Strip frontmatter in fewer places

Author: fmease

src/parse/parser.rs

@@ -3,6 +3,7 @@ use std::path::{Path, PathBuf};
 
 use rustc_ast::{ast, attr};
 use rustc_errors::Diag;
+use rustc_parse::lexer::StripTokens;
 use rustc_parse::parser::Parser as RawParser;
 use rustc_parse::{exp, new_parser_from_file, new_parser_from_source_str, unwrap_or_emit_fatal};
 use rustc_span::{Span, sym};
@@ -64,11 +65,14 @@ impl<'a> ParserBuilder<'a> {
         input: Input,
     ) -> Result<RawParser<'a>, Vec<Diag<'a>>> {
         match input {
-            Input::File(ref file) => new_parser_from_file(psess, file, None),
+            Input::File(ref file) => {
+                new_parser_from_file(psess, file, StripTokens::ShebangAndFrontmatter, None)
+            }
             Input::Text(text) => new_parser_from_source_str(
                 psess,
                 rustc_span::FileName::Custom("stdin".to_owned()),
                 text,
+                StripTokens::ShebangAndFrontmatter,
             ),
         }
     }
@@ -104,8 +108,12 @@ impl<'a> Parser<'a> {
         span: Span,
     ) -> Result<(ast::AttrVec, ThinVec<Box<ast::Item>>, Span), ParserError> {
         let result = catch_unwind(AssertUnwindSafe(|| {
-            let mut parser =
-                unwrap_or_emit_fatal(new_parser_from_file(psess.inner(), path, Some(span)));
+            let mut parser = unwrap_or_emit_fatal(new_parser_from_file(
+                psess.inner(),
+                path,
+                StripTokens::ShebangAndFrontmatter,
+                Some(span),
+            ));
             match parser.parse_mod(exp!(Eof)) {
                 Ok((a, i, spans)) => Some((a, i, spans.inner_span)),
                 Err(e) => {