[src/trunk]: src/usr.bin/printf Change octal and hex parsing to not use strto...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3426872d9cf5
branches:  trunk
changeset: 982542:3426872d9cf5
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Apr 16 15:10:18 2021 +0000

description:
Change octal and hex parsing to not use strtoul so that they don't handle
'-'. From Martijn van Duren.
Also add a warning if the conversion fails (like the gnu printf does)

diffstat:

 usr.bin/printf/printf.c |  44 ++++++++++++++++++++++++++------------------
 1 files changed, 26 insertions(+), 18 deletions(-)

diffs (86 lines):

diff -r d07697d7f398 -r 3426872d9cf5 usr.bin/printf/printf.c
--- a/usr.bin/printf/printf.c   Fri Apr 16 13:02:47 2021 +0000
+++ b/usr.bin/printf/printf.c   Fri Apr 16 15:10:18 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: printf.c,v 1.50 2019/07/22 17:34:31 kre Exp $  */
+/*     $NetBSD: printf.c,v 1.51 2021/04/16 15:10:18 christos Exp $     */
 
 /*
  * Copyright (c) 1989, 1993
@@ -41,7 +41,7 @@
 #if 0
 static char sccsid[] = "@(#)printf.c   8.2 (Berkeley) 3/22/95";
 #else
-__RCSID("$NetBSD: printf.c,v 1.50 2019/07/22 17:34:31 kre Exp $");
+__RCSID("$NetBSD: printf.c,v 1.51 2021/04/16 15:10:18 christos Exp $");
 #endif
 #endif /* not lint */
 
@@ -118,6 +118,10 @@
                error = asprintf(cpp, f, func); \
 }
 
+#define isodigit(c)    ((c) >= '0' && (c) <= '7')
+#define octtobin(c)    (char)((c) - '0')
+#define check(c, a)    (c) >= (a) && (c) <= (a) + 5 ? (char)((c) - (a) + 10)
+#define hextobin(c)    (check(c, 'a') : check(c, 'A') : (char)((c) - '0'))
 #ifdef main
 int main(int, char *[]);
 #endif
@@ -482,9 +486,9 @@
 static char *
 conv_escape(char *str, char *conv_ch, int quiet)
 {
-       char value;
-       char ch;
-       char num_buf[4], *num_end;
+       char value = 0;
+       char ch, *begin;
+       int c;
 
        ch = *str++;
 
@@ -499,13 +503,11 @@
 
        case '0': case '1': case '2': case '3':
        case '4': case '5': case '6': case '7':
-               num_buf[0] = ch;
-               ch = str[0];
-               num_buf[1] = ch;
-               num_buf[2] = (char)(ch != '\0' ? str[1] : '\0');
-               num_buf[3] = '\0';
-               value = (char)strtoul(num_buf, &num_end, 8);
-               str += num_end  - (num_buf + 1);
+               str--;
+               for (c = 3; c-- && isodigit(*str); str++) {
+                       value <<= 3;
+                       value += octtobin(*str);
+               }
                break;
 
        case 'x':
@@ -515,12 +517,18 @@
                 * way to detect the end of the constant.
                 * Supporting 2 byte constants is a compromise.
                 */
-               ch = str[0];
-               num_buf[0] = ch;
-               num_buf[1] = (char)(ch != '\0' ? str[1] : '\0');
-               num_buf[2] = '\0';
-               value = (char)strtoul(num_buf, &num_end, 16);
-               str += num_end - num_buf;
+               begin = str;
+               for (c = 2; c-- && isxdigit((unsigned char)*str); str++) {
+                       value <<= 4;
+                       const char d = hextobin(*str);
+                       value += d;
+               }
+               if (str == begin) {
+                       if (!quiet)
+                               warnx("\\x%s: missing hexadecimal number "
+                                   "in escape", begin);
+                       rval = 1;
+               }
                break;
 
        case '\\':      value = '\\';   break;  /* backslash */