X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fxalloc.h;h=c1bbe7e5b6cedda5e8e39b515fada57a40fc9f41;hb=8750d25d450a75684c2f29e2eea2467cea18f076;hp=459e37a0ed00d4dba405c133f12e7a3463d6e729;hpb=ac2a728a11acdae91051359487c52acc9d180a8e;p=gnulib.git diff --git a/lib/xalloc.h b/lib/xalloc.h index 459e37a0e..c1bbe7e5b 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 Free Software Foundation, Inc. + Copyright (C) 1990-2000, 2003-2004, 2006-2011 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 @@ -14,28 +13,36 @@ 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_ # include +# include "xalloc-oversized.h" # ifdef __cplusplus extern "C" { # endif -# ifndef __attribute__ -# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__ -# define __attribute__(x) -# endif +# if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8) +# define _GL_ATTRIBUTE_NORETURN __attribute__ ((__noreturn__)) +# else +# define _GL_ATTRIBUTE_NORETURN /* empty */ # endif -# ifndef ATTRIBUTE_NORETURN -# define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__)) +# if __GNUC__ >= 3 +# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) +# else +# define _GL_ATTRIBUTE_MALLOC +# 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. @@ -43,35 +50,68 @@ extern "C" { 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 void xalloc_die (void) _GL_ATTRIBUTE_NORETURN; + +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 + 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)))) + + +# if HAVE_INLINE +# define static_inline static inline +# else +void *xnmalloc (size_t n, size_t s) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2)); +void *xnrealloc (void *p, size_t n, size_t s) + _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3)); +void *x2nrealloc (void *p, size_t *pn, size_t s); +char *xcharalloc (size_t n) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1)); +# 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 * +static_inline void *xnmalloc (size_t n, size_t s) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2)); +static_inline void * xnmalloc (size_t n, size_t s) { if (xalloc_oversized (n, s)) @@ -82,7 +122,9 @@ 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 * +static_inline void *xnrealloc (void *p, size_t n, size_t s) + _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3)); +static_inline void * xnrealloc (void *p, size_t n, size_t s) { if (xalloc_oversized (n, s)) @@ -101,10 +143,10 @@ xnrealloc (void *p, size_t n, size_t s) allocating an initial block with a nonzero size, or by allocating a larger block. - In the following implementation, nonzero sizes are doubled so that - repeated reallocations have O(N log N) overall cost rather than - O(N**2) cost, but the specification for this function does not - guarantee that sizes are doubled. + 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: @@ -115,9 +157,9 @@ 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 @@ -135,17 +177,17 @@ 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 * +static_inline void * x2nrealloc (void *p, size_t *pn, size_t s) { size_t n = *pn; @@ -153,59 +195,45 @@ 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. 64 bytes is the largest "small" request for the + GNU C library malloc. */ + enum { DEFAULT_MXFAST = 64 }; + + n = DEFAULT_MXFAST / s; + n += !n; + } } else { - if (((size_t) -1) / 2 / s < n) - xalloc_die (); - n *= 2; + /* 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; return xrealloc (p, n * s); } -/* 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 *) 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 *) xcalloc (n, sizeof (t))) - /* Return a pointer to a new buffer of N bytes. This is like xmalloc, except it returns char *. */ -static inline char * + +static_inline char *xcharalloc (size_t n) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1)); +static_inline char * xcharalloc (size_t n) { return XNMALLOC (n, char); } +# endif + # ifdef __cplusplus }