Merge pull request #4687 from rust-lang/rustup-2025-11-14

Automatic Rustup

Author: RalfJung

Cargo.lock

@@ -600,7 +600,6 @@ dependencies = [
  "serde_json",
  "tempfile",
  "termize",
- "tikv-jemalloc-sys",
  "toml 0.9.7",
  "ui_test",
  "walkdir",
@@ -1289,7 +1288,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -2155,7 +2154,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "07033963ba89ebaf1584d767badaa2e8fcec21aedea6b8c0346d487d49c28667"
 dependencies = [
  "cfg-if",
- "windows-targets 0.52.6",
+ "windows-targets 0.53.3",
 ]
 
 [[package]]
@@ -4807,7 +4806,6 @@ dependencies = [
  "stringdex",
  "tempfile",
  "threadpool",
- "tikv-jemalloc-sys",
  "tracing",
  "tracing-subscriber",
  "tracing-tree",
@@ -4907,7 +4905,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -5275,9 +5273,9 @@ dependencies = [
 
 [[package]]
 name = "stringdex"
-version = "0.0.2"
+version = "0.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18b3bd4f10d15ef859c40291769f0d85209de6b0f1c30713ff9cdf45ac43ea36"
+checksum = "556a6126952cb2f5150057c98a77cc6c771027dea2825bf7fa03d3d638b0a4f8"
 dependencies = [
  "stacker",
 ]
@@ -5539,9 +5537,9 @@ version = "0.1.0"
 
 [[package]]
 name = "tikv-jemalloc-sys"
-version = "0.6.1+5.3.0-1-ge13ca993e8ccb9ba9847cc330696e02839f328f7"
+version = "0.6.0+5.3.0-1-ge13ca993e8ccb9ba9847cc330696e02839f328f7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd8aa5b2ab86a2cefa406d889139c162cbb230092f7d1d7cbc1716405d852a3b"
+checksum = "cd3c60906412afa9c2b5b5a48ca6a5abe5736aec9eb48ad05037a677e52e4e2d"
 dependencies = [
  "cc",
  "libc",

compiler/rustc/Cargo.toml

@@ -21,9 +21,9 @@ rustc_public_bridge = { path = "../rustc_public_bridge" }
 # tidy-alphabetical-end
 
 [dependencies.tikv-jemalloc-sys]
-version = "0.6.1"
+version = "0.6.0"
 optional = true
-features = ['override_allocator_on_supported_platforms']
+features = ['unprefixed_malloc_on_supported_platforms']
 
 [features]
 # tidy-alphabetical-start

compiler/rustc/src/main.rs

@@ -7,25 +7,26 @@
 // distribution. The obvious way to do this is with the `#[global_allocator]`
 // mechanism. However, for complicated reasons (see
 // https://github.com/rust-lang/rust/pull/81782#issuecomment-784438001 for some
-// details) that mechanism doesn't work here. Also, we'd like to use a
-// consistent allocator across the rustc <-> llvm boundary, and
-// `#[global_allocator]` wouldn't provide that.
+// details) that mechanism doesn't work here. Also, we must use a consistent
+// allocator across the rustc <-> llvm boundary, and `#[global_allocator]`
+// wouldn't provide that.
 //
-// Instead, we use a lower-level mechanism, namely the
-// `"override_allocator_on_supported_platforms"` Cargo feature of jemalloc-sys.
-//
-// This makes jemalloc-sys override the libc/system allocator's implementation
-// of `malloc`, `free`, etc.. This means that Rust's `System` allocator, which
-// calls `libc::malloc()` et al., is actually calling into jemalloc.
+// Instead, we use a lower-level mechanism. rustc is linked with jemalloc in a
+// way such that jemalloc's implementation of `malloc`, `free`, etc., override
+// the libc allocator's implementation. This means that Rust's `System`
+// allocator, which calls `libc::malloc()` et al., is actually calling into
+// jemalloc.
 //
 // A consequence of not using `GlobalAlloc` (and the `tikv-jemallocator` crate
 // provides an impl of that trait, which is called `Jemalloc`) is that we
 // cannot use the sized deallocation APIs (`sdallocx`) that jemalloc provides.
 // It's unclear how much performance is lost because of this.
 //
-// NOTE: Even though Cargo passes `--extern` with `tikv_jemalloc_sys`, we still need to `use` the
-// crate for the compiler to see the `#[used]`, see https://github.com/rust-lang/rust/issues/64402.
-// This is similarly required if we used a crate with `#[global_allocator]`.
+// As for the symbol overrides in `main` below: we're pulling in a static copy
+// of jemalloc. We need to actually reference its symbols for it to get linked.
+// The two crates we link to here, `std` and `rustc_driver`, are both dynamic
+// libraries. So we must reference jemalloc symbols one way or another, because
+// this file is the only object code in the rustc executable.
 //
 // NOTE: if you are reading this comment because you want to set a custom `global_allocator` for
 // benchmarking, consider using the benchmarks in the `rustc-perf` collector suite instead:
@@ -35,9 +36,43 @@
 // to compare their performance, see
 // https://github.com/rust-lang/rust/commit/b90cfc887c31c3e7a9e6d462e2464db1fe506175#diff-43914724af6e464c1da2171e4a9b6c7e607d5bc1203fa95c0ab85be4122605ef
 // for an example of how to do so.
-#[cfg(feature = "jemalloc")]
-use tikv_jemalloc_sys as _;
 
 fn main() {
+    // See the comment at the top of this file for an explanation of this.
+    #[cfg(feature = "jemalloc")]
+    {
+        use std::os::raw::{c_int, c_void};
+
+        use tikv_jemalloc_sys as jemalloc_sys;
+
+        #[used]
+        static _F1: unsafe extern "C" fn(usize, usize) -> *mut c_void = jemalloc_sys::calloc;
+        #[used]
+        static _F2: unsafe extern "C" fn(*mut *mut c_void, usize, usize) -> c_int =
+            jemalloc_sys::posix_memalign;
+        #[used]
+        static _F3: unsafe extern "C" fn(usize, usize) -> *mut c_void = jemalloc_sys::aligned_alloc;
+        #[used]
+        static _F4: unsafe extern "C" fn(usize) -> *mut c_void = jemalloc_sys::malloc;
+        #[used]
+        static _F5: unsafe extern "C" fn(*mut c_void, usize) -> *mut c_void = jemalloc_sys::realloc;
+        #[used]
+        static _F6: unsafe extern "C" fn(*mut c_void) = jemalloc_sys::free;
+
+        // On OSX, jemalloc doesn't directly override malloc/free, but instead
+        // registers itself with the allocator's zone APIs in a ctor. However,
+        // the linker doesn't seem to consider ctors as "used" when statically
+        // linking, so we need to explicitly depend on the function.
+        #[cfg(target_os = "macos")]
+        {
+            unsafe extern "C" {
+                fn _rjem_je_zone_register();
+            }
+
+            #[used]
+            static _F7: unsafe extern "C" fn() = _rjem_je_zone_register;
+        }
+    }
+
     rustc_driver::main()
 }

compiler/rustc_ast_lowering/src/expr.rs

@@ -13,7 +13,7 @@ use rustc_middle::span_bug;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::errors::report_lit_error;
 use rustc_span::source_map::{Spanned, respan};
-use rustc_span::{DUMMY_SP, DesugaringKind, Ident, Span, Symbol, sym};
+use rustc_span::{ByteSymbol, DUMMY_SP, DesugaringKind, Ident, Span, Symbol, sym};
 use thin_vec::{ThinVec, thin_vec};
 use visit::{Visitor, walk_expr};
 
@@ -924,7 +924,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     arena_vec![self; new_unchecked, get_context],
                 ),
             };
-            self.arena.alloc(self.expr_unsafe(call))
+            self.arena.alloc(self.expr_unsafe(span, call))
         };
 
         // `::std::task::Poll::Ready(result) => break result`
@@ -1832,7 +1832,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         arena_vec![self; iter],
                     ));
                     // `unsafe { ... }`
-                    let iter = self.arena.alloc(self.expr_unsafe(iter));
+                    let iter = self.arena.alloc(self.expr_unsafe(head_span, iter));
                     let kind = self.make_lowered_await(head_span, iter, FutureKind::AsyncIterator);
                     self.arena.alloc(hir::Expr { hir_id: self.next_id(), kind, span: head_span })
                 }
@@ -1887,7 +1887,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     arena_vec![self; iter],
                 ));
                 // `unsafe { ... }`
-                let iter = self.arena.alloc(self.expr_unsafe(iter));
+                let iter = self.arena.alloc(self.expr_unsafe(head_span, iter));
                 let inner_match_expr = self.arena.alloc(self.expr_match(
                     for_span,
                     iter,
@@ -2103,30 +2103,18 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.arena.alloc(self.expr(sp, hir::ExprKind::Tup(&[])))
     }
 
-    fn expr_uint(&mut self, sp: Span, ty: ast::UintTy, value: u128) -> hir::Expr<'hir> {
+    pub(super) fn expr_str(&mut self, sp: Span, value: Symbol) -> hir::Expr<'hir> {
         let lit = hir::Lit {
             span: self.lower_span(sp),
-            node: ast::LitKind::Int(value.into(), ast::LitIntType::Unsigned(ty)),
+            node: ast::LitKind::Str(value, ast::StrStyle::Cooked),
         };
         self.expr(sp, hir::ExprKind::Lit(lit))
     }
 
-    pub(super) fn expr_usize(&mut self, sp: Span, value: usize) -> hir::Expr<'hir> {
-        self.expr_uint(sp, ast::UintTy::Usize, value as u128)
-    }
-
-    pub(super) fn expr_u32(&mut self, sp: Span, value: u32) -> hir::Expr<'hir> {
-        self.expr_uint(sp, ast::UintTy::U32, value as u128)
-    }
-
-    pub(super) fn expr_u16(&mut self, sp: Span, value: u16) -> hir::Expr<'hir> {
-        self.expr_uint(sp, ast::UintTy::U16, value as u128)
-    }
-
-    pub(super) fn expr_str(&mut self, sp: Span, value: Symbol) -> hir::Expr<'hir> {
+    pub(super) fn expr_byte_str(&mut self, sp: Span, value: ByteSymbol) -> hir::Expr<'hir> {
         let lit = hir::Lit {
             span: self.lower_span(sp),
-            node: ast::LitKind::Str(value, ast::StrStyle::Cooked),
+            node: ast::LitKind::ByteStr(value, ast::StrStyle::Cooked),
         };
         self.expr(sp, hir::ExprKind::Lit(lit))
     }
@@ -2262,9 +2250,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.expr(span, expr_path)
     }
 
-    fn expr_unsafe(&mut self, expr: &'hir hir::Expr<'hir>) -> hir::Expr<'hir> {
+    pub(super) fn expr_unsafe(
+        &mut self,
+        span: Span,
+        expr: &'hir hir::Expr<'hir>,
+    ) -> hir::Expr<'hir> {
         let hir_id = self.next_id();
-        let span = expr.span;
         self.expr(
             span,
             hir::ExprKind::Block(
@@ -2302,15 +2293,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.arena.alloc(self.expr_block(b))
     }
 
-    pub(super) fn expr_array_ref(
-        &mut self,
-        span: Span,
-        elements: &'hir [hir::Expr<'hir>],
-    ) -> hir::Expr<'hir> {
-        let array = self.arena.alloc(self.expr(span, hir::ExprKind::Array(elements)));
-        self.expr_ref(span, array)
-    }
-
     pub(super) fn expr_ref(&mut self, span: Span, expr: &'hir hir::Expr<'hir>) -> hir::Expr<'hir> {
         self.expr(span, hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, expr))
     }