test for better error location on stack pop

Author: RalfJung

tests/fail/data_race/stack_pop_race.rs

@@ -0,0 +1,22 @@
+// compile-flags: -Zmiri-preemption-rate=0
+use std::thread;
+
+#[derive(Copy, Clone)]
+struct MakeSend(*const i32);
+unsafe impl Send for MakeSend {}
+
+fn main() { race(0); }
+
+// Using an argument for the ptr to point to, since those do not get StorageDead.
+fn race(local: i32) {
+    let ptr = MakeSend(&local as *const i32);
+    thread::spawn(move || {
+        let ptr = ptr;
+        let _val = unsafe { *ptr.0 };
+    });
+    // Make the other thread go first so that it does not UAF.
+    thread::yield_now();
+    // Deallocating the local (when `main` returns)
+    // races with the read in the other thread.
+    // Make sure the error points at this function's end, not just the call site.
+} //~ERROR Data race detected between Deallocate on thread `main` and Read on thread `<unnamed>`

tests/fail/data_race/stack_pop_race.stderr

@@ -0,0 +1,20 @@
+error: Undefined Behavior: Data race detected between Deallocate on thread `main` and Read on thread `<unnamed>` at ALLOC
+  --> $DIR/stack_pop_race.rs:LL:CC
+   |
+LL | }
+   |  ^ Data race detected between Deallocate on thread `main` and Read on thread `<unnamed>` at ALLOC
+   |
+   = 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 `race` at $DIR/stack_pop_race.rs:LL:CC
+note: inside `main` at $DIR/stack_pop_race.rs:LL:CC
+  --> $DIR/stack_pop_race.rs:LL:CC
+   |
+LL | fn main() { race(0); }
+   |             ^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to previous error
+