Rollup of 10 pull requests

Cargo.lock

@@ -2955,9 +2955,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.2.5"
+version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94341e4e44e24f6b591b59e47a8a027df12e008d73fd5672dbea9cc22f4507d9"
+checksum = "8383f39639269cde97d255a32bdb68c047337295414940c68bdd30c2e13203ff"
 dependencies = [
  "bitflags",
 ]

RELEASES.md

@@ -1,3 +1,145 @@
+Version 1.55.0 (2021-09-09)
+============================
+
+Language
+--------
+- [You can now write open "from" range patterns (`X..`), which will start at `X` and
+  will end at the maximum value of the integer.][83918]
+- [You can now explicitly import the prelude of different editions
+  through `std::prelude` (e.g. `use std::prelude::rust_2021::*;`).][86294]
+
+Compiler
+--------
+- [Added tier 3\* support for `powerpc-unknown-freebsd`.][87370]
+- [Added tier 3 support for `powerpc64le-unknown-freebsd`.][83572]
+
+\* Refer to Rust's [platform support page][platform-support-doc] for more
+   information on Rust's tiered platform support.
+
+Libraries
+---------
+
+- [Updated std's float parsing to use the Eisel-Lemire algorithm.][86761]
+  These improvements should in general provide faster string parsing of floats,
+  no longer reject certain valid floating point values, and reduce
+  the produced code size for non-stripped artifacts.
+- [`string::Drain` now implements `AsRef<str>` and `AsRef<[u8]>`.][86858]
+- [`collections::{BinaryHeap, BTreeSet, HashSet, LinkedList, VecDeque}` now
+  implement `From<[T; N]>`.][84111]
+- [`collections::{BTreeMap, HashMap}` now implement `From<[(K, V); N]>`.][84111]
+  This allows you to write the following;
+  ```rust
+  let highscores = std::collections::HashMap::from([
+      ("Alice", 9000u32),
+      ("Bob", 7250),
+      ("Charlie", 5500),
+  ]);
+  ```
+
+Stabilised APIs
+---------------
+
+- [`Bound::cloned`]
+- [`Drain::as_str`]
+- [`IntoInnerError::into_error`]
+- [`IntoInnerError::into_parts`]
+- [`MaybeUninit::assume_init_mut`]
+- [`MaybeUninit::assume_init_ref`]
+- [`MaybeUninit::write`]
+- [`array::map`]
+- [`ops::ControlFlow`]
+- [`x86::_bittest`]
+- [`x86::_bittestandcomplement`]
+- [`x86::_bittestandreset`]
+- [`x86::_bittestandset`]
+- [`x86_64::_bittest64`]
+- [`x86_64::_bittestandcomplement64`]
+- [`x86_64::_bittestandreset64`]
+- [`x86_64::_bittestandset64`]
+
+The following previously stable functions are now `const`.
+
+- [`str::from_utf8_unchecked`]
+- [`mem::transmute`]
+
+
+Cargo
+-----
+- [Cargo will now deduplicate compiler diagnostics to the terminal when invoking
+  rustc in parallel such as when using `cargo test`.][cargo/9675]
+- [The package definition in `cargo metadata` now includes the `"default_run"`
+  field from the manifest.][cargo/9550]
+- [Added `cargo d` as an alias for `cargo doc`.][cargo/9680]
+
+Rustdoc
+-------
+- [Added "Go to item on exact match" search option.][85876]
+- [The "Implementors" section on traits no longer shows redundant
+  method definitions.][85970]
+- [Trait implementations are toggled open by default.][86260] This should make the
+  implementations more searchable by tools like `CTRL+F` in your browser.
+- [Intra-doc links should now correctly resolve associated items (e.g. methods)
+  through type aliases.][86334]
+- [Traits which are marked with `#[doc(hidden)]` will no longer appear in the
+  "Trait Implementations" section.][86513]
+
+
+Compatibility Notes
+-------------------
+- [std functions that return an `io::Error` will no longer use the
+  `ErrorKind::Other` variant.][85746] This is to better reflect that these
+  kinds of errors could be categorised [into newer more specific `ErrorKind`
+  variants][79965], and that they do not represent a user error.
+- [Using environment variable names with `process::Command` on Windows now
+  behaves as expected.][85270] Previously using envionment variables with
+  `Command` would cause them to be ASCII-uppercased.
+- [Rustdoc will now warn on using rustdoc lints that aren't prefixed
+  with `rustdoc::`][86849]
+
+[86849]: https://github.com/rust-lang/rust/pull/86849
+[86513]: https://github.com/rust-lang/rust/pull/86513
+[86334]: https://github.com/rust-lang/rust/pull/86334
+[86260]: https://github.com/rust-lang/rust/pull/86260
+[85970]: https://github.com/rust-lang/rust/pull/85970
+[85876]: https://github.com/rust-lang/rust/pull/85876
+[83572]: https://github.com/rust-lang/rust/pull/83572
+[86294]: https://github.com/rust-lang/rust/pull/86294
+[86858]: https://github.com/rust-lang/rust/pull/86858
+[86761]: https://github.com/rust-lang/rust/pull/86761
+[85769]: https://github.com/rust-lang/rust/pull/85769
+[85746]: https://github.com/rust-lang/rust/pull/85746
+[85305]: https://github.com/rust-lang/rust/pull/85305
+[85270]: https://github.com/rust-lang/rust/pull/85270
+[84111]: https://github.com/rust-lang/rust/pull/84111
+[83918]: https://github.com/rust-lang/rust/pull/83918
+[79965]: https://github.com/rust-lang/rust/pull/79965
+[87370]: https://github.com/rust-lang/rust/pull/87370
+[87298]: https://github.com/rust-lang/rust/pull/87298
+[cargo/9675]: https://github.com/rust-lang/cargo/pull/9675
+[cargo/9550]: https://github.com/rust-lang/cargo/pull/9550
+[cargo/9680]: https://github.com/rust-lang/cargo/pull/9680
+[`array::map`]: https://doc.rust-lang.org/stable/std/primitive.array.html#method.map
+[`Bound::cloned`]: https://doc.rust-lang.org/stable/std/ops/enum.Bound.html#method.cloned
+[`Drain::as_str`]: https://doc.rust-lang.org/stable/std/string/struct.Drain.html#method.as_str
+[`IntoInnerError::into_error`]: https://doc.rust-lang.org/stable/std/io/struct.IntoInnerError.html#method.into_error
+[`IntoInnerError::into_parts`]: https://doc.rust-lang.org/stable/std/io/struct.IntoInnerError.html#method.into_parts
+[`MaybeUninit::assume_init_mut`]: https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.assume_init_mut
+[`MaybeUninit::assume_init_ref`]: https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.assume_init_ref
+[`MaybeUninit::write`]: https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.write
+[`Seek::rewind`]: https://doc.rust-lang.org/stable/std/io/trait.Seek.html#method.rewind
+[`mem::transmute`]: https://doc.rust-lang.org/stable/std/mem/fn.transmute.html
+[`ops::ControlFlow`]: https://doc.rust-lang.org/stable/std/ops/enum.ControlFlow.html
+[`str::from_utf8_unchecked`]: https://doc.rust-lang.org/stable/std/str/fn.from_utf8_unchecked.html
+[`x86::_bittest`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittest.html
+[`x86::_bittestandcomplement`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittestandcomplement.html
+[`x86::_bittestandreset`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittestandreset.html
+[`x86::_bittestandset`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittestandset.html
+[`x86_64::_bittest64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittest64.html
+[`x86_64::_bittestandcomplement64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittestandcomplement64.html
+[`x86_64::_bittestandreset64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittestandreset64.html
+[`x86_64::_bittestandset64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittestandset64.html
+
+
 Version 1.54.0 (2021-07-29)
 ============================
 

compiler/rustc_infer/src/traits/engine.rs

@@ -63,7 +63,7 @@ pub trait TraitEngine<'tcx>: 'tcx {
         infcx: &InferCtxt<'_, 'tcx>,
     ) -> Result<(), Vec<FulfillmentError<'tcx>>>;
 
-    // FIXME this should not provide a default body for chalk as chalk should be updated
+    // FIXME(fee1-dead) this should not provide a default body for chalk as chalk should be updated
     fn select_with_constness_where_possible(
         &mut self,
         infcx: &InferCtxt<'_, 'tcx>,

compiler/rustc_lint/src/non_fmt_panic.rs

@@ -101,7 +101,7 @@ fn check_panic<'tcx>(cx: &LateContext<'tcx>, f: &'tcx hir::Expr<'tcx>, arg: &'tc
         let mut l = lint.build("panic message is not a string literal");
         l.note("this usage of panic!() is deprecated; it will be a hard error in Rust 2021");
         l.note("for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>");
-        if !span.contains(arg_span) {
+        if !is_arg_inside_call(arg_span, span) {
             // No clue where this argument is coming from.
             l.emit();
             return;
@@ -204,7 +204,7 @@ fn check_panic_str<'tcx>(
                 _ => "panic message contains unused formatting placeholders",
             });
             l.note("this message is not used as a format string when given without arguments, but will be in Rust 2021");
-            if span.contains(arg.span) {
+            if is_arg_inside_call(arg.span, span) {
                 l.span_suggestion(
                     arg.span.shrink_to_hi(),
                     &format!("add the missing argument{}", pluralize!(n_arguments)),
@@ -235,7 +235,7 @@ fn check_panic_str<'tcx>(
         cx.struct_span_lint(NON_FMT_PANICS, brace_spans.unwrap_or_else(|| vec![span]), |lint| {
             let mut l = lint.build(msg);
             l.note("this message is not used as a format string, but will be in Rust 2021");
-            if span.contains(arg.span) {
+            if is_arg_inside_call(arg.span, span) {
                 l.span_suggestion(
                     arg.span.shrink_to_lo(),
                     "add a \"{}\" format string to use the message literally",
@@ -283,3 +283,11 @@ fn panic_call<'tcx>(cx: &LateContext<'tcx>, f: &'tcx hir::Expr<'tcx>) -> (Span,
         if let hygiene::ExpnKind::Macro(_, symbol) = expn.kind { symbol } else { sym::panic };
     (expn.call_site, panic_macro, macro_symbol.as_str())
 }
+
+fn is_arg_inside_call(arg: Span, call: Span) -> bool {
+    // We only add suggestions if the argument we're looking at appears inside the
+    // panic call in the source file, to avoid invalid suggestions when macros are involved.
+    // We specifically check for the spans to not be identical, as that happens sometimes when
+    // proc_macros lie about spans and apply the same span to all the tokens they produce.
+    call.contains(arg) && !call.source_equal(&arg)
+}

compiler/rustc_mir/src/transform/check_consts/mod.rs

@@ -9,7 +9,7 @@ use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::mir;
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_span::Symbol;
+use rustc_span::{sym, Symbol};
 
 pub use self::qualifs::Qualif;
 
@@ -104,6 +104,13 @@ pub fn rustc_allow_const_fn_unstable(
 pub fn is_const_stable_const_fn(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
     use attr::{ConstStability, Stability, StabilityLevel};
 
+    // A default body marked const is not const-stable because const
+    // trait fns currently cannot be const-stable. We shouldn't
+    // restrict default bodies to only call const-stable functions.
+    if tcx.has_attr(def_id, sym::default_method_body_is_const) {
+        return false;
+    }
+
     // Const-stability is only relevant for `const fn`.
     assert!(tcx.is_const_fn_raw(def_id));
 

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -316,7 +316,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         self.infcx.tcx
     }
 
-    /// returns `true` if the predicate is considered `const` to
+    /// Returns `true` if the predicate is considered `const` to
     /// this selection context.
     pub fn is_predicate_const(&self, pred: ty::Predicate<'_>) -> bool {
         match pred.kind().skip_binder() {

compiler/rustc_traits/src/type_op.rs

@@ -6,9 +6,7 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::TraitEngineExt as _;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::{GenericArg, Subst, UserSelfTy, UserSubsts};
-use rustc_middle::ty::{
-    self, FnSig, Lift, PolyFnSig, PredicateKind, Ty, TyCtxt, TypeFoldable, Variance,
-};
+use rustc_middle::ty::{self, FnSig, Lift, PolyFnSig, Ty, TyCtxt, TypeFoldable, Variance};
 use rustc_middle::ty::{ParamEnv, ParamEnvAnd, Predicate, ToPredicate};
 use rustc_span::DUMMY_SP;
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
@@ -87,16 +85,7 @@ impl AscribeUserTypeCx<'me, 'tcx> {
         Ok(())
     }
 
-    fn prove_predicate(&mut self, mut predicate: Predicate<'tcx>) {
-        if let PredicateKind::Trait(mut tr) = predicate.kind().skip_binder() {
-            if let hir::Constness::Const = tr.constness {
-                // FIXME check if we actually want to prove const predicates inside AscribeUserType
-                tr.constness = hir::Constness::NotConst;
-                predicate =
-                    predicate.kind().rebind(PredicateKind::Trait(tr)).to_predicate(self.tcx());
-            }
-        }
-
+    fn prove_predicate(&mut self, predicate: Predicate<'tcx>) {
         self.fulfill_cx.register_predicate_obligation(
             self.infcx,
             Obligation::new(ObligationCause::dummy(), self.param_env, predicate),

compiler/rustc_typeck/src/check/upvar.rs

@@ -47,7 +47,7 @@ use rustc_middle::ty::{
 };
 use rustc_session::lint;
 use rustc_span::sym;
-use rustc_span::{MultiSpan, Span, Symbol, DUMMY_SP};
+use rustc_span::{BytePos, MultiSpan, Pos, Span, Symbol, DUMMY_SP};
 use rustc_trait_selection::infer::InferCtxtExt;
 
 use rustc_data_structures::stable_map::FxHashMap;
@@ -645,6 +645,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                     diagnostics_builder.note("for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>");
 
+                    let diagnostic_msg = format!(
+                        "add a dummy let to cause {} to be fully captured",
+                        migrated_variables_concat
+                    );
+
                     let mut closure_body_span = self.tcx.hir().span(body_id.hir_id);
 
                     // If the body was entirely expanded from a macro
@@ -655,43 +660,54 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         closure_body_span = closure_body_span.parent().unwrap_or(DUMMY_SP);
                     }
 
-                    let (span, sugg, app) =
-                        match self.tcx.sess.source_map().span_to_snippet(closure_body_span) {
-                            Ok(s) => {
-                                let trimmed = s.trim_start();
-                                let mut lines = trimmed.lines();
-                                let line1 = lines.next().unwrap_or_default();
-
-                                // If the closure contains a block then replace the opening brace
-                                // with "{ let _ = (..); "
-                                let sugg = if line1.trim_end() == "{" {
-                                    // This is a multi-line closure with just a `{` on the first line,
-                                    // so we put the `let` on its own line.
-                                    // We take the indentation from the next non-empty line.
-                                    let line2 = lines.filter(|line| !line.is_empty()).next().unwrap_or_default();
-                                    let indent = line2.split_once(|c: char| !c.is_whitespace()).unwrap_or_default().0;
-                                    format!("{{\n{}{};{}", indent, migration_string, &trimmed[line1.len()..])
-                                } else if line1.starts_with('{') {
-                                    format!("{{ {}; {}", migration_string, &trimmed[1..].trim_start())
-                                } else {
-                                    format!("{{ {}; {} }}", migration_string, s)
-                                };
-                                (closure_body_span, sugg, Applicability::MachineApplicable)
-                            }
-                            Err(_) => (closure_span, migration_string.clone(), Applicability::HasPlaceholders),
-                        };
-
-                    let diagnostic_msg = format!(
-                        "add a dummy let to cause {} to be fully captured",
-                        migrated_variables_concat
-                    );
+                    if let Ok(s) = self.tcx.sess.source_map().span_to_snippet(closure_body_span) {
+                        let mut lines = s.lines();
+                        let line1 = lines.next().unwrap_or_default();
+
+                        if line1.trim_end() == "{" {
+                            // This is a multi-line closure with just a `{` on the first line,
+                            // so we put the `let` on its own line.
+                            // We take the indentation from the next non-empty line.
+                            let line2 = lines.filter(|line| !line.is_empty()).next().unwrap_or_default();
+                            let indent = line2.split_once(|c: char| !c.is_whitespace()).unwrap_or_default().0;
+                            diagnostics_builder.span_suggestion(
+                                closure_body_span.with_lo(closure_body_span.lo() + BytePos::from_usize(line1.len())).shrink_to_lo(),
+                                &diagnostic_msg,
+                                format!("\n{}{};", indent, migration_string),
+                                Applicability::MachineApplicable,
+                            );
+                        } else if line1.starts_with('{') {
+                            // This is a closure with its body wrapped in
+                            // braces, but with more than just the opening
+                            // brace on the first line. We put the `let`
+                            // directly after the `{`.
+                            diagnostics_builder.span_suggestion(
+                                closure_body_span.with_lo(closure_body_span.lo() + BytePos(1)).shrink_to_lo(),
+                                &diagnostic_msg,
+                                format!(" {};", migration_string),
+                                Applicability::MachineApplicable,
+                            );
+                        } else {
+                            // This is a closure without braces around the body.
+                            // We add braces to add the `let` before the body.
+                            diagnostics_builder.multipart_suggestion(
+                                &diagnostic_msg,
+                                vec![
+                                    (closure_body_span.shrink_to_lo(), format!("{{ {}; ", migration_string)),
+                                    (closure_body_span.shrink_to_hi(), " }".to_string()),
+                                ],
+                                Applicability::MachineApplicable
+                            );
+                        }
+                    } else {
+                        diagnostics_builder.span_suggestion(
+                            closure_span,
+                            &diagnostic_msg,
+                            migration_string,
+                            Applicability::HasPlaceholders
+                        );
+                    }
 
-                    diagnostics_builder.span_suggestion(
-                        span,
-                        &diagnostic_msg,
-                        sugg,
-                        app,
-                    );
                     diagnostics_builder.emit();
                 },
             );

library/alloc/tests/const_fns.rs

@@ -10,7 +10,7 @@ pub const MY_VEC: Vec<usize> = Vec::new();
 #[allow(dead_code)]
 pub const MY_STRING: String = String::new();
 
-// FIXME remove this struct once we put `K: ?const Ord` on BTreeMap::new.
+// FIXME(fee1-dead) remove this struct once we put `K: ?const Ord` on BTreeMap::new.
 #[derive(PartialEq, Eq, PartialOrd)]
 pub struct MyType;
 

library/alloc/tests/lib.rs

@@ -25,8 +25,6 @@
 #![feature(string_remove_matches)]
 #![feature(const_btree_new)]
 #![feature(const_trait_impl)]
-// FIXME remove this when const_trait_impl is not incomplete anymore
-#![allow(incomplete_features)]
 
 use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};