Auto merge of #119039 - RalfJung:miri, r=RalfJung

Miri subtree update

r? `@ghost`

src/tools/miri/CONTRIBUTING.md

@@ -109,7 +109,7 @@ to run the other checks while ignoring the ui output, use `MIRI_SKIP_UI_CHECKS=1
 
 For more info on how to configure ui tests see [the documentation on the ui test crate][ui_test]
 
-[ui_test]: ui_test/README.md
+[ui_test]: https://github.com/oli-obk/ui_test/blob/main/README.md
 
 ### Testing `cargo miri`
 

src/tools/miri/cargo-miri/src/util.rs

@@ -200,9 +200,6 @@ pub fn ask_to_run(mut cmd: Command, ask: bool, text: &str) {
 // cargo invocation.
 fn cargo_extra_flags() -> Vec<String> {
     let mut flags = Vec::new();
-    // `-Zunstable-options` is required by `--config`.
-    flags.push("-Zunstable-options".to_string());
-
     // Forward `--config` flags.
     let config_flag = "--config";
     for arg in get_arg_flag_values(config_flag) {

src/tools/miri/miri

@@ -2,5 +2,6 @@
 set -e
 # Instead of doing just `cargo run --manifest-path .. $@`, we invoke miri-script binary directly. Invoking `cargo run` goes through
 # rustup (that sets it's own environmental variables), which is undesirable.
-cargo build $CARGO_EXTRA_FLAGS -q --manifest-path "$(dirname "$0")"/miri-script/Cargo.toml
-"$(dirname "$0")"/miri-script/target/debug/miri-script "$@"
+MIRI_SCRIPT_TARGET_DIR="$(dirname "$0")"/miri-script/target
+cargo build $CARGO_EXTRA_FLAGS -q --target-dir "$MIRI_SCRIPT_TARGET_DIR" --manifest-path "$(dirname "$0")"/miri-script/Cargo.toml
+"$MIRI_SCRIPT_TARGET_DIR"/debug/miri-script "$@"

src/tools/miri/miri-script/src/util.rs

@@ -73,7 +73,9 @@ impl MiriEnv {
             flags.push("-C link-args=-Wl,-rpath,");
             flags.push(libdir);
             // Enable rustc-specific lints (ignored without `-Zunstable-options`).
-            flags.push(" -Zunstable-options -Wrustc::internal -Wrust_2018_idioms -Wunused_lifetimes -Wsemicolon_in_expressions_from_macros");
+            flags.push(
+                " -Zunstable-options -Wrustc::internal -Wrust_2018_idioms -Wunused_lifetimes",
+            );
             // Add user-defined flags.
             if let Some(value) = std::env::var_os("RUSTFLAGS") {
                 flags.push(" ");

src/tools/miri/rust-version

@@ -1 +1 @@
-317d14a56cb8c748bf0e2f2afff89c2249ab4423
+604f185fae9a4b0edf7e28f616a0f53880f8f074

src/tools/miri/src/borrow_tracker/mod.rs

@@ -65,7 +65,7 @@ pub struct FrameState {
     /// incremental updates of the global list of protected tags stored in the
     /// `stacked_borrows::GlobalState` upon function return, and if we attempt to pop a protected
     /// tag, to identify which call is responsible for protecting the tag.
-    /// See `Stack::item_popped` for more explanation.
+    /// See `Stack::item_invalidated` for more explanation.
     /// Tree Borrows also needs to know which allocation these tags
     /// belong to so that it can perform a read through them immediately before
     /// the frame gets popped.
@@ -76,8 +76,10 @@ pub struct FrameState {
 }
 
 impl VisitProvenance for FrameState {
-    fn visit_provenance(&self, _visit: &mut VisitWith<'_>) {
-        // `protected_tags` are already recorded by `GlobalStateInner`.
+    fn visit_provenance(&self, visit: &mut VisitWith<'_>) {
+        for (id, tag) in &self.protected_tags {
+            visit(Some(*id), Some(*tag));
+        }
     }
 }
 
@@ -98,7 +100,7 @@ pub struct GlobalStateInner {
     /// An item is protected if its tag is in this set, *and* it has the "protected" bit set.
     /// We add tags to this when they are created with a protector in `reborrow`, and
     /// we remove tags from this when the call which is protecting them returns, in
-    /// `GlobalStateInner::end_call`. See `Stack::item_popped` for more details.
+    /// `GlobalStateInner::end_call`. See `Stack::item_invalidated` for more details.
     protected_tags: FxHashMap<BorTag, ProtectorKind>,
     /// The pointer ids to trace
     tracked_pointer_tags: FxHashSet<BorTag>,
@@ -111,10 +113,8 @@ pub struct GlobalStateInner {
 }
 
 impl VisitProvenance for GlobalStateInner {
-    fn visit_provenance(&self, visit: &mut VisitWith<'_>) {
-        for &tag in self.protected_tags.keys() {
-            visit(None, Some(tag));
-        }
+    fn visit_provenance(&self, _visit: &mut VisitWith<'_>) {
+        // All the provenance in protected_tags is also stored in FrameState, and visited there.
         // The only other candidate is base_ptr_tags, and that does not need visiting since we don't ever
         // GC the bottommost/root tag.
     }

src/tools/miri/src/borrow_tracker/stacked_borrows/diagnostics.rs

@@ -5,9 +5,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_span::{Span, SpanData};
 use rustc_target::abi::Size;
 
-use crate::borrow_tracker::{
-    AccessKind, GlobalStateInner, ProtectorKind,
-};
+use crate::borrow_tracker::{AccessKind, GlobalStateInner, ProtectorKind};
 use crate::*;
 
 /// Error reporting

src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs

@@ -18,7 +18,8 @@ use rustc_target::abi::{Abi, Size};
 
 use crate::borrow_tracker::{
     stacked_borrows::diagnostics::{AllocHistory, DiagnosticCx, DiagnosticCxBuilder},
-    AccessKind, GlobalStateInner, ProtectorKind,};
+    AccessKind, GlobalStateInner, ProtectorKind,
+};
 use crate::*;
 
 use diagnostics::{RetagCause, RetagInfo};

src/tools/miri/src/borrow_tracker/tree_borrows/mod.rs

@@ -2,9 +2,7 @@ use log::trace;
 
 use rustc_target::abi::{Abi, Size};
 
-use crate::borrow_tracker::{
-    AccessKind, GlobalState, GlobalStateInner, ProtectorKind,
-};
+use crate::borrow_tracker::{AccessKind, GlobalState, GlobalStateInner, ProtectorKind};
 use rustc_middle::{
     mir::{Mutability, RetagKind},
     ty::{

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

@@ -38,7 +38,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         if flags & this.eval_libc_i32("MREMAP_MAYMOVE") == 0 {
             // We only support MREMAP_MAYMOVE, so not passing the flag is just a failure
             this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
-            return Ok(Scalar::from_maybe_pointer(Pointer::null(), this));
+            return Ok(this.eval_libc("MAP_FAILED"));
         }
 
         let old_address = Machine::ptr_from_addr_cast(this, old_address)?;

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

@@ -48,11 +48,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // First, we do some basic argument validation as required by mmap
         if (flags & (map_private | map_shared)).count_ones() != 1 {
             this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
-            return Ok(Scalar::from_maybe_pointer(Pointer::null(), this));
+            return Ok(this.eval_libc("MAP_FAILED"));
         }
         if length == 0 {
             this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
-            return Ok(Scalar::from_maybe_pointer(Pointer::null(), this));
+            return Ok(this.eval_libc("MAP_FAILED"));
         }
 
         // If a user tries to map a file, we want to loudly inform them that this is not going
@@ -72,7 +72,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // Miri doesn't support MAP_FIXED or any any protections other than PROT_READ|PROT_WRITE.
         if flags & map_fixed != 0 || prot != prot_read | prot_write {
             this.set_last_error(Scalar::from_i32(this.eval_libc_i32("ENOTSUP")))?;
-            return Ok(Scalar::from_maybe_pointer(Pointer::null(), this));
+            return Ok(this.eval_libc("MAP_FAILED"));
         }
 
         // Miri does not support shared mappings, or any of the other extensions that for example