Auto merge of rust-lang#119987 - matthiaskrgr:rollup-f7lkx4w, r=matth…

…iaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#119818 (Silence some follow-up errors [3/x])
 - rust-lang#119870 (std: Doc blocking behavior of LazyLock)
 - rust-lang#119897 (`OutputTypeParameterMismatch` -> `SignatureMismatch`)
 - rust-lang#119963 (Fix `allow_internal_unstable` for `(min_)specialization`)
 - rust-lang#119971 (Use `zip_eq` to enforce that things being zipped have equal sizes)
 - rust-lang#119974 (Minor `trimmed_def_paths` improvements)

r? `@ghost`
`@rustbot` modify labels: rollup

Cargo.lock

@@ -3879,6 +3879,7 @@ dependencies = [
 name = "rustc_hir_analysis"
 version = "0.0.0"
 dependencies = [
+ "itertools",
  "rustc_arena",
  "rustc_ast",
  "rustc_attr",
@@ -3917,6 +3918,7 @@ dependencies = [
 name = "rustc_hir_typeck"
 version = "0.0.0"
 dependencies = [
+ "itertools",
  "rustc_ast",
  "rustc_attr",
  "rustc_data_structures",
@@ -4200,6 +4202,7 @@ name = "rustc_mir_build"
 version = "0.0.0"
 dependencies = [
  "either",
+ "itertools",
  "rustc_apfloat",
  "rustc_arena",
  "rustc_ast",

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1215,7 +1215,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                     Applicability::MaybeIncorrect,
                                 );
                                 for error in errors {
-                                    if let FulfillmentErrorCode::CodeSelectionError(
+                                    if let FulfillmentErrorCode::SelectionError(
                                         SelectionError::Unimplemented,
                                     ) = error.code
                                         && let ty::PredicateKind::Clause(ty::ClauseKind::Trait(

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -1291,7 +1291,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                                 }
                                 // The type doesn't implement Clone because of unmet obligations.
                                 for error in errors {
-                                    if let traits::FulfillmentErrorCode::CodeSelectionError(
+                                    if let traits::FulfillmentErrorCode::SelectionError(
                                         traits::SelectionError::Unimplemented,
                                     ) = error.code
                                         && let ty::PredicateKind::Clause(ty::ClauseKind::Trait(

compiler/rustc_borrowck/src/type_check/input_output.rs

@@ -7,6 +7,7 @@
 //! `RETURN_PLACE` the MIR arguments) are always fully normalized (and
 //! contain revealed `impl Trait` values).
 
+use itertools::Itertools;
 use rustc_infer::infer::BoundRegionConversionTime;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty};
@@ -39,9 +40,15 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             user_provided_sig,
         );
 
-        for (&user_ty, arg_decl) in user_provided_sig.inputs().iter().zip(
-            // In MIR, closure args begin with an implicit `self`. Skip it!
-            body.args_iter().skip(1).map(|local| &body.local_decls[local]),
+        let is_coroutine_with_implicit_resume_ty = self.tcx().is_coroutine(mir_def_id.to_def_id())
+            && user_provided_sig.inputs().is_empty();
+
+        for (&user_ty, arg_decl) in user_provided_sig.inputs().iter().zip_eq(
+            // In MIR, closure args begin with an implicit `self`.
+            // Also, coroutines have a resume type which may be implicitly `()`.
+            body.args_iter()
+                .skip(1 + if is_coroutine_with_implicit_resume_ty { 1 } else { 0 })
+                .map(|local| &body.local_decls[local]),
         ) {
             self.ascribe_user_type_skip_wf(
                 arg_decl.ty,

compiler/rustc_driver_impl/src/lib.rs

@@ -35,7 +35,7 @@ use rustc_lint::unerased_lint_store;
 use rustc_metadata::creader::MetadataLoader;
 use rustc_metadata::locator;
 use rustc_session::config::{nightly_options, CG_OPTIONS, Z_OPTIONS};
-use rustc_session::config::{ErrorOutputType, Input, OutFileName, OutputType, TrimmedDefPaths};
+use rustc_session::config::{ErrorOutputType, Input, OutFileName, OutputType};
 use rustc_session::getopts::{self, Matches};
 use rustc_session::lint::{Lint, LintId};
 use rustc_session::{config, EarlyDiagCtxt, Session};
@@ -204,7 +204,7 @@ impl Callbacks for TimePassesCallbacks {
         //
         self.time_passes = (config.opts.prints.is_empty() && config.opts.unstable_opts.time_passes)
             .then(|| config.opts.unstable_opts.time_passes_format);
-        config.opts.trimmed_def_paths = TrimmedDefPaths::GoodPath;
+        config.opts.trimmed_def_paths = true;
     }
 }
 

compiler/rustc_hir_analysis/Cargo.toml

@@ -9,6 +9,7 @@ doctest = false
 
 [dependencies]
 # tidy-alphabetical-start
+itertools = "0.11"
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr = { path = "../rustc_attr" }

compiler/rustc_hir_analysis/src/variance/mod.rs

@@ -3,6 +3,7 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/variance.html
 
+use itertools::Itertools;
 use rustc_arena::DroplessArena;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -91,7 +92,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
         fn visit_opaque(&mut self, def_id: DefId, args: GenericArgsRef<'tcx>) -> ControlFlow<!> {
             if def_id != self.root_def_id && self.tcx.is_descendant_of(def_id, self.root_def_id) {
                 let child_variances = self.tcx.variances_of(def_id);
-                for (a, v) in args.iter().zip(child_variances) {
+                for (a, v) in args.iter().zip_eq(child_variances) {
                     if *v != ty::Bivariant {
                         a.visit_with(self)?;
                     }

compiler/rustc_hir_typeck/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
+itertools = "0.11"
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr = { path = "../rustc_attr" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_hir_typeck/src/autoderef.rs

@@ -2,6 +2,7 @@
 use super::method::MethodCallee;
 use super::{FnCtxt, PlaceOp};
 
+use itertools::Itertools;
 use rustc_hir_analysis::autoderef::{Autoderef, AutoderefKind};
 use rustc_infer::infer::InferOk;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, OverloadedDeref};
@@ -32,8 +33,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         autoderef: &Autoderef<'a, 'tcx>,
     ) -> InferOk<'tcx, Vec<Adjustment<'tcx>>> {
-        let mut obligations = vec![];
         let steps = autoderef.steps();
+        if steps.is_empty() {
+            return InferOk { obligations: vec![], value: vec![] };
+        }
+
+        let mut obligations = vec![];
         let targets =
             steps.iter().skip(1).map(|&(ty, _)| ty).chain(iter::once(autoderef.final_ty(false)));
         let steps: Vec<_> = steps
@@ -54,7 +59,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     None
                 }
             })
-            .zip(targets)
+            .zip_eq(targets)
             .map(|(autoderef, target)| Adjustment { kind: Adjust::Deref(autoderef), target })
             .collect();
 

compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs

@@ -86,7 +86,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Finally, for ambiguity-related errors, we actually want to look
         // for a parameter that is the source of the inference type left
         // over in this predicate.
-        if let traits::FulfillmentErrorCode::CodeAmbiguity { .. } = error.code {
+        if let traits::FulfillmentErrorCode::Ambiguity { .. } = error.code {
             fallback_param_to_point_at = None;
             self_param_to_point_at = None;
             param_to_point_at =
@@ -361,10 +361,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         error: &traits::FulfillmentError<'tcx>,
         span: Span,
     ) -> bool {
-        if let traits::FulfillmentErrorCode::CodeSelectionError(
-            traits::SelectionError::OutputTypeParameterMismatch(
-                box traits::SelectionOutputTypeParameterMismatch { expected_trait_ref, .. },
-            ),
+        if let traits::FulfillmentErrorCode::SelectionError(
+            traits::SelectionError::SignatureMismatch(box traits::SignatureMismatchData {
+                expected_trait_ref,
+                ..
+            }),
         ) = error.code
             && let ty::Closure(def_id, _) | ty::Coroutine(def_id, ..) =
                 expected_trait_ref.skip_binder().self_ty().kind()

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -9,6 +9,7 @@ use crate::{
     struct_span_code_err, BreakableCtxt, Diverges, Expectation, FnCtxt, Needs, RawTy,
     TupleArgumentsFlag,
 };
+use itertools::Itertools;
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::{
@@ -421,7 +422,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 formal_input_tys
                     .iter()
                     .copied()
-                    .zip(expected_input_tys.iter().copied())
+                    .zip_eq(expected_input_tys.iter().copied())
                     .map(|vars| self.resolve_vars_if_possible(vars)),
             );
 

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1648,7 +1648,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         }
                     }
                     for error in errors {
-                        if let traits::FulfillmentErrorCode::CodeSelectionError(
+                        if let traits::FulfillmentErrorCode::SelectionError(
                             traits::SelectionError::Unimplemented,
                         ) = error.code
                             && let ty::PredicateKind::Clause(ty::ClauseKind::Trait(pred)) =

compiler/rustc_index_macros/src/lib.rs

@@ -39,6 +39,9 @@ mod newtype;
     feature = "nightly",
     allow_internal_unstable(step_trait, rustc_attrs, trusted_step, spec_option_partial_eq)
 )]
+// FIXME: Remove the above comment about `min_specialization` once bootstrap is bumped,
+// and the corresponding one on SpecOptionPartialEq
+#[cfg_attr(all(feature = "nightly", not(bootstrap)), allow_internal_unstable(min_specialization))]
 pub fn newtype_index(input: TokenStream) -> TokenStream {
     newtype::newtype(input)
 }

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -631,13 +631,6 @@ impl<'tcx> InferCtxt<'tcx> {
                 ct_op: |ct| ct,
             });
 
-            if let ty::ClauseKind::Projection(projection) = predicate.kind().skip_binder() {
-                if projection.term.references_error() {
-                    // No point on adding any obligations since there's a type error involved.
-                    obligations.clear();
-                    return;
-                }
-            }
             // Require that the predicate holds for the concrete type.
             debug!(?predicate);
             obligations.push(traits::Obligation::new(

compiler/rustc_infer/src/traits/mod.rs

@@ -17,7 +17,6 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{self, Const, ToPredicate, Ty, TyCtxt};
 use rustc_span::Span;
 
-pub use self::FulfillmentErrorCode::*;
 pub use self::ImplSource::*;
 pub use self::SelectionError::*;
 
@@ -129,12 +128,12 @@ pub struct FulfillmentError<'tcx> {
 #[derive(Clone)]
 pub enum FulfillmentErrorCode<'tcx> {
     /// Inherently impossible to fulfill; this trait is implemented if and only if it is already implemented.
-    CodeCycle(Vec<PredicateObligation<'tcx>>),
-    CodeSelectionError(SelectionError<'tcx>),
-    CodeProjectionError(MismatchedProjectionTypes<'tcx>),
-    CodeSubtypeError(ExpectedFound<Ty<'tcx>>, TypeError<'tcx>), // always comes from a SubtypePredicate
-    CodeConstEquateError(ExpectedFound<Const<'tcx>>, TypeError<'tcx>),
-    CodeAmbiguity {
+    Cycle(Vec<PredicateObligation<'tcx>>),
+    SelectionError(SelectionError<'tcx>),
+    ProjectionError(MismatchedProjectionTypes<'tcx>),
+    SubtypeError(ExpectedFound<Ty<'tcx>>, TypeError<'tcx>), // always comes from a SubtypePredicate
+    ConstEquateError(ExpectedFound<Const<'tcx>>, TypeError<'tcx>),
+    Ambiguity {
         /// Overflow reported from the new solver `-Znext-solver`, which will
         /// be reported as an regular error as opposed to a fatal error.
         overflow: bool,

compiler/rustc_infer/src/traits/structural_impls.rs

@@ -37,18 +37,19 @@ impl<'tcx> fmt::Debug for traits::FulfillmentError<'tcx> {
 
 impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use traits::FulfillmentErrorCode::*;
         match *self {
-            super::CodeSelectionError(ref e) => write!(f, "{e:?}"),
-            super::CodeProjectionError(ref e) => write!(f, "{e:?}"),
-            super::CodeSubtypeError(ref a, ref b) => {
+            SelectionError(ref e) => write!(f, "{e:?}"),
+            ProjectionError(ref e) => write!(f, "{e:?}"),
+            SubtypeError(ref a, ref b) => {
                 write!(f, "CodeSubtypeError({a:?}, {b:?})")
             }
-            super::CodeConstEquateError(ref a, ref b) => {
+            ConstEquateError(ref a, ref b) => {
                 write!(f, "CodeConstEquateError({a:?}, {b:?})")
             }
-            super::CodeAmbiguity { overflow: false } => write!(f, "Ambiguity"),
-            super::CodeAmbiguity { overflow: true } => write!(f, "Overflow"),
-            super::CodeCycle(ref cycle) => write!(f, "Cycle({cycle:?})"),
+            Ambiguity { overflow: false } => write!(f, "Ambiguity"),
+            Ambiguity { overflow: true } => write!(f, "Overflow"),
+            Cycle(ref cycle) => write!(f, "Cycle({cycle:?})"),
         }
     }
 }

compiler/rustc_middle/src/traits/mod.rs

@@ -604,7 +604,7 @@ pub enum SelectionError<'tcx> {
     /// After a closure impl has selected, its "outputs" were evaluated
     /// (which for closures includes the "input" type params) and they
     /// didn't resolve. See `confirm_poly_trait_refs` for more.
-    OutputTypeParameterMismatch(Box<SelectionOutputTypeParameterMismatch<'tcx>>),
+    SignatureMismatch(Box<SignatureMismatchData<'tcx>>),
     /// The trait pointed by `DefId` is not object safe.
     TraitNotObjectSafe(DefId),
     /// A given constant couldn't be evaluated.
@@ -618,7 +618,7 @@ pub enum SelectionError<'tcx> {
 }
 
 #[derive(Clone, Debug, TypeVisitable)]
-pub struct SelectionOutputTypeParameterMismatch<'tcx> {
+pub struct SignatureMismatchData<'tcx> {
     pub found_trait_ref: ty::PolyTraitRef<'tcx>,
     pub expected_trait_ref: ty::PolyTraitRef<'tcx>,
     pub terr: ty::error::TypeError<'tcx>,

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -15,7 +15,6 @@ use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
 use rustc_hir::def_id::{DefIdMap, DefIdSet, ModDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::definitions::{DefKey, DefPathDataName};
 use rustc_hir::LangItem;
-use rustc_session::config::TrimmedDefPaths;
 use rustc_session::cstore::{ExternCrate, ExternCrateSource};
 use rustc_session::Limit;
 use rustc_span::symbol::{kw, Ident, Symbol};
@@ -365,26 +364,19 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
 
     /// Try to see if this path can be trimmed to a unique symbol name.
     fn try_print_trimmed_def_path(&mut self, def_id: DefId) -> Result<bool, PrintError> {
-        if with_forced_trimmed_paths() {
-            let trimmed = self.force_print_trimmed_def_path(def_id)?;
-            if trimmed {
-                return Ok(true);
-            }
+        if with_forced_trimmed_paths() && self.force_print_trimmed_def_path(def_id)? {
+            return Ok(true);
         }
-        if !self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths
-            || matches!(self.tcx().sess.opts.trimmed_def_paths, TrimmedDefPaths::Never)
-            || with_no_trimmed_paths()
-            || with_crate_prefix()
+        if self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths
+            && self.tcx().sess.opts.trimmed_def_paths
+            && !with_no_trimmed_paths()
+            && !with_crate_prefix()
+            && let Some(symbol) = self.tcx().trimmed_def_paths(()).get(&def_id)
         {
-            return Ok(false);
-        }
-
-        match self.tcx().trimmed_def_paths(()).get(&def_id) {
-            None => Ok(false),
-            Some(symbol) => {
-                write!(self, "{}", Ident::with_dummy_span(*symbol))?;
-                Ok(true)
-            }
+            write!(self, "{}", Ident::with_dummy_span(*symbol))?;
+            Ok(true)
+        } else {
+            Ok(false)
         }
     }
 
@@ -3080,18 +3072,19 @@ fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, N
 /// See also [`DelayDm`](rustc_error_messages::DelayDm) and [`with_no_trimmed_paths!`].
 // this is pub to be able to intra-doc-link it
 pub fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> DefIdMap<Symbol> {
-    let mut map: DefIdMap<Symbol> = Default::default();
-
-    if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths {
-        // Trimming paths is expensive and not optimized, since we expect it to only be used for error reporting.
-        //
-        // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
-        // wrapper can be used to suppress this query, in exchange for full paths being formatted.
-        tcx.sess.good_path_delayed_bug(
-            "trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging",
-        );
-    }
-
+    assert!(tcx.sess.opts.trimmed_def_paths);
+
+    // Trimming paths is expensive and not optimized, since we expect it to only be used for error
+    // reporting.
+    //
+    // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
+    // wrapper can be used to suppress this query, in exchange for full paths being formatted.
+    tcx.sess.good_path_delayed_bug(
+        "trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging",
+    );
+
+    // Once constructed, unique namespace+symbol pairs will have a `Some(_)` entry, while
+    // non-unique pairs will have a `None` entry.
     let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =
         &mut FxHashMap::default();
 
@@ -3121,6 +3114,8 @@ pub fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> DefIdMap<Symbol> {
         }
     });
 
+    // Put the symbol from all the unique namespace+symbol pairs into `map`.
+    let mut map: DefIdMap<Symbol> = Default::default();
     for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() {
         use std::collections::hash_map::Entry::{Occupied, Vacant};
 

compiler/rustc_mir_build/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 either = "1"
+itertools = "0.11"
 rustc_apfloat = "0.2.0"
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }