/* xalloc.h -- malloc with out-of-memory checking
- Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2003, 2004, 2006 Free Software Foundation, Inc.
+ Copyright (C) 1990-2000, 2003-2004, 2006-2012 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ 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.
+ the Free Software Foundation; either version 3 of the License, 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
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. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef XALLOC_H_
# define XALLOC_H_
# include <stddef.h>
+# include "xalloc-oversized.h"
# ifdef __cplusplus
extern "C" {
# endif
-# ifndef __attribute__
-# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
-# define __attribute__(x)
-# endif
+# if __GNUC__ >= 3
+# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+# else
+# define _GL_ATTRIBUTE_MALLOC
# endif
-# ifndef ATTRIBUTE_NORETURN
-# define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
+# if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
+# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
+# else
+# define _GL_ATTRIBUTE_ALLOC_SIZE(args)
# endif
/* This function is always triggered when memory is exhausted.
or by using gnulib's xalloc-die module. This is the
function to call when one wants the program to die because of a
memory allocation failure. */
-extern void xalloc_die (void) ATTRIBUTE_NORETURN;
-
-void *xmalloc (size_t s);
-void *xzalloc (size_t s);
-void *xcalloc (size_t n, size_t s);
-void *xrealloc (void *p, size_t s);
+extern _Noreturn void xalloc_die (void);
+
+void *xmalloc (size_t s)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
+void *xzalloc (size_t s)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
+void *xcalloc (size_t n, size_t s)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
+void *xrealloc (void *p, size_t s)
+ _GL_ATTRIBUTE_ALLOC_SIZE ((2));
void *x2realloc (void *p, size_t *pn);
-void *xmemdup (void const *p, size_t s);
-char *xstrdup (char const *str);
-
-/* Return 1 if an array of N objects, each of size S, cannot exist due
- to size arithmetic overflow. S must be positive and N must be
- nonnegative. This is a macro, not an inline function, so that it
- works correctly even when SIZE_MAX < N.
-
- By gnulib convention, SIZE_MAX represents overflow in size
- calculations, so the conservative dividend to use here is
- SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
- However, malloc (SIZE_MAX) fails on all known hosts where
- sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
- exactly-SIZE_MAX allocations on such hosts; this avoids a test and
- branch when S is known to be 1. */
-# define xalloc_oversized(n, s) \
- ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
-
+void *xmemdup (void const *p, size_t s)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((2));
+char *xstrdup (char const *str)
+ _GL_ATTRIBUTE_MALLOC;
/* In the following macros, T must be an elementary or structure/union or
typedef'ed type, or a pointer to such a type. To apply one of the
# if HAVE_INLINE
# define static_inline static inline
# else
- void *xnmalloc (size_t n, size_t s);
- void *xnrealloc (void *p, size_t n, size_t s);
- void *x2nrealloc (void *p, size_t *pn, size_t s);
- char *xcharalloc (size_t n);
+void *xnmalloc (size_t n, size_t s)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
+void *xnrealloc (void *p, size_t n, size_t s)
+ _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
+void *x2nrealloc (void *p, size_t *pn, size_t s);
+char *xcharalloc (size_t n)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
# endif
# ifdef static_inline
/* Allocate an array of N objects, each with S bytes of memory,
dynamically, with error checking. S must be nonzero. */
+static_inline void *xnmalloc (size_t n, size_t s)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
static_inline void *
xnmalloc (size_t n, size_t s)
{
/* 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 (void *p, size_t n, size_t s)
+ _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
static_inline void *
xnrealloc (void *p, size_t n, size_t s)
{
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.
+ In the following implementation, nonzero sizes are increased by a
+ factor of approximately 1.5 so that repeated reallocations have
+ O(N) overall cost rather than O(N**2) cost, but the
+ specification for this function does not guarantee that rate.
Here is an example of use:
void
append_int (int value)
{
- if (used == allocated)
- p = x2nrealloc (p, &allocated, sizeof *p);
- p[used++] = 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
void
append_int (int value)
{
- if (used == allocated)
- {
- p = x2nrealloc (p, &allocated1, sizeof *p);
- allocated = allocated1;
- }
- p[used++] = value;
+ if (used == allocated)
+ {
+ p = x2nrealloc (p, &allocated1, sizeof *p);
+ allocated = allocated1;
+ }
+ p[used++] = value;
}
*/
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;
- }
+ {
+ /* The approximate size to use for initial small allocation
+ requests, when the invoking code specifies an old size of
+ zero. This is the largest "small" request for the GNU C
+ library malloc. */
+ enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
+
+ n = DEFAULT_MXFAST / s;
+ n += !n;
+ }
}
else
{
- if (((size_t) -1) / 2 / s < n)
- xalloc_die ();
- n *= 2;
+ /* Set N = ceil (1.5 * N) so that progress is made if N == 1.
+ Check for overflow, so that N * S stays in size_t range.
+ The check is slightly conservative, but an exact check isn't
+ worth the trouble. */
+ if ((size_t) -1 / 3 * 2 / s <= n)
+ xalloc_die ();
+ n += (n + 1) / 2;
}
*pn = n;
/* Return a pointer to a new buffer of N bytes. This is like xmalloc,
except it returns char *. */
+static_inline char *xcharalloc (size_t n)
+ _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
static_inline char *
xcharalloc (size_t n)
{
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