Migrate derivable diagnostics in check_attr.rs

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

@@ -217,6 +217,8 @@ passes_debug_visualizer_invalid = invalid argument
     .note_2 = OR
     .note_3 = expected: `gdb_script_file = "..."`
 
+passes_debug_visualizer_unreadable = couldn't read {$file}: {$error}
+
 passes_rustc_allow_const_fn_unstable = attribute should be applied to `const fn`
     .label = not a `const fn`
 

compiler/rustc_passes/src/check_attr.rs

@@ -4,7 +4,7 @@
 //! conflicts between multiple such attributes attached to the same
 //! item.
 
-use crate::errors;
+use crate::errors::{self, DebugVisualizerUnreadable};
 use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{fluent, struct_span_err, Applicability, MultiSpan};
@@ -1842,13 +1842,11 @@ impl CheckAttrVisitor<'_> {
         match std::fs::File::open(&file) {
             Ok(_) => true,
             Err(err) => {
-                self.tcx
-                    .sess
-                    .struct_span_err(
-                        meta_item.span,
-                        &format!("couldn't read {}: {}", file.display(), err),
-                    )
-                    .emit();
+                self.tcx.sess.emit_err(DebugVisualizerUnreadable {
+                    span: meta_item.span,
+                    file: &file,
+                    error: err,
+                } );
                 false
             }
         }

compiler/rustc_passes/src/errors.rs

@@ -1,3 +1,5 @@
+use std::{io::Error, path::Path};
+
 use rustc_errors::{Applicability, MultiSpan};
 use rustc_hir::Target;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
@@ -527,6 +529,15 @@ pub struct DebugVisualizerInvalid {
     pub span: Span,
 }
 
+#[derive(SessionDiagnostic)]
+#[diag(passes::debug_visualizer_unreadable)]
+pub struct DebugVisualizerUnreadable<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub file: &'a Path,
+    pub error: Error,
+}
+
 #[derive(SessionDiagnostic)]
 #[diag(passes::rustc_allow_const_fn_unstable)]
 pub struct RustcAllowConstFnUnstable {