Rollup merge of #98657 - compiler-errors:rustc-const-eval-session-diagnostic-1, r=davidtwco

Migrate some diagnostics from `rustc_const_eval` to `SessionDiagnostic`

I'm still trying to get the hang of this, so it doesn't migrate _all_ of `rustc_const_eval`. Working on that later.

r? `@davidtwco`

1 files changed, 11 insertions, 0 deletions

diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 0d1d017d874..9429ad1a897 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -5,6 +5,7 @@ use crate::{
 };
 use rustc_data_structures::stable_map::FxHashMap;
 use rustc_error_messages::FluentValue;
+use rustc_hir as hir;
 use rustc_lint_defs::{Applicability, LintExpectationId};
 use rustc_span::edition::LATEST_STABLE_EDITION;
 use rustc_span::symbol::{Ident, Symbol};
@@ -160,6 +161,16 @@ impl<'source> Into<FluentValue<'source>> for DiagnosticArgValue<'source> {
     }
 }
 
+impl IntoDiagnosticArg for hir::ConstContext {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::Borrowed(match self {
+            hir::ConstContext::ConstFn => "constant function",
+            hir::ConstContext::Static(_) => "static",
+            hir::ConstContext::Const => "constant",
+        }))
+    }
+}
+
 /// Trait implemented by error types. This should not be implemented manually. Instead, use
 /// `#[derive(SessionSubdiagnostic)]` -- see [rustc_macros::SessionSubdiagnostic].
 #[rustc_diagnostic_item = "AddSubdiagnostic"]