Remove MAIN_THREAD flag in GC_thread

(refactoring)

* darwin_stop_world.c (GC_stack_range_for): Do not check MAIN_THREAD
bit of p->flags.
* pthread_stop_world.c (GC_push_all_stacks): Likewise.
* pthread_support.c [!GC_WIN32_THREADS] (GC_set_stackbottom,
GC_get_my_stackbottom): Likewise.
* pthread_support.c [!GC_WIN32_THREADS] (GC_call_with_gc_active):
Likewise.
* darwin_stop_world.c (GC_stack_range_for): Do not use GC_stackbottom.
* pthread_stop_world.c (GC_push_all_stacks): Likewise.
* pthread_support.c [!GC_WIN32_THREADS] (GC_get_my_stackbottom):
Likewise.
* dyn_load.c [(SCO_ELF || DGUX || HURD || NACL || __ELF__ && (LINUX
|| FREEBSD || NETBSD || OPENBSD)) && USE_PROC_FOR_LIBRARIES]
(GC_register_map_entries): Do not check GC_stackbottom if THREADS.
* include/gc/gc.h (GC_stackbottom): Refine comment (mention that it
could be change only before GC initialization if multi-threaded,
mention GC_set_stackbottom).
* include/private/gcconfig.h [IA64 && (HPUX || LINUX)]
(BACKING_STORE_BASE): Remove.
* include/private/pthread_support.h [!GC_WIN32_THREADS] (MAIN_THREAD):
Likewise.
* mark_rts.c [!THREADS && IA64] (GC_push_current_stack): Use
GC_register_stackbottom instead of BACKING_STORE_BASE.
* pthread_stop_world.c [IA64] (GC_push_all_stacks): Do not use
BACKING_STORE_BASE (GC_register_stackbottom).
* pthread_support.c [!GC_WIN32_THREADS] (GC_thr_init): Do not set
MAIN_THREAD bit of me->flags.
* pthread_support.c (GC_set_stackbottom, GC_get_my_stackbottom): Move
crtn local variable to outer scope.
* pthread_support.c [!GC_WIN32_THREADS] (GC_set_stackbottom): Do not
set GC_stackbottom (and GC_register_stackbottom) if GC is initialized.
* pthread_support.c [!GC_WIN32_THREADS && IA64]
(GC_get_my_stackbottom): Do not use GC_register_stackbottom.
* pthread_support.c (GC_call_with_gc_active): Move stack_end local
variable to outer scope.
* pthread_support.c [!GC_WIN32_THREADS] (GC_call_with_gc_active): Do
not use and set GC_stackbottom.

3 files changed, 9 insertions, 10 deletions

diff --git a/include/gc/gc.h b/include/gc/gc.h
index 811add18..bf64d2d9 100644
--- a/include/gc/gc.h
+++ b/include/gc/gc.h
@@ -382,11 +382,15 @@ GC_API GC_ATTR_DEPRECATED char *GC_stackbottom;
                                 /* potentially some signals that can    */
                                 /* confuse debuggers.  Otherwise the    */
                                 /* collector attempts to set it         */
-                                /* automatically.                       */
-                                /* For multi-threaded code, this is the */
-                                /* cold end of the stack for the        */
-                                /* primordial thread.  Portable clients */
-                                /* should use GC_get_stack_base(),      */
+                                /* automatically.  For multi-threaded   */
+                                /* code, this is the cold end of the    */
+                                /* stack for the primordial thread.     */
+                                /* For multi-threaded code, altering    */
+                                /* GC_stackbottom value directly after  */
+                                /* GC initialization has no effect.     */
+                                /* Portable clients should use          */
+                                /* GC_set_stackbottom(),                */
+                                /* GC_get_stack_base(),                 */
                                 /* GC_call_with_gc_active() and         */
                                 /* GC_register_my_thread() instead.     */
 
diff --git a/include/private/gcconfig.h b/include/private/gcconfig.h
index 839f0ef1..1f25e5c1 100644
--- a/include/private/gcconfig.h
+++ b/include/private/gcconfig.h
@@ -1851,7 +1851,6 @@ EXTERN_C_BEGIN
         /* address minus one page.                                      */
 #       define BACKING_STORE_DISPLACEMENT 0x1000000
 #       define BACKING_STORE_ALIGNMENT 0x1000
-#       define BACKING_STORE_BASE GC_register_stackbottom
         /* Known to be wrong for recent HP/UX versions!!!       */
 #   endif
 #   ifdef LINUX
@@ -1861,7 +1860,6 @@ EXTERN_C_BEGIN
         /* TODO: LINUX_STACKBOTTOM does not work on NUE.        */
         /* We also need the base address of the register stack  */
         /* backing store.                                       */
-#       define BACKING_STORE_BASE GC_register_stackbottom
 #       define SEARCH_FOR_DATA_START
 #       ifdef __GNUC__
 #         define DYNAMIC_LOADING
diff --git a/include/private/pthread_support.h b/include/private/pthread_support.h
index dab3738b..091e153e 100644
--- a/include/private/pthread_support.h
+++ b/include/private/pthread_support.h
@@ -184,9 +184,6 @@ typedef struct GC_Thread_Rep {
                                 /* it unregisters itself, since it      */
                                 /* may not return a GC pointer.         */
 # endif
-# ifndef GC_WIN32_THREADS
-#   define MAIN_THREAD  0x4     /* True for the original thread only.   */
-# endif
 # if (defined(GC_HAVE_PTHREAD_EXIT) || !defined(GC_NO_PTHREAD_CANCEL)) \
      && defined(GC_PTHREADS)
 #   define DISABLED_GC  0x10    /* Collections are disabled while the   */