cold

3 files changed, 35 insertions, 1 deletions

diff --git a/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
index ddcf82cbf7c..1509531ca98 100644
--- a/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
@@ -38,3 +38,21 @@ impl<S: Stage> SingleAttributeParser<S> for OptimizeParser {
         Some(AttributeKind::Optimize(res, cx.attr_span))
     }
 }
+
+pub(crate) struct ColdParser;
+
+impl<S: Stage> SingleAttributeParser<S> for ColdParser {
+    const PATH: &[rustc_span::Symbol] = &[sym::cold];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const TEMPLATE: AttributeTemplate = template!(Word);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        if !args.no_args() {
+            cx.expected_no_args(cx.attr_span);
+            return None;
+        };
+
+        Some(AttributeKind::Cold(cx.attr_span))
+    }
+}
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 1708fd72e58..e8bcf57e109 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -15,7 +15,7 @@ use rustc_session::Session;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 
 use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
-use crate::attributes::codegen_attrs::OptimizeParser;
+use crate::attributes::codegen_attrs::{ColdParser, OptimizeParser};
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::inline::{InlineParser, RustcForceInlineParser};
@@ -106,6 +106,7 @@ attribute_parsers!(
 
         // tidy-alphabetical-start
         Single<AsPtrParser>,
+        Single<ColdParser>,
         Single<ConstStabilityIndirectParser>,
         Single<DeprecationParser>,
         Single<InlineParser>,
@@ -234,6 +235,16 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
         })
     }
 
+    pub(crate) fn expected_no_args(&self, span: Span) -> ErrorGuaranteed {
+        self.emit_err(AttributeParseError {
+            span,
+            attr_span: self.attr_span,
+            template: self.template.clone(),
+            attribute: self.attr_path.clone(),
+            reason: AttributeParseErrorReason::ExpectedNoArgs,
+        })
+    }
+
     /// emit an error that a `name = value` pair was expected at this span. The symbol can be given for
     /// a nicer error message talking about the specific name that was found lacking a value.
     pub(crate) fn expected_name_value(&self, span: Span, name: Option<Symbol>) -> ErrorGuaranteed {
diff --git a/compiler/rustc_attr_parsing/src/session_diagnostics.rs b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
index 337921a318c..29f2e44a98a 100644
--- a/compiler/rustc_attr_parsing/src/session_diagnostics.rs
+++ b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
@@ -474,6 +474,7 @@ pub(crate) struct UnrecognizedReprHint {
 }
 
 pub(crate) enum AttributeParseErrorReason {
+    ExpectedNoArgs,
     ExpectedStringLiteral { byte_string: Option<Span> },
     ExpectedSingleArgument,
     ExpectedList,
@@ -529,6 +530,10 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError {
                 diag.span_label(self.span, format!("didn't expect a literal here"));
                 diag.code(E0565);
             }
+            AttributeParseErrorReason::ExpectedNoArgs => {
+                diag.span_label(self.span, format!("didn't expect any arguments here"));
+                diag.code(E0565);
+            }
             AttributeParseErrorReason::ExpectedNameValue(None) => {
                 diag.span_label(
                     self.span,