preserve span when evaluating mir::ConstOperand

21 files changed, 192 insertions, 7 deletions

diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
index c3e932fe187..f456196b282 100644
--- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
+++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
@@ -393,7 +393,9 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
                 }
             }
             Operand::Constant(box constant) => {
-                if let Ok(constant) = self.ecx.eval_mir_constant(&constant.const_, None, None) {
+                if let Ok(constant) =
+                    self.ecx.eval_mir_constant(&constant.const_, Some(constant.span), None)
+                {
                     self.assign_constant(state, place, constant, &[]);
                 }
             }
diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs
index ad8f21ffbda..6629face940 100644
--- a/compiler/rustc_mir_transform/src/jump_threading.rs
+++ b/compiler/rustc_mir_transform/src/jump_threading.rs
@@ -416,7 +416,8 @@ impl<'tcx, 'a> TOFinder<'tcx, 'a> {
         match rhs {
             // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`.
             Operand::Constant(constant) => {
-                let constant = self.ecx.eval_mir_constant(&constant.const_, None, None).ok()?;
+                let constant =
+                    self.ecx.eval_mir_constant(&constant.const_, Some(constant.span), None).ok()?;
                 self.process_constant(bb, lhs, constant, state);
             }
             // Transfer the conditions on the copied rhs.
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 2465f9fbfa8..cd9eb4916ce 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -828,14 +828,17 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> {
         // a codegen-time error). rustc stops after collection if there was an error, so this
         // ensures codegen never has to worry about failing consts.
         // (codegen relies on this and ICEs will happen if this is violated.)
-        let val = match const_.eval(self.tcx, param_env, None) {
+        let val = match const_.eval(self.tcx, param_env, Some(constant.span)) {
             Ok(v) => v,
-            Err(ErrorHandled::Reported(..)) => return,
             Err(ErrorHandled::TooGeneric(..)) => span_bug!(
                 self.body.source_info(location).span,
                 "collection encountered polymorphic constant: {:?}",
                 const_
             ),
+            Err(err @ ErrorHandled::Reported(..)) => {
+                err.emit_note(self.tcx);
+                return;
+            }
         };
         collect_const_value(self.tcx, val, self.output);
         MirVisitor::visit_ty(self, const_.ty(), TyContext::Location(location));
diff --git a/compiler/rustc_smir/src/rustc_smir/builder.rs b/compiler/rustc_smir/src/rustc_smir/builder.rs
index 039bdec4c78..a13262cdcc4 100644
--- a/compiler/rustc_smir/src/rustc_smir/builder.rs
+++ b/compiler/rustc_smir/src/rustc_smir/builder.rs
@@ -56,7 +56,7 @@ impl<'tcx> MutVisitor<'tcx> for BodyBuilder<'tcx> {
 
     fn visit_constant(&mut self, constant: &mut mir::ConstOperand<'tcx>, location: mir::Location) {
         let const_ = self.monomorphize(constant.const_);
-        let val = match const_.eval(self.tcx, ty::ParamEnv::reveal_all(), None) {
+        let val = match const_.eval(self.tcx, ty::ParamEnv::reveal_all(), Some(constant.span)) {
             Ok(v) => v,
             Err(mir::interpret::ErrorHandled::Reported(..)) => return,
             Err(mir::interpret::ErrorHandled::TooGeneric(..)) => {
diff --git a/tests/ui/consts/assoc_const_generic_impl.stderr b/tests/ui/consts/assoc_const_generic_impl.stderr
index d826972ce9f..45219508396 100644
--- a/tests/ui/consts/assoc_const_generic_impl.stderr
+++ b/tests/ui/consts/assoc_const_generic_impl.stderr
@@ -4,6 +4,12 @@ error[E0080]: evaluation of `<u32 as ZeroSized>::I_AM_ZERO_SIZED` failed
 LL |     const I_AM_ZERO_SIZED: ()  = [()][std::mem::size_of::<Self>()];
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ index out of bounds: the length is 1 but the index is 4
 
+note: erroneous constant encountered
+  --> $DIR/assoc_const_generic_impl.rs:11:9
+   |
+LL |         Self::I_AM_ZERO_SIZED;
+   |         ^^^^^^^^^^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn <u32 as ZeroSized>::requires_zero_size`
   --> $DIR/assoc_const_generic_impl.rs:18:5
    |
diff --git a/tests/ui/consts/const-eval/index-out-of-bounds-never-type.stderr b/tests/ui/consts/const-eval/index-out-of-bounds-never-type.stderr
index 4e7ef52f674..7facb2d1a5c 100644
--- a/tests/ui/consts/const-eval/index-out-of-bounds-never-type.stderr
+++ b/tests/ui/consts/const-eval/index-out-of-bounds-never-type.stderr
@@ -4,6 +4,12 @@ error[E0080]: evaluation of `PrintName::<()>::VOID` failed
 LL |     const VOID: ! = { let x = 0 * std::mem::size_of::<T>(); [][x] };
    |                                                             ^^^^^ index out of bounds: the length is 0 but the index is 0
 
+note: erroneous constant encountered
+  --> $DIR/index-out-of-bounds-never-type.rs:16:13
+   |
+LL |     let _ = PrintName::<T>::VOID;
+   |             ^^^^^^^^^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn f::<()>`
   --> $DIR/index-out-of-bounds-never-type.rs:20:5
    |
diff --git a/tests/ui/consts/const-eval/issue-50814-2.mir-opt.stderr b/tests/ui/consts/const-eval/issue-50814-2.mir-opt.stderr
index 7e764ca7239..2de68d3fee9 100644
--- a/tests/ui/consts/const-eval/issue-50814-2.mir-opt.stderr
+++ b/tests/ui/consts/const-eval/issue-50814-2.mir-opt.stderr
@@ -10,6 +10,52 @@ note: erroneous constant encountered
 LL |     &<A<T> as Foo<T>>::BAR
    |      ^^^^^^^^^^^^^^^^^^^^^
 
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:5
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:5
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:5
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:5
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:6
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |      ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:6
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |      ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/issue-50814-2.normal.stderr b/tests/ui/consts/const-eval/issue-50814-2.normal.stderr
index f552c8fde5b..4a7dfb19304 100644
--- a/tests/ui/consts/const-eval/issue-50814-2.normal.stderr
+++ b/tests/ui/consts/const-eval/issue-50814-2.normal.stderr
@@ -10,6 +10,20 @@ note: erroneous constant encountered
 LL |     &<A<T> as Foo<T>>::BAR
    |      ^^^^^^^^^^^^^^^^^^^^^
 
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:5
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814-2.rs:20:6
+   |
+LL |     &<A<T> as Foo<T>>::BAR
+   |      ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: the above error was encountered while instantiating `fn foo::<()>`
   --> $DIR/issue-50814-2.rs:32:22
    |
diff --git a/tests/ui/consts/const-eval/issue-50814.stderr b/tests/ui/consts/const-eval/issue-50814.stderr
index 8d018161401..fe0e25b820f 100644
--- a/tests/ui/consts/const-eval/issue-50814.stderr
+++ b/tests/ui/consts/const-eval/issue-50814.stderr
@@ -26,6 +26,20 @@ LL |     &Sum::<U8, U8>::MAX
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
+note: erroneous constant encountered
+  --> $DIR/issue-50814.rs:21:5
+   |
+LL |     &Sum::<U8, U8>::MAX
+   |     ^^^^^^^^^^^^^^^^^^^
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814.rs:21:6
+   |
+LL |     &Sum::<U8, U8>::MAX
+   |      ^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: the above error was encountered while instantiating `fn foo::<i32>`
   --> $DIR/issue-50814.rs:26:5
    |
diff --git a/tests/ui/consts/const-eval/issue-85155.stderr b/tests/ui/consts/const-eval/issue-85155.stderr
index a88e959a8a6..99836a3fac6 100644
--- a/tests/ui/consts/const-eval/issue-85155.stderr
+++ b/tests/ui/consts/const-eval/issue-85155.stderr
@@ -4,6 +4,14 @@ error[E0080]: evaluation of `post_monomorphization_error::ValidateConstImm::<2,
 LL |         let _ = 1 / ((IMM >= MIN && IMM <= MAX) as usize);
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempt to divide `1_usize` by zero
 
+note: erroneous constant encountered
+  --> $DIR/auxiliary/post_monomorphization_error.rs:19:5
+   |
+LL |     static_assert_imm1!(IMM1);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this note originates in the macro `static_assert_imm1` (in Nightly builds, run with -Z macro-backtrace for more info)
+
 note: the above error was encountered while instantiating `fn post_monomorphization_error::stdarch_intrinsic::<2>`
   --> $DIR/issue-85155.rs:19:5
    |
diff --git a/tests/ui/consts/required-consts/collect-in-called-fn.noopt.stderr b/tests/ui/consts/required-consts/collect-in-called-fn.noopt.stderr
index c7ff1328917..14a4cb0217f 100644
--- a/tests/ui/consts/required-consts/collect-in-called-fn.noopt.stderr
+++ b/tests/ui/consts/required-consts/collect-in-called-fn.noopt.stderr
@@ -6,6 +6,12 @@ LL |     const C: () = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/collect-in-called-fn.rs:18:17
+   |
+LL |         let _ = Fail::<T>::C;
+   |                 ^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn called::<i32>`
   --> $DIR/collect-in-called-fn.rs:23:5
    |
diff --git a/tests/ui/consts/required-consts/collect-in-called-fn.opt.stderr b/tests/ui/consts/required-consts/collect-in-called-fn.opt.stderr
index c7ff1328917..14a4cb0217f 100644
--- a/tests/ui/consts/required-consts/collect-in-called-fn.opt.stderr
+++ b/tests/ui/consts/required-consts/collect-in-called-fn.opt.stderr
@@ -6,6 +6,12 @@ LL |     const C: () = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/collect-in-called-fn.rs:18:17
+   |
+LL |         let _ = Fail::<T>::C;
+   |                 ^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn called::<i32>`
   --> $DIR/collect-in-called-fn.rs:23:5
    |
diff --git a/tests/ui/consts/required-consts/collect-in-dead-drop.noopt.stderr b/tests/ui/consts/required-consts/collect-in-dead-drop.noopt.stderr
index b7010e78763..0bf231d09f1 100644
--- a/tests/ui/consts/required-consts/collect-in-dead-drop.noopt.stderr
+++ b/tests/ui/consts/required-consts/collect-in-dead-drop.noopt.stderr
@@ -6,6 +6,12 @@ LL |     const C: () = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/collect-in-dead-drop.rs:19:17
+   |
+LL |         let _ = Fail::<T>::C;
+   |                 ^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn <Fail<i32> as std::ops::Drop>::drop`
   --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
 
diff --git a/tests/ui/consts/required-consts/collect-in-dead-fn.noopt.stderr b/tests/ui/consts/required-consts/collect-in-dead-fn.noopt.stderr
index 2162c35c837..8bb99efe8e4 100644
--- a/tests/ui/consts/required-consts/collect-in-dead-fn.noopt.stderr
+++ b/tests/ui/consts/required-consts/collect-in-dead-fn.noopt.stderr
@@ -6,6 +6,12 @@ LL |     const C: () = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/collect-in-dead-fn.rs:22:17
+   |
+LL |         let _ = Fail::<T>::C;
+   |                 ^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn not_called::<i32>`
   --> $DIR/collect-in-dead-fn.rs:29:9
    |
diff --git a/tests/ui/consts/required-consts/collect-in-dead-move.noopt.stderr b/tests/ui/consts/required-consts/collect-in-dead-move.noopt.stderr
index 8c853127e04..5b1df78b232 100644
--- a/tests/ui/consts/required-consts/collect-in-dead-move.noopt.stderr
+++ b/tests/ui/consts/required-consts/collect-in-dead-move.noopt.stderr
@@ -6,6 +6,12 @@ LL |     const C: () = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/collect-in-dead-move.rs:19:17
+   |
+LL |         let _ = Fail::<T>::C;
+   |                 ^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn <Fail<i32> as std::ops::Drop>::drop`
   --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
 
diff --git a/tests/ui/consts/required-consts/collect-in-dead-vtable.noopt.stderr b/tests/ui/consts/required-consts/collect-in-dead-vtable.noopt.stderr
index 6fd82777bd3..56b6989b441 100644
--- a/tests/ui/consts/required-consts/collect-in-dead-vtable.noopt.stderr
+++ b/tests/ui/consts/required-consts/collect-in-dead-vtable.noopt.stderr
@@ -6,6 +6,12 @@ LL |     const C: () = panic!();
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/collect-in-dead-vtable.rs:26:21
+   |
+LL |             let _ = Fail::<T>::C;
+   |                     ^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn <std::vec::Vec<i32> as MyTrait>::not_called`
   --> $DIR/collect-in-dead-vtable.rs:35:40
    |
diff --git a/tests/ui/generics/post_monomorphization_error_backtrace.rs b/tests/ui/generics/post_monomorphization_error_backtrace.rs
index 56155ae2bd5..2c18f2b233a 100644
--- a/tests/ui/generics/post_monomorphization_error_backtrace.rs
+++ b/tests/ui/generics/post_monomorphization_error_backtrace.rs
@@ -12,6 +12,9 @@ fn assert_zst<T>() {
         //~| NOTE: the evaluated program panicked
     }
     F::<T>::V;
+    //~^NOTE: erroneous constant
+    //~|NOTE: erroneous constant
+    //~|NOTE: duplicate
 }
 
 fn foo<U>() {
diff --git a/tests/ui/generics/post_monomorphization_error_backtrace.stderr b/tests/ui/generics/post_monomorphization_error_backtrace.stderr
index 0d707d83d26..8a57979bca7 100644
--- a/tests/ui/generics/post_monomorphization_error_backtrace.stderr
+++ b/tests/ui/generics/post_monomorphization_error_backtrace.stderr
@@ -6,8 +6,14 @@ LL |         const V: () = assert!(std::mem::size_of::<T>() == 0);
    |
    = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/post_monomorphization_error_backtrace.rs:14:5
+   |
+LL |     F::<T>::V;
+   |     ^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn assert_zst::<u32>`
-  --> $DIR/post_monomorphization_error_backtrace.rs:18:5
+  --> $DIR/post_monomorphization_error_backtrace.rs:21:5
    |
 LL |     assert_zst::<U>()
    |     ^^^^^^^^^^^^^^^^^
@@ -20,8 +26,16 @@ LL |         const V: () = assert!(std::mem::size_of::<T>() == 0);
    |
    = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/post_monomorphization_error_backtrace.rs:14:5
+   |
+LL |     F::<T>::V;
+   |     ^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: the above error was encountered while instantiating `fn assert_zst::<i32>`
-  --> $DIR/post_monomorphization_error_backtrace.rs:18:5
+  --> $DIR/post_monomorphization_error_backtrace.rs:21:5
    |
 LL |     assert_zst::<U>()
    |     ^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/inline-const/const-expr-generic-err.stderr b/tests/ui/inline-const/const-expr-generic-err.stderr
index fc0b6cc4451..7331c7f18e9 100644
--- a/tests/ui/inline-const/const-expr-generic-err.stderr
+++ b/tests/ui/inline-const/const-expr-generic-err.stderr
@@ -6,6 +6,12 @@ LL |     const { assert!(std::mem::size_of::<T>() == 0); }
    |
    = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/const-expr-generic-err.rs:5:5
+   |
+LL |     const { assert!(std::mem::size_of::<T>() == 0); }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn foo::<i32>`
   --> $DIR/const-expr-generic-err.rs:13:5
    |
@@ -18,6 +24,20 @@ error[E0080]: evaluation of `bar::<0>::{constant#0}` failed
 LL |     const { N - 1 }
    |             ^^^^^ attempt to compute `0_usize - 1_usize`, which would overflow
 
+note: erroneous constant encountered
+  --> $DIR/const-expr-generic-err.rs:9:5
+   |
+LL |     const { N - 1 }
+   |     ^^^^^^^^^^^^^^^
+
+note: erroneous constant encountered
+  --> $DIR/const-expr-generic-err.rs:9:5
+   |
+LL |     const { N - 1 }
+   |     ^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: the above error was encountered while instantiating `fn bar::<0>`
   --> $DIR/const-expr-generic-err.rs:14:5
    |
diff --git a/tests/ui/inline-const/required-const.stderr b/tests/ui/inline-const/required-const.stderr
index cd86020184d..2a13d18547c 100644
--- a/tests/ui/inline-const/required-const.stderr
+++ b/tests/ui/inline-const/required-const.stderr
@@ -6,6 +6,12 @@ LL |         const { panic!() }
    |
    = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/required-const.rs:7:9
+   |
+LL |         const { panic!() }
+   |         ^^^^^^^^^^^^^^^^^^
+
 error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/simd/const-err-trumps-simd-err.stderr b/tests/ui/simd/const-err-trumps-simd-err.stderr
index 6e6aba8b6f1..1e46667cf4e 100644
--- a/tests/ui/simd/const-err-trumps-simd-err.stderr
+++ b/tests/ui/simd/const-err-trumps-simd-err.stderr
@@ -6,6 +6,12 @@ LL |     const { assert!(LANE < 4); } // the error should be here...
    |
    = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+note: erroneous constant encountered
+  --> $DIR/const-err-trumps-simd-err.rs:16:5
+   |
+LL |     const { assert!(LANE < 4); } // the error should be here...
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 note: the above error was encountered while instantiating `fn get_elem::<4>`
   --> $DIR/const-err-trumps-simd-err.rs:23:5
    |