kconfig: use yylineno option instead of manual lineno increments

Tracking the line number by hand is error-prone since you need to
increment it in every \n matching pattern.

If '%option yylineno' is set, flex defines 'yylineno' to contain the
current line number and automatically updates it each time it reads a
\n character.  This is much more convenient although the lexer does
not initializes yylineno, so you need to set it to 1 each time you
start reading a new file, and restore it you go back to the previous
file.

I tested this with DEBUG_PARSE, and confirmed the same dump message
was produced.

I removed the perf-report option.  Otherwise, I see the following
message:
  %option yylineno entails a performance penalty ONLY on rules that
  can match newline characters

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

2 files changed, 10 insertions, 11 deletions

diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index 2d5ec2d0e952..f4394af6e4b8 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -68,6 +68,7 @@ struct kconf_id {
         enum symbol_type stype;
 };
 
+extern int yylineno;
 void zconfdump(FILE *out);
 void zconf_starthelp(void);
 FILE *zconf_fopen(const char *name);
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 29b5d338d6bc..045093d827e1 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -1,5 +1,5 @@
 %option nostdinit noyywrap never-interactive full ecs
-%option 8bit nodefault perf-report perf-report
+%option 8bit nodefault yylineno
 %option noinput
 %x COMMAND HELP STRING PARAM
 %{
@@ -83,7 +83,6 @@ n	[A-Za-z0-9_-]
 
 [ \t]*#.*\n     |
 [ \t]*\n        {
-        current_file->lineno++;
         return T_EOL;
 }
 [ \t]*#.*
@@ -104,7 +103,7 @@ n	[A-Za-z0-9_-]
                 const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
                 BEGIN(PARAM);
                 current_pos.file = current_file;
-                current_pos.lineno = current_file->lineno;
+                current_pos.lineno = yylineno;
                 if (id && id->flags & TF_COMMAND) {
                         yylval.id = id;
                         return id->token;
@@ -116,7 +115,6 @@ n	[A-Za-z0-9_-]
         .       warn_ignored_character(*yytext);
         \n      {
                 BEGIN(INITIAL);
-                current_file->lineno++;
                 return T_EOL;
         }
 }
@@ -138,7 +136,7 @@ n	[A-Za-z0-9_-]
                 new_string();
                 BEGIN(STRING);
         }
-        \n      BEGIN(INITIAL); current_file->lineno++; return T_EOL;
+        \n      BEGIN(INITIAL); return T_EOL;
         ({n}|[/.])+     {
                 const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
                 if (id && id->flags & TF_PARAM) {
@@ -150,7 +148,7 @@ n	[A-Za-z0-9_-]
                 return T_WORD;
         }
         #.*     /* comment */
-        \\\n    current_file->lineno++;
+        \\\n    ;
         [[:blank:]]+
         .       warn_ignored_character(*yytext);
         <<EOF>> {
@@ -187,7 +185,6 @@ n	[A-Za-z0-9_-]
                 fprintf(stderr,
                         "%s:%d:warning: multi-line strings not supported\n",
                         zconf_curname(), zconf_lineno());
-                current_file->lineno++;
                 BEGIN(INITIAL);
                 return T_EOL;
         }
@@ -220,12 +217,10 @@ n	[A-Za-z0-9_-]
                 }
         }
         [ \t]*\n/[^ \t\n] {
-                current_file->lineno++;
                 zconf_endhelp();
                 return T_HELPTEXT;
         }
         [ \t]*\n        {
-                current_file->lineno++;
                 append_string("\n", 1);
         }
         [^ \t\n].* {
@@ -304,7 +299,7 @@ void zconf_initscan(const char *name)
         memset(current_buf, 0, sizeof(*current_buf));
 
         current_file = file_lookup(name);
-        current_file->lineno = 1;
+        yylineno = 1;
 }
 
 void zconf_nextfile(const char *name)
@@ -325,6 +320,7 @@ void zconf_nextfile(const char *name)
         buf->parent = current_buf;
         current_buf = buf;
 
+        current_file->lineno = yylineno;
         file->parent = current_file;
 
         for (iter = current_file; iter; iter = iter->parent) {
@@ -343,7 +339,7 @@ void zconf_nextfile(const char *name)
                 }
         }
 
-        file->lineno = 1;
+        yylineno = 1;
         current_file = file;
 }
 
@@ -352,6 +348,8 @@ static void zconf_endfile(void)
         struct buffer *parent;
 
         current_file = current_file->parent;
+        if (current_file)
+                yylineno = current_file->lineno;
 
         parent = current_buf->parent;
         if (parent) {