Use global atexit data for all configurations

For the exit processing only members of _GLOBAL_REENT were used by default.  If
the _REENT_GLOBAL_ATEXIT option was enabled, then the data structures were
provided through dedicated global objects.  Make this option the default.
Remove the option.  Rename struct _reent members _atexit and _atexit0 to
_reserved_6 and _reserved_7, respectively.  Provide them only if
_REENT_BACKWARD_BINARY_COMPAT is defined.

12 files changed, 46 insertions, 107 deletions

diff --git a/libgloss/arc/crt0.S b/libgloss/arc/crt0.S
index 46c9efd71..8d9adaa52 100644
--- a/libgloss/arc/crt0.S
+++ b/libgloss/arc/crt0.S
@@ -187,12 +187,13 @@ __start:
 	; calling atexit drags in malloc, so instead poke the function
 	; address directly into the reent structure
 	ld	r1, [gp, @_impure_ptr@sda]
-	mov_s	r0, @_fini
-	add	r1, r1, 0x14c		; &_GLOBAL_REENT->atexit0
-	st	r1, [r1, -4]		; _GLOBAL_REENT->atexit
-	st_s	r0, [r1, 8]		; _GLOBAL_REENT->atexit0._fns[0]
+	mov_s	r1, @__atexit0
+	mov_s	r2, @__atexit
+	st_s	r1, [r2, 0]		; __atexit = &__atexit0
 	mov_s	r0, 1
-	st_s	r0, [r1, 4]		; _GLOBAL_REENT->atexit0._ind
+	st_s	r0, [r1, 4]		; __atexit0._ind = 1
+	mov_s	r0, @_fini
+	st_s	r0, [r1, 8]		; __atexit0._fns[0] = _fini
 ; branch to _init
 #if defined (__ARCEM__) || defined (__ARCHS__)
 	jl	@_init
diff --git a/libgloss/epiphany/crt0.S b/libgloss/epiphany/crt0.S
index d684e1e10..b0d9ecbab 100644
--- a/libgloss/epiphany/crt0.S
+++ b/libgloss/epiphany/crt0.S
@@ -113,23 +113,19 @@ _external_start:
 #else
 	; calling atexit drags in malloc, so instead poke the function
 	; address directly into the reent structure
-	mov	r2,%low(__impure_ptr)
-	movt	r2,%high(__impure_ptr)
-	ldr	r2,[r2]
-	mov	r1,%low(fini)
-	movt	r1,%high(fini)
+	mov	r1,%low(__atexit0)
+	movt	r1,%high(__atexit0)
+	mov	r2,%low(__atexit)
+	movt	r2,%high(__atexit)
 #ifdef __STRUCT_ALIGN_64__
-#error
-	add	r2,r2,need_to_find_out; &_GLOBAL_REENT->atexit0
-	str	r2, [r2,-1];??or -2?; _GLOBAL_REENT->atexit
-	mov	r0, 1
-	str	r0, [r2,1]	; _GLOBAL_REENT->atexit0._ind
-	str	r1, [r2,2]	; _GLOBAL_REENT->atexit0._fns[0]
+#error "not implemented"
 #else  /* !__STRUCT_ALIGN_64__ */
-	add	r0,r2,0x14c	; &_GLOBAL_REENT->atexit0
-	str	r0, [r0,-1]	; _GLOBAL_REENT->atexit
-	mov	r0, 1
-	strd	r0, [r2,0x2a]	; _GLOBAL_REENT->atexit0._ind
+	str	r1, [r2, 0]	; __atexit = &__atexit0
+	movr	r0, 1
+	str	r0, [r1, 4]	; __atexit0._ind = 1
+	mov	r0,%low(fini)
+	movt	r0,%high(fini)
+	str	r0, [r1, 8]	; __atexit0._fns[0] = fini
 #endif /* !__STRUCT_ALIGN_64__ */
 #endif /* !0 */
 	;; Call global and static constructors
diff --git a/libgloss/sparc_leon/locore_atexit.c b/libgloss/sparc_leon/locore_atexit.c
index b23054c77..e3e6df12f 100644
--- a/libgloss/sparc_leon/locore_atexit.c
+++ b/libgloss/sparc_leon/locore_atexit.c
@@ -37,9 +37,9 @@ atexit (void (*fn) (void))
 {
   register struct _atexit *p;
 
-  p = _GLOBAL_REENT->_atexit;
+  p = __atexit;
   if (p == NULL)
-    _GLOBAL_REENT->_atexit = p = &_GLOBAL_REENT->_atexit0;
+    __atexit = p = &__atexit0;
   if (p->_ind >= _ATEXIT_SIZE)
     {
       return -1;
diff --git a/newlib/README b/newlib/README
index 9de294e9c..f00e66019 100644
--- a/newlib/README
+++ b/newlib/README
@@ -294,12 +294,6 @@ One feature can be enabled by specifying `--enable-FEATURE=yes' or
      Disable dynamic allocation of atexit entries.
      Most hosts and targets have it enabled in configure.host.
 
-`--enable-newlib-global-atexit'
-     Enable atexit data structure as global variable.  By doing so it is
-     move out of _reent structure, and can be garbage collected if atexit
-     is not referenced.
-     Disabled by default.
-
 `--enable-newlib-global-stdio-streams'
      Enable to move the stdio stream FILE objects out of struct _reent and make
      them global.  The stdio stream pointers of struct _reent are initialized
diff --git a/newlib/configure b/newlib/configure
index 60cbc1fa8..aa12fdce0 100755
--- a/newlib/configure
+++ b/newlib/configure
@@ -2373,12 +2373,11 @@ if test "${enable_newlib_global_atexit+set}" = set; then :
   enableval=$enable_newlib_global_atexit; if test "${newlib_global_atexit+set}" != set; then
   case "${enableval}" in
     yes) newlib_global_atexit=yes ;;
-    no)  newlib_global_atexit=no  ;;
     *)   as_fn_error $? "bad value ${enableval} for newlib-global-atexit option" "$LINENO" 5 ;;
   esac
  fi
 else
-  newlib_global_atexit=no
+  newlib_global_atexit=yes
 fi
 
 # Check whether --enable-newlib-reent-small was given.
@@ -6484,12 +6483,6 @@ $as_echo "#define _ATEXIT_DYNAMIC_ALLOC 1" >>confdefs.h
 
 fi
 
-if test "${newlib_global_atexit}" = "yes"; then
-
-$as_echo "#define _REENT_GLOBAL_ATEXIT 1" >>confdefs.h
-
-fi
-
 if test "${newlib_fvwrite_in_streamio}" = "yes"; then
 
 $as_echo "#define _FVWRITE_IN_STREAMIO 1" >>confdefs.h
diff --git a/newlib/configure.ac b/newlib/configure.ac
index 12d52c262..57f830960 100644
--- a/newlib/configure.ac
+++ b/newlib/configure.ac
@@ -142,16 +142,16 @@ AC_ARG_ENABLE(newlib-atexit-dynamic-alloc,
 
 dnl Support --enable-newlib-global-atexit
 dnl Enable atexit data structure as global variables to save memory usage in
-dnl _reent.
+dnl _reent.  This is no longer optional.  It is enabled in all Newlib
+dnl configurations.
 AC_ARG_ENABLE(newlib-global-atexit,
 [  --enable-newlib-global-atexit	enable atexit data structure as global],
 [if test "${newlib_global_atexit+set}" != set; then
   case "${enableval}" in
     yes) newlib_global_atexit=yes ;;
-    no)  newlib_global_atexit=no  ;;
     *)   AC_MSG_ERROR(bad value ${enableval} for newlib-global-atexit option) ;;
   esac
- fi], [newlib_global_atexit=no])dnl
+ fi], [newlib_global_atexit=yes])dnl
 
 dnl Support --enable-newlib-reent-small
 AC_ARG_ENABLE(newlib-reent-small,
@@ -470,10 +470,6 @@ if test "${newlib_atexit_dynamic_alloc}" = "yes"; then
   AC_DEFINE(_ATEXIT_DYNAMIC_ALLOC, 1, [If atexit() may dynamically allocate space for cleanup functions.])
 fi
 
-if test "${newlib_global_atexit}" = "yes"; then
-  AC_DEFINE(_REENT_GLOBAL_ATEXIT, 1, [Define if declare atexit data as global.])
-fi
-
 if test "${newlib_fvwrite_in_streamio}" = "yes"; then
   AC_DEFINE(_FVWRITE_IN_STREAMIO, 1, [Define if ivo supported in streamio.])
 fi
diff --git a/newlib/libc/include/sys/config.h b/newlib/libc/include/sys/config.h
index b4d755957..c40bb51c2 100644
--- a/newlib/libc/include/sys/config.h
+++ b/newlib/libc/include/sys/config.h
@@ -242,7 +242,6 @@
 #define __FILENAME_MAX__ 255
 #define _READ_WRITE_RETURN_TYPE _ssize_t
 #define __DYNAMIC_REENT__
-#define _REENT_GLOBAL_ATEXIT
 #define _REENT_GLOBAL_STDIO_STREAMS
 #endif
 
diff --git a/newlib/libc/include/sys/reent.h b/newlib/libc/include/sys/reent.h
index b99cfe099..4a3cfbd34 100644
--- a/newlib/libc/include/sys/reent.h
+++ b/newlib/libc/include/sys/reent.h
@@ -105,13 +105,6 @@ struct _atexit {
 # define _ATEXIT_INIT {_NULL, 0, {_NULL}, {{_NULL}, {_NULL}, 0, 0}}
 #endif
 
-#ifdef _REENT_GLOBAL_ATEXIT
-# define _REENT_INIT_ATEXIT
-#else
-# define _REENT_INIT_ATEXIT \
-  _NULL, _ATEXIT_INIT,
-#endif
-
 /*
  * Stdio buffers.
  *
@@ -346,10 +339,12 @@ struct _rand48 {
 #define _REENT_INIT_RESERVED_0 0,
 #define _REENT_INIT_RESERVED_1 0,
 #define _REENT_INIT_RESERVED_2 0,
+#define _REENT_INIT_RESERVED_6_7 _NULL, _ATEXIT_INIT,
 #else
 #define _REENT_INIT_RESERVED_0 /* Nothing to initialize */
 #define _REENT_INIT_RESERVED_1 /* Nothing to initialize */
 #define _REENT_INIT_RESERVED_2 /* Nothing to initialize */
+#define _REENT_INIT_RESERVED_6_7 /* Nothing to initialize */
 #endif
 
 /*
@@ -428,11 +423,10 @@ struct _reent
   /* signal info */
   void (**(_sig_func))(int);
 
-# ifndef _REENT_GLOBAL_ATEXIT
-  /* atexit stuff */
-  struct _atexit *_atexit;
-  struct _atexit _atexit0;
-# endif
+#ifdef _REENT_BACKWARD_BINARY_COMPAT
+  struct _atexit *_reserved_6;
+  struct _atexit _reserved_7;
+#endif
 
   struct _glue __sglue;			/* root of glue chain */
   __FILE *__sf;			        /* file descriptors */
@@ -461,7 +455,7 @@ struct _reent
     _NULL, \
     _NULL, \
     _NULL, \
-    _REENT_INIT_ATEXIT \
+    _REENT_INIT_RESERVED_6_7 \
     {_NULL, 0, _NULL}, \
     _NULL, \
     _NULL, \
@@ -499,7 +493,7 @@ extern const struct __sFILE_fake __sf_fake_stderr;
     _NULL, \
     _NULL, \
     _NULL, \
-    _REENT_INIT_ATEXIT \
+    _REENT_INIT_RESERVED_6_7 \
     {_NULL, 0, _NULL}, \
     _NULL, \
     _NULL, \
@@ -694,11 +688,10 @@ struct _reent
 #endif
     } _new;
 
-# ifndef _REENT_GLOBAL_ATEXIT
-  /* atexit stuff */
-  struct _atexit *_atexit;	/* points to head of LIFO stack */
-  struct _atexit _atexit0;	/* one guaranteed table, required by ANSI */
-# endif
+#ifdef _REENT_BACKWARD_BINARY_COMPAT
+  struct _atexit *_reserved_6;
+  struct _atexit _reserved_7;
+#endif
 
   /* signal info */
   void (**_sig_func)(int);
@@ -767,7 +760,7 @@ struct _reent
         {0, {0}} \
       } \
     }, \
-    _REENT_INIT_ATEXIT \
+    _REENT_INIT_RESERVED_6_7 \
     _NULL \
     _REENT_INIT_SGLUE(&(var)) \
   }
@@ -869,12 +862,8 @@ extern int _fwalk_sglue (struct _reent *, int (*)(struct _reent *, __FILE *),
 
 #define _GLOBAL_REENT (&_impure_data)
 
-#ifdef _REENT_GLOBAL_ATEXIT
-extern struct _atexit *_global_atexit; /* points to head of LIFO stack */
-# define _GLOBAL_ATEXIT _global_atexit
-#else
-# define _GLOBAL_ATEXIT (_GLOBAL_REENT->_atexit)
-#endif
+extern struct _atexit *__atexit; /* points to head of LIFO stack */
+extern struct _atexit __atexit0; /* one guaranteed table, required by ANSI */
 
 #ifdef __cplusplus
 }
diff --git a/newlib/libc/reent/reent.c b/newlib/libc/reent/reent.c
index 70f1c5f45..04942ce4d 100644
--- a/newlib/libc/reent/reent.c
+++ b/newlib/libc/reent/reent.c
@@ -93,25 +93,6 @@ _reclaim_reent (struct _reent *ptr)
 	_free_r (ptr, ptr->_misc);
 #endif
 
-#ifndef _REENT_GLOBAL_ATEXIT
-      /* atexit stuff */
-# ifdef _REENT_SMALL
-      if (ptr->_atexit && ptr->_atexit->_on_exit_args_ptr)
-	_free_r (ptr, ptr->_atexit->_on_exit_args_ptr);
-# else
-      if ((ptr->_atexit) && (ptr->_atexit != &ptr->_atexit0))
-	{
-	  struct _atexit *p, *q;
-	  for (p = ptr->_atexit; p != &ptr->_atexit0;)
-	    {
-	      q = p;
-	      p = p->_next;
-	      _free_r (ptr, q);
-	    }
-	}
-# endif
-#endif
-
       if (ptr->_cvtbuf)
 	_free_r (ptr, ptr->_cvtbuf);
     /* We should free _sig_func to avoid a memory leak, but how to
diff --git a/newlib/libc/stdlib/__atexit.c b/newlib/libc/stdlib/__atexit.c
index ed7af4200..e59f04c2e 100644
--- a/newlib/libc/stdlib/__atexit.c
+++ b/newlib/libc/stdlib/__atexit.c
@@ -53,12 +53,7 @@ const void * __atexit_dummy = &__call_exitprocs;
 extern _LOCK_RECURSIVE_T __atexit_recursive_mutex;
 #endif
 
-#ifdef _REENT_GLOBAL_ATEXIT
-static struct _atexit _global_atexit0 = _ATEXIT_INIT;
-# define _GLOBAL_ATEXIT0 (&_global_atexit0)
-#else
-# define _GLOBAL_ATEXIT0 (&_GLOBAL_REENT->_atexit0)
-#endif
+struct _atexit __atexit0 = _ATEXIT_INIT;
 
 /*
  * Register a function to be performed at exit or on shared library unload.
@@ -77,10 +72,10 @@ __register_exitproc (int type,
   __lock_acquire_recursive(__atexit_recursive_mutex);
 #endif
 
-  p = _GLOBAL_ATEXIT;
+  p = __atexit;
   if (p == NULL)
     {
-      _GLOBAL_ATEXIT = p = _GLOBAL_ATEXIT0;
+      __atexit = p = &__atexit0;
 #ifdef _REENT_SMALL
       extern struct _on_exit_args * const __on_exit_args _ATTRIBUTE ((weak));
       if (&__on_exit_args != NULL)
@@ -104,8 +99,8 @@ __register_exitproc (int type,
 	  return -1;
 	}
       p->_ind = 0;
-      p->_next = _GLOBAL_ATEXIT;
-      _GLOBAL_ATEXIT = p;
+      p->_next = __atexit;
+      __atexit = p;
 #ifndef _REENT_SMALL
       p->_on_exit_args._fntypes = 0;
       p->_on_exit_args._is_cxa = 0;
diff --git a/newlib/libc/stdlib/__call_atexit.c b/newlib/libc/stdlib/__call_atexit.c
index c29a03c8e..710440389 100644
--- a/newlib/libc/stdlib/__call_atexit.c
+++ b/newlib/libc/stdlib/__call_atexit.c
@@ -17,9 +17,7 @@ void free(void *) _ATTRIBUTE((__weak__));
 __LOCK_INIT_RECURSIVE(, __atexit_recursive_mutex);
 #endif
 
-#ifdef _REENT_GLOBAL_ATEXIT
-struct _atexit *_global_atexit = _NULL;
-#endif
+struct _atexit *__atexit = _NULL;
 
 #ifdef _WANT_REGISTER_FINI
 
@@ -83,8 +81,8 @@ __call_exitprocs (int code, void *d)
 
  restart:
 
-  p = _GLOBAL_ATEXIT;
-  lastp = &_GLOBAL_ATEXIT;
+  p = __atexit;
+  lastp = &__atexit;
   while (p)
     {
 #ifdef _REENT_SMALL
diff --git a/newlib/newlib.hin b/newlib/newlib.hin
index 4a9614970..718e5d970 100644
--- a/newlib/newlib.hin
+++ b/newlib/newlib.hin
@@ -378,9 +378,6 @@
 /* Verify _REENT_CHECK macros allocate memory successfully. */
 #undef _REENT_CHECK_VERIFY
 
-/* Define if declare atexit data as global. */
-#undef _REENT_GLOBAL_ATEXIT
-
 /* Define if using retargetable functions for default lock routines. */
 #undef _RETARGETABLE_LOCKING