Declaration of crypt
Ken Brown
kbrown@cornell.edu
Thu Jun 9 12:05:00 GMT 2016
On 6/9/2016 5:00 AM, Corinna Vinschen wrote:
> Hi Ken,
>
> On Jun 8 17:18, Ken Brown wrote:
>> According to Posix, including <unistd.h> should bring in the declaration of
>> crypt. The glibc and FreeBSD headers are consistent with this, but Cygwin's
>> aren't.
>>
>> $ cat test.c
>> #include <unistd.h>
>>
>> int
>> main (void)
>> {
>> const char *key = NULL;
>> const char *salt = NULL;
>> crypt (key, salt);
>> }
>>
>> $ gcc -c test.c
>> test.c: In function âmainâ:
>> test.c:8:3: warning: implicit declaration of function âcryptâ
>> [-Wimplicit-function-declaration]
>> crypt (key, salt);
>> ^
>>
>> The attached patch is one way to fix this. It means that cygwin-devel would
>> have to require libcrypt-devel.
>>
>> I'm not sure if I used the right feature-test macro in the patch. It's
>> marked XSI by Posix, but using __XSI_VISIBLE didn't work.
>
> What do you mean by "didn't work"? __XSI_VISIBLE should be the right
> thing to use. Your application would have to define, e.g.,
> _XOPEN_SOURCE before including the file.
Ah, that's what I missed. I tried defining __XSI_VISIBLE in the test
file, and I still got the implicit declaration warning. I see now,
reading /usr/include/sys/features.h, that __XSI_VISIBLE is a private
macro and shouldn't have been used in my test.
> Another point is the && defined(__CYGWIN__). This should go away.
> We're trying to make the headers more standards compatible without
> going into too much detial what targat provides which function.
I wasn't sure that <crypt.h> was portable to all newlib targets.
>> P.S. Is cygwin-patches OK for this sort of thing, or should I have sent it
>> to the newlib list?
>
> Ideally to the newlib list, but no worries :)
OK, I'll do that next time.
Revised patch attached.
Ken
-------------- next part --------------
From cb8c2454618c1d862b926d61ac95411b384d0414 Mon Sep 17 00:00:00 2001
From: Ken Brown <kbrown@cornell.edu>
Date: Wed, 8 Jun 2016 17:04:06 -0400
Subject: [PATCH] Make <unistd.h> declare crypt
This is mandated by Posix and is done by the glibc and FreeBSD headers.
---
newlib/libc/include/sys/unistd.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/newlib/libc/include/sys/unistd.h b/newlib/libc/include/sys/unistd.h
index ef00575..0cbb5de 100644
--- a/newlib/libc/include/sys/unistd.h
+++ b/newlib/libc/include/sys/unistd.h
@@ -31,6 +31,9 @@ int _EXFUN(close, (int __fildes ));
#if __POSIX_VISIBLE >= 199209
size_t _EXFUN(confstr, (int __name, char *__buf, size_t __len));
#endif
+#if __XSI_VISIBLE
+#include <crypt.h>
+#endif
#if __XSI_VISIBLE && __XSI_VISIBLE < 700
char * _EXFUN(ctermid, (char *__s ));
#endif
--
2.8.3
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