Use EmitterWithNote and allow warnings, adjust wording for --cfg/--check-cfg error

Author: mu001999

compiler/rustc_errors/src/emitter.rs

@@ -534,28 +534,24 @@ impl Emitter for HumanEmitter {
     }
 }
 
-/// An emitter that does nothing when emitting a non-error diagnostic.
-/// Error diagnostics are forwarded to `error_emitter` to avoid silent
-/// failures of rustc, as witnessed e.g. in issue #89358.
-pub struct ErrorOnlyEmitter {
-    pub error_emitter: Box<dyn Emitter + DynSend>,
-    pub error_note: String,
+/// An emitter that adds a note to each diagnostic.
+pub struct EmitterWithNote {
+    pub emitter: Box<dyn Emitter + DynSend>,
+    pub note: String,
 }
 
-impl Emitter for ErrorOnlyEmitter {
+impl Emitter for EmitterWithNote {
     fn source_map(&self) -> Option<&SourceMap> {
         None
     }
 
     fn emit_diagnostic(&mut self, mut diag: DiagInner, registry: &Registry) {
-        if diag.is_error() {
-            diag.sub(Level::Note, self.error_note.clone(), MultiSpan::new());
-            self.error_emitter.emit_diagnostic(diag, registry);
-        }
+        diag.sub(Level::Note, self.note.clone(), MultiSpan::new());
+        self.emitter.emit_diagnostic(diag, registry);
     }
 
     fn translator(&self) -> &Translator {
-        self.error_emitter.translator()
+        self.emitter.translator()
     }
 }
 

compiler/rustc_interface/src/interface.rs

@@ -53,20 +53,17 @@ pub struct Compiler {
 pub(crate) fn parse_cfg(dcx: DiagCtxtHandle<'_>, cfgs: Vec<String>) -> Cfg {
     cfgs.into_iter()
         .map(|s| {
-            let psess = ParseSess::with_error_emitter(
+            let psess = ParseSess::emitter_with_note(
                 vec![crate::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE],
-                format!("this error occurred on the command line: `--cfg={s}`"),
+                format!("this occurred on the command line: `--cfg={s}`"),
             );
             let filename = FileName::cfg_spec_source_code(&s);
 
             macro_rules! error {
                 ($reason: expr) => {
                     #[allow(rustc::untranslatable_diagnostic)]
                     #[allow(rustc::diagnostic_outside_of_impl)]
-                    dcx.fatal(format!(
-                        "invalid `--cfg` argument: `{}` ({})",
-                        s, $reason,
-                    ));
+                    dcx.fatal(format!("invalid `--cfg` argument: `{}` ({})", s, $reason,));
                 };
             }
 
@@ -88,7 +85,7 @@ pub(crate) fn parse_cfg(dcx: DiagCtxtHandle<'_>, cfgs: Vec<String>) -> Cfg {
                                     let ident = meta_item.ident().expect("multi-segment cfg key");
 
                                     if !ident.name.can_be_raw() {
-                                        error!(format!("argument key must be an identifier, but `{}` cannot be a raw identifier", ident.name));
+                                        error!("argument key must be an identifier");
                                     }
 
                                     return (ident.name, meta_item.value_str());
@@ -98,9 +95,9 @@ pub(crate) fn parse_cfg(dcx: DiagCtxtHandle<'_>, cfgs: Vec<String>) -> Cfg {
                         Ok(..) => {}
                         Err(err) => {
                             err.cancel();
-                        },
+                        }
                     }
-                },
+                }
                 Err(errs) => errs.into_iter().for_each(|err| {
                     err.cancel();
                 }),
@@ -129,9 +126,9 @@ pub(crate) fn parse_check_cfg(dcx: DiagCtxtHandle<'_>, specs: Vec<String>) -> Ch
     let mut check_cfg = CheckCfg { exhaustive_names, exhaustive_values, ..CheckCfg::default() };
 
     for s in specs {
-        let psess = ParseSess::with_error_emitter(
+        let psess = ParseSess::emitter_with_note(
             vec![crate::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE],
-            format!("this error occurred on the command line: `--check-cfg={s}`"),
+            format!("this occurred on the command line: `--check-cfg={s}`"),
         );
         let filename = FileName::cfg_spec_source_code(&s);
 
@@ -226,10 +223,7 @@ pub(crate) fn parse_check_cfg(dcx: DiagCtxtHandle<'_>, specs: Vec<String>) -> Ch
                 }
 
                 if !ident.name.can_be_raw() {
-                    error!(format!(
-                        "argument key must be an identifier, but `{}` cannot be a raw identifier",
-                        ident.name
-                    ));
+                    error!("`cfg()` names must be identifiers");
                 }
 
                 names.push(ident);

compiler/rustc_session/src/parse.rs

@@ -8,7 +8,7 @@ use rustc_ast::attr::AttrIdGenerator;
 use rustc_ast::node_id::NodeId;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap, FxIndexSet};
 use rustc_data_structures::sync::{AppendOnlyVec, Lock};
-use rustc_errors::emitter::{ErrorOnlyEmitter, HumanEmitter, stderr_destination};
+use rustc_errors::emitter::{EmitterWithNote, HumanEmitter, stderr_destination};
 use rustc_errors::translation::Translator;
 use rustc_errors::{
     BufferedEarlyLint, ColorConfig, DecorateDiagCompat, Diag, DiagCtxt, DiagCtxtHandle,
@@ -315,13 +315,12 @@ impl ParseSess {
         }
     }
 
-    pub fn with_error_emitter(locale_resources: Vec<&'static str>, error_note: String) -> Self {
+    pub fn emitter_with_note(locale_resources: Vec<&'static str>, note: String) -> Self {
         let translator = Translator::with_fallback_bundle(locale_resources, false);
         let sm = Arc::new(SourceMap::new(FilePathMapping::empty()));
         let emitter =
             Box::new(HumanEmitter::new(stderr_destination(ColorConfig::Auto), translator));
-        let dcx = DiagCtxt::new(Box::new(ErrorOnlyEmitter { error_emitter: emitter, error_note }))
-            .disable_warnings();
+        let dcx = DiagCtxt::new(Box::new(EmitterWithNote { emitter, note }));
         ParseSess::with_dcx(dcx, sm)
     }
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_crate.stderr

@@ -1,2 +1,2 @@
-error: invalid `--cfg` argument: `crate` (argument key must be an identifier, but `crate` cannot be a raw identifier)
+error: invalid `--cfg` argument: `crate` (argument key must be an identifier)
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_raw_crate.stderr

@@ -1,6 +1,6 @@
 error: `crate` cannot be a raw identifier
   |
-  = note: this error occurred on the command line: `--cfg=r#crate`
+  = note: this occurred on the command line: `--cfg=r#crate`
 
-error: invalid `--cfg` argument: `r#crate` (argument key must be an identifier, but `crate` cannot be a raw identifier)
+error: invalid `--cfg` argument: `r#crate` (argument key must be an identifier)
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_raw_self_lower.stderr

@@ -1,6 +1,6 @@
 error: `self` cannot be a raw identifier
   |
-  = note: this error occurred on the command line: `--cfg=r#self`
+  = note: this occurred on the command line: `--cfg=r#self`
 
-error: invalid `--cfg` argument: `r#self` (argument key must be an identifier, but `self` cannot be a raw identifier)
+error: invalid `--cfg` argument: `r#self` (argument key must be an identifier)
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_raw_self_upper.stderr

@@ -1,6 +1,6 @@
 error: `Self` cannot be a raw identifier
   |
-  = note: this error occurred on the command line: `--cfg=r#Self`
+  = note: this occurred on the command line: `--cfg=r#Self`
 
-error: invalid `--cfg` argument: `r#Self` (argument key must be an identifier, but `Self` cannot be a raw identifier)
+error: invalid `--cfg` argument: `r#Self` (argument key must be an identifier)
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_raw_super.stderr

@@ -1,6 +1,6 @@
 error: `super` cannot be a raw identifier
   |
-  = note: this error occurred on the command line: `--cfg=r#super`
+  = note: this occurred on the command line: `--cfg=r#super`
 
-error: invalid `--cfg` argument: `r#super` (argument key must be an identifier, but `super` cannot be a raw identifier)
+error: invalid `--cfg` argument: `r#super` (argument key must be an identifier)
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_raw_underscore.stderr

@@ -1,6 +1,6 @@
 error: `_` cannot be a raw identifier
   |
-  = note: this error occurred on the command line: `--cfg=r#_`
+  = note: this occurred on the command line: `--cfg=r#_`
 
-error: invalid `--cfg` argument: `r#_` (argument key must be an identifier, but `_` cannot be a raw identifier)
+error: invalid `--cfg` argument: `r#_` (argument key must be an identifier)
 

tests/ui/cfg/path-kw-as-cfg-pred-cli-cfg.cfg_self_lower.stderr

@@ -1,2 +1,2 @@
-error: invalid `--cfg` argument: `self` (argument key must be an identifier, but `self` cannot be a raw identifier)
+error: invalid `--cfg` argument: `self` (argument key must be an identifier)