Auto merge of #88824 - Manishearth:rollup-7bzk9h6, r=Manishearth

Rollup of 15 pull requests

Successful merges:

 - #85200 (Ignore derived Clone and Debug implementations during dead code analysis)
 - #86165 (Add proc_macro::Span::{before, after}.)
 - #87088 (Fix stray notes when the source code is not available)
 - #87441 (Emit suggestion when passing byte literal to format macro)
 - #88546 (Emit proper errors when on missing closure braces)
 - #88578 (fix(rustc): suggest `items` be borrowed in `for i in items[x..]`)
 - #88632 (Fix issues with Markdown summary options)
 - #88639 (rustdoc: Fix ICE with `doc(hidden)` on tuple variant fields)
 - #88667 (Tweak `write_fmt` doc.)
 - #88720 (Rustdoc coverage fields count)
 - #88732 (RustWrapper: avoid deleted unclear attribute methods)
 - #88742 (Fix table in docblocks)
 - #88776 (Workaround blink/chromium grid layout limitation of 1000 rows)
 - #88807 (Fix typo in docs for iterators)
 - #88812 (Fix typo `option` -> `options`.)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -218,7 +218,19 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             );
                             if self.fn_self_span_reported.insert(fn_span) {
                                 err.span_note(
-                                    self_arg.span,
+                                    // Check whether the source is accessible
+                                    if self
+                                        .infcx
+                                        .tcx
+                                        .sess
+                                        .source_map()
+                                        .span_to_snippet(self_arg.span)
+                                        .is_ok()
+                                    {
+                                        self_arg.span
+                                    } else {
+                                        fn_call_span
+                                    },
                                     "calling this operator moves the left-hand side",
                                 );
                             }
@@ -429,7 +441,10 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     deref_target_ty
                 ));
 
-                err.span_note(deref_target, "deref defined here");
+                // Check first whether the source is accessible (issue #87060)
+                if self.infcx.tcx.sess.source_map().span_to_snippet(deref_target).is_ok() {
+                    err.span_note(deref_target, "deref defined here");
+                }
             }
 
             if let Some((_, mut old_err)) =

compiler/rustc_builtin_macros/src/asm.rs

@@ -510,7 +510,7 @@ fn expand_preparsed_asm(ecx: &mut ExtCtxt<'_>, args: AsmArgs) -> Option<ast::Inl
             match expr_to_spanned_string(ecx, template_expr, msg) {
                 Ok(template_part) => template_part,
                 Err(err) => {
-                    if let Some(mut err) = err {
+                    if let Some((mut err, _)) = err {
                         err.emit();
                     }
                     return None;

compiler/rustc_builtin_macros/src/format.rs

@@ -964,17 +964,19 @@ pub fn expand_preparsed_format_args(
         }
         Ok(fmt) => fmt,
         Err(err) => {
-            if let Some(mut err) = err {
+            if let Some((mut err, suggested)) = err {
                 let sugg_fmt = match args.len() {
                     0 => "{}".to_string(),
                     _ => format!("{}{{}}", "{} ".repeat(args.len())),
                 };
-                err.span_suggestion(
-                    fmt_sp.shrink_to_lo(),
-                    "you might be missing a string literal to format with",
-                    format!("\"{}\", ", sugg_fmt),
-                    Applicability::MaybeIncorrect,
-                );
+                if !suggested {
+                    err.span_suggestion(
+                        fmt_sp.shrink_to_lo(),
+                        "you might be missing a string literal to format with",
+                        format!("\"{}\", ", sugg_fmt),
+                        Applicability::MaybeIncorrect,
+                    );
+                }
                 err.emit();
             }
             return DummyResult::raw_expr(sp, true);

compiler/rustc_expand/src/base.rs

@@ -10,7 +10,7 @@ use rustc_ast::{self as ast, AstLike, Attribute, Item, NodeId, PatKind};
 use rustc_attr::{self as attr, Deprecation, Stability};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::{self, Lrc};
-use rustc_errors::{DiagnosticBuilder, ErrorReported};
+use rustc_errors::{Applicability, DiagnosticBuilder, ErrorReported};
 use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
 use rustc_lint_defs::BuiltinLintDiagnostics;
 use rustc_parse::{self, nt_to_tokenstream, parser, MACRO_ARGUMENTS};
@@ -1136,36 +1136,51 @@ impl<'a> ExtCtxt<'a> {
 }
 
 /// Extracts a string literal from the macro expanded version of `expr`,
-/// emitting `err_msg` if `expr` is not a string literal. This does not stop
-/// compilation on error, merely emits a non-fatal error and returns `None`.
+/// returning a diagnostic error of `err_msg` if `expr` is not a string literal.
+/// The returned bool indicates whether an applicable suggestion has already been
+/// added to the diagnostic to avoid emitting multiple suggestions. `Err(None)`
+/// indicates that an ast error was encountered.
 pub fn expr_to_spanned_string<'a>(
     cx: &'a mut ExtCtxt<'_>,
     expr: P<ast::Expr>,
     err_msg: &str,
-) -> Result<(Symbol, ast::StrStyle, Span), Option<DiagnosticBuilder<'a>>> {
+) -> Result<(Symbol, ast::StrStyle, Span), Option<(DiagnosticBuilder<'a>, bool)>> {
     // Perform eager expansion on the expression.
     // We want to be able to handle e.g., `concat!("foo", "bar")`.
     let expr = cx.expander().fully_expand_fragment(AstFragment::Expr(expr)).make_expr();
 
     Err(match expr.kind {
         ast::ExprKind::Lit(ref l) => match l.kind {
             ast::LitKind::Str(s, style) => return Ok((s, style, expr.span)),
+            ast::LitKind::ByteStr(_) => {
+                let mut err = cx.struct_span_err(l.span, err_msg);
+                err.span_suggestion(
+                    expr.span.shrink_to_lo(),
+                    "consider removing the leading `b`",
+                    String::new(),
+                    Applicability::MaybeIncorrect,
+                );
+                Some((err, true))
+            }
             ast::LitKind::Err(_) => None,
-            _ => Some(cx.struct_span_err(l.span, err_msg)),
+            _ => Some((cx.struct_span_err(l.span, err_msg), false)),
         },
         ast::ExprKind::Err => None,
-        _ => Some(cx.struct_span_err(expr.span, err_msg)),
+        _ => Some((cx.struct_span_err(expr.span, err_msg), false)),
     })
 }
 
+/// Extracts a string literal from the macro expanded version of `expr`,
+/// emitting `err_msg` if `expr` is not a string literal. This does not stop
+/// compilation on error, merely emits a non-fatal error and returns `None`.
 pub fn expr_to_string(
     cx: &mut ExtCtxt<'_>,
     expr: P<ast::Expr>,
     err_msg: &str,
 ) -> Option<(Symbol, ast::StrStyle)> {
     expr_to_spanned_string(cx, expr, err_msg)
         .map_err(|err| {
-            err.map(|mut err| {
+            err.map(|(mut err, _)| {
                 err.emit();
             })
         })

compiler/rustc_expand/src/proc_macro_server.rs

@@ -758,6 +758,12 @@ impl server::Span for Rustc<'_> {
         let loc = self.sess.source_map().lookup_char_pos(span.hi());
         LineColumn { line: loc.line, column: loc.col.to_usize() }
     }
+    fn before(&mut self, span: Self::Span) -> Self::Span {
+        span.shrink_to_lo()
+    }
+    fn after(&mut self, span: Self::Span) -> Self::Span {
+        span.shrink_to_hi()
+    }
     fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {
         let self_loc = self.sess.source_map().lookup_char_pos(first.lo());
         let other_loc = self.sess.source_map().lookup_char_pos(second.lo());

compiler/rustc_feature/src/accepted.rs

@@ -16,7 +16,6 @@ macro_rules! declare_features {
                     since: $ver,
                     issue: to_nonzero($issue),
                     edition: None,
-                    description: concat!($($doc,)*),
                 }
             ),+
         ];

compiler/rustc_feature/src/active.rs

@@ -37,7 +37,6 @@ macro_rules! declare_features {
                     since: $ver,
                     issue: to_nonzero($issue),
                     edition: $edition,
-                    description: concat!($($doc,)*),
                 }
             ),+];
 

compiler/rustc_feature/src/builtin_attrs.rs

@@ -453,6 +453,9 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     ),
     // Enumerates "identity-like" conversion methods to suggest on type mismatch.
     rustc_attr!(rustc_conversion_suggestion, Normal, template!(Word), INTERNAL_UNSTABLE),
+    // Prevents field reads in the marked trait or method to be considered
+    // during dead code analysis.
+    rustc_attr!(rustc_trivial_field_reads, Normal, template!(Word), INTERNAL_UNSTABLE),
 
     // ==========================================================================
     // Internal attributes, Const related:

compiler/rustc_feature/src/lib.rs

@@ -51,7 +51,6 @@ pub struct Feature {
     pub since: &'static str,
     issue: Option<NonZeroU32>,
     pub edition: Option<Edition>,
-    description: &'static str,
 }
 
 #[derive(Copy, Clone, Debug)]

compiler/rustc_feature/src/removed.rs

@@ -16,7 +16,6 @@ macro_rules! declare_features {
                     since: $ver,
                     issue: to_nonzero($issue),
                     edition: None,
-                    description: concat!($($doc,)*),
                 }
             ),+
         ];
@@ -34,7 +33,6 @@ macro_rules! declare_features {
                     since: $ver,
                     issue: to_nonzero($issue),
                     edition: None,
-                    description: concat!($($doc,)*),
                 }
             ),+
         ];