Add test case for #1894

src/test/run-pass/last-use-corner-cases.rs

@@ -0,0 +1,31 @@
+fn main() {
+    // Make sure closing over can be a last use
+    let q = ~10;
+    let addr = ptr::addr_of(*q);
+    let f = fn@() -> *int { ptr::addr_of(*q) };
+    assert addr == f();
+
+    // But only when it really is the last use
+    let q = ~20;
+    let f = fn@() -> *int { ptr::addr_of(*q) };
+    assert ptr::addr_of(*q) != f();
+
+    // Ensure function arguments and box arguments interact sanely.
+    fn call_me(x: fn() -> int, y: ~int) { assert x() == *y; }
+    let q = ~30;
+    call_me({|| *q}, q);
+
+    // Check that no false positives are found in loops.
+    let q = ~40, p = 10;
+    while true {
+        let i = q;
+        p += *i;
+        if p > 100 { break; }
+    }
+
+    // Verify that blocks can't interfere with each other.
+    fn two_blocks(a: fn(), b: fn()) { a(); b(); a(); b(); }
+    let q = ~50;
+    two_blocks({|| let a = q; assert *a == 50;},
+               {|| let a = q; assert *a == 50;});
+}