Auto merge of rust-lang#76231 - tmandry:rollup-ilvs9fq, r=tmandry

Rollup of 14 pull requests

Successful merges:

 - rust-lang#74880 (Add trailing comma support to matches macro)
 - rust-lang#76074 (Add new `-Z dump-mir-spanview` option)
 - rust-lang#76088 (Add more examples to lexicographic cmp on Iterators.)
 - rust-lang#76099 (Add info about `!` and `impl Trait`)
 - rust-lang#76126 (Use "Fira Sans" for crate list font)
 - rust-lang#76132 (Factor out StmtKind::MacCall fields into `MacCallStmt` struct)
 - rust-lang#76143 (Give a better error message for duplicate built-in macros)
 - rust-lang#76158 (Stabilise link-self-contained option)
 - rust-lang#76201 (Move to intra-doc links for library/core/src/panic.rs)
 - rust-lang#76206 (Make all methods of `std::net::Ipv6Addr` const)
 - rust-lang#76207 (# Move to intra-doc links for library/core/src/clone.rs)
 - rust-lang#76212 (Document lint missing_doc_code_examples is nightly-only)
 - rust-lang#76218 (lexer: Tiny improvement to shebang detection)
 - rust-lang#76221 (Clean up header in `iter` docs for `for` loops)

Failed merges:

r? @ghost

compiler/rustc_ast/src/ast.rs

@@ -922,9 +922,13 @@ impl Stmt {
     pub fn add_trailing_semicolon(mut self) -> Self {
         self.kind = match self.kind {
             StmtKind::Expr(expr) => StmtKind::Semi(expr),
-            StmtKind::MacCall(mac) => StmtKind::MacCall(
-                mac.map(|(mac, _style, attrs)| (mac, MacStmtStyle::Semicolon, attrs)),
-            ),
+            StmtKind::MacCall(mac) => {
+                StmtKind::MacCall(mac.map(|MacCallStmt { mac, style: _, attrs }| MacCallStmt {
+                    mac,
+                    style: MacStmtStyle::Semicolon,
+                    attrs,
+                }))
+            }
             kind => kind,
         };
         self
@@ -958,7 +962,14 @@ pub enum StmtKind {
     /// Just a trailing semi-colon.
     Empty,
     /// Macro.
-    MacCall(P<(MacCall, MacStmtStyle, AttrVec)>),
+    MacCall(P<MacCallStmt>),
+}
+
+#[derive(Clone, Encodable, Decodable, Debug)]
+pub struct MacCallStmt {
+    pub mac: MacCall,
+    pub style: MacStmtStyle,
+    pub attrs: AttrVec,
 }
 
 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug)]

compiler/rustc_ast/src/attr/mod.rs

@@ -16,7 +16,6 @@ use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::Span;
 
 use std::iter;
-use std::ops::DerefMut;
 
 pub struct MarkedAttrs(GrowableBitSet<AttrId>);
 
@@ -634,10 +633,7 @@ impl HasAttrs for StmtKind {
             StmtKind::Local(ref local) => local.attrs(),
             StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
             StmtKind::Empty | StmtKind::Item(..) => &[],
-            StmtKind::MacCall(ref mac) => {
-                let (_, _, ref attrs) = **mac;
-                attrs.attrs()
-            }
+            StmtKind::MacCall(ref mac) => mac.attrs.attrs(),
         }
     }
 
@@ -647,8 +643,7 @@ impl HasAttrs for StmtKind {
             StmtKind::Expr(expr) | StmtKind::Semi(expr) => expr.visit_attrs(f),
             StmtKind::Empty | StmtKind::Item(..) => {}
             StmtKind::MacCall(mac) => {
-                let (_mac, _style, attrs) = mac.deref_mut();
-                attrs.visit_attrs(f);
+                mac.attrs.visit_attrs(f);
             }
         }
     }

compiler/rustc_ast/src/mut_visit.rs

@@ -1305,7 +1305,7 @@ pub fn noop_flat_map_stmt_kind<T: MutVisitor>(
         StmtKind::Semi(expr) => vis.filter_map_expr(expr).into_iter().map(StmtKind::Semi).collect(),
         StmtKind::Empty => smallvec![StmtKind::Empty],
         StmtKind::MacCall(mut mac) => {
-            let (mac_, _semi, attrs) = mac.deref_mut();
+            let MacCallStmt { mac: mac_, style: _, attrs } = mac.deref_mut();
             vis.visit_mac(mac_);
             visit_thin_attrs(attrs, vis);
             smallvec![StmtKind::MacCall(mac)]

compiler/rustc_ast/src/visit.rs

@@ -692,7 +692,7 @@ pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) {
         StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => visitor.visit_expr(expr),
         StmtKind::Empty => {}
         StmtKind::MacCall(ref mac) => {
-            let (ref mac, _, ref attrs) = **mac;
+            let MacCallStmt { ref mac, style: _, ref attrs } = **mac;
             visitor.visit_mac(mac);
             for attr in attrs.iter() {
                 visitor.visit_attribute(attr);

compiler/rustc_ast_pretty/src/pprust.rs

@@ -1507,11 +1507,10 @@ impl<'a> State<'a> {
                 self.s.word(";");
             }
             ast::StmtKind::MacCall(ref mac) => {
-                let (ref mac, style, ref attrs) = **mac;
                 self.space_if_not_bol();
-                self.print_outer_attributes(attrs);
-                self.print_mac(mac);
-                if style == ast::MacStmtStyle::Semicolon {
+                self.print_outer_attributes(&mac.attrs);
+                self.print_mac(&mac.mac);
+                if mac.style == ast::MacStmtStyle::Semicolon {
                     self.s.word(";");
                 }
             }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1084,7 +1084,7 @@ fn get_crt_libs_path(sess: &Session) -> Option<PathBuf> {
 
 fn get_object_file_path(sess: &Session, name: &str, self_contained: bool) -> PathBuf {
     // prefer system {,dll}crt2.o libs, see get_crt_libs_path comment for more details
-    if sess.opts.debugging_opts.link_self_contained.is_none()
+    if sess.opts.cg.link_self_contained.is_none()
         && sess.target.target.llvm_target.contains("windows-gnu")
     {
         if let Some(compiler_libs_path) = get_crt_libs_path(sess) {
@@ -1289,7 +1289,7 @@ fn link_output_kind(sess: &Session, crate_type: CrateType) -> LinkOutputKind {
 /// Whether we link to our own CRT objects instead of relying on gcc to pull them.
 /// We only provide such support for a very limited number of targets.
 fn crt_objects_fallback(sess: &Session, crate_type: CrateType) -> bool {
-    if let Some(self_contained) = sess.opts.debugging_opts.link_self_contained {
+    if let Some(self_contained) = sess.opts.cg.link_self_contained {
         return self_contained;
     }
 
@@ -1499,7 +1499,7 @@ fn link_local_crate_native_libs_and_dependent_crate_libs<'a, B: ArchiveBuilder<'
 /// Add sysroot and other globally set directories to the directory search list.
 fn add_library_search_dirs(cmd: &mut dyn Linker, sess: &Session, self_contained: bool) {
     // Prefer system mingw-w64 libs, see get_crt_libs_path comment for more details.
-    if sess.opts.debugging_opts.link_self_contained.is_none()
+    if sess.opts.cg.link_self_contained.is_none()
         && cfg!(windows)
         && sess.target.target.llvm_target.contains("windows-gnu")
     {

compiler/rustc_error_codes/src/error_codes.rs

@@ -454,6 +454,7 @@ E0768: include_str!("./error_codes/E0768.md"),
 E0769: include_str!("./error_codes/E0769.md"),
 E0770: include_str!("./error_codes/E0770.md"),
 E0771: include_str!("./error_codes/E0771.md"),
+E0773: include_str!("./error_codes/E0773.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard

compiler/rustc_error_codes/src/error_codes/E0773.md

@@ -0,0 +1,38 @@
+A builtin-macro was defined more than once.
+
+Erroneous code example:
+
+```compile_fail,E0773
+#![feature(decl_macro)]
+#![feature(rustc_attrs)]
+
+#[rustc_builtin_macro]
+pub macro test($item:item) {
+    /* compiler built-in */
+}
+
+mod inner {
+    #[rustc_builtin_macro]
+    pub macro test($item:item) {
+        /* compiler built-in */
+    }
+}
+```
+
+To fix the issue, remove the duplicate declaration:
+
+```
+#![feature(decl_macro)]
+#![feature(rustc_attrs)]
+
+#[rustc_builtin_macro]
+pub macro test($item:item) {
+    /* compiler built-in */
+}
+```
+
+In very rare edge cases, this may happen when loading `core` or `std` twice,
+once with `check` metadata and once with `build` metadata.
+For more information, see [#75176].
+
+[#75176]: https://github.com/rust-lang/rust/pull/75176#issuecomment-683234468

compiler/rustc_expand/src/expand.rs

@@ -13,7 +13,7 @@ use rustc_ast::token;
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::visit::{self, AssocCtxt, Visitor};
 use rustc_ast::{self as ast, AttrItem, Block, LitKind, NodeId, PatKind, Path};
-use rustc_ast::{ItemKind, MacArgs, MacStmtStyle, StmtKind};
+use rustc_ast::{ItemKind, MacArgs, MacCallStmt, MacStmtStyle, StmtKind};
 use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, is_builtin_attr, HasAttrs};
 use rustc_data_structures::map_in_place::MapInPlace;
@@ -1363,7 +1363,7 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
         }
 
         if let StmtKind::MacCall(mac) = stmt.kind {
-            let (mac, style, attrs) = mac.into_inner();
+            let MacCallStmt { mac, style, attrs } = mac.into_inner();
             self.check_attributes(&attrs);
             let mut placeholder =
                 self.collect_bang(mac, stmt.span, AstFragmentKind::Stmts).make_stmts();

compiler/rustc_expand/src/placeholders.rs

@@ -92,7 +92,11 @@ pub fn placeholder(
             AstFragment::Ty(P(ast::Ty { id, span, kind: ast::TyKind::MacCall(mac_placeholder()) }))
         }
         AstFragmentKind::Stmts => AstFragment::Stmts(smallvec![{
-            let mac = P((mac_placeholder(), ast::MacStmtStyle::Braces, ast::AttrVec::new()));
+            let mac = P(ast::MacCallStmt {
+                mac: mac_placeholder(),
+                style: ast::MacStmtStyle::Braces,
+                attrs: ast::AttrVec::new(),
+            });
             ast::Stmt { id, span, kind: ast::StmtKind::MacCall(mac) }
         }]),
         AstFragmentKind::Arms => AstFragment::Arms(smallvec![ast::Arm {
@@ -293,7 +297,7 @@ impl<'a, 'b> MutVisitor for PlaceholderExpander<'a, 'b> {
 
     fn flat_map_stmt(&mut self, stmt: ast::Stmt) -> SmallVec<[ast::Stmt; 1]> {
         let (style, mut stmts) = match stmt.kind {
-            ast::StmtKind::MacCall(mac) => (mac.1, self.remove(stmt.id).make_stmts()),
+            ast::StmtKind::MacCall(mac) => (mac.style, self.remove(stmt.id).make_stmts()),
             _ => return noop_flat_map_stmt(stmt, self),
         };
 

compiler/rustc_interface/src/tests.rs

@@ -402,6 +402,7 @@ fn test_codegen_options_tracking_hash() {
     // `link_arg` is omitted because it just forwards to `link_args`.
     untracked!(link_args, vec![String::from("abc"), String::from("def")]);
     untracked!(link_dead_code, Some(true));
+    untracked!(link_self_contained, Some(true));
     untracked!(linker, Some(PathBuf::from("linker")));
     untracked!(linker_flavor, Some(LinkerFlavor::Gcc));
     untracked!(no_stack_check, true);

compiler/rustc_lexer/src/lib.rs

@@ -191,12 +191,16 @@ pub fn strip_shebang(input: &str) -> Option<usize> {
     // For simplicity we consider any line starting with `#!` a shebang,
     // regardless of restrictions put on shebangs by specific platforms.
     if let Some(input_tail) = input.strip_prefix("#!") {
-        // Ok, this is a shebang but if the next non-whitespace token is `[` or maybe
-        // a doc comment (due to `TokenKind::(Line,Block)Comment` ambiguity at lexer level),
+        // Ok, this is a shebang but if the next non-whitespace token is `[`,
         // then it may be valid Rust code, so consider it Rust code.
-        let next_non_whitespace_token = tokenize(input_tail).map(|tok| tok.kind).find(|tok|
-            !matches!(tok, TokenKind::Whitespace | TokenKind::LineComment { .. } | TokenKind::BlockComment { .. })
-        );
+        let next_non_whitespace_token = tokenize(input_tail).map(|tok| tok.kind).find(|tok| {
+            !matches!(
+                tok,
+                TokenKind::Whitespace
+                    | TokenKind::LineComment { doc_style: None }
+                    | TokenKind::BlockComment { doc_style: None, .. }
+            )
+        });
         if next_non_whitespace_token != Some(TokenKind::OpenBracket) {
             // No other choice than to consider this a shebang.
             return Some(2 + input_tail.lines().next().unwrap_or_default().len());

compiler/rustc_mir/src/util/mod.rs

@@ -9,6 +9,7 @@ mod alignment;
 pub mod collect_writes;
 mod graphviz;
 pub(crate) mod pretty;
+pub(crate) mod spanview;
 
 pub use self::aggregate::expand_aggregate;
 pub use self::alignment::is_disaligned;

compiler/rustc_mir/src/util/pretty.rs

@@ -6,6 +6,7 @@ use std::io::{self, Write};
 use std::path::{Path, PathBuf};
 
 use super::graphviz::write_mir_fn_graphviz;
+use super::spanview::write_mir_fn_spanview;
 use crate::transform::MirSource;
 use either::Either;
 use rustc_data_structures::fx::FxHashMap;
@@ -147,6 +148,16 @@ fn dump_matched_mir_node<'tcx, F>(
             write_mir_fn_graphviz(tcx, source.def_id(), body, false, &mut file)?;
         };
     }
+
+    if let Some(spanview) = tcx.sess.opts.debugging_opts.dump_mir_spanview {
+        let _: io::Result<()> = try {
+            let mut file =
+                create_dump_file(tcx, "html", pass_num, pass_name, disambiguator, source)?;
+            if source.def_id().is_local() {
+                write_mir_fn_spanview(tcx, source.def_id(), body, spanview, &mut file)?;
+            }
+        };
+    }
 }
 
 /// Returns the path to the filename where we should dump a given MIR.