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Diffstat (limited to 'src/gl/xmalloc.c')
| -rw-r--r-- | src/gl/xmalloc.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/gl/xmalloc.c b/src/gl/xmalloc.c new file mode 100644 index 0000000..88698fa --- /dev/null +++ b/src/gl/xmalloc.c @@ -0,0 +1,184 @@ +/* xmalloc.c -- malloc with out of memory checking + + Copyright (C) 1990-2000, 2002-2006, 2008-2021 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 <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +#define XALLOC_INLINE _GL_EXTERN_INLINE + +#include "xalloc.h" + +#include "intprops.h" +#include "minmax.h" + +#include <stdlib.h> +#include <string.h> + +/* Allocate N bytes of memory dynamically, with error checking. */ + +void * +xmalloc (size_t n) +{ + void *p = malloc (n); + if (!p) + xalloc_die (); + return p; +} + +/* Change the size of an allocated block of memory P to N bytes, + with error checking. */ + +void * +xrealloc (void *p, size_t n) +{ + void *r = realloc (p, n); + if (!r && (!p || n)) + xalloc_die (); + return r; +} + +/* Change the size of an allocated block of memory P to an array of N + objects each of S bytes, with error checking. */ + +void * +xreallocarray (void *p, size_t n, size_t s) +{ + void *r = reallocarray (p, n, s); + if (!r && (!p || (n && s))) + xalloc_die (); + return r; +} + +/* If P is null, allocate a block of at least *PN bytes; otherwise, + reallocate P so that it contains more than *PN bytes. *PN must be + nonzero unless P is null. Set *PN to the new block's size, and + return the pointer to the new block. *PN is never set to zero, and + the returned pointer is never null. */ + +void * +x2realloc (void *p, size_t *pn) +{ + return x2nrealloc (p, pn, 1); +} + +/* Grow PA, which points to an array of *NITEMS items, and return the + location of the reallocated array, updating *NITEMS to reflect its + new size. The new array will contain at least NITEMS_INCR_MIN more + items, but will not contain more than NITEMS_MAX items total. + ITEM_SIZE is the size of each item, in bytes. + + ITEM_SIZE and NITEMS_INCR_MIN must be positive. *NITEMS must be + nonnegative. If NITEMS_MAX is -1, it is treated as if it were + infinity. + + If PA is null, then allocate a new array instead of reallocating + the old one. + + Thus, to grow an array A without saving its old contents, do + { free (A); A = xpalloc (NULL, &AITEMS, ...); }. */ + +void * +xpalloc (void *pa, idx_t *nitems, idx_t nitems_incr_min, + ptrdiff_t nitems_max, idx_t item_size) +{ + idx_t n0 = *nitems; + + /* The approximate size to use for initial small allocation + requests. This is the largest "small" request for the GNU C + library malloc. */ + enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 }; + + /* If the array is tiny, grow it to about (but no greater than) + DEFAULT_MXFAST bytes. Otherwise, grow it by about 50%. + Adjust the growth according to three constraints: NITEMS_INCR_MIN, + NITEMS_MAX, and what the C language can represent safely. */ + + idx_t n; + if (INT_ADD_WRAPV (n0, n0 >> 1, &n)) + n = IDX_MAX; + if (0 <= nitems_max && nitems_max < n) + n = nitems_max; + + /* NBYTES is of a type suitable for holding the count of bytes in an object. + This is typically idx_t, but it should be size_t on (theoretical?) + platforms where SIZE_MAX < IDX_MAX so xpalloc does not pass + values greater than SIZE_MAX to xrealloc. */ +#if IDX_MAX <= SIZE_MAX + idx_t nbytes; +#else + size_t nbytes; +#endif + idx_t adjusted_nbytes + = (INT_MULTIPLY_WRAPV (n, item_size, &nbytes) + ? MIN (IDX_MAX, SIZE_MAX) + : nbytes < DEFAULT_MXFAST ? DEFAULT_MXFAST : 0); + if (adjusted_nbytes) + { + n = adjusted_nbytes / item_size; + nbytes = adjusted_nbytes - adjusted_nbytes % item_size; + } + + if (! pa) + *nitems = 0; + if (n - n0 < nitems_incr_min + && (INT_ADD_WRAPV (n0, nitems_incr_min, &n) + || (0 <= nitems_max && nitems_max < n) + || INT_MULTIPLY_WRAPV (n, item_size, &nbytes))) + xalloc_die (); + pa = xrealloc (pa, nbytes); + *nitems = n; + return pa; +} + +/* Allocate N bytes of zeroed memory dynamically, with error checking. + There's no need for xnzalloc (N, S), since it would be equivalent + to xcalloc (N, S). */ + +void * +xzalloc (size_t n) +{ + return xcalloc (n, 1); +} + +/* Allocate zeroed memory for N elements of S bytes, with error + checking. S must be nonzero. */ + +void * +xcalloc (size_t n, size_t s) +{ + void *p = calloc (n, s); + if (!p) + xalloc_die (); + return p; +} + +/* Clone an object P of size S, with error checking. There's no need + for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any + need for an arithmetic overflow check. */ + +void * +xmemdup (void const *p, size_t s) +{ + return memcpy (xmalloc (s), p, s); +} + +/* Clone STRING. */ + +char * +xstrdup (char const *string) +{ + return xmemdup (string, strlen (string) + 1); +} |