Auto merge of #65495 - Centril:rollup-tguwjt5, r=Centril

Rollup of 8 pull requests

Successful merges:

 - #65237 (Move debug_map assertions after check for err)
 - #65316 (make File::try_clone produce non-inheritable handles on Windows)
 - #65319 (InterpCx: make memory field public)
 - #65461 (Don't recommend ONCE_INIT in std::sync::Once)
 - #65465 (Move syntax::ext to a syntax_expand and refactor some attribute logic)
 - #65475 (add example for type_name)
 - #65478 (fmt::Write is about string slices, not byte slices)
 - #65486 (doc: fix typo in OsStrExt and OsStringExt)

Failed merges:

r? @ghost

13 files changed, 199 insertions, 143 deletions

diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index cb90caab77a..e6b794a6a99 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -2,7 +2,7 @@
 
 use crate::ast;
 use crate::parse::parser::{Parser, emit_unclosed_delims};
-use crate::parse::token::{Nonterminal, TokenKind};
+use crate::parse::token::Nonterminal;
 use crate::tokenstream::{self, TokenStream, TokenTree};
 use crate::print::pprust;
 use crate::sess::ParseSess;
@@ -24,12 +24,10 @@ mod tests;
 
 #[macro_use]
 pub mod parser;
-pub mod attr;
 pub mod lexer;
 pub mod token;
 
 crate mod classify;
-crate mod diagnostics;
 crate mod literal;
 crate mod unescape_error_reporting;
 
@@ -273,30 +271,6 @@ pub fn stream_to_parser_with_base_dir<'a>(
     Parser::new(sess, stream, Some(base_dir), true, false, None)
 }
 
-/// A sequence separator.
-pub struct SeqSep {
-    /// The separator token.
-    pub sep: Option<TokenKind>,
-    /// `true` if a trailing separator is allowed.
-    pub trailing_sep_allowed: bool,
-}
-
-impl SeqSep {
-    pub fn trailing_allowed(t: TokenKind) -> SeqSep {
-        SeqSep {
-            sep: Some(t),
-            trailing_sep_allowed: true,
-        }
-    }
-
-    pub fn none() -> SeqSep {
-        SeqSep {
-            sep: None,
-            trailing_sep_allowed: false,
-        }
-    }
-}
-
 // NOTE(Centril): The following probably shouldn't be here but it acknowledges the
 // fact that architecturally, we are using parsing (read on below to understand why).
 
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 86383761484..9cb410a8ae3 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -1,21 +1,21 @@
+pub mod attr;
 mod expr;
 mod pat;
 mod item;
-pub use item::AliasKind;
 mod module;
-pub use module::{ModulePath, ModulePathSuccess};
 mod ty;
 mod path;
 pub use path::PathStyle;
 mod stmt;
 mod generics;
-use super::diagnostics::Error;
+mod diagnostics;
+use diagnostics::Error;
 
 use crate::ast::{
     self, DUMMY_NODE_ID, AttrStyle, Attribute, CrateSugar, Ident,
     IsAsync, MacDelimiter, Mutability, StrStyle, Visibility, VisibilityKind, Unsafety,
 };
-use crate::parse::{PResult, Directory, DirectoryOwnership, SeqSep};
+use crate::parse::{PResult, Directory, DirectoryOwnership};
 use crate::parse::lexer::UnmatchedBrace;
 use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
 use crate::parse::token::{self, Token, TokenKind, DelimToken};
@@ -44,14 +44,14 @@ bitflags::bitflags! {
 }
 
 #[derive(Clone, Copy, PartialEq, Debug)]
-crate enum SemiColonMode {
+enum SemiColonMode {
     Break,
     Ignore,
     Comma,
 }
 
 #[derive(Clone, Copy, PartialEq, Debug)]
-crate enum BlockMode {
+enum BlockMode {
     Break,
     Ignore,
 }
@@ -124,33 +124,33 @@ pub struct Parser<'a> {
     prev_token_kind: PrevTokenKind,
     restrictions: Restrictions,
     /// Used to determine the path to externally loaded source files.
-    crate directory: Directory<'a>,
+    pub(super) directory: Directory<'a>,
     /// `true` to parse sub-modules in other files.
-    pub recurse_into_file_modules: bool,
+    pub(super) recurse_into_file_modules: bool,
     /// Name of the root module this parser originated from. If `None`, then the
     /// name is not known. This does not change while the parser is descending
     /// into modules, and sub-parsers have new values for this name.
     pub root_module_name: Option<String>,
-    crate expected_tokens: Vec<TokenType>,
+    expected_tokens: Vec<TokenType>,
     token_cursor: TokenCursor,
     desugar_doc_comments: bool,
     /// `true` we should configure out of line modules as we parse.
-    pub cfg_mods: bool,
+    cfg_mods: bool,
     /// This field is used to keep track of how many left angle brackets we have seen. This is
     /// required in order to detect extra leading left angle brackets (`<` characters) and error
     /// appropriately.
     ///
     /// See the comments in the `parse_path_segment` function for more details.
-    crate unmatched_angle_bracket_count: u32,
-    crate max_angle_bracket_count: u32,
+    unmatched_angle_bracket_count: u32,
+    max_angle_bracket_count: u32,
     /// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery
     /// it gets removed from here. Every entry left at the end gets emitted as an independent
     /// error.
-    crate unclosed_delims: Vec<UnmatchedBrace>,
-    crate last_unexpected_token_span: Option<Span>,
-    crate last_type_ascription: Option<(Span, bool /* likely path typo */)>,
+    pub(super) unclosed_delims: Vec<UnmatchedBrace>,
+    last_unexpected_token_span: Option<Span>,
+    pub last_type_ascription: Option<(Span, bool /* likely path typo */)>,
     /// If present, this `Parser` is not parsing Rust code but rather a macro call.
-    crate subparser_name: Option<&'static str>,
+    subparser_name: Option<&'static str>,
 }
 
 impl<'a> Drop for Parser<'a> {
@@ -194,7 +194,7 @@ struct TokenCursorFrame {
 /// You can find some more example usage of this in the `collect_tokens` method
 /// on the parser.
 #[derive(Clone)]
-crate enum LastToken {
+enum LastToken {
     Collecting(Vec<TreeAndJoint>),
     Was(Option<TreeAndJoint>),
 }
@@ -297,7 +297,7 @@ impl TokenCursor {
 }
 
 #[derive(Clone, PartialEq)]
-crate enum TokenType {
+enum TokenType {
     Token(TokenKind),
     Keyword(Symbol),
     Operator,
@@ -309,7 +309,7 @@ crate enum TokenType {
 }
 
 impl TokenType {
-    crate fn to_string(&self) -> String {
+    fn to_string(&self) -> String {
         match *self {
             TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)),
             TokenType::Keyword(kw) => format!("`{}`", kw),
@@ -324,11 +324,35 @@ impl TokenType {
 }
 
 #[derive(Copy, Clone, Debug)]
-crate enum TokenExpectType {
+enum TokenExpectType {
     Expect,
     NoExpect,
 }
 
+/// A sequence separator.
+struct SeqSep {
+    /// The separator token.
+    sep: Option<TokenKind>,
+    /// `true` if a trailing separator is allowed.
+    trailing_sep_allowed: bool,
+}
+
+impl SeqSep {
+    fn trailing_allowed(t: TokenKind) -> SeqSep {
+        SeqSep {
+            sep: Some(t),
+            trailing_sep_allowed: true,
+        }
+    }
+
+    fn none() -> SeqSep {
+        SeqSep {
+            sep: None,
+            trailing_sep_allowed: false,
+        }
+    }
+}
+
 impl<'a> Parser<'a> {
     pub fn new(
         sess: &'a ParseSess,
@@ -405,7 +429,7 @@ impl<'a> Parser<'a> {
         pprust::token_to_string(&self.token)
     }
 
-    crate fn token_descr(&self) -> Option<&'static str> {
+    fn token_descr(&self) -> Option<&'static str> {
         Some(match &self.token.kind {
             _ if self.token.is_special_ident() => "reserved identifier",
             _ if self.token.is_used_keyword() => "keyword",
@@ -415,7 +439,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    crate fn this_token_descr(&self) -> String {
+    pub(super) fn this_token_descr(&self) -> String {
         if let Some(prefix) = self.token_descr() {
             format!("{} `{}`", prefix, self.this_token_to_string())
         } else {
@@ -465,7 +489,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub fn parse_ident(&mut self) -> PResult<'a, ast::Ident> {
+    fn parse_ident(&mut self) -> PResult<'a, ast::Ident> {
         self.parse_ident_common(true)
     }
 
@@ -498,7 +522,7 @@ impl<'a> Parser<'a> {
     ///
     /// This method will automatically add `tok` to `expected_tokens` if `tok` is not
     /// encountered.
-    crate fn check(&mut self, tok: &TokenKind) -> bool {
+    fn check(&mut self, tok: &TokenKind) -> bool {
         let is_present = self.token == *tok;
         if !is_present { self.expected_tokens.push(TokenType::Token(tok.clone())); }
         is_present
@@ -520,7 +544,7 @@ impl<'a> Parser<'a> {
 
     /// If the next token is the given keyword, eats it and returns `true`.
     /// Otherwise, returns `false`. An expectation is also added for diagnostics purposes.
-    pub fn eat_keyword(&mut self, kw: Symbol) -> bool {
+    fn eat_keyword(&mut self, kw: Symbol) -> bool {
         if self.check_keyword(kw) {
             self.bump();
             true
@@ -558,7 +582,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn check_ident(&mut self) -> bool {
+    fn check_ident(&mut self) -> bool {
         self.check_or_expected(self.token.is_ident(), TokenType::Ident)
     }
 
@@ -723,7 +747,7 @@ impl<'a> Parser<'a> {
     /// Parses a sequence, including the closing delimiter. The function
     /// `f` must consume tokens until reaching the next separator or
     /// closing bracket.
-    pub fn parse_seq_to_end<T>(
+    fn parse_seq_to_end<T>(
         &mut self,
         ket: &TokenKind,
         sep: SeqSep,
@@ -739,7 +763,7 @@ impl<'a> Parser<'a> {
     /// Parses a sequence, not including the closing delimiter. The function
     /// `f` must consume tokens until reaching the next separator or
     /// closing bracket.
-    pub fn parse_seq_to_before_end<T>(
+    fn parse_seq_to_before_end<T>(
         &mut self,
         ket: &TokenKind,
         sep: SeqSep,
@@ -757,7 +781,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    crate fn parse_seq_to_before_tokens<T>(
+    fn parse_seq_to_before_tokens<T>(
         &mut self,
         kets: &[&TokenKind],
         sep: SeqSep,
@@ -1003,7 +1027,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn process_potential_macro_variable(&mut self) {
+    pub fn process_potential_macro_variable(&mut self) {
         self.token = match self.token.kind {
             token::Dollar if self.token.span.from_expansion() &&
                              self.look_ahead(1, |t| t.is_ident()) => {
@@ -1037,7 +1061,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a single token tree from the input.
-    crate fn parse_token_tree(&mut self) -> TokenTree {
+    pub fn parse_token_tree(&mut self) -> TokenTree {
         match self.token.kind {
             token::OpenDelim(..) => {
                 let frame = mem::replace(&mut self.token_cursor.frame,
@@ -1323,7 +1347,7 @@ impl<'a> Parser<'a> {
                                    *t == token::BinOp(token::Star))
     }
 
-    pub fn parse_optional_str(&mut self) -> Option<(Symbol, ast::StrStyle, Option<ast::Name>)> {
+    fn parse_optional_str(&mut self) -> Option<(Symbol, ast::StrStyle, Option<ast::Name>)> {
         let ret = match self.token.kind {
             token::Literal(token::Lit { kind: token::Str, symbol, suffix }) =>
                 (symbol, ast::StrStyle::Cooked, suffix),
diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/parser/attr.rs
index 0963efcfc8a..6f7d1ead4c1 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/parser/attr.rs
@@ -1,8 +1,7 @@
+use super::{SeqSep, PResult, Parser, TokenType, PathStyle};
 use crate::attr;
 use crate::ast;
-use crate::parse::{SeqSep, PResult};
 use crate::parse::token::{self, Nonterminal, DelimToken};
-use crate::parse::parser::{Parser, TokenType, PathStyle};
 use crate::tokenstream::{TokenStream, TokenTree};
 use crate::source_map::Span;
 
@@ -20,7 +19,7 @@ const DEFAULT_UNEXPECTED_INNER_ATTR_ERR_MSG: &str = "an inner attribute is not \
 
 impl<'a> Parser<'a> {
     /// Parses attributes that appear before an item.
-    crate fn parse_outer_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
+    pub(super) fn parse_outer_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
         let mut attrs: Vec<ast::Attribute> = Vec::new();
         let mut just_parsed_doc_comment = false;
         loop {
@@ -84,9 +83,10 @@ impl<'a> Parser<'a> {
 
     /// The same as `parse_attribute`, except it takes in an `InnerAttributeParsePolicy`
     /// that prescribes how to handle inner attributes.
-    fn parse_attribute_with_inner_parse_policy(&mut self,
-                                               inner_parse_policy: InnerAttributeParsePolicy<'_>)
-                                               -> PResult<'a, ast::Attribute> {
+    fn parse_attribute_with_inner_parse_policy(
+        &mut self,
+        inner_parse_policy: InnerAttributeParsePolicy<'_>
+    ) -> PResult<'a, ast::Attribute> {
         debug!("parse_attribute_with_inner_parse_policy: inner_parse_policy={:?} self.token={:?}",
                inner_parse_policy,
                self.token);
@@ -260,6 +260,27 @@ impl<'a> Parser<'a> {
         Ok(lit)
     }
 
+    /// Parses `cfg_attr(pred, attr_item_list)` where `attr_item_list` is comma-delimited.
+    crate fn parse_cfg_attr(&mut self) -> PResult<'a, (ast::MetaItem, Vec<(ast::AttrItem, Span)>)> {
+        self.expect(&token::OpenDelim(token::Paren))?;
+
+        let cfg_predicate = self.parse_meta_item()?;
+        self.expect(&token::Comma)?;
+
+        // Presumably, the majority of the time there will only be one attr.
+        let mut expanded_attrs = Vec::with_capacity(1);
+
+        while !self.check(&token::CloseDelim(token::Paren)) {
+            let lo = self.token.span.lo();
+            let item = self.parse_attr_item()?;
+            expanded_attrs.push((item, self.prev_span.with_lo(lo)));
+            self.expect_one_of(&[token::Comma], &[token::CloseDelim(token::Paren)])?;
+        }
+
+        self.expect(&token::CloseDelim(token::Paren))?;
+        Ok((cfg_predicate, expanded_attrs))
+    }
+
     /// Matches the following grammar (per RFC 1559).
     ///
     ///     meta_item : PATH ( '=' UNSUFFIXED_LIT | '(' meta_item_inner? ')' )? ;
diff --git a/src/libsyntax/parse/diagnostics.rs b/src/libsyntax/parse/parser/diagnostics.rs
index 943838d9dda..06982c789db 100644
--- a/src/libsyntax/parse/diagnostics.rs
+++ b/src/libsyntax/parse/parser/diagnostics.rs
@@ -1,9 +1,11 @@
+use super::{
+    BlockMode, PathStyle, SemiColonMode, TokenType, TokenExpectType,
+    SeqSep, PResult, Parser
+};
 use crate::ast::{
     self, Param, BinOpKind, BindingMode, BlockCheckMode, Expr, ExprKind, Ident, Item, ItemKind,
     Mutability, Pat, PatKind, PathSegment, QSelf, Ty, TyKind,
 };
-use crate::parse::{SeqSep, PResult, Parser};
-use crate::parse::parser::{BlockMode, PathStyle, SemiColonMode, TokenType, TokenExpectType};
 use crate::parse::token::{self, TokenKind};
 use crate::print::pprust;
 use crate::ptr::P;
@@ -17,8 +19,9 @@ use log::{debug, trace};
 use std::mem;
 
 const TURBOFISH: &'static str = "use `::<...>` instead of `<...>` to specify type arguments";
+
 /// Creates a placeholder argument.
-crate fn dummy_arg(ident: Ident) -> Param {
+pub(super) fn dummy_arg(ident: Ident) -> Param {
     let pat = P(Pat {
         id: ast::DUMMY_NODE_ID,
         kind: PatKind::Ident(BindingMode::ByValue(Mutability::Immutable), ident, None),
@@ -121,7 +124,7 @@ impl Error {
     }
 }
 
-pub trait RecoverQPath: Sized + 'static {
+pub(super) trait RecoverQPath: Sized + 'static {
     const PATH_STYLE: PathStyle = PathStyle::Expr;
     fn to_ty(&self) -> Option<P<Ty>>;
     fn recovered(qself: Option<QSelf>, path: ast::Path) -> Self;
@@ -173,39 +176,43 @@ impl<'a> Parser<'a> {
         self.span_fatal(self.token.span, m)
     }
 
-    pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
+    crate fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
         self.sess.span_diagnostic.struct_span_fatal(sp, m)
     }
 
-    pub fn span_fatal_err<S: Into<MultiSpan>>(&self, sp: S, err: Error) -> DiagnosticBuilder<'a> {
+    pub(super) fn span_fatal_err<S: Into<MultiSpan>>(
+        &self,
+        sp: S,
+        err: Error,
+    ) -> DiagnosticBuilder<'a> {
         err.span_err(sp, self.diagnostic())
     }
 
-    pub fn bug(&self, m: &str) -> ! {
+    pub(super) fn bug(&self, m: &str) -> ! {
         self.sess.span_diagnostic.span_bug(self.token.span, m)
     }
 
-    pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) {
+    pub(super) fn span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) {
         self.sess.span_diagnostic.span_err(sp, m)
     }
 
-    crate fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
+    pub fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
         self.sess.span_diagnostic.struct_span_err(sp, m)
     }
 
-    crate fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> ! {
+    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> ! {
         self.sess.span_diagnostic.span_bug(sp, m)
     }
 
-    crate fn diagnostic(&self) -> &'a errors::Handler {
+    pub(super) fn diagnostic(&self) -> &'a errors::Handler {
         &self.sess.span_diagnostic
     }
 
-    crate fn span_to_snippet(&self, span: Span) -> Result<String, SpanSnippetError> {
+    pub(super) fn span_to_snippet(&self, span: Span) -> Result<String, SpanSnippetError> {
         self.sess.source_map().span_to_snippet(span)
     }
 
-    crate fn expected_ident_found(&self) -> DiagnosticBuilder<'a> {
+    pub(super) fn expected_ident_found(&self) -> DiagnosticBuilder<'a> {
         let mut err = self.struct_span_err(
             self.token.span,
             &format!("expected identifier, found {}", self.this_token_descr()),
@@ -236,7 +243,7 @@ impl<'a> Parser<'a> {
         err
     }
 
-    pub fn expected_one_of_not_found(
+    pub(super) fn expected_one_of_not_found(
         &mut self,
         edible: &[TokenKind],
         inedible: &[TokenKind],
@@ -423,7 +430,7 @@ impl<'a> Parser<'a> {
 
     /// Eats and discards tokens until one of `kets` is encountered. Respects token trees,
     /// passes through any errors encountered. Used for error recovery.
-    crate fn eat_to_tokens(&mut self, kets: &[&TokenKind]) {
+    pub(super) fn eat_to_tokens(&mut self, kets: &[&TokenKind]) {
         if let Err(ref mut err) = self.parse_seq_to_before_tokens(
             kets,
             SeqSep::none(),
@@ -441,7 +448,7 @@ impl<'a> Parser<'a> {
     /// let _ = vec![1, 2, 3].into_iter().collect::<Vec<usize>>>>();
     ///                                                        ^^ help: remove extra angle brackets
     /// ```
-    crate fn check_trailing_angle_brackets(&mut self, segment: &PathSegment, end: TokenKind) {
+    pub(super) fn check_trailing_angle_brackets(&mut self, segment: &PathSegment, end: TokenKind) {
         // This function is intended to be invoked after parsing a path segment where there are two
         // cases:
         //
@@ -560,7 +567,7 @@ impl<'a> Parser<'a> {
     ///     inner_op   r2
     ///        /  \
     ///     l1    r1
-    crate fn check_no_chained_comparison(
+    pub(super) fn check_no_chained_comparison(
         &mut self,
         lhs: &Expr,
         outer_op: &AssocOp,
@@ -695,7 +702,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn maybe_report_ambiguous_plus(
+    pub(super) fn maybe_report_ambiguous_plus(
         &mut self,
         allow_plus: bool,
         impl_dyn_multi: bool,
@@ -768,7 +775,7 @@ impl<'a> Parser<'a> {
     /// Tries to recover from associated item paths like `[T]::AssocItem` / `(T, U)::AssocItem`.
     /// Attempts to convert the base expression/pattern/type into a type, parses the `::AssocItem`
     /// tail, and combines them into a `<Ty>::AssocItem` expression/pattern/type.
-    crate fn maybe_recover_from_bad_qpath<T: RecoverQPath>(
+    pub(super) fn maybe_recover_from_bad_qpath<T: RecoverQPath>(
         &mut self,
         base: P<T>,
         allow_recovery: bool,
@@ -784,7 +791,7 @@ impl<'a> Parser<'a> {
 
     /// Given an already parsed `Ty`, parses the `::AssocItem` tail and
     /// combines them into a `<Ty>::AssocItem` expression/pattern/type.
-    crate fn maybe_recover_from_bad_qpath_stage_2<T: RecoverQPath>(
+    pub(super) fn maybe_recover_from_bad_qpath_stage_2<T: RecoverQPath>(
         &mut self,
         ty_span: Span,
         ty: P<Ty>,
@@ -823,7 +830,7 @@ impl<'a> Parser<'a> {
         )))
     }
 
-    crate fn maybe_consume_incorrect_semicolon(&mut self, items: &[P<Item>]) -> bool {
+    pub(super) fn maybe_consume_incorrect_semicolon(&mut self, items: &[P<Item>]) -> bool {
         if self.eat(&token::Semi) {
             let mut err = self.struct_span_err(self.prev_span, "expected item, found `;`");
             err.span_suggestion_short(
@@ -859,7 +866,7 @@ impl<'a> Parser<'a> {
 
     /// Creates a `DiagnosticBuilder` for an unexpected token `t` and tries to recover if it is a
     /// closing delimiter.
-    pub fn unexpected_try_recover(
+    pub(super) fn unexpected_try_recover(
         &mut self,
         t: &TokenKind,
     ) -> PResult<'a, bool /* recovered */> {
@@ -909,7 +916,7 @@ impl<'a> Parser<'a> {
         Err(err)
     }
 
-    crate fn parse_semi_or_incorrect_foreign_fn_body(
+    pub(super) fn parse_semi_or_incorrect_foreign_fn_body(
         &mut self,
         ident: &Ident,
         extern_sp: Span,
@@ -947,7 +954,7 @@ impl<'a> Parser<'a> {
 
     /// Consumes alternative await syntaxes like `await!(<expr>)`, `await <expr>`,
     /// `await? <expr>`, `await(<expr>)`, and `await { <expr> }`.
-    crate fn parse_incorrect_await_syntax(
+    pub(super) fn parse_incorrect_await_syntax(
         &mut self,
         lo: Span,
         await_sp: Span,
@@ -999,7 +1006,7 @@ impl<'a> Parser<'a> {
     }
 
     /// If encountering `future.await()`, consumes and emits an error.
-    crate fn recover_from_await_method_call(&mut self) {
+    pub(super) fn recover_from_await_method_call(&mut self) {
         if self.token == token::OpenDelim(token::Paren) &&
             self.look_ahead(1, |t| t == &token::CloseDelim(token::Paren))
         {
@@ -1022,7 +1029,7 @@ impl<'a> Parser<'a> {
     /// and suggest writing `for $pat in $expr` instead.
     ///
     /// This should be called before parsing the `$block`.
-    crate fn recover_parens_around_for_head(
+    pub(super) fn recover_parens_around_for_head(
         &mut self,
         pat: P<Pat>,
         expr: &Expr,
@@ -1060,7 +1067,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn could_ascription_be_path(&self, node: &ast::ExprKind) -> bool {
+    pub(super) fn could_ascription_be_path(&self, node: &ast::ExprKind) -> bool {
         self.token.is_ident() &&
             if let ast::ExprKind::Path(..) = node { true } else { false } &&
             !self.token.is_reserved_ident() &&           // v `foo:bar(baz)`
@@ -1074,7 +1081,7 @@ impl<'a> Parser<'a> {
              self.look_ahead(2, |t| t == &token::Lt))  // `foo:bar::<baz>`
     }
 
-    crate fn recover_seq_parse_error(
+    pub(super) fn recover_seq_parse_error(
         &mut self,
         delim: token::DelimToken,
         lo: Span,
@@ -1091,7 +1098,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn recover_closing_delimiter(
+    pub(super) fn recover_closing_delimiter(
         &mut self,
         tokens: &[TokenKind],
         mut err: DiagnosticBuilder<'a>,
@@ -1142,7 +1149,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Recovers from `pub` keyword in places where it seems _reasonable_ but isn't valid.
-    crate fn eat_bad_pub(&mut self) {
+    pub(super) fn eat_bad_pub(&mut self) {
         if self.token.is_keyword(kw::Pub) {
             match self.parse_visibility(false) {
                 Ok(vis) => {
@@ -1160,7 +1167,7 @@ impl<'a> Parser<'a> {
     /// statement. This is something of a best-effort heuristic.
     ///
     /// We terminate when we find an unmatched `}` (without consuming it).
-    crate fn recover_stmt(&mut self) {
+    pub(super) fn recover_stmt(&mut self) {
         self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore)
     }
 
@@ -1171,7 +1178,11 @@ impl<'a> Parser<'a> {
     ///
     /// If `break_on_block` is `Break`, then we will stop consuming tokens
     /// after finding (and consuming) a brace-delimited block.
-    crate fn recover_stmt_(&mut self, break_on_semi: SemiColonMode, break_on_block: BlockMode) {
+    pub(super) fn recover_stmt_(
+        &mut self,
+        break_on_semi: SemiColonMode,
+        break_on_block: BlockMode,
+    ) {
         let mut brace_depth = 0;
         let mut bracket_depth = 0;
         let mut in_block = false;
@@ -1239,7 +1250,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn check_for_for_in_in_typo(&mut self, in_span: Span) {
+    pub(super) fn check_for_for_in_in_typo(&mut self, in_span: Span) {
         if self.eat_keyword(kw::In) {
             // a common typo: `for _ in in bar {}`
             self.struct_span_err(self.prev_span, "expected iterable, found keyword `in`")
@@ -1253,14 +1264,14 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn expected_semi_or_open_brace<T>(&mut self) -> PResult<'a, T> {
+    pub(super) fn expected_semi_or_open_brace<T>(&mut self) -> PResult<'a, T> {
         let token_str = self.this_token_descr();
         let mut err = self.fatal(&format!("expected `;` or `{{`, found {}", token_str));
         err.span_label(self.token.span, "expected `;` or `{`");
         Err(err)
     }
 
-    crate fn eat_incorrect_doc_comment_for_param_type(&mut self) {
+    pub(super) fn eat_incorrect_doc_comment_for_param_type(&mut self) {
         if let token::DocComment(_) = self.token.kind {
             self.struct_span_err(
                 self.token.span,
@@ -1288,7 +1299,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn parameter_without_type(
+    pub(super) fn parameter_without_type(
         &mut self,
         err: &mut DiagnosticBuilder<'_>,
         pat: P<ast::Pat>,
@@ -1351,7 +1362,7 @@ impl<'a> Parser<'a> {
         None
     }
 
-    crate fn recover_arg_parse(&mut self) -> PResult<'a, (P<ast::Pat>, P<ast::Ty>)> {
+    pub(super) fn recover_arg_parse(&mut self) -> PResult<'a, (P<ast::Pat>, P<ast::Ty>)> {
         let pat = self.parse_pat(Some("argument name"))?;
         self.expect(&token::Colon)?;
         let ty = self.parse_ty()?;
@@ -1379,7 +1390,7 @@ impl<'a> Parser<'a> {
         Ok((pat, ty))
     }
 
-    crate fn recover_bad_self_param(
+    pub(super) fn recover_bad_self_param(
         &mut self,
         mut param: ast::Param,
         is_trait_item: bool,
@@ -1397,7 +1408,7 @@ impl<'a> Parser<'a> {
         Ok(param)
     }
 
-    crate fn consume_block(&mut self, delim: token::DelimToken) {
+    pub(super) fn consume_block(&mut self, delim: token::DelimToken) {
         let mut brace_depth = 0;
         loop {
             if self.eat(&token::OpenDelim(delim)) {
@@ -1417,7 +1428,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn expected_expression_found(&self) -> DiagnosticBuilder<'a> {
+    pub(super) fn expected_expression_found(&self) -> DiagnosticBuilder<'a> {
         let (span, msg) = match (&self.token.kind, self.subparser_name) {
             (&token::Eof, Some(origin)) => {
                 let sp = self.sess.source_map().next_point(self.token.span);
@@ -1462,7 +1473,7 @@ impl<'a> Parser<'a> {
     /// the parameters are *names* (so we don't emit errors about not being able to find `b` in
     /// the local scope), but if we find the same name multiple times, like in `fn foo(i8, i8)`,
     /// we deduplicate them to not complain about duplicated parameter names.
-    crate fn deduplicate_recovered_params_names(&self, fn_inputs: &mut Vec<Param>) {
+    pub(super) fn deduplicate_recovered_params_names(&self, fn_inputs: &mut Vec<Param>) {
         let mut seen_inputs = FxHashSet::default();
         for input in fn_inputs.iter_mut() {
             let opt_ident = if let (PatKind::Ident(_, ident, _), TyKind::Err) = (
diff --git a/src/libsyntax/parse/parser/expr.rs b/src/libsyntax/parse/parser/expr.rs
index dd0fd834fb0..273f5a5ffa3 100644
--- a/src/libsyntax/parse/parser/expr.rs
+++ b/src/libsyntax/parse/parser/expr.rs
@@ -1,6 +1,7 @@
 use super::{Parser, PResult, Restrictions, PrevTokenKind, TokenType, PathStyle, BlockMode};
 use super::{SemiColonMode, SeqSep, TokenExpectType};
 use super::pat::{GateOr, PARAM_EXPECTED};
+use super::diagnostics::Error;
 
 use crate::parse::literal::LitError;
 
@@ -12,7 +13,6 @@ use crate::ast::{
 use crate::maybe_recover_from_interpolated_ty_qpath;
 use crate::parse::classify;
 use crate::parse::token::{self, Token, TokenKind};
-use crate::parse::diagnostics::Error;
 use crate::print::pprust;
 use crate::ptr::P;
 use crate::source_map::{self, Span};
@@ -1074,7 +1074,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Matches `lit = true | false | token_lit`.
-    crate fn parse_lit(&mut self) -> PResult<'a, Lit> {
+    pub(super) fn parse_lit(&mut self) -> PResult<'a, Lit> {
         let mut recovered = None;
         if self.token == token::Dot {
             // Attempt to recover `.4` as `0.4`.
@@ -1233,7 +1233,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Matches `'-' lit | lit` (cf. `ast_validation::AstValidator::check_expr_within_pat`).
-    crate fn parse_literal_maybe_minus(&mut self) -> PResult<'a, P<Expr>> {
+    pub fn parse_literal_maybe_minus(&mut self) -> PResult<'a, P<Expr>> {
         maybe_whole_expr!(self);
 
         let minus_lo = self.token.span;
@@ -1253,7 +1253,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a block or unsafe block.
-    crate fn parse_block_expr(
+    pub(super) fn parse_block_expr(
         &mut self,
         opt_label: Option<Label>,
         lo: Span,
@@ -1558,7 +1558,7 @@ impl<'a> Parser<'a> {
         return Ok(self.mk_expr(lo.to(hi), ExprKind::Match(discriminant, arms), attrs));
     }
 
-    crate fn parse_arm(&mut self) -> PResult<'a, Arm> {
+    pub(super) fn parse_arm(&mut self) -> PResult<'a, Arm> {
         let attrs = self.parse_outer_attributes()?;
         let lo = self.token.span;
         let pat = self.parse_top_pat(GateOr::No)?;
@@ -1666,7 +1666,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses an `async move? {...}` expression.
-    pub fn parse_async_block(&mut self, mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
+    fn parse_async_block(&mut self, mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         let span_lo = self.token.span;
         self.expect_keyword(kw::Async)?;
         let capture_clause = self.parse_capture_clause();
@@ -1946,4 +1946,8 @@ impl<'a> Parser<'a> {
     crate fn mk_expr(&self, span: Span, kind: ExprKind, attrs: ThinVec<Attribute>) -> P<Expr> {
         P(Expr { kind, span, attrs, id: DUMMY_NODE_ID })
     }
+
+    pub(super) fn mk_expr_err(&self, span: Span) -> P<Expr> {
+        self.mk_expr(span, ExprKind::Err, ThinVec::new())
+    }
 }
diff --git a/src/libsyntax/parse/parser/generics.rs b/src/libsyntax/parse/parser/generics.rs
index 2ecd9cca3c6..bfcb0042a75 100644
--- a/src/libsyntax/parse/parser/generics.rs
+++ b/src/libsyntax/parse/parser/generics.rs
@@ -74,7 +74,7 @@ impl<'a> Parser<'a> {
 
     /// Parses a (possibly empty) list of lifetime and type parameters, possibly including
     /// a trailing comma and erroneous trailing attributes.
-    crate fn parse_generic_params(&mut self) -> PResult<'a, Vec<ast::GenericParam>> {
+    pub(super) fn parse_generic_params(&mut self) -> PResult<'a, Vec<ast::GenericParam>> {
         let mut params = Vec::new();
         loop {
             let attrs = self.parse_outer_attributes()?;
diff --git a/src/libsyntax/parse/parser/item.rs b/src/libsyntax/parse/parser/item.rs
index 08c624b5539..0acfd1450d8 100644
--- a/src/libsyntax/parse/parser/item.rs
+++ b/src/libsyntax/parse/parser/item.rs
@@ -1,4 +1,6 @@
 use super::{Parser, PResult, PathStyle, SemiColonMode, BlockMode};
+use super::diagnostics::{Error, dummy_arg};
+
 use crate::maybe_whole;
 use crate::ptr::P;
 use crate::ast::{self, DUMMY_NODE_ID, Ident, Attribute, AttrStyle, AnonConst, Item, ItemKind};
@@ -7,10 +9,8 @@ use crate::ast::{PathSegment, IsAuto, Constness, IsAsync, Unsafety, Defaultness}
 use crate::ast::{Visibility, VisibilityKind, Mutability, FnHeader, ForeignItem, ForeignItemKind};
 use crate::ast::{Ty, TyKind, Generics, GenericBounds, TraitRef, EnumDef, VariantData, StructField};
 use crate::ast::{Mac, MacDelimiter, Block, BindingMode, FnDecl, MethodSig, SelfKind, Param};
-use crate::ext::base::DummyResult;
 use crate::parse::token;
 use crate::parse::parser::maybe_append;
-use crate::parse::diagnostics::{Error, dummy_arg};
 use crate::tokenstream::{TokenTree, TokenStream};
 use crate::symbol::{kw, sym};
 use crate::source_map::{self, respan, Span};
@@ -23,7 +23,7 @@ use errors::{Applicability, DiagnosticBuilder, DiagnosticId, StashKey};
 
 /// Whether the type alias or associated type is a concrete type or an opaque type.
 #[derive(Debug)]
-pub enum AliasKind {
+pub(super) enum AliasKind {
     /// Just a new name for the same type.
     Weak(P<Ty>),
     /// Only trait impls of the type will be usable, not the actual type itself.
@@ -605,7 +605,7 @@ impl<'a> Parser<'a> {
         let ty_second = if self.token == token::DotDot {
             // We need to report this error after `cfg` expansion for compatibility reasons
             self.bump(); // `..`, do not add it to expected tokens
-            Some(DummyResult::raw_ty(self.prev_span, true))
+            Some(self.mk_ty(self.prev_span, TyKind::Err))
         } else if has_for || self.token.can_begin_type() {
             Some(self.parse_ty()?)
         } else {
@@ -1116,7 +1116,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a foreign item.
-    crate fn parse_foreign_item(&mut self, extern_sp: Span) -> PResult<'a, ForeignItem> {
+    pub fn parse_foreign_item(&mut self, extern_sp: Span) -> PResult<'a, ForeignItem> {
         maybe_whole!(self, NtForeignItem, |ni| ni);
 
         let attrs = self.parse_outer_attributes()?;
diff --git a/src/libsyntax/parse/parser/module.rs b/src/libsyntax/parse/parser/module.rs
index 2d2fb487d7d..a0e4d2bbb7a 100644
--- a/src/libsyntax/parse/parser/module.rs
+++ b/src/libsyntax/parse/parser/module.rs
@@ -1,24 +1,24 @@
 use super::{Parser, PResult};
 use super::item::ItemInfo;
+use super::diagnostics::Error;
 
 use crate::attr;
 use crate::ast::{self, Ident, Attribute, ItemKind, Mod, Crate};
 use crate::parse::{new_sub_parser_from_file, DirectoryOwnership};
 use crate::parse::token::{self, TokenKind};
-use crate::parse::diagnostics::{Error};
 use crate::source_map::{SourceMap, Span, DUMMY_SP, FileName};
 use crate::symbol::sym;
 
 use std::path::{self, Path, PathBuf};
 
 /// Information about the path to a module.
-pub struct ModulePath {
+pub(super) struct ModulePath {
     name: String,
     path_exists: bool,
     pub result: Result<ModulePathSuccess, Error>,
 }
 
-pub struct ModulePathSuccess {
+pub(super) struct ModulePathSuccess {
     pub path: PathBuf,
     pub directory_ownership: DirectoryOwnership,
     warn: bool,
@@ -39,6 +39,8 @@ impl<'a> Parser<'a> {
     /// Parses a `mod <foo> { ... }` or `mod <foo>;` item.
     pub(super) fn parse_item_mod(&mut self, outer_attrs: &[Attribute]) -> PResult<'a, ItemInfo> {
         let (in_cfg, outer_attrs) = {
+            // FIXME(Centril): This results in a cycle between config and parsing.
+            // Consider using dynamic dispatch via `self.sess` to disentangle the knot.
             let mut strip_unconfigured = crate::config::StripUnconfigured {
                 sess: self.sess,
                 features: None, // Don't perform gated feature checking.
@@ -198,7 +200,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub fn submod_path_from_attr(attrs: &[Attribute], dir_path: &Path) -> Option<PathBuf> {
+    pub(super) fn submod_path_from_attr(attrs: &[Attribute], dir_path: &Path) -> Option<PathBuf> {
         if let Some(s) = attr::first_attr_value_str_by_name(attrs, sym::path) {
             let s = s.as_str();
 
@@ -215,7 +217,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Returns a path to a module.
-    pub fn default_submod_path(
+    pub(super) fn default_submod_path(
         id: ast::Ident,
         relative: Option<ast::Ident>,
         dir_path: &Path,
diff --git a/src/libsyntax/parse/parser/pat.rs b/src/libsyntax/parse/parser/pat.rs
index e288346a329..af795e51792 100644
--- a/src/libsyntax/parse/parser/pat.rs
+++ b/src/libsyntax/parse/parser/pat.rs
@@ -22,7 +22,7 @@ const WHILE_PARSING_OR_MSG: &str = "while parsing this or-pattern starting here"
 
 /// Whether or not an or-pattern should be gated when occurring in the current context.
 #[derive(PartialEq)]
-pub enum GateOr { Yes, No }
+pub(super) enum GateOr { Yes, No }
 
 /// Whether or not to recover a `,` when parsing or-patterns.
 #[derive(PartialEq, Copy, Clone)]
diff --git a/src/libsyntax/parse/parser/path.rs b/src/libsyntax/parse/parser/path.rs
index ca823991a2e..639d61a2b5c 100644
--- a/src/libsyntax/parse/parser/path.rs
+++ b/src/libsyntax/parse/parser/path.rs
@@ -111,7 +111,7 @@ impl<'a> Parser<'a> {
     /// Like `parse_path`, but also supports parsing `Word` meta items into paths for
     /// backwards-compatibility. This is used when parsing derive macro paths in `#[derive]`
     /// attributes.
-    pub fn parse_path_allowing_meta(&mut self, style: PathStyle) -> PResult<'a, Path> {
+    fn parse_path_allowing_meta(&mut self, style: PathStyle) -> PResult<'a, Path> {
         let meta_ident = match self.token.kind {
             token::Interpolated(ref nt) => match **nt {
                 token::NtMeta(ref item) => match item.tokens.is_empty() {
@@ -129,7 +129,22 @@ impl<'a> Parser<'a> {
         self.parse_path(style)
     }
 
-    crate fn parse_path_segments(
+    /// Parse a list of paths inside `#[derive(path_0, ..., path_n)]`.
+    crate fn parse_derive_paths(&mut self) -> PResult<'a, Vec<Path>> {
+        self.expect(&token::OpenDelim(token::Paren))?;
+        let mut list = Vec::new();
+        while !self.eat(&token::CloseDelim(token::Paren)) {
+            let path = self.parse_path_allowing_meta(PathStyle::Mod)?;
+            list.push(path);
+            if !self.eat(&token::Comma) {
+                self.expect(&token::CloseDelim(token::Paren))?;
+                break
+            }
+        }
+        Ok(list)
+    }
+
+    pub(super) fn parse_path_segments(
         &mut self,
         segments: &mut Vec<PathSegment>,
         style: PathStyle,
diff --git a/src/libsyntax/parse/parser/stmt.rs b/src/libsyntax/parse/parser/stmt.rs
index 855b03ddd6f..d54d9c4b8e9 100644
--- a/src/libsyntax/parse/parser/stmt.rs
+++ b/src/libsyntax/parse/parser/stmt.rs
@@ -2,14 +2,13 @@ use super::{Parser, PResult, Restrictions, PrevTokenKind, SemiColonMode, BlockMo
 use super::expr::LhsExpr;
 use super::path::PathStyle;
 use super::pat::GateOr;
+use super::diagnostics::Error;
 
 use crate::ptr::P;
 use crate::{maybe_whole, ThinVec};
 use crate::ast::{self, DUMMY_NODE_ID, Stmt, StmtKind, Local, Block, BlockCheckMode, Expr, ExprKind};
 use crate::ast::{Attribute, AttrStyle, VisibilityKind, MacStmtStyle, Mac, MacDelimiter};
-use crate::ext::base::DummyResult;
 use crate::parse::{classify, DirectoryOwnership};
-use crate::parse::diagnostics::Error;
 use crate::parse::token;
 use crate::source_map::{respan, Span};
 use crate::symbol::{kw, sym};
@@ -373,7 +372,9 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a block. Inner attributes are allowed.
-    crate fn parse_inner_attrs_and_block(&mut self) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
+    pub(super) fn parse_inner_attrs_and_block(
+        &mut self
+    ) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
         maybe_whole!(self, NtBlock, |x| (Vec::new(), x));
 
         let lo = self.token.span;
@@ -400,7 +401,7 @@ impl<'a> Parser<'a> {
                     self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore);
                     Some(Stmt {
                         id: DUMMY_NODE_ID,
-                        kind: StmtKind::Expr(DummyResult::raw_expr(self.token.span, true)),
+                        kind: StmtKind::Expr(self.mk_expr_err(self.token.span)),
                         span: self.token.span,
                     })
                 }
@@ -422,7 +423,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a statement, including the trailing semicolon.
-    crate fn parse_full_stmt(&mut self, macro_legacy_warnings: bool) -> PResult<'a, Option<Stmt>> {
+    pub fn parse_full_stmt(&mut self, macro_legacy_warnings: bool) -> PResult<'a, Option<Stmt>> {
         // Skip looking for a trailing semicolon when we have an interpolated statement.
         maybe_whole!(self, NtStmt, |x| Some(x));
 
@@ -443,7 +444,7 @@ impl<'a> Parser<'a> {
                         self.recover_stmt();
                         // Don't complain about type errors in body tail after parse error (#57383).
                         let sp = expr.span.to(self.prev_span);
-                        stmt.kind = StmtKind::Expr(DummyResult::raw_expr(sp, true));
+                        stmt.kind = StmtKind::Expr(self.mk_expr_err(sp));
                     }
                 }
             }
diff --git a/src/libsyntax/parse/parser/ty.rs b/src/libsyntax/parse/parser/ty.rs
index e696ab0804d..86c94b680b2 100644
--- a/src/libsyntax/parse/parser/ty.rs
+++ b/src/libsyntax/parse/parser/ty.rs
@@ -210,7 +210,7 @@ impl<'a> Parser<'a> {
         };
 
         let span = lo.to(self.prev_span);
-        let ty = P(Ty { kind, span, id: ast::DUMMY_NODE_ID });
+        let ty = self.mk_ty(span, kind);
 
         // Try to recover from use of `+` with incorrect priority.
         self.maybe_report_ambiguous_plus(allow_plus, impl_dyn_multi, &ty);
@@ -296,7 +296,7 @@ impl<'a> Parser<'a> {
         })))
     }
 
-    crate fn parse_generic_bounds(&mut self,
+    pub(super) fn parse_generic_bounds(&mut self,
                                   colon_span: Option<Span>) -> PResult<'a, GenericBounds> {
         self.parse_generic_bounds_common(true, colon_span)
     }
@@ -433,13 +433,13 @@ impl<'a> Parser<'a> {
         }
     }
 
-    crate fn check_lifetime(&mut self) -> bool {
+    pub fn check_lifetime(&mut self) -> bool {
         self.expected_tokens.push(TokenType::Lifetime);
         self.token.is_lifetime()
     }
 
     /// Parses a single lifetime `'a` or panics.
-    crate fn expect_lifetime(&mut self) -> Lifetime {
+    pub fn expect_lifetime(&mut self) -> Lifetime {
         if let Some(ident) = self.token.lifetime() {
             let span = self.token.span;
             self.bump();
@@ -448,4 +448,8 @@ impl<'a> Parser<'a> {
             self.span_bug(self.token.span, "not a lifetime")
         }
     }
+
+    pub(super) fn mk_ty(&self, span: Span, kind: TyKind) -> P<Ty> {
+        P(Ty { kind, span, id: ast::DUMMY_NODE_ID })
+    }
 }
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index eb74ab2b919..e527989fb0b 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -285,7 +285,7 @@ impl TokenKind {
 }
 
 impl Token {
-    crate fn new(kind: TokenKind, span: Span) -> Self {
+    pub fn new(kind: TokenKind, span: Span) -> Self {
         Token { kind, span }
     }
 
@@ -295,12 +295,12 @@ impl Token {
     }
 
     /// Recovers a `Token` from an `ast::Ident`. This creates a raw identifier if necessary.
-    crate fn from_ast_ident(ident: ast::Ident) -> Self {
+    pub fn from_ast_ident(ident: ast::Ident) -> Self {
         Token::new(Ident(ident.name, ident.is_raw_guess()), ident.span)
     }
 
     /// Return this token by value and leave a dummy token in its place.
-    crate fn take(&mut self) -> Self {
+    pub fn take(&mut self) -> Self {
         mem::replace(self, Token::dummy())
     }
 
@@ -321,7 +321,7 @@ impl Token {
     }
 
     /// Returns `true` if the token can appear at the start of an expression.
-    crate fn can_begin_expr(&self) -> bool {
+    pub fn can_begin_expr(&self) -> bool {
         match self.kind {
             Ident(name, is_raw)              =>
                 ident_can_begin_expr(name, self.span, is_raw), // value name or keyword
@@ -353,7 +353,7 @@ impl Token {
     }
 
     /// Returns `true` if the token can appear at the start of a type.
-    crate fn can_begin_type(&self) -> bool {
+    pub fn can_begin_type(&self) -> bool {
         match self.kind {
             Ident(name, is_raw)        =>
                 ident_can_begin_type(name, self.span, is_raw), // type name or keyword
@@ -396,7 +396,7 @@ impl Token {
     }
 
     /// Returns `true` if the token is any literal
-    crate fn is_lit(&self) -> bool {
+    pub fn is_lit(&self) -> bool {
         match self.kind {
             Literal(..) => true,
             _           => false,
@@ -412,7 +412,7 @@ impl Token {
 
     /// Returns `true` if the token is any literal, a minus (which can prefix a literal,
     /// for example a '-42', or one of the boolean idents).
-    crate fn can_begin_literal_or_bool(&self) -> bool {
+    pub fn can_begin_literal_or_bool(&self) -> bool {
         match self.kind {
             Literal(..) | BinOp(Minus) => true,
             Ident(name, false) if name.is_bool_lit() => true,