Auto merge of rust-lang#125956 - Nilstrieb:rollup-rzr7co8, r=Nilstrieb

Rollup of 9 pull requests

Successful merges:

 - rust-lang#122804 (Item bounds can reference self projections and still be object safe)
 - rust-lang#124486 (Add tracking issue and unstable book page for `"vectorcall"` ABI)
 - rust-lang#125504 (Change pedantically incorrect OnceCell/OnceLock wording)
 - rust-lang#125608 (Avoid follow-up errors if the number of generic parameters already doesn't match)
 - rust-lang#125690 (ARM Target Docs Update)
 - rust-lang#125750 (Align `Term` methods with `GenericArg` methods, add `Term::expect_*`)
 - rust-lang#125818 (Handle no values cfgs with `--print=check-cfg`)
 - rust-lang#125909 (rustdoc: add a regression test for a former blanket impl synthesis ICE)
 - rust-lang#125919 (Remove stray "this")

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

Author: bors

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -263,7 +263,7 @@ fn push_debuginfo_type_name<'tcx>(
                         let ExistentialProjection { def_id: item_def_id, term, .. } =
                             tcx.instantiate_bound_regions_with_erased(bound);
                         // FIXME(associated_const_equality): allow for consts here
-                        (item_def_id, term.ty().unwrap())
+                        (item_def_id, term.expect_type())
                     })
                     .collect();
 

compiler/rustc_driver_impl/src/lib.rs

@@ -814,13 +814,17 @@ fn print_crate_info(
                     match expected_values {
                         ExpectedValues::Any => check_cfgs.push(format!("{name}=any()")),
                         ExpectedValues::Some(values) => {
-                            check_cfgs.extend(values.iter().map(|value| {
-                                if let Some(value) = value {
-                                    format!("{name}=\"{value}\"")
-                                } else {
-                                    name.to_string()
-                                }
-                            }))
+                            if !values.is_empty() {
+                                check_cfgs.extend(values.iter().map(|value| {
+                                    if let Some(value) = value {
+                                        format!("{name}=\"{value}\"")
+                                    } else {
+                                        name.to_string()
+                                    }
+                                }))
+                            } else {
+                                check_cfgs.push(format!("{name}="))
+                            }
                         }
                     }
                 }

compiler/rustc_feature/src/unstable.rs

@@ -177,8 +177,6 @@ declare_features! (
 
     /// Allows using the `unadjusted` ABI; perma-unstable.
     (internal, abi_unadjusted, "1.16.0", None),
-    /// Allows using the `vectorcall` ABI.
-    (unstable, abi_vectorcall, "1.7.0", None),
     /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`.
     (internal, allocator_internals, "1.20.0", None),
     /// Allows using `#[allow_internal_unsafe]`. This is an
@@ -243,6 +241,8 @@ declare_features! (
     // feature-group-start: internal feature gates
     // -------------------------------------------------------------------------
 
+    /// Allows using the `vectorcall` ABI.
+    (unstable, abi_vectorcall, "1.7.0", Some(124485)),
     /// Allows features specific to auto traits.
     /// Renamed from `optin_builtin_traits`.
     (unstable, auto_traits, "1.50.0", Some(13231)),

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -2281,7 +2281,7 @@ fn try_report_async_mismatch<'tcx>(
             && let Some(proj) = proj.no_bound_vars()
             && infcx.can_eq(
                 error.root_obligation.param_env,
-                proj.term.ty().unwrap(),
+                proj.term.expect_type(),
                 impl_sig.output(),
             )
         {

compiler/rustc_hir_analysis/src/check/compare_impl_item/refine.rs

@@ -267,7 +267,7 @@ fn report_mismatched_rpitit_signature<'tcx>(
             .explicit_item_bounds(future_ty.def_id)
             .iter_instantiated_copied(tcx, future_ty.args)
             .find_map(|(clause, _)| match clause.kind().no_bound_vars()? {
-                ty::ClauseKind::Projection(proj) => proj.term.ty(),
+                ty::ClauseKind::Projection(proj) => proj.term.as_type(),
                 _ => None,
             })
         else {

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -441,7 +441,9 @@ fn fn_sig_suggestion<'tcx>(
         output = if let ty::Alias(_, alias_ty) = *output.kind() {
             tcx.explicit_item_super_predicates(alias_ty.def_id)
                 .iter_instantiated_copied(tcx, alias_ty.args)
-                .find_map(|(bound, _)| bound.as_projection_clause()?.no_bound_vars()?.term.ty())
+                .find_map(|(bound, _)| {
+                    bound.as_projection_clause()?.no_bound_vars()?.term.as_type()
+                })
                 .unwrap_or_else(|| {
                     span_bug!(
                         ident.span,

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -702,7 +702,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     pub(crate) fn complain_about_missing_assoc_tys(
         &self,
         associated_types: FxIndexMap<Span, FxIndexSet<DefId>>,
-        potential_assoc_types: Vec<Span>,
+        potential_assoc_types: Vec<usize>,
         trait_bounds: &[hir::PolyTraitRef<'_>],
     ) {
         if associated_types.values().all(|v| v.is_empty()) {

compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs

@@ -214,10 +214,11 @@ pub fn lower_generic_args<'tcx: 'a, 'a>(
             if let Some(&param) = params.peek() {
                 if param.index == 0 {
                     if let GenericParamDefKind::Type { .. } = param.kind {
+                        assert_eq!(&args[..], &[]);
                         args.push(
                             self_ty
                                 .map(|ty| ty.into())
-                                .unwrap_or_else(|| ctx.inferred_kind(None, param, true)),
+                                .unwrap_or_else(|| ctx.inferred_kind(&args, param, true)),
                         );
                         params.next();
                     }
@@ -267,7 +268,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>(
                             // Since this is a const impl, we need to insert a host arg at the end of
                             // `PartialEq`'s generics, but this errors since `Rhs` isn't specified.
                             // To work around this, we infer all arguments until we reach the host param.
-                            args.push(ctx.inferred_kind(Some(&args), param, infer_args));
+                            args.push(ctx.inferred_kind(&args, param, infer_args));
                             params.next();
                         }
                         (GenericArg::Lifetime(_), GenericParamDefKind::Lifetime, _)
@@ -281,7 +282,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>(
                             GenericParamDefKind::Const { .. },
                             _,
                         ) => {
-                            args.push(ctx.provided_kind(param, arg));
+                            args.push(ctx.provided_kind(&args, param, arg));
                             args_iter.next();
                             params.next();
                         }
@@ -292,7 +293,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>(
                         ) => {
                             // We expected a lifetime argument, but got a type or const
                             // argument. That means we're inferring the lifetimes.
-                            args.push(ctx.inferred_kind(None, param, infer_args));
+                            args.push(ctx.inferred_kind(&args, param, infer_args));
                             force_infer_lt = Some((arg, param));
                             params.next();
                         }
@@ -388,7 +389,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>(
                 (None, Some(&param)) => {
                     // If there are fewer arguments than parameters, it means
                     // we're inferring the remaining arguments.
-                    args.push(ctx.inferred_kind(Some(&args), param, infer_args));
+                    args.push(ctx.inferred_kind(&args, param, infer_args));
                     params.next();
                 }
 
@@ -474,16 +475,9 @@ pub(crate) fn check_generic_arg_count(
             return Ok(());
         }
 
-        if provided_args > max_expected_args {
-            invalid_args.extend(
-                gen_args.args[max_expected_args..provided_args].iter().map(|arg| arg.span()),
-            );
-        };
+        invalid_args.extend(min_expected_args..provided_args);
 
         let gen_args_info = if provided_args > min_expected_args {
-            invalid_args.extend(
-                gen_args.args[min_expected_args..provided_args].iter().map(|arg| arg.span()),
-            );
             let num_redundant_args = provided_args - min_expected_args;
             GenericArgsInfo::ExcessLifetimes { num_redundant_args }
         } else {
@@ -538,11 +532,7 @@ pub(crate) fn check_generic_arg_count(
         let num_default_params = expected_max - expected_min;
 
         let gen_args_info = if provided > expected_max {
-            invalid_args.extend(
-                gen_args.args[args_offset + expected_max..args_offset + provided]
-                    .iter()
-                    .map(|arg| arg.span()),
-            );
+            invalid_args.extend((expected_max..provided).map(|i| i + args_offset));
             let num_redundant_args = provided - expected_max;
 
             // Provide extra note if synthetic arguments like `impl Trait` are specified.
@@ -610,7 +600,7 @@ pub(crate) fn check_generic_arg_count(
         explicit_late_bound,
         correct: lifetimes_correct
             .and(args_correct)
-            .map_err(|reported| GenericArgCountMismatch { reported: Some(reported), invalid_args }),
+            .map_err(|reported| GenericArgCountMismatch { reported, invalid_args }),
     }
 }
 

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -215,12 +215,11 @@ pub(crate) enum GenericArgPosition {
 
 /// A marker denoting that the generic arguments that were
 /// provided did not match the respective generic parameters.
-#[derive(Clone, Default, Debug)]
+#[derive(Clone, Debug)]
 pub struct GenericArgCountMismatch {
-    /// Indicates whether a fatal error was reported (`Some`), or just a lint (`None`).
-    pub reported: Option<ErrorGuaranteed>,
-    /// A list of spans of arguments provided that were not valid.
-    pub invalid_args: Vec<Span>,
+    pub reported: ErrorGuaranteed,
+    /// A list of indices of arguments provided that were not valid.
+    pub invalid_args: Vec<usize>,
 }
 
 /// Decorates the result of a generic argument count mismatch
@@ -240,13 +239,14 @@ pub trait GenericArgsLowerer<'a, 'tcx> {
 
     fn provided_kind(
         &mut self,
+        preceding_args: &[ty::GenericArg<'tcx>],
         param: &ty::GenericParamDef,
         arg: &GenericArg<'tcx>,
     ) -> ty::GenericArg<'tcx>;
 
     fn inferred_kind(
         &mut self,
-        args: Option<&[ty::GenericArg<'tcx>]>,
+        preceding_args: &[ty::GenericArg<'tcx>],
         param: &ty::GenericParamDef,
         infer_args: bool,
     ) -> ty::GenericArg<'tcx>;
@@ -404,10 +404,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             self_ty.is_some(),
         );
 
-        if let Err(err) = &arg_count.correct
-            && let Some(reported) = err.reported
-        {
-            self.set_tainted_by_errors(reported);
+        if let Err(err) = &arg_count.correct {
+            self.set_tainted_by_errors(err.reported);
         }
 
         // Skip processing if type has no generic parameters.
@@ -425,6 +423,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             span: Span,
             inferred_params: Vec<Span>,
             infer_args: bool,
+            incorrect_args: &'a Result<(), GenericArgCountMismatch>,
         }
 
         impl<'a, 'tcx> GenericArgsLowerer<'a, 'tcx> for GenericArgsCtxt<'a, 'tcx> {
@@ -439,11 +438,18 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
             fn provided_kind(
                 &mut self,
+                preceding_args: &[ty::GenericArg<'tcx>],
                 param: &ty::GenericParamDef,
                 arg: &GenericArg<'tcx>,
             ) -> ty::GenericArg<'tcx> {
                 let tcx = self.lowerer.tcx();
 
+                if let Err(incorrect) = self.incorrect_args {
+                    if incorrect.invalid_args.contains(&(param.index as usize)) {
+                        return param.to_error(tcx, preceding_args);
+                    }
+                }
+
                 let mut handle_ty_args = |has_default, ty: &hir::Ty<'tcx>| {
                     if has_default {
                         tcx.check_optional_stability(
@@ -506,11 +512,17 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
             fn inferred_kind(
                 &mut self,
-                args: Option<&[ty::GenericArg<'tcx>]>,
+                preceding_args: &[ty::GenericArg<'tcx>],
                 param: &ty::GenericParamDef,
                 infer_args: bool,
             ) -> ty::GenericArg<'tcx> {
                 let tcx = self.lowerer.tcx();
+
+                if let Err(incorrect) = self.incorrect_args {
+                    if incorrect.invalid_args.contains(&(param.index as usize)) {
+                        return param.to_error(tcx, preceding_args);
+                    }
+                }
                 match param.kind {
                     GenericParamDefKind::Lifetime => self
                         .lowerer
@@ -529,15 +541,19 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     GenericParamDefKind::Type { has_default, .. } => {
                         if !infer_args && has_default {
                             // No type parameter provided, but a default exists.
-                            let args = args.unwrap();
-                            if args.iter().any(|arg| match arg.unpack() {
-                                GenericArgKind::Type(ty) => ty.references_error(),
-                                _ => false,
-                            }) {
+                            if let Some(prev) =
+                                preceding_args.iter().find_map(|arg| match arg.unpack() {
+                                    GenericArgKind::Type(ty) => ty.error_reported().err(),
+                                    _ => None,
+                                })
+                            {
                                 // Avoid ICE #86756 when type error recovery goes awry.
-                                return Ty::new_misc_error(tcx).into();
+                                return Ty::new_error(tcx, prev).into();
                             }
-                            tcx.at(self.span).type_of(param.def_id).instantiate(tcx, args).into()
+                            tcx.at(self.span)
+                                .type_of(param.def_id)
+                                .instantiate(tcx, preceding_args)
+                                .into()
                         } else if infer_args {
                             self.lowerer.ty_infer(Some(param), self.span).into()
                         } else {
@@ -557,7 +573,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         // FIXME(effects) see if we should special case effect params here
                         if !infer_args && has_default {
                             tcx.const_param_default(param.def_id)
-                                .instantiate(tcx, args.unwrap())
+                                .instantiate(tcx, preceding_args)
                                 .into()
                         } else {
                             if infer_args {
@@ -571,6 +587,17 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 }
             }
         }
+        if let ty::BoundConstness::Const | ty::BoundConstness::ConstIfConst = constness
+            && generics.has_self
+            && !tcx.has_attr(def_id, sym::const_trait)
+        {
+            let reported = tcx.dcx().emit_err(crate::errors::ConstBoundForNonConstTrait {
+                span,
+                modifier: constness.as_str(),
+            });
+            self.set_tainted_by_errors(reported);
+            arg_count.correct = Err(GenericArgCountMismatch { reported, invalid_args: vec![] });
+        }
 
         let mut args_ctx = GenericArgsCtxt {
             lowerer: self,
@@ -579,19 +606,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             generic_args: segment.args(),
             inferred_params: vec![],
             infer_args: segment.infer_args,
+            incorrect_args: &arg_count.correct,
         };
-        if let ty::BoundConstness::Const | ty::BoundConstness::ConstIfConst = constness
-            && generics.has_self
-            && !tcx.has_attr(def_id, sym::const_trait)
-        {
-            let e = tcx.dcx().emit_err(crate::errors::ConstBoundForNonConstTrait {
-                span,
-                modifier: constness.as_str(),
-            });
-            self.set_tainted_by_errors(e);
-            arg_count.correct =
-                Err(GenericArgCountMismatch { reported: Some(e), invalid_args: vec![] });
-        }
         let args = lower_generic_args(
             tcx,
             def_id,

compiler/rustc_hir_analysis/src/impl_wf_check.rs

@@ -86,6 +86,8 @@ fn enforce_impl_params_are_constrained(
     let impl_predicates = tcx.predicates_of(impl_def_id);
     let impl_trait_ref = tcx.impl_trait_ref(impl_def_id).map(ty::EarlyBinder::instantiate_identity);
 
+    impl_trait_ref.error_reported()?;
+
     let mut input_parameters = cgp::parameters_for_impl(tcx, impl_self_ty, impl_trait_ref);
     cgp::identify_constrained_generic_params(
         tcx,