diff options
Diffstat (limited to 'src/test/ui-fulldeps/dropck-tarena-cycle-checked.rs')
-rw-r--r-- | src/test/ui-fulldeps/dropck-tarena-cycle-checked.rs | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/test/ui-fulldeps/dropck-tarena-cycle-checked.rs b/src/test/ui-fulldeps/dropck-tarena-cycle-checked.rs new file mode 100644 index 000000000..cc97971a0 --- /dev/null +++ b/src/test/ui-fulldeps/dropck-tarena-cycle-checked.rs @@ -0,0 +1,117 @@ +// Reject mixing cyclic structure and Drop when using TypedArena. +// +// (Compare against dropck-vec-cycle-checked.rs) +// +// (Also compare against ui-fulldeps/dropck-tarena-unsound-drop.rs, +// which is a reduction of this code to more directly show the reason +// for the error message we see here.) + +#![feature(rustc_private)] + +extern crate rustc_arena; + +use rustc_arena::TypedArena; +use std::cell::Cell; +use id::Id; + +mod s { + use std::sync::atomic::{AtomicUsize, Ordering}; + + static S_COUNT: AtomicUsize = AtomicUsize::new(0); + + pub fn next_count() -> usize { + S_COUNT.fetch_add(1, Ordering::SeqCst) + 1 + } +} + +mod id { + use s; + #[derive(Debug)] + pub struct Id { + orig_count: usize, + count: usize, + } + + impl Id { + pub fn new() -> Id { + let c = s::next_count(); + println!("building Id {}", c); + Id { orig_count: c, count: c } + } + pub fn count(&self) -> usize { + println!("Id::count on {} returns {}", self.orig_count, self.count); + self.count + } + } + + impl Drop for Id { + fn drop(&mut self) { + println!("dropping Id {}", self.count); + self.count = 0; + } + } +} + +trait HasId { + fn count(&self) -> usize; +} + +#[derive(Debug)] +struct CheckId<T:HasId> { + v: T +} + +#[allow(non_snake_case)] +fn CheckId<T:HasId>(t: T) -> CheckId<T> { CheckId{ v: t } } + +impl<T:HasId> Drop for CheckId<T> { + fn drop(&mut self) { + assert!(self.v.count() > 0); + } +} + +#[derive(Debug)] +struct C<'a> { + id: Id, + v: Vec<CheckId<Cell<Option<&'a C<'a>>>>>, +} + +impl<'a> HasId for Cell<Option<&'a C<'a>>> { + fn count(&self) -> usize { + match self.get() { + None => 1, + Some(c) => c.id.count(), + } + } +} + +impl<'a> C<'a> { + fn new() -> C<'a> { + C { id: Id::new(), v: Vec::new() } + } +} + +fn f<'a>(arena: &'a TypedArena<C<'a>>) { + let c1 = arena.alloc(C::new()); + let c2 = arena.alloc(C::new()); + let c3 = arena.alloc(C::new()); + + c1.v.push(CheckId(Cell::new(None))); + c1.v.push(CheckId(Cell::new(None))); + c2.v.push(CheckId(Cell::new(None))); + c2.v.push(CheckId(Cell::new(None))); + c3.v.push(CheckId(Cell::new(None))); + c3.v.push(CheckId(Cell::new(None))); + + c1.v[0].v.set(Some(c2)); + c1.v[1].v.set(Some(c3)); + c2.v[0].v.set(Some(c2)); + c2.v[1].v.set(Some(c3)); + c3.v[0].v.set(Some(c1)); + c3.v[1].v.set(Some(c2)); +} + +fn main() { + let arena = TypedArena::default(); + f(&arena); +} //~^ ERROR `arena` does not live long enough |