Re: [Bug-gnulib] obstack uses casts as lvalues

[Paul Eggert]

I installed the following further cleanup patch to gnulib obstack.h
and obstack.c, to make it easier to merge gnulib's changes into libc
in the future.

2003-10-21  Paul Eggert  <address@hidden>

        * obstack.c: Merge from glibc.
        [defined _LIBC]: Include <obstack.h>, not "obstack.h".
        Add libc_hidden_def (_obstack_newchunk).
        (_obstack_free) [! defined _LIBC]: Remove.
        [defined _LIBC]: Make a strong alias from obstack_free, rather than
        a clone of the function body.
        (fputs) [defined _LIBC && defined USE_IN_LIBIO]: Remove.
        [defined _LIBC && !defined USE_IN_LIBIO]: Include <libio/iolibio.h>.

        * obstack.h: Indenting cleanup, to make it easier to merge with glibc.
        (obstack_grow, obstack_grow0): Remove unnecessary parentheses around
        arg to memcpy.

Index: lib/obstack.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/obstack.c,v
retrieving revision 1.21
diff -p -u -r1.21 obstack.c
--- lib/obstack.c       12 Sep 2003 20:14:10 -0000      1.21
+++ lib/obstack.c       22 Oct 2003 05:07:18 -0000
@@ -21,7 +21,11 @@
 # include <config.h>
 #endif
 
+#ifdef _LIBC
+#include <obstack.h>
+#else
 #include "obstack.h"
+#endif
 
 /* NOTE BEFORE MODIFYING THIS FILE: This version number must be
    incremented whenever callers compiled using an old obstack.h can no
@@ -282,6 +286,9 @@ _obstack_newchunk (struct obstack *h, in
   /* The new chunk certainly contains no empty object yet.  */
   h->maybe_empty_object = 0;
 }
+#ifdef _LIBC
+libc_hidden_def (_obstack_newchunk)
+#endif
 
 /* Return nonzero if object OBJ has been allocated from obstack H.
    This is here for debugging.
@@ -314,41 +321,6 @@ _obstack_allocated_p (struct obstack *h,
 
 # undef obstack_free
 
-/* This function has two names with identical definitions.
-   This is the first one, called from non-ANSI code.  */
-
-void
-_obstack_free (struct obstack *h, void *obj)
-{
-  register struct _obstack_chunk *lp;  /* below addr of any objects in this 
chunk */
-  register struct _obstack_chunk *plp; /* point to previous chunk if any */
-
-  lp = h->chunk;
-  /* We use >= because there cannot be an object at the beginning of a chunk.
-     But there can be an empty object at that address
-     at the end of another chunk.  */
-  while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
-    {
-      plp = lp->prev;
-      CALL_FREEFUN (h, lp);
-      lp = plp;
-      /* If we switch chunks, we can't tell whether the new current
-        chunk contains an empty object, so assume that it may.  */
-      h->maybe_empty_object = 1;
-    }
-  if (lp)
-    {
-      h->object_base = h->next_free = (char *) (obj);
-      h->chunk_limit = lp->limit;
-      h->chunk = lp;
-    }
-  else if (obj != 0)
-    /* obj is not in any of the chunks! */
-    abort ();
-}
-
-/* This function is used from ANSI code.  */
-
 void
 obstack_free (struct obstack *h, void *obj)
 {
@@ -378,6 +350,12 @@ obstack_free (struct obstack *h, void *o
     /* obj is not in any of the chunks! */
     abort ();
 }
+
+#ifdef _LIBC
+/* Older versions of libc used a function _obstack_free intended to be
+   called by non-GCC compilers.  */
+strong_alias (obstack_free, _obstack_free)
+#endif
 
 int
 _obstack_memory_used (struct obstack *h)
@@ -400,9 +378,8 @@ _obstack_memory_used (struct obstack *h)
 # endif
 # define _(msgid) gettext (msgid)
 
-# if defined _LIBC && defined USE_IN_LIBIO
+# ifdef _LIBC
 #  include <libio/iolibio.h>
-#  define fputs(s, f) _IO_fputs (s, f)
 # endif
 
 # ifndef __attribute__
Index: lib/obstack.h
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/obstack.h,v
retrieving revision 1.24
diff -p -u -r1.24 obstack.h
--- lib/obstack.h       22 Oct 2003 01:02:48 -0000      1.24
+++ lib/obstack.h       22 Oct 2003 05:07:18 -0000
@@ -248,30 +248,30 @@ extern int obstack_exit_failure;
 #define obstack_alignment_mask(h) ((h)->alignment_mask)
 
 /* To prevent prototype warnings provide complete argument list.  */
-# define obstack_init(h)                                       \
+#define obstack_init(h)                                                \
   _obstack_begin ((h), 0, 0,                                   \
                  (void *(*) (long)) obstack_chunk_alloc,       \
                  (void (*) (void *)) obstack_chunk_free)
 
-# define obstack_begin(h, size)                                        \
+#define obstack_begin(h, size)                                 \
   _obstack_begin ((h), (size), 0,                              \
                  (void *(*) (long)) obstack_chunk_alloc,       \
                  (void (*) (void *)) obstack_chunk_free)
 
-# define obstack_specify_allocation(h, size, alignment, chunkfun, freefun) \
+#define obstack_specify_allocation(h, size, alignment, chunkfun, freefun)  \
   _obstack_begin ((h), (size), (alignment),                               \
                  (void *(*) (long)) (chunkfun),                           \
                  (void (*) (void *)) (freefun))
 
-# define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, 
freefun, arg) \
+#define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, 
freefun, arg) \
   _obstack_begin_1 ((h), (size), (alignment),                          \
                    (void *(*) (void *, long)) (chunkfun),              \
                    (void (*) (void *, void *)) (freefun), (arg))
 
-# define obstack_chunkfun(h, newchunkfun) \
+#define obstack_chunkfun(h, newchunkfun) \
   ((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))
 
-# define obstack_freefun(h, newfreefun) \
+#define obstack_freefun(h, newfreefun) \
   ((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
 
 #define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))
@@ -322,7 +322,7 @@ __extension__                                               
                \
    int __len = (length);                                               \
    if (__o->next_free + __len > __o->chunk_limit)                      \
      _obstack_newchunk (__o, __len);                                   \
-   memcpy (__o->next_free, (where), __len);                            \
+   memcpy (__o->next_free, where, __len);                              \
    __o->next_free += __len;                                            \
    (void) 0; })
 
@@ -332,7 +332,7 @@ __extension__                                               
                \
    int __len = (length);                                               \
    if (__o->next_free + __len + 1 > __o->chunk_limit)                  \
      _obstack_newchunk (__o, __len + 1);                               \
-   memcpy (__o->next_free, (where), __len);                            \
+   memcpy (__o->next_free, where, __len);                              \
    __o->next_free += __len;                                            \
    *(__o->next_free)++ = 0;                                            \
    (void) 0; })
@@ -456,14 +456,14 @@ __extension__                                             
                \
 ( (h)->temp = (length),                                                        
\
   (((h)->next_free + (h)->temp > (h)->chunk_limit)                     \
    ? (_obstack_newchunk ((h), (h)->temp), 0) : 0),                     \
-  memcpy ((h)->next_free, (where), (h)->temp),                         \
+  memcpy ((h)->next_free, where, (h)->temp),                           \
   (h)->next_free += (h)->temp)
 
 # define obstack_grow0(h,where,length)                                 \
 ( (h)->temp = (length),                                                        
\
   (((h)->next_free + (h)->temp + 1 > (h)->chunk_limit)                 \
    ? (_obstack_newchunk ((h), (h)->temp + 1), 0) : 0),                 \
-  memcpy ((h)->next_free, (where), (h)->temp),                         \
+  memcpy ((h)->next_free, where, (h)->temp),                           \
   (h)->next_free += (h)->temp,                                         \
   *((h)->next_free)++ = 0)
 
@@ -517,7 +517,7 @@ __extension__                                               
                \
   (h)->object_base = (h)->next_free,                                   \
   (void *) __INT_TO_PTR ((h)->temp))
 
-#  define obstack_free(h,obj)                                          \
+# define obstack_free(h,obj)                                           \
 ( (h)->temp = (char *) (obj) - (char *) (h)->chunk,                    \
   (((h)->temp > 0 && (h)->temp < (h)->chunk_limit - (char *) (h)->chunk)\
    ? (int) ((h)->next_free = (h)->object_base                          \