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Diffstat (limited to 'src/gl/xalloc.h')
| -rw-r--r-- | src/gl/xalloc.h | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/src/gl/xalloc.h b/src/gl/xalloc.h new file mode 100644 index 0000000..6cd7a68 --- /dev/null +++ b/src/gl/xalloc.h @@ -0,0 +1,275 @@ +/* xalloc.h -- malloc with out-of-memory checking + + Copyright (C) 1990-2000, 2003-2004, 2006-2021 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/>. */ + +#ifndef XALLOC_H_ +#define XALLOC_H_ + +#include <stddef.h> +#include <stdint.h> + +#if GNULIB_XALLOC +# include "idx.h" +# include "intprops.h" +#endif + +#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 GNULIB_XALLOC_DIE + +/* 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); + +#endif /* GNULIB_XALLOC_DIE */ + +#if GNULIB_XALLOC + +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 *xreallocarray (void *p, size_t n, size_t s) + _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3)); +void *x2realloc (void *p, size_t *pn); +void *xpalloc (void *pa, idx_t *nitems, idx_t nitems_incr_min, + ptrdiff_t nitems_max, idx_t item_size); +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) +{ + return xreallocarray (NULL, n, s); +} + +/* FIXME: Deprecate this in favor of xreallocarray? */ +/* 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) +{ + return xreallocarray (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; + } + } + else + { + /* Set N = floor (1.5 * N) + 1 to make progress even if N == 0. */ + if (INT_ADD_WRAPV (n, (n >> 1) + 1, &n)) + xalloc_die (); + } + + p = xreallocarray (p, n, s); + *pn = n; + return p; +} + +/* 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); +} + +#endif /* GNULIB_XALLOC */ + + +#ifdef __cplusplus +} +#endif + + +#if GNULIB_XALLOC && defined __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 * +xreallocarray (T *p, size_t n, size_t s) +{ + return (T *) xreallocarray ((void *) p, n, s); +} + +/* FIXME: Deprecate this in favor of xreallocarray? */ +template <typename T> inline T * +xnrealloc (T *p, size_t n, size_t s) +{ + return xreallocarray (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 /* GNULIB_XALLOC && C++ */ + + +_GL_INLINE_HEADER_END + +#endif /* !XALLOC_H_ */ |