Tests for 2229 lint

Author: arora-aman

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop.rs

@@ -0,0 +1,130 @@
+#![deny(disjoint_capture_drop_reorder)]
+//~^ NOTE: the lint level is defined here
+
+// Test cases for types that implement a insignificant drop (stlib defined)
+
+// `t` needs Drop because one of its elements needs drop,
+// therefore precise capture might affect drop ordering
+fn test1_all_need_migration() {
+    let t = (String::new(), String::new());
+    let t1 = (String::new(), String::new());
+    let t2 = (String::new(), String::new());
+
+    let c = || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t, t1, t2) = (t, t1, t2);
+        let _t = t.0;
+        let _t1 = t1.0;
+        let _t2 = t2.0;
+    };
+
+    c();
+}
+
+// String implements drop and therefore should be migrated.
+// But in this test cases, `t2` is completely captured and when it is dropped won't be affected
+fn test2_only_precise_paths_need_migration() {
+    let t = (String::new(), String::new());
+    let t1 = (String::new(), String::new());
+    let t2 = (String::new(), String::new());
+
+    let c = || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t, t1) = (t, t1);
+        let _t = t.0;
+        let _t1 = t1.0;
+        let _t2 = t2;
+    };
+
+    c();
+}
+
+// If a variable would've not been captured by value then it would've not been
+// dropped with the closure and therefore doesn't need migration.
+fn test3_only_by_value_need_migration() {
+    let t = (String::new(), String::new());
+    let t1 = (String::new(), String::new());
+    let c = || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t) = (t);
+        let _t = t.0;
+        println!("{}", t1.1);
+    };
+
+    c();
+}
+
+// Copy types get copied into the closure instead of move. Therefore we don't need to
+// migrate then as their drop order isn't tied to the closure.
+fn test4_only_non_copy_types_need_migration() {
+    let t = (String::new(), String::new());
+
+    // `t1` is Copy because all of its elements are Copy
+    let t1 = (0i32, 0i32);
+
+    let c = || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t) = (t);
+        let _t = t.0;
+        let _t1 = t1.0;
+    };
+
+    c();
+}
+
+fn test5_only_drop_types_need_migration() {
+    struct S(i32, i32);
+
+    let t = (String::new(), String::new());
+
+    // `s` doesn't implement Drop or any elements within it, and doesn't need migration
+    let s = S(0i32, 0i32);
+
+    let c = || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t) = (t);
+        let _t = t.0;
+        let _s = s.0;
+    };
+
+    c();
+}
+
+// Since we are using a move closure here, both `t` and `t1` get moved
+// even though they are being used by ref inside the closure.
+fn test6_move_closures_non_copy_types_might_need_migration() {
+    let t = (String::new(), String::new());
+    let t1 = (String::new(), String::new());
+    let c = move || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t1, t) = (t1, t);
+        println!("{} {}", t1.1, t.1);
+    };
+
+    c();
+}
+
+// Test migration analysis in case of Drop + Non Drop aggregates.
+// Note we need migration here only because the non-copy (because Drop type) is captured,
+// otherwise we won't need to, since we can get away with just by ref capture in that case.
+fn test7_drop_non_drop_aggregate_need_migration() {
+    let t = (String::new(), 0i32);
+
+    let c = || {
+    //~^ERROR: Drop order affected for closure because of `capture_disjoint_fields`
+    //~| NOTE: let (t) = (t);
+        let _t = t.0;
+    };
+
+    c();
+}
+
+fn main() {
+    test1_all_need_migration();
+    test2_only_precise_paths_need_migration();
+    test3_only_by_value_need_migration();
+    test4_only_non_copy_types_need_migration();
+    test5_only_drop_types_need_migration();
+    test6_move_closures_non_copy_types_might_need_migration();
+    test7_drop_non_drop_aggregate_need_migration();
+}

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop.stderr

@@ -0,0 +1,105 @@
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:13:13
+   |
+LL |       let c = || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         let _t = t.0;
+LL | |         let _t1 = t1.0;
+LL | |         let _t2 = t2.0;
+LL | |     };
+   | |_____^
+   |
+note: the lint level is defined here
+  --> $DIR/insignificant_drop.rs:1:9
+   |
+LL | #![deny(disjoint_capture_drop_reorder)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: let (t, t1, t2) = (t, t1, t2);
+
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:31:13
+   |
+LL |       let c = || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         let _t = t.0;
+LL | |         let _t1 = t1.0;
+LL | |         let _t2 = t2;
+LL | |     };
+   | |_____^
+   |
+   = note: let (t, t1) = (t, t1);
+
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:47:13
+   |
+LL |       let c = || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         let _t = t.0;
+LL | |         println!("{}", t1.1);
+LL | |     };
+   | |_____^
+   |
+   = note: let (t) = (t);
+
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:65:13
+   |
+LL |       let c = || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         let _t = t.0;
+LL | |         let _t1 = t1.0;
+LL | |     };
+   | |_____^
+   |
+   = note: let (t) = (t);
+
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:83:13
+   |
+LL |       let c = || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         let _t = t.0;
+LL | |         let _s = s.0;
+LL | |     };
+   | |_____^
+   |
+   = note: let (t) = (t);
+
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:98:13
+   |
+LL |       let c = move || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         println!("{} {}", t1.1, t.1);
+LL | |     };
+   | |_____^
+   |
+   = note: let (t1, t) = (t1, t);
+
+error: Drop order affected for closure because of `capture_disjoint_fields`
+  --> $DIR/insignificant_drop.rs:113:13
+   |
+LL |       let c = || {
+   |  _____________^
+LL | |
+LL | |
+LL | |         let _t = t.0;
+LL | |     };
+   | |_____^
+   |
+   = note: let (t) = (t);
+
+error: aborting due to 7 previous errors
+

src/test/ui/closures/2229_closure_analysis/migrations/no_migrations.rs

@@ -0,0 +1,84 @@
+// run-pass
+
+// Set of test cases that don't need migrations
+
+#![deny(disjoint_capture_drop_reorder)]
+
+
+// Copy types as copied by the closure instead of being moved into the closure
+// Therefore their drop order isn't tied to the closure and won't be requiring any
+// migrations.
+fn test1_only_copy_types() {
+    let t = (0i32, 0i32);
+
+    let c = || {
+        let _t = t.0;
+    };
+
+    c();
+}
+
+// Same as test1 but using a move closure
+fn test2_only_copy_types_move_closure() {
+    let t = (0i32, 0i32);
+
+    let c = move || {
+        println!("{}", t.0);
+    };
+
+    c();
+}
+
+// Don't need to migrate if captured by ref
+fn test3_only_copy_types_move_closure() {
+    let t = (String::new(), String::new());
+
+    let c = || {
+        println!("{}", t.0);
+    };
+
+    c();
+}
+
+// Test migration analysis in case of Insignificant Drop + Non Drop aggregates.
+// Note in this test the closure captures a non Drop type and therefore the variable
+// is only captured by ref.
+fn test4_insignificant_drop_non_drop_aggregate() {
+    let t = (String::new(), 0i32);
+
+    let c = || {
+        let _t = t.1;
+    };
+
+    c();
+}
+
+
+struct Foo(i32);
+impl Drop for Foo {
+    fn drop(&mut self) {
+        println!("{:?} dropped", self.0);
+    }
+}
+
+// Test migration analysis in case of Significant Drop + Non Drop aggregates.
+// Note in this test the closure captures a non Drop type and therefore the variable
+// is only captured by ref.
+fn test5_significant_drop_non_drop_aggregate() {
+    let t = (Foo(0), 0i32);
+
+    let c = || {
+        let _t = t.1;
+    };
+
+    c();
+}
+
+fn main() {
+    test1_only_copy_types();
+    test2_only_copy_types_move_closure();
+    test3_only_copy_types_move_closure();
+    test4_insignificant_drop_non_drop_aggregate();
+    test5_significant_drop_non_drop_aggregate();
+
+}