C2x strtol binary constant handling: Fix special case "0b"
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Commit Message
Hi Joseph,
While adding C2x support to the strtol, strtoll, strtoul, strtoull
functions in Gnulib, I was glad to see that you have already done
the support in glibc. But I noticed that the glibc implementation
apparently does not handle the input "0b" correctly. The unit test
cases for this special case are:
{
const char input[] = "0b";
char *ptr;
long result;
errno = 0;
result = strtol (input, &ptr, 2);
assert (result == 0L);
assert (ptr == input + 1);
assert (errno == 0);
}
{
const char input[] = "0b";
char *ptr;
long result;
errno = 0;
result = strtol (input, &ptr, 0);
assert (result == 0L);
assert (ptr == input + 1);
assert (errno == 0);
}
and likewise for strtoll, strtoul, strtoull.
Find attached a correction for this. I have tested it in Gnulib (which
has very similar source code as glibc for this functionality), not in
Glibc directly. Therefore, please review thoroughly.
Bruno
Comments
On 16/03/23 12:14, Bruno Haible wrote:
> Hi Joseph,
>
> While adding C2x support to the strtol, strtoll, strtoul, strtoull
> functions in Gnulib, I was glad to see that you have already done
> the support in glibc. But I noticed that the glibc implementation
> apparently does not handle the input "0b" correctly. The unit test
> cases for this special case are:
>
> {
> const char input[] = "0b";
> char *ptr;
> long result;
> errno = 0;
> result = strtol (input, &ptr, 2);
> assert (result == 0L);
> assert (ptr == input + 1);
> assert (errno == 0);
> }
> {
> const char input[] = "0b";
> char *ptr;
> long result;
> errno = 0;
> result = strtol (input, &ptr, 0);
> assert (result == 0L);
> assert (ptr == input + 1);
> assert (errno == 0);
> }
>
> and likewise for strtoll, strtoul, strtoull.
>
> Find attached a correction for this. I have tested it in Gnulib (which
> has very similar source code as glibc for this functionality), not in
> Glibc directly. Therefore, please review thoroughly.
>
> Bruno
Could you also add these testscase on strtol tests ?
From c11497ab8117f27680537abccda211c5be560452 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Thu, 16 Mar 2023 15:25:45 +0100
Subject: [PATCH] C2x strtol binary constant handling: Fix special case "0b".
This is a follow-up to commit 64924422a99690d147a166b4de3103f3bf3eaf6c
by Joseph Myers.
The special case of input "0b" was not handled correctly. Test cases:
{
const char input[] = "0b";
char *ptr;
long result;
errno = 0;
result = strtol (input, &ptr, 2);
assert (result == 0L);
assert (ptr == input + 1);
assert (errno == 0);
}
{
const char input[] = "0b";
char *ptr;
long result;
errno = 0;
result = strtol (input, &ptr, 0);
assert (result == 0L);
assert (ptr == input + 1);
assert (errno == 0);
}
* stdlib/strtol_l.c (INTERNAL (__strtol_l)): Handle the binary integers
also in the 'noconv' part of the code.
---
stdlib/strtol_l.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
@@ -526,11 +526,15 @@ INTERNAL (__strtol_l) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
noconv:
/* We must handle a special case here: the base is 0 or 16 and the
first two characters are '0' and 'x', but the rest are no
- hexadecimal digits. This is no error case. We return 0 and
- ENDPTR points to the `x`. */
+ hexadecimal digits. Likewise when the base is 0 or 2 and the
+ first two characters are '0' and 'b', but the rest are no binary
+ digits. This is no error case. We return 0 and ENDPTR points to
+ the 'x' or 'b'. */
if (endptr != NULL)
{
- if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
+ if (save - nptr >= 2
+ && (TOUPPER (save[-1]) == L_('X')
+ || (bin_cst && TOUPPER (save[-1]) == L_('B')))
&& save[-2] == L_('0'))
*endptr = (STRING_TYPE *) &save[-1];
else
--
2.34.1