Auto merge of #3224 - rust-lang:rustup-2023-12-14, r=saethlin

Automatic Rustup

Author: bors

rust-version

@@ -1 +1 @@
-e2a3c9b3f0895c866c104bd2fff2a8bf16eaf964
+e6d1b0ec9859e6f5c29aaa3b6525fb625bf354ad

src/bin/miri.rs

@@ -144,7 +144,7 @@ impl rustc_driver::Callbacks for MiriBeRustCompilerCalls {
                             // Otherwise it may cause unexpected behaviours and ICEs
                             // (https://github.com/rust-lang/rust/issues/86261).
                             let is_reachable_non_generic = matches!(
-                                tcx.hir().get(tcx.local_def_id_to_hir_id(local_def_id)),
+                                tcx.hir_node_by_def_id(local_def_id),
                                 Node::Item(&hir::Item {
                                     kind: hir::ItemKind::Static(..) | hir::ItemKind::Fn(..),
                                     ..

tests/fail/extern-type-field-offset.rs

@@ -0,0 +1,29 @@
+#![feature(extern_types)]
+
+extern "C" {
+    type Opaque;
+}
+
+struct Newtype(Opaque);
+
+struct S {
+    i: i32,
+    j: i32,
+    a: Newtype,
+}
+
+fn main() {
+    let buf = [0i32; 4];
+
+    let x: &Newtype = unsafe { &*(&buf as *const _ as *const Newtype) };
+    // Projecting to the newtype works, because it is always at offset 0.
+    let _field = &x.0;
+
+    let x: &S = unsafe { &*(&buf as *const _ as *const S) };
+    // Accessing sized fields is perfectly fine, even at non-zero offsets.
+    let _field = &x.i;
+    let _field = &x.j;
+    // This needs to compute the field offset, but we don't know the type's alignment,
+    // so this panics.
+    let _field = &x.a; //~ERROR: does not have a known offset
+}

tests/fail/extern-type-field-offset.stderr

@@ -0,0 +1,14 @@
+error: unsupported operation: `extern type` does not have a known offset
+  --> $DIR/extern-type-field-offset.rs:LL:CC
+   |
+LL |     let _field = &x.a;
+   |                  ^^^^ `extern type` does not have a known offset
+   |
+   = help: this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support
+   = note: BACKTRACE:
+   = note: inside `main` at $DIR/extern-type-field-offset.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+