Rollup merge of #121382 - nnethercote:rework-untranslatable_diagnostic-lint, r=davidtwco

Rework `untranslatable_diagnostic` lint

Currently it only checks calls to functions marked with `#[rustc_lint_diagnostics]`. This PR changes it to check calls to any function with an `impl Into<{D,Subd}iagnosticMessage>` parameter. This greatly improves its coverage and doesn't rely on people remembering to add `#[rustc_lint_diagnostics]`. It also lets us add `#[rustc_lint_diagnostics]` to a number of functions that don't have an `impl Into<{D,Subd}iagnosticMessage>`, such as `Diag::span`.

r? ``@davidtwco``

compiler/rustc_session/src/config.rs

@@ -1,6 +1,8 @@
 //! Contains infrastructure for configuring the compiler, including parsing
 //! command-line options.
 
+#![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
+
 pub use crate::options::*;
 
 use crate::errors::FileWriteFail;
@@ -2468,9 +2470,7 @@ pub fn parse_externs(
             ));
             let adjusted_name = name.replace('-', "_");
             if is_ascii_ident(&adjusted_name) {
-                // FIXME: make this translatable
-                #[allow(rustc::diagnostic_outside_of_impl)]
-                #[allow(rustc::untranslatable_diagnostic)]
+                #[allow(rustc::diagnostic_outside_of_impl)] // FIXME
                 error.help(format!(
                     "consider replacing the dashes with underscores: `{adjusted_name}`"
                 ));

compiler/rustc_session/src/options.rs

@@ -320,6 +320,7 @@ macro_rules! redirect_field {
 type OptionSetter<O> = fn(&mut O, v: Option<&str>) -> bool;
 type OptionDescrs<O> = &'static [(&'static str, OptionSetter<O>, &'static str, &'static str)];
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn build_options<O: Default>(
     early_dcx: &EarlyDiagCtxt,
     matches: &getopts::Matches,

compiler/rustc_session/src/parse.rs

@@ -168,6 +168,7 @@ pub fn add_feature_diagnostics<G: EmissionGuarantee>(
 /// This variant allows you to control whether it is a library or language feature.
 /// Almost always, you want to use this for a language feature. If so, prefer
 /// `add_feature_diagnostics`.
+#[allow(rustc::diagnostic_outside_of_impl)] // FIXME
 pub fn add_feature_diagnostics_for_issue<G: EmissionGuarantee>(
     err: &mut Diag<'_, G>,
     sess: &Session,

compiler/rustc_session/src/search_paths.rs

@@ -61,6 +61,7 @@ impl SearchPath {
             (PathKind::All, path)
         };
         if path.is_empty() {
+            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
             early_dcx.early_fatal("empty search path given via `-L`");
         }
 

compiler/rustc_session/src/session.rs

@@ -312,6 +312,7 @@ impl Session {
     ) -> Diag<'a> {
         let mut err = self.dcx().create_err(err);
         if err.code.is_none() {
+            #[allow(rustc::diagnostic_outside_of_impl)]
             err.code(E0658);
         }
         add_feature_diagnostics(&mut err, self, feature);
@@ -1022,6 +1023,7 @@ fn default_emitter(
 
 // JUSTIFICATION: literally session construction
 #[allow(rustc::bad_opt_access)]
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn build_session(
     early_dcx: EarlyDiagCtxt,
     sopts: config::Options,