Allow to omit name in timer_stop

If the argument 'name' is not given to timer_stop, close the currently
active region without further sanity checking.

ftimings/ftimings.F90

@@ -210,12 +210,15 @@ module ftimings
 
   !> End a timing segment, \sa timer_start
   !>
-  !> \param name        The exact same name as was used for %start()
+  !> \param name        The exact same name as was used for %start().
+  !>                    If not provided, close the currently active region.
+  !>                    If given, warns if it does not match the last %start()
+  !>                    call on stderr and disables the current timer instance.
   !>
   !> \implements timer_t::stop
   subroutine timer_stop(self, name)
     class(timer_t), intent(inout), target :: self
-    character(len=*), intent(in) :: name
+    character(len=*), intent(in), optional :: name
     logical :: error
     !$ integer :: omp_get_level, omp_get_ancestor_thread_num
     !$ integer :: i
@@ -235,19 +238,18 @@ module ftimings
     error = .false.
 
     if (.not. associated(self%current_node)) then
-      write(error_unit,'(a)') "Called %stop(""" // trim(name)  // """) without first calling %start(""" // trim(name) // &
-        & """), disabling timings"
-      call self%free()
-      self%active = .false.
-      error = .true.
-    else if (len(trim(name)) == 0) then
-      write(error_unit,'(a)') "Warning: Expected %stop(""" // trim(self%current_node%name)  // """), but got %stop("""")"
-    else if (.not. string_eq(self%current_node%name, name)) then
-      write(error_unit,'(a)') "Expected %stop(""" // trim(self%current_node%name)  // """), but got %stop(""" // trim(name) // &
-        & """), disabling timings"
+      write(error_unit,'(a)') "Called timer_stop() without first calling any timer_start(), disabling timings"
       call self%free()
       self%active = .false.
       error = .true.
+    else if (present(name)) then
+      if (.not. string_eq(self%current_node%name, name)) then
+        write(error_unit,'(a)') "Expected %stop(""" // trim(self%current_node%name)  // """),&
+                 & but got %stop(""" // trim(name) //  """), disabling timings"
+        call self%free()
+        self%active = .false.
+        error = .true.
+      endif
     endif
 
     if (.not. error) then
@@ -255,7 +257,7 @@ module ftimings
 
       ! climb up to parent
       if (.not. associated(self%current_node%parent)) then
-        write(error_unit,'(a)') "Error: No valid parent node found for node '" // trim(name) // "'"
+        write(error_unit,'(a)') "Error: No valid parent node found for node '" // trim(self%current_node%name) // "'"
         call self%free()
         self%active = .false.
       endif