Merge pull request #2512 from rust-lang/rustc-pull

Rustc pull update

8 files changed, 211 insertions, 39 deletions

diff --git a/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs b/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
index 1c51c3eee4e..a6bd2306ec5 100644
--- a/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
@@ -27,6 +27,26 @@ impl<S: Stage> CombineAttributeParser<S> for AllowInternalUnstableParser {
     }
 }
 
+pub(crate) struct UnstableFeatureBoundParser;
+impl<S: Stage> CombineAttributeParser<S> for UnstableFeatureBoundParser {
+    const PATH: &'static [rustc_span::Symbol] = &[sym::unstable_feature_bound];
+    type Item = (Symbol, Span);
+    const CONVERT: ConvertFn<Self::Item> = |items, _| AttributeKind::UnstableFeatureBound(items);
+    const TEMPLATE: AttributeTemplate = template!(Word, List: "feat1, feat2, ...");
+
+    fn extend<'c>(
+        cx: &'c mut AcceptContext<'_, '_, S>,
+        args: &'c ArgParser<'_>,
+    ) -> impl IntoIterator<Item = Self::Item> {
+        if !cx.features().staged_api() {
+            cx.emit_err(session_diagnostics::StabilityOutsideStd { span: cx.attr_span });
+        }
+        parse_unstable(cx, args, <Self as CombineAttributeParser<S>>::PATH[0])
+            .into_iter()
+            .zip(iter::repeat(cx.attr_span))
+    }
+}
+
 pub(crate) struct AllowConstFnUnstableParser;
 impl<S: Stage> CombineAttributeParser<S> for AllowConstFnUnstableParser {
     const PATH: &[Symbol] = &[sym::rustc_allow_const_fn_unstable];
diff --git a/compiler/rustc_attr_parsing/src/attributes/cfg.rs b/compiler/rustc_attr_parsing/src/attributes/cfg.rs
index a56855b3bd3..6373cf6e08a 100644
--- a/compiler/rustc_attr_parsing/src/attributes/cfg.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/cfg.rs
@@ -9,7 +9,7 @@ use rustc_session::parse::feature_err;
 use rustc_span::{Span, Symbol, sym};
 use thin_vec::ThinVec;
 
-use crate::context::{AcceptContext, Stage};
+use crate::context::{AcceptContext, ShouldEmit, Stage};
 use crate::parser::{ArgParser, MetaItemListParser, MetaItemOrLitParser, NameValueParser};
 use crate::{
     CfgMatchesLintEmitter, fluent_generated, parse_version, session_diagnostics, try_gate_cfg,
@@ -90,7 +90,7 @@ fn parse_cfg_entry_version<S: Stage>(
     list: &MetaItemListParser<'_>,
     meta_span: Span,
 ) -> Option<CfgEntry> {
-    try_gate_cfg(sym::version, meta_span, cx.sess(), Some(cx.features()));
+    try_gate_cfg(sym::version, meta_span, cx.sess(), cx.features_option());
     let Some(version) = list.single() else {
         cx.emit_err(session_diagnostics::ExpectedSingleVersionLiteral { span: list.span });
         return None;
@@ -119,7 +119,9 @@ fn parse_cfg_entry_target<S: Stage>(
     list: &MetaItemListParser<'_>,
     meta_span: Span,
 ) -> Option<CfgEntry> {
-    if !cx.features().cfg_target_compact() {
+    if let Some(features) = cx.features_option()
+        && !features.cfg_target_compact()
+    {
         feature_err(
             cx.sess(),
             sym::cfg_target_compact,
@@ -186,12 +188,13 @@ pub fn eval_config_entry(
     cfg_entry: &CfgEntry,
     id: NodeId,
     features: Option<&Features>,
+    emit_lints: ShouldEmit,
 ) -> EvalConfigResult {
     match cfg_entry {
         CfgEntry::All(subs, ..) => {
             let mut all = None;
             for sub in subs {
-                let res = eval_config_entry(sess, sub, id, features);
+                let res = eval_config_entry(sess, sub, id, features, emit_lints);
                 // We cannot short-circuit because `eval_config_entry` emits some lints
                 if !res.as_bool() {
                     all.get_or_insert(res);
@@ -202,7 +205,7 @@ pub fn eval_config_entry(
         CfgEntry::Any(subs, span) => {
             let mut any = None;
             for sub in subs {
-                let res = eval_config_entry(sess, sub, id, features);
+                let res = eval_config_entry(sess, sub, id, features, emit_lints);
                 // We cannot short-circuit because `eval_config_entry` emits some lints
                 if res.as_bool() {
                     any.get_or_insert(res);
@@ -214,7 +217,7 @@ pub fn eval_config_entry(
             })
         }
         CfgEntry::Not(sub, span) => {
-            if eval_config_entry(sess, sub, id, features).as_bool() {
+            if eval_config_entry(sess, sub, id, features, emit_lints).as_bool() {
                 EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }
             } else {
                 EvalConfigResult::True
@@ -228,24 +231,28 @@ pub fn eval_config_entry(
             }
         }
         CfgEntry::NameValue { name, name_span, value, span } => {
-            match sess.psess.check_config.expecteds.get(name) {
-                Some(ExpectedValues::Some(values)) if !values.contains(&value.map(|(v, _)| v)) => {
-                    id.emit_span_lint(
-                        sess,
-                        UNEXPECTED_CFGS,
-                        *span,
-                        BuiltinLintDiag::UnexpectedCfgValue((*name, *name_span), *value),
-                    );
+            if let ShouldEmit::ErrorsAndLints = emit_lints {
+                match sess.psess.check_config.expecteds.get(name) {
+                    Some(ExpectedValues::Some(values))
+                        if !values.contains(&value.map(|(v, _)| v)) =>
+                    {
+                        id.emit_span_lint(
+                            sess,
+                            UNEXPECTED_CFGS,
+                            *span,
+                            BuiltinLintDiag::UnexpectedCfgValue((*name, *name_span), *value),
+                        );
+                    }
+                    None if sess.psess.check_config.exhaustive_names => {
+                        id.emit_span_lint(
+                            sess,
+                            UNEXPECTED_CFGS,
+                            *span,
+                            BuiltinLintDiag::UnexpectedCfgName((*name, *name_span), *value),
+                        );
+                    }
+                    _ => { /* not unexpected */ }
                 }
-                None if sess.psess.check_config.exhaustive_names => {
-                    id.emit_span_lint(
-                        sess,
-                        UNEXPECTED_CFGS,
-                        *span,
-                        BuiltinLintDiag::UnexpectedCfgName((*name, *name_span), *value),
-                    );
-                }
-                _ => { /* not unexpected */ }
             }
 
             if sess.psess.config.contains(&(*name, value.map(|(v, _)| v))) {
diff --git a/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
index 34d9b048348..3e542771d58 100644
--- a/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
@@ -1,4 +1,4 @@
-use rustc_attr_data_structures::{AttributeKind, OptimizeAttr, UsedBy};
+use rustc_attr_data_structures::{AttributeKind, CoverageStatus, OptimizeAttr, UsedBy};
 use rustc_feature::{AttributeTemplate, template};
 use rustc_session::parse::feature_err;
 use rustc_span::{Span, Symbol, sym};
@@ -52,6 +52,45 @@ impl<S: Stage> NoArgsAttributeParser<S> for ColdParser {
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::Cold;
 }
 
+pub(crate) struct CoverageParser;
+
+impl<S: Stage> SingleAttributeParser<S> for CoverageParser {
+    const PATH: &[Symbol] = &[sym::coverage];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const TEMPLATE: AttributeTemplate = template!(OneOf: &[sym::off, sym::on]);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let Some(args) = args.list() else {
+            cx.expected_specific_argument_and_list(cx.attr_span, vec!["on", "off"]);
+            return None;
+        };
+
+        let Some(arg) = args.single() else {
+            cx.expected_single_argument(args.span);
+            return None;
+        };
+
+        let fail_incorrect_argument = |span| cx.expected_specific_argument(span, vec!["on", "off"]);
+
+        let Some(arg) = arg.meta_item() else {
+            fail_incorrect_argument(args.span);
+            return None;
+        };
+
+        let status = match arg.path().word_sym() {
+            Some(sym::off) => CoverageStatus::Off,
+            Some(sym::on) => CoverageStatus::On,
+            None | Some(_) => {
+                fail_incorrect_argument(arg.span());
+                return None;
+            }
+        };
+
+        Some(AttributeKind::Coverage(cx.attr_span, status))
+    }
+}
+
 pub(crate) struct ExportNameParser;
 
 impl<S: Stage> SingleAttributeParser<S> for ExportNameParser {
diff --git a/compiler/rustc_attr_parsing/src/attributes/stability.rs b/compiler/rustc_attr_parsing/src/attributes/stability.rs
index 6bccd0042a8..59337749c87 100644
--- a/compiler/rustc_attr_parsing/src/attributes/stability.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/stability.rs
@@ -98,6 +98,16 @@ impl<S: Stage> AttributeParser<S> for StabilityParser {
             }
         }
 
+        if let Some((Stability { level: StabilityLevel::Stable { .. }, .. }, _)) = self.stability {
+            for other_attr in cx.all_attrs {
+                if other_attr.word_is(sym::unstable_feature_bound) {
+                    cx.emit_err(session_diagnostics::UnstableFeatureBoundIncompatibleStability {
+                        span: cx.target_span,
+                    });
+                }
+            }
+        }
+
         let (stability, span) = self.stability?;
 
         Some(AttributeKind::Stability { stability, span })
@@ -282,12 +292,12 @@ pub(crate) fn parse_stability<S: Stage>(
         } else if let Some(version) = parse_version(since) {
             StableSince::Version(version)
         } else {
-            cx.emit_err(session_diagnostics::InvalidSince { span: cx.attr_span });
-            StableSince::Err
+            let err = cx.emit_err(session_diagnostics::InvalidSince { span: cx.attr_span });
+            StableSince::Err(err)
         }
     } else {
-        cx.emit_err(session_diagnostics::MissingSince { span: cx.attr_span });
-        StableSince::Err
+        let err = cx.emit_err(session_diagnostics::MissingSince { span: cx.attr_span });
+        StableSince::Err(err)
     };
 
     match feature {
diff --git a/compiler/rustc_attr_parsing/src/attributes/traits.rs b/compiler/rustc_attr_parsing/src/attributes/traits.rs
index d5e088effd5..e69a533699b 100644
--- a/compiler/rustc_attr_parsing/src/attributes/traits.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/traits.rs
@@ -91,6 +91,7 @@ impl<S: Stage> NoArgsAttributeParser<S> for DoNotImplementViaObjectParser {
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::DoNotImplementViaObject;
 }
 
+// FIXME(const_trait_impl): remove this
 // Const traits
 
 pub(crate) struct ConstTraitParser;
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 567341d1517..4d692d9562c 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -13,10 +13,13 @@ use rustc_hir::{AttrArgs, AttrItem, AttrPath, Attribute, HashIgnoredAttrId, HirI
 use rustc_session::Session;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 
-use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
+use crate::attributes::allow_unstable::{
+    AllowConstFnUnstableParser, AllowInternalUnstableParser, UnstableFeatureBoundParser,
+};
 use crate::attributes::codegen_attrs::{
-    ColdParser, ExportNameParser, NakedParser, NoMangleParser, OmitGdbPrettyPrinterSectionParser,
-    OptimizeParser, TargetFeatureParser, TrackCallerParser, UsedParser,
+    ColdParser, CoverageParser, ExportNameParser, NakedParser, NoMangleParser,
+    OmitGdbPrettyPrinterSectionParser, OptimizeParser, TargetFeatureParser, TrackCallerParser,
+    UsedParser,
 };
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
@@ -133,9 +136,11 @@ attribute_parsers!(
         Combine<AllowInternalUnstableParser>,
         Combine<ReprParser>,
         Combine<TargetFeatureParser>,
+        Combine<UnstableFeatureBoundParser>,
         // tidy-alphabetical-end
 
         // tidy-alphabetical-start
+        Single<CoverageParser>,
         Single<DeprecationParser>,
         Single<DummyParser>,
         Single<ExportNameParser>,
@@ -223,7 +228,7 @@ impl Stage for Early {
         sess: &'sess Session,
         diag: impl for<'x> Diagnostic<'x>,
     ) -> ErrorGuaranteed {
-        if self.emit_errors {
+        if self.emit_errors.should_emit() {
             sess.dcx().emit_err(diag)
         } else {
             sess.dcx().create_err(diag).delay_as_bug()
@@ -254,7 +259,7 @@ pub struct Early {
     /// Whether to emit errors or delay them as a bug
     /// For most attributes, the attribute will be parsed again in the `Late` stage and in this case the errors should be delayed
     /// But for some, such as `cfg`, the attribute will be removed before the `Late` stage so errors must be emitted
-    pub emit_errors: bool,
+    pub emit_errors: ShouldEmit,
 }
 /// used when parsing attributes during ast lowering
 pub struct Late;
@@ -449,6 +454,25 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             reason: AttributeParseErrorReason::ExpectedSpecificArgument {
                 possibilities,
                 strings: false,
+                list: false,
+            },
+        })
+    }
+
+    pub(crate) fn expected_specific_argument_and_list(
+        &self,
+        span: Span,
+        possibilities: Vec<&'static str>,
+    ) -> ErrorGuaranteed {
+        self.emit_err(AttributeParseError {
+            span,
+            attr_span: self.attr_span,
+            template: self.template.clone(),
+            attribute: self.attr_path.clone(),
+            reason: AttributeParseErrorReason::ExpectedSpecificArgument {
+                possibilities,
+                strings: false,
+                list: true,
             },
         })
     }
@@ -466,6 +490,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             reason: AttributeParseErrorReason::ExpectedSpecificArgument {
                 possibilities,
                 strings: true,
+                list: false,
             },
         })
     }
@@ -555,6 +580,25 @@ pub enum OmitDoc {
     Skip,
 }
 
+#[derive(Copy, Clone)]
+pub enum ShouldEmit {
+    /// The operation will emit errors and lints.
+    /// This is usually what you need.
+    ErrorsAndLints,
+    /// The operation will emit *not* errors and lints.
+    /// Use this if you are *sure* that this operation will be called at a different time with `ShouldEmit::Emit`.
+    Nothing,
+}
+
+impl ShouldEmit {
+    pub fn should_emit(&self) -> bool {
+        match self {
+            ShouldEmit::ErrorsAndLints => true,
+            ShouldEmit::Nothing => false,
+        }
+    }
+}
+
 /// Context created once, for example as part of the ast lowering
 /// context, through which all attributes can be lowered.
 pub struct AttributeParser<'sess, S: Stage = Late> {
@@ -597,7 +641,7 @@ impl<'sess> AttributeParser<'sess, Early> {
             tools: Vec::new(),
             parse_only: Some(sym),
             sess,
-            stage: Early { emit_errors: false },
+            stage: Early { emit_errors: ShouldEmit::Nothing },
         };
         let mut parsed = p.parse_attribute_list(
             attrs,
@@ -620,7 +664,7 @@ impl<'sess> AttributeParser<'sess, Early> {
         target_span: Span,
         target_node_id: NodeId,
         features: Option<&'sess Features>,
-        emit_errors: bool,
+        emit_errors: ShouldEmit,
         parse_fn: fn(cx: &mut AcceptContext<'_, '_, Early>, item: &ArgParser<'_>) -> T,
         template: &AttributeTemplate,
     ) -> T {
diff --git a/compiler/rustc_attr_parsing/src/lib.rs b/compiler/rustc_attr_parsing/src/lib.rs
index 2102a26108b..dc54cb6b840 100644
--- a/compiler/rustc_attr_parsing/src/lib.rs
+++ b/compiler/rustc_attr_parsing/src/lib.rs
@@ -95,7 +95,7 @@ pub use attributes::cfg_old::*;
 pub use attributes::util::{
     find_crate_name, is_builtin_attr, is_doc_alias_attrs_contain_symbol, parse_version,
 };
-pub use context::{AttributeParser, Early, Late, OmitDoc};
+pub use context::{AttributeParser, Early, Late, OmitDoc, ShouldEmit};
 pub use lints::emit_attribute_lint;
 
 rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
diff --git a/compiler/rustc_attr_parsing/src/session_diagnostics.rs b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
index 97bf3d1c549..9a400e0fe10 100644
--- a/compiler/rustc_attr_parsing/src/session_diagnostics.rs
+++ b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
@@ -504,6 +504,14 @@ pub(crate) struct UnrecognizedReprHint {
 }
 
 #[derive(Diagnostic)]
+#[diag(attr_parsing_unstable_feature_bound_incompatible_stability)]
+#[help]
+pub(crate) struct UnstableFeatureBoundIncompatibleStability {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
 #[diag(attr_parsing_naked_functions_incompatible_attribute, code = E0736)]
 pub(crate) struct NakedFunctionIncompatibleAttribute {
     #[primary_span]
@@ -525,7 +533,9 @@ pub(crate) struct LinkOrdinalOutOfRange {
 
 pub(crate) enum AttributeParseErrorReason {
     ExpectedNoArgs,
-    ExpectedStringLiteral { byte_string: Option<Span> },
+    ExpectedStringLiteral {
+        byte_string: Option<Span>,
+    },
     ExpectedIntegerLiteral,
     ExpectedAtLeastOneArgument,
     ExpectedSingleArgument,
@@ -533,7 +543,12 @@ pub(crate) enum AttributeParseErrorReason {
     UnexpectedLiteral,
     ExpectedNameValue(Option<Symbol>),
     DuplicateKey(Symbol),
-    ExpectedSpecificArgument { possibilities: Vec<&'static str>, strings: bool },
+    ExpectedSpecificArgument {
+        possibilities: Vec<&'static str>,
+        strings: bool,
+        /// Should we tell the user to write a list when they didn't?
+        list: bool,
+    },
 }
 
 pub(crate) struct AttributeParseError {
@@ -607,7 +622,11 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError {
                     format!("expected this to be of the form `{name} = \"...\"`"),
                 );
             }
-            AttributeParseErrorReason::ExpectedSpecificArgument { possibilities, strings } => {
+            AttributeParseErrorReason::ExpectedSpecificArgument {
+                possibilities,
+                strings,
+                list: false,
+            } => {
                 let quote = if strings { '"' } else { '`' };
                 match possibilities.as_slice() {
                     &[] => {}
@@ -633,6 +652,38 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError {
                     }
                 }
             }
+            AttributeParseErrorReason::ExpectedSpecificArgument {
+                possibilities,
+                strings,
+                list: true,
+            } => {
+                let quote = if strings { '"' } else { '`' };
+                match possibilities.as_slice() {
+                    &[] => {}
+                    &[x] => {
+                        diag.span_label(
+                            self.span,
+                            format!(
+                                "this attribute is only valid with {quote}{x}{quote} as an argument"
+                            ),
+                        );
+                    }
+                    [first, second] => {
+                        diag.span_label(self.span, format!("this attribute is only valid with either {quote}{first}{quote} or {quote}{second}{quote} as an argument"));
+                    }
+                    [first @ .., second_to_last, last] => {
+                        let mut res = String::new();
+                        for i in first {
+                            res.push_str(&format!("{quote}{i}{quote}, "));
+                        }
+                        res.push_str(&format!(
+                            "{quote}{second_to_last}{quote} or {quote}{last}{quote}"
+                        ));
+
+                        diag.span_label(self.span, format!("this attribute is only valid with one of the following arguments: {res}"));
+                    }
+                }
+            }
         }
 
         let suggestions = self.template.suggestions(false, &name);