select: add message about 'help' field to get more help on each error hit during...

Inform about 'help' to get more help about selection fields and operators
after each syntax error hit:

  "Use 'help' for selection to get more help."

diff --git a/libdm/libdm-report.c b/libdm/libdm-report.c
index 67f63d5dd747805aa468790a2f32d4dd0a0f6084..957a4c918cf91f8f450f1d787bf722ba27fcf070 100644 (file)
--- a/libdm/libdm-report.c
+++ b/libdm/libdm-report.c
@@ -2396,7 +2396,8 @@ out_reserved_values:
        log_warn(" ");
 }
 
-static char _sel_syntax_error_at_msg[] = "Selection syntax error at '%s'.";
+static const char _sel_syntax_error_at_msg[] = "Selection syntax error at '%s'.";
+static const char _sel_help_ref_msg[] = "Use \'help\' for selection to get more help.";
 
 /*
  * Selection parser
@@ -2460,6 +2461,8 @@ static struct selection_node *_parse_selection(struct dm_report *rh,
                        c = we[0];
                        tmp = (char *) we;
                        tmp[0] = '\0';
+                       _display_fields(rh, 0, 1);
+                       log_warn(" ");
                        log_error("Selection field is uncomparable: %s.", ws);
                        tmp[0] = c;
                        goto bad;
@@ -2522,6 +2525,7 @@ static struct selection_node *_parse_selection(struct dm_report *rh,
        return sn;
 bad:
        log_error(_sel_syntax_error_at_msg, s);
+       log_error(_sel_help_ref_msg);
        *next = s;
        return NULL;
 }
@@ -2695,6 +2699,7 @@ struct dm_report *dm_report_init_with_selection(uint32_t *report_types,
        if (*next) {
                log_error("Expecting logical operator");
                log_error(_sel_syntax_error_at_msg, next);
+               log_error(_sel_help_ref_msg);
                goto error;
        }