Remove stream_to_parser.

It's a zero-value wrapper of `Parser::new`.

compiler/rustc_builtin_macros/src/cfg_eval.rs

@@ -196,7 +196,7 @@ impl CfgEval<'_, '_> {
         // Re-parse the tokens, setting the `capture_cfg` flag to save extra information
         // to the captured `AttrTokenStream` (specifically, we capture
         // `AttrTokenTree::AttributesData` for all occurrences of `#[cfg]` and `#[cfg_attr]`)
-        let mut parser = rustc_parse::stream_to_parser(&self.cfg.sess.psess, orig_tokens, None);
+        let mut parser = Parser::new(&self.cfg.sess.psess, orig_tokens, None);
         parser.capture_cfg = true;
         match parse_annotatable_with(&mut parser) {
             Ok(a) => annotatable = a,

compiler/rustc_expand/src/base.rs

@@ -15,7 +15,7 @@ use rustc_data_structures::sync::{self, Lrc};
 use rustc_errors::{DiagCtxt, ErrorGuaranteed, PResult};
 use rustc_feature::Features;
 use rustc_lint_defs::{BufferedEarlyLint, RegisteredTools};
-use rustc_parse::{parser, MACRO_ARGUMENTS};
+use rustc_parse::{parser::Parser, MACRO_ARGUMENTS};
 use rustc_session::config::CollapseMacroDebuginfo;
 use rustc_session::{parse::ParseSess, Limit, Session};
 use rustc_span::def_id::{CrateNum, DefId, LocalDefId};
@@ -1149,8 +1149,8 @@ impl<'a> ExtCtxt<'a> {
     pub fn monotonic_expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> {
         expand::MacroExpander::new(self, true)
     }
-    pub fn new_parser_from_tts(&self, stream: TokenStream) -> parser::Parser<'a> {
-        rustc_parse::stream_to_parser(&self.sess.psess, stream, MACRO_ARGUMENTS)
+    pub fn new_parser_from_tts(&self, stream: TokenStream) -> Parser<'a> {
+        Parser::new(&self.sess.psess, stream, MACRO_ARGUMENTS)
     }
     pub fn source_map(&self) -> &'a SourceMap {
         self.sess.psess.source_map()

compiler/rustc_expand/src/proc_macro.rs

@@ -6,7 +6,7 @@ use rustc_ast as ast;
 use rustc_ast::ptr::P;
 use rustc_ast::tokenstream::TokenStream;
 use rustc_errors::ErrorGuaranteed;
-use rustc_parse::parser::ForceCollect;
+use rustc_parse::parser::{ForceCollect, Parser};
 use rustc_session::config::ProcMacroExecutionStrategy;
 use rustc_span::profiling::SpannedEventArgRecorder;
 use rustc_span::Span;
@@ -154,8 +154,7 @@ impl MultiItemModifier for DeriveProcMacro {
         };
 
         let error_count_before = ecx.dcx().err_count();
-        let mut parser =
-            rustc_parse::stream_to_parser(&ecx.sess.psess, stream, Some("proc-macro derive"));
+        let mut parser = Parser::new(&ecx.sess.psess, stream, Some("proc-macro derive"));
         let mut items = vec![];
 
         loop {

compiler/rustc_expand/src/proc_macro_server.rs

@@ -13,6 +13,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Diag, ErrorGuaranteed, MultiSpan, PResult};
 use rustc_parse::lexer::nfc_normalize;
+use rustc_parse::parser::Parser;
 use rustc_parse::source_str_to_stream;
 use rustc_session::parse::ParseSess;
 use rustc_span::def_id::CrateNum;
@@ -553,11 +554,7 @@ impl server::TokenStream for Rustc<'_, '_> {
     fn expand_expr(&mut self, stream: &Self::TokenStream) -> Result<Self::TokenStream, ()> {
         // Parse the expression from our tokenstream.
         let expr: PResult<'_, _> = try {
-            let mut p = rustc_parse::stream_to_parser(
-                self.psess(),
-                stream.clone(),
-                Some("proc_macro expand expr"),
-            );
+            let mut p = Parser::new(self.psess(), stream.clone(), Some("proc_macro expand expr"));
             let expr = p.parse_expr()?;
             if p.token != token::Eof {
                 p.unexpected()?;

compiler/rustc_parse/src/lexer/tokentrees.rs

@@ -2,6 +2,7 @@ use super::diagnostics::report_suspicious_mismatch_block;
 use super::diagnostics::same_indentation_level;
 use super::diagnostics::TokenTreeDiagInfo;
 use super::{StringReader, UnmatchedDelim};
+use crate::Parser;
 use rustc_ast::token::{self, Delimiter, Token};
 use rustc_ast::tokenstream::{DelimSpacing, DelimSpan, Spacing, TokenStream, TokenTree};
 use rustc_ast_pretty::pprust::token_to_string;
@@ -231,7 +232,7 @@ impl<'psess, 'src> TokenTreesReader<'psess, 'src> {
     ) -> Vec<PErr<'psess>> {
         // If there are unclosed delims, see if there are diff markers and if so, point them
         // out instead of complaining about the unclosed delims.
-        let mut parser = crate::stream_to_parser(self.string_reader.psess, tts, None);
+        let mut parser = Parser::new(self.string_reader.psess, tts, None);
         let mut diff_errs = vec![];
         // Suggest removing a `{` we think appears in an `if`/`while` condition.
         // We want to suggest removing a `{` only if we think we're in an `if`/`while` condition,

compiler/rustc_parse/src/lib.rs

@@ -123,7 +123,7 @@ fn maybe_source_file_to_parser(
 ) -> Result<Parser<'_>, Vec<Diag<'_>>> {
     let end_pos = source_file.end_position();
     let stream = maybe_source_file_to_stream(psess, source_file, None)?;
-    let mut parser = stream_to_parser(psess, stream, None);
+    let mut parser = Parser::new(psess, stream, None);
     if parser.token == token::Eof {
         parser.token.span = Span::new(end_pos, end_pos, parser.token.span.ctxt(), None);
     }
@@ -168,15 +168,6 @@ fn maybe_source_file_to_stream<'psess>(
     lexer::lex_token_trees(psess, src.as_str(), source_file.start_pos, override_span)
 }
 
-/// Given a stream and the `ParseSess`, produces a parser.
-pub fn stream_to_parser<'a>(
-    psess: &'a ParseSess,
-    stream: TokenStream,
-    subparser_name: Option<&'static str>,
-) -> Parser<'a> {
-    Parser::new(psess, stream, subparser_name)
-}
-
 /// Runs the given subparser `f` on the tokens of the given `attr`'s item.
 pub fn parse_in<'a, T>(
     psess: &'a ParseSess,

src/tools/rustfmt/src/parse/macros/mod.rs

@@ -2,7 +2,7 @@ use rustc_ast::token::{Delimiter, NonterminalKind, TokenKind};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::{ast, ptr};
 use rustc_parse::parser::{ForceCollect, Parser, Recovery};
-use rustc_parse::{stream_to_parser, MACRO_ARGUMENTS};
+use rustc_parse::MACRO_ARGUMENTS;
 use rustc_session::parse::ParseSess;
 use rustc_span::symbol::{self, kw};
 use rustc_span::Symbol;
@@ -15,7 +15,7 @@ pub(crate) mod cfg_if;
 pub(crate) mod lazy_static;
 
 fn build_stream_parser<'a>(psess: &'a ParseSess, tokens: TokenStream) -> Parser<'a> {
-    stream_to_parser(psess, tokens, MACRO_ARGUMENTS).recovery(Recovery::Forbidden)
+    Parser::new(psess, tokens, MACRO_ARGUMENTS).recovery(Recovery::Forbidden)
 }
 
 fn build_parser<'a>(context: &RewriteContext<'a>, tokens: TokenStream) -> Parser<'a> {