Rollup of 6 pull requests

compiler/rustc_attr/src/builtin.rs

@@ -15,6 +15,12 @@ use std::num::NonZeroU32;
 
 use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
 
+/// The version placeholder that recently stabilized features contain inside the
+/// `since` field of the `#[stable]` attribute.
+///
+/// For more, see [this pull request](https://github.com/rust-lang/rust/pull/100591).
+pub const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
+
 pub fn is_builtin_attr(attr: &Attribute) -> bool {
     attr.is_doc_comment() || attr.ident().filter(|ident| is_builtin_attr_name(ident.name)).is_some()
 }
@@ -483,6 +489,12 @@ where
                         }
                     }
 
+                    if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
+                        let version = option_env!("CFG_VERSION").unwrap_or("<current>");
+                        let version = version.split(' ').next().unwrap();
+                        since = Some(Symbol::intern(&version));
+                    }
+
                     match (feature, since) {
                         (Some(feature), Some(since)) => {
                             let level = Stable { since, allowed_through_unstable_modules: false };

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -2797,20 +2797,24 @@ fn add_gcc_ld_path(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) {
         if let LinkerFlavor::Gcc = flavor {
             match ld_impl {
                 LdImpl::Lld => {
-                    let tools_path = sess.get_tools_search_paths(false);
-                    let gcc_ld_dir = tools_path
-                        .into_iter()
-                        .map(|p| p.join("gcc-ld"))
-                        .find(|p| {
-                            p.join(if sess.host.is_like_windows { "ld.exe" } else { "ld" }).exists()
-                        })
-                        .unwrap_or_else(|| sess.fatal("rust-lld (as ld) not found"));
-                    cmd.arg({
-                        let mut arg = OsString::from("-B");
-                        arg.push(gcc_ld_dir);
-                        arg
-                    });
-                    cmd.arg(format!("-Wl,-rustc-lld-flavor={}", sess.target.lld_flavor.as_str()));
+                    // Implement the "self-contained" part of -Zgcc-ld
+                    // by adding rustc distribution directories to the tool search path.
+                    for path in sess.get_tools_search_paths(false) {
+                        cmd.arg({
+                            let mut arg = OsString::from("-B");
+                            arg.push(path.join("gcc-ld"));
+                            arg
+                        });
+                    }
+                    // Implement the "linker flavor" part of -Zgcc-ld
+                    // by asking cc to use some kind of lld.
+                    cmd.arg("-fuse-ld=lld");
+                    if sess.target.lld_flavor != LldFlavor::Ld {
+                        // Tell clang to use a non-default LLD flavor.
+                        // Gcc doesn't understand the target option, but we currently assume
+                        // that gcc is not used for Apple and Wasm targets (#97402).
+                        cmd.arg(format!("--target={}", sess.target.llvm_target));
+                    }
                 }
             }
         } else {

compiler/rustc_const_eval/src/transform/validate.rs

@@ -181,16 +181,23 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         if (src, dest).has_opaque_types() {
             return true;
         }
-        // Normalize projections and things like that.
-        let param_env = self.param_env.with_reveal_all_normalized(self.tcx);
-        let src = self.tcx.normalize_erasing_regions(param_env, src);
-        let dest = self.tcx.normalize_erasing_regions(param_env, dest);
 
+        // Normalize projections and things like that.
         // Type-changing assignments can happen when subtyping is used. While
         // all normal lifetimes are erased, higher-ranked types with their
         // late-bound lifetimes are still around and can lead to type
         // differences. So we compare ignoring lifetimes.
-        equal_up_to_regions(self.tcx, param_env, src, dest)
+
+        // First, try with reveal_all. This might not work in some cases, as the predicates
+        // can be cleared in reveal_all mode. We try the reveal first anyways as it is used
+        // by some other passes like inlining as well.
+        let param_env = self.param_env.with_reveal_all_normalized(self.tcx);
+        if equal_up_to_regions(self.tcx, param_env, src, dest) {
+            return true;
+        }
+
+        // If this fails, we can try it without the reveal.
+        equal_up_to_regions(self.tcx, self.param_env, src, dest)
     }
 }
 

compiler/rustc_error_messages/locales/en-US/trait_selection.ftl

@@ -0,0 +1,26 @@
+trait_selection_dump_vtable_entries = vtable entries for `{$trait_ref}`: {$entries}
+
+trait_selection_unable_to_construct_constant_value = unable to construct a constant value for the unevaluated constant {$unevaluated}
+
+trait_selection_auto_deref_reached_recursion_limit = reached the recursion limit while auto-dereferencing `{$ty}`
+    .label = deref recursion limit reached
+    .help = consider increasing the recursion limit by adding a `#![recursion_limit = "{$suggested_limit}"]` attribute to your crate (`{$crate_name}`)
+
+trait_selection_empty_on_clause_in_rustc_on_unimplemented = empty `on`-clause in `#[rustc_on_unimplemented]`
+    .label = empty on-clause here
+
+trait_selection_invalid_on_clause_in_rustc_on_unimplemented = invalid `on`-clause in `#[rustc_on_unimplemented]`
+    .label = invalid on-clause here
+
+trait_selection_no_value_in_rustc_on_unimplemented = this attribute must have a valid value
+    .label = expected value here
+    .note = eg `#[rustc_on_unimplemented(message="foo")]`
+
+trait_selection_negative_positive_conflict = found both positive and negative implementation of trait `{$trait_desc}`{$self_desc ->
+        [none] {""}
+       *[default] {" "}for type `{$self_desc}`
+    }:
+    .negative_implementation_here = negative implementation here
+    .negative_implementation_in_crate = negative implementation in crate `{$negative_impl_cname}`
+    .positive_implementation_here = positive implementation here
+    .positive_implementation_in_crate = positive implementation in crate `{$positive_impl_cname}`

compiler/rustc_error_messages/src/lib.rs

@@ -53,6 +53,7 @@ fluent_messages! {
     plugin_impl => "../locales/en-US/plugin_impl.ftl",
     privacy => "../locales/en-US/privacy.ftl",
     query_system => "../locales/en-US/query_system.ftl",
+    trait_selection => "../locales/en-US/trait_selection.ftl",
     save_analysis => "../locales/en-US/save_analysis.ftl",
     ty_utils => "../locales/en-US/ty_utils.ftl",
     typeck => "../locales/en-US/typeck.ftl",

compiler/rustc_middle/src/ty/consts/kind.rs

@@ -20,6 +20,12 @@ pub struct Unevaluated<'tcx, P = Option<Promoted>> {
     pub promoted: P,
 }
 
+impl rustc_errors::IntoDiagnosticArg for Unevaluated<'_> {
+    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
+        format!("{:?}", self).into_diagnostic_arg()
+    }
+}
+
 impl<'tcx> Unevaluated<'tcx> {
     #[inline]
     pub fn shrink(self) -> Unevaluated<'tcx, ()> {

compiler/rustc_middle/src/ty/sty.rs

@@ -849,6 +849,12 @@ impl<'tcx> PolyTraitRef<'tcx> {
     }
 }
 
+impl rustc_errors::IntoDiagnosticArg for PolyTraitRef<'_> {
+    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
+        self.to_string().into_diagnostic_arg()
+    }
+}
+
 /// An existential reference to a trait, where `Self` is erased.
 /// For example, the trait object `Trait<'a, 'b, X, Y>` is:
 /// ```ignore (illustrative)

compiler/rustc_passes/src/lib_features.rs

@@ -5,6 +5,7 @@
 //! collect them instead.
 
 use rustc_ast::{Attribute, MetaItemKind};
+use rustc_attr::VERSION_PLACEHOLDER;
 use rustc_errors::struct_span_err;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
@@ -54,7 +55,6 @@ impl<'tcx> LibFeatureCollector<'tcx> {
                         }
                     }
                 }
-                const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
 
                 if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
                     let version = option_env!("CFG_VERSION").unwrap_or("<current>");

compiler/rustc_session/src/session.rs

@@ -110,6 +110,12 @@ impl Mul<usize> for Limit {
     }
 }
 
+impl rustc_errors::IntoDiagnosticArg for Limit {
+    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
+        self.to_string().into_diagnostic_arg()
+    }
+}
+
 #[derive(Clone, Copy, Debug, HashStable_Generic)]
 pub struct Limits {
     /// The maximum recursion limit for potentially infinitely recursive

compiler/rustc_trait_selection/src/autoderef.rs

@@ -1,6 +1,6 @@
+use crate::errors::AutoDerefReachedRecursionLimit;
 use crate::traits::query::evaluate_obligation::InferCtxtExt;
 use crate::traits::{self, TraitEngine};
-use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::ty::{self, TraitRef, Ty, TyCtxt};
@@ -222,19 +222,10 @@ pub fn report_autoderef_recursion_limit_error<'tcx>(tcx: TyCtxt<'tcx>, span: Spa
         Limit(0) => Limit(2),
         limit => limit * 2,
     };
-    struct_span_err!(
-        tcx.sess,
+    tcx.sess.emit_err(AutoDerefReachedRecursionLimit {
         span,
-        E0055,
-        "reached the recursion limit while auto-dereferencing `{:?}`",
-        ty
-    )
-    .span_label(span, "deref recursion limit reached")
-    .help(&format!(
-        "consider increasing the recursion limit by adding a \
-             `#![recursion_limit = \"{}\"]` attribute to your crate (`{}`)",
+        ty,
         suggested_limit,
-        tcx.crate_name(LOCAL_CRATE),
-    ))
-    .emit();
+        crate_name: tcx.crate_name(LOCAL_CRATE),
+    });
 }

compiler/rustc_trait_selection/src/errors.rs

@@ -0,0 +1,102 @@
+use rustc_errors::{fluent, ErrorGuaranteed};
+use rustc_macros::SessionDiagnostic;
+use rustc_middle::ty::{PolyTraitRef, Ty, Unevaluated};
+use rustc_session::{parse::ParseSess, Limit, SessionDiagnostic};
+use rustc_span::{Span, Symbol};
+
+#[derive(SessionDiagnostic)]
+#[diag(trait_selection::dump_vtable_entries)]
+pub struct DumpVTableEntries<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub trait_ref: PolyTraitRef<'a>,
+    pub entries: String,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(trait_selection::unable_to_construct_constant_value)]
+pub struct UnableToConstructConstantValue<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub unevaluated: Unevaluated<'a>,
+}
+
+#[derive(SessionDiagnostic)]
+#[help]
+#[diag(trait_selection::auto_deref_reached_recursion_limit, code = "E0055")]
+pub struct AutoDerefReachedRecursionLimit<'a> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub ty: Ty<'a>,
+    pub suggested_limit: Limit,
+    pub crate_name: Symbol,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(trait_selection::empty_on_clause_in_rustc_on_unimplemented, code = "E0232")]
+pub struct EmptyOnClauseInOnUnimplemented {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(trait_selection::invalid_on_clause_in_rustc_on_unimplemented, code = "E0232")]
+pub struct InvalidOnClauseInOnUnimplemented {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(trait_selection::no_value_in_rustc_on_unimplemented, code = "E0232")]
+#[note]
+pub struct NoValueInOnUnimplemented {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+}
+
+pub struct NegativePositiveConflict<'a> {
+    pub impl_span: Span,
+    pub trait_desc: &'a str,
+    pub self_desc: &'a Option<String>,
+    pub negative_impl_span: Result<Span, Symbol>,
+    pub positive_impl_span: Result<Span, Symbol>,
+}
+
+impl SessionDiagnostic<'_> for NegativePositiveConflict<'_> {
+    fn into_diagnostic(
+        self,
+        sess: &ParseSess,
+    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
+        let mut diag = sess.struct_err(fluent::trait_selection::negative_positive_conflict);
+        diag.set_arg("trait_desc", self.trait_desc);
+        diag.set_arg(
+            "self_desc",
+            self.self_desc.clone().map_or_else(|| String::from("none"), |ty| ty),
+        );
+        diag.set_span(self.impl_span);
+        diag.code(rustc_errors::error_code!(E0751));
+        match self.negative_impl_span {
+            Ok(span) => {
+                diag.span_label(span, fluent::trait_selection::negative_implementation_here);
+            }
+            Err(cname) => {
+                diag.note(fluent::trait_selection::negative_implementation_in_crate);
+                diag.set_arg("negative_impl_cname", cname.to_string());
+            }
+        }
+        match self.positive_impl_span {
+            Ok(span) => {
+                diag.span_label(span, fluent::trait_selection::positive_implementation_here);
+            }
+            Err(cname) => {
+                diag.note(fluent::trait_selection::positive_implementation_in_crate);
+                diag.set_arg("positive_impl_cname", cname.to_string());
+            }
+        }
+        diag
+    }
+}

compiler/rustc_trait_selection/src/lib.rs

@@ -37,5 +37,6 @@ extern crate rustc_middle;
 extern crate smallvec;
 
 pub mod autoderef;
+pub mod errors;
 pub mod infer;
 pub mod traits;

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -3,6 +3,7 @@
 
 use super::*;
 
+use crate::errors::UnableToConstructConstantValue;
 use crate::infer::region_constraints::{Constraint, RegionConstraintData};
 use crate::infer::InferCtxt;
 use crate::traits::project::ProjectAndUnifyResult;
@@ -830,8 +831,11 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                                 Ok(None) => {
                                     let tcx = self.tcx;
                                     let def_id = unevaluated.def.did;
-                                    let reported = tcx.sess.struct_span_err(tcx.def_span(def_id), &format!("unable to construct a constant value for the unevaluated constant {:?}", unevaluated)).emit();
-
+                                    let reported =
+                                        tcx.sess.emit_err(UnableToConstructConstantValue {
+                                            span: tcx.def_span(def_id),
+                                            unevaluated,
+                                        });
                                     Err(ErrorHandled::Reported(reported))
                                 }
                                 Err(err) => Err(err),

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -23,6 +23,7 @@ mod structural_match;
 mod util;
 pub mod wf;
 
+use crate::errors::DumpVTableEntries;
 use crate::infer::outlives::env::OutlivesEnvironment;
 use crate::infer::{InferCtxt, TyCtxtInferExt};
 use crate::traits::error_reporting::InferCtxtExt as _;
@@ -763,8 +764,11 @@ fn dump_vtable_entries<'tcx>(
     trait_ref: ty::PolyTraitRef<'tcx>,
     entries: &[VtblEntry<'tcx>],
 ) {
-    let msg = format!("vtable entries for `{}`: {:#?}", trait_ref, entries);
-    tcx.sess.struct_span_err(sp, &msg).emit();
+    tcx.sess.emit_err(DumpVTableEntries {
+        span: sp,
+        trait_ref,
+        entries: format!("{:#?}", entries),
+    });
 }
 
 fn own_existential_vtable_entries<'tcx>(