Rollup of 8 pull requests

RELEASES.md

@@ -156,6 +156,7 @@ Language
 - [Macro attributes may follow `#[derive]` and will see the original (pre-`cfg`) input.][87220]
 - [Accept curly-brace macros in expressions, like `m!{ .. }.method()` and `m!{ .. }?`.][88690]
 - [Allow panicking in constant evaluation.][89508]
+- [Ignore derived `Clone` and `Debug` implementations during dead code analysis.][85200]
 
 Compiler
 --------
@@ -216,6 +217,9 @@ Cargo
 Compatibility notes
 -------------------
 
+- [Ignore derived `Clone` and `Debug` implementations during dead code analysis.][85200]
+  This will break some builds that set `#![deny(dead_code)]`.
+
 Internal changes
 ----------------
 These changes provide no direct user facing benefits, but represent significant
@@ -224,6 +228,7 @@ and related tools.
 
 - [Added an experimental backend for codegen with `libgccjit`.][87260]
 
+[85200]: https://github.com/rust-lang/rust/pull/85200/
 [86191]: https://github.com/rust-lang/rust/pull/86191/
 [87220]: https://github.com/rust-lang/rust/pull/87220/
 [87260]: https://github.com/rust-lang/rust/pull/87260/

compiler/rustc_ast_pretty/src/pp/convenience.rs

@@ -75,6 +75,10 @@ impl Printer {
     }
 
     pub fn trailing_comma(&mut self) {
+        self.scan_break(BreakToken { pre_break: Some(','), ..BreakToken::default() });
+    }
+
+    pub fn trailing_comma_or_space(&mut self) {
         self.scan_break(BreakToken {
             blank_space: 1,
             pre_break: Some(','),

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

@@ -142,7 +142,7 @@ impl<'a> State<'a> {
             if !field.is_last || has_rest {
                 self.word_space(",");
             } else {
-                self.trailing_comma();
+                self.trailing_comma_or_space();
             }
         }
         if has_rest {

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

@@ -1,5 +1,6 @@
 use crate::pp::Breaks::Inconsistent;
-use crate::pprust::state::{AnnNode, PrintState, State};
+use crate::pprust::state::delimited::IterDelimited;
+use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
 
 use rustc_ast as ast;
 use rustc_ast::GenericBound;
@@ -138,11 +139,10 @@ impl<'a> State<'a> {
                 self.end(); // end outer head-block
             }
             ast::ItemKind::Use(ref tree) => {
-                self.head(visibility_qualified(&item.vis, "use"));
+                self.print_visibility(&item.vis);
+                self.word_nbsp("use");
                 self.print_use_tree(tree);
                 self.word(";");
-                self.end(); // end inner head-block
-                self.end(); // end outer head-block
             }
             ast::ItemKind::Static(ref ty, mutbl, ref body) => {
                 let def = ast::Defaultness::Final;
@@ -615,8 +615,8 @@ impl<'a> State<'a> {
             ast::UseTreeKind::Simple(rename, ..) => {
                 self.print_path(&tree.prefix, false, 0);
                 if let Some(rename) = rename {
-                    self.space();
-                    self.word_space("as");
+                    self.nbsp();
+                    self.word_nbsp("as");
                     self.print_ident(rename);
                 }
             }
@@ -628,16 +628,36 @@ impl<'a> State<'a> {
                 self.word("*");
             }
             ast::UseTreeKind::Nested(ref items) => {
-                if tree.prefix.segments.is_empty() {
-                    self.word("{");
-                } else {
+                if !tree.prefix.segments.is_empty() {
                     self.print_path(&tree.prefix, false, 0);
-                    self.word("::{");
+                    self.word("::");
+                }
+                if items.is_empty() {
+                    self.word("{}");
+                } else if items.len() == 1 {
+                    self.print_use_tree(&items[0].0);
+                } else {
+                    self.cbox(INDENT_UNIT);
+                    self.word("{");
+                    self.zerobreak();
+                    self.ibox(0);
+                    for use_tree in items.iter().delimited() {
+                        self.print_use_tree(&use_tree.0);
+                        if !use_tree.is_last {
+                            self.word(",");
+                            if let ast::UseTreeKind::Nested(_) = use_tree.0.kind {
+                                self.hardbreak();
+                            } else {
+                                self.space();
+                            }
+                        }
+                    }
+                    self.end();
+                    self.trailing_comma();
+                    self.offset(-INDENT_UNIT);
+                    self.word("}");
+                    self.end();
                 }
-                self.commasep(Inconsistent, &items, |this, &(ref tree, _)| {
-                    this.print_use_tree(tree)
-                });
-                self.word("}");
             }
         }
     }

compiler/rustc_error_codes/src/error_codes.rs

@@ -97,6 +97,7 @@ E0184: include_str!("./error_codes/E0184.md"),
 E0185: include_str!("./error_codes/E0185.md"),
 E0186: include_str!("./error_codes/E0186.md"),
 E0191: include_str!("./error_codes/E0191.md"),
+E0192: include_str!("./error_codes/E0192.md"),
 E0193: include_str!("./error_codes/E0193.md"),
 E0195: include_str!("./error_codes/E0195.md"),
 E0197: include_str!("./error_codes/E0197.md"),
@@ -522,7 +523,6 @@ E0787: include_str!("./error_codes/E0787.md"),
 //  E0188, // can not cast an immutable reference to a mutable pointer
 //  E0189, // deprecated: can only cast a boxed pointer to a boxed object
 //  E0190, // deprecated: can only cast a &-pointer to an &-object
-//  E0192, // negative impl only applicable to auto traits
 //  E0194, // merged into E0403
 //  E0196, // cannot determine a type for this closure
     E0208,

compiler/rustc_error_codes/src/error_codes/E0192.md

@@ -1,15 +1,17 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 A negative impl was added on a trait implementation.
 
 Erroneous code example:
 
-```compile_fail,E0192
+```compile_fail
 trait Trait {
     type Bar;
 }
 
 struct Foo;
 
-impl !Trait for Foo { } //~ ERROR E0192
+impl !Trait for Foo { } //~ ERROR
 
 fn main() {}
 ```