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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/dropck/dropck-eyepatch-reorder.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/dropck/dropck-eyepatch-reorder.rs')
-rw-r--r-- | tests/ui/dropck/dropck-eyepatch-reorder.rs | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/tests/ui/dropck/dropck-eyepatch-reorder.rs b/tests/ui/dropck/dropck-eyepatch-reorder.rs new file mode 100644 index 000000000..44552b3fc --- /dev/null +++ b/tests/ui/dropck/dropck-eyepatch-reorder.rs @@ -0,0 +1,100 @@ +#![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) { } |