From d50b0bc437f5ffd0d2c9f843217f8ed098c8d675 Mon Sep 17 00:00:00 2001
From: Jan Maria Matejka <mq@ucw.cz>
Date: Tue, 11 Sep 2018 16:55:41 +0200
Subject: [PATCH] Conf: Show the line:char position where the syntax error
 happens

---
 conf/cf-lex.l      | 6 ++++--
 conf/conf.c        | 1 +
 conf/conf.h        | 4 +++-
 sysdep/unix/main.c | 6 +++---
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index c3154b36..9bbb3660 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -100,6 +100,7 @@ static struct include_file_stack *ifs_head;
 #define YY_INPUT(buf,result,max) result = cf_read_hook(buf, max, ifs->fd);
 #define YY_NO_UNPUT
 #define YY_FATAL_ERROR(msg) cf_error(msg)
+#define YY_USER_ACTION ifs->chno += yyleng; ifs->toklen = yyleng;
 
 static void cf_include(char *arg, int alen);
 static int check_eof(void);
@@ -313,7 +314,7 @@ else: {
 
 {WHITE}+
 
-\n	ifs->lino++;
+\n	ifs->lino++; ifs->chno = 0;
 
 #	BEGIN(COMMENT);
 
@@ -323,13 +324,14 @@ else: {
 
 <COMMENT>\n {
   ifs->lino++;
+  ifs->chno = 0;
   BEGIN(INITIAL);
 }
 
 <COMMENT>.
 
 <CCOMM>\*\/	BEGIN(INITIAL);
-<CCOMM>\n	ifs->lino++;
+<CCOMM>\n	ifs->lino++; ifs->chno = 0;
 <CCOMM>\/\*	cf_error("Comment nesting not supported");
 <CCOMM><<EOF>>	cf_error("Unterminated comment");
 <CCOMM>.
diff --git a/conf/conf.c b/conf/conf.c
index 885e2e7e..8dbefe96 100644
--- a/conf/conf.c
+++ b/conf/conf.c
@@ -512,6 +512,7 @@ cf_error(const char *msg, ...)
   va_end(args);
   new_config->err_msg = cfg_strdup(buf);
   new_config->err_lino = ifs->lino;
+  new_config->err_chno = ifs->chno - ifs->toklen + 1;
   new_config->err_file_name = ifs->file_name;
   cf_lex_unwind();
   longjmp(conf_jmpbuf, 1);
diff --git a/conf/conf.h b/conf/conf.h
index f174d352..5689fb67 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -47,6 +47,7 @@ struct config {
   u32 watchdog_timeout;			/* Watchdog timeout (in seconds, 0 = disabled) */
   char *err_msg;			/* Parser error message */
   int err_lino;				/* Line containing error */
+  int err_chno;				/* Character where the parser stopped */
   char *err_file_name;			/* File name containing error */
   char *file_name;			/* Name of main configuration file */
   int file_fd;				/* File descriptor of main configuration file */
@@ -139,6 +140,8 @@ struct include_file_stack {
   char *file_name;			/* File name */
   int fd;				/* File descriptor */
   int lino;				/* Current line num */
+  int chno;				/* Current char num (on current line) */
+  int toklen;				/* Current token length */
   int depth;				/* Include depth, 0 = cannot include */
 
   struct include_file_stack *prev;	/* Previous record in stack */
@@ -147,7 +150,6 @@ struct include_file_stack {
 
 extern struct include_file_stack *ifs;
 
-
 int cf_lex(void);
 void cf_lex_init(int is_cli, struct config *c);
 void cf_lex_unwind(void);
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index 0912a9c5..d2380501 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -213,7 +213,7 @@ read_config(void)
   if (!unix_read_config(&conf, config_name))
     {
       if (conf->err_msg)
-	die("%s, line %d: %s", conf->err_file_name, conf->err_lino, conf->err_msg);
+	die("%s:%d:%d %s", conf->err_file_name, conf->err_lino, conf->err_chno, conf->err_msg);
       else
 	die("Unable to open configuration file %s: %m", config_name);
     }
@@ -230,7 +230,7 @@ async_config(void)
   if (!unix_read_config(&conf, config_name))
     {
       if (conf->err_msg)
-	log(L_ERR "%s, line %d: %s", conf->err_file_name, conf->err_lino, conf->err_msg);
+	log(L_ERR "%s:%d:%d %s", conf->err_file_name, conf->err_lino, conf->err_chno, conf->err_msg);
       else
 	log(L_ERR "Unable to open configuration file %s: %m", config_name);
       config_free(conf);
@@ -251,7 +251,7 @@ cmd_read_config(char *name)
   if (!unix_read_config(&conf, name))
     {
       if (conf->err_msg)
-	cli_msg(8002, "%s, line %d: %s", conf->err_file_name, conf->err_lino, conf->err_msg);
+	cli_msg(8002, "%s:%d:%d %s", conf->err_file_name, conf->err_lino, conf->err_chno, conf->err_msg);
       else
 	cli_msg(8002, "%s: %m", name);
       config_free(conf);