[Bug gcov-profile/52627] New: [4.8 Regression] Build of libgcc fails w/o __GTHREAD_MUTEX_INIT: error: 'mx' undeclared

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52627

             Bug #: 52627
           Summary: [4.8 Regression] Build of libgcc fails w/o
                    __GTHREAD_MUTEX_INIT: error: 'mx' undeclared
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: build
          Severity: normal
          Priority: P3
         Component: gcov-profile
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
                CC: rguenth@gcc.gnu.org
             Build: i586-pc-mingw32


On i586-pc-mingw32, one gets the following failure:

../../../gcc-trunk/libgcc/libgcov.c: In function 'init_mx':
../../../gcc-trunk/libgcc/libgcov.c:716:35: error: 'mx' undeclared (first use
in this function)
../../../gcc-trunk/libgcc/libgcov.c:716:35: note: each undeclared identifier is
reported only once for each function it appears in


The source code has the following - and unless it is declared in an #include
file, no global "mx" variable exists. "grep -w mx" find just line 716:

   707  #ifdef __GTHREAD_MUTEX_INIT
   708  ATTRIBUTE_HIDDEN __gthread_mutex_t __gcov_flush_mx =
__GTHREAD_MUTEX_INIT;
   709  #define init_mx_once()
   710  #else
   711  __gthread_mutex_t __gcov_flush_mx ATTRIBUTE_HIDDEN;
   712  
   713  static void
   714  init_mx (void)
   715  {
   716    __GTHREAD_MUTEX_INIT_FUNCTION (&mx);
   717  }


The code has been added by the commit:
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185231

    2012-03-12  Richard Guenther  <rguenther@suse.de>

        * gthr.h (__GTHREAD_MUTEX_INIT_FUNCTION): Adjust specification.
        * gthr-posix.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
        (__gthread_mutex_init_function): New function.
        * gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.

        PR gcov/49484
        * libgcov.c: Include gthr.h.
        (__gcov_flush_mx): New global variable.
        (init_mx, init_mx_once): New functions.
        (__gcov_flush): Protect self with a mutex.
        (__gcov_fork): Re-initialize mutex after forking.
        * unwind-dw2-fde.c: Change condition under which to use
        __GTHREAD_MUTEX_INIT_FUNCTION.