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 --- tests/ui/lint/dead-code/self-assign.rs | 52 ++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 tests/ui/lint/dead-code/self-assign.rs (limited to 'tests/ui/lint/dead-code/self-assign.rs') diff --git a/tests/ui/lint/dead-code/self-assign.rs b/tests/ui/lint/dead-code/self-assign.rs new file mode 100644 index 000000000..ea7ce98d8 --- /dev/null +++ b/tests/ui/lint/dead-code/self-assign.rs @@ -0,0 +1,52 @@ +// Test that dead code warnings are issued for superfluous assignments of +// fields or variables to themselves (issue #75356). + +// ignore-test FIXME(81658, 83171) + +// check-pass +#![allow(unused_assignments)] +#![warn(dead_code)] + +fn main() { + let mut x = 0; + x = x; + //~^ WARNING: useless assignment of variable of type `i32` to itself + + x = (x); + //~^ WARNING: useless assignment of variable of type `i32` to itself + + x = {x}; + // block expressions don't count as self-assignments + + + struct S<'a> { f: &'a str } + let mut s = S { f: "abc" }; + s = s; + //~^ WARNING: useless assignment of variable of type `S` to itself + + s.f = s.f; + //~^ WARNING: useless assignment of field of type `&str` to itself + + + struct N0 { x: Box } + struct N1 { n: N0 } + struct N2(N1); + struct N3 { n: N2 }; + let mut n3 = N3 { n: N2(N1 { n: N0 { x: Box::new(42) } }) }; + n3.n.0.n.x = n3.n.0.n.x; + //~^ WARNING: useless assignment of field of type `Box` to itself + + let mut t = (1, ((2, 3, (4, 5)),)); + t.1.0.2.1 = t.1.0.2.1; + //~^ WARNING: useless assignment of field of type `i32` to itself + + + let mut y = 0; + macro_rules! assign_to_y { + ($cur:expr) => {{ + y = $cur; + }}; + } + assign_to_y!(y); + // self-assignments in macro expansions are not reported either +} -- cgit v1.2.3