diff options
Diffstat (limited to 'tests/ui/mir-dataflow/liveness-projection.rs')
-rw-r--r-- | tests/ui/mir-dataflow/liveness-projection.rs | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/tests/ui/mir-dataflow/liveness-projection.rs b/tests/ui/mir-dataflow/liveness-projection.rs new file mode 100644 index 000000000..486f31b63 --- /dev/null +++ b/tests/ui/mir-dataflow/liveness-projection.rs @@ -0,0 +1,32 @@ +#![feature(core_intrinsics, rustc_attrs)] + +use std::intrinsics::rustc_peek; + +#[rustc_mir(rustc_peek_liveness, stop_after_dataflow)] +fn foo() { + { + let mut x: (i32, i32) = (42, 0); + + // Assignment to a projection does not cause `x` to become live + unsafe { rustc_peek(x); } //~ ERROR bit not set + x.1 = 42; + + x = (0, 42); + + // ...but a read from a projection does. + unsafe { rustc_peek(x); } + println!("{}", x.1); + } + + { + let mut x = 42; + + // Derefs are treated like a read of a local even if they are on the LHS of an assignment. + let p = &mut x; + unsafe { rustc_peek(&p); } + *p = 24; + unsafe { rustc_peek(&p); } //~ ERROR bit not set + } +} + +fn main() {} |