X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxalloc.h;h=5f891457ba7476f5094cff1516d8093ff3a227d4;hb=1276a2c5f24c0c932426aca9c899fa524d2443f2;hp=9c397aa752bfbd541ce801c5b4e7c8084c6276bc;hpb=08262434df55b5f3c509d2afacb1a39d36e340c4;p=gnulib.git

diff --git a/lib/xalloc.h b/lib/xalloc.h
index 9c397aa75..5f891457b 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, 2006-2014 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
@@ -14,72 +13,214 @@
    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_
+#define XALLOC_H_
 
-# include <stddef.h>
+#include <stddef.h>
 
+#include "xalloc-oversized.h"
 
-# ifdef __cplusplus
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
+_GL_INLINE_HEADER_BEGIN
+#ifndef XALLOC_INLINE
+# define XALLOC_INLINE _GL_INLINE
+#endif
+
+#ifdef __cplusplus
 extern "C" {
-# endif
+#endif
 
 
-# ifndef __attribute__
-#  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
-#   define __attribute__(x)
-#  endif
-# endif
+#if __GNUC__ >= 3
+# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+#else
+# define _GL_ATTRIBUTE_MALLOC
+#endif
 
-# ifndef ATTRIBUTE_NORETURN
-#  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
-# endif
+#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.
    It must be defined by the application, either explicitly
    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))
-
-/* Return a pointer to a new buffer of S bytes.  This is like xmalloc,
+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
+   following macros to a function pointer or array type, you need to typedef
+   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 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))))
+
+
+/* Allocate an array of N objects, each with S bytes of memory,
+   dynamically, with error checking.  S must be nonzero.  */
+
+XALLOC_INLINE void *xnmalloc (size_t n, size_t s)
+                    _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
+XALLOC_INLINE void *
+xnmalloc (size_t n, size_t s)
+{
+  if (xalloc_oversized (n, s))
+    xalloc_die ();
+  return xmalloc (n * 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.  */
+
+XALLOC_INLINE void *xnrealloc (void *p, size_t n, size_t s)
+                    _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
+XALLOC_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;
+       }
+
+   */
+
+XALLOC_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 *.  */
-static inline char *
-xcharalloc (size_t s)
+
+XALLOC_INLINE char *xcharalloc (size_t n)
+                    _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
+XALLOC_INLINE char *
+xcharalloc (size_t n)
 {
-  return (char *) xmalloc (s);
+  return XNMALLOC (n, char);
 }
 
-# ifdef __cplusplus
+#ifdef __cplusplus
 }
 
 /* C++ does not allow conversions from void * to other pointer types
@@ -116,7 +257,7 @@ xmemdup (T const *p, size_t s)
   return (T *) xmemdup ((void const *) p, s);
 }
 
-# endif
+#endif
 
 
 #endif /* !XALLOC_H_ */