Rollup merge of #126052 - nnethercote:rustc_parse-more-cleanups, r=spastorino

More `rustc_parse` cleanups

Following on from #125815.

r? `@spastorino`

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -130,14 +130,14 @@ pub enum AttemptLocalParseRecovery {
 }
 
 impl AttemptLocalParseRecovery {
-    pub fn yes(&self) -> bool {
+    pub(super) fn yes(&self) -> bool {
         match self {
             AttemptLocalParseRecovery::Yes => true,
             AttemptLocalParseRecovery::No => false,
         }
     }
 
-    pub fn no(&self) -> bool {
+    pub(super) fn no(&self) -> bool {
         match self {
             AttemptLocalParseRecovery::Yes => false,
             AttemptLocalParseRecovery::No => true,
@@ -891,7 +891,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub fn maybe_suggest_struct_literal(
+    pub(super) fn maybe_suggest_struct_literal(
         &mut self,
         lo: Span,
         s: BlockCheckMode,
@@ -2459,7 +2459,7 @@ impl<'a> Parser<'a> {
     /// Handle encountering a symbol in a generic argument list that is not a `,` or `>`. In this
     /// case, we emit an error and try to suggest enclosing a const argument in braces if it looks
     /// like the user has forgotten them.
-    pub fn handle_ambiguous_unbraced_const_arg(
+    pub(super) fn handle_ambiguous_unbraced_const_arg(
         &mut self,
         args: &mut ThinVec<AngleBracketedArg>,
     ) -> PResult<'a, bool> {
@@ -2500,7 +2500,7 @@ impl<'a> Parser<'a> {
     /// - Single-segment paths (i.e. standalone generic const parameters).
     /// All other expressions that can be parsed will emit an error suggesting the expression be
     /// wrapped in braces.
-    pub fn handle_unambiguous_unbraced_const_arg(&mut self) -> PResult<'a, P<Expr>> {
+    pub(super) fn handle_unambiguous_unbraced_const_arg(&mut self) -> PResult<'a, P<Expr>> {
         let start = self.token.span;
         let expr = self.parse_expr_res(Restrictions::CONST_EXPR, None).map_err(|mut err| {
             err.span_label(
@@ -2559,7 +2559,7 @@ impl<'a> Parser<'a> {
         Some(GenericArg::Const(AnonConst { id: ast::DUMMY_NODE_ID, value }))
     }
 
-    pub fn recover_const_param_declaration(
+    pub(super) fn recover_const_param_declaration(
         &mut self,
         ty_generics: Option<&Generics>,
     ) -> PResult<'a, Option<GenericArg>> {
@@ -2589,7 +2589,11 @@ impl<'a> Parser<'a> {
     /// When encountering code like `foo::< bar + 3 >` or `foo::< bar - baz >` we suggest
     /// `foo::<{ bar + 3 }>` and `foo::<{ bar - baz }>`, respectively. We only provide a suggestion
     /// if we think that the resulting expression would be well formed.
-    pub fn recover_const_arg(&mut self, start: Span, mut err: Diag<'a>) -> PResult<'a, GenericArg> {
+    pub(super) fn recover_const_arg(
+        &mut self,
+        start: Span,
+        mut err: Diag<'a>,
+    ) -> PResult<'a, GenericArg> {
         let is_op_or_dot = AssocOp::from_token(&self.token)
             .and_then(|op| {
                 if let AssocOp::Greater
@@ -2690,7 +2694,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Creates a dummy const argument, and reports that the expression must be enclosed in braces
-    pub fn dummy_const_arg_needs_braces(&self, mut err: Diag<'a>, span: Span) -> GenericArg {
+    pub(super) fn dummy_const_arg_needs_braces(&self, mut err: Diag<'a>, span: Span) -> GenericArg {
         err.multipart_suggestion(
             "expressions must be enclosed in braces to be used as const generic \
              arguments",
@@ -2961,7 +2965,7 @@ impl<'a> Parser<'a> {
     /// * `=====`
     /// * `<<<<<`
     ///
-    pub fn is_vcs_conflict_marker(
+    pub(super) fn is_vcs_conflict_marker(
         &mut self,
         long_kind: &TokenKind,
         short_kind: &TokenKind,
@@ -2981,14 +2985,14 @@ impl<'a> Parser<'a> {
         None
     }
 
-    pub fn recover_vcs_conflict_marker(&mut self) {
+    pub(super) fn recover_vcs_conflict_marker(&mut self) {
         if let Err(err) = self.err_vcs_conflict_marker() {
             err.emit();
             FatalError.raise();
         }
     }
 
-    pub fn err_vcs_conflict_marker(&mut self) -> PResult<'a, ()> {
+    pub(crate) fn err_vcs_conflict_marker(&mut self) -> PResult<'a, ()> {
         let Some(start) = self.conflict_marker(&TokenKind::BinOp(token::Shl), &TokenKind::Lt)
         else {
             return Ok(());

compiler/rustc_parse/src/parser/expr.rs

@@ -431,7 +431,7 @@ impl<'a> Parser<'a> {
     /// The method does not advance the current token.
     ///
     /// Also performs recovery for `and` / `or` which are mistaken for `&&` and `||` respectively.
-    pub fn check_assoc_op(&self) -> Option<Spanned<AssocOp>> {
+    pub(super) fn check_assoc_op(&self) -> Option<Spanned<AssocOp>> {
         let (op, span) = match (AssocOp::from_token(&self.token), self.token.ident()) {
             // When parsing const expressions, stop parsing when encountering `>`.
             (
@@ -1006,7 +1006,11 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub fn parse_dot_suffix_expr(&mut self, lo: Span, base: P<Expr>) -> PResult<'a, P<Expr>> {
+    pub(super) fn parse_dot_suffix_expr(
+        &mut self,
+        lo: Span,
+        base: P<Expr>,
+    ) -> PResult<'a, P<Expr>> {
         // At this point we've consumed something like `expr.` and `self.token` holds the token
         // after the dot.
         match self.token.uninterpolate().kind {

compiler/rustc_parse/src/parser/item.rs

@@ -2265,7 +2265,7 @@ pub(crate) struct FnParseMode {
     ///     to true.
     ///   * The span is from Edition 2015. In particular, you can get a
     ///     2015 span inside a 2021 crate using macros.
-    pub req_name: ReqName,
+    pub(super) req_name: ReqName,
     /// If this flag is set to `true`, then plain, semicolon-terminated function
     /// prototypes are not allowed here.
     ///
@@ -2284,7 +2284,7 @@ pub(crate) struct FnParseMode {
     /// This field should only be set to false if the item is inside of a trait
     /// definition or extern block. Within an impl block or a module, it should
     /// always be set to true.
-    pub req_body: bool,
+    pub(super) req_body: bool,
 }
 
 /// Parsing of functions and methods.

compiler/rustc_parse/src/parser/mod.rs

@@ -11,14 +11,13 @@ mod stmt;
 mod ty;
 
 use crate::lexer::UnmatchedDelim;
-pub use attr_wrapper::AttrWrapper;
+use attr_wrapper::AttrWrapper;
 pub use diagnostics::AttemptLocalParseRecovery;
 pub(crate) use expr::ForbiddenLetReason;
 pub(crate) use item::FnParseMode;
 pub use pat::{CommaRecoveryMode, RecoverColon, RecoverComma};
-pub use path::PathStyle;
+use path::PathStyle;
 
-use core::fmt;
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter, IdentIsRaw, Nonterminal, Token, TokenKind};
 use rustc_ast::tokenstream::{AttributesData, DelimSpacing, DelimSpan, Spacing};
@@ -37,7 +36,7 @@ use rustc_session::parse::ParseSess;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use std::ops::Range;
-use std::{mem, slice};
+use std::{fmt, mem, slice};
 use thin_vec::ThinVec;
 use tracing::debug;
 
@@ -146,7 +145,7 @@ pub struct Parser<'a> {
     /// The current token.
     pub token: Token,
     /// The spacing for the current token.
-    pub token_spacing: Spacing,
+    token_spacing: Spacing,
     /// The previous token.
     pub prev_token: Token,
     pub capture_cfg: bool,
@@ -187,7 +186,7 @@ pub struct Parser<'a> {
     current_closure: Option<ClosureSpans>,
     /// Whether the parser is allowed to do recovery.
     /// This is disabled when parsing macro arguments, see #103534
-    pub recovery: Recovery,
+    recovery: Recovery,
 }
 
 // This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure
@@ -197,10 +196,10 @@ rustc_data_structures::static_assert_size!(Parser<'_>, 264);
 
 /// Stores span information about a closure.
 #[derive(Clone, Debug)]
-pub struct ClosureSpans {
-    pub whole_closure: Span,
-    pub closing_pipe: Span,
-    pub body: Span,
+struct ClosureSpans {
+    whole_closure: Span,
+    closing_pipe: Span,
+    body: Span,
 }
 
 /// Indicates a range of tokens that should be replaced by
@@ -220,13 +219,13 @@ pub struct ClosureSpans {
 /// the first macro inner attribute to invoke a proc-macro).
 /// When create a `TokenStream`, the inner attributes get inserted
 /// into the proper place in the token stream.
-pub type ReplaceRange = (Range<u32>, Vec<(FlatToken, Spacing)>);
+type ReplaceRange = (Range<u32>, Vec<(FlatToken, Spacing)>);
 
 /// Controls how we capture tokens. Capturing can be expensive,
 /// so we try to avoid performing capturing in cases where
 /// we will never need an `AttrTokenStream`.
 #[derive(Copy, Clone, Debug)]
-pub enum Capturing {
+enum Capturing {
     /// We aren't performing any capturing - this is the default mode.
     No,
     /// We are capturing tokens
@@ -374,13 +373,13 @@ pub enum FollowedByType {
 }
 
 #[derive(Copy, Clone, Debug)]
-pub enum Trailing {
+enum Trailing {
     No,
     Yes,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum TokenDescription {
+pub(super) enum TokenDescription {
     ReservedIdentifier,
     Keyword,
     ReservedKeyword,
@@ -388,7 +387,7 @@ pub enum TokenDescription {
 }
 
 impl TokenDescription {
-    pub fn from_token(token: &Token) -> Option<Self> {
+    pub(super) fn from_token(token: &Token) -> Option<Self> {
         match token.kind {
             _ if token.is_special_ident() => Some(TokenDescription::ReservedIdentifier),
             _ if token.is_used_keyword() => Some(TokenDescription::Keyword),
@@ -502,7 +501,7 @@ impl<'a> Parser<'a> {
     /// Expect next token to be edible or inedible token. If edible,
     /// then consume it; if inedible, then return without consuming
     /// anything. Signal a fatal error if next token is unexpected.
-    pub fn expect_one_of(
+    fn expect_one_of(
         &mut self,
         edible: &[TokenKind],
         inedible: &[TokenKind],
@@ -572,7 +571,7 @@ impl<'a> Parser<'a> {
     /// the main purpose of this function is to reduce the cluttering of the suggestions list
     /// which using the normal eat method could introduce in some cases.
     #[inline]
-    pub fn eat_noexpect(&mut self, tok: &TokenKind) -> bool {
+    fn eat_noexpect(&mut self, tok: &TokenKind) -> bool {
         let is_present = self.check_noexpect(tok);
         if is_present {
             self.bump()
@@ -1520,7 +1519,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub fn collect_tokens_no_attrs<R: HasAttrs + HasTokens>(
+    fn collect_tokens_no_attrs<R: HasAttrs + HasTokens>(
         &mut self,
         f: impl FnOnce(&mut Self) -> PResult<'a, R>,
     ) -> PResult<'a, R> {
@@ -1541,8 +1540,10 @@ impl<'a> Parser<'a> {
             })
     }
 
-    // debug view of the parser's token stream, up to `{lookahead}` tokens
-    pub fn debug_lookahead(&self, lookahead: usize) -> impl fmt::Debug + '_ {
+    // Debug view of the parser's token stream, up to `{lookahead}` tokens.
+    // Only used when debugging.
+    #[allow(unused)]
+    pub(crate) fn debug_lookahead(&self, lookahead: usize) -> impl fmt::Debug + '_ {
         struct DebugParser<'dbg> {
             parser: &'dbg Parser<'dbg>,
             lookahead: usize,
@@ -1618,7 +1619,7 @@ pub(crate) fn make_unclosed_delims_error(
 /// is then 'parsed' to build up an `AttrTokenStream` with nested
 /// `AttrTokenTree::Delimited` tokens.
 #[derive(Debug, Clone)]
-pub enum FlatToken {
+enum FlatToken {
     /// A token - this holds both delimiter (e.g. '{' and '}')
     /// and non-delimiter tokens
     Token(Token),

compiler/rustc_parse/src/parser/mut_visit/tests.rs

@@ -21,14 +21,12 @@ impl MutVisitor for ToZzIdentMutVisitor {
     }
 }
 
-// Maybe add to `expand.rs`.
-macro_rules! assert_pred {
-    ($pred:expr, $predname:expr, $a:expr , $b:expr) => {{
-        let pred_val = $pred;
+macro_rules! assert_matches_codepattern {
+    ($a:expr , $b:expr) => {{
         let a_val = $a;
         let b_val = $b;
-        if !(pred_val(&a_val, &b_val)) {
-            panic!("expected args satisfying {}, got {} and {}", $predname, a_val, b_val);
+        if !matches_codepattern(&a_val, &b_val) {
+            panic!("expected args satisfying `matches_codepattern`, got {} and {}", a_val, b_val);
         }
     }};
 }
@@ -41,9 +39,7 @@ fn ident_transformation() {
         let mut krate =
             string_to_crate("#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
         zz_visitor.visit_crate(&mut krate);
-        assert_pred!(
-            matches_codepattern,
-            "matches_codepattern",
+        assert_matches_codepattern!(
             print_crate_items(&krate),
             "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string()
         );
@@ -61,9 +57,7 @@ fn ident_transformation_in_defs() {
                 .to_string(),
         );
         zz_visitor.visit_crate(&mut krate);
-        assert_pred!(
-            matches_codepattern,
-            "matches_codepattern",
+        assert_matches_codepattern!(
             print_crate_items(&krate),
             "macro_rules! zz{(zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+))}".to_string()
         );

compiler/rustc_parse/src/parser/path.rs

@@ -20,7 +20,7 @@ use tracing::debug;
 
 /// Specifies how to parse a path.
 #[derive(Copy, Clone, PartialEq)]
-pub enum PathStyle {
+pub(super) enum PathStyle {
     /// In some contexts, notably in expressions, paths with generic arguments are ambiguous
     /// with something else. For example, in expressions `segment < ....` can be interpreted
     /// as a comparison and `segment ( ....` can be interpreted as a function call.

compiler/rustc_parse/src/parser/stmt.rs

@@ -31,7 +31,7 @@ impl<'a> Parser<'a> {
     /// Parses a statement. This stops just before trailing semicolons on everything but items.
     /// e.g., a `StmtKind::Semi` parses to a `StmtKind::Expr`, leaving the trailing `;` unconsumed.
     // Public for rustfmt usage.
-    pub fn parse_stmt(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<Stmt>> {
+    pub(super) fn parse_stmt(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<Stmt>> {
         Ok(self.parse_stmt_without_recovery(false, force_collect).unwrap_or_else(|e| {
             e.emit();
             self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);

compiler/rustc_parse/src/parser/ty.rs

@@ -127,7 +127,7 @@ impl<'a> Parser<'a> {
     /// Parse a type suitable for a field definition.
     /// The difference from `parse_ty` is that this version
     /// allows anonymous structs and unions.
-    pub fn parse_ty_for_field_def(&mut self) -> PResult<'a, P<Ty>> {
+    pub(super) fn parse_ty_for_field_def(&mut self) -> PResult<'a, P<Ty>> {
         if self.can_begin_anon_struct_or_union() {
             self.parse_anon_struct_or_union()
         } else {

compiler/rustc_parse/src/validate_attr.rs

@@ -25,15 +25,21 @@ pub fn check_attr(psess: &ParseSess, attr: &Attribute) {
     match attr_info {
         // `rustc_dummy` doesn't have any restrictions specific to built-in attributes.
         Some(BuiltinAttribute { name, template, .. }) if *name != sym::rustc_dummy => {
-            check_builtin_attribute(psess, attr, *name, *template)
+            match parse_meta(psess, attr) {
+                Ok(meta) => check_builtin_meta_item(psess, &meta, attr.style, *name, *template),
+                Err(err) => {
+                    err.emit();
+                }
+            }
         }
         _ if let AttrArgs::Eq(..) = attr.get_normal_item().args => {
             // All key-value attributes are restricted to meta-item syntax.
-            parse_meta(psess, attr)
-                .map_err(|err| {
+            match parse_meta(psess, attr) {
+                Ok(_) => {}
+                Err(err) => {
                     err.emit();
-                })
-                .ok();
+                }
+            }
         }
         _ => {}
     }
@@ -104,7 +110,7 @@ pub fn parse_meta<'a>(psess: &'a ParseSess, attr: &Attribute) -> PResult<'a, Met
     })
 }
 
-pub fn check_meta_bad_delim(psess: &ParseSess, span: DelimSpan, delim: Delimiter) {
+fn check_meta_bad_delim(psess: &ParseSess, span: DelimSpan, delim: Delimiter) {
     if let Delimiter::Parenthesis = delim {
         return;
     }
@@ -114,7 +120,7 @@ pub fn check_meta_bad_delim(psess: &ParseSess, span: DelimSpan, delim: Delimiter
     });
 }
 
-pub fn check_cfg_attr_bad_delim(psess: &ParseSess, span: DelimSpan, delim: Delimiter) {
+pub(super) fn check_cfg_attr_bad_delim(psess: &ParseSess, span: DelimSpan, delim: Delimiter) {
     if let Delimiter::Parenthesis = delim {
         return;
     }
@@ -134,20 +140,6 @@ fn is_attr_template_compatible(template: &AttributeTemplate, meta: &ast::MetaIte
     }
 }
 
-pub fn check_builtin_attribute(
-    psess: &ParseSess,
-    attr: &Attribute,
-    name: Symbol,
-    template: AttributeTemplate,
-) {
-    match parse_meta(psess, attr) {
-        Ok(meta) => check_builtin_meta_item(psess, &meta, attr.style, name, template),
-        Err(err) => {
-            err.emit();
-        }
-    }
-}
-
 pub fn check_builtin_meta_item(
     psess: &ParseSess,
     meta: &MetaItem,