Migrated Unallowed function pointer calls in interpreter/ops

compiler/rustc_const_eval/src/errors.rs

@@ -95,3 +95,11 @@ pub(crate) struct MaxNumNodesExceeded {
     pub span: Span,
     pub s: String,
 }
+
+#[derive(SessionDiagnostic)]
+#[error(const_eval::unallowed_fn_pointer_call)]
+pub(crate) struct UnallowedFnPointerCall {
+    #[primary_span]
+    pub span: Span,
+    pub kind: ConstContext,
+}

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -25,7 +25,7 @@ use rustc_trait_selection::traits::SelectionContext;
 use super::ConstCx;
 use crate::errors::{
     MutDerefErr, NonConstOpErr, PanicNonStrErr, RawPtrToIntErr, StaticAccessErr,
-    TransientMutBorrowErr, TransientMutBorrowErrRaw,
+    TransientMutBorrowErr, TransientMutBorrowErrRaw, UnallowedFnPointerCall,
 };
 use crate::util::{call_kind, CallDesugaringKind, CallKind};
 
@@ -97,10 +97,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallIndirect {
         ccx: &ConstCx<'_, 'tcx>,
         span: Span,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
-        ccx.tcx.sess.struct_span_err(
-            span,
-            &format!("function pointer calls are not allowed in {}s", ccx.const_kind()),
-        )
+        ccx.tcx.sess.create_err(UnallowedFnPointerCall { span, kind: ccx.const_kind() })
     }
 }
 

compiler/rustc_error_messages/locales/en-US/const_eval.ftl

@@ -31,3 +31,5 @@ const_eval_transient_mut_borrow = mutable references are not allowed in {$kind}s
 const_eval_transient_mut_borrow_raw = raw mutable references are not allowed in {$kind}s
 
 const_evaL_max_num_nodes_exceeded = maximum number of nodes exceeded in constant {$s}
+
+const_eval_unallowed_fn_pointer_call = function pointer calls are not allowed in {$const_kind}s