1 files changed, 4 insertions, 3 deletions

diff --git a/stc/cfmt.h b/stc/cfmt.h
index 0e838bf6..843e1b12 100644
--- a/stc/cfmt.h
+++ b/stc/cfmt.h
@@ -153,6 +153,7 @@ _cfmt_printf(int s, const char* fmt, ...) {
 STC_DEF char *

 _cfmt_conv(int nargs, const char *fmt, ...) {

     char *fmt2 = (char *) malloc(strlen(fmt)*2 + 1), *p = fmt2, *f, ch;

+    const char *fmt0 = fmt;

     int n = 0;

     va_list args;

     va_start(args, fmt);

@@ -162,7 +163,7 @@ _cfmt_conv(int nargs, const char *fmt, ...) {
             *p++ = *fmt++;

             if (*fmt == '%') break;

             if (++n > nargs) {

-                fprintf(stderr, "error: c_printf(): missing argument\n");

+                fprintf(stderr, "ERROR: c_printf() missing argument(%d): %s\n", n, fmt0);

                 break;

             }

             f = va_arg(args, char *);

@@ -181,7 +182,7 @@ _cfmt_conv(int nargs, const char *fmt, ...) {
             if (fmt[1] == '{') { ++fmt; break; }

             if (fmt[1] == ':' || fmt[1] == '}') {

                 if (++n > nargs) {

-                    fprintf(stderr, "error: c_printf(): missing argument\n");

+                    fprintf(stderr, "ERROR: c_printf() missing argument(%d): %s\n", n, fmt0);

                     break;

                 }

                 *p++ = '%';

@@ -200,7 +201,7 @@ _cfmt_conv(int nargs, const char *fmt, ...) {
     } while (ch);

     va_end(args);

     if (n < nargs)

-        fprintf(stderr, "warning: c_printf(): superfluous argument(s)\n");

+        fprintf(stderr, "WARNING: c_printf() %d superfluous argument(s): %s\n", nargs - n, fmt0);

     return fmt2;

 }