Fix -Os gnu_dev_* linknamespace, localplt issues (bug 15105, bug 19463).

Building with -Os produces linknamespace and localplt failures for,
among other functions, gnu_dev_major, gnu_dev_minor and
gnu_dev_makedev.

The issue is that those functions are not inlined when building with
-Os.  While one could force them to be inlined in that case, it seems
more natural to fix this issue similarly to other namespace issues.
Thus, this patch makes gnu_dev_* into weak aliases for hidden symbols
__gnu_dev_*; __gnu_dev_* are then defined as inlines in the internal
include/sys/sysmacros.h, and uses of gnu_dev_* (often via the macros
major, minor and makedev) for which there are namespace issues are
changed to use __gnu_dev_*; where there are no namespace issues, use
of libc_hidden_proto serves to avoid unnecessary local PLT entry use.

Tested for x86_64, (a) without -Os, to verify the testsuite continues
to pass without problems and that the functions called under their new
names continue to be inlined as expected in that case; (b) with -Os,
to verify that the linknamespace and localplt failures in question go
away (but because of other such failures present, neither of the
relevant bugs can yet be closed).

	[BZ #15105]
	[BZ #19463]
	* include/sys/sysmacros.h [!_ISOMAC]
	(__SYSMACROS_NEED_IMPLEMENTATION): Define macro.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC]
	(_SYS_SYSMACROS_H_WRAPPER): Likewise.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (gnu_dev_major): Use
	libc_hidden_proto.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (gnu_dev_minor): Likewise.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (gnu_dev_makedev):
	Likewise.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__SYSMACROS_DECL_TEMPL):
	Undefine and redefine to add use __gnu_dev_ prefix.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__SYSMACROS_IMPL_TEMPL):
	Likewise.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__gnu_dev_major): Declare
	and define as hidden inline function.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__gnu_dev_minor):
	Likewise.
	[!_SYS_SYSMACROS_H_WRAPPER && !_ISOMAC] (__gnu_dev_makedev):
	Likewise.
	* misc/makedev.c (OUT_OF_LINE_IMPL_TEMPL): Use __gnu_dev_ prefix.
	(gnu_dev_major): Use weak_alias and libc_hidden_weak.
	(gnu_dev_minor): Likewise.
	(gnu_dev_makedev): Likewise.
	* csu/check_fds.c (check_one_fd): Use __gnu_dev_makedev instead of
	makedev.
	* posix/wordexp.c (exec_comm_child): Likewise.
	* sysdeps/mach/hurd/xmknodat.c (__xmknodat): Use __gnu_dev_minor
	instead of minor and __gnu_dev_major instead of major.
	* sysdeps/unix/sysv/linux/device-nrs.h (DEV_TTY_P): Use
	__gnu_dev_major instead of major.
	* sysdeps/unix/sysv/linux/pathconf.c (distinguish_extX): Use
	__gnu_dev_major instead of gnu_dev_major and __gnu_dev_minor
	instead of gnu_dev_minor.
	* sysdeps/unix/sysv/linux/ptsname.c (MASTER_P): Likewise.
	(SLAVE_P): Likewise.
	(__ptsname_internal): Use __gnu_dev_minor instead of minor.
	* sysdeps/unix/sysv/linux/ttyname.h (is_pty): Use __gnu_dev_major
	instead of major.

(cherry picked from commit 8b4a118222)

csu/check_fds.c

@@ -50,12 +50,12 @@ check_one_fd (int fd, int mode)
       if ((mode & O_ACCMODE) == O_WRONLY)
 	{
 	  name = _PATH_DEV "full";
-	  dev = makedev (DEV_FULL_MAJOR, DEV_FULL_MINOR);
+	  dev = __gnu_dev_makedev (DEV_FULL_MAJOR, DEV_FULL_MINOR);
 	}
       else
 	{
 	  name = _PATH_DEVNULL;
-	  dev = makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR);
+	  dev = __gnu_dev_makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR);
 	}
 
       /* Something is wrong with this descriptor, it's probably not

include/sys/sysmacros.h

@@ -1 +1,52 @@
+/* Definitions of macros to access 'dev_t' values.  Internal header.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _ISOMAC
+# define __SYSMACROS_NEED_IMPLEMENTATION
+#endif
+
 #include <misc/sys/sysmacros.h>
+
+#if !defined _SYS_SYSMACROS_H_WRAPPER && !defined _ISOMAC
+# define _SYS_SYSMACROS_H_WRAPPER 1
+
+libc_hidden_proto (gnu_dev_major)
+libc_hidden_proto (gnu_dev_minor)
+libc_hidden_proto (gnu_dev_makedev)
+
+# undef __SYSMACROS_DECL_TEMPL
+# define __SYSMACROS_DECL_TEMPL(rtype, name, proto)	\
+  extern rtype __gnu_dev_##name proto			\
+  __THROW __attribute_const__ attribute_hidden;
+
+# undef __SYSMACROS_IMPL_TEMPL
+# define __SYSMACROS_IMPL_TEMPL(rtype, name, proto)		\
+  __extension__ __extern_inline __attribute_const__ rtype	\
+  __NTH (__gnu_dev_##name proto)
+
+__SYSMACROS_DECLARE_MAJOR (__SYSMACROS_DECL_TEMPL)
+__SYSMACROS_DECLARE_MINOR (__SYSMACROS_DECL_TEMPL)
+__SYSMACROS_DECLARE_MAKEDEV (__SYSMACROS_DECL_TEMPL)
+
+# ifdef __USE_EXTERN_INLINES
+__SYSMACROS_DEFINE_MAJOR (__SYSMACROS_IMPL_TEMPL)
+__SYSMACROS_DEFINE_MINOR (__SYSMACROS_IMPL_TEMPL)
+__SYSMACROS_DEFINE_MAKEDEV (__SYSMACROS_IMPL_TEMPL)
+# endif
+
+#endif

misc/makedev.c

@@ -23,8 +23,14 @@
 #include <sys/sysmacros.h>
 
 #define OUT_OF_LINE_IMPL_TEMPL(rtype, name, proto) \
-  rtype gnu_dev_##name proto
+  rtype __gnu_dev_##name proto
 
 __SYSMACROS_DEFINE_MAJOR(OUT_OF_LINE_IMPL_TEMPL)
+weak_alias (__gnu_dev_major, gnu_dev_major)
+libc_hidden_weak (gnu_dev_major)
 __SYSMACROS_DEFINE_MINOR(OUT_OF_LINE_IMPL_TEMPL)
+weak_alias (__gnu_dev_minor, gnu_dev_minor)
+libc_hidden_weak (gnu_dev_minor)
 __SYSMACROS_DEFINE_MAKEDEV(OUT_OF_LINE_IMPL_TEMPL)
+weak_alias (__gnu_dev_makedev, gnu_dev_makedev)
+libc_hidden_weak (gnu_dev_makedev)

posix/wordexp.c

@@ -837,7 +837,7 @@ exec_comm_child (char *comm, int *fildes, int showerr, int noexec)
       if (__builtin_expect (__fxstat64 (_STAT_VER, STDERR_FILENO, &st), 0) != 0
 	  || __builtin_expect (S_ISCHR (st.st_mode), 1) == 0
 #if defined DEV_NULL_MAJOR && defined DEV_NULL_MINOR
-	  || st.st_rdev != makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR)
+	  || st.st_rdev != __gnu_dev_makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR)
 #endif
 	  )
 	/* It's not the /dev/null device.  Stop right here.  The

sysdeps/mach/hurd/xmknodat.c

@@ -81,9 +81,9 @@ __xmknodat (int vers, int fd, const char *path, mode_t mode, dev_t *dev)
 
       bp = buf + sizeof (buf);
       *--bp = '\0';
-      bp = _itoa (minor (*dev), bp, 10, 0);
+      bp = _itoa (__gnu_dev_minor (*dev), bp, 10, 0);
       *--bp = '\0';
-      bp = _itoa (major (*dev), bp, 10, 0);
+      bp = _itoa (__gnu_dev_major (*dev), bp, 10, 0);
       memcpy (bp - len, translator, len);
       translator = bp - len;
       len = buf + sizeof (buf) - translator;

sysdeps/unix/sysv/linux/device-nrs.h

@@ -39,7 +39,7 @@
 
 /* Test whether given device is a tty.  */
 #define DEV_TTY_P(statp) \
-  ({ int __dev_major = major ((statp)->st_rdev);			      \
+  ({ int __dev_major = __gnu_dev_major ((statp)->st_rdev);		      \
      __dev_major >= DEV_TTY_LOW_MAJOR && __dev_major <= DEV_TTY_HIGH_MAJOR; })
 
 #endif	/* device-nrs.h */

sysdeps/unix/sysv/linux/pathconf.c

@@ -73,7 +73,7 @@ distinguish_extX (const struct statfs *fsbuf, const char *file, int fd)
     return EXT2_LINK_MAX;
 
   __snprintf (buf, sizeof (buf), "/sys/dev/block/%u:%u",
-	      gnu_dev_major (st.st_dev), gnu_dev_minor (st.st_dev));
+	      __gnu_dev_major (st.st_dev), __gnu_dev_minor (st.st_dev));
 
   ssize_t n = __readlink (buf, path, sizeof (path));
   if (n != -1 && n < sizeof (path))

sysdeps/unix/sysv/linux/ptsname.c

@@ -29,16 +29,18 @@
 #include <_itoa.h>
 
 /* Check if DEV corresponds to a master pseudo terminal device.  */
-#define MASTER_P(Dev)                                                         \
-  (major ((Dev)) == 2                                                         \
-   || (major ((Dev)) == 4 && minor ((Dev)) >= 128 && minor ((Dev)) < 192)     \
-   || (major ((Dev)) >= 128 && major ((Dev)) < 136))
+#define MASTER_P(Dev)							\
+  (__gnu_dev_major ((Dev)) == 2						\
+   || (__gnu_dev_major ((Dev)) == 4					\
+       && __gnu_dev_minor ((Dev)) >= 128 && __gnu_dev_minor ((Dev)) < 192) \
+   || (__gnu_dev_major ((Dev)) >= 128 && __gnu_dev_major ((Dev)) < 136))
 
 /* Check if DEV corresponds to a slave pseudo terminal device.  */
-#define SLAVE_P(Dev)                                                          \
-  (major ((Dev)) == 3                                                         \
-   || (major ((Dev)) == 4 && minor ((Dev)) >= 192 && minor ((Dev)) < 256)     \
-   || (major ((Dev)) >= 136 && major ((Dev)) < 144))
+#define SLAVE_P(Dev)							\
+  (__gnu_dev_major ((Dev)) == 3						\
+   || (__gnu_dev_major ((Dev)) == 4					\
+       && __gnu_dev_minor ((Dev)) >= 192 && __gnu_dev_minor ((Dev)) < 256) \
+   || (__gnu_dev_major ((Dev)) >= 136 && __gnu_dev_major ((Dev)) < 144))
 
 /* Note that major number 4 corresponds to the old BSD style pseudo
    terminal devices.  As of Linux 2.1.115 these are no longer
@@ -122,7 +124,7 @@ __ptsname_internal (int fd, char *buf, size_t buflen, struct stat64 *stp)
 	  return ENOTTY;
 	}
 
-      ptyno = minor (stp->st_rdev);
+      ptyno = __gnu_dev_minor (stp->st_rdev);
 
       if (ptyno / 16 >= strlen (__libc_ptyname1))
 	{

sysdeps/unix/sysv/linux/ttyname.h

@@ -28,7 +28,7 @@ static inline bool
 is_pty (struct stat64 *sb)
 {
 #ifdef _STATBUF_ST_RDEV
-  int m = major (sb->st_rdev);
+  int m = __gnu_dev_major (sb->st_rdev);
   return (136 <= m && m <= 143);
 #else
   return false;