[Bug-gnulib] obstack.h: a minor const-correctness change

[Jim Meyering]

I've just checked in this change.
Without it, I'd get a warning for a use of obstack_object_size
in coreutils/src/remove.c.

        * obstack.h (obstack_object_size): Declare temporary, __o,
        to be const, in order to avoid warnings.
        (obstack_room): Likewise.
        (obstack_empty_p): Likewise.

Index: obstack.h
===================================================================
RCS file: /fetish/cu/lib/obstack.h,v
retrieving revision 1.17
retrieving revision 1.18
diff -u -p -u -r1.17 -r1.18
--- obstack.h   18 Nov 2000 09:53:33 -0000      1.17
+++ obstack.h   20 Jan 2003 15:45:53 -0000      1.18
@@ -368,12 +368,12 @@ extern int obstack_exit_failure;
 
 # define obstack_object_size(OBSTACK)                                  \
   __extension__                                                                
\
-  ({ struct obstack *__o = (OBSTACK);                                  \
+  ({ struct obstack const *__o = (OBSTACK);                            \
      (unsigned) (__o->next_free - __o->object_base); })
 
 # define obstack_room(OBSTACK)                                         \
   __extension__                                                                
\
-  ({ struct obstack *__o = (OBSTACK);                                  \
+  ({ struct obstack const *__o = (OBSTACK);                            \
      (unsigned) (__o->chunk_limit - __o->next_free); })
 
 # define obstack_make_room(OBSTACK,length)                             \
@@ -386,7 +386,7 @@ __extension__                                               
                \
 
 # define obstack_empty_p(OBSTACK)                                      \
   __extension__                                                                
\
-  ({ struct obstack *__o = (OBSTACK);                                  \
+  ({ struct obstack const *__o = (OBSTACK);                            \
      (__o->chunk->prev == 0 && __o->next_free - __o->chunk->contents == 0); })
 
 # define obstack_grow(OBSTACK,where,length)                            \