.unwrap() less on .span_to_snippet()

Author: Centril

src/librustc_parse/parser/stmt.rs

@@ -165,9 +165,9 @@ impl<'a> Parser<'a> {
  // Rewind to before attempting to parse the type and continue parsing.
  let parser_snapshot_after_type = self.clone();
  mem::replace(self, parser_snapshot_before_type);
-
- let snippet = self.span_to_snippet(pat.span).unwrap();
- err.span_label(pat.span, format!("while parsing the type for `{}`", snippet));
+ if let Ok(snip) = self.span_to_snippet(pat.span) {
+  err.span_label(pat.span, format!("while parsing the type for `{}`", snip));
+ }
  (Some((parser_snapshot_after_type, colon_sp, err)), None)
  }
  }

src/librustc_trait_selection/traits/error_reporting/suggestions.rs

@@ -732,12 +732,13 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
  true
  };
 
+ let sm = self.tcx.sess.source_map();
  let (snippet, last_ty) =
  if let (true, hir::TyKind::TraitObject(..), Ok(snippet), true, Some(last_ty)) = (
  // Verify that we're dealing with a return `dyn Trait`
  ret_ty.span.overlaps(span),
  &ret_ty.kind,
- self.tcx.sess.source_map().span_to_snippet(ret_ty.span),
+ sm.span_to_snippet(ret_ty.span),
  // If any of the return types does not conform to the trait, then we can't
  // suggest `impl Trait` nor trait objects, it is a type mismatch error.
  all_returns_conform_to_trait,
@@ -775,26 +776,23 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
  if is_object_safe {
  // Suggest `-> Box<dyn Trait>` and `Box::new(returned_value)`.
  // Get all the return values and collect their span and suggestion.
- let mut suggestions = visitor
+ if let Some(mut suggestions) = visitor
  .returns
  .iter()
  .map(|expr| {
- (
- expr.span,
- format!(
- "Box::new({})",
- self.tcx.sess.source_map().span_to_snippet(expr.span).unwrap()
- ),
- )
+ let snip = sm.span_to_snippet(expr.span).ok()?;
+ Some((expr.span, format!("Box::new({})", snip)))
  })
- .collect::<Vec<_>>();
- // Add the suggestion for the return type.
- suggestions.push((ret_ty.span, format!("Box<dyn {}>", trait_obj)));
- err.multipart_suggestion(
- "return a boxed trait object instead",
- suggestions,
- Applicability::MaybeIncorrect,
- );
+ .collect::<Option<Vec<_>>>()
+ {
+ // Add the suggestion for the return type.
+ suggestions.push((ret_ty.span, format!("Box<dyn {}>", trait_obj)));
+ err.multipart_suggestion(
+ "return a boxed trait object instead",
+ suggestions,
+ Applicability::MaybeIncorrect,
+ );
+ }
  } else {
  // This is currently not possible to trigger because E0038 takes precedence, but
  // leave it in for completeness in case anything changes in an earlier stage.