Rollup of 4 pull requests

Cargo.lock

@@ -3505,6 +3505,7 @@ dependencies = [
  "rand_xoshiro",
  "rustc_data_structures",
  "rustc_error_messages",
+ "rustc_errors",
  "rustc_hashes",
  "rustc_index",
  "rustc_macros",
@@ -3909,7 +3910,6 @@ dependencies = [
  "anstream",
  "anstyle",
  "derive_setters",
- "rustc_abi",
  "rustc_ast",
  "rustc_data_structures",
  "rustc_error_codes",

compiler/rustc_abi/Cargo.toml

@@ -10,6 +10,7 @@ rand = { version = "0.9.0", default-features = false, optional = true }
 rand_xoshiro = { version = "0.7.0", optional = true }
 rustc_data_structures = { path = "../rustc_data_structures", optional = true }
 rustc_error_messages = { path = "../rustc_error_messages", optional = true }
+rustc_errors = { path = "../rustc_errors", optional = true }
 rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index", default-features = false }
 rustc_macros = { path = "../rustc_macros", optional = true }
@@ -21,11 +22,12 @@ tracing = "0.1"
 [features]
 # tidy-alphabetical-start
 default = ["nightly", "randomize"]
-# rust-analyzer depends on this crate and we therefore require it to built on a stable toolchain
-# without depending on rustc_data_structures, rustc_macros and rustc_serialize
+# rust-analyzer depends on this crate and we therefore require it to build on a stable toolchain
+# without depending on the rustc_* crates in the following list.
 nightly = [
     "dep:rustc_data_structures",
     "dep:rustc_error_messages",
+    "dep:rustc_errors",
     "dep:rustc_macros",
     "dep:rustc_serialize",
     "dep:rustc_span",

compiler/rustc_abi/src/lib.rs

@@ -46,6 +46,8 @@ use std::str::FromStr;
 use bitflags::bitflags;
 #[cfg(feature = "nightly")]
 use rustc_data_structures::stable_hasher::StableOrd;
+#[cfg(feature = "nightly")]
+use rustc_errors::{Diag, DiagCtxtHandle, Diagnostic, EmissionGuarantee, Level, msg};
 use rustc_hashes::Hash64;
 use rustc_index::{Idx, IndexSlice, IndexVec};
 #[cfg(feature = "nightly")]
@@ -332,7 +334,7 @@ impl Default for TargetDataLayout {
     }
 }
 
-pub enum TargetDataLayoutErrors<'a> {
+pub enum TargetDataLayoutError<'a> {
     InvalidAddressSpace { addr_space: &'a str, cause: &'a str, err: ParseIntError },
     InvalidBits { kind: &'a str, bit: &'a str, cause: &'a str, err: ParseIntError },
     MissingAlignment { cause: &'a str },
@@ -343,6 +345,51 @@ pub enum TargetDataLayoutErrors<'a> {
     UnknownPointerSpecification { err: String },
 }
 
+#[cfg(feature = "nightly")]
+impl<G: EmissionGuarantee> Diagnostic<'_, G> for TargetDataLayoutError<'_> {
+    fn into_diag(self, dcx: DiagCtxtHandle<'_>, level: Level) -> Diag<'_, G> {
+        match self {
+            TargetDataLayoutError::InvalidAddressSpace { addr_space, err, cause } => {
+                Diag::new(dcx, level, msg!("invalid address space `{$addr_space}` for `{$cause}` in \"data-layout\": {$err}"))
+                    .with_arg("addr_space", addr_space)
+                    .with_arg("cause", cause)
+                    .with_arg("err", err)
+            }
+            TargetDataLayoutError::InvalidBits { kind, bit, cause, err } => {
+                Diag::new(dcx, level, msg!("invalid {$kind} `{$bit}` for `{$cause}` in \"data-layout\": {$err}"))
+                    .with_arg("kind", kind)
+                    .with_arg("bit", bit)
+                    .with_arg("cause", cause)
+                    .with_arg("err", err)
+            }
+            TargetDataLayoutError::MissingAlignment { cause } => {
+                Diag::new(dcx, level, msg!("missing alignment for `{$cause}` in \"data-layout\""))
+                    .with_arg("cause", cause)
+            }
+            TargetDataLayoutError::InvalidAlignment { cause, err } => {
+                Diag::new(dcx, level, msg!("invalid alignment for `{$cause}` in \"data-layout\": {$err}"))
+                    .with_arg("cause", cause)
+                    .with_arg("err", err.to_string())
+            }
+            TargetDataLayoutError::InconsistentTargetArchitecture { dl, target } => {
+                Diag::new(dcx, level, msg!("inconsistent target specification: \"data-layout\" claims architecture is {$dl}-endian, while \"target-endian\" is `{$target}`"))
+                    .with_arg("dl", dl).with_arg("target", target)
+            }
+            TargetDataLayoutError::InconsistentTargetPointerWidth { pointer_size, target } => {
+                Diag::new(dcx, level, msg!("inconsistent target specification: \"data-layout\" claims pointers are {$pointer_size}-bit, while \"target-pointer-width\" is `{$target}`"))
+                    .with_arg("pointer_size", pointer_size).with_arg("target", target)
+            }
+            TargetDataLayoutError::InvalidBitsSize { err } => {
+                Diag::new(dcx, level, msg!("{$err}")).with_arg("err", err)
+            }
+            TargetDataLayoutError::UnknownPointerSpecification { err } => {
+                Diag::new(dcx, level, msg!("unknown pointer specification `{$err}` in datalayout string"))
+                    .with_arg("err", err)
+            }
+        }
+    }
+}
+
 impl TargetDataLayout {
     /// Parse data layout from an
     /// [llvm data layout string](https://llvm.org/docs/LangRef.html#data-layout)
@@ -352,17 +399,17 @@ impl TargetDataLayout {
     pub fn parse_from_llvm_datalayout_string<'a>(
         input: &'a str,
         default_address_space: AddressSpace,
-    ) -> Result<TargetDataLayout, TargetDataLayoutErrors<'a>> {
+    ) -> Result<TargetDataLayout, TargetDataLayoutError<'a>> {
         // Parse an address space index from a string.
         let parse_address_space = |s: &'a str, cause: &'a str| {
             s.parse::<u32>().map(AddressSpace).map_err(|err| {
-                TargetDataLayoutErrors::InvalidAddressSpace { addr_space: s, cause, err }
+                TargetDataLayoutError::InvalidAddressSpace { addr_space: s, cause, err }
             })
         };
 
         // Parse a bit count from a string.
         let parse_bits = |s: &'a str, kind: &'a str, cause: &'a str| {
-            s.parse::<u64>().map_err(|err| TargetDataLayoutErrors::InvalidBits {
+            s.parse::<u64>().map_err(|err| TargetDataLayoutError::InvalidBits {
                 kind,
                 bit: s,
                 cause,
@@ -378,7 +425,7 @@ impl TargetDataLayout {
         let parse_align_str = |s: &'a str, cause: &'a str| {
             let align_from_bits = |bits| {
                 Align::from_bits(bits)
-                    .map_err(|err| TargetDataLayoutErrors::InvalidAlignment { cause, err })
+                    .map_err(|err| TargetDataLayoutError::InvalidAlignment { cause, err })
             };
             let abi = parse_bits(s, "alignment", cause)?;
             Ok(align_from_bits(abi)?)
@@ -388,7 +435,7 @@ impl TargetDataLayout {
         // ignoring the secondary alignment specifications.
         let parse_align_seq = |s: &[&'a str], cause: &'a str| {
             if s.is_empty() {
-                return Err(TargetDataLayoutErrors::MissingAlignment { cause });
+                return Err(TargetDataLayoutError::MissingAlignment { cause });
             }
             parse_align_str(s[0], cause)
         };
@@ -426,7 +473,7 @@ impl TargetDataLayout {
                     // However, we currently don't take into account further specifications:
                     // an error is emitted instead.
                     if p.starts_with(char::is_alphabetic) {
-                        return Err(TargetDataLayoutErrors::UnknownPointerSpecification {
+                        return Err(TargetDataLayoutError::UnknownPointerSpecification {
                             err: p.to_string(),
                         });
                     }
@@ -471,7 +518,7 @@ impl TargetDataLayout {
                     // However, we currently don't take into account further specifications:
                     // an error is emitted instead.
                     if p.starts_with(char::is_alphabetic) {
-                        return Err(TargetDataLayoutErrors::UnknownPointerSpecification {
+                        return Err(TargetDataLayoutError::UnknownPointerSpecification {
                             err: p.to_string(),
                         });
                     }

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -649,7 +649,7 @@ fn maybe_stage_features(sess: &Session, features: &Features, krate: &ast::Crate)
         AttributeParser::parse_limited(
             sess,
             &krate.attrs,
-            sym::feature,
+            &[sym::feature],
             DUMMY_SP,
             krate.id,
             Some(&features),

compiler/rustc_attr_parsing/src/attributes/diagnostic/mod.rs

@@ -24,6 +24,7 @@ pub(crate) mod do_not_recommend;
 pub(crate) mod on_const;
 pub(crate) mod on_move;
 pub(crate) mod on_unimplemented;
+pub(crate) mod on_unknown;
 
 #[derive(Copy, Clone)]
 pub(crate) enum Mode {
@@ -35,6 +36,8 @@ pub(crate) enum Mode {
     DiagnosticOnConst,
     /// `#[diagnostic::on_move]`
     DiagnosticOnMove,
+    /// `#[diagnostic::on_unknown]`
+    DiagnosticOnUnknown,
 }
 
 fn merge_directives<S: Stage>(
@@ -122,6 +125,13 @@ fn parse_directive_items<'p, S: Stage>(
                         span,
                     );
                 }
+                Mode::DiagnosticOnUnknown => {
+                    cx.emit_lint(
+                        MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                        AttributeLintKind::MalformedOnUnknownAttr { span },
+                        span,
+                    );
+                }
             }
             continue;
         }}
@@ -140,7 +150,7 @@ fn parse_directive_items<'p, S: Stage>(
                 Mode::RustcOnUnimplemented => {
                     cx.emit_err(NoValueInOnUnimplemented { span: item.span() });
                 }
-                Mode::DiagnosticOnUnimplemented |Mode::DiagnosticOnConst | Mode::DiagnosticOnMove => {
+                Mode::DiagnosticOnUnimplemented |Mode::DiagnosticOnConst | Mode::DiagnosticOnMove | Mode::DiagnosticOnUnknown => {
                     cx.emit_lint(
                         MALFORMED_DIAGNOSTIC_ATTRIBUTES,
                         AttributeLintKind::IgnoredDiagnosticOption {
@@ -176,7 +186,8 @@ fn parse_directive_items<'p, S: Stage>(
                 Ok((f, warnings)) => {
                     for warning in warnings {
                         let (FormatWarning::InvalidSpecifier { span, .. }
-                        | FormatWarning::PositionalArgument { span, .. }) = warning;
+                        | FormatWarning::PositionalArgument { span, .. }
+                        | FormatWarning::DisallowedPlaceholder { span }) = warning;
                         cx.emit_lint(
                             MALFORMED_DIAGNOSTIC_FORMAT_LITERALS,
                             AttributeLintKind::MalformedDiagnosticFormat { warning },
@@ -326,6 +337,10 @@ fn parse_arg(
     is_source_literal: bool,
 ) -> FormatArg {
     let span = slice_span(input_span, arg.position_span.clone(), is_source_literal);
+    if matches!(mode, Mode::DiagnosticOnUnknown) {
+        warnings.push(FormatWarning::DisallowedPlaceholder { span });
+        return FormatArg::AsIs(sym::empty_braces);
+    }
 
     match arg.position {
         // Something like "hello {name}"

compiler/rustc_attr_parsing/src/attributes/diagnostic/on_unknown.rs

@@ -0,0 +1,73 @@
+use rustc_hir::attrs::diagnostic::Directive;
+use rustc_session::lint::builtin::MALFORMED_DIAGNOSTIC_ATTRIBUTES;
+
+use crate::attributes::diagnostic::*;
+use crate::attributes::prelude::*;
+
+#[derive(Default)]
+pub(crate) struct OnUnknownParser {
+    span: Option<Span>,
+    directive: Option<(Span, Directive)>,
+}
+
+impl OnUnknownParser {
+    fn parse<'sess, S: Stage>(
+        &mut self,
+        cx: &mut AcceptContext<'_, 'sess, S>,
+        args: &ArgParser,
+        mode: Mode,
+    ) {
+        if !cx.features().diagnostic_on_unknown() {
+            return;
+        }
+        let span = cx.attr_span;
+        self.span = Some(span);
+
+        let items = match args {
+            ArgParser::List(items) if !items.is_empty() => items,
+            ArgParser::NoArgs | ArgParser::List(_) => {
+                cx.emit_lint(
+                    MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                    AttributeLintKind::MissingOptionsForOnUnknown,
+                    span,
+                );
+                return;
+            }
+            ArgParser::NameValue(_) => {
+                cx.emit_lint(
+                    MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                    AttributeLintKind::MalformedOnUnknownAttr { span },
+                    span,
+                );
+                return;
+            }
+        };
+
+        if let Some(directive) = parse_directive_items(cx, mode, items.mixed(), true) {
+            merge_directives(cx, &mut self.directive, (span, directive));
+        };
+    }
+}
+
+impl<S: Stage> AttributeParser<S> for OnUnknownParser {
+    const ATTRIBUTES: AcceptMapping<Self, S> = &[(
+        &[sym::diagnostic, sym::on_unknown],
+        template!(List: &[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
+        |this, cx, args| {
+            this.parse(cx, args, Mode::DiagnosticOnUnknown);
+        },
+    )];
+    //FIXME attribute is not parsed for non-use statements but diagnostics are issued in `check_attr.rs`
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(ALL_TARGETS);
+
+    fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {
+        if let Some(span) = self.span {
+            Some(AttributeKind::OnUnknown {
+                span,
+                directive: self.directive.map(|d| Box::new(d.1)),
+            })
+        } else {
+            None
+        }
+    }
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -32,6 +32,7 @@ use crate::attributes::diagnostic::do_not_recommend::*;
 use crate::attributes::diagnostic::on_const::*;
 use crate::attributes::diagnostic::on_move::*;
 use crate::attributes::diagnostic::on_unimplemented::*;
+use crate::attributes::diagnostic::on_unknown::*;
 use crate::attributes::doc::*;
 use crate::attributes::dummy::*;
 use crate::attributes::inline::*;
@@ -154,6 +155,7 @@ attribute_parsers!(
         OnConstParser,
         OnMoveParser,
         OnUnimplementedParser,
+        OnUnknownParser,
         RustcAlignParser,
         RustcAlignStaticParser,
         RustcCguTestAttributeParser,

compiler/rustc_attr_parsing/src/interface.rs

@@ -29,7 +29,7 @@ pub struct AttributeParser<'sess, S: Stage = Late> {
     /// *Only* parse attributes with this symbol.
     ///
     /// Used in cases where we want the lowering infrastructure for parse just a single attribute.
-    parse_only: Option<Symbol>,
+    parse_only: Option<&'static [Symbol]>,
 }
 
 impl<'sess> AttributeParser<'sess, Early> {
@@ -50,7 +50,7 @@ impl<'sess> AttributeParser<'sess, Early> {
     pub fn parse_limited(
         sess: &'sess Session,
         attrs: &[ast::Attribute],
-        sym: Symbol,
+        sym: &'static [Symbol],
         target_span: Span,
         target_node_id: NodeId,
         features: Option<&'sess Features>,
@@ -72,7 +72,7 @@ impl<'sess> AttributeParser<'sess, Early> {
     pub fn parse_limited_should_emit(
         sess: &'sess Session,
         attrs: &[ast::Attribute],
-        sym: Symbol,
+        sym: &'static [Symbol],
         target_span: Span,
         target_node_id: NodeId,
         target: Target,
@@ -103,7 +103,7 @@ impl<'sess> AttributeParser<'sess, Early> {
     pub fn parse_limited_all(
         sess: &'sess Session,
         attrs: &[ast::Attribute],
-        parse_only: Option<Symbol>,
+        parse_only: Option<&'static [Symbol]>,
         target: Target,
         target_span: Span,
         target_node_id: NodeId,
@@ -272,7 +272,7 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
         for attr in attrs {
             // If we're only looking for a single attribute, skip all the ones we don't care about.
             if let Some(expected) = self.parse_only {
-                if !attr.has_name(expected) {
+                if !attr.path_matches(expected) {
                     continue;
                 }
             }

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -3538,6 +3538,24 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     Applicability::MaybeIncorrect,
                 );
             }
+
+            if let Some(cow_did) = tcx.get_diagnostic_item(sym::Cow)
+                && let ty::Adt(adt_def, _) = return_ty.kind()
+                && adt_def.did() == cow_did
+            {
+                if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(return_span) {
+                    if let Some(pos) = snippet.rfind(".to_owned") {
+                        let byte_pos = BytePos(pos as u32 + 1u32);
+                        let to_owned_span = return_span.with_hi(return_span.lo() + byte_pos);
+                        err.span_suggestion_short(
+                            to_owned_span.shrink_to_hi(),
+                            "try using `.into_owned()` if you meant to convert a `Cow<'_, T>` to an owned `T`",
+                            "in",
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
+                }
+            }
         }
 
         Err(err)