Auto merge of #116688 - compiler-errors:rustfmt-up, r=WaffleLapkin,Ni…

…lstrieb

Format all the let-chains in compiler crates

Since rust-lang/rustfmt#5910 has landed, soon we will have support for formatting let-chains (as soon as rustfmt syncs and beta gets bumped).

This PR applies the changes [from master rustfmt to rust-lang/rust eagerly](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/out.20formatting.20of.20prs/near/374997516), so that the next beta bump does not have to deal with a 200+ file diff and can remain concerned with other things like `cfg(bootstrap)` -- #113637 was a pain to land, for example, because of let-else.

I will also add this commit to the ignore list after it has landed.

The commands that were run -- I'm not great at bash-foo, but this applies rustfmt to every compiler crate, and then reverts the two crates that should probably be formatted out-of-tree.
```
~/rustfmt $ ls -1d ~/rust/compiler/* | xargs -I@ cargo run --bin rustfmt -- `@/src/lib.rs` --config-path ~/rust --edition=2021 # format all of the compiler crates
~/rust $ git checkout HEAD -- compiler/rustc_codegen_{gcc,cranelift} # revert changes to cg-gcc and cg-clif
```

cc `@rust-lang/rustfmt`
r? `@WaffleLapkin` or `@Nilstrieb` who said they may be able to review this purely mechanical PR :>

cc `@Mark-Simulacrum` and `@petrochenkov,` who had some thoughts on the order of operations with big formatting changes in #95262 (comment). I think the situation has changed since then, given that let-chains support exists on master rustfmt now, and I'm fairly confident that this formatting PR should land even if *bootstrap* rustfmt doesn't yet format let-chains in order to lessen the burden of the next beta bump.

compiler/rustc_ast/src/attr/mod.rs

@@ -520,9 +520,7 @@ impl NestedMetaItem {
         I: Iterator<Item = &'a TokenTree>,
     {
         match tokens.peek() {
-            Some(TokenTree::Token(token, _))
-                if let Some(lit) = MetaItemLit::from_token(token) =>
-            {
+            Some(TokenTree::Token(token, _)) if let Some(lit) = MetaItemLit::from_token(token) => {
                 tokens.next();
                 return Some(NestedMetaItem::Lit(lit));
             }

compiler/rustc_ast/src/entry.rs

@@ -21,7 +21,9 @@ pub fn entry_point_type(
     } else if attr::contains_name(attrs, sym::rustc_main) {
         EntryPointType::RustcMainAttr
     } else {
-        if let Some(name) = name && name == sym::main {
+        if let Some(name) = name
+            && name == sym::main
+        {
             if at_root {
                 // This is a top-level function so it can be `main`.
                 EntryPointType::MainNamed

compiler/rustc_ast/src/token.rs

@@ -107,13 +107,11 @@ impl Lit {
     /// Keep this in sync with `Token::can_begin_literal_or_bool` excluding unary negation.
     pub fn from_token(token: &Token) -> Option<Lit> {
         match token.uninterpolate().kind {
-            Ident(name, false) if name.is_bool_lit() => {
-                Some(Lit::new(Bool, name, None))
-            }
+            Ident(name, false) if name.is_bool_lit() => Some(Lit::new(Bool, name, None)),
             Literal(token_lit) => Some(token_lit),
             Interpolated(ref nt)
                 if let NtExpr(expr) | NtLiteral(expr) = &**nt
-                && let ast::ExprKind::Lit(token_lit) = expr.kind =>
+                    && let ast::ExprKind::Lit(token_lit) = expr.kind =>
             {
                 Some(token_lit)
             }
@@ -655,7 +653,9 @@ impl Token {
 
     /// Returns `true` if the token is an interpolated path.
     fn is_path(&self) -> bool {
-        if let Interpolated(nt) = &self.kind && let NtPath(..) = **nt {
+        if let Interpolated(nt) = &self.kind
+            && let NtPath(..) = **nt
+        {
             return true;
         }
 
@@ -677,7 +677,9 @@ impl Token {
 
     /// Is the token an interpolated block (`$b:block`)?
     pub fn is_whole_block(&self) -> bool {
-        if let Interpolated(nt) = &self.kind && let NtBlock(..) = **nt {
+        if let Interpolated(nt) = &self.kind
+            && let NtBlock(..) = **nt
+        {
             return true;
         }
 

compiler/rustc_ast/src/tokenstream.rs

@@ -550,7 +550,9 @@ impl TokenStream {
 
         let stream_iter = stream.0.iter().cloned();
 
-        if let Some(first) = stream.0.first() && Self::try_glue_to_last(vec_mut, first) {
+        if let Some(first) = stream.0.first()
+            && Self::try_glue_to_last(vec_mut, first)
+        {
             // Now skip the first token tree from `stream`.
             vec_mut.extend(stream_iter.skip(1));
         } else {

compiler/rustc_ast_lowering/src/expr.rs

@@ -673,12 +673,18 @@ impl<'hir> LoweringContext<'_, 'hir> {
             && let Some(attrs) = self.attrs.get(&outer_hir_id.local_id)
             && attrs.into_iter().any(|attr| attr.has_name(sym::track_caller))
         {
-            let unstable_span =
-                self.mark_span_with_reason(DesugaringKind::Async, span, self.allow_gen_future.clone());
+            let unstable_span = self.mark_span_with_reason(
+                DesugaringKind::Async,
+                span,
+                self.allow_gen_future.clone(),
+            );
             self.lower_attrs(
                 inner_hir_id,
                 &[Attribute {
-                    kind: AttrKind::Normal(ptr::P(NormalAttr::from_ident(Ident::new(sym::track_caller, span)))),
+                    kind: AttrKind::Normal(ptr::P(NormalAttr::from_ident(Ident::new(
+                        sym::track_caller,
+                        span,
+                    )))),
                     id: self.tcx.sess.parse_sess.attr_id_generator.mk_attr_id(),
                     style: AttrStyle::Outer,
                     span: unstable_span,
@@ -1102,7 +1108,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
         if let ExprKind::Path(qself, path) = &expr.kind {
             // Does the path resolve to something disallowed in a tuple struct/variant pattern?
             if let Some(partial_res) = self.resolver.get_partial_res(expr.id) {
-                if let Some(res) = partial_res.full_res() && !res.expected_in_tuple_struct_pat() {
+                if let Some(res) = partial_res.full_res()
+                    && !res.expected_in_tuple_struct_pat()
+                {
                     return None;
                 }
             }
@@ -1122,7 +1130,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
         if let ExprKind::Path(qself, path) = &expr.kind {
             // Does the path resolve to something disallowed in a unit struct/variant pattern?
             if let Some(partial_res) = self.resolver.get_partial_res(expr.id) {
-                if let Some(res) = partial_res.full_res() && !res.expected_in_unit_struct_pat() {
+                if let Some(res) = partial_res.full_res()
+                    && !res.expected_in_unit_struct_pat()
+                {
                     return None;
                 }
             }

compiler/rustc_ast_lowering/src/format.rs

@@ -61,9 +61,12 @@ fn flatten_format_args(mut fmt: Cow<'_, FormatArgs>) -> Cow<'_, FormatArgs> {
             let remaining_args = args.split_off(arg_index + 1);
             let old_arg_offset = args.len();
             let mut fmt2 = &mut args.pop().unwrap().expr; // The inner FormatArgs.
-            let fmt2 = loop { // Unwrap the Expr to get to the FormatArgs.
+            let fmt2 = loop {
+                // Unwrap the Expr to get to the FormatArgs.
                 match &mut fmt2.kind {
-                    ExprKind::Paren(inner) | ExprKind::AddrOf(BorrowKind::Ref, _, inner) => fmt2 = inner,
+                    ExprKind::Paren(inner) | ExprKind::AddrOf(BorrowKind::Ref, _, inner) => {
+                        fmt2 = inner
+                    }
                     ExprKind::FormatArgs(fmt2) => break fmt2,
                     _ => unreachable!(),
                 }

compiler/rustc_ast_lowering/src/item.rs

@@ -1387,10 +1387,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // Desugar `~const` bound in generics into an additional `const host: bool` param
         // if the effects feature is enabled. This needs to be done before we lower where
         // clauses since where clauses need to bind to the DefId of the host param
-        let host_param_parts = if let Const::Yes(span) = constness && self.tcx.features().effects {
-            if let Some(param) = generics.params.iter().find(|x| {
-                x.attrs.iter().any(|x| x.has_name(sym::rustc_host))
-            }) {
+        let host_param_parts = if let Const::Yes(span) = constness
+            && self.tcx.features().effects
+        {
+            if let Some(param) =
+                generics.params.iter().find(|x| x.attrs.iter().any(|x| x.has_name(sym::rustc_host)))
+            {
                 // user has manually specified a `rustc_host` param, in this case, we set
                 // the param id so that lowering logic can use that. But we don't create
                 // another host param, so this gives `None`.
@@ -1399,7 +1401,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
             } else {
                 let param_node_id = self.next_node_id();
                 let hir_id = self.next_id();
-                let def_id = self.create_def(self.local_def_id(parent_node_id), param_node_id, DefPathData::TypeNs(sym::host), span);
+                let def_id = self.create_def(
+                    self.local_def_id(parent_node_id),
+                    param_node_id,
+                    DefPathData::TypeNs(sym::host),
+                    span,
+                );
                 self.host_param_id = Some(def_id);
                 Some((span, hir_id, def_id))
             }

compiler/rustc_ast_lowering/src/lib.rs

@@ -1256,7 +1256,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     &PolyTraitRef {
                         bound_generic_params: ThinVec::new(),
                         trait_ref: TraitRef { path: path.clone(), ref_id: t.id },
-                        span: t.span
+                        span: t.span,
                     },
                     itctx,
                     ast::Const::No,

compiler/rustc_ast_lowering/src/lifetime_collector.rs

@@ -82,7 +82,8 @@ impl<'ast> Visitor<'ast> for LifetimeCollectVisitor<'ast> {
                 // We can sometimes encounter bare trait objects
                 // which are represented in AST as paths.
                 if let Some(partial_res) = self.resolver.get_partial_res(t.id)
-                    && let Some(Res::Def(DefKind::Trait | DefKind::TraitAlias, _)) = partial_res.full_res()
+                    && let Some(Res::Def(DefKind::Trait | DefKind::TraitAlias, _)) =
+                        partial_res.full_res()
                 {
                     self.current_binders.push(t.id);
                     visit::walk_ty(self, t);

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -215,14 +215,15 @@ impl<'a> AstValidator<'a> {
     }
 
     fn visit_struct_field_def(&mut self, field: &'a FieldDef) {
-        if let Some(ident) = field.ident &&
-            ident.name == kw::Underscore {
-                self.check_unnamed_field_ty(&field.ty, ident.span);
-                self.visit_vis(&field.vis);
-                self.visit_ident(ident);
-                self.visit_ty_common(&field.ty);
-                self.walk_ty(&field.ty);
-                walk_list!(self, visit_attribute, &field.attrs);
+        if let Some(ident) = field.ident
+            && ident.name == kw::Underscore
+        {
+            self.check_unnamed_field_ty(&field.ty, ident.span);
+            self.visit_vis(&field.vis);
+            self.visit_ident(ident);
+            self.visit_ty_common(&field.ty);
+            self.walk_ty(&field.ty);
+            walk_list!(self, visit_attribute, &field.attrs);
         } else {
             self.visit_field_def(field);
         }
@@ -291,13 +292,11 @@ impl<'a> AstValidator<'a> {
     }
 
     fn deny_unnamed_field(&self, field: &FieldDef) {
-        if let Some(ident) = field.ident &&
-            ident.name == kw::Underscore {
-                self.err_handler()
-                    .emit_err(errors::InvalidUnnamedField {
-                        span: field.span,
-                        ident_span: ident.span
-                    });
+        if let Some(ident) = field.ident
+            && ident.name == kw::Underscore
+        {
+            self.err_handler()
+                .emit_err(errors::InvalidUnnamedField { span: field.span, ident_span: ident.span });
         }
     }
 
@@ -1180,28 +1179,40 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 (BoundKind::SuperTraits, TraitBoundModifier::Maybe) => {
                     self.err_handler().emit_err(errors::OptionalTraitSupertrait {
                         span: poly.span,
-                        path_str: pprust::path_to_string(&poly.trait_ref.path)
+                        path_str: pprust::path_to_string(&poly.trait_ref.path),
                     });
                 }
                 (BoundKind::TraitObject, TraitBoundModifier::Maybe) => {
-                    self.err_handler().emit_err(errors::OptionalTraitObject {span: poly.span});
+                    self.err_handler().emit_err(errors::OptionalTraitObject { span: poly.span });
                 }
-                (_, TraitBoundModifier::MaybeConst) if let Some(reason) = &self.disallow_tilde_const => {
+                (_, TraitBoundModifier::MaybeConst)
+                    if let Some(reason) = &self.disallow_tilde_const =>
+                {
                     let reason = match reason {
-                        DisallowTildeConstContext::TraitObject => errors::TildeConstReason::TraitObject,
-                        DisallowTildeConstContext::Fn(FnKind::Closure(..)) => errors::TildeConstReason::Closure,
-                        DisallowTildeConstContext::Fn(FnKind::Fn(_, ident, ..)) => errors::TildeConstReason::Function { ident: ident.span },
+                        DisallowTildeConstContext::TraitObject => {
+                            errors::TildeConstReason::TraitObject
+                        }
+                        DisallowTildeConstContext::Fn(FnKind::Closure(..)) => {
+                            errors::TildeConstReason::Closure
+                        }
+                        DisallowTildeConstContext::Fn(FnKind::Fn(_, ident, ..)) => {
+                            errors::TildeConstReason::Function { ident: ident.span }
+                        }
                     };
-                    self.err_handler().emit_err(errors::TildeConstDisallowed {
-                        span: bound.span(),
-                        reason
-                    });
+                    self.err_handler()
+                        .emit_err(errors::TildeConstDisallowed { span: bound.span(), reason });
                 }
                 (_, TraitBoundModifier::MaybeConstMaybe) => {
-                    self.err_handler().emit_err(errors::OptionalConstExclusive {span: bound.span(), modifier: "?" });
+                    self.err_handler().emit_err(errors::OptionalConstExclusive {
+                        span: bound.span(),
+                        modifier: "?",
+                    });
                 }
                 (_, TraitBoundModifier::MaybeConstNegative) => {
-                    self.err_handler().emit_err(errors::OptionalConstExclusive {span: bound.span(), modifier: "!" });
+                    self.err_handler().emit_err(errors::OptionalConstExclusive {
+                        span: bound.span(),
+                        modifier: "!",
+                    });
                 }
                 _ => {}
             }
@@ -1214,7 +1225,8 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         {
             for arg in &args.args {
                 if let ast::AngleBracketedArg::Constraint(constraint) = arg {
-                    self.err_handler().emit_err(errors::ConstraintOnNegativeBound { span: constraint.span });
+                    self.err_handler()
+                        .emit_err(errors::ConstraintOnNegativeBound { span: constraint.span });
                 }
             }
         }

compiler/rustc_attr/src/builtin.rs

@@ -405,7 +405,9 @@ fn parse_stability(sess: &Session, attr: &Attribute) -> Option<(Symbol, Stabilit
         }
     }
 
-    if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
+    if let Some(s) = since
+        && s.as_str() == VERSION_PLACEHOLDER
+    {
         since = Some(rust_version_symbol());
     }
 
@@ -694,13 +696,16 @@ pub fn eval_condition(
                     !eval_condition(mis[0].meta_item().unwrap(), sess, features, eval)
                 }
                 sym::target => {
-                    if let Some(features) = features && !features.cfg_target_compact {
+                    if let Some(features) = features
+                        && !features.cfg_target_compact
+                    {
                         feature_err(
                             sess,
                             sym::cfg_target_compact,
                             cfg.span,
-                            "compact `cfg(target(..))` is experimental and subject to change"
-                        ).emit();
+                            "compact `cfg(target(..))` is experimental and subject to change",
+                        )
+                        .emit();
                     }
 
                     mis.iter().fold(true, |res, mi| {