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Diffstat (limited to '')
-rw-r--r-- | src/test/mir-opt/issue-41697.rs | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/test/mir-opt/issue-41697.rs b/src/test/mir-opt/issue-41697.rs new file mode 100644 index 000000000..5c34d8e68 --- /dev/null +++ b/src/test/mir-opt/issue-41697.rs @@ -0,0 +1,40 @@ +// Regression test for #41697. Using dump-mir was triggering +// artificial cycles: during type-checking, we had to get the MIR for +// the constant expressions in `[u8; 2]`, which in turn would trigger +// an attempt to get the def-path, which in turn would request the +// types of the impl, which would trigger a cycle. We suppressed this +// cycle now by forcing mir-dump to avoid asking for types of an impl. + +#![feature(rustc_attrs)] + +use std::sync::Arc; + +trait Foo { + fn get(&self) -> [u8; 2]; +} + +// EMIT_MIR_FOR_EACH_BIT_WIDTH +// EMIT_MIR issue_41697.{impl#0}-{constant#0}.SimplifyCfg-promote-consts.after.mir +impl Foo for [u8; 1+1] { + fn get(&self) -> [u8; 2] { + *self + } +} + +struct Bar<T: ?Sized>(T); + +fn unsize_fat_ptr<'a>(x: &'a Bar<Foo + Send + 'a>) -> &'a Bar<Foo + 'a> { + x +} + +fn unsize_nested_fat_ptr(x: Arc<Foo + Send>) -> Arc<Foo> { + x +} + +fn main() { + let x: Box<Bar<Foo + Send>> = Box::new(Bar([1,2])); + assert_eq!(unsize_fat_ptr(&*x).0.get(), [1, 2]); + + let x: Arc<Foo + Send> = Arc::new([3, 4]); + assert_eq!(unsize_nested_fat_ptr(x).get(), [3, 4]); +} |