while the system is asleep... but
+                    // that's not really something a program running inside Miri can tell, anyway.
+                    // We need to support it because std uses it.
+                    relative_clocks.push(this.eval_libc_i32("CLOCK_UPTIME_RAW")?);
+                }
+            }
+            target => throw_unsup_format!("`clock_gettime` is not supported on target OS {target}"),
+        }
 
         let duration = if absolute_clocks.contains(&clk_id) {
             this.check_no_isolation("`clock_gettime` with `REALTIME` clocks")?;
             system_time_to_duration(&SystemTime::now())?
         } else if relative_clocks.contains(&clk_id) {
             this.machine.clock.now().duration_since(this.machine.clock.anchor())
         } else {
+            // Unsupported clock.
             let einval = this.eval_libc("EINVAL")?;
             this.set_last_error(einval)?;
             return Ok(Scalar::from_i32(-1));

src/tools/miri/src/shims/unix/foreign_items.rs

@@ -180,6 +180,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 let result = this.gettimeofday(tv, tz)?;
                 this.write_scalar(Scalar::from_i32(result), dest)?;
             }
+            "clock_gettime" => {
+                let [clk_id, tp] =
+                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let result = this.clock_gettime(clk_id, tp)?;
+                this.write_scalar(result, dest)?;
+            }
 
             // Allocation
             "posix_memalign" => {

src/tools/miri/src/shims/unix/linux/foreign_items.rs

@@ -43,15 +43,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.write_scalar(result, dest)?;
             }
 
-            // Time related shims
-            "clock_gettime" => {
-                // This is a POSIX function but it has only been tested on linux.
-                let [clk_id, tp] =
-                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                let result = this.clock_gettime(clk_id, tp)?;
-                this.write_scalar(result, dest)?;
-            }
-
             // Threading
             "pthread_condattr_setclock" => {
                 let [attr, clock_id] =