Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/tests/ui/consts/ptr_comparisons.rs b/tests/ui/consts/ptr_comparisons.rs
new file mode 100644
index 000000000..f442e6138
--- /dev/null
+++ b/tests/ui/consts/ptr_comparisons.rs
@@ -0,0 +1,63 @@
+// compile-flags: --crate-type=lib
+// normalize-stderr-32bit: "8 bytes" -> "$$TWO_WORDS bytes"
+// normalize-stderr-64bit: "16 bytes" -> "$$TWO_WORDS bytes"
+// normalize-stderr-32bit: "size 4" -> "size $$WORD"
+// normalize-stderr-64bit: "size 8" -> "size $$WORD"
+
+#![feature(
+    core_intrinsics,
+    const_raw_ptr_comparison,
+)]
+
+const FOO: &usize = &42;
+
+macro_rules! check {
+    (eq, $a:expr, $b:expr) => {
+        pub const _: () =
+            assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 1);
+    };
+    (ne, $a:expr, $b:expr) => {
+        pub const _: () =
+            assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 0);
+    };
+    (!, $a:expr, $b:expr) => {
+        pub const _: () =
+            assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 2);
+    };
+}
+
+check!(eq, 0, 0);
+check!(ne, 0, 1);
+check!(ne, FOO as *const _, 0);
+check!(ne, unsafe { (FOO as *const usize).offset(1) }, 0);
+check!(ne, unsafe { (FOO as *const usize as *const u8).offset(3) }, 0);
+
+// We want pointers to be equal to themselves, but aren't checking this yet because
+// there are some open questions (e.g. whether function pointers to the same function
+// compare equal, they don't necessarily at runtime).
+// The case tested here should work eventually, but does not work yet.
+check!(!, FOO as *const _, FOO as *const _);
+
+
+///////////////////////////////////////////////////////////////////////////////
+// If any of the below start compiling, make sure to add a `check` test for it.
+// These invocations exist as canaries so we don't forget to check that the
+// behaviour of `guaranteed_eq` and `guaranteed_ne` is still correct.
+// All of these try to obtain an out of bounds pointer in some manner. If we
+// can create out of bounds pointers, we can offset a pointer far enough that
+// at runtime it would be zero and at compile-time it would not be zero.
+
+const _: *const usize = unsafe { (FOO as *const usize).offset(2) };
+
+const _: *const u8 =
+    unsafe { std::ptr::addr_of!((*(FOO as *const usize as *const [u8; 1000]))[999]) };
+//~^ ERROR evaluation of constant value failed
+//~| out-of-bounds
+
+const _: usize = unsafe { std::mem::transmute::<*const usize, usize>(FOO) + 4 };
+//~^ ERROR evaluation of constant value failed
+//~| unable to turn pointer into raw bytes
+
+const _: usize = unsafe { *std::mem::transmute::<&&usize, &usize>(&FOO) + 4 };
+//~^ ERROR evaluation of constant value failed
+//~| unable to turn pointer into raw bytes