const-eval: disable pointer fragment support

5 files changed, 54 insertions, 0 deletions

diff --git a/tests/ui/consts/const-eval/ptr_fragments.rs b/tests/ui/consts/const-eval/ptr_fragments.rs
index 04dcbe55590..7dc5870f89e 100644
--- a/tests/ui/consts/const-eval/ptr_fragments.rs
+++ b/tests/ui/consts/const-eval/ptr_fragments.rs
@@ -1,5 +1,6 @@
 //! Test that various operations involving pointer fragments work as expected.
 //@ run-pass
+//@ ignore-test: disabled due to <https://github.com/rust-lang/rust/issues/146291>
 
 use std::mem::{self, MaybeUninit, transmute};
 use std::ptr;
diff --git a/tests/ui/consts/const-eval/ptr_fragments_in_final.rs b/tests/ui/consts/const-eval/ptr_fragments_in_final.rs
index e2f3f51b086..aed33d7ed8d 100644
--- a/tests/ui/consts/const-eval/ptr_fragments_in_final.rs
+++ b/tests/ui/consts/const-eval/ptr_fragments_in_final.rs
@@ -1,4 +1,5 @@
 //! Test that we properly error when there is a pointer fragment in the final value.
+//@ ignore-test: disabled due to <https://github.com/rust-lang/rust/issues/146291>
 
 use std::{mem::{self, MaybeUninit}, ptr};
 
diff --git a/tests/ui/consts/const-eval/ptr_fragments_mixed.rs b/tests/ui/consts/const-eval/ptr_fragments_mixed.rs
new file mode 100644
index 00000000000..79a42820f50
--- /dev/null
+++ b/tests/ui/consts/const-eval/ptr_fragments_mixed.rs
@@ -0,0 +1,28 @@
+//! This mixes fragments from different pointers to the same allocarion, in a way
+//! that we should not accept. See <https://github.com/rust-lang/rust/issues/146291>.
+static A: u8 = 123;
+
+const HALF_PTR: usize = std::mem::size_of::<*const ()>() / 2;
+
+const fn mix_ptr() -> *const u8 {
+    unsafe {
+        let x: *const u8 = &raw const A;
+        let mut y = x.wrapping_add(usize::MAX / 4);
+        core::ptr::copy_nonoverlapping(
+            (&raw const x).cast::<u8>(),
+            (&raw mut y).cast::<u8>(),
+            HALF_PTR,
+        );
+        y
+    }
+}
+
+const APTR: *const u8 = mix_ptr(); //~ERROR: unable to read parts of a pointer
+
+fn main() {
+    let a = APTR;
+    println!("{a:p}");
+    let b = mix_ptr();
+    println!("{b:p}");
+    assert_eq!(a, b);
+}
diff --git a/tests/ui/consts/const-eval/ptr_fragments_mixed.stderr b/tests/ui/consts/const-eval/ptr_fragments_mixed.stderr
new file mode 100644
index 00000000000..9e991ab7a7d
--- /dev/null
+++ b/tests/ui/consts/const-eval/ptr_fragments_mixed.stderr
@@ -0,0 +1,23 @@
+error[E0080]: unable to read parts of a pointer from memory at ALLOC0
+  --> $DIR/ptr_fragments_mixed.rs:20:25
+   |
+LL | const APTR: *const u8 = mix_ptr();
+   |                         ^^^^^^^^^ evaluation of `APTR` failed inside this call
+   |
+   = help: this code performed an operation that depends on the underlying bytes representing a pointer
+   = help: the absolute address of a pointer is not known at compile-time, so such operations are not supported
+note: inside `mix_ptr`
+  --> $DIR/ptr_fragments_mixed.rs:11:9
+   |
+LL | /         core::ptr::copy_nonoverlapping(
+LL | |             (&raw const x).cast::<u8>(),
+LL | |             (&raw mut y).cast::<u8>(),
+LL | |             HALF_PTR,
+LL | |         );
+   | |_________^
+note: inside `std::ptr::copy_nonoverlapping::<u8>`
+  --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/read_partial_ptr.rs b/tests/ui/consts/const-eval/read_partial_ptr.rs
index bccef9c0bc6..c153e274e41 100644
--- a/tests/ui/consts/const-eval/read_partial_ptr.rs
+++ b/tests/ui/consts/const-eval/read_partial_ptr.rs
@@ -1,4 +1,5 @@
 //! Ensure we error when trying to load from a pointer whose provenance has been messed with.
+//@ ignore-test: disabled due to <https://github.com/rust-lang/rust/issues/146291>
 
 const PARTIAL_OVERWRITE: () = {
     let mut p = &42;