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.

3 files changed, 27 insertions, 45 deletions

diff --git a/sysdeps/unix/sysv/linux/bits/resource.h b/sysdeps/unix/sysv/linux/bits/resource.h
index 8af0e0e95e..e2a62bc6e5 100644
--- a/sysdeps/unix/sysv/linux/bits/resource.h
+++ b/sysdeps/unix/sysv/linux/bits/resource.h
@@ -175,8 +175,7 @@ enum __rusage_who
 #endif
 };
 
-#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.  */
 
diff --git a/sysdeps/unix/sysv/linux/bits/time.h b/sysdeps/unix/sysv/linux/bits/time.h
index 87eb51f2ed..1fade54b62 100644
--- a/sysdeps/unix/sysv/linux/bits/time.h
+++ b/sysdeps/unix/sysv/linux/bits/time.h
@@ -20,24 +20,10 @@
  * Never include this file directly; use <time.h> instead.
  */
 
-#if defined __need_timeval || defined __USE_GNU
-# ifndef _STRUCT_TIMEVAL
-#  define _STRUCT_TIMEVAL	1
-#  include <bits/types.h>
+#ifndef _BITS_TIME_H
+#define _BITS_TIME_H	1
 
-/* 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
-
-#ifndef __need_timeval
-# 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
@@ -45,47 +31,46 @@ struct timeval
 /* 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_POSIX) \
+#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
 /* Monotonic system-wide clock that includes time spent in suspension.  */
-#   define CLOCK_BOOTTIME		7
+# define CLOCK_BOOTTIME			7
 /* Like CLOCK_REALTIME but also wakes suspended system.  */
-#   define CLOCK_REALTIME_ALARM		8
+# define CLOCK_REALTIME_ALARM		8
 /* Like CLOCK_BOOTTIME but also wakes suspended system.  */
-#   define CLOCK_BOOTTIME_ALARM		9
+# define CLOCK_BOOTTIME_ALARM		9
 /* Like CLOCK_REALTIME but in International Atomic Time.  */
-#   define CLOCK_TAI			11
+# define CLOCK_TAI			11
 
 /* Flag to indicate time is absolute.  */
-#   define TIMER_ABSTIME		1
-#  endif
+# define TIMER_ABSTIME			1
+#endif
 
-#  ifdef __USE_GNU
-#   include <bits/timex.h>
+#ifdef __USE_GNU
+# include <bits/timex.h>
 
 __BEGIN_DECLS
 
@@ -93,9 +78,6 @@ __BEGIN_DECLS
 extern int clock_adjtime (__clockid_t __clock_id, struct timex *__utx) __THROW;
 
 __END_DECLS
-#  endif /* use GNU */
-
-# endif	/* bits/time.h */
-#endif
+#endif /* use GNU */
 
-#undef __need_timeval
+#endif	/* bits/time.h */
diff --git a/sysdeps/unix/sysv/linux/bits/timex.h b/sysdeps/unix/sysv/linux/bits/timex.h
index 5eb7ccbd2e..1bf6121d88 100644
--- a/sysdeps/unix/sysv/linux/bits/timex.h
+++ b/sysdeps/unix/sysv/linux/bits/timex.h
@@ -19,6 +19,7 @@
 #define	_BITS_TIMEX_H	1
 
 #include <bits/types.h>
+#include <bits/types/struct_timeval.h>
 
 /* These definitions from linux/timex.h as of 3.18.  */