From f5c6c9542ecfab74e654f9b7f1150d486560ae43 Mon Sep 17 00:00:00 2001 From: Caleb Zulawski Date: Tue, 16 Sep 2025 02:23:24 -0400 Subject: Add an attribute to check the number of lanes in a SIMD vector after monomorphization Unify zero-length and oversized SIMD errors --- tests/ui/simd/auxiliary/simd-lane-limit.rs | 5 +++++ tests/ui/simd/monomorphize-too-long.rs | 4 +--- tests/ui/simd/monomorphize-too-long.stderr | 6 +++++- tests/ui/simd/monomorphize-zero-length.rs | 4 +--- tests/ui/simd/monomorphize-zero-length.stderr | 6 +++++- tests/ui/simd/simd-lane-limit-err-npow2.rs | 12 ++++++++++++ tests/ui/simd/simd-lane-limit-err-npow2.stderr | 8 ++++++++ tests/ui/simd/simd-lane-limit-err.rs | 11 +++++++++++ tests/ui/simd/simd-lane-limit-err.stderr | 8 ++++++++ tests/ui/simd/simd-lane-limit-ok.rs | 14 ++++++++++++++ tests/ui/simd/type-generic-monomorphisation-empty.rs | 4 +--- tests/ui/simd/type-generic-monomorphisation-empty.stderr | 6 +++++- tests/ui/simd/type-generic-monomorphisation-oversized.rs | 5 ++--- .../ui/simd/type-generic-monomorphisation-oversized.stderr | 6 +++++- 14 files changed, 83 insertions(+), 16 deletions(-) create mode 100644 tests/ui/simd/auxiliary/simd-lane-limit.rs create mode 100644 tests/ui/simd/simd-lane-limit-err-npow2.rs create mode 100644 tests/ui/simd/simd-lane-limit-err-npow2.stderr create mode 100644 tests/ui/simd/simd-lane-limit-err.rs create mode 100644 tests/ui/simd/simd-lane-limit-err.stderr create mode 100644 tests/ui/simd/simd-lane-limit-ok.rs (limited to 'tests/ui') diff --git a/tests/ui/simd/auxiliary/simd-lane-limit.rs b/tests/ui/simd/auxiliary/simd-lane-limit.rs new file mode 100644 index 00000000000..dde6b880c62 --- /dev/null +++ b/tests/ui/simd/auxiliary/simd-lane-limit.rs @@ -0,0 +1,5 @@ +#![feature(rustc_attrs, repr_simd)] + +#[repr(simd, packed)] +#[rustc_simd_monomorphize_lane_limit = "8"] +pub struct Simd(pub [T; N]); diff --git a/tests/ui/simd/monomorphize-too-long.rs b/tests/ui/simd/monomorphize-too-long.rs index 4fac987b0b5..9c837415191 100644 --- a/tests/ui/simd/monomorphize-too-long.rs +++ b/tests/ui/simd/monomorphize-too-long.rs @@ -6,7 +6,5 @@ struct Simd([T; N]); fn main() { - let _too_big = Simd([1_u16; 54321]); + let _too_big = Simd([1_u16; 54321]); //~ ERROR the SIMD type `Simd` has more elements than the limit 32768 } - -//~? ERROR monomorphising SIMD type `Simd` of length greater than 32768 diff --git a/tests/ui/simd/monomorphize-too-long.stderr b/tests/ui/simd/monomorphize-too-long.stderr index 978eef307ab..71bc78ef5c9 100644 --- a/tests/ui/simd/monomorphize-too-long.stderr +++ b/tests/ui/simd/monomorphize-too-long.stderr @@ -1,4 +1,8 @@ -error: monomorphising SIMD type `Simd` of length greater than 32768 +error: the SIMD type `Simd` has more elements than the limit 32768 + --> $DIR/monomorphize-too-long.rs:9:9 + | +LL | let _too_big = Simd([1_u16; 54321]); + | ^^^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/simd/monomorphize-zero-length.rs b/tests/ui/simd/monomorphize-zero-length.rs index d38870c572d..f956197a61c 100644 --- a/tests/ui/simd/monomorphize-zero-length.rs +++ b/tests/ui/simd/monomorphize-zero-length.rs @@ -6,7 +6,5 @@ struct Simd([T; N]); fn main() { - let _empty = Simd([1.0; 0]); + let _empty = Simd([1.0; 0]); //~ ERROR the SIMD type `Simd` has zero elements } - -//~? ERROR monomorphising SIMD type `Simd` of zero length diff --git a/tests/ui/simd/monomorphize-zero-length.stderr b/tests/ui/simd/monomorphize-zero-length.stderr index 738c20fe51a..66f26d95c9d 100644 --- a/tests/ui/simd/monomorphize-zero-length.stderr +++ b/tests/ui/simd/monomorphize-zero-length.stderr @@ -1,4 +1,8 @@ -error: monomorphising SIMD type `Simd` of zero length +error: the SIMD type `Simd` has zero elements + --> $DIR/monomorphize-zero-length.rs:9:9 + | +LL | let _empty = Simd([1.0; 0]); + | ^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/simd/simd-lane-limit-err-npow2.rs b/tests/ui/simd/simd-lane-limit-err-npow2.rs new file mode 100644 index 00000000000..d5c5c92e953 --- /dev/null +++ b/tests/ui/simd/simd-lane-limit-err-npow2.rs @@ -0,0 +1,12 @@ +//@ build-fail +//@ aux-crate:simd=simd-lane-limit.rs + +extern crate simd; + +use simd::Simd; + +fn main() { + // test non-power-of-two, since #[repr(simd, packed)] has unusual layout + let _x: Simd = Simd([0; 24]); + //~^ ERROR the SIMD type `simd::Simd` has more elements than the limit 8 +} diff --git a/tests/ui/simd/simd-lane-limit-err-npow2.stderr b/tests/ui/simd/simd-lane-limit-err-npow2.stderr new file mode 100644 index 00000000000..fff26c4c1c1 --- /dev/null +++ b/tests/ui/simd/simd-lane-limit-err-npow2.stderr @@ -0,0 +1,8 @@ +error: the SIMD type `simd::Simd` has more elements than the limit 8 + --> $DIR/simd-lane-limit-err-npow2.rs:10:9 + | +LL | let _x: Simd = Simd([0; 24]); + | ^^ + +error: aborting due to 1 previous error + diff --git a/tests/ui/simd/simd-lane-limit-err.rs b/tests/ui/simd/simd-lane-limit-err.rs new file mode 100644 index 00000000000..00390bdbdaf --- /dev/null +++ b/tests/ui/simd/simd-lane-limit-err.rs @@ -0,0 +1,11 @@ +//@ build-fail +//@ aux-crate:simd=simd-lane-limit.rs + +extern crate simd; + +use simd::Simd; + +fn main() { + let _x: Simd = Simd([0; 16]); + //~^ ERROR the SIMD type `simd::Simd` has more elements than the limit 8 +} diff --git a/tests/ui/simd/simd-lane-limit-err.stderr b/tests/ui/simd/simd-lane-limit-err.stderr new file mode 100644 index 00000000000..3f2eaeda2d4 --- /dev/null +++ b/tests/ui/simd/simd-lane-limit-err.stderr @@ -0,0 +1,8 @@ +error: the SIMD type `simd::Simd` has more elements than the limit 8 + --> $DIR/simd-lane-limit-err.rs:9:9 + | +LL | let _x: Simd = Simd([0; 16]); + | ^^ + +error: aborting due to 1 previous error + diff --git a/tests/ui/simd/simd-lane-limit-ok.rs b/tests/ui/simd/simd-lane-limit-ok.rs new file mode 100644 index 00000000000..52fd3158440 --- /dev/null +++ b/tests/ui/simd/simd-lane-limit-ok.rs @@ -0,0 +1,14 @@ +//@ build-pass +//@ aux-crate:simd=simd-lane-limit.rs + +extern crate simd; + +use simd::Simd; + +fn main() { + let _x: Simd = Simd([0; 4]); + let _y: Simd = Simd([0; 8]); + + // test non-power-of-two, since #[repr(simd, packed)] has unusual layout + let _z: Simd = Simd([0; 6]); +} diff --git a/tests/ui/simd/type-generic-monomorphisation-empty.rs b/tests/ui/simd/type-generic-monomorphisation-empty.rs index c08dc9fe3df..7c43b8914da 100644 --- a/tests/ui/simd/type-generic-monomorphisation-empty.rs +++ b/tests/ui/simd/type-generic-monomorphisation-empty.rs @@ -6,7 +6,5 @@ struct Simd([f32; N]); fn main() { - let _ = Simd::<0>([]); + let _empty = Simd::<0>([]); //~ ERROR the SIMD type `Simd<0>` has zero elements } - -//~? ERROR monomorphising SIMD type `Simd<0>` of zero length diff --git a/tests/ui/simd/type-generic-monomorphisation-empty.stderr b/tests/ui/simd/type-generic-monomorphisation-empty.stderr index fc294607ae3..450db7e47db 100644 --- a/tests/ui/simd/type-generic-monomorphisation-empty.stderr +++ b/tests/ui/simd/type-generic-monomorphisation-empty.stderr @@ -1,4 +1,8 @@ -error: monomorphising SIMD type `Simd<0>` of zero length +error: the SIMD type `Simd<0>` has zero elements + --> $DIR/type-generic-monomorphisation-empty.rs:9:9 + | +LL | let _empty = Simd::<0>([]); + | ^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/simd/type-generic-monomorphisation-oversized.rs b/tests/ui/simd/type-generic-monomorphisation-oversized.rs index efe3480317c..73a1f00e8c7 100644 --- a/tests/ui/simd/type-generic-monomorphisation-oversized.rs +++ b/tests/ui/simd/type-generic-monomorphisation-oversized.rs @@ -6,7 +6,6 @@ struct Simd([f32; N]); fn main() { - let _ = Simd::<65536>([0.; 65536]); + let _x = Simd::<65536>([0.; 65536]); + //~^ ERROR the SIMD type `Simd<65536>` has more elements than the limit 32768 } - -//~? ERROR monomorphising SIMD type `Simd<65536>` of length greater than 32768 diff --git a/tests/ui/simd/type-generic-monomorphisation-oversized.stderr b/tests/ui/simd/type-generic-monomorphisation-oversized.stderr index 39ff36799cc..0065049abd6 100644 --- a/tests/ui/simd/type-generic-monomorphisation-oversized.stderr +++ b/tests/ui/simd/type-generic-monomorphisation-oversized.stderr @@ -1,4 +1,8 @@ -error: monomorphising SIMD type `Simd<65536>` of length greater than 32768 +error: the SIMD type `Simd<65536>` has more elements than the limit 32768 + --> $DIR/type-generic-monomorphisation-oversized.rs:9:9 + | +LL | let _x = Simd::<65536>([0.; 65536]); + | ^^ error: aborting due to 1 previous error -- cgit 1.4.1-3-g733a5 From a86f14072714fb817a6f60fa20be5a4e875d049f Mon Sep 17 00:00:00 2001 From: Ding Xiang Fei Date: Tue, 12 Aug 2025 06:39:50 +0800 Subject: do not materialise X in [X; 0] when X is unsizing a const --- .../rustc_mir_build/src/builder/expr/as_rvalue.rs | 21 ++++++++++++++- .../no_local_for_coerced_const-issue-143671.rs | 30 ++++++++++++++++++++++ 2 files changed, 50 insertions(+), 1 deletion(-) create mode 100644 tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs (limited to 'tests/ui') diff --git a/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs index a4ef6e92739..d6dc12e5955 100644 --- a/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs +++ b/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs @@ -8,6 +8,7 @@ use rustc_middle::middle::region; use rustc_middle::mir::interpret::Scalar; use rustc_middle::mir::*; use rustc_middle::thir::*; +use rustc_middle::ty::adjustment::PointerCoercion; use rustc_middle::ty::cast::{CastTy, mir_cast_kind}; use rustc_middle::ty::util::IntTypeExt; use rustc_middle::ty::{self, Ty, UpvarArgs}; @@ -656,6 +657,24 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block.and(rvalue) } + /// Recursively inspect a THIR expression and probe through unsizing + /// operations that can be const-folded today. + fn check_constness(&self, mut kind: &'a ExprKind<'tcx>) -> bool { + loop { + match kind { + &ExprKind::PointerCoercion { + cast: PointerCoercion::Unsize, + source: eid, + is_from_as_cast: _, + } + | &ExprKind::Scope { region_scope: _, lint_level: _, value: eid } => { + kind = &self.thir[eid].kind + } + _ => return matches!(Category::of(&kind), Some(Category::Constant)), + } + } + } + fn build_zero_repeat( &mut self, mut block: BasicBlock, @@ -666,7 +685,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let this = self; let value_expr = &this.thir[value]; let elem_ty = value_expr.ty; - if let Some(Category::Constant) = Category::of(&value_expr.kind) { + if this.check_constness(&value_expr.kind) { // Repeating a const does nothing } else { // For a non-const, we may need to generate an appropriate `Drop` diff --git a/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs b/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs new file mode 100644 index 00000000000..eb814e9723c --- /dev/null +++ b/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs @@ -0,0 +1,30 @@ +//@ run-pass + +#![feature(unsize)] +#![feature(coerce_unsized)] + +use std::fmt::Display; +use std::marker::Unsize; +use std::ops::CoerceUnsized; + +#[repr(transparent)] +struct X<'a, T: ?Sized> { + f: &'a T, +} + +impl<'a, T: ?Sized> Drop for X<'a, T> { + fn drop(&mut self) { + panic!() + } +} + +impl<'a, T: ?Sized + Unsize, U: ?Sized> CoerceUnsized> for X<'a, T> where + &'a T: CoerceUnsized<&'a U> +{ +} + +const Y: X<'static, i32> = X { f: &0 }; + +fn main() { + let _: [X<'static, dyn Display>; 0] = [Y; 0]; +} -- cgit 1.4.1-3-g733a5 From 120162e30ffa92308a6a3a76f2328467fbd10ced Mon Sep 17 00:00:00 2001 From: Ding Xiang Fei Date: Wed, 13 Aug 2025 02:26:04 +0800 Subject: add test fixture for newly allowed const expr Signed-off-by: Ding Xiang Fei Co-authored-by: Theemathas Chirananthavat --- tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'tests/ui') diff --git a/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs b/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs index eb814e9723c..5924809f34c 100644 --- a/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs +++ b/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs @@ -6,6 +6,7 @@ use std::fmt::Display; use std::marker::Unsize; use std::ops::CoerceUnsized; +use std::rc::Weak; #[repr(transparent)] struct X<'a, T: ?Sized> { @@ -27,4 +28,11 @@ const Y: X<'static, i32> = X { f: &0 }; fn main() { let _: [X<'static, dyn Display>; 0] = [Y; 0]; + coercion_on_weak_in_const(); +} + +fn coercion_on_weak_in_const() { + const X: Weak = Weak::new(); + const Y: [Weak; 0] = [X; 0]; + let _ = Y; } -- cgit 1.4.1-3-g733a5 From b77de834c031890c048f8164d4b5979d2511c00e Mon Sep 17 00:00:00 2001 From: Ding Xiang Fei Date: Thu, 25 Sep 2025 01:53:34 +0800 Subject: mark THIR use as candidate for constness check --- compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs | 5 ++++- tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs | 8 ++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) (limited to 'tests/ui') diff --git a/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs index d6dc12e5955..3a5839f2d40 100644 --- a/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs +++ b/compiler/rustc_mir_build/src/builder/expr/as_rvalue.rs @@ -661,8 +661,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { /// operations that can be const-folded today. fn check_constness(&self, mut kind: &'a ExprKind<'tcx>) -> bool { loop { + debug!(?kind, "check_constness"); match kind { - &ExprKind::PointerCoercion { + &ExprKind::ValueTypeAscription { source: eid, user_ty: _, user_ty_span: _ } + | &ExprKind::Use { source: eid } + | &ExprKind::PointerCoercion { cast: PointerCoercion::Unsize, source: eid, is_from_as_cast: _, diff --git a/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs b/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs index 5924809f34c..38479d9070b 100644 --- a/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs +++ b/tests/ui/coercion/no_local_for_coerced_const-issue-143671.rs @@ -29,6 +29,7 @@ const Y: X<'static, i32> = X { f: &0 }; fn main() { let _: [X<'static, dyn Display>; 0] = [Y; 0]; coercion_on_weak_in_const(); + coercion_on_weak_as_cast(); } fn coercion_on_weak_in_const() { @@ -36,3 +37,10 @@ fn coercion_on_weak_in_const() { const Y: [Weak; 0] = [X; 0]; let _ = Y; } + +fn coercion_on_weak_as_cast() { + const Y: X<'static, i32> = X { f: &0 }; + // What happens in the following code is that + // a constant is explicitly coerced into + let _a: [X<'static, dyn Display>; 0] = [Y as X<'static, dyn Display>; 0]; +} -- cgit 1.4.1-3-g733a5