ADD - InvalidSymbolName to migrate symbol-name({}) error to new diagnostics infraestructure

ADD - dependencies needed to port a module to new Diagnostics infra (rustc_macros, rustc_errors, errors file, and fluent file)

Cargo.lock

@@ -4155,7 +4155,9 @@ dependencies = [
  "punycode",
  "rustc-demangle",
  "rustc_data_structures",
+ "rustc_errors",
  "rustc_hir",
+ "rustc_macros",
  "rustc_middle",
  "rustc_session",
  "rustc_span",

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

@@ -0,0 +1 @@
+symbol_mangling_invalid_symbol_name = symbol-name({$mangled_formatted})

compiler/rustc_error_messages/src/lib.rs

@@ -52,6 +52,7 @@
     ty_utils => "../locales/en-US/ty_utils.ftl",
     typeck => "../locales/en-US/typeck.ftl",
     mir_dataflow => "../locales/en-US/mir_dataflow.ftl",
+    symbol_mangling => "../locales/en-US/symbol_mangling.ftl",
 }
 
 pub use fluent_generated::{self as fluent, DEFAULT_LOCALE_RESOURCES};

compiler/rustc_symbol_mangling/Cargo.toml

@@ -18,3 +18,5 @@ rustc_hir = { path = "../rustc_hir" }
 rustc_target = { path = "../rustc_target" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_session = { path = "../rustc_session" }
+rustc_macros = { path = "../rustc_macros" }
+rustc_errors = { path = "../rustc_errors" }

compiler/rustc_symbol_mangling/src/errors.rs

@@ -0,0 +1,12 @@
+//! Errors emitted by symbol_mangling.
+
+use rustc_macros::SessionDiagnostic;
+use rustc_span::Span;
+
+#[derive(SessionDiagnostic)]
+#[error(symbol_mangling::invalid_symbol_name)]
+pub struct InvalidSymbolName<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub mangled_formatted: &'a str,
+}

compiler/rustc_symbol_mangling/src/lib.rs

@@ -110,6 +110,7 @@
 mod legacy;
 mod v0;
 
+pub mod errors;
 pub mod test;
 pub mod typeid;
 

compiler/rustc_symbol_mangling/src/test.rs

@@ -4,6 +4,7 @@
 //! def-path. This is used for unit testing the code that generates
 //! paths etc in all kinds of annoying scenarios.
 
+use crate::errors::InvalidSymbolName;
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{subst::InternalSubsts, Instance, TyCtxt};
@@ -59,7 +60,10 @@ fn process_attrs(&mut self, def_id: LocalDefId) {
                 tcx.erase_regions(InternalSubsts::identity_for_item(tcx, def_id)),
             );
             let mangled = tcx.symbol_name(instance);
-            tcx.sess.span_err(attr.span, &format!("symbol-name({})", mangled));
+            tcx.sess.emit_err(InvalidSymbolName {
+                span: attr.span,
+                mangled_formatted: &format!("{mangled}"),
+            });
             if let Ok(demangling) = rustc_demangle::try_demangle(mangled.name) {
                 tcx.sess.span_err(attr.span, &format!("demangling({})", demangling));
                 tcx.sess.span_err(attr.span, &format!("demangling-alt({:#})", demangling));