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/* xmalloc.c -- malloc with out of memory checking |
/* xmalloc.c -- malloc with out of memory checking |
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Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2003, |
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1999, 2000, 2002, 2003 Free Software Foundation, Inc. |
1999, 2000, 2002, 2003 Free Software Foundation, Inc. |
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This program is free software; you can redistribute it and/or modify |
This program is free software; you can redistribute it and/or modify |
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#include "xalloc.h" |
#include "xalloc.h" |
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#include <stdlib.h> |
#include <stdlib.h> |
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#include <string.h> |
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#include "gettext.h" |
#include "gettext.h" |
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#define _(msgid) gettext (msgid) |
#define _(msgid) gettext (msgid) |
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#define N_(msgid) msgid |
#define N_(msgid) msgid |
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#include "error.h" |
#include "error.h" |
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#include "exit.h" |
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#include "exitfail.h" |
#include "exitfail.h" |
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/* The following tests require AC_PREREQ(2.54). */ |
#ifndef SIZE_MAX |
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# define SIZE_MAX ((size_t) -1) |
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#endif |
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#ifndef HAVE_MALLOC |
#ifndef HAVE_MALLOC |
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"you must run the autoconf test for a GNU libc compatible malloc" |
"you must run the autoconf test for a GNU libc compatible malloc" |
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error (exit_failure, 0, "%s", _(xalloc_msg_memory_exhausted)); |
error (exit_failure, 0, "%s", _(xalloc_msg_memory_exhausted)); |
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/* The `noreturn' cannot be given to error, since it may return if |
/* The `noreturn' cannot be given to error, since it may return if |
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its first argument is 0. To help compilers understand the |
its first argument is 0. To help compilers understand the |
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xalloc_die does terminate, call exit. */ |
xalloc_die does terminate, call abort. */ |
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exit (EXIT_FAILURE); |
abort (); |
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} |
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/* Allocate an array of N objects, each with S bytes of memory, |
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dynamically, with error checking. S must be nonzero. */ |
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static inline void * |
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xnmalloc_inline (size_t n, size_t s) |
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{ |
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void *p; |
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if (xalloc_oversized (n, s) || ! (p = malloc (n * s))) |
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xalloc_die (); |
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return p; |
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} |
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void * |
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xnmalloc (size_t n, size_t s) |
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{ |
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return xnmalloc_inline (n, s); |
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} |
} |
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/* Allocate N bytes of memory dynamically, with error checking. */ |
/* Allocate N bytes of memory dynamically, with error checking. */ |
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void * |
void * |
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xmalloc (size_t n) |
xmalloc (size_t n) |
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{ |
{ |
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void *p; |
return xnmalloc_inline (n, 1); |
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} |
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/* Change the size of an allocated block of memory P to an array of N |
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objects each of S bytes, with error checking. S must be nonzero. */ |
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p = malloc (n); |
static inline void * |
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if (p == 0) |
xnrealloc_inline (void *p, size_t n, size_t s) |
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{ |
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if (xalloc_oversized (n, s) || ! (p = realloc (p, n * s))) |
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xalloc_die (); |
xalloc_die (); |
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return p; |
return p; |
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} |
} |
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void * |
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xnrealloc (void *p, size_t n, size_t s) |
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{ |
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return xnrealloc_inline (p, n, s); |
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} |
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/* Change the size of an allocated block of memory P to N bytes, |
/* Change the size of an allocated block of memory P to N bytes, |
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with error checking. */ |
with error checking. */ |
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void * |
void * |
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xrealloc (void *p, size_t n) |
xrealloc (void *p, size_t n) |
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{ |
{ |
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p = realloc (p, n); |
return xnrealloc_inline (p, n, 1); |
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if (p == 0) |
} |
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xalloc_die (); |
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return p; |
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/* If P is null, allocate a block of at least *PN such objects; |
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otherwise, reallocate P so that it contains more than *PN objects |
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each of S bytes. *PN must be nonzero unless P is null, and S must |
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be nonzero. Set *PN to the new number of objects, and return the |
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pointer to the new block. *PN is never set to zero, and the |
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returned pointer is never null. |
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Repeated reallocations are guaranteed to make progress, either by |
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allocating an initial block with a nonzero size, or by allocating a |
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larger block. |
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In the following implementation, nonzero sizes are doubled so that |
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repeated reallocations have O(N log N) overall cost rather than |
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O(N**2) cost, but the specification for this function does not |
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guarantee that sizes are doubled. |
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Here is an example of use: |
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int *p = NULL; |
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size used = 0; |
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size allocated = 0; |
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void |
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append_int (int value) |
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{ |
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if (used == allocated) |
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p = x2nrealloc (p, &allocated, sizeof *p); |
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p[used++] = value; |
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} |
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This causes x2nrealloc to allocate a block of some nonzero size the |
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first time it is called. |
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To have finer-grained control over the initial size, set *PN to a |
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nonzero value before calling this function with P == NULL. For |
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example: |
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int *p = NULL; |
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size used = 0; |
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size allocated = 0; |
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size allocated1 = 1000; |
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void |
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append_int (int value) |
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{ |
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if (used == allocated) |
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{ |
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p = x2nrealloc (p, &allocated1, sizeof *p); |
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allocated = allocated1; |
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} |
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p[used++] = value; |
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} |
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*/ |
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static inline void * |
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x2nrealloc_inline (void *p, size_t *pn, size_t s) |
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{ |
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size_t n = *pn; |
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if (! p) |
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{ |
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if (! n) |
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{ |
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/* The approximate size to use for initial small allocation |
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requests, when the invoking code specifies an old size of |
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zero. 64 bytes is the largest "small" request for the |
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GNU C library malloc. */ |
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enum { DEFAULT_MXFAST = 64 }; |
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n = DEFAULT_MXFAST / s; |
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n += !n; |
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} |
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} |
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else |
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{ |
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if (SIZE_MAX / 2 / s < n) |
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xalloc_die (); |
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n *= 2; |
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} |
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*pn = n; |
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return xrealloc (p, n * s); |
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} |
} |
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/* Allocate memory for N elements of S bytes, with error checking. */ |
void * |
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x2nrealloc (void *p, size_t *pn, size_t s) |
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{ |
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return x2nrealloc_inline (p, pn, s); |
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} |
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/* If P is null, allocate a block of at least *PN bytes; otherwise, |
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reallocate P so that it contains more than *PN bytes. *PN must be |
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nonzero unless P is null. Set *PN to the new block's size, and |
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return the pointer to the new block. *PN is never set to zero, and |
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the returned pointer is never null. */ |
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void * |
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x2realloc (void *p, size_t *pn) |
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{ |
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return x2nrealloc_inline (p, pn, 1); |
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} |
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/* Allocate S bytes of zeroed memory dynamically, with error checking. |
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There's no need for xnzalloc (N, S), since it would be equivalent |
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to xcalloc (N, S). */ |
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void * |
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xzalloc (size_t s) |
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{ |
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return memset (xmalloc (s), 0, s); |
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} |
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/* Allocate zeroed memory for N elements of S bytes, with error |
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checking. S must be nonzero. */ |
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void * |
void * |
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xcalloc (size_t n, size_t s) |
xcalloc (size_t n, size_t s) |
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{ |
{ |
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void *p; |
void *p; |
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/* Test for overflow, since some calloc implementations don't have |
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p = calloc (n, s); |
proper overflow checks. */ |
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if (p == 0) |
if (xalloc_oversized (n, s) || ! (p = calloc (n, s))) |
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xalloc_die (); |
xalloc_die (); |
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return p; |
return p; |
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} |
} |
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/* Clone an object P of size S, with error checking. There's no need |
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for xnclone (P, N, S), since xclone (P, N * S) works without any |
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need for an arithmetic overflow check. */ |
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void * |
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xclone (void const *p, size_t s) |
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{ |
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return memcpy (xmalloc (s), p, s); |
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} |