Rollup of 9 pull requests

README.md

@@ -21,7 +21,7 @@ standard library, and documentation.
 
 ## Why Rust?
 
-- **Performance:** Fast and memory-efficient, suitable for critical services, embedded devices, and easily integrate with other languages.
+- **Performance:** Fast and memory-efficient, suitable for critical services, embedded devices, and easily integrated with other languages.
 
 - **Reliability:** Our rich type system and ownership model ensure memory and thread safety, reducing bugs at compile-time.
 

compiler/rustc_const_eval/src/interpret/place.rs

@@ -5,8 +5,7 @@
 use std::assert_matches::assert_matches;
 
 use either::{Either, Left, Right};
-use rustc_abi::{Align, BackendRepr, HasDataLayout, Size};
-use rustc_ast::Mutability;
+use rustc_abi::{BackendRepr, HasDataLayout, Size};
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::{bug, mir, span_bug};
@@ -1018,40 +1017,31 @@ where
         self.allocate_dyn(layout, kind, MemPlaceMeta::None)
     }
 
-    /// Allocates a sequence of bytes in the interpreter's memory.
-    /// For immutable allocations, uses deduplication to reuse existing memory.
-    /// For mutable allocations, creates a new unique allocation.
-    pub fn allocate_bytes(
+    /// Allocates a sequence of bytes in the interpreter's memory with alignment 1.
+    /// This is allocated in immutable global memory and deduplicated.
+    pub fn allocate_bytes_dedup(
         &mut self,
         bytes: &[u8],
-        align: Align,
-        kind: MemoryKind<M::MemoryKind>,
-        mutbl: Mutability,
     ) -> InterpResult<'tcx, Pointer<M::Provenance>> {
-        // Use cache for immutable strings.
-        if mutbl.is_not() {
-            // Use dedup'd allocation function.
-            let salt = M::get_global_alloc_salt(self, None);
-            let id = self.tcx.allocate_bytes_dedup(bytes, salt);
-
-            // Turn untagged "global" pointers (obtained via `tcx`) into the machine pointer to the allocation.
-            M::adjust_alloc_root_pointer(&self, Pointer::from(id), Some(kind))
-        } else {
-            // Allocate new memory for mutable data.
-            self.allocate_bytes_ptr(bytes, align, kind, mutbl)
-        }
+        let salt = M::get_global_alloc_salt(self, None);
+        let id = self.tcx.allocate_bytes_dedup(bytes, salt);
+
+        // Turn untagged "global" pointers (obtained via `tcx`) into the machine pointer to the allocation.
+        M::adjust_alloc_root_pointer(
+            &self,
+            Pointer::from(id),
+            M::GLOBAL_KIND.map(MemoryKind::Machine),
+        )
     }
 
-    /// Allocates a string in the interpreter's memory with metadata for length.
-    /// Uses `allocate_bytes` internally but adds string-specific metadata handling.
-    pub fn allocate_str(
+    /// Allocates a string in the interpreter's memory, returning it as a (wide) place.
+    /// This is allocated in immutable global memory and deduplicated.
+    pub fn allocate_str_dedup(
         &mut self,
         str: &str,
-        kind: MemoryKind<M::MemoryKind>,
-        mutbl: Mutability,
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::Provenance>> {
         let bytes = str.as_bytes();
-        let ptr = self.allocate_bytes(bytes, Align::ONE, kind, mutbl)?;
+        let ptr = self.allocate_bytes_dedup(bytes)?;
 
         // Create length metadata for the string.
         let meta = Scalar::from_target_usize(u64::try_from(bytes.len()).unwrap(), self);

compiler/rustc_const_eval/src/util/caller_location.rs

@@ -1,7 +1,7 @@
 use rustc_hir::LangItem;
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::LayoutOf;
-use rustc_middle::ty::{self, Mutability};
+use rustc_middle::ty::{self};
 use rustc_middle::{bug, mir};
 use rustc_span::symbol::Symbol;
 use tracing::trace;
@@ -20,12 +20,9 @@ fn alloc_caller_location<'tcx>(
     // This can fail if rustc runs out of memory right here. Trying to emit an error would be
     // pointless, since that would require allocating more memory than these short strings.
     let file = if loc_details.file {
-        ecx.allocate_str(filename.as_str(), MemoryKind::CallerLocation, Mutability::Not).unwrap()
+        ecx.allocate_str_dedup(filename.as_str()).unwrap()
     } else {
-        // FIXME: This creates a new allocation each time. It might be preferable to
-        // perform this allocation only once, and re-use the `MPlaceTy`.
-        // See https://github.com/rust-lang/rust/pull/89920#discussion_r730012398
-        ecx.allocate_str("<redacted>", MemoryKind::CallerLocation, Mutability::Not).unwrap()
+        ecx.allocate_str_dedup("<redacted>").unwrap()
     };
     let file = file.map_provenance(CtfeProvenance::as_immutable);
     let line = if loc_details.line { Scalar::from_u32(line) } else { Scalar::from_u32(0) };

compiler/rustc_lexer/src/lib.rs

@@ -33,6 +33,7 @@ pub mod unescape;
 mod tests;
 
 use unicode_properties::UnicodeEmoji;
+pub use unicode_xid::UNICODE_VERSION as UNICODE_XID_VERSION;
 
 use self::LiteralKind::*;
 use self::TokenKind::*;

compiler/rustc_middle/src/ty/context.rs

@@ -1479,7 +1479,7 @@ impl<'tcx> TyCtxt<'tcx> {
         self.mk_adt_def_from_data(ty::AdtDefData::new(self, did, kind, variants, repr))
     }
 
-    /// Allocates a read-only byte or string literal for `mir::interpret`.
+    /// Allocates a read-only byte or string literal for `mir::interpret` with alignment 1.
     /// Returns the same `AllocId` if called again with the same bytes.
     pub fn allocate_bytes_dedup(self, bytes: &[u8], salt: usize) -> interpret::AllocId {
         // Create an allocation that just contains these bytes.

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -534,8 +534,13 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
             // This allows the set of visited edges to grow monotonically with the lattice.
             FlatSet::Bottom => TerminatorEdges::None,
             FlatSet::Elem(scalar) => {
-                let choice = scalar.assert_scalar_int().to_bits_unchecked();
-                TerminatorEdges::Single(targets.target_for_value(choice))
+                if let Ok(scalar_int) = scalar.try_to_scalar_int() {
+                    TerminatorEdges::Single(
+                        targets.target_for_value(scalar_int.to_bits_unchecked()),
+                    )
+                } else {
+                    TerminatorEdges::SwitchInt { discr, targets }
+                }
             }
             FlatSet::Top => TerminatorEdges::SwitchInt { discr, targets },
         }

compiler/rustc_parse/src/lexer/mod.rs

@@ -822,7 +822,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
 
     /// Detect guarded string literal syntax
     ///
-    /// RFC 3598 reserved this syntax for future use. As of Rust 2024,
+    /// RFC 3593 reserved this syntax for future use. As of Rust 2024,
     /// using this syntax produces an error. In earlier editions, however, it
     /// only results in an (allowed by default) lint, and is treated as
     /// separate tokens.

compiler/rustc_parse/src/lib.rs

@@ -24,6 +24,7 @@ use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Diag, FatalError, PResult};
 use rustc_session::parse::ParseSess;
 use rustc_span::{FileName, SourceFile, Span};
+pub use unicode_normalization::UNICODE_VERSION as UNICODE_NORMALIZATION_VERSION;
 
 pub const MACRO_ARGUMENTS: Option<&str> = Some("macro arguments");
 

library/core/src/ops/control_flow.rs

@@ -141,8 +141,8 @@ impl<B, C> ControlFlow<B, C> {
     /// ```
     /// use std::ops::ControlFlow;
     ///
-    /// assert!(ControlFlow::<i32, String>::Break(3).is_break());
-    /// assert!(!ControlFlow::<String, i32>::Continue(3).is_break());
+    /// assert!(ControlFlow::<&str, i32>::Break("Stop right there!").is_break());
+    /// assert!(!ControlFlow::<&str, i32>::Continue(3).is_break());
     /// ```
     #[inline]
     #[stable(feature = "control_flow_enum_is", since = "1.59.0")]
@@ -157,8 +157,8 @@ impl<B, C> ControlFlow<B, C> {
     /// ```
     /// use std::ops::ControlFlow;
     ///
-    /// assert!(!ControlFlow::<i32, String>::Break(3).is_continue());
-    /// assert!(ControlFlow::<String, i32>::Continue(3).is_continue());
+    /// assert!(!ControlFlow::<&str, i32>::Break("Stop right there!").is_continue());
+    /// assert!(ControlFlow::<&str, i32>::Continue(3).is_continue());
     /// ```
     #[inline]
     #[stable(feature = "control_flow_enum_is", since = "1.59.0")]
@@ -174,8 +174,8 @@ impl<B, C> ControlFlow<B, C> {
     /// ```
     /// use std::ops::ControlFlow;
     ///
-    /// assert_eq!(ControlFlow::<i32, String>::Break(3).break_value(), Some(3));
-    /// assert_eq!(ControlFlow::<String, i32>::Continue(3).break_value(), None);
+    /// assert_eq!(ControlFlow::<&str, i32>::Break("Stop right there!").break_value(), Some("Stop right there!"));
+    /// assert_eq!(ControlFlow::<&str, i32>::Continue(3).break_value(), None);
     /// ```
     #[inline]
     #[stable(feature = "control_flow_enum", since = "1.83.0")]
@@ -205,8 +205,8 @@ impl<B, C> ControlFlow<B, C> {
     /// ```
     /// use std::ops::ControlFlow;
     ///
-    /// assert_eq!(ControlFlow::<i32, String>::Break(3).continue_value(), None);
-    /// assert_eq!(ControlFlow::<String, i32>::Continue(3).continue_value(), Some(3));
+    /// assert_eq!(ControlFlow::<&str, i32>::Break("Stop right there!").continue_value(), None);
+    /// assert_eq!(ControlFlow::<&str, i32>::Continue(3).continue_value(), Some(3));
     /// ```
     #[inline]
     #[stable(feature = "control_flow_enum", since = "1.83.0")]

src/bootstrap/src/bin/main.rs

@@ -48,9 +48,9 @@ fn main() {
             err => {
                 drop(err);
                 if let Ok(pid) = pid {
-                    println!("WARNING: build directory locked by process {pid}, waiting for lock");
+                    eprintln!("WARNING: build directory locked by process {pid}, waiting for lock");
                 } else {
-                    println!("WARNING: build directory locked, waiting for lock");
+                    eprintln!("WARNING: build directory locked, waiting for lock");
                 }
                 let mut lock = t!(build_lock.write());
                 t!(lock.write(process::id().to_string().as_ref()));
@@ -70,13 +70,13 @@ fn main() {
     // changelog warning, not the `x.py setup` message.
     let suggest_setup = config.config.is_none() && !matches!(config.cmd, Subcommand::Setup { .. });
     if suggest_setup {
-        println!("WARNING: you have not made a `config.toml`");
-        println!(
+        eprintln!("WARNING: you have not made a `config.toml`");
+        eprintln!(
             "HELP: consider running `./x.py setup` or copying `config.example.toml` by running \
             `cp config.example.toml config.toml`"
         );
     } else if let Some(suggestion) = &changelog_suggestion {
-        println!("{suggestion}");
+        eprintln!("{suggestion}");
     }
 
     let pre_commit = config.src.join(".git").join("hooks").join("pre-commit");
@@ -86,13 +86,13 @@ fn main() {
     Build::new(config).build();
 
     if suggest_setup {
-        println!("WARNING: you have not made a `config.toml`");
-        println!(
+        eprintln!("WARNING: you have not made a `config.toml`");
+        eprintln!(
             "HELP: consider running `./x.py setup` or copying `config.example.toml` by running \
             `cp config.example.toml config.toml`"
         );
     } else if let Some(suggestion) = &changelog_suggestion {
-        println!("{suggestion}");
+        eprintln!("{suggestion}");
     }
 
     // Give a warning if the pre-commit script is in pre-commit and not pre-push.
@@ -102,14 +102,14 @@ fn main() {
     if fs::read_to_string(pre_commit).is_ok_and(|contents| {
         contents.contains("https://github.com/rust-lang/rust/issues/77620#issuecomment-705144570")
     }) {
-        println!(
+        eprintln!(
             "WARNING: You have the pre-push script installed to .git/hooks/pre-commit. \
                   Consider moving it to .git/hooks/pre-push instead, which runs less often."
         );
     }
 
     if suggest_setup || changelog_suggestion.is_some() {
-        println!("NOTE: this message was printed twice to make it more likely to be seen");
+        eprintln!("NOTE: this message was printed twice to make it more likely to be seen");
     }
 
     if dump_bootstrap_shims {

src/bootstrap/src/bin/rustc.rs

@@ -306,7 +306,7 @@ fn main() {
         // should run on success, after this block.
     }
     if verbose > 0 {
-        println!("\nDid not run successfully: {status}\n{cmd:?}\n-------------");
+        eprintln!("\nDid not run successfully: {status}\n{cmd:?}\n-------------");
     }
 
     if let Some(mut on_fail) = on_fail {

src/bootstrap/src/core/build_steps/check.rs

@@ -287,7 +287,7 @@ impl Step for CodegenBackend {
     fn run(self, builder: &Builder<'_>) {
         // FIXME: remove once https://github.com/rust-lang/rust/issues/112393 is resolved
         if builder.build.config.vendor && self.backend == "gcc" {
-            println!("Skipping checking of `rustc_codegen_gcc` with vendoring enabled.");
+            eprintln!("Skipping checking of `rustc_codegen_gcc` with vendoring enabled.");
             return;
         }
 

src/bootstrap/src/core/build_steps/compile.rs

@@ -1611,7 +1611,7 @@ impl Step for Sysroot {
         let sysroot = sysroot_dir(compiler.stage);
 
         builder
-            .verbose(|| println!("Removing sysroot {} to avoid caching bugs", sysroot.display()));
+            .verbose(|| eprintln!("Removing sysroot {} to avoid caching bugs", sysroot.display()));
         let _ = fs::remove_dir_all(&sysroot);
         t!(fs::create_dir_all(&sysroot));
 
@@ -1681,7 +1681,7 @@ impl Step for Sysroot {
                     return true;
                 }
                 if !filtered_files.iter().all(|f| f != path.file_name().unwrap()) {
-                    builder.verbose_than(1, || println!("ignoring {}", path.display()));
+                    builder.verbose_than(1, || eprintln!("ignoring {}", path.display()));
                     false
                 } else {
                     true
@@ -2240,7 +2240,7 @@ pub fn stream_cargo(
         cargo.arg(arg);
     }
 
-    builder.verbose(|| println!("running: {cargo:?}"));
+    builder.verbose(|| eprintln!("running: {cargo:?}"));
 
     if builder.config.dry_run() {
         return true;
@@ -2261,12 +2261,12 @@ pub fn stream_cargo(
             Ok(msg) => {
                 if builder.config.json_output {
                     // Forward JSON to stdout.
-                    println!("{line}");
+                    eprintln!("{line}");
                 }
                 cb(msg)
             }
             // If this was informational, just print it out and continue
-            Err(_) => println!("{line}"),
+            Err(_) => eprintln!("{line}"),
         }
     }
 

src/bootstrap/src/core/build_steps/dist.rs

@@ -2080,7 +2080,7 @@ fn maybe_install_llvm(
     {
         let mut cmd = command(llvm_config);
         cmd.arg("--libfiles");
-        builder.verbose(|| println!("running {cmd:?}"));
+        builder.verbose(|| eprintln!("running {cmd:?}"));
         let files = cmd.run_capture_stdout(builder).stdout();
         let build_llvm_out = &builder.llvm_out(builder.config.build);
         let target_llvm_out = &builder.llvm_out(target);

src/bootstrap/src/core/build_steps/format.rs

@@ -107,10 +107,10 @@ fn print_paths(verb: &str, adjective: Option<&str>, paths: &[String]) {
         if let Some(adjective) = adjective { format!("{adjective} ") } else { String::new() };
     if len <= 10 {
         for path in paths {
-            println!("fmt: {verb} {adjective}file {path}");
+            eprintln!("fmt: {verb} {adjective}file {path}");
         }
     } else {
-        println!("fmt: {verb} {len} {adjective}files");
+        eprintln!("fmt: {verb} {len} {adjective}files");
     }
 }
 
@@ -199,7 +199,7 @@ pub fn format(build: &Builder<'_>, check: bool, all: bool, paths: &[PathBuf]) {
                 match get_modified_rs_files(build) {
                     Ok(Some(files)) => {
                         if files.is_empty() {
-                            println!("fmt info: No modified files detected for formatting.");
+                            eprintln!("fmt info: No modified files detected for formatting.");
                             return;
                         }