Auto merge of rust-lang#112661 - matthiaskrgr:rollup-9u5i2zy, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#111212 (Add casting suggestion when assigning negative 2's complement bin or hex literal to a size compatible signed integer)
 - rust-lang#112304 (Add chapter in rustdoc book for re-exports and add a regression test for `#[doc(hidden)]` behaviour)
 - rust-lang#112486 (Fix suggestion for E0404 not dealing with multiple generics)
 - rust-lang#112562 (rustdoc-gui: allow running on Windows)
 - rust-lang#112621 (Mention `env!` in `option_env!`'s docs)
 - rust-lang#112634 (add InlineConst check)

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

Author: bors

compiler/rustc_ast_pretty/src/pprust/mod.rs

@@ -32,6 +32,10 @@ pub fn bounds_to_string(bounds: &[ast::GenericBound]) -> String {
     State::new().bounds_to_string(bounds)
 }
 
+pub fn where_bound_predicate_to_string(where_bound_predicate: &ast::WhereBoundPredicate) -> String {
+    State::new().where_bound_predicate_to_string(where_bound_predicate)
+}
+
 pub fn pat_to_string(pat: &ast::Pat) -> String {
     State::new().pat_to_string(pat)
 }

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -824,6 +824,13 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         Self::to_string(|s| s.print_type_bounds(bounds))
     }
 
+    fn where_bound_predicate_to_string(
+        &self,
+        where_bound_predicate: &ast::WhereBoundPredicate,
+    ) -> String {
+        Self::to_string(|s| s.print_where_bound_predicate(where_bound_predicate))
+    }
+
     fn pat_to_string(&self, pat: &ast::Pat) -> String {
         Self::to_string(|s| s.print_pat(pat))
     }

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -623,19 +623,8 @@ impl<'a> State<'a> {
 
     pub fn print_where_predicate(&mut self, predicate: &ast::WherePredicate) {
         match predicate {
-            ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
-                bound_generic_params,
-                bounded_ty,
-                bounds,
-                ..
-            }) => {
-                self.print_formal_generic_params(bound_generic_params);
-                self.print_type(bounded_ty);
-                self.word(":");
-                if !bounds.is_empty() {
-                    self.nbsp();
-                    self.print_type_bounds(bounds);
-                }
+            ast::WherePredicate::BoundPredicate(where_bound_predicate) => {
+                self.print_where_bound_predicate(where_bound_predicate);
             }
             ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
                 lifetime,
@@ -658,6 +647,19 @@ impl<'a> State<'a> {
         }
     }
 
+    pub fn print_where_bound_predicate(
+        &mut self,
+        where_bound_predicate: &ast::WhereBoundPredicate,
+    ) {
+        self.print_formal_generic_params(&where_bound_predicate.bound_generic_params);
+        self.print_type(&where_bound_predicate.bounded_ty);
+        self.word(":");
+        if !where_bound_predicate.bounds.is_empty() {
+            self.nbsp();
+            self.print_type_bounds(&where_bound_predicate.bounds);
+        }
+    }
+
     fn print_use_tree(&mut self, tree: &ast::UseTree) {
         match &tree.kind {
             ast::UseTreeKind::Simple(rename) => {

compiler/rustc_lint/messages.ftl

@@ -425,6 +425,7 @@ lint_overflowing_bin_hex = literal out of range for `{$ty}`
     .negative_becomes_note = and the value `-{$lit}` will become `{$actually}{$ty}`
     .positive_note = the literal `{$lit}` (decimal `{$dec}`) does not fit into the type `{$ty}` and will become `{$actually}{$ty}`
     .suggestion = consider using the type `{$suggestion_ty}` instead
+    .sign_bit_suggestion = to use as a negative number (decimal `{$negative_val}`), consider using the type `{$uint_ty}` for the literal and cast it to `{$int_ty}`
     .help = consider using the type `{$suggestion_ty}` instead
 
 lint_overflowing_int = literal out of range for `{$ty}`

compiler/rustc_lint/src/lints.rs

@@ -1342,6 +1342,8 @@ pub struct OverflowingBinHex<'a> {
     pub sign: OverflowingBinHexSign,
     #[subdiagnostic]
     pub sub: Option<OverflowingBinHexSub<'a>>,
+    #[subdiagnostic]
+    pub sign_bit_sub: Option<OverflowingBinHexSignBitSub<'a>>,
 }
 
 pub enum OverflowingBinHexSign {
@@ -1386,6 +1388,21 @@ pub enum OverflowingBinHexSub<'a> {
     Help { suggestion_ty: &'a str },
 }
 
+#[derive(Subdiagnostic)]
+#[suggestion(
+    lint_sign_bit_suggestion,
+    code = "{lit_no_suffix}{uint_ty} as {int_ty}",
+    applicability = "maybe-incorrect"
+)]
+pub struct OverflowingBinHexSignBitSub<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub lit_no_suffix: &'a str,
+    pub negative_val: String,
+    pub uint_ty: &'a str,
+    pub int_ty: &'a str,
+}
+
 #[derive(LintDiagnostic)]
 #[diag(lint_overflowing_int)]
 #[note]

compiler/rustc_lint/src/types.rs

@@ -3,9 +3,10 @@ use crate::{
     lints::{
         AtomicOrderingFence, AtomicOrderingLoad, AtomicOrderingStore, ImproperCTypes,
         InvalidAtomicOrderingDiag, InvalidNanComparisons, InvalidNanComparisonsSuggestion,
-        OnlyCastu8ToChar, OverflowingBinHex, OverflowingBinHexSign, OverflowingBinHexSub,
-        OverflowingInt, OverflowingIntHelp, OverflowingLiteral, OverflowingUInt,
-        RangeEndpointOutOfRange, UnusedComparisons, UseInclusiveRange, VariantSizeDifferencesDiag,
+        OnlyCastu8ToChar, OverflowingBinHex, OverflowingBinHexSign, OverflowingBinHexSignBitSub,
+        OverflowingBinHexSub, OverflowingInt, OverflowingIntHelp, OverflowingLiteral,
+        OverflowingUInt, RangeEndpointOutOfRange, UnusedComparisons, UseInclusiveRange,
+        VariantSizeDifferencesDiag,
     },
 };
 use crate::{LateContext, LateLintPass, LintContext};
@@ -297,10 +298,50 @@ fn report_bin_hex_error(
             }
         },
     );
+    let sign_bit_sub = (!negative)
+        .then(|| {
+            let ty::Int(int_ty) = cx.typeck_results().node_type(expr.hir_id).kind() else {
+                return None;
+            };
+
+            let Some(bit_width) = int_ty.bit_width() else {
+                return None; // isize case
+            };
+
+            // Skip if sign bit is not set
+            if (val & (1 << (bit_width - 1))) == 0 {
+                return None;
+            }
+
+            let lit_no_suffix =
+                if let Some(pos) = repr_str.chars().position(|c| c == 'i' || c == 'u') {
+                    repr_str.split_at(pos).0
+                } else {
+                    &repr_str
+                };
+
+            Some(OverflowingBinHexSignBitSub {
+                span: expr.span,
+                lit_no_suffix,
+                negative_val: actually.clone(),
+                int_ty: int_ty.name_str(),
+                uint_ty: int_ty.to_unsigned().name_str(),
+            })
+        })
+        .flatten();
+
     cx.emit_spanned_lint(
         OVERFLOWING_LITERALS,
         expr.span,
-        OverflowingBinHex { ty: t, lit: repr_str.clone(), dec: val, actually, sign, sub },
+        OverflowingBinHex {
+            ty: t,
+            lit: repr_str.clone(),
+            dec: val,
+            actually,
+            sign,
+            sub,
+            sign_bit_sub,
+        },
     )
 }
 

compiler/rustc_middle/src/mir/interpret/queries.rs

@@ -95,7 +95,10 @@ impl<'tcx> TyCtxt<'tcx> {
                     // used generic parameters is a bug of evaluation, so checking for it
                     // here does feel somewhat sensible.
                     if !self.features().generic_const_exprs && ct.substs.has_non_region_param() {
-                        assert!(matches!(self.def_kind(ct.def), DefKind::AnonConst));
+                        assert!(matches!(
+                            self.def_kind(ct.def),
+                            DefKind::InlineConst | DefKind::AnonConst
+                        ));
                         let mir_body = self.mir_for_ctfe(ct.def);
                         if mir_body.is_polymorphic {
                             let Some(local_def_id) = ct.def.as_local() else { return };

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -10,7 +10,7 @@ use rustc_ast::{
     self as ast, AssocItemKind, Expr, ExprKind, GenericParam, GenericParamKind, Item, ItemKind,
     MethodCall, NodeId, Path, Ty, TyKind, DUMMY_NODE_ID,
 };
-use rustc_ast_pretty::pprust::path_segment_to_string;
+use rustc_ast_pretty::pprust::where_bound_predicate_to_string;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{
     pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed,
@@ -1050,7 +1050,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             };
 
         // Confirm that the target is an associated type.
-        let (ty, position, path) = if let ast::TyKind::Path(Some(qself), path) = &bounded_ty.kind {
+        let (ty, _, path) = if let ast::TyKind::Path(Some(qself), path) = &bounded_ty.kind {
             // use this to verify that ident is a type param.
             let Some(partial_res) = self.r.partial_res_map.get(&bounded_ty.id) else {
                 return false;
@@ -1079,37 +1079,19 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 return false;
             }
             if let (
-                [ast::PathSegment { ident: constrain_ident, args: None, .. }],
+                [ast::PathSegment { args: None, .. }],
                 [ast::GenericBound::Trait(poly_trait_ref, ast::TraitBoundModifier::None)],
             ) = (&type_param_path.segments[..], &bounds[..])
             {
                 if let [ast::PathSegment { ident, args: None, .. }] =
                     &poly_trait_ref.trait_ref.path.segments[..]
                 {
                     if ident.span == span {
+                        let Some(new_where_bound_predicate) = mk_where_bound_predicate(path, poly_trait_ref, ty) else { return false; };
                         err.span_suggestion_verbose(
                             *where_span,
                             format!("constrain the associated type to `{}`", ident),
-                            format!(
-                                "{}: {}<{} = {}>",
-                                self.r
-                                    .tcx
-                                    .sess
-                                    .source_map()
-                                    .span_to_snippet(ty.span) // Account for `<&'a T as Foo>::Bar`.
-                                    .unwrap_or_else(|_| constrain_ident.to_string()),
-                                path.segments[..position]
-                                    .iter()
-                                    .map(|segment| path_segment_to_string(segment))
-                                    .collect::<Vec<_>>()
-                                    .join("::"),
-                                path.segments[position..]
-                                    .iter()
-                                    .map(|segment| path_segment_to_string(segment))
-                                    .collect::<Vec<_>>()
-                                    .join("::"),
-                                ident,
-                            ),
+                            where_bound_predicate_to_string(&new_where_bound_predicate),
                             Applicability::MaybeIncorrect,
                         );
                     }
@@ -2605,6 +2587,70 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
     }
 }
 
+fn mk_where_bound_predicate(
+    path: &Path,
+    poly_trait_ref: &ast::PolyTraitRef,
+    ty: &ast::Ty,
+) -> Option<ast::WhereBoundPredicate> {
+    use rustc_span::DUMMY_SP;
+    let modified_segments = {
+        let mut segments = path.segments.clone();
+        let [preceding @ .., second_last, last] = segments.as_mut_slice() else { return None; };
+        let mut segments = ThinVec::from(preceding);
+
+        let added_constraint = ast::AngleBracketedArg::Constraint(ast::AssocConstraint {
+            id: DUMMY_NODE_ID,
+            ident: last.ident,
+            gen_args: None,
+            kind: ast::AssocConstraintKind::Equality {
+                term: ast::Term::Ty(ast::ptr::P(ast::Ty {
+                    kind: ast::TyKind::Path(None, poly_trait_ref.trait_ref.path.clone()),
+                    id: DUMMY_NODE_ID,
+                    span: DUMMY_SP,
+                    tokens: None,
+                })),
+            },
+            span: DUMMY_SP,
+        });
+
+        match second_last.args.as_deref_mut() {
+            Some(ast::GenericArgs::AngleBracketed(ast::AngleBracketedArgs { args, .. })) => {
+                args.push(added_constraint);
+            }
+            Some(_) => return None,
+            None => {
+                second_last.args =
+                    Some(ast::ptr::P(ast::GenericArgs::AngleBracketed(ast::AngleBracketedArgs {
+                        args: ThinVec::from([added_constraint]),
+                        span: DUMMY_SP,
+                    })));
+            }
+        }
+
+        segments.push(second_last.clone());
+        segments
+    };
+
+    let new_where_bound_predicate = ast::WhereBoundPredicate {
+        span: DUMMY_SP,
+        bound_generic_params: ThinVec::new(),
+        bounded_ty: ast::ptr::P(ty.clone()),
+        bounds: vec![ast::GenericBound::Trait(
+            ast::PolyTraitRef {
+                bound_generic_params: ThinVec::new(),
+                trait_ref: ast::TraitRef {
+                    path: ast::Path { segments: modified_segments, span: DUMMY_SP, tokens: None },
+                    ref_id: DUMMY_NODE_ID,
+                },
+                span: DUMMY_SP,
+            },
+            ast::TraitBoundModifier::None,
+        )],
+    };
+
+    Some(new_where_bound_predicate)
+}
+
 /// Report lifetime/lifetime shadowing as an error.
 pub(super) fn signal_lifetime_shadowing(sess: &Session, orig: Ident, shadower: Ident) {
     let mut err = struct_span_err!(

config.example.toml

@@ -250,6 +250,13 @@ changelog-seen = 2
 # target when running tests, otherwise this can be omitted.
 #nodejs = "node"
 
+# The npm executable to use. Note that this is used for rustdoc-gui tests,
+# otherwise this can be omitted.
+#
+# Under Windows this should be `npm.cmd` or path to it (verified on nodejs v18.06), or
+# error will be emitted.
+#npm = "npm"
+
 # Python interpreter to use for various tasks throughout the build, notably
 # rustdoc tests, the lldb python interpreter, and some dist bits and pieces.
 #

library/core/src/macros/mod.rs

@@ -960,6 +960,8 @@ pub(crate) mod builtin {
     ///
     /// A compile time error is never emitted when using this macro regardless
     /// of whether the environment variable is present or not.
+    /// To emit a compile error if the environment variable is not present,
+    /// use the [`env!`] macro instead.
     ///
     /// # Examples
     ///