add test for intermediate reference in '&(*x).0 as *const i32'

src/tools/miri/tests/fail/dangling_pointers/dangling_pointer_to_raw_pointer.rs

@@ -0,0 +1,20 @@
+#![feature(raw_ref_op)]
+#![feature(strict_provenance)]
+use std::ptr;
+
+fn direct_raw(x: *const (i32, i32)) -> *const i32 {
+ unsafe { &raw const (*x).0 }
+}
+
+// Ensure that if a raw pointer is created via an intermediate
+// reference, we catch that. (Just in case someone decides to
+// desugar this differenly or so.)
+fn via_ref(x: *const (i32, i32)) -> *const i32 {
+ unsafe { &(*x).0 as *const i32 } //~ERROR: dangling pointer
+}
+
+fn main() {
+ let ptr = ptr::without_provenance(0x10);
+ direct_raw(ptr); // this is fine
+ via_ref(ptr); // this is not
+}

src/tools/miri/tests/fail/dangling_pointers/dangling_pointer_to_raw_pointer.stderr

@@ -0,0 +1,20 @@
+error: Undefined Behavior: out-of-bounds pointer use: 0x10[noalloc] is a dangling pointer (it has no provenance)
+ --> $DIR/dangling_pointer_to_raw_pointer.rs:LL:CC
+ |
+LL | unsafe { &(*x).0 as *const i32 }
+ | ^^^^^^^ out-of-bounds pointer use: 0x10[noalloc] is a dangling pointer (it has no provenance)
+ |
+ = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+ = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+ = note: BACKTRACE:
+ = note: inside `via_ref` at $DIR/dangling_pointer_to_raw_pointer.rs:LL:CC
+note: inside `main`
+ --> $DIR/dangling_pointer_to_raw_pointer.rs:LL:CC
+ |
+LL | via_ref(ptr); // this is not
+ | ^^^^^^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+