Auto merge of #118395 - compiler-errors:rollup-c8yqlmw, r=compiler-errors

Rollup of 9 pull requests

Successful merges:

 - #111133 (Detect Python-like slicing and suggest how to fix)
 - #114708 (Allow setting `rla` labels via `rustbot`)
 - #117526 (Account for `!` arm in tail `match` expr)
 - #118172 (Add `pretty_terminator` to pretty stable-mir)
 - #118202 (Added linker_arg(s) Linker trait methods for link-arg to be prefixed "-Wl," for cc-like linker args and not verbatim)
 - #118374 (QueryContext: rename try_collect_active_jobs -> collect_active_jobs, change return type from Option<QueryMap> to QueryMap)
 - #118381 (rustc_span: Use correct edit distance start length for suggestions)
 - #118382 (Address unused tuple struct fields in the compiler)
 - #118384 (Address unused tuple struct fields in rustdoc)

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

1 files changed, 28 insertions, 11 deletions

diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs
index 5316dde6096..620ba4a3cb3 100644
--- a/compiler/rustc_parse/src/parser/stmt.rs
+++ b/compiler/rustc_parse/src/parser/stmt.rs
@@ -567,20 +567,37 @@ impl<'a> Parser<'a> {
                         snapshot.recover_diff_marker();
                     }
                     if self.token == token::Colon {
-                        // if next token is following a colon, it's likely a path
-                        // and we can suggest a path separator
-                        self.bump();
-                        if self.token.span.lo() == self.prev_token.span.hi() {
+                        // if a previous and next token of the current one is
+                        // integer literal (e.g. `1:42`), it's likely a range
+                        // expression for Pythonistas and we can suggest so.
+                        if self.prev_token.is_integer_lit()
+                            && self.may_recover()
+                            && self.look_ahead(1, |token| token.is_integer_lit())
+                        {
+                            // FIXME(hkmatsumoto): Might be better to trigger
+                            // this only when parsing an index expression.
                             err.span_suggestion_verbose(
-                                self.prev_token.span,
-                                "maybe write a path separator here",
-                                "::",
+                                self.token.span,
+                                "you might have meant a range expression",
+                                "..",
                                 Applicability::MaybeIncorrect,
                             );
-                        }
-                        if self.sess.unstable_features.is_nightly_build() {
-                            // FIXME(Nilstrieb): Remove this again after a few months.
-                            err.note("type ascription syntax has been removed, see issue #101728 <https://github.com/rust-lang/rust/issues/101728>");
+                        } else {
+                            // if next token is following a colon, it's likely a path
+                            // and we can suggest a path separator
+                            self.bump();
+                            if self.token.span.lo() == self.prev_token.span.hi() {
+                                err.span_suggestion_verbose(
+                                    self.prev_token.span,
+                                    "maybe write a path separator here",
+                                    "::",
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
+                            if self.sess.unstable_features.is_nightly_build() {
+                                // FIXME(Nilstrieb): Remove this again after a few months.
+                                err.note("type ascription syntax has been removed, see issue #101728 <https://github.com/rust-lang/rust/issues/101728>");
+                            }
                         }
                     }