make sure even unleashed miri does not do pointer stuff

Author: RalfJung

src/test/ui/consts/miri_unleashed/ptr_arith.rs

@@ -0,0 +1,29 @@
+// compile-flags: -Zunleash-the-miri-inside-of-you
+#![feature(core_intrinsics)]
+#![allow(const_err)]
+
+// A test demonstrating that we prevent doing even trivial
+// pointer arithmetic or comparison during CTFE.
+
+static CMP: () = {
+    let x = &0 as *const _;
+    let _v = x == x;
+    //~^ ERROR could not evaluate static initializer
+    //~| NOTE pointer arithmetic or comparison
+};
+
+static INT_PTR_ARITH: () = unsafe {
+    let x: usize = std::mem::transmute(&0);
+    let _v = x + 0;
+    //~^ ERROR could not evaluate static initializer
+    //~| NOTE pointer-to-integer cast
+};
+
+static PTR_ARITH: () = unsafe {
+    let x = &0 as *const _;
+    let _v = core::intrinsics::offset(x, 0);
+    //~^ ERROR could not evaluate static initializer
+    //~| NOTE calling intrinsic `offset`
+};
+
+fn main() {}

src/test/ui/consts/miri_unleashed/ptr_arith.stderr

@@ -0,0 +1,39 @@
+error[E0080]: could not evaluate static initializer
+  --> $DIR/ptr_arith.rs:10:14
+   |
+LL |     let _v = x == x;
+   |              ^^^^^^ "pointer arithmetic or comparison" needs an rfc before being allowed inside constants
+
+error[E0080]: could not evaluate static initializer
+  --> $DIR/ptr_arith.rs:17:14
+   |
+LL |     let _v = x + 0;
+   |              ^^^^^ "pointer-to-integer cast" needs an rfc before being allowed inside constants
+
+error[E0080]: could not evaluate static initializer
+  --> $DIR/ptr_arith.rs:24:14
+   |
+LL |     let _v = core::intrinsics::offset(x, 0);
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ "calling intrinsic `offset`" needs an rfc before being allowed inside constants
+
+warning: skipping const checks
+   |
+help: skipping check for `const_compare_raw_pointers` feature
+  --> $DIR/ptr_arith.rs:10:14
+   |
+LL |     let _v = x == x;
+   |              ^^^^^^
+help: skipping check that does not even have a feature gate
+  --> $DIR/ptr_arith.rs:16:20
+   |
+LL |     let x: usize = std::mem::transmute(&0);
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^
+help: skipping check that does not even have a feature gate
+  --> $DIR/ptr_arith.rs:24:14
+   |
+LL |     let _v = core::intrinsics::offset(x, 0);
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0080`.