Couple of minor cleanups to the diagnostic infrastructure

compiler/rustc_driver_impl/src/lib.rs

@@ -1024,7 +1024,7 @@ pub fn describe_flag_categories(early_dcx: &EarlyDiagCtxt, matches: &Matches) ->
     let wall = matches.opt_strs("W");
     if wall.iter().any(|x| *x == "all") {
         print_wall_help();
-        rustc_errors::FatalError.raise();
+        return true;
     }
 
     // Don't handle -W help here, because we might first load additional lints.

compiler/rustc_errors/src/lib.rs

@@ -1048,8 +1048,8 @@ impl<'a> DiagCtxtHandle<'a> {
     /// bad results, such as spurious/uninteresting additional errors -- when
     /// returning an error `Result` is difficult.
     pub fn abort_if_errors(&self) {
-        if self.has_errors().is_some() {
-            FatalError.raise();
+        if let Some(guar) = self.has_errors() {
+            guar.raise_fatal();
         }
     }
 

compiler/rustc_interface/src/interface.rs

@@ -442,7 +442,6 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
             locale_resources.push(codegen_backend.locale_resource());
 
             let mut sess = rustc_session::build_session(
-                early_dcx,
                 config.opts,
                 CompilerIO {
                     input: config.input,

compiler/rustc_interface/src/tests.rs

@@ -65,7 +65,6 @@ where
         static USING_INTERNAL_FEATURES: AtomicBool = AtomicBool::new(false);
 
         let sess = build_session(
-            early_dcx,
             sessopts,
             io,
             None,

compiler/rustc_parse/src/parser/tests.rs

@@ -26,7 +26,7 @@ use crate::parser::{ForceCollect, Parser};
 use crate::{new_parser_from_source_str, source_str_to_stream, unwrap_or_emit_fatal};
 
 fn psess() -> ParseSess {
-    ParseSess::new(vec![crate::DEFAULT_LOCALE_RESOURCE, crate::DEFAULT_LOCALE_RESOURCE])
+    ParseSess::new(vec![crate::DEFAULT_LOCALE_RESOURCE])
 }
 
 /// Map string to parser (via tts).
@@ -41,10 +41,8 @@ fn string_to_parser(psess: &ParseSess, source_str: String) -> Parser<'_> {
 fn create_test_handler(theme: OutputTheme) -> (DiagCtxt, Arc<SourceMap>, Arc<Mutex<Vec<u8>>>) {
     let output = Arc::new(Mutex::new(Vec::new()));
     let source_map = Arc::new(SourceMap::new(FilePathMapping::empty()));
-    let fallback_bundle = rustc_errors::fallback_fluent_bundle(
-        vec![crate::DEFAULT_LOCALE_RESOURCE, crate::DEFAULT_LOCALE_RESOURCE],
-        false,
-    );
+    let fallback_bundle =
+        rustc_errors::fallback_fluent_bundle(vec![crate::DEFAULT_LOCALE_RESOURCE], false);
     let mut emitter = HumanEmitter::new(Box::new(Shared { data: output.clone() }), fallback_bundle)
         .sm(Some(source_map.clone()))
         .diagnostic_width(Some(140));

compiler/rustc_session/src/session.rs

@@ -965,7 +965,6 @@ fn default_emitter(
 #[allow(rustc::bad_opt_access)]
 #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn build_session(
-    early_dcx: EarlyDiagCtxt,
     sopts: config::Options,
     io: CompilerIO,
     bundle: Option<Arc<rustc_errors::FluentBundle>>,
@@ -990,14 +989,6 @@ pub fn build_session(
     let cap_lints_allow = sopts.lint_cap.is_some_and(|cap| cap == lint::Allow);
     let can_emit_warnings = !(warnings_allow || cap_lints_allow);
 
-    let host_triple = TargetTuple::from_tuple(config::host_tuple());
-    let (host, target_warnings) = Target::search(&host_triple, &sysroot).unwrap_or_else(|e| {
-        early_dcx.early_fatal(format!("Error loading host specification: {e}"))
-    });
-    for warning in target_warnings.warning_messages() {
-        early_dcx.early_warn(warning)
-    }
-
     let fallback_bundle = fallback_fluent_bundle(
         fluent_resources,
         sopts.unstable_opts.translate_directionality_markers,
@@ -1012,9 +1003,12 @@ pub fn build_session(
         dcx = dcx.with_ice_file(ice_file);
     }
 
-    // Now that the proper handler has been constructed, drop early_dcx to
-    // prevent accidental use.
-    drop(early_dcx);
+    let host_triple = TargetTuple::from_tuple(config::host_tuple());
+    let (host, target_warnings) = Target::search(&host_triple, &sysroot)
+        .unwrap_or_else(|e| dcx.handle().fatal(format!("Error loading host specification: {e}")));
+    for warning in target_warnings.warning_messages() {
+        dcx.handle().warn(warning)
+    }
 
     let self_profiler = if let SwitchWithOptPath::Enabled(ref d) = sopts.unstable_opts.self_profile
     {