fix: correct some type alias issues

rust-lang · Nov 18, 2021 · 2c442cc · 2c442cc
1 parent 0023abf
commit 2c442cc
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Showing 2 changed files with 32 additions and 25 deletions.
diff --git a/src/items.rs b/src/items.rs
@@ -28,6 28,7 @@ use crate::shape::{Indent, Shape};
 use crate::source_map::{LineRangeUtils, SpanUtils};
 use crate::spanned::Spanned;
 use crate::stmt::Stmt;
 use crate::types::opaque_ty;
 use crate::utils::*;
 use crate::vertical::rewrite_with_alignment;
 use crate::visitor::FmtVisitor;
@@ -581,13 582,10 @@ impl<'a> FmtVisitor<'a> {
  if self.get_context().config.reorder_impl_items() {
  type TyOpt = Option<ptr::P<ast::Ty>>;
  use crate::ast::AssocItemKind::*;
- let is_type = |ty: &TyOpt| {
- ty.as_ref()
- .map_or(true, |t| !matches!(t.kind, ast::TyKind::ImplTrait(..)))
- };
- let is_opaque = |ty: &TyOpt| !is_type(ty);
- let both_type = |left: &TyOpt, right: &TyOpt| is_type(left) && is_type(right);
- let both_opaque = |left: &TyOpt, right: &TyOpt| is_opaque(left) && is_opaque(right);
  let is_type = |ty: &TyOpt| opaque_ty(ty).is_none();
  let is_opaque = |ty: &TyOpt| opaque_ty(ty).is_some();
  let both_type = |l: &TyOpt, r: &TyOpt| is_type(l) && is_type(r);
  let both_opaque = |l: &TyOpt, r: &TyOpt| is_opaque(l) && is_opaque(r);
  let need_empty_line = |a: &ast::AssocItemKind, b: &ast::AssocItemKind| match (a, b) {
  (TyAlias(lty), TyAlias(rty))
  if both_type(&lty.ty, &rty.ty) || both_opaque(&lty.ty, &rty.ty) =>
@@ -1508,43 1506,38 @@ pub(crate) fn rewrite_type_alias<'a, 'b>(
  ref bounds,
  ref ty,
  } = *ty_alias_kind;
- let ty_opt = ty.as_ref().map(|t| &**t);
  let ty_opt = ty.as_ref();
  let (ident, vis) = match visitor_kind {
  Item(i) => (i.ident, &i.vis),
  AssocTraitItem(i) | AssocImplItem(i) => (i.ident, &i.vis),
  ForeignItem(i) => (i.ident, &i.vis),
  };
  let rw_info = &TyAliasRewriteInfo(context, indent, generics, ident, span);
-
  let op_ty = opaque_ty(ty);
  // Type Aliases are formatted slightly differently depending on the context
  // in which they appear, whether they are opaque, and whether they are associated.
  // https://rustc-dev-guide.rust-lang.org/opaque-types-type-alias-impl-trait.html
  // https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/items.md#type-aliases
- match (visitor_kind, ty_opt) {
- (Item(_), None) => {
- let op_ty = OpaqueType { bounds };
- rewrite_ty(rw_info, Some(bounds), Some(&op_ty), vis)
  match (visitor_kind, &op_ty) {
  (Item(_) | AssocTraitItem(_) | ForeignItem(_), Some(ref op_bounds)) => {
  let op = OpaqueType { bounds: op_bounds };
  rewrite_ty(rw_info, Some(bounds), Some(&op), vis)
  }
  (Item(_) | AssocTraitItem(_) | ForeignItem(_), None) => {
  rewrite_ty(rw_info, Some(bounds), ty_opt, vis)
  }
- (Item(_), Some(ty)) => rewrite_ty(rw_info, Some(bounds), Some(&*ty), vis),
  (AssocImplItem(_), _) => {
- let result = if let Some(ast::Ty {
- kind: ast::TyKind::ImplTrait(_, ref bounds),
- ..
- }) = ty_opt
- {
- let op_ty = OpaqueType { bounds };
- rewrite_ty(rw_info, None, Some(&op_ty), &DEFAULT_VISIBILITY)
  let result = if let Some(ref op_bounds) = op_ty {
  let op = OpaqueType { bounds: op_bounds };
  rewrite_ty(rw_info, Some(bounds), Some(&op), &DEFAULT_VISIBILITY)
  } else {
- rewrite_ty(rw_info, None, ty.as_ref(), vis)
  rewrite_ty(rw_info, Some(bounds), ty_opt, vis)
  }?;
  match defaultness {
  ast::Defaultness::Default(..) => Some(format!("default {}", result)),
  _ => Some(result),
  }
  }
- (AssocTraitItem(_), _) | (ForeignItem(_), _) => {
- rewrite_ty(rw_info, Some(bounds), ty.as_ref(), vis)
- }
  }
 }
 
@@ -1867,6 1860,12 @@ fn rewrite_static(
  Some(format!("{}{};", prefix, ty_str))
  }
 }
 
 // FIXME(calebcartwright) - This is a hack around a bug in the handling of TyKind::ImplTrait.
 // This should be removed once that bug is resolved, with the type alias formatting using the
 // defined Ty for the RHS directly.
 // https://github.com/rust-lang/rustfmt/issues/4373
 // https://github.com/rust-lang/rustfmt/issues/5027
 struct OpaqueType<'a> {
  bounds: &'a ast::GenericBounds,
 }

diff --git a/src/types.rs b/src/types.rs
@@ -2,6 2,7 @@ use std::iter::ExactSizeIterator;
 use std::ops::Deref;
 
 use rustc_ast::ast::{self, FnRetTy, Mutability};
 use rustc_ast::ptr;
 use rustc_span::{symbol::kw, BytePos, Pos, Span};
 
 use crate::comment::{combine_strs_with_missing_comments, contains_comment};
@@ -1031,6 1032,13 @@ fn join_bounds_inner(
  }
 }
 
 pub(crate) fn opaque_ty(ty: &Option<ptr::P<ast::Ty>>) -> Option<&ast::GenericBounds> {
  ty.as_ref().and_then(|t| match &t.kind {
  ast::TyKind::ImplTrait(_, bounds) => Some(bounds),
  _ => None,
  })
 }
 
 pub(crate) fn can_be_overflowed_type(
  context: &RewriteContext<'_>,
  ty: &ast::Ty,