Installed-header hygiene (BZ#20366): time.h types.

Many headers are expected to expose a subset of the type definitions
in time.h.  time.h has a whole bunch of messy logic for conditionally
defining some its types and structs, but, as best I can tell, this
has never worked 100%.  In particular, __need_timespec is ineffective
if _TIME_H has already been defined, which means that if you compile

  #include <time.h>
  #include <sched.h>

with e.g. -fsyntax-only -std=c89 -Wall -Wsystem-headers, you will get

In file included from test.c:2:0:
/usr/include/sched.h:74:57: warning: "struct timespec" declared inside
  parameter list will not be visible outside of this definition or declaration
 extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW;
                                                         ^~~~~~~~

And if you want to _use_ sched_rr_get_interval in a TU compiled that
way, you're hosed.

This patch replaces all of that with small bits/types/TYPE.h headers
as introduced earlier.  time.h and bits/time.h are now *much* simpler,
and a lot of other headers are slightly simpler.

	* time/time.h, bits/time.h, sysdeps/unix/sysv/linux/bits/time.h:
	Remove all logic conditional on __need macros.  Move all the
	conditionally defined types to their own headers...
	* time/bits/types/clock_t.h: Define clock_t here.
	* time/bits/types/clockid_t.h: Define clockid_t here.
	* time/bits/types/struct_itimerspec.h: Define struct itimerspec here.
	* time/bits/types/struct_timespec.h: Define struct timespec here.
	* time/bits/types/struct_timeval.h: Define struct timeval here.
	* time/bits/types/struct_tm.h: Define struct tm here.
	* time/bits/types/time_t.h: Define time_t here.
	* time/bits/types/timer_t.h: Define timer_t here.
	* time/Makefile: Install the new headers.

	* bits/resource.h, io/fcntl.h, io/sys/poll.h, io/sys/stat.h
	* io/utime.h, misc/sys/select.h, posix/sched.h, posix/sys/times.h
	* posix/sys/types.h, resolv/netdb.h, rt/aio.h, rt/mqueue.h
	* signal/signal.h, pthread/semaphore.h, sysdeps/nptl/pthread.h
	* sysdeps/unix/sysv/linux/alpha/bits/resource.h
	* sysdeps/unix/sysv/linux/alpha/sys/acct.h
	* sysdeps/unix/sysv/linux/bits/resource.h
	* sysdeps/unix/sysv/linux/bits/timex.h
	* sysdeps/unix/sysv/linux/mips/bits/resource.h
	* sysdeps/unix/sysv/linux/net/ppp_defs.h
	* sysdeps/unix/sysv/linux/sparc/bits/resource.h
	* sysdeps/unix/sysv/linux/sys/acct.h
	* sysdeps/unix/sysv/linux/sys/timerfd.h
	* sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h
	* time/sys/time.h, time/sys/timeb.h
	Use the new bits/types headers.

	* include/time.h: Remove __need logic.
	* include/bits/time.h
	* include/bits/types/clock_t.h, include/bits/types/clockid_t.h
	* include/bits/types/time_t.h, include/bits/types/timer_t.h
	* include/bits/types/struct_itimerspec.h
	* include/bits/types/struct_timespec.h
	* include/bits/types/struct_timeval.h
	* include/bits/types/struct_tm.h:
	New wrapper headers.

51 files changed, 327 insertions, 335 deletions

diff --git a/ChangeLog b/ChangeLog
index 60500b47c8..b428ba42ee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,47 @@
 2016-09-23  Zack Weinberg  <zackw@panix.com>
 
+	* time/time.h, bits/time.h, sysdeps/unix/sysv/linux/bits/time.h:
+	Remove all logic conditional on __need macros.	Move all the
+	conditionally defined types to their own headers...
+	* time/bits/types/clock_t.h: Define clock_t here.
+	* time/bits/types/clockid_t.h: Define clockid_t here.
+	* time/bits/types/struct_itimerspec.h: Define struct itimerspec here.
+	* time/bits/types/struct_timespec.h: Define struct timespec here.
+	* time/bits/types/struct_timeval.h: Define struct timeval here.
+	* time/bits/types/struct_tm.h: Define struct tm here.
+	* time/bits/types/time_t.h: Define time_t here.
+	* time/bits/types/timer_t.h: Define timer_t here.
+	* time/Makefile: Install the new headers.
+
+	* bits/resource.h, io/fcntl.h, io/sys/poll.h, io/sys/stat.h
+	* io/utime.h, misc/sys/select.h, posix/sched.h, posix/sys/times.h
+	* posix/sys/types.h, resolv/netdb.h, rt/aio.h, rt/mqueue.h
+	* signal/signal.h, pthread/semaphore.h, sysdeps/nptl/pthread.h
+	* sysdeps/unix/sysv/linux/alpha/bits/resource.h
+	* sysdeps/unix/sysv/linux/alpha/sys/acct.h
+	* sysdeps/unix/sysv/linux/bits/resource.h
+	* sysdeps/unix/sysv/linux/bits/timex.h
+	* sysdeps/unix/sysv/linux/mips/bits/resource.h
+	* sysdeps/unix/sysv/linux/net/ppp_defs.h
+	* sysdeps/unix/sysv/linux/sparc/bits/resource.h
+	* sysdeps/unix/sysv/linux/sys/acct.h
+	* sysdeps/unix/sysv/linux/sys/timerfd.h
+	* sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h
+	* time/sys/time.h, time/sys/timeb.h
+	Use the new bits/types headers.
+
+	* include/time.h: Remove __need logic.
+	* include/bits/time.h
+	* include/bits/types/clock_t.h, include/bits/types/clockid_t.h
+	* include/bits/types/time_t.h, include/bits/types/timer_t.h
+	* include/bits/types/struct_itimerspec.h
+	* include/bits/types/struct_timespec.h
+	* include/bits/types/struct_timeval.h
+	* include/bits/types/struct_tm.h:
+	New wrapper headers.
+
+2016-09-23  Zack Weinberg  <zackw@panix.com>
+
 	* sysdeps/mach/hurd/net/if_ppp.h
 	* sysdeps/unix/sysv/linux/net/if_ppp.h:
 	Only define struct ifpppstatsreq and struct ifpppcstatsreq
diff --git a/bits/resource.h b/bits/resource.h
index 7d2d66c7c9..5cd2fe56a2 100644
--- a/bits/resource.h
+++ b/bits/resource.h
@@ -129,8 +129,7 @@ enum __rusage_who
 #define RUSAGE_CHILDREN RUSAGE_CHILDREN
   };
 
-#define __need_timeval
-#include <bits/time.h>           /* For `struct timeval'.  */
+#include <bits/types/struct_timeval.h>
 
 /* Structure which says how much of each resource has been used.  */
 struct rusage
diff --git a/bits/time.h b/bits/time.h
index 19c7ab0997..84e0e94a17 100644
--- a/bits/time.h
+++ b/bits/time.h
@@ -20,9 +20,10 @@
  * Never include this file directly; use <time.h> instead.
  */
 
-#ifndef __need_timeval
-# ifndef _BITS_TIME_H
-#  define _BITS_TIME_H	1
+#ifndef _BITS_TIME_H
+#define _BITS_TIME_H	1
+
+#include <bits/types.h>
 
 /* ISO/IEC 9899:1999 7.23.1: Components of time
    The macro `CLOCKS_PER_SEC' is an expression with type `clock_t' that is
@@ -30,51 +31,34 @@
 /* CAE XSH, Issue 4, Version 2: <time.h>
    The value of CLOCKS_PER_SEC is required to be 1 million on all
    XSI-conformant systems. */
-#  define CLOCKS_PER_SEC  ((clock_t) 1000000)
+#define CLOCKS_PER_SEC  ((__clock_t) 1000000)
 
-#  if !defined __STRICT_ANSI__ && !defined __USE_XOPEN2K
+#if (!defined __STRICT_ANSI__ || defined __USE_POSIX) \
+   && !defined __USE_XOPEN2K
 /* Even though CLOCKS_PER_SEC has such a strange value CLK_TCK
    presents the real value for clock ticks per second for the system.  */
-#   include <bits/types.h>
 extern long int __sysconf (int);
-#   define CLK_TCK ((__clock_t) __sysconf (2))	/* 2 is _SC_CLK_TCK */
-#  endif
+# define CLK_TCK ((__clock_t) __sysconf (2))	/* 2 is _SC_CLK_TCK */
+#endif
 
-#  ifdef __USE_POSIX199309
+#ifdef __USE_POSIX199309
 /* Identifier for system-wide realtime clock.  */
-#   define CLOCK_REALTIME		0
+# define CLOCK_REALTIME			0
 /* Monotonic system-wide clock.  */
-#   define CLOCK_MONOTONIC		1
+# define CLOCK_MONOTONIC		1
 /* High-resolution timer from the CPU.  */
-#   define CLOCK_PROCESS_CPUTIME_ID	2
+# define CLOCK_PROCESS_CPUTIME_ID	2
 /* Thread-specific CPU-time clock.  */
-#   define CLOCK_THREAD_CPUTIME_ID	3
+# define CLOCK_THREAD_CPUTIME_ID	3
 /* Monotonic system-wide clock, not adjusted for frequency scaling.  */
-#   define CLOCK_MONOTONIC_RAW		4
+# define CLOCK_MONOTONIC_RAW		4
 /* Identifier for system-wide realtime clock, updated only on ticks.  */
-#   define CLOCK_REALTIME_COARSE	5
+# define CLOCK_REALTIME_COARSE		5
 /* Monotonic system-wide clock, updated only on ticks.  */
-#   define CLOCK_MONOTONIC_COARSE	6
+# define CLOCK_MONOTONIC_COARSE		6
 
 /* Flag to indicate time is absolute.  */
-#   define TIMER_ABSTIME		1
-#  endif
-
-# endif	/* bits/time.h */
+# define TIMER_ABSTIME			1
 #endif
 
-#ifdef __need_timeval
-# undef __need_timeval
-# ifndef _STRUCT_TIMEVAL
-#  define _STRUCT_TIMEVAL	1
-#  include <bits/types.h>
-
-/* A time value that is accurate to the nearest
-   microsecond but also has a range of years.  */
-struct timeval
-  {
-    __time_t tv_sec;		/* Seconds.  */
-    __suseconds_t tv_usec;	/* Microseconds.  */
-  };
-# endif	/* struct timeval */
-#endif	/* need timeval */
+#endif	/* bits/time.h */
diff --git a/include/bits/types/clock_t.h b/include/bits/types/clock_t.h
new file mode 100644
index 0000000000..a08940dbef
--- /dev/null
+++ b/include/bits/types/clock_t.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/clock_t.h"
diff --git a/include/bits/types/clockid_t.h b/include/bits/types/clockid_t.h
new file mode 100644
index 0000000000..fb0a514446
--- /dev/null
+++ b/include/bits/types/clockid_t.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/clockid_t.h"
diff --git a/include/bits/types/struct_itimerspec.h b/include/bits/types/struct_itimerspec.h
new file mode 100644
index 0000000000..7d325d6f3c
--- /dev/null
+++ b/include/bits/types/struct_itimerspec.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/struct_itimerspec.h"
diff --git a/include/bits/types/struct_timespec.h b/include/bits/types/struct_timespec.h
new file mode 100644
index 0000000000..b8ec6a3862
--- /dev/null
+++ b/include/bits/types/struct_timespec.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/struct_timespec.h"
diff --git a/include/bits/types/struct_timeval.h b/include/bits/types/struct_timeval.h
new file mode 100644
index 0000000000..5d2cb78259
--- /dev/null
+++ b/include/bits/types/struct_timeval.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/struct_timeval.h"
diff --git a/include/bits/types/struct_tm.h b/include/bits/types/struct_tm.h
new file mode 100644
index 0000000000..b70ac52f68
--- /dev/null
+++ b/include/bits/types/struct_tm.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/struct_tm.h"
diff --git a/include/bits/types/time_t.h b/include/bits/types/time_t.h
new file mode 100644
index 0000000000..16e75e19be
--- /dev/null
+++ b/include/bits/types/time_t.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/time_t.h"
diff --git a/include/bits/types/timer_t.h b/include/bits/types/timer_t.h
new file mode 100644
index 0000000000..e6b279bfcc
--- /dev/null
+++ b/include/bits/types/timer_t.h
@@ -0,0 +1 @@
+#include "../../time/bits/types/timer_t.h"
diff --git a/include/time.h b/include/time.h
index 8dd10dcdd8..684ceb812f 100644
--- a/include/time.h
+++ b/include/time.h
@@ -1,8 +1,7 @@
 #ifndef _TIME_H
-#if defined __need_time_t  || defined __need_clock_t || defined __need_timespec || defined _ISOMAC
-# include <time/time.h>
-#else
-# include <time/time.h>
+#include <time/time.h>
+
+#ifndef _ISOMAC
 # include <xlocale.h>
 
 __BEGIN_DECLS
diff --git a/io/fcntl.h b/io/fcntl.h
index cb706b4f0f..12099a2181 100644
--- a/io/fcntl.h
+++ b/io/fcntl.h
@@ -72,8 +72,7 @@ typedef __pid_t pid_t;