SilentEmitter::fatal_note doesn't need to be optional.

Author: nnethercote

compiler/rustc_errors/src/emitter.rs

@@ -558,7 +558,7 @@ impl Emitter for HumanEmitter {
 /// failures of rustc, as witnessed e.g. in issue #89358.
 pub struct SilentEmitter {
     pub fatal_dcx: DiagCtxt,
-    pub fatal_note: Option<String>,
+    pub fatal_note: String,
 }
 
 impl Translate for SilentEmitter {
@@ -576,13 +576,11 @@ impl Emitter for SilentEmitter {
         None
     }
 
-    fn emit_diagnostic(&mut self, d: &Diagnostic) {
-        if d.level == Level::Fatal {
-            let mut d = d.clone();
-            if let Some(ref note) = self.fatal_note {
-                d.note(note.clone());
-            }
-            self.fatal_dcx.emit_diagnostic(d);
+    fn emit_diagnostic(&mut self, diag: &Diagnostic) {
+        if diag.level == Level::Fatal {
+            let mut diag = diag.clone();
+            diag.note(self.fatal_note.clone());
+            self.fatal_dcx.emit_diagnostic(diag);
         }
     }
 }

compiler/rustc_interface/src/interface.rs

@@ -45,9 +45,9 @@ pub struct Compiler {
 pub(crate) fn parse_cfg(dcx: &DiagCtxt, cfgs: Vec<String>) -> Cfg {
     cfgs.into_iter()
         .map(|s| {
-            let sess = ParseSess::with_silent_emitter(Some(format!(
+            let sess = ParseSess::with_silent_emitter(format!(
                 "this error occurred on the command line: `--cfg={s}`"
-            )));
+            ));
             let filename = FileName::cfg_spec_source_code(&s);
 
             macro_rules! error {
@@ -107,9 +107,9 @@ pub(crate) fn parse_check_cfg(dcx: &DiagCtxt, specs: Vec<String>) -> CheckCfg {
     let mut check_cfg = CheckCfg { exhaustive_names, exhaustive_values, ..CheckCfg::default() };
 
     for s in specs {
-        let sess = ParseSess::with_silent_emitter(Some(format!(
+        let sess = ParseSess::with_silent_emitter(format!(
             "this error occurred on the command line: `--check-cfg={s}`"
-        )));
+        ));
         let filename = FileName::cfg_spec_source_code(&s);
 
         macro_rules! error {

compiler/rustc_session/src/parse.rs

@@ -258,7 +258,7 @@ impl ParseSess {
         }
     }
 
-    pub fn with_silent_emitter(fatal_note: Option<String>) -> Self {
+    pub fn with_silent_emitter(fatal_note: String) -> Self {
         let fallback_bundle = fallback_fluent_bundle(Vec::new(), false);
         let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
         let fatal_dcx = DiagCtxt::with_tty_emitter(None, fallback_bundle).disable_warnings();