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-rw-r--r--lib/xmalloc.c221
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diff --git a/lib/xmalloc.c b/lib/xmalloc.c
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+/* xmalloc.c -- malloc with out of memory checking
+
+ Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+ 1999, 2000, 2002, 2003, 2004 Free Software Foundation, Inc.
+
+ 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,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "xalloc.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+/* Allocate an array of N objects, each with S bytes of memory,
+ dynamically, with error checking. S must be nonzero. */
+
+static inline void *
+xnmalloc_inline (size_t n, size_t s)
+{
+ void *p;
+ if (xalloc_oversized (n, s) || (! (p = malloc (n * s)) && n != 0))
+ xalloc_die ();
+ return p;
+}
+
+void *
+xnmalloc (size_t n, size_t s)
+{
+ return xnmalloc_inline (n, s);
+}
+
+/* Allocate N bytes of memory dynamically, with error checking. */
+
+void *
+xmalloc (size_t n)
+{
+ return xnmalloc_inline (n, 1);
+}
+
+/* Change the size of an allocated block of memory P to an array of N
+ objects each of S bytes, with error checking. S must be nonzero. */
+
+static inline void *
+xnrealloc_inline (void *p, size_t n, size_t s)
+{
+ if (xalloc_oversized (n, s) || (! (p = realloc (p, n * s)) && n != 0))
+ xalloc_die ();
+ return p;
+}
+
+void *
+xnrealloc (void *p, size_t n, size_t s)
+{
+ return xnrealloc_inline (p, n, s);
+}
+
+/* Change the size of an allocated block of memory P to N bytes,
+ with error checking. */
+
+void *
+xrealloc (void *p, size_t n)
+{
+ return xnrealloc_inline (p, n, 1);
+}
+
+
+/* If P is null, allocate a block of at least *PN such objects;
+ otherwise, reallocate P so that it contains more than *PN objects
+ each of S bytes. *PN must be nonzero unless P is null, and S must
+ be nonzero. Set *PN to the new number of objects, and return the
+ pointer to the new block. *PN is never set to zero, and the
+ returned pointer is never null.
+
+ Repeated reallocations are guaranteed to make progress, either by
+ allocating an initial block with a nonzero size, or by allocating a
+ larger block.
+
+ In the following implementation, nonzero sizes are doubled so that
+ repeated reallocations have O(N log N) overall cost rather than
+ O(N**2) cost, but the specification for this function does not
+ guarantee that sizes are doubled.
+
+ Here is an example of use:
+
+ int *p = NULL;
+ size_t used = 0;
+ size_t allocated = 0;
+
+ void
+ append_int (int value)
+ {
+ if (used == allocated)
+ p = x2nrealloc (p, &allocated, sizeof *p);
+ p[used++] = value;
+ }
+
+ This causes x2nrealloc to allocate a block of some nonzero size the
+ first time it is called.
+
+ To have finer-grained control over the initial size, set *PN to a
+ nonzero value before calling this function with P == NULL. For
+ example:
+
+ int *p = NULL;
+ size_t used = 0;
+ size_t allocated = 0;
+ size_t allocated1 = 1000;
+
+ void
+ append_int (int value)
+ {
+ if (used == allocated)
+ {
+ p = x2nrealloc (p, &allocated1, sizeof *p);
+ allocated = allocated1;
+ }
+ p[used++] = value;
+ }
+
+ */
+
+static inline void *
+x2nrealloc_inline (void *p, size_t *pn, size_t s)
+{
+ size_t n = *pn;
+
+ if (! p)
+ {
+ if (! n)
+ {
+ /* The approximate size to use for initial small allocation
+ requests, when the invoking code specifies an old size of
+ zero. 64 bytes is the largest "small" request for the
+ GNU C library malloc. */
+ enum { DEFAULT_MXFAST = 64 };
+
+ n = DEFAULT_MXFAST / s;
+ n += !n;
+ }
+ }
+ else
+ {
+ if (SIZE_MAX / 2 / s < n)
+ xalloc_die ();
+ n *= 2;
+ }
+
+ *pn = n;
+ return xrealloc (p, n * s);
+}
+
+void *
+x2nrealloc (void *p, size_t *pn, size_t s)
+{
+ return x2nrealloc_inline (p, pn, s);
+}
+
+/* If P is null, allocate a block of at least *PN bytes; otherwise,
+ reallocate P so that it contains more than *PN bytes. *PN must be
+ nonzero unless P is null. Set *PN to the new block's size, and
+ return the pointer to the new block. *PN is never set to zero, and
+ the returned pointer is never null. */
+
+void *
+x2realloc (void *p, size_t *pn)
+{
+ return x2nrealloc_inline (p, pn, 1);
+}
+
+/* Allocate S bytes of zeroed memory dynamically, with error checking.
+ There's no need for xnzalloc (N, S), since it would be equivalent
+ to xcalloc (N, S). */
+
+void *
+xzalloc (size_t s)
+{
+ return memset (xmalloc (s), 0, s);
+}
+
+/* Allocate zeroed memory for N elements of S bytes, with error
+ checking. S must be nonzero. */
+
+void *
+xcalloc (size_t n, size_t s)
+{
+ void *p;
+ /* Test for overflow, since some calloc implementations don't have
+ proper overflow checks. */
+ if (xalloc_oversized (n, s) || (! (p = calloc (n, s)) && n != 0))
+ xalloc_die ();
+ return p;
+}
+
+/* Clone an object P of size S, with error checking. There's no need
+ for xnclone (P, N, S), since xclone (P, N * S) works without any
+ need for an arithmetic overflow check. */
+
+void *
+xclone (void const *p, size_t s)
+{
+ return memcpy (xmalloc (s), p, s);
+}