diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs index b85a987c641..279729365ee 100644 --- a/compiler/rustc_passes/src/liveness.rs +++ b/compiler/rustc_passes/src/liveness.rs @@ -1521,6 +1521,14 @@ impl<'tcx> Liveness<'_, 'tcx> { } fn warn_about_unused_args(&self, body: &hir::Body<'_>, entry_ln: LiveNode) { + if let Some(intrinsic) = + self.ir.tcx.intrinsic(self.ir.tcx.hir().body_owner_def_id(body.id())) + { + if intrinsic.must_be_overridden { + return; + } + } + for p in body.params { self.check_unused_vars_in_pat( p.pat, diff --git a/tests/ui/liveness/liveness-unused.rs b/tests/ui/liveness/liveness-unused.rs index ba635e6638c..49e7044aeda 100644 --- a/tests/ui/liveness/liveness-unused.rs +++ b/tests/ui/liveness/liveness-unused.rs @@ -2,6 +2,7 @@ #![deny(unused_variables)] #![deny(unused_assignments)] #![allow(dead_code, non_camel_case_types, trivial_numeric_casts, dropping_copy_types)] +#![feature(intrinsics)] use std::ops::AddAssign; @@ -137,5 +138,10 @@ fn f7() { drop(a); } +// unused params warnings are not needed for intrinsic functions without bodies +#[rustc_intrinsic] +unsafe fn simd_shuffle<T, I, U>(a: T, b: T, i: I) -> U; + + fn main() { } diff --git a/tests/ui/liveness/liveness-unused.stderr b/tests/ui/liveness/liveness-unused.stderr index f6c478ddbc7..a69fc10dff2 100644 --- a/tests/ui/liveness/liveness-unused.stderr +++ b/tests/ui/liveness/liveness-unused.stderr @@ -1,5 +1,5 @@ warning: unreachable statement - --> $DIR/liveness-unused.rs:92:9 + --> $DIR/liveness-unused.rs:93:9 | LL | continue; | -------- any code following this expression is unreachable @@ -14,7 +14,7 @@ LL | #![warn(unused)] = note: `#[warn(unreachable_code)]` implied by `#[warn(unused)]` error: unused variable: `x` - --> $DIR/liveness-unused.rs:8:7 + --> $DIR/liveness-unused.rs:9:7 | LL | fn f1(x: isize) { | ^ help: if this is intentional, prefix it with an underscore: `_x` @@ -26,25 +26,25 @@ LL | #![deny(unused_variables)] | ^^^^^^^^^^^^^^^^ error: unused variable: `x` - --> $DIR/liveness-unused.rs:12:8 + --> $DIR/liveness-unused.rs:13:8 | LL | fn f1b(x: &mut isize) { | ^ help: if this is intentional, prefix it with an underscore: `_x` error: unused variable: `x` - --> $DIR/liveness-unused.rs:20:9 + --> $DIR/liveness-unused.rs:21:9 | LL | let x: isize; | ^ help: if this is intentional, prefix it with an underscore: `_x` error: unused variable: `x` - --> $DIR/liveness-unused.rs:25:9 + --> $DIR/liveness-unused.rs:26:9 | LL | let x = 3; | ^ help: if this is intentional, prefix it with an underscore: `_x` error: variable `x` is assigned to, but never used - --> $DIR/liveness-unused.rs:30:13 + --> $DIR/liveness-unused.rs:31:13 | LL | let mut x = 3; | ^ @@ -52,7 +52,7 @@ LL | let mut x = 3; = note: consider using `_x` instead error: value assigned to `x` is never read - --> $DIR/liveness-unused.rs:32:5 + --> $DIR/liveness-unused.rs:33:5 | LL | x += 4; | ^ @@ -65,7 +65,7 @@ LL | #![deny(unused_assignments)] | ^^^^^^^^^^^^^^^^^^ error: variable `z` is assigned to, but never used - --> $DIR/liveness-unused.rs:37:13 + --> $DIR/liveness-unused.rs:38:13 | LL | let mut z = 3; | ^ @@ -73,31 +73,31 @@ LL | let mut z = 3; = note: consider using `_z` instead error: unused variable: `i` - --> $DIR/liveness-unused.rs:59:12 + --> $DIR/liveness-unused.rs:60:12 | LL | Some(i) => { | ^ help: if this is intentional, prefix it with an underscore: `_i` error: unused variable: `x` - --> $DIR/liveness-unused.rs:79:9 + --> $DIR/liveness-unused.rs:80:9 | LL | for x in 1..10 { } | ^ help: if this is intentional, prefix it with an underscore: `_x` error: unused variable: `x` - --> $DIR/liveness-unused.rs:84:10 + --> $DIR/liveness-unused.rs:85:10 | LL | for (x, _) in [1, 2, 3].iter().enumerate() { } | ^ help: if this is intentional, prefix it with an underscore: `_x` error: unused variable: `x` - --> $DIR/liveness-unused.rs:89:13 + --> $DIR/liveness-unused.rs:90:13 | LL | for (_, x) in [1, 2, 3].iter().enumerate() { | ^ help: if this is intentional, prefix it with an underscore: `_x` error: variable `x` is assigned to, but never used - --> $DIR/liveness-unused.rs:112:9 + --> $DIR/liveness-unused.rs:113:9 | LL | let x; | ^ @@ -105,7 +105,7 @@ LL | let x; = note: consider using `_x` instead error: value assigned to `x` is never read - --> $DIR/liveness-unused.rs:116:9 + --> $DIR/liveness-unused.rs:117:9 | LL | x = 0; | ^