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-rw-r--r--src/test/ui/dropck/dropck-eyepatch-reorder.rs100
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diff --git a/src/test/ui/dropck/dropck-eyepatch-reorder.rs b/src/test/ui/dropck/dropck-eyepatch-reorder.rs
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+++ b/src/test/ui/dropck/dropck-eyepatch-reorder.rs
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+#![feature(dropck_eyepatch)]
+
+// The point of this test is to test uses of `#[may_dangle]` attribute
+// where the formal declaration order (in the impl generics) does not
+// match the actual usage order (in the type instantiation).
+//
+// See also dropck-eyepatch.rs for more information about the general
+// structure of the test.
+
+use std::fmt;
+
+struct Dt<A: fmt::Debug>(&'static str, A);
+struct Dr<'a, B:'a+fmt::Debug>(&'static str, &'a B);
+struct Pt<A: fmt::Debug, B: fmt::Debug>(&'static str, A, B);
+struct Pr<'a, 'b, B:'a+'b+fmt::Debug>(&'static str, &'a B, &'b B);
+struct St<A: fmt::Debug>(&'static str, A);
+struct Sr<'a, B:'a+fmt::Debug>(&'static str, &'a B);
+
+impl<A: fmt::Debug> Drop for Dt<A> {
+ fn drop(&mut self) { println!("drop {} {:?}", self.0, self.1); }
+}
+impl<'a, B: fmt::Debug> Drop for Dr<'a, B> {
+ fn drop(&mut self) { println!("drop {} {:?}", self.0, self.1); }
+}
+unsafe impl<B: fmt::Debug, #[may_dangle] A: fmt::Debug> Drop for Pt<A, B> {
+ // (unsafe to access self.1 due to #[may_dangle] on A)
+ fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); }
+}
+unsafe impl<'b, #[may_dangle] 'a, B: fmt::Debug> Drop for Pr<'a, 'b, B> {
+ // (unsafe to access self.1 due to #[may_dangle] on 'a)
+ fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); }
+}
+
+fn main() {
+ use std::cell::Cell;
+
+ // We use separate blocks with separate variable to prevent the error
+ // messages from being deduplicated.
+
+ {
+ let c_long;
+ let (mut dt, mut dr): (Dt<_>, Dr<_>);
+ c_long = Cell::new(1);
+
+ // No error: sufficiently long-lived state can be referenced in dtors
+ dt = Dt("dt", &c_long);
+ dr = Dr("dr", &c_long);
+ }
+
+ {
+ let (c, mut dt, mut dr): (Cell<_>, Dt<_>, Dr<_>);
+ c = Cell::new(1);
+
+ // No Error: destructor order precisely modelled
+ dt = Dt("dt", &c);
+ dr = Dr("dr", &c);
+ }
+
+ {
+ let (mut dt, mut dr, c_shortest): (Dt<_>, Dr<_>, Cell<_>);
+ c_shortest = Cell::new(1);
+
+ // Error: `c_shortest` dies too soon for the references in dtors to be valid.
+ dt = Dt("dt", &c_shortest);
+ //~^ ERROR `c_shortest` does not live long enough
+ dr = Dr("dr", &c_shortest);
+ }
+
+ {
+ let c_long;
+ let (mut pt, mut pr, c_shortest): (Pt<_, _>, Pr<_>, Cell<_>);
+ c_long = Cell::new(1);
+ c_shortest = Cell::new(1);
+
+ // No error: Drop impl asserts .1 (A and &'a _) are not accessed
+ pt = Pt("pt", &c_shortest, &c_long);
+ pr = Pr("pr", &c_shortest, &c_long);
+ }
+
+ {
+ let c_long;
+ let (mut pt, mut pr, c_shortest): (Pt<_, _>, Pr<_>, Cell<_>);
+ c_long = Cell::new(1);
+ c_shortest = Cell::new(1);
+ // Error: Drop impl's assertion does not apply to `B` nor `&'b _`
+ pt = Pt("pt", &c_long, &c_shortest);
+ //~^ ERROR `c_shortest` does not live long enough
+ pr = Pr("pr", &c_long, &c_shortest);
+ }
+
+ {
+ let (st, sr, c_shortest): (St<_>, Sr<_>, Cell<_>);
+ c_shortest = Cell::new(1);
+ // No error: St and Sr have no destructor.
+ st = St("st", &c_shortest);
+ sr = Sr("sr", &c_shortest);
+ }
+}
+
+fn use_imm<T>(_: &T) { }