kconfig: warn no new line at end of file

It would be nice to warn if a new line is missing at end of file.

We could do this by checkpatch.pl for arbitrary files, but new line
is rather essential as a statement terminator in Kconfig.

The warning message looks like this:

  kernel/Kconfig.preempt:60:warning: no new line at end of file

Currently, kernel/Kconfig.preempt is the only file with no new line
at end of file. Fix it.

I know there are some false negative cases. For example, no warning
is displayed when the last line contains some whitespaces/comments,
but no new line. Yet, this commit works well for most cases.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 9038e9736bf0..8e856f9e6da9 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -261,6 +261,10 @@ n	[A-Za-z0-9_-]
 <<EOF>> {
         BEGIN(INITIAL);
 
+        if (prev_token != T_EOL && prev_token != T_HELPTEXT)
+                fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
+                        current_file->name, yylineno);
+
         if (current_file) {
                 zconf_endfile();
                 return T_EOL;