X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxalloc.h;h=987791bf2a88ec71dedc67550e72944f7be7897c;hb=1a9afb04e6f2fb36d17b3837942165cd1a0c50ac;hp=6881ea678d2cb833dc0a5f4a845423ab66346a68;hpb=7c6d5072278ec9af612e21f0507a009ed37816e1;p=gnulib.git
diff --git a/lib/xalloc.h b/lib/xalloc.h
index 6881ea678..987791bf2 100644
--- a/lib/xalloc.h
+++ b/lib/xalloc.h
@@ -1,12 +1,11 @@
/* xalloc.h -- malloc with out-of-memory checking
- Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 1990-2000, 2003-2004, 2006-2011 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
@@ -14,28 +13,30 @@
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 . */
#ifndef XALLOC_H_
# define XALLOC_H_
# include
+# 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.
@@ -43,33 +44,21 @@ extern "C" {
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 *xnmalloc (size_t n, size_t s);
-void *xzalloc (size_t s);
-void *xcalloc (size_t n, size_t s);
-void *xrealloc (void *p, size_t s);
-void *xnrealloc (void *p, size_t n, 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 *x2nrealloc (void *p, size_t *pn, size_t s);
-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
@@ -77,53 +66,168 @@ char *xstrdup (char const *str);
it first and use the typedef name. */
/* Allocate an object of type T dynamically, with error checking. */
-/* extern T *XMALLOC (typename T); */
-#define XMALLOC(T) \
- ((T *) xmalloc (sizeof (T)))
-
-/* Allocate memory for NMEMB elements of type T, with error checking. */
-/* extern T *XNMALLOC (size_t nmemb, typename T); */
-#if HAVE_INLINE
-/* xnmalloc performs a division and multiplication by sizeof (T). Arrange to
- perform the division at compile-time and the multiplication with a factor
- known at compile-time. */
-# define XNMALLOC(N,T) \
- ((T *) (sizeof (T) == 1 \
- ? xmalloc (N) \
- : xnboundedmalloc(N, (size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / sizeof (T), sizeof (T))))
-static inline void *
-xnboundedmalloc (size_t n, size_t bound, size_t s)
+/* extern t *XMALLOC (typename t); */
+# define XMALLOC(t) ((t *) xmalloc (sizeof (t)))
+
+/* Allocate memory for N elements of type T, with error checking. */
+/* extern t *XNMALLOC (size_t n, typename t); */
+# define XNMALLOC(n, t) \
+ ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t))))
+
+/* Allocate an object of type T dynamically, with error checking,
+ and zero it. */
+/* extern t *XZALLOC (typename t); */
+# define XZALLOC(t) ((t *) xzalloc (sizeof (t)))
+
+/* Allocate memory for N elements of type T, with error checking,
+ and zero it. */
+/* extern t *XCALLOC (size_t n, typename t); */
+# define XCALLOC(n, t) \
+ ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t))))
+
+
+# if HAVE_INLINE
+# define static_inline static inline
+# else
+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)
{
- if (n > bound)
+ if (xalloc_oversized (n, s))
xalloc_die ();
return xmalloc (n * s);
}
-#else
-# define XNMALLOC(N,T) \
- ((T *) (sizeof (T) == 1 ? xmalloc (N) : xnmalloc (N, sizeof (T))))
-#endif
-/* Allocate an object of type T dynamically, with error checking,
- and zero it. */
-/* extern T *XZALLOC (typename T); */
-#define XZALLOC(T) \
- ((T *) xzalloc (sizeof (T)))
+/* 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. */
-/* Allocate memory for NMEMB elements of type T, with error checking,
- and zero it. */
-/* extern T *XCALLOC (size_t nmemb, typename T); */
-#define XCALLOC(N,T) \
- ((T *) xcalloc (N, sizeof (T)))
+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)
+{
+ if (xalloc_oversized (n, s))
+ xalloc_die ();
+ return xrealloc (p, n * s);
+}
+
+/* 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 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:
+
+ 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 (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. 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
+ {
+ /* 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 xrealloc (p, n * s);
+}
/* Return a pointer to a new buffer of N bytes. This is like xmalloc,
- except it returns char *.
- xcharalloc (N) is equivalent to XNMALLOC (N, char). */
-static inline char *
+ 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)
{
- return (char *) xmalloc (n);
+ return XNMALLOC (n, char);
}
+# endif
+
# ifdef __cplusplus
}