diff --git a/compiler/rustc_ast/src/token.rs b/compiler/rustc_ast/src/token.rs index dd98946b4cc5e..bfc4db32d3751 100644 --- a/compiler/rustc_ast/src/token.rs +++ b/compiler/rustc_ast/src/token.rs @@ -398,6 +398,30 @@ impl Token { } } + /// Returns `true` if the token can appear at the start of an pattern. + /// + /// Shamelessly borrowed from `can_begin_expr`, only used for diagnostics right now. + pub fn can_begin_pattern(&self) -> bool { + match self.uninterpolate().kind { + Ident(name, is_raw) => + ident_can_begin_expr(name, self.span, is_raw), // value name or keyword + | OpenDelim(Delimiter::Bracket | Delimiter::Parenthesis) // tuple or array + | Literal(..) // literal + | BinOp(Minus) // unary minus + | BinOp(And) // reference + | AndAnd // double reference + // DotDotDot is no longer supported + | DotDot | DotDotDot | DotDotEq // ranges + | Lt | BinOp(Shl) // associated path + | ModSep => true, // global path + Interpolated(ref nt) => matches!(**nt, NtLiteral(..) | + NtPat(..) | + NtBlock(..) | + NtPath(..)), + _ => false, + } + } + /// Returns `true` if the token can appear at the start of a type. pub fn can_begin_type(&self) -> bool { match self.uninterpolate().kind { diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index aabbe8ac276d7..b38684a63e410 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -386,7 +386,8 @@ pub fn from_fn_attrs<'ll, 'tcx>( ) { let span = cx .tcx - .get_attr(instance.def_id(), sym::target_feature) + .get_attrs(instance.def_id(), sym::target_feature) + .next() .map_or_else(|| cx.tcx.def_span(instance.def_id()), |a| a.span); let msg = format!( "the target features {} must all be either enabled or disabled together", diff --git a/compiler/rustc_error_messages/locales/en-US/parser.ftl b/compiler/rustc_error_messages/locales/en-US/parser.ftl index 3b37a393846b2..bc17754c56ae3 100644 --- a/compiler/rustc_error_messages/locales/en-US/parser.ftl +++ b/compiler/rustc_error_messages/locales/en-US/parser.ftl @@ -150,3 +150,6 @@ parser_dotdotdot = unexpected token: `...` parser_left_arrow_operator = unexpected token: `<-` .suggestion = if you meant to write a comparison against a negative value, add a space in between `<` and `-` + +parser_remove_let = expected pattern, found `let` + .suggestion = remove the unnecessary `let` keyword diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs index e359d50c4e9e5..38a02cb1d7ce9 100644 --- a/compiler/rustc_feature/src/builtin_attrs.rs +++ b/compiler/rustc_feature/src/builtin_attrs.rs @@ -823,6 +823,14 @@ pub fn is_builtin_only_local(name: Symbol) -> bool { BUILTIN_ATTRIBUTE_MAP.get(&name).map_or(false, |attr| attr.only_local) } +pub fn is_valid_for_get_attr(name: Symbol) -> bool { + BUILTIN_ATTRIBUTE_MAP.get(&name).map_or(false, |attr| match attr.duplicates { + WarnFollowing | ErrorFollowing | ErrorPreceding | FutureWarnFollowing + | FutureWarnPreceding => true, + DuplicatesOk | WarnFollowingWordOnly => false, + }) +} + pub static BUILTIN_ATTRIBUTE_MAP: LazyLock> = LazyLock::new(|| { let mut map = FxHashMap::default(); diff --git a/compiler/rustc_feature/src/lib.rs b/compiler/rustc_feature/src/lib.rs index e44c9291f8483..bdaa0ee88eba1 100644 --- a/compiler/rustc_feature/src/lib.rs +++ b/compiler/rustc_feature/src/lib.rs @@ -151,7 +151,7 @@ pub use active::{Features, ACTIVE_FEATURES, INCOMPATIBLE_FEATURES}; pub use builtin_attrs::AttributeDuplicates; pub use builtin_attrs::{ deprecated_attributes, find_gated_cfg, is_builtin_attr_name, is_builtin_only_local, - AttributeGate, AttributeTemplate, AttributeType, BuiltinAttribute, GatedCfg, - BUILTIN_ATTRIBUTES, BUILTIN_ATTRIBUTE_MAP, + is_valid_for_get_attr, AttributeGate, AttributeTemplate, AttributeType, BuiltinAttribute, + GatedCfg, BUILTIN_ATTRIBUTES, BUILTIN_ATTRIBUTE_MAP, }; pub use removed::{REMOVED_FEATURES, STABLE_REMOVED_FEATURES}; diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index ed04e7660339e..58b0657a5b01f 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -2274,7 +2274,11 @@ impl<'tcx> TyCtxt<'tcx> { } pub fn get_attr(self, did: DefId, attr: Symbol) -> Option<&'tcx ast::Attribute> { - self.get_attrs(did, attr).next() + if cfg!(debug_assertions) && !rustc_feature::is_valid_for_get_attr(attr) { + bug!("get_attr: unexpected called with DefId `{:?}`, attr `{:?}`", did, attr); + } else { + self.get_attrs(did, attr).next() + } } /// Determines whether an item is annotated with an attribute. diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index dd806e2130e9b..a299ee0a1046a 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -705,6 +705,14 @@ pub(crate) struct LeftArrowOperator { pub span: Span, } +#[derive(SessionDiagnostic)] +#[diag(parser::remove_let)] +pub(crate) struct RemoveLet { + #[primary_span] + #[suggestion(applicability = "machine-applicable", code = "")] + pub span: Span, +} + // SnapshotParser is used to create a snapshot of the parser // without causing duplicate errors being emitted when the `Parser` // is dropped. diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs index 8b3200d45fccd..6c8f3f664e253 100644 --- a/compiler/rustc_parse/src/parser/pat.rs +++ b/compiler/rustc_parse/src/parser/pat.rs @@ -1,4 +1,5 @@ use super::{ForceCollect, Parser, PathStyle, TrailingToken}; +use crate::parser::diagnostics::RemoveLet; use crate::{maybe_recover_from_interpolated_ty_qpath, maybe_whole}; use rustc_ast::mut_visit::{noop_visit_pat, MutVisitor}; use rustc_ast::ptr::P; @@ -320,7 +321,13 @@ impl<'a> Parser<'a> { maybe_recover_from_interpolated_ty_qpath!(self, true); maybe_whole!(self, NtPat, |x| x); - let lo = self.token.span; + let mut lo = self.token.span; + + if self.token.is_keyword(kw::Let) && self.look_ahead(1, |tok| tok.can_begin_pattern()) { + self.bump(); + self.sess.emit_err(RemoveLet { span: lo }); + lo = self.token.span; + } let pat = if self.check(&token::BinOp(token::And)) || self.token.kind == token::AndAnd { self.parse_pat_deref(expected)? diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs index 29a128f27b840..d52dccbfa4df8 100644 --- a/compiler/rustc_typeck/src/check/check.rs +++ b/compiler/rustc_typeck/src/check/check.rs @@ -1464,7 +1464,7 @@ fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, vs: &'tcx [hir::Variant<'tcx>], def_id: L def.destructor(tcx); // force the destructor to be evaluated if vs.is_empty() { - if let Some(attr) = tcx.get_attr(def_id.to_def_id(), sym::repr) { + if let Some(attr) = tcx.get_attrs(def_id.to_def_id(), sym::repr).next() { struct_span_err!( tcx.sess, attr.span, diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs index d1d27db9131fd..fc3596113f03b 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs @@ -1811,16 +1811,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { return true; } } - // Notably, we only point to params that are local to the - // item we're checking, since those are the ones we are able - // to look in the final `hir::PathSegment` for. Everything else - // would require a deeper search into the `qpath` than I think - // is worthwhile. - if let Some(param_to_point_at) = param_to_point_at - && self.point_at_path_if_possible(error, def_id, param_to_point_at, qpath) - { - return true; - } + } + // Notably, we only point to params that are local to the + // item we're checking, since those are the ones we are able + // to look in the final `hir::PathSegment` for. Everything else + // would require a deeper search into the `qpath` than I think + // is worthwhile. + if let Some(param_to_point_at) = param_to_point_at + && self.point_at_path_if_possible(error, def_id, param_to_point_at, qpath) + { + return true; } } hir::ExprKind::MethodCall(segment, args, ..) => { diff --git a/library/std/src/io/stdio.rs b/library/std/src/io/stdio.rs index dd4ff4952fde9..91cff3217d21b 100644 --- a/library/std/src/io/stdio.rs +++ b/library/std/src/io/stdio.rs @@ -607,15 +607,24 @@ pub fn stdout() -> Stdout { } } +// Flush the data and disable buffering during shutdown +// by replacing the line writer by one with zero +// buffering capacity. pub fn cleanup() { - // Flush the data and disable buffering during shutdown - // by replacing the line writer by one with zero - // buffering capacity. - // We use try_lock() instead of lock(), because someone - // might have leaked a StdoutLock, which would - // otherwise cause a deadlock here. - if let Some(lock) = STDOUT.get().and_then(ReentrantMutex::try_lock) { - *lock.borrow_mut() = LineWriter::with_capacity(0, stdout_raw()); + let mut initialized = false; + let stdout = STDOUT.get_or_init(|| { + initialized = true; + ReentrantMutex::new(RefCell::new(LineWriter::with_capacity(0, stdout_raw()))) + }); + + if !initialized { + // The buffer was previously initialized, overwrite it here. + // We use try_lock() instead of lock(), because someone + // might have leaked a StdoutLock, which would + // otherwise cause a deadlock here. + if let Some(lock) = stdout.try_lock() { + *lock.borrow_mut() = LineWriter::with_capacity(0, stdout_raw()); + } } } diff --git a/src/test/ui/issues/issue-100631.rs b/src/test/ui/issues/issue-100631.rs new file mode 100644 index 0000000000000..0fefcf83fd516 --- /dev/null +++ b/src/test/ui/issues/issue-100631.rs @@ -0,0 +1,8 @@ +// issue #100631, make sure `TyCtxt::get_attr` only called by case that compiler +// can reasonably deal with multiple attributes. +// `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`. +#[repr(C)] //~ ERROR: unsupported representation for zero-variant enum [E0084] +#[repr(C)] +enum Foo {} + +fn main() {} diff --git a/src/test/ui/issues/issue-100631.stderr b/src/test/ui/issues/issue-100631.stderr new file mode 100644 index 0000000000000..caa5351ddc7aa --- /dev/null +++ b/src/test/ui/issues/issue-100631.stderr @@ -0,0 +1,12 @@ +error[E0084]: unsupported representation for zero-variant enum + --> $DIR/issue-100631.rs:4:1 + | +LL | #[repr(C)] + | ^^^^^^^^^^ +LL | #[repr(C)] +LL | enum Foo {} + | -------- zero-variant enum + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0084`. diff --git a/src/test/ui/let-else/let-else-drop-order.rs b/src/test/ui/let-else/let-else-drop-order.rs new file mode 100644 index 0000000000000..0054f3d4182ec --- /dev/null +++ b/src/test/ui/let-else/let-else-drop-order.rs @@ -0,0 +1,270 @@ +// run-pass +// edition:2021 +// check-run-results +// +// Drop order tests for let else +// +// Mostly this ensures two things: +// 1. That let and let else temporary drop order is the same. +// This is a specific design request: https://github.com/rust-lang/rust/pull/93628#issuecomment-1047140316 +// 2. That the else block truly only runs after the +// temporaries have dropped. +// +// We also print some nice tables for an overview by humans. +// Changes in those tables are considered breakages, but the +// important properties 1 and 2 are also enforced by the code. +// This is important as it's easy to update the stdout file +// with a --bless and miss the impact of that change. + +#![feature(let_else)] +#![allow(irrefutable_let_patterns)] + +use std::cell::RefCell; +use std::rc::Rc; + +#[derive(Clone)] +struct DropAccountant(Rc>>>); + +impl DropAccountant { + fn new() -> Self { + Self(Default::default()) + } + fn build_droppy(&self, v: u32) -> Droppy { + Droppy(self.clone(), v) + } + fn build_droppy_enum_none(&self, _v: u32) -> ((), DroppyEnum) { + ((), DroppyEnum::None(self.clone())) + } + fn new_list(&self, s: impl ToString) { + self.0.borrow_mut().push(vec![s.to_string()]); + } + fn push(&self, s: impl ToString) { + let s = s.to_string(); + let mut accounts = self.0.borrow_mut(); + accounts.last_mut().unwrap().push(s); + } + fn print_table(&self) { + println!(); + + let accounts = self.0.borrow(); + let before_last = &accounts[accounts.len() - 2]; + let last = &accounts[accounts.len() - 1]; + let before_last = get_comma_list(before_last); + let last = get_comma_list(last); + const LINES: &[&str] = &[ + "vanilla", + "&", + "&mut", + "move", + "fn(this)", + "tuple", + "array", + "ref &", + "ref mut &mut", + ]; + let max_len = LINES.iter().map(|v| v.len()).max().unwrap(); + let max_len_before = before_last.iter().map(|v| v.len()).max().unwrap(); + let max_len_last = last.iter().map(|v| v.len()).max().unwrap(); + + println!( + "| {: Vec { + std::iter::once(sl[0].clone()) + .chain(sl[1..].chunks(2).map(|c| c.join(","))) + .collect::>() +} + +struct Droppy(DropAccountant, T); + +impl Drop for Droppy { + fn drop(&mut self) { + self.0.push("drop"); + } +} + +#[allow(dead_code)] +enum DroppyEnum { + Some(DropAccountant, T), + None(DropAccountant), +} + +impl Drop for DroppyEnum { + fn drop(&mut self) { + match self { + DroppyEnum::Some(acc, _inner) => acc, + DroppyEnum::None(acc) => acc, + } + .push("drop"); + } +} + +macro_rules! nestings_with { + ($construct:ident, $binding:pat, $exp:expr) => { + // vanilla: + $construct!($binding, $exp.1); + + // &: + $construct!(&$binding, &$exp.1); + + // &mut: + $construct!(&mut $binding, &mut ($exp.1)); + + { + // move: + let w = $exp; + $construct!( + $binding, + { + let w = w; + w + } + .1 + ); + } + + // fn(this): + $construct!($binding, std::convert::identity($exp).1); + }; +} + +macro_rules! nestings { + ($construct:ident, $binding:pat, $exp:expr) => { + nestings_with!($construct, $binding, $exp); + + // tuple: + $construct!(($binding, 77), ($exp.1, 77)); + + // array: + $construct!([$binding], [$exp.1]); + }; +} + +macro_rules! let_else { + ($acc:expr, $v:expr, $binding:pat, $build:ident) => { + let acc = $acc; + let v = $v; + + macro_rules! let_else_construct { + ($arg:pat, $exp:expr) => { + loop { + let $arg = $exp else { + acc.push("else"); + break; + }; + acc.push("body"); + break; + } + }; + } + nestings!(let_else_construct, $binding, acc.$build(v)); + // ref &: + let_else_construct!($binding, &acc.$build(v).1); + + // ref mut &mut: + let_else_construct!($binding, &mut acc.$build(v).1); + }; +} + +macro_rules! let_ { + ($acc:expr, $binding:tt) => { + let acc = $acc; + + macro_rules! let_construct { + ($arg:pat, $exp:expr) => {{ + let $arg = $exp; + acc.push("body"); + }}; + } + let v = 0; + { + nestings_with!(let_construct, $binding, acc.build_droppy(v)); + } + acc.push("n/a"); + acc.push("n/a"); + acc.push("n/a"); + acc.push("n/a"); + + // ref &: + let_construct!($binding, &acc.build_droppy(v).1); + + // ref mut &mut: + let_construct!($binding, &mut acc.build_droppy(v).1); + }; +} + +fn main() { + let acc = DropAccountant::new(); + + println!(" --- matching cases ---"); + + // Ensure that let and let else have the same behaviour + acc.new_list("let _"); + let_!(&acc, _); + acc.new_list("let else _"); + let_else!(&acc, 0, _, build_droppy); + acc.assert_equality_last_two_lists(); + acc.print_table(); + + // Ensure that let and let else have the same behaviour + acc.new_list("let _v"); + let_!(&acc, _v); + acc.new_list("let else _v"); + let_else!(&acc, 0, _v, build_droppy); + acc.assert_equality_last_two_lists(); + acc.print_table(); + + println!(); + + println!(" --- mismatching cases ---"); + + acc.new_list("let else _ mismatch"); + let_else!(&acc, 1, DroppyEnum::Some(_, _), build_droppy_enum_none); + acc.new_list("let else _v mismatch"); + let_else!(&acc, 1, DroppyEnum::Some(_, _v), build_droppy_enum_none); + acc.print_table(); + // This ensures that we always drop before visiting the else case + acc.assert_all_equal_to("drop,else"); + + acc.new_list("let else 0 mismatch"); + let_else!(&acc, 1, 0, build_droppy); + acc.new_list("let else 0 mismatch"); + let_else!(&acc, 1, 0, build_droppy); + acc.print_table(); + // This ensures that we always drop before visiting the else case + acc.assert_all_equal_to("drop,else"); +} diff --git a/src/test/ui/let-else/let-else-drop-order.run.stdout b/src/test/ui/let-else/let-else-drop-order.run.stdout new file mode 100644 index 0000000000000..01cf2f73e17c9 --- /dev/null +++ b/src/test/ui/let-else/let-else-drop-order.run.stdout @@ -0,0 +1,51 @@ + --- matching cases --- + +| construct | let _ | let else _ | +| ------------ | --------- | ---------- | +| vanilla | drop,body | drop,body | +| & | body,drop | body,drop | +| &mut | body,drop | body,drop | +| move | drop,body | drop,body | +| fn(this) | drop,body | drop,body | +| tuple | n/a,n/a | drop,body | +| array | n/a,n/a | drop,body | +| ref & | body,drop | body,drop | +| ref mut &mut | body,drop | body,drop | + +| construct | let _v | let else _v | +| ------------ | --------- | ----------- | +| vanilla | drop,body | drop,body | +| & | body,drop | body,drop | +| &mut | body,drop | body,drop | +| move | drop,body | drop,body | +| fn(this) | drop,body | drop,body | +| tuple | n/a,n/a | drop,body | +| array | n/a,n/a | drop,body | +| ref & | body,drop | body,drop | +| ref mut &mut | body,drop | body,drop | + + --- mismatching cases --- + +| construct | let else _ mismatch | let else _v mismatch | +| ------------ | ------------------- | -------------------- | +| vanilla | drop,else | drop,else | +| & | drop,else | drop,else | +| &mut | drop,else | drop,else | +| move | drop,else | drop,else | +| fn(this) | drop,else | drop,else | +| tuple | drop,else | drop,else | +| array | drop,else | drop,else | +| ref & | drop,else | drop,else | +| ref mut &mut | drop,else | drop,else | + +| construct | let else 0 mismatch | let else 0 mismatch | +| ------------ | ------------------- | ------------------- | +| vanilla | drop,else | drop,else | +| & | drop,else | drop,else | +| &mut | drop,else | drop,else | +| move | drop,else | drop,else | +| fn(this) | drop,else | drop,else | +| tuple | drop,else | drop,else | +| array | drop,else | drop,else | +| ref & | drop,else | drop,else | +| ref mut &mut | drop,else | drop,else | diff --git a/src/test/ui/parser/unnecessary-let.rs b/src/test/ui/parser/unnecessary-let.rs new file mode 100644 index 0000000000000..6279109621d70 --- /dev/null +++ b/src/test/ui/parser/unnecessary-let.rs @@ -0,0 +1,11 @@ +fn main() { + for let x of [1, 2, 3] {} + //~^ ERROR expected pattern, found `let` + //~| ERROR missing `in` in `for` loop + + match 1 { + let 1 => {} + //~^ ERROR expected pattern, found `let` + _ => {} + } +} diff --git a/src/test/ui/parser/unnecessary-let.stderr b/src/test/ui/parser/unnecessary-let.stderr new file mode 100644 index 0000000000000..952119cae3e27 --- /dev/null +++ b/src/test/ui/parser/unnecessary-let.stderr @@ -0,0 +1,20 @@ +error: expected pattern, found `let` + --> $DIR/unnecessary-let.rs:2:9 + | +LL | for let x of [1, 2, 3] {} + | ^^^ help: remove the unnecessary `let` keyword + +error: missing `in` in `for` loop + --> $DIR/unnecessary-let.rs:2:15 + | +LL | for let x of [1, 2, 3] {} + | ^^ help: try using `in` here instead + +error: expected pattern, found `let` + --> $DIR/unnecessary-let.rs:7:9 + | +LL | let 1 => {} + | ^^^ help: remove the unnecessary `let` keyword + +error: aborting due to 3 previous errors + diff --git a/src/test/ui/typeck/point-at-type-param-in-path-expr.rs b/src/test/ui/typeck/point-at-type-param-in-path-expr.rs new file mode 100644 index 0000000000000..9a21536f9b12b --- /dev/null +++ b/src/test/ui/typeck/point-at-type-param-in-path-expr.rs @@ -0,0 +1,6 @@ +fn foo() {} + +fn main() { + let x = foo::<()>; + //~^ ERROR `()` doesn't implement `std::fmt::Display` +} diff --git a/src/test/ui/typeck/point-at-type-param-in-path-expr.stderr b/src/test/ui/typeck/point-at-type-param-in-path-expr.stderr new file mode 100644 index 0000000000000..1feaa0508bfa7 --- /dev/null +++ b/src/test/ui/typeck/point-at-type-param-in-path-expr.stderr @@ -0,0 +1,17 @@ +error[E0277]: `()` doesn't implement `std::fmt::Display` + --> $DIR/point-at-type-param-in-path-expr.rs:4:19 + | +LL | let x = foo::<()>; + | ^^ `()` cannot be formatted with the default formatter + | + = help: the trait `std::fmt::Display` is not implemented for `()` + = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead +note: required by a bound in `foo` + --> $DIR/point-at-type-param-in-path-expr.rs:1:11 + | +LL | fn foo() {} + | ^^^^^^^^^^^^^^^^^ required by this bound in `foo` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`. diff --git a/triagebot.toml b/triagebot.toml index 89d1574726f09..89edab91fcd70 100644 --- a/triagebot.toml +++ b/triagebot.toml @@ -316,9 +316,6 @@ Examples of `T-libs-api` changes: * Changing observable runtime behavior of library APIs """ -[mentions."library/proc_macro/src/bridge"] -cc = ["@rust-lang/wg-rls-2"] - [mentions."src/librustdoc/clean/types.rs"] cc = ["@camelid"]