/* obstack.c - subroutines used implicitly by object stack macros
Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
# include "marpa_obs.h"
/* NOTE BEFORE MODIFYING THIS FILE: This version number must be
incremented whenever callers compiled using an old obstack.h can no
longer properly call the functions in this obstack.c. */
/* NOTE FOR MARPA MODIFICATION -- The GNU original has a lot of complex
CPP logic intended to make this file work as part of GNU libc as well
as independently. This was causing me portability problems, with
no value added -- inclusion in the GNU libc is not exactly a near
term priority for libmarpa.
A second complication was the internationalization, which also caused
portability problems. Again, no added value --
there is exactly one message in this file
and in the libmarpa context it will *NEVER* be called -- it's for
memory allocation failures and libmarpa uses g_malloc();
I've removed these complications. Otherwise, I've tried to leave this file intact.
The result may be useful for someone else trying to embed obstack into
their application. On the other hand, it is PROBABLY A VERY BAD IDEA to
simply use this as a drop-in replacement for obstack.c. */
/* ORIGINAL COMMENT:
Comment out all this code if we are using the GNU C Library, and are not
actually compiling the library itself, and the installed library
supports the same library interface we do. This code is part of the GNU
C Library, but also included in many other GNU distributions. Compiling
and linking in this code is a waste when using the GNU C library
(especially if it is a shared library). Rather than having every GNU
program understand `configure --with-gnu-libc' and omit the object
files, it is simpler to just do this in the source for each such file. */
/* NOTE FOR MARPA VERSION: I'm happy to rely on the local versions of the
GNU C and GTK libraries, and sanquine about facing the portability
consequences. But obstacks seem to be in a twilight zone, and until
I understand what's going on better, I'm taking no chances. There is
not a lot of code here, and I'm just going to compile it as part of
libmarpa. -- Jeffrey Kegler
*/
#include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */
#include <stddef.h>
# if HAVE_INTTYPES_H
# include <inttypes.h>
# endif
# if HAVE_STDINT_H
# include <stdint.h>
# endif
/* Determine default alignment. */
union fooround
{
uintmax_t i;
long double d;
void *p;
};
struct fooalign
{
char c;
union fooround u;
};
/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
But in fact it might be less smart and round addresses to as much as
DEFAULT_ROUNDING. So we prepare for it to do that. */
enum
{
DEFAULT_ALIGNMENT = offsetof (struct fooalign, u),
DEFAULT_ROUNDING = sizeof (union fooround)
};
/* When we copy a long block of data, this is the unit to do it with.
On some machines, copying successive ints does not work;
in such a case, redefine COPYING_UNIT to `long' (if that works)
or `char' as a last resort. */
# ifndef COPYING_UNIT
# define COPYING_UNIT int
# endif
# include <stdlib.h>
/* Define a macro that either calls functions with the traditional malloc/free
calling interface, or calls functions with the mmalloc/mfree interface
(that adds an extra first argument), based on the state of use_extra_arg.
For free, do not use ?:, since some compilers, like the MIPS compilers,
do not allow (expr) ? void : void. */
# define CALL_CHUNKFUN(h, size) \
(((h) -> use_extra_arg) \
? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
: (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
# define CALL_FREEFUN(h, old_chunk) \
do { \
if ((h) -> use_extra_arg) \
(*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
else \
(*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
} while (0)
/* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
Objects start on multiples of ALIGNMENT (0 means use default).
CHUNKFUN is the function to use to allocate chunks,
and FREEFUN the function to free them.
Return nonzero if successful, calls obstack_alloc_failed_handler if
allocation fails. */
int
_marpa_obs_begin (struct obstack *h,
int size, int alignment,
void *(*chunkfun) (long),
void (*freefun) (void *))
{
register struct _obstack_chunk *chunk; /* points to new chunk */
if (alignment == 0)
alignment = DEFAULT_ALIGNMENT;
if (size == 0)
/* Default size is what GNU malloc can fit in a 4096-byte block. */
{
/* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
Use the values for range checking, because if range checking is off,
the extra bytes won't be missed terribly, but if range checking is on
and we used a larger request, a whole extra 4096 bytes would be
allocated.
These number are irrelevant to the new GNU malloc. I suspect it is
less sensitive to the size of the request. */
int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
+ 4 + DEFAULT_ROUNDING - 1)
& ~(DEFAULT_ROUNDING - 1));
size = 4096 - extra;
}
h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
h->chunk_size = size;
h->alignment_mask = alignment - 1;
h->use_extra_arg = 0;
chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
/* if (!chunk) (*obstack_alloc_failed_handler) (); */
h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
alignment - 1);
h->chunk_limit = chunk->limit
= (char *) chunk + h->chunk_size;
chunk->prev = 0;
/* The initial chunk now contains no empty object. */
h->maybe_empty_object = 0;
h->alloc_failed = 0;
return 1;
}
int
_marpa_obs_begin_1 (struct obstack *h, int size, int alignment,
void *(*chunkfun) (void *, long),
void (*freefun) (void *, void *),
void *arg)
{
register struct _obstack_chunk *chunk; /* points to new chunk */
if (alignment == 0)
alignment = DEFAULT_ALIGNMENT;
if (size == 0)
/* Default size is what GNU malloc can fit in a 4096-byte block. */
{
/* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
Use the values for range checking, because if range checking is off,
the extra bytes won't be missed terribly, but if range checking is on
and we used a larger request, a whole extra 4096 bytes would be
allocated.
These number are irrelevant to the new GNU malloc. I suspect it is
less sensitive to the size of the request. */
int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
+ 4 + DEFAULT_ROUNDING - 1)
& ~(DEFAULT_ROUNDING - 1));
size = 4096 - extra;
}
h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
h->chunk_size = size;
h->alignment_mask = alignment - 1;
h->extra_arg = arg;
h->use_extra_arg = 1;
chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
/* if (!chunk) (*obstack_alloc_failed_handler) (); */
h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
alignment - 1);
h->chunk_limit = chunk->limit
= (char *) chunk + h->chunk_size;
chunk->prev = 0;
/* The initial chunk now contains no empty object. */
h->maybe_empty_object = 0;
h->alloc_failed = 0;
return 1;
}
/* Allocate a new current chunk for the obstack *H
on the assumption that LENGTH bytes need to be added
to the current object, or a new object of length LENGTH allocated.
Copies any partial object from the end of the old chunk
to the beginning of the new one. */
void
_marpa_obs_newchunk (struct obstack *h, int length)
{
register struct _obstack_chunk *old_chunk = h->chunk;
register struct _obstack_chunk *new_chunk;
register long new_size;
register long obj_size = h->next_free - h->object_base;
register long i;
long already;
char *object_base;
/* Compute size for new chunk. */
new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
if (new_size < h->chunk_size)
new_size = h->chunk_size;
/* Allocate and initialize the new chunk. */
new_chunk = CALL_CHUNKFUN (h, new_size);
/* if (!new_chunk) (*obstack_alloc_failed_handler) (); */
h->chunk = new_chunk;
new_chunk->prev = old_chunk;
new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
/* Compute an aligned object_base in the new chunk */
object_base =
__PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask);
/* Move the existing object to the new chunk.
Word at a time is fast and is safe if the object
is sufficiently aligned. */
if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
{
for (i = obj_size / sizeof (COPYING_UNIT) - 1;
i >= 0; i--)
((COPYING_UNIT *)object_base)[i]
= ((COPYING_UNIT *)h->object_base)[i];
/* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
but that can cross a page boundary on a machine
which does not do strict alignment for COPYING_UNITS. */
already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
}
else
already = 0;
/* Copy remaining bytes one by one. */
for (i = already; i < obj_size; i++)
object_base[i] = h->object_base[i];
/* If the object just copied was the only data in OLD_CHUNK,
free that chunk and remove it from the chain.
But not if that chunk might contain an empty object. */
if (! h->maybe_empty_object
&& (h->object_base
== __PTR_ALIGN ((char *) old_chunk, old_chunk->contents,
h->alignment_mask)))
{
new_chunk->prev = old_chunk->prev;
CALL_FREEFUN (h, old_chunk);
}
h->object_base = object_base;
h->next_free = h->object_base + obj_size;
/* The new chunk certainly contains no empty object yet. */
h->maybe_empty_object = 0;
}
/* Return nonzero if object OBJ has been allocated from obstack H.
This is here for debugging.
If you use it in a program, you are probably losing. */
/* Suppress -Wmissing-prototypes warning. We don't want to declare this in
obstack.h because it is just for debugging. */
int marpa_obs_allocated_p (struct obstack *h, void *obj);
int
marpa_obs_allocated_p (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 >= rather than > since the object cannot be exactly at
the beginning of the chunk but might be an empty object exactly
at the end of an adjacent chunk. */
while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
{
plp = lp->prev;
lp = plp;
}
return lp != 0;
}
/* The function name is overriden by a define, which we must
* in order to actually define the function.
*/
#undef marpa_obs_free
/* Free objects in obstack H, including OBJ and everything allocate
more recently than OBJ. If OBJ is zero, free everything in H. */
void
marpa_obs_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 ();
}
int
_marpa_obs_memory_used (struct obstack *h)
{
register struct _obstack_chunk* lp;
register int nbytes = 0;
for (lp = h->chunk; lp != 0; lp = lp->prev)
{
nbytes += lp->limit - (char *) lp;
}
return nbytes;
}