Auto merge of #118646 - matthiaskrgr:rollup-jnscl9z, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #117922 (Tweak unclosed generics errors)
 - #118471 (Fix typos in README.md)
 - #118594 (Remove mention of rust to make the error message generic.)
 - #118598 (Remove the `precise_pointer_size_matching` feature gate)
 - #118606 (Fix `x` not to quit after `x` prints `settings.json`)
 - #118608 (Use default params until effects in desugaring)
 - #118614 (Update books)
 - #118637 (rustc_symbol_mangling,rustc_interface,rustc_driver_impl: Enforce `rustc::potential_query_instability` lint)

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

compiler/rustc_driver_impl/src/lib.rs

@@ -13,7 +13,6 @@
 #![feature(let_chains)]
 #![feature(panic_update_hook)]
 #![recursion_limit = "256"]
-#![allow(rustc::potential_query_instability)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 

compiler/rustc_feature/src/removed.rs

@@ -158,6 +158,9 @@ declare_features! (
     /// Allows using `#[plugin_registrar]` on functions.
     (removed, plugin_registrar, "1.54.0", Some(29597), None,
      Some("plugins are no longer supported")),
+    /// Allows exhaustive integer pattern matching with `usize::MAX`/`isize::MIN`/`isize::MAX`.
+    (removed, precise_pointer_size_matching, "1.32.0", Some(56354), None,
+     Some("removed in favor of half-open ranges")),
     (removed, proc_macro_expr, "1.27.0", Some(54727), None,
      Some("subsumed by `#![feature(proc_macro_hygiene)]`")),
     (removed, proc_macro_gen, "1.27.0", Some(54727), None,

compiler/rustc_feature/src/unstable.rs

@@ -543,8 +543,6 @@ declare_features! (
     (unstable, offset_of_enum, "1.75.0", Some(106655), None),
     /// Allows using `#[optimize(X)]`.
     (unstable, optimize_attribute, "1.34.0", Some(54882), None),
-    /// Allows exhaustive integer pattern matching on `usize` and `isize`.
-    (unstable, precise_pointer_size_matching, "1.32.0", Some(56354), None),
     /// Allows macro attributes on expressions, statements and non-inline modules.
     (unstable, proc_macro_hygiene, "1.30.0", Some(54727), None),
     /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.

compiler/rustc_hir_analysis/src/astconv/generics.rs

@@ -243,6 +243,31 @@ pub fn create_args_for_parent_generic_args<'tcx, 'a>(
             match (args_iter.peek(), params.peek()) {
                 (Some(&arg), Some(&param)) => {
                     match (arg, &param.kind, arg_count.explicit_late_bound) {
+                        (
+                            GenericArg::Const(hir::ConstArg {
+                                is_desugared_from_effects: true,
+                                ..
+                            }),
+                            GenericParamDefKind::Const { is_host_effect: false, .. }
+                            | GenericParamDefKind::Type { .. }
+                            | GenericParamDefKind::Lifetime,
+                            _,
+                        ) => {
+                            // SPECIAL CASE FOR DESUGARED EFFECT PARAMS
+                            // This comes from the following example:
+                            //
+                            // ```
+                            // #[const_trait]
+                            // pub trait PartialEq<Rhs: ?Sized = Self> {}
+                            // impl const PartialEq for () {}
+                            // ```
+                            //
+                            // Since this is a const impl, we need to insert `<false>` 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));
+                            params.next();
+                        }
                         (GenericArg::Lifetime(_), GenericParamDefKind::Lifetime, _)
                         | (
                             GenericArg::Type(_) | GenericArg::Infer(_),

compiler/rustc_interface/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(let_chains)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
-#![allow(rustc::potential_query_instability)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 

compiler/rustc_interface/src/passes.rs

@@ -306,6 +306,8 @@ fn early_lint_checks(tcx: TyCtxt<'_>, (): ()) {
 
     // Gate identifiers containing invalid Unicode codepoints that were recovered during lexing.
     sess.parse_sess.bad_unicode_identifiers.with_lock(|identifiers| {
+        // We will soon sort, so the initial order does not matter.
+        #[allow(rustc::potential_query_instability)]
         let mut identifiers: Vec<_> = identifiers.drain().collect();
         identifiers.sort_by_key(|&(key, _)| key);
         for (ident, mut spans) in identifiers.into_iter() {
@@ -431,6 +433,9 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P
             escape_dep_filename(&file.prefer_local().to_string())
         };
 
+        // The entries will be used to declare dependencies beween files in a
+        // Makefile-like output, so the iteration order does not matter.
+        #[allow(rustc::potential_query_instability)]
         let extra_tracked_files =
             file_depinfo.iter().map(|path_sym| normalize_path(PathBuf::from(path_sym.as_str())));
         files.extend(extra_tracked_files);
@@ -486,6 +491,8 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P
             // Emit special comments with information about accessed environment variables.
             let env_depinfo = sess.parse_sess.env_depinfo.borrow();
             if !env_depinfo.is_empty() {
+                // We will soon sort, so the initial order does not matter.
+                #[allow(rustc::potential_query_instability)]
                 let mut envs: Vec<_> = env_depinfo
                     .iter()
                     .map(|(k, v)| (escape_dep_env(*k), v.map(escape_dep_env)))

compiler/rustc_mir_build/src/thir/pattern/check_match.rs

@@ -867,12 +867,6 @@ fn report_non_exhaustive_match<'p, 'tcx>(
                              exhaustively",
                     ));
                 }
-                if cx.tcx.sess.is_nightly_build() {
-                    err.help(format!(
-                            "add `#![feature(precise_pointer_size_matching)]` to the crate attributes to \
-                             enable precise `{ty}` matching",
-                        ));
-                }
             } else if ty == cx.tcx.types.str_ {
                 err.note("`&str` cannot be matched exhaustively, so a wildcard `_` is necessary");
             } else if cx.is_foreign_non_exhaustive_enum(ty) {

compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs

@@ -326,8 +326,7 @@ impl IntRange {
     /// `NegInfinity..PosInfinity`. In other words, as far as `IntRange` is concerned, there are
     /// values before `isize::MIN` and after `usize::MAX`/`isize::MAX`.
     /// This is to avoid e.g. `0..(u32::MAX as usize)` from being exhaustive on one architecture and
-    /// not others. See discussions around the `precise_pointer_size_matching` feature for more
-    /// details.
+    /// not others. This was decided in <https://github.com/rust-lang/rfcs/pull/2591>.
     ///
     /// These infinities affect splitting subtly: it is possible to get `NegInfinity..0` and
     /// `usize::MAX+1..PosInfinity` in the output. Diagnostics must be careful to handle these
@@ -380,7 +379,7 @@ impl IntRange {
     /// Whether the range denotes the fictitious values before `isize::MIN` or after
     /// `usize::MAX`/`isize::MAX` (see doc of [`IntRange::split`] for why these exist).
     pub(crate) fn is_beyond_boundaries<'tcx>(&self, ty: Ty<'tcx>, tcx: TyCtxt<'tcx>) -> bool {
-        ty.is_ptr_sized_integral() && !tcx.features().precise_pointer_size_matching && {
+        ty.is_ptr_sized_integral() && {
             // The two invalid ranges are `NegInfinity..isize::MIN` (represented as
             // `NegInfinity..0`), and `{u,i}size::MAX+1..PosInfinity`. `to_diagnostic_pat_range_bdy`
             // converts `MAX+1` to `PosInfinity`, and we couldn't have `PosInfinity` in `self.lo`
@@ -941,11 +940,8 @@ impl ConstructorSet {
                 }
             }
             &ty::Int(ity) => {
-                let range = if ty.is_ptr_sized_integral()
-                    && !cx.tcx.features().precise_pointer_size_matching
-                {
-                    // The min/max values of `isize` are not allowed to be observed unless the
-                    // `precise_pointer_size_matching` feature is enabled.
+                let range = if ty.is_ptr_sized_integral() {
+                    // The min/max values of `isize` are not allowed to be observed.
                     IntRange { lo: NegInfinity, hi: PosInfinity }
                 } else {
                     let bits = Integer::from_int_ty(&cx.tcx, ity).size().bits() as u128;
@@ -956,11 +952,8 @@ impl ConstructorSet {
                 Self::Integers { range_1: range, range_2: None }
             }
             &ty::Uint(uty) => {
-                let range = if ty.is_ptr_sized_integral()
-                    && !cx.tcx.features().precise_pointer_size_matching
-                {
-                    // The max value of `usize` is not allowed to be observed unless the
-                    // `precise_pointer_size_matching` feature is enabled.
+                let range = if ty.is_ptr_sized_integral() {
+                    // The max value of `usize` is not allowed to be observed.
                     let lo = MaybeInfiniteInt::new_finite(cx.tcx, ty, 0);
                     IntRange { lo, hi: PosInfinity }
                 } else {

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -673,15 +673,6 @@ impl<'a> Parser<'a> {
             );
         }
 
-        // Add suggestion for a missing closing angle bracket if '>' is included in expected_tokens
-        // there are unclosed angle brackets
-        if self.unmatched_angle_bracket_count > 0
-            && self.token.kind == TokenKind::Eq
-            && expected.iter().any(|tok| matches!(tok, TokenType::Token(TokenKind::Gt)))
-        {
-            err.span_label(self.prev_token.span, "maybe try to close unmatched angle bracket");
-        }
-
         let sp = if self.token == token::Eof {
             // This is EOF; don't want to point at the following char, but rather the last token.
             self.prev_token.span
@@ -811,6 +802,7 @@ impl<'a> Parser<'a> {
         }
         err.emit();
     }
+
     fn check_too_many_raw_str_terminators(&mut self, err: &mut Diagnostic) -> bool {
         let sm = self.sess.source_map();
         match (&self.prev_token.kind, &self.token.kind) {
@@ -1986,6 +1978,39 @@ impl<'a> Parser<'a> {
         }
     }
 
+    /// When trying to close a generics list and encountering code like
+    /// ```text
+    /// impl<S: Into<std::borrow::Cow<'static, str>> From<S> for Canonical {}
+    ///                                          // ^ missing > here
+    /// ```
+    /// we provide a structured suggestion on the error from `expect_gt`.
+    pub(super) fn expect_gt_or_maybe_suggest_closing_generics(
+        &mut self,
+        params: &[ast::GenericParam],
+    ) -> PResult<'a, ()> {
+        let Err(mut err) = self.expect_gt() else {
+            return Ok(());
+        };
+        // Attempt to find places where a missing `>` might belong.
+        if let [.., ast::GenericParam { bounds, .. }] = params
+            && let Some(poly) = bounds
+                .iter()
+                .filter_map(|bound| match bound {
+                    ast::GenericBound::Trait(poly, _) => Some(poly),
+                    _ => None,
+                })
+                .last()
+        {
+            err.span_suggestion_verbose(
+                poly.span.shrink_to_hi(),
+                "you might have meant to end the type parameters here",
+                ">",
+                Applicability::MaybeIncorrect,
+            );
+        }
+        Err(err)
+    }
+
     pub(super) fn recover_seq_parse_error(
         &mut self,
         delim: Delimiter,

compiler/rustc_parse/src/parser/generics.rs

@@ -279,7 +279,7 @@ impl<'a> Parser<'a> {
         let span_lo = self.token.span;
         let (params, span) = if self.eat_lt() {
             let params = self.parse_generic_params()?;
-            self.expect_gt()?;
+            self.expect_gt_or_maybe_suggest_closing_generics(&params)?;
             (params, span_lo.to(self.prev_token.span))
         } else {
             (ThinVec::new(), self.prev_token.span.shrink_to_hi())

compiler/rustc_symbol_mangling/src/lib.rs

@@ -93,7 +93,6 @@
 #![allow(internal_features)]
 #![feature(never_type)]
 #![recursion_limit = "256"]
-#![allow(rustc::potential_query_instability)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]