Rollup merge of rust-lang#88775 - pnkfelix:revert-anon-union-parsing, r=davidtwco

Revert anon union parsing

Revert PR rust-lang#84571 and rust-lang#85515, which implemented anonymous union parsing in a manner that broke the context-sensitivity for the `union` keyword and thus broke stable Rust code.

Fix rust-lang#88583.

Author: Manishearth

src/items.rs

@@ -6,7 +6,7 @@ use std::cmp::{max, min, Ordering};
 use regex::Regex;
 use rustc_ast::visit;
 use rustc_ast::{ast, ptr};
-use rustc_span::{symbol, BytePos, Span};
+use rustc_span::{symbol, BytePos, Span, DUMMY_SP};
 
 use crate::attr::filter_inline_attrs;
 use crate::comment::{
@@ -31,7 +31,12 @@ use crate::stmt::Stmt;
 use crate::utils::*;
 use crate::vertical::rewrite_with_alignment;
 use crate::visitor::FmtVisitor;
-use crate::DEFAULT_VISIBILITY;
+
+const DEFAULT_VISIBILITY: ast::Visibility = ast::Visibility {
+    kind: ast::VisibilityKind::Inherited,
+    span: DUMMY_SP,
+    tokens: None,
+};
 
 fn type_annotation_separator(config: &Config) -> &str {
     colon_spaces(config)
@@ -972,7 +977,7 @@ impl<'a> StructParts<'a> {
         format_header(context, self.prefix, self.ident, self.vis, offset)
     }
 
-    pub(crate) fn from_variant(variant: &'a ast::Variant) -> Self {
+    fn from_variant(variant: &'a ast::Variant) -> Self {
         StructParts {
             prefix: "",
             ident: variant.ident,

src/lib.rs

@@ -32,7 +32,7 @@ use std::path::PathBuf;
 use std::rc::Rc;
 
 use rustc_ast::ast;
-use rustc_span::{symbol, DUMMY_SP};
+use rustc_span::symbol;
 use thiserror::Error;
 
 use crate::comment::LineClasses;
@@ -96,11 +96,6 @@ mod types;
 mod vertical;
 pub(crate) mod visitor;
 
-const DEFAULT_VISIBILITY: ast::Visibility = ast::Visibility {
-    kind: ast::VisibilityKind::Inherited,
-    span: DUMMY_SP,
-    tokens: None,
-};
 /// The various errors that can occur during formatting. Note that not all of
 /// these can currently be propagated to clients.
 #[derive(Error, Debug)]

src/types.rs

@@ -1,15 +1,15 @@
 use std::iter::ExactSizeIterator;
 use std::ops::Deref;
 
-use rustc_ast::ast::{self, AttrVec, FnRetTy, Mutability};
-use rustc_span::{symbol::kw, symbol::Ident, BytePos, Pos, Span};
+use rustc_ast::ast::{self, FnRetTy, Mutability};
+use rustc_span::{symbol::kw, BytePos, Pos, Span};
 
+use crate::comment::{combine_strs_with_missing_comments, contains_comment};
 use crate::config::lists::*;
 use crate::config::{IndentStyle, TypeDensity, Version};
 use crate::expr::{
     format_expr, rewrite_assign_rhs, rewrite_call, rewrite_tuple, rewrite_unary_prefix, ExprType,
 };
-use crate::items::StructParts;
 use crate::lists::{
     definitive_tactic, itemize_list, write_list, ListFormatting, ListItem, Separator,
 };
@@ -24,11 +24,6 @@ use crate::utils::{
     colon_spaces, extra_offset, first_line_width, format_extern, format_mutability,
     last_line_extendable, last_line_width, mk_sp, rewrite_ident,
 };
-use crate::DEFAULT_VISIBILITY;
-use crate::{
-    comment::{combine_strs_with_missing_comments, contains_comment},
-    items::format_struct_struct,
-};
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub(crate) enum PathContext {
@@ -769,54 +764,6 @@ impl Rewrite for ast::Ty {
             ast::TyKind::Tup(ref items) => {
                 rewrite_tuple(context, items.iter(), self.span, shape, items.len() == 1)
             }
-            ast::TyKind::AnonymousStruct(ref fields, recovered) => {
-                let ident = Ident::new(
-                    kw::Struct,
-                    mk_sp(self.span.lo(), self.span.lo() + BytePos(6)),
-                );
-                let data = ast::VariantData::Struct(fields.clone(), recovered);
-                let variant = ast::Variant {
-                    attrs: AttrVec::new(),
-                    id: self.id,
-                    span: self.span,
-                    vis: DEFAULT_VISIBILITY,
-                    ident,
-                    data,
-                    disr_expr: None,
-                    is_placeholder: false,
-                };
-                format_struct_struct(
-                    &context,
-                    &StructParts::from_variant(&variant),
-                    fields,
-                    shape.indent,
-                    None,
-                )
-            }
-            ast::TyKind::AnonymousUnion(ref fields, recovered) => {
-                let ident = Ident::new(
-                    kw::Union,
-                    mk_sp(self.span.lo(), self.span.lo() + BytePos(5)),
-                );
-                let data = ast::VariantData::Struct(fields.clone(), recovered);
-                let variant = ast::Variant {
-                    attrs: AttrVec::new(),
-                    id: self.id,
-                    span: self.span,
-                    vis: DEFAULT_VISIBILITY,
-                    ident,
-                    data,
-                    disr_expr: None,
-                    is_placeholder: false,
-                };
-                format_struct_struct(
-                    &context,
-                    &StructParts::from_variant(&variant),
-                    fields,
-                    shape.indent,
-                    None,
-                )
-            }
             ast::TyKind::Path(ref q_self, ref path) => {
                 rewrite_path(context, PathContext::Type, q_self.as_ref(), path, shape)
             }