cstdlib not able to resolve using ::wcstombs

Question

I upgraded my system to fedora 33 after which I observed that stdlib.h was not able to resolve some data structures:

In file included from /usr/include/c++/10/cstdlib:75,
                 from /usr/include/c++/10/ext/string_conversions.h:41,
                 from /usr/include/c++/10/bits/basic_string.h:6545,
                 from /usr/include/c++/10/string:55,
                 from /home/ideepika/ceph5/ceph/src/rocksdb/include/rocksdb/cache.h:27,
                 from /home/ideepika/ceph5/ceph/src/rocksdb/cache/clock_cache.h:12,
                 from /home/ideepika/ceph5/ceph/src/rocksdb/cache/clock_cache.cc:10:
/usr/include/stdlib.h:935:5: error: expected initializer before ‘__attr_access’
  935 |     __attr_access ((__read_only__, 2));
      |     ^~~~~~~~~~~~~
/usr/include/stdlib.h:940:3: error: expected initializer before ‘__attr_access’
  940 |   __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2));
      |   ^~~~~~~~~~~~~
/usr/include/stdlib.h:994:30: error: expected initializer before ‘__attr_access’
  994 |      __THROW __nonnull ((2)) __attr_access ((__write_only__, 2, 3));
      |                              ^~~~~~~~~~~~~
In file included from /usr/include/c++/10/ext/string_conversions.h:41,
                 from /usr/include/c++/10/bits/basic_string.h:6545,
                 from /usr/include/c++/10/string:55,
                 from /home/ideepika/ceph5/ceph/src/rocksdb/include/rocksdb/cache.h:27,
                 from /home/ideepika/ceph5/ceph/src/rocksdb/cache/clock_cache.h:12,
                 from /home/ideepika/ceph5/ceph/src/rocksdb/cache/clock_cache.cc:10:
/usr/include/c++/10/cstdlib:154:11: error: ‘mbstowcs’ has not been declared in ‘::’
  154 |   using ::mbstowcs;
      |           ^~~~~~~~
/usr/include/c++/10/cstdlib:171:11: error: ‘wcstombs’ has not been declared in ‘::’
  171 |   using ::wcstombs;
      |           ^~~~~~~~

the source of error is merely because of #include and hence the source code from rocksdb doesn't looks suspicious.

Investigating... will update with relevant details, let me know if more details need to added

Answer 1

turns out there is recent patch added to cstdlib: https://www.cygwin.com/bugzilla/attachment.cgi?id=12133

that might have been uncaught, I did not investigate the related files right now, but the adding the minimal changes patchset if someone else bumps to this issue...

diff --git a/stdlib.h b/stdlib.h
index f255e4a..d88ef89 100644
--- a/stdlib.h
+++ b/stdlib.h
@@ -931,10 +931,11 @@ extern int wctomb (char *__s, wchar_t __wchar) __THROW;
 
 /* Convert a multibyte string to a wide char string.  */
 extern size_t mbstowcs (wchar_t *__restrict  __pwcs,
-                       const char *__restrict __s, size_t __n) __THROW
+                       const char *__restrict __s, size_t __n) __THROW;
 /* Convert a wide char string to multibyte string.  */
 extern size_t wcstombs (char *__restrict __s,
-                       const wchar_t *__restrict __pwcs, size_t __n) __THROW
+                       const wchar_t *__restrict __pwcs, size_t __n)
+     __THROW;
 
 #ifdef __USE_MISC
 /* Determine whether the string value of RESPONSE matches the affirmation
@@ -988,7 +989,7 @@ extern char *ptsname (int __fd) __THROW __wur;
    terminal associated with the master FD is open on in BUF.
    Return 0 on success, otherwise an error number.  */
 extern int ptsname_r (int __fd, char *__buf, size_t __buflen)
-     __THROW __nonnull ((2))
+     __THROW __nonnull ((2));