From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:13 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- src/test/ui/dropck/dropck-eyepatch.rs | 123 ---------------------------------- 1 file changed, 123 deletions(-) delete mode 100644 src/test/ui/dropck/dropck-eyepatch.rs (limited to 'src/test/ui/dropck/dropck-eyepatch.rs') diff --git a/src/test/ui/dropck/dropck-eyepatch.rs b/src/test/ui/dropck/dropck-eyepatch.rs deleted file mode 100644 index ec1c68561..000000000 --- a/src/test/ui/dropck/dropck-eyepatch.rs +++ /dev/null @@ -1,123 +0,0 @@ -#![feature(dropck_eyepatch)] - -// The point of this test is to illustrate that the `#[may_dangle]` -// attribute specifically allows, in the context of a type -// implementing `Drop`, a generic parameter to be instantiated with a -// lifetime that does not strictly outlive the owning type itself. -// -// Here we test that only the expected errors are issued. -// -// The illustration is made concrete by comparison with two variations -// on the type with `#[may_dangle]`: -// -// 1. an analogous type that does not implement `Drop` (and thus -// should exhibit maximal flexibility with respect to dropck), and -// -// 2. an analogous type that does not use `#[may_dangle]` (and thus -// should exhibit the standard limitations imposed by dropck. -// -// The types in this file follow a pattern, {D,P,S}{t,r}, where: -// -// - D means "I implement Drop" -// -// - P means "I implement Drop but guarantee my (first) parameter is -// pure, i.e., not accessed from the destructor"; no other parameters -// are pure. -// -// - S means "I do not implement Drop" -// -// - t suffix is used when the first generic is a type -// -// - r suffix is used when the first generic is a lifetime. - -use std::fmt; - -struct Dt(&'static str, A); -struct Dr<'a, B:'a+fmt::Debug>(&'static str, &'a B); -struct Pt(&'static str, A, B); -struct Pr<'a, 'b, B:'a+'b+fmt::Debug>(&'static str, &'a B, &'b B); -struct St(&'static str, A); -struct Sr<'a, B:'a+fmt::Debug>(&'static str, &'a B); - -impl Drop for Dt { - 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<#[may_dangle] A, B: fmt::Debug> Drop for Pt { - // (unsafe to access self.1 due to #[may_dangle] on A) - fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); } -} -unsafe impl<#[may_dangle] 'a, 'b, 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) { } -- cgit v1.2.3