Auto merge of #89047 - GuillaumeGomez:rollup-29gmr02, r=GuillaumeGomez

Rollup of 10 pull requests

Successful merges:

 - #86422 (Emit clearer diagnostics for parens around `for` loop heads)
 - #87460 (Point to closure when emitting 'cannot move out' for captured variable)
 - #87566 (Recover invalid assoc type bounds using `==`)
 - #88666 (Improve build command for compiler docs)
 - #88899 (Do not issue E0071 if a type error has already been reported)
 - #88949 (Fix handling of `hir::GenericArg::Infer` in `wrong_number_of_generic_args.rs`)
 - #88953 (Add chown functions to std::os::unix::fs to change the owner and group of files)
 - #88954 (Allow `panic!("{}", computed_str)` in const fn.)
 - #88964 (Add rustdoc version into the help popup)
 - #89012 (Suggest removing `#![feature]` for library features that have been stabilized)

Failed merges:

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

2 files changed, 27 insertions, 20 deletions

diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 4fccfc287fd..708df5e46d4 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -1334,30 +1334,25 @@ impl<'a> Parser<'a> {
     pub(super) fn recover_parens_around_for_head(
         &mut self,
         pat: P<Pat>,
-        expr: &Expr,
         begin_paren: Option<Span>,
     ) -> P<Pat> {
         match (&self.token.kind, begin_paren) {
             (token::CloseDelim(token::Paren), Some(begin_par_sp)) => {
                 self.bump();
 
-                let pat_str = self
-                    // Remove the `(` from the span of the pattern:
-                    .span_to_snippet(pat.span.trim_start(begin_par_sp).unwrap())
-                    .unwrap_or_else(|_| pprust::pat_to_string(&pat));
-
-                self.struct_span_err(self.prev_token.span, "unexpected closing `)`")
-                    .span_label(begin_par_sp, "opening `(`")
-                    .span_suggestion(
-                        begin_par_sp.to(self.prev_token.span),
-                        "remove parenthesis in `for` loop",
-                        format!("{} in {}", pat_str, pprust::expr_to_string(&expr)),
-                        // With e.g. `for (x) in y)` this would replace `(x) in y)`
-                        // with `x) in y)` which is syntactically invalid.
-                        // However, this is prevented before we get here.
-                        Applicability::MachineApplicable,
-                    )
-                    .emit();
+                self.struct_span_err(
+                    MultiSpan::from_spans(vec![begin_par_sp, self.prev_token.span]),
+                    "unexpected parenthesis surrounding `for` loop head",
+                )
+                .multipart_suggestion(
+                    "remove parenthesis in `for` loop",
+                    vec![(begin_par_sp, String::new()), (self.prev_token.span, String::new())],
+                    // With e.g. `for (x) in y)` this would replace `(x) in y)`
+                    // with `x) in y)` which is syntactically invalid.
+                    // However, this is prevented before we get here.
+                    Applicability::MachineApplicable,
+                )
+                .emit();
 
                 // Unwrap `(pat)` into `pat` to avoid the `unused_parens` lint.
                 pat.and_then(|pat| match pat.kind {
@@ -1955,7 +1950,19 @@ impl<'a> Parser<'a> {
         }
         match self.parse_expr_res(Restrictions::CONST_EXPR, None) {
             Ok(expr) => {
-                if token::Comma == self.token.kind || self.token.kind.should_end_const_arg() {
+                // Find a mistake like `MyTrait<Assoc == S::Assoc>`.
+                if token::EqEq == snapshot.token.kind {
+                    err.span_suggestion(
+                        snapshot.token.span,
+                        "if you meant to use an associated type binding, replace `==` with `=`",
+                        "=".to_string(),
+                        Applicability::MaybeIncorrect,
+                    );
+                    let value = self.mk_expr_err(start.to(expr.span));
+                    err.emit();
+                    return Ok(GenericArg::Const(AnonConst { id: ast::DUMMY_NODE_ID, value }));
+                } else if token::Comma == self.token.kind || self.token.kind.should_end_const_arg()
+                {
                     // Avoid the following output by checking that we consumed a full const arg:
                     // help: expressions must be enclosed in braces to be used as const generic
                     //       arguments
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 737f1d9cbb1..d8f9fc9179e 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -2042,7 +2042,7 @@ impl<'a> Parser<'a> {
         self.check_for_for_in_in_typo(self.prev_token.span);
         let expr = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, None)?;
 
-        let pat = self.recover_parens_around_for_head(pat, &expr, begin_paren);
+        let pat = self.recover_parens_around_for_head(pat, begin_paren);
 
         let (iattrs, loop_block) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);