Remove `is_lint` field from `Level::Error`.

Because it's redundant w.r.t. `Diagnostic::is_lint`, which is present
for every diagnostic level.

`struct_lint_level_impl` was the only place that set the `Error` field
to `true`, and it's also the only place that calls
`Diagnostic::is_lint()` to set the `is_lint` field.

compiler/rustc_builtin_macros/src/test.rs

@@ -395,7 +395,7 @@ fn not_testable_error(cx: &ExtCtxt<'_>, attr_sp: Span, item: Option<&ast::Item>)
         // These were a warning before #92959 and need to continue being that to avoid breaking
         // stable user code (#94508).
         Some(ast::ItemKind::MacCall(_)) => Level::Warning(None),
-        _ => Level::Error { lint: false },
+        _ => Level::Error,
     };
     let mut err = DiagnosticBuilder::<()>::new(dcx, level, msg);
     err.span(attr_sp);

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -416,7 +416,7 @@ fn report_inline_asm(
         cookie = 0;
     }
     let level = match level {
-        llvm::DiagnosticLevel::Error => Level::Error { lint: false },
+        llvm::DiagnosticLevel::Error => Level::Error,
         llvm::DiagnosticLevel::Warning => Level::Warning(None),
         llvm::DiagnosticLevel::Note | llvm::DiagnosticLevel::Remark => Level::Note,
     };

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -1848,7 +1848,7 @@ impl SharedEmitterMain {
                 }
                 Ok(SharedEmitterMessage::InlineAsmError(cookie, msg, level, source)) => {
                     let err_level = match level {
-                        Level::Error { lint: false } => Level::Error { lint: false },
+                        Level::Error => Level::Error,
                         Level::Warning(_) => Level::Warning(None),
                         Level::Note => Level::Note,
                         _ => bug!("Invalid inline asm diagnostic level"),

compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs

@@ -86,9 +86,7 @@ fn source_string(file: Lrc<SourceFile>, line: &Line) -> String {
 /// Maps `Diagnostic::Level` to `snippet::AnnotationType`
 fn annotation_type_for_level(level: Level) -> AnnotationType {
     match level {
-        Level::Bug | Level::DelayedBug | Level::Fatal | Level::Error { .. } => {
-            AnnotationType::Error
-        }
+        Level::Bug | Level::DelayedBug | Level::Fatal | Level::Error => AnnotationType::Error,
         Level::Warning(_) => AnnotationType::Warning,
         Level::Note | Level::OnceNote => AnnotationType::Note,
         Level::Help | Level::OnceHelp => AnnotationType::Help,

compiler/rustc_errors/src/diagnostic.rs

@@ -244,11 +244,9 @@ impl Diagnostic {
 
     pub fn is_error(&self) -> bool {
         match self.level {
-            Level::Bug
-            | Level::DelayedBug
-            | Level::Fatal
-            | Level::Error { .. }
-            | Level::FailureNote => true,
+            Level::Bug | Level::DelayedBug | Level::Fatal | Level::Error | Level::FailureNote => {
+                true
+            }
 
             Level::Warning(_)
             | Level::Note

compiler/rustc_errors/src/lib.rs

@@ -673,7 +673,7 @@ impl DiagCtxt {
         let key = (span.with_parent(None), key);
 
         if diag.is_error() {
-            if matches!(diag.level, Error { lint: true }) {
+            if diag.level == Error && diag.is_lint {
                 inner.lint_err_count += 1;
             } else {
                 inner.err_count += 1;
@@ -697,7 +697,7 @@ impl DiagCtxt {
         let key = (span.with_parent(None), key);
         let diag = inner.stashed_diagnostics.remove(&key)?;
         if diag.is_error() {
-            if matches!(diag.level, Error { lint: true }) {
+            if diag.level == Error && diag.is_lint {
                 inner.lint_err_count -= 1;
             } else {
                 inner.err_count -= 1;
@@ -812,7 +812,7 @@ impl DiagCtxt {
     #[rustc_lint_diagnostics]
     #[track_caller]
     pub fn struct_err(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_> {
-        DiagnosticBuilder::new(self, Error { lint: false }, msg)
+        DiagnosticBuilder::new(self, Error, msg)
     }
 
     /// Construct a builder at the `Error` level with the `msg` and the `code`.
@@ -1212,7 +1212,7 @@ impl DiagCtxt {
 
     #[track_caller]
     pub fn create_err<'a>(&'a self, err: impl IntoDiagnostic<'a>) -> DiagnosticBuilder<'a> {
-        err.into_diagnostic(self, Error { lint: false })
+        err.into_diagnostic(self, Error)
     }
 
     #[track_caller]
@@ -1367,7 +1367,7 @@ impl DiagCtxtInner {
         for diag in diags {
             // Decrement the count tracking the stash; emitting will increment it.
             if diag.is_error() {
-                if matches!(diag.level, Error { lint: true }) {
+                if diag.level == Error && diag.is_lint {
                     self.lint_err_count -= 1;
                 } else {
                     self.err_count -= 1;
@@ -1398,7 +1398,7 @@ impl DiagCtxtInner {
         &mut self,
         diagnostic: &mut Diagnostic,
     ) -> Option<ErrorGuaranteed> {
-        if matches!(diagnostic.level, Error { .. } | Fatal) && self.treat_err_as_bug() {
+        if matches!(diagnostic.level, Error | Fatal) && self.treat_err_as_bug() {
             diagnostic.level = Bug;
         }
 
@@ -1499,7 +1499,7 @@ impl DiagCtxtInner {
                 }
             }
             if diagnostic.is_error() {
-                if matches!(diagnostic.level, Error { lint: true }) {
+                if diagnostic.level == Error && diagnostic.is_lint {
                     self.bump_lint_err_count();
                 } else {
                     self.bump_err_count();
@@ -1695,11 +1695,7 @@ pub enum Level {
     /// most common case.
     ///
     /// Its `EmissionGuarantee` is `ErrorGuaranteed`.
-    Error {
-        /// If this error comes from a lint, don't abort compilation even when abort_if_errors() is
-        /// called.
-        lint: bool,
-    },
+    Error,
 
     /// A warning about the code being compiled. Does not prevent compilation from finishing.
     ///
@@ -1758,7 +1754,7 @@ impl Level {
     fn color(self) -> ColorSpec {
         let mut spec = ColorSpec::new();
         match self {
-            Bug | DelayedBug | Fatal | Error { .. } => {
+            Bug | DelayedBug | Fatal | Error => {
                 spec.set_fg(Some(Color::Red)).set_intense(true);
             }
             Warning(_) => {
@@ -1779,7 +1775,7 @@ impl Level {
     pub fn to_str(self) -> &'static str {
         match self {
             Bug | DelayedBug => "error: internal compiler error",
-            Fatal | Error { .. } => "error",
+            Fatal | Error => "error",
             Warning(_) => "warning",
             Note | OnceNote => "note",
             Help | OnceHelp => "help",

compiler/rustc_expand/src/proc_macro_server.rs

@@ -379,7 +379,7 @@ impl ToInternal<SmallVec<[tokenstream::TokenTree; 2]>>
 impl ToInternal<rustc_errors::Level> for Level {
     fn to_internal(self) -> rustc_errors::Level {
         match self {
-            Level::Error => rustc_errors::Level::Error { lint: false },
+            Level::Error => rustc_errors::Level::Error,
             Level::Warning => rustc_errors::Level::Warning(None),
             Level::Note => rustc_errors::Level::Note,
             Level::Help => rustc_errors::Level::Help,

compiler/rustc_middle/src/lint.rs

@@ -314,7 +314,7 @@ pub fn struct_lint_level(
             }
             Level::ForceWarn(Some(expect_id)) => rustc_errors::Level::Warning(Some(expect_id)),
             Level::Warn | Level::ForceWarn(None) => rustc_errors::Level::Warning(None),
-            Level::Deny | Level::Forbid => rustc_errors::Level::Error { lint: true },
+            Level::Deny | Level::Forbid => rustc_errors::Level::Error,
         };
         let mut err = DiagnosticBuilder::new(sess.dcx(), err_level, "");
         if let Some(span) = span {

src/tools/miri/src/diagnostics.rs

@@ -454,7 +454,7 @@ pub fn report_msg<'tcx>(
     let span = stacktrace.first().map_or(DUMMY_SP, |fi| fi.span);
     let sess = machine.tcx.sess;
     let level = match diag_level {
-        DiagLevel::Error => Level::Error { lint: false },
+        DiagLevel::Error => Level::Error,
         DiagLevel::Warning => Level::Warning(None),
         DiagLevel::Note => Level::Note,
     };