Installed-header hygiene (BZ#20366): Simple self-contained fixes.

Some headers did not include all of their prerequisite headers.

	* rpcsvc/nislib.h: Include rpcsvc/nis.h.
	* sysdeps/unix/sysv/linux/netrose/rose.h:
	Include sys/socket.h and netax25/ax25.h.

<endian.h> only defines BYTE_ORDER, BIG_ENDIAN, LITTLE_ENDIAN,
etc. under __USE_MISC; glibc's headers should use __BYTE_ORDER,
__BIG_ENDIAN, __LITTLE_ENDIAN, etc. instead.

	* inet/netinet/icmp6.h, inet/netinet/ip6.h
	* resolv/arpa/nameser_compat.h:
	Use __BYTE_ORDER etc. instead of BYTE_ORDER etc.

sys/types.h only conditionally defines caddr_t and clockid_t.

	* sysdeps/unix/sysv/linux/sys/quota.h:
	Use __caddr_t instead of caddr_t.
	* sysdeps/unix/sysv/linux/sys/timerfd.h:
	Use __clockid_t instead of clockid_t.

Remove a #warning that was the sole actual problem with using sys/ipc.h
without _GNU_SOURCE/_XOPEN_SOURCE.

	* sysvipc/sys/ipc.h: Remove unnecessary #warning.

_LIBC, __USE_XOPEN2K8, and __STDC_VERSION__ are not always defined.

It seems to me that _LIBC should not appear in installed headers, but
avoiding that for argp specifically would require more surgery than
feels appropriate for this patch set.  It's possible that
"#ifdef _LIBC" would be sufficient, but I wanted to be conservative.

All three versions of bits/socket.h want to know whether __flexarr
will produce a real flexible array member -- specifically, one that
doesn't alter sizeof(the structure containing it).  They were testing
for this with a complicated #if condition that did not agree with
sys/cdefs.h and that tripped -Wundef warnings under -std=c90.
I added a new macro to sys/cdefs.h, __glibc_c99_flexarr_available,
which reveals exactly what these headers want to know.  I also took
the opportunity to flatten the rather messy conditional nest defining
__flexarr.

	* argp/argp.h: Check whether _LIBC is defined before expanding it.
	* posix/glob.h: Check whether __USE_XOPEN2K8 is defined instead
	of expanding it.

	* misc/sys/cdefs.h: Tidy up conditional nest defining __flexarr.
	Define __glibc_c99_flexarr_available to 1 when the compiler
	supports C99-compatible flexible array members, 0 otherwise.
	* sysdeps/unix/sysv/linux/bits/socket.h
	* sysdeps/mach/hurd/bits/socket.h
	* bits/socket.h: Use __glibc_c99_flexarr_available in
	definitions of struct cmsghdr and CMSG_DATA.

15 files changed, 74 insertions, 40 deletions

diff --git a/ChangeLog b/ChangeLog
index 379b6d4..f4ea6f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,32 @@
+2016-09-23  Zack Weinberg  <zackw@panix.com>
+
+	* rpcsvc/nislib.h: Include rpcsvc/nis.h.
+	* sysdeps/unix/sysv/linux/netrose/rose.h:
+	Include sys/socket.h and netax25/ax25.h.
+
+	* inet/netinet/icmp6.h, inet/netinet/ip6.h
+	* resolv/arpa/nameser_compat.h:
+	Use __BYTE_ORDER etc. instead of BYTE_ORDER etc.
+
+	* sysdeps/unix/sysv/linux/sys/quota.h:
+	Use __caddr_t instead of caddr_t.
+	* sysdeps/unix/sysv/linux/sys/timerfd.h:
+	Use __clockid_t instead of clockid_t.
+
+	* sysvipc/sys/ipc.h: Remove unnecessary #warning.
+
+	* argp/argp.h: Check whether _LIBC is defined before expanding it.
+	* posix/glob.h: Check whether __USE_XOPEN2K8 is defined instead of
+	expanding it.
+
+	* misc/sys/cdefs.h: Tidy up conditional nest defining __flexarr.
+	Define __glibc_c99_flexarr_available to 1 when the compiler
+	supports C99-compatible flexible array members, 0 otherwise.
+	* sysdeps/unix/sysv/linux/bits/socket.h
+	* sysdeps/mach/hurd/bits/socket.h
+	* bits/socket.h: Use __glibc_c99_flexarr_available in
+	definitions of struct cmsghdr and CMSG_DATA.
+
 2016-09-23  Florian Weimer  <fweimer@redhat.com>
 
 	* manual/nss.texi (NSS Modules Interface): Adjust function return
diff --git a/argp/argp.h b/argp/argp.h
index 7cb5a69..5066776 100644
--- a/argp/argp.h
+++ b/argp/argp.h
@@ -511,7 +511,7 @@ extern void *__argp_input (const struct argp *__restrict __argp,
 
 #ifdef __USE_EXTERN_INLINES
 
-# if !_LIBC
+# if !(defined _LIBC && _LIBC)
 #  define __argp_usage argp_usage
 #  define __argp_state_help argp_state_help
 #  define __option_is_short _option_is_short
@@ -546,7 +546,7 @@ __NTH (__option_is_end (const struct argp_option *__opt))
   return !__opt->key && !__opt->name && !__opt->doc && !__opt->group;
 }
 
-# if !_LIBC
+# if !(defined _LIBC && _LIBC)
 #  undef __argp_usage
 #  undef __argp_state_help
 #  undef __option_is_short
diff --git a/bits/socket.h b/bits/socket.h
index a22fd56..18adca4 100644
--- a/bits/socket.h
+++ b/bits/socket.h
@@ -216,13 +216,13 @@ struct cmsghdr
 				   of cmsghdr structure.  */
     int cmsg_level;		/* Originating protocol.  */
     int cmsg_type;		/* Protocol specific type.  */
-#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
+#if __glibc_c99_flexarr_available
     __extension__ unsigned char __cmsg_data __flexarr; /* Ancillary data.  */
 #endif
   };
 
 /* Ancillary data object manipulation macros.  */
-#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
+#if __glibc_c99_flexarr_available
 # define CMSG_DATA(cmsg) ((cmsg)->__cmsg_data)
 #else
 # define CMSG_DATA(cmsg) ((unsigned char *) ((struct cmsghdr *) (cmsg) + 1))
diff --git a/inet/netinet/icmp6.h b/inet/netinet/icmp6.h
index b7a9637..89e3f8d 100644
--- a/inet/netinet/icmp6.h
+++ b/inet/netinet/icmp6.h
@@ -160,11 +160,11 @@ struct nd_neighbor_advert     /* neighbor advertisement */
 #define nd_na_code               nd_na_hdr.icmp6_code
 #define nd_na_cksum              nd_na_hdr.icmp6_cksum
 #define nd_na_flags_reserved     nd_na_hdr.icmp6_data32[0]
-#if     BYTE_ORDER == BIG_ENDIAN
+#if     __BYTE_ORDER == __BIG_ENDIAN
 #define ND_NA_FLAG_ROUTER        0x80000000
 #define ND_NA_FLAG_SOLICITED     0x40000000
 #define ND_NA_FLAG_OVERRIDE      0x20000000
-#else   /* BYTE_ORDER == LITTLE_ENDIAN */
+#else   /* __BYTE_ORDER == __LITTLE_ENDIAN */
 #define ND_NA_FLAG_ROUTER        0x00000080
 #define ND_NA_FLAG_SOLICITED     0x00000040
 #define ND_NA_FLAG_OVERRIDE      0x00000020
@@ -298,10 +298,10 @@ struct rr_pco_use      /* use prefix part */
 #define ICMP6_RR_PCOUSE_RAFLAGS_ONLINK  0x20
 #define ICMP6_RR_PCOUSE_RAFLAGS_AUTO    0x10
 
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
 # define ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME 0x80000000
 # define ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME 0x40000000
-#elif BYTE_ORDER == LITTLE_ENDIAN
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
 # define ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME 0x80
 # define ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME 0x40
 #endif
@@ -315,10 +315,10 @@ struct rr_result       /* router renumbering result message */
     struct in6_addr     rrr_prefix;
   };
 
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
 # define ICMP6_RR_RESULT_FLAGS_OOB       0x0002
 # define ICMP6_RR_RESULT_FLAGS_FORBIDDEN 0x0001
-#elif BYTE_ORDER == LITTLE_ENDIAN
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
 # define ICMP6_RR_RESULT_FLAGS_OOB       0x0200
 # define ICMP6_RR_RESULT_FLAGS_FORBIDDEN 0x0100
 #endif
diff --git a/inet/netinet/ip6.h b/inet/netinet/ip6.h
index 929d4b5..bd02c94 100644
--- a/inet/netinet/ip6.h
+++ b/inet/netinet/ip6.h
@@ -101,11 +101,11 @@ struct ip6_frag
     uint32_t  ip6f_ident;	/* identification */
   };
 
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
 # define IP6F_OFF_MASK       0xfff8  /* mask out offset from _offlg */
 # define IP6F_RESERVED_MASK  0x0006  /* reserved bits in ip6f_offlg */
 # define IP6F_MORE_FRAG      0x0001  /* more-fragments flag */
-#else   /* BYTE_ORDER == LITTLE_ENDIAN */
+#else   /* __BYTE_ORDER == __LITTLE_ENDIAN */
 # define IP6F_OFF_MASK       0xf8ff  /* mask out offset from _offlg */
 # define IP6F_RESERVED_MASK  0x0600  /* reserved bits in ip6f_offlg */
 # define IP6F_MORE_FRAG      0x0100  /* more-fragments flag */
@@ -175,11 +175,11 @@ struct ip6_opt_router
   };
 
 /* Router alert values (in network byte order) */
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
 # define IP6_ALERT_MLD	0x0000
 # define IP6_ALERT_RSVP	0x0001
 # define IP6_ALERT_AN	0x0002
-#else /* BYTE_ORDER == LITTLE_ENDING */
+#else /* __BYTE_ORDER == __LITTLE_ENDIAN */
 # define IP6_ALERT_MLD	0x0000
 # define IP6_ALERT_RSVP	0x0100
 # define IP6_ALERT_AN	0x0200
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 6e9b840..935a94b 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -153,21 +153,27 @@
 # define __errordecl(name, msg) extern void name (void)
 #endif
 
-/* Support for flexible arrays.  */
-#if __GNUC_PREREQ (2,97)
-/* GCC 2.97 supports C99 flexible array members.  */
+/* Support for flexible arrays.
+   Headers that should use flexible arrays only if they're "real"
+   (e.g. only if they won't affect sizeof()) should test
+   #if __glibc_c99_flexarr_available.  */
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+# define __flexarr	[]
+# define __glibc_c99_flexarr_available 1
+#elif __GNUC_PREREQ (2,97)
+/* GCC 2.97 supports C99 flexible array members as an extension,
+   even when in C89 mode or compiling C++ (any version).  */
 # define __flexarr	[]
+# define __glibc_c99_flexarr_available 1
+#elif defined __GNUC__
+/* Pre-2.97 GCC did not support C99 flexible arrays but did have
+   an equivalent extension with slightly different notation.  */
+# define __flexarr	[0]
+# define __glibc_c99_flexarr_available 1
 #else
-# ifdef __GNUC__
-#  define __flexarr	[0]
-# else
-#  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
-#   define __flexarr	[]
-#  else
 /* Some other non-C99 compiler.  Approximate with [1].  */
-#   define __flexarr	[1]
-#  endif
-# endif
+# define __flexarr	[1]
+# define __glibc_c99_flexarr_available 0
 #endif
 
 
diff --git a/nis/rpcsvc/nislib.h b/nis/rpcsvc/nislib.h
index 21a8e48..1a7c3c5 100644
--- a/nis/rpcsvc/nislib.h
+++ b/nis/rpcsvc/nislib.h
@@ -19,7 +19,7 @@
 #ifndef	__RPCSVC_NISLIB_H__
 #define	__RPCSVC_NISLIB_H__
 
-#include <features.h>
+#include <rpcsvc/nis.h>
 
 __BEGIN_DECLS
 
diff --git a/posix/glob.h b/posix/glob.h
index e4548f6..ae70fa7 100644
--- a/posix/glob.h
+++ b/posix/glob.h
@@ -25,7 +25,7 @@ __BEGIN_DECLS
 /* We need `size_t' for the following definitions.  */
 #ifndef __size_t
 typedef __SIZE_TYPE__ __size_t;
-# if defined __USE_XOPEN || __USE_XOPEN2K8
+# if defined __USE_XOPEN || defined __USE_XOPEN2K8
 typedef __SIZE_TYPE__ size_t;
 # endif
 #else
diff --git a/resolv/arpa/nameser_compat.h b/resolv/arpa/nameser_compat.h
index ccc2d52..6a2f029 100644
--- a/resolv/arpa/nameser_compat.h
+++ b/resolv/arpa/nameser_compat.h
@@ -40,7 +40,7 @@
 
 typedef struct {
 	unsigned	id :16;		/*%< query identification number */
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
 			/* fields in third byte */
 	unsigned	qr: 1;		/*%< response flag */
 	unsigned	opcode: 4;	/*%< purpose of message */
@@ -54,7 +54,7 @@ typedef struct {
 	unsigned	cd: 1;		/*%< checking disabled by resolver */
 	unsigned	rcode :4;	/*%< response code */
 #endif
-#if BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
+#if __BYTE_ORDER == __LITTLE_ENDIAN || __BYTE_ORDER == __PDP_ENDIAN
 			/* fields in third byte */
 	unsigned	rd :1;		/*%< recursion desired */
 	unsigned	tc :1;		/*%< truncated message */
diff --git a/sysdeps/mach/hurd/bits/socket.h b/sysdeps/mach/hurd/bits/socket.h
index 257e438..5a8cd89 100644
--- a/sysdeps/mach/hurd/bits/socket.h
+++ b/sysdeps/mach/hurd/bits/socket.h
@@ -220,13 +220,13 @@ struct cmsghdr
 				   of cmsghdr structure.  */
     int cmsg_level;		/* Originating protocol.  */
     int cmsg_type;		/* Protocol specific type.  */
-#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
+#if __glibc_c99_flexarr_available
     __extension__ unsigned char __cmsg_data __flexarr; /* Ancillary data.  */
 #endif
   };
 
 /* Ancillary data object manipulation macros.  */
-#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
+#if __glibc_c99_flexarr_available
 # define CMSG_DATA(cmsg) ((cmsg)->__cmsg_data)
 #else
 # define CMSG_DATA(cmsg) ((unsigned char *) ((struct cmsghdr *) (cmsg) + 1))
diff --git a/sysdeps/unix/sysv/linux/bits/socket.h b/sysdeps/unix/sysv/linux/bits/socket.h
index 2266047..514c373 100644
--- a/sysdeps/unix/sysv/linux/bits/socket.h
+++ b/sysdeps/unix/sysv/linux/bits/socket.h
@@ -273,13 +273,13 @@ struct cmsghdr
 				   with this.  */
     int cmsg_level;		/* Originating protocol.  */
     int cmsg_type;		/* Protocol specific type.  */
-#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
+#if __glibc_c99_flexarr_available
     __extension__ unsigned char __cmsg_data __flexarr; /* Ancillary data.  */
 #endif
   };
 
 /* Ancillary data object manipulation macros.  */
-#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
+#if __glibc_c99_flexarr_available
 # define CMSG_DATA(cmsg) ((cmsg)->__cmsg_data)
 #else
 # define CMSG_DATA(cmsg) ((unsigned char *) ((struct cmsghdr *) (cmsg) + 1))
diff --git a/sysdeps/unix/sysv/linux/netrose/rose.h b/sysdeps/unix/sysv/linux/netrose/rose.h
index 3cb7f84..762d3f5 100644
--- a/sysdeps/unix/sysv/linux/netrose/rose.h
+++ b/sysdeps/unix/sysv/linux/netrose/rose.h
@@ -21,6 +21,9 @@
 #ifndef _NETROSE_ROSE_H
 #define _NETROSE_ROSE_H 1
 
+#include <sys/socket.h>
+#include <netax25/ax25.h>
+
 /* Socket level values.  */
 #define SOL_ROSE        260
 
diff --git a/sysdeps/unix/sysv/linux/sys/quota.h b/sysdeps/unix/sysv/linux/sys/quota.h
index 1deafda..f34e741 100644
--- a/sysdeps/unix/sysv/linux/sys/quota.h
+++ b/sysdeps/unix/sysv/linux/sys/quota.h
@@ -128,7 +128,7 @@ struct dqinfo
 __BEGIN_DECLS
 
 extern int quotactl (int __cmd, const char *__special, int __id,
-		     caddr_t __addr) __THROW;
+		     __caddr_t __addr) __THROW;
 
 __END_DECLS
 
diff --git a/sysdeps/unix/sysv/linux/sys/timerfd.h b/sysdeps/unix/sysv/linux/sys/timerfd.h
index 3286997..d037213 100644
--- a/sysdeps/unix/sysv/linux/sys/timerfd.h
+++ b/sysdeps/unix/sysv/linux/sys/timerfd.h
@@ -35,7 +35,7 @@ enum
 __BEGIN_DECLS
 
 /* Return file descriptor for new interval timer source.  */
-extern int timerfd_create (clockid_t __clock_id, int __flags) __THROW;
+extern int timerfd_create (__clockid_t __clock_id, int __flags) __THROW;
 
 /* Set next expiration time of interval timer source UFD to UTMR.  If
    FLAGS has the TFD_TIMER_ABSTIME flag set the timeout value is
diff --git a/sysvipc/sys/ipc.h b/sysvipc/sys/ipc.h
index 70bd7a6..0392662 100644
--- a/sysvipc/sys/ipc.h
+++ b/sysvipc/sys/ipc.h
@@ -20,10 +20,6 @@
 
 #include <features.h>
 
-#if !defined __USE_MISC && !defined __USE_XOPEN && __GNUC__ >= 2
-# warning "Files using this header must be compiled with _GNU_SOURCE or _XOPEN_SOURCE"
-#endif
-
 /* Get system dependent definition of `struct ipc_perm' and more.  */
 #include <bits/ipctypes.h>
 #include <bits/ipc.h>