Fix open_memstream namespace (bug 18498)

[Joseph Myers <joseph at codesourcery dot com>]

open_memstream is new in the 2008 edition of POSIX.  However, the
older functions getopt, closelog and fmtmsg all bring in references to
it.  This patch fixes this in the usual way, making open_memstream
into a weak alias of __open_memstream and calling __open_memstream
from the relevant places.

Tested for x86_64 and x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).  32-bit builds
produce a XPASS for conform/POSIX/unistd.h/linknamespace after this
patch (because the only cause of failure left there now is 64-bit
specific); that will disappear once the 64-bit failure is resolved and
the XFAIL removed at that time.

2015-06-05  Joseph Myers  <joseph@codesourcery.com>

	[BZ #18498]
	* libio/memstream.c (open_memstream): Rename to __open_memstream
	and define as weak alias of __open_memstream.
	* include/stdio.h (__open_memstream): Declare.  Use
	libc_hidden_proto.
	(open_memstream): Don't use libc_hidden_proto.
	* misc/syslog.c (__vsyslog_chk): Call __open_memstream instead of
	open_memstream.
	* posix/getopt.c (_getopt_internal_r): Likewise.
	* conform/Makefile (test-xfail-XPG3/stdio.h/linknamespace): Remove
	variable.
	(test-xfail-XPG4/stdio.h/linknamespace): Likewise.
	(test-xfail-UNIX98/stdio.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/unistd.h/linknamespace): Likewise.

diff --git a/conform/Makefile b/conform/Makefile
index 662ea96..943a196 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -347,14 +347,12 @@ test-xfail-XOPEN2K8/ndbm.h/linknamespace = yes
 # Unsorted expected failures.
 test-xfail-XPG3/glob.h/linknamespace = yes
 test-xfail-XPG3/regex.h/linknamespace = yes
-test-xfail-XPG3/stdio.h/linknamespace = yes
 test-xfail-XPG3/unistd.h/linknamespace = yes
 test-xfail-XPG3/wordexp.h/linknamespace = yes
 test-xfail-XPG4/fmtmsg.h/linknamespace = yes
 test-xfail-XPG4/glob.h/linknamespace = yes
 test-xfail-XPG4/netdb.h/linknamespace = yes
 test-xfail-XPG4/regex.h/linknamespace = yes
-test-xfail-XPG4/stdio.h/linknamespace = yes
 test-xfail-XPG4/stdlib.h/linknamespace = yes
 test-xfail-XPG4/syslog.h/linknamespace = yes
 test-xfail-XPG4/unistd.h/linknamespace = yes
@@ -367,7 +365,6 @@ test-xfail-POSIX/unistd.h/linknamespace = yes
 test-xfail-UNIX98/fmtmsg.h/linknamespace = yes
 test-xfail-UNIX98/mqueue.h/linknamespace = yes
 test-xfail-UNIX98/netdb.h/linknamespace = yes
-test-xfail-UNIX98/stdio.h/linknamespace = yes
 test-xfail-UNIX98/stdlib.h/linknamespace = yes
 test-xfail-UNIX98/syslog.h/linknamespace = yes
 test-xfail-UNIX98/unistd.h/linknamespace = yes
@@ -376,7 +373,6 @@ test-xfail-XOPEN2K/fmtmsg.h/linknamespace = yes
 test-xfail-XOPEN2K/netdb.h/linknamespace = yes
 test-xfail-XOPEN2K/stdlib.h/linknamespace = yes
 test-xfail-XOPEN2K/syslog.h/linknamespace = yes
-test-xfail-XOPEN2K/unistd.h/linknamespace = yes
 test-xfail-POSIX2008/grp.h/linknamespace = yes
 test-xfail-POSIX2008/netdb.h/linknamespace = yes
 test-xfail-POSIX2008/semaphore.h/linknamespace = yes
diff --git a/include/stdio.h b/include/stdio.h
index 043b2b5..78bd3c4 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -160,7 +160,10 @@ extern __typeof (fgets_unlocked) __fgets_unlocked;
 libc_hidden_proto (__fgets_unlocked)
 libc_hidden_proto (fputs_unlocked)
 libc_hidden_proto (fmemopen)
-libc_hidden_proto (open_memstream)
+/* The prototype needs repeating instead of using __typeof to use
+   __THROW in C++.  */
+extern FILE *__open_memstream (char **, size_t *) __THROW __wur;
+libc_hidden_proto (__open_memstream)
 libc_hidden_proto (__libc_fatal)
 libc_hidden_proto (__vsprintf_chk)
 libc_hidden_proto (__vsnprintf_chk)
diff --git a/libio/memstream.c b/libio/memstream.c
index 81bfe6d..84742d1 100644
--- a/libio/memstream.c
+++ b/libio/memstream.c
@@ -61,7 +61,7 @@ static const struct _IO_jump_t _IO_mem_jumps =
    necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
    and the number of characters written on fflush or fclose.  */
 _IO_FILE *
-open_memstream (bufloc, sizeloc)
+__open_memstream (bufloc, sizeloc)
      char **bufloc;
      _IO_size_t *sizeloc;
 {
@@ -100,7 +100,8 @@ open_memstream (bufloc, sizeloc)
 
   return (_IO_FILE *) &new_f->fp._sf._sbf;
 }
-libc_hidden_def (open_memstream)
+libc_hidden_def (__open_memstream)
+weak_alias (__open_memstream, open_memstream)
 
 
 static int
diff --git a/misc/syslog.c b/misc/syslog.c
index 70daa9e..23a4f7b 100644
--- a/misc/syslog.c
+++ b/misc/syslog.c
@@ -164,7 +164,7 @@ __vsyslog_chk(int pri, int flag, const char *fmt, va_list ap)
 		pri |= LogFacility;
 
 	/* Build the message in a memory-buffer stream.  */
-	f = open_memstream (&buf, &bufsize);
+	f = __open_memstream (&buf, &bufsize);
 	if (f == NULL)
 	  {
 	    /* We cannot get a stream.  There is not much we can do but
diff --git a/posix/getopt.c b/posix/getopt.c
index 841392e..d30530f 100644
--- a/posix/getopt.c
+++ b/posix/getopt.c
@@ -585,7 +585,7 @@ _getopt_internal_r (int argc, char *const *argv, const char *optstring,
 	      char *buf = NULL;
 	      size_t buflen = 0;
 
-	      FILE *fp = open_memstream (&buf, &buflen);
+	      FILE *fp = __open_memstream (&buf, &buflen);
 	      if (fp != NULL)
 		{
 		  fprintf (fp,

-- 
Joseph S. Myers
joseph@codesourcery.com