Imported Upstream version 4.1cupstream/4.1cupstream

1 files changed, 240 insertions, 0 deletions

diff --git a/lib/xmalloc.c b/lib/xmalloc.c
new file mode 100644
index 0000000..fe84a0b
--- /dev/null
+++ b/lib/xmalloc.c
@@ -0,0 +1,240 @@
+/* xmalloc.c -- malloc with out of memory checking
+
+   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+   1999, 2000, 2002, 2003, 2004, 2005, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include "xalloc.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+/* 1 if calloc is known to be compatible with GNU calloc.  This
+   matters if we are not also using the calloc module, which defines
+   HAVE_CALLOC and supports the GNU API even on non-GNU platforms.  */
+#if defined HAVE_CALLOC || defined __GLIBC__
+enum { HAVE_GNU_CALLOC = 1 };
+#else
+enum { HAVE_GNU_CALLOC = 0 };
+#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.  But omit overflow and size-zero tests if
+     HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
+     returns NULL if successful.  */
+  if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
+      || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
+    xalloc_die ();
+  return p;
+}
+
+/* Clone an object P of size S, with error checking.  There's no need
+   for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
+   need for an arithmetic overflow check.  */
+
+void *
+xmemdup (void const *p, size_t s)
+{
+  return memcpy (xmalloc (s), p, s);
+}
+
+/* Clone STRING.  */
+
+char *
+xstrdup (char const *string)
+{
+  return xmemdup (string, strlen (string) + 1);
+}