parse.y: Add comment for `rb_strterm_heredoc_struct.sourceline`

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63974 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/parse.y b/parse.y
index 51f7d3f2f0..094341170b 100644
--- a/parse.y
+++ b/parse.y
@@ -566,7 +566,7 @@ typedef struct rb_strterm_literal_struct {
 } rb_strterm_literal_t;
 
 struct rb_strterm_heredoc_struct {
-    SIGNED_VALUE sourceline;
+    SIGNED_VALUE sourceline; /* lineno of the line that contains `<<"END"` */
     VALUE term;		/* `"END"` of `<<"END"` */
     VALUE lastline;	/* the string of line that contains `<<"END"` */
     union {