X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxalloc.h;h=6c9b53bf6fabbdc3c96f0e44a24b0bb778574250;hb=fa1db0dd22768f09a507674a30beb5b8a87bb35f;hp=fb5cdcab32d5ebd447a9cdcc3de74aaf0f11a3c0;hpb=9dd25cd0161c75210441a73709c93c7dcb087efa;p=gnulib.git diff --git a/lib/xalloc.h b/lib/xalloc.h index fb5cdcab3..6c9b53bf6 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, 2006, 2007 Free Software Foundation, Inc. + Copyright (C) 1990-2000, 2003-2004, 2006-2013 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 @@ -14,60 +13,60 @@ 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 . */ #ifndef XALLOC_H_ -# define XALLOC_H_ +#define XALLOC_H_ -# include +#include +#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 *xzalloc (size_t s); -void *xcalloc (size_t n, size_t s); -void *xrealloc (void *p, 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 *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)) - +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 @@ -76,40 +75,31 @@ char *xstrdup (char const *str); /* Allocate an object of type T dynamically, with error checking. */ /* extern t *XMALLOC (typename t); */ -# define XMALLOC(t) ((t *) xmalloc (sizeof (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)))) +#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))) +#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)))) - +#define XCALLOC(n, t) \ + ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t)))) -# if HAVE_INLINE -# define static_inline static inline -# else - void *xnmalloc (size_t n, size_t s); - void *xnrealloc (void *p, size_t n, size_t s); - void *x2nrealloc (void *p, size_t *pn, size_t s); - char *xcharalloc (size_t n); -# endif - -# ifdef static_inline /* Allocate an array of N objects, each with S bytes of memory, dynamically, with error checking. S must be nonzero. */ -static_inline void * +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)) @@ -120,7 +110,9 @@ xnmalloc (size_t n, size_t 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. */ -static_inline void * +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)) @@ -141,7 +133,7 @@ xnrealloc (void *p, size_t n, size_t s) In the following implementation, nonzero sizes are increased by a factor of approximately 1.5 so that repeated reallocations have - O(N log N) overall cost rather than O(N**2) cost, but the + 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: @@ -153,9 +145,9 @@ xnrealloc (void *p, size_t n, size_t s) void append_int (int value) { - if (used == allocated) - p = x2nrealloc (p, &allocated, sizeof *p); - p[used++] = 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 @@ -173,17 +165,17 @@ xnrealloc (void *p, size_t n, size_t s) void append_int (int value) { - if (used == allocated) - { - p = x2nrealloc (p, &allocated1, sizeof *p); - allocated = allocated1; - } - p[used++] = value; + if (used == allocated) + { + p = x2nrealloc (p, &allocated1, sizeof *p); + allocated = allocated1; + } + p[used++] = value; } */ -static_inline void * +XALLOC_INLINE void * x2nrealloc (void *p, size_t *pn, size_t s) { size_t n = *pn; @@ -191,22 +183,26 @@ x2nrealloc (void *p, size_t *pn, size_t s) if (! p) { if (! n) - { - /* The approximate size to use for initial small allocation - requests, when the invoking code specifies an old size of - zero. 64 bytes is the largest "small" request for the - GNU C library malloc. */ - enum { DEFAULT_MXFAST = 64 }; - - n = DEFAULT_MXFAST / s; - n += !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 { - if ((2 * (((size_t) -1 - 1) / 3)) / s < n) - xalloc_die (); - n = n + n / 2 + 1; + /* 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; @@ -216,15 +212,15 @@ x2nrealloc (void *p, size_t *pn, size_t s) /* Return a pointer to a new buffer of N bytes. This is like xmalloc, except it returns char *. */ -static_inline 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 - -# ifdef __cplusplus +#ifdef __cplusplus } /* C++ does not allow conversions from void * to other pointer types @@ -261,7 +257,7 @@ xmemdup (T const *p, size_t s) return (T *) xmemdup ((void const *) p, s); } -# endif +#endif #endif /* !XALLOC_H_ */