Use a span from the correct file for the inner span of a module

This basically only affects modules which are empty (or only contain comments).

Closes #26755

3 files changed, 24 insertions, 12 deletions

diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index b6a3788dacc..621335ecd97 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -231,6 +231,7 @@ impl<'a> StringReader<'a> {
             None => {
                 if self.is_eof() {
                     self.peek_tok = token::Eof;
+                    self.peek_span = codemap::mk_sp(self.filemap.end_pos, self.filemap.end_pos);
                 } else {
                     let start_bytepos = self.last_pos;
                     self.peek_tok = self.next_token_inner();
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index d6c28d41447..34a63fc92fe 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -11,7 +11,7 @@
 //! The main parser interface
 
 use ast;
-use codemap::{Span, CodeMap, FileMap};
+use codemap::{self, Span, CodeMap, FileMap};
 use diagnostic::{SpanHandler, Handler, Auto, FatalError};
 use parse::attr::ParserAttr;
 use parse::parser::Parser;
@@ -203,7 +203,14 @@ pub fn new_sub_parser_from_file<'a>(sess: &'a ParseSess,
 pub fn filemap_to_parser<'a>(sess: &'a ParseSess,
                              filemap: Rc<FileMap>,
                              cfg: ast::CrateConfig) -> Parser<'a> {
-    tts_to_parser(sess, filemap_to_tts(sess, filemap), cfg)
+    let end_pos = filemap.end_pos;
+    let mut parser = tts_to_parser(sess, filemap_to_tts(sess, filemap), cfg);
+
+    if parser.token == token::Eof && parser.span == codemap::DUMMY_SP {
+        parser.span = codemap::mk_sp(end_pos, end_pos);
+    }
+
+    parser
 }
 
 // must preserve old name for now, because quote! from the *existing*
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 28802d323c6..db1b2489f1d 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4824,8 +4824,14 @@ impl<'a> Parser<'a> {
             return Err(self.fatal(&format!("expected item, found `{}`", token_str)));
         }
 
+        let hi = if self.span == codemap::DUMMY_SP {
+            inner_lo
+        } else {
+            self.span.lo
+        };
+
         Ok(ast::Mod {
-            inner: mk_sp(inner_lo, self.span.lo),
+            inner: mk_sp(inner_lo, hi),
             items: items
         })
     }
@@ -4869,8 +4875,7 @@ impl<'a> Parser<'a> {
 
     fn push_mod_path(&mut self, id: Ident, attrs: &[Attribute]) {
         let default_path = self.id_to_interned_str(id);
-        let file_path = match ::attr::first_attr_value_str_by_name(attrs,
-                                                                   "path") {
+        let file_path = match ::attr::first_attr_value_str_by_name(attrs, "path") {
             Some(d) => d,
             None => default_path,
         };
@@ -5003,13 +5008,12 @@ impl<'a> Parser<'a> {
         included_mod_stack.push(path.clone());
         drop(included_mod_stack);
 
-        let mut p0 =
-            new_sub_parser_from_file(self.sess,
-                                     self.cfg.clone(),
-                                     &path,
-                                     owns_directory,
-                                     Some(name),
-                                     id_sp);
+        let mut p0 = new_sub_parser_from_file(self.sess,
+                                              self.cfg.clone(),
+                                              &path,
+                                              owns_directory,
+                                              Some(name),
+                                              id_sp);
         let mod_inner_lo = p0.span.lo;
         let mod_attrs = p0.parse_inner_attributes();
         let m0 = try!(p0.parse_mod_items(&token::Eof, mod_inner_lo));