dnl configure fragment for new libpthread implementation.GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.if test "x$libc_cv_gcc___thread" != xyes; then  AC_MSG_ERROR(compiler support for __thread is required)fiif test "x${libc_cv_visibility_attribute}" != xyes ||   test "x${libc_cv_broken_visibility_attribute}" != xno; then  AC_MSG_ERROR(working compiler support for visibility attribute is required)fiif test "x$libc_cv_asm_cfi_directives" != xyes; then  dnl We need this only for some architectures.  case "$base_machine" in    i386 | x86_64 | powerpc | s390)      AC_MSG_ERROR(CFI directive support in assembler is required) ;;    *) ;;  esacfidnl Iff <unwind.h> is available, make sure it is the right one and itdnl contains struct _Unwind_Exception.AC_CACHE_CHECK(dnlfor forced unwind support, libc_cv_forced_unwind, [dnlAC_TRY_LINK([#include <unwind.h>], [struct _Unwind_Exception exc;struct _Unwind_Context *context;_Unwind_GetCFA (context)],libc_cv_forced_unwind=yes, libc_cv_forced_unwind=no)])if test $libc_cv_forced_unwind = yes; then  AC_DEFINE(HAVE_FORCED_UNWIND)dnl Check for C cleanup handling.  old_CFLAGS="$CFLAGS"  CFLAGS="$CFLAGS -Werror -fexceptions"  AC_CACHE_CHECK([for C cleanup handling], libc_cv_c_cleanup, [dnl  AC_TRY_LINK([#include <stdio.h>void cl (void *a) { }], [  int a __attribute__ ((cleanup (cl)));  puts ("test")],libc_cv_c_cleanup=yes, libc_cv_c_cleanup=no)])  CFLAGS="$old_CFLAGS"  if test $libc_cv_c_cleanup = no; then    AC_MSG_ERROR([the compiler must support C cleanup handling])  fielse  AC_MSG_ERROR(forced unwind support is required)fi