/* xalloc.h -- malloc with out-of-memory checking

   Copyright (C) 1990-2000, 2003-2004, 2006-2017 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 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

   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, see <http://www.gnu.org/licenses/>.  */

#ifndef XALLOC_H_

#define XALLOC_H_

#include <stddef.h>

#include <stdint.h>

#include "xalloc-oversized.h"

#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

#if __GNUC__ >= 3

# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))

#else

# define _GL_ATTRIBUTE_MALLOC

#endif

#if ! defined __clang__ && \

    (__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 _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)

      _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.  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;

        }

      if (xalloc_oversized (n, s))

        xalloc_die ();

    }

  else

    {

      /* Set N = floor (1.5 * N) + 1 so that progress is made even if N == 0.

         Check for overflow, so that N * S stays in both ptrdiff_t and

         size_t range.  The check may be slightly conservative, but an

         exact check isn't worth the trouble.  */

      if ((PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : SIZE_MAX) / 3 * 2 / s

          <= n)

        xalloc_die ();

      n += n / 2 + 1;

    }

  *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 *.  */

XALLOC_INLINE char *xcharalloc (size_t n)

                    _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));

XALLOC_INLINE char *

xcharalloc (size_t n)

{

  return XNMALLOC (n, char);

}

#ifdef __cplusplus

}

/* C++ does not allow conversions from void * to other pointer types

   without a cast.  Use templates to work around the problem when

   possible.  */

template <typename T> inline T *

xrealloc (T *p, size_t s)

{

  return (T *) xrealloc ((void *) p, s);

}

template <typename T> inline T *

xnrealloc (T *p, size_t n, size_t s)

{

  return (T *) xnrealloc ((void *) p, n, s);

}

template <typename T> inline T *

x2realloc (T *p, size_t *pn)

{

  return (T *) x2realloc ((void *) p, pn);

}

template <typename T> inline T *

x2nrealloc (T *p, size_t *pn, size_t s)

{

  return (T *) x2nrealloc ((void *) p, pn, s);

}

template <typename T> inline T *

xmemdup (T const *p, size_t s)

{

  return (T *) xmemdup ((void const *) p, s);

}

#endif

_GL_INLINE_HEADER_END

#endif /* !XALLOC_H_ */