19990502 sourceware importbinu_ss_19990502

1 files changed, 116 insertions, 0 deletions

diff --git a/include/objalloc.h b/include/objalloc.h
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+++ b/include/objalloc.h
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+/* objalloc.h -- routines to allocate memory for objects
+   Copyright 1997 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Cygnus Solutions.
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#ifndef OBJALLOC_H
+#define OBJALLOC_H
+
+#include "ansidecl.h"
+
+/* These routines allocate space for an object.  The assumption is
+   that the object will want to allocate space as it goes along, but
+   will never want to free any particular block.  There is a function
+   to free a block, which also frees all more recently allocated
+   blocks.  There is also a function to free all the allocated space.
+
+   This is essentially a specialization of obstacks.  The main
+   difference is that a block may not be allocated a bit at a time.
+   Another difference is that these routines are always built on top
+   of malloc, and always pass an malloc failure back to the caller,
+   unlike more recent versions of obstacks.  */
+
+/* This is what an objalloc structure looks like.  Callers should not
+   refer to these fields, nor should they allocate these structure
+   themselves.  Instead, they should only create them via
+   objalloc_init, and only access them via the functions and macros
+   listed below.  The structure is only defined here so that we can
+   access it via macros.  */
+
+struct objalloc
+{
+  char *current_ptr;
+  unsigned int current_space;
+  PTR chunks;
+};
+
+/* Work out the required alignment.  */
+
+struct objalloc_align { char x; double d; };
+
+#if defined (__STDC__) && __STDC__
+#ifndef offsetof
+#include <stddef.h>
+#endif
+#define OBJALLOC_ALIGN \
+  ((ptrdiff_t) ((char *) &((struct objalloc_align *) 0)->d - (char *) 0))
+#else
+#define OBJALLOC_ALIGN \
+  ((long) ((char *) &((struct objalloc_align *) 0)->d - (char *) 0))
+#endif
+
+/* Create an objalloc structure.  Returns NULL if malloc fails.  */
+
+extern struct objalloc *objalloc_create PARAMS ((void));
+
+/* Allocate space from an objalloc structure.  Returns NULL if malloc
+   fails.  */
+
+extern PTR _objalloc_alloc PARAMS ((struct objalloc *, unsigned long));
+
+/* The macro version of objalloc_alloc.  We only define this if using
+   gcc, because otherwise we would have to evaluate the arguments
+   multiple times, or use a temporary field as obstack.h does.  */
+
+#if defined (__GNUC__) && defined (__STDC__) && __STDC__
+
+/* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and
+   does not implement __extension__.  But that compiler doesn't define
+   __GNUC_MINOR__.  */
+#if __GNUC__ < 2 || (__NeXT__ && !__GNUC_MINOR__)
+#define __extension__
+#endif
+
+#define objalloc_alloc(o, l)						\
+  __extension__								\
+  ({ struct objalloc *__o = (o);					\
+     unsigned long __len = (l);						\
+     if (__len == 0)							\
+       __len = 1;							\
+     __len = (__len + OBJALLOC_ALIGN - 1) &~ (OBJALLOC_ALIGN - 1);	\
+     (__len <= __o->current_space					\
+      ? (__o->current_ptr += __len,					\
+	 __o->current_space -= __len,					\
+	 (PTR) (__o->current_ptr - __len))				\
+      : _objalloc_alloc (__o, __len)); })
+
+#else /* ! __GNUC__ */
+
+#define objalloc_alloc(o, l) _objalloc_alloc ((o), (l))
+
+#endif /* ! __GNUC__ */
+
+/* Free an entire objalloc structure.  */
+
+extern void objalloc_free PARAMS ((struct objalloc *));
+
+/* Free a block allocated by objalloc_alloc.  This also frees all more
+   recently allocated blocks.  */
+
+extern void objalloc_free_block PARAMS ((struct objalloc *, PTR));
+
+#endif /* OBJALLOC_H */