X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxmalloc.c;h=181006b43dbc69e40a1d6d5f167093074fe751b9;hb=9b9bfb49af70f53f177c7a6563fa844a4a50c7db;hp=22b09102184a4efb20004c668c8c1fcf23293c89;hpb=2753afe57a2f829b9bc54d4e0271a3838342aaf1;p=gnulib.git diff --git a/lib/xmalloc.c b/lib/xmalloc.c index 22b091021..181006b43 100644 --- a/lib/xmalloc.c +++ b/lib/xmalloc.c @@ -1,5 +1,7 @@ /* xmalloc.c -- malloc with out of memory checking - Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc. + + Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2003, + 1999, 2000, 2002, 2003 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 @@ -19,117 +21,235 @@ # include #endif -#include +#include "xalloc.h" -#if STDC_HEADERS -# include -#else -void *calloc (); -void *malloc (); -void *realloc (); -void free (); -#endif +#include +#include -#if ENABLE_NLS -# include -# define _(Text) gettext (Text) -#else -# define textdomain(Domain) -# define _(Text) Text -#endif -#define N_(Text) Text +#include "gettext.h" +#define _(msgid) gettext (msgid) +#define N_(msgid) msgid #include "error.h" -#include "xalloc.h" +#include "exitfail.h" -#ifndef EXIT_FAILURE -# define EXIT_FAILURE 1 +#ifndef SIZE_MAX +# define SIZE_MAX ((size_t) -1) #endif -/* Prototypes for functions defined here. */ -#if defined (__STDC__) && __STDC__ -static void *fixup_null_alloc (size_t n); -void *xmalloc (size_t n); -void *xcalloc (size_t n, size_t s); -void *xrealloc (void *p, size_t n); +#ifndef HAVE_MALLOC +"you must run the autoconf test for a GNU libc compatible malloc" #endif +#ifndef HAVE_REALLOC +"you must run the autoconf test for a GNU libc compatible realloc" +#endif -/* Exit value when the requested amount of memory is not available. - The caller may set it to some other value. */ -int xalloc_exit_failure = EXIT_FAILURE; +/* If non NULL, call this function when memory is exhausted. */ +void (*xalloc_fail_func) (void) = 0; -/* FIXME: describe */ -char *const xalloc_msg_memory_exhausted = N_("Memory exhausted"); +/* If XALLOC_FAIL_FUNC is NULL, or does return, display this message + before exiting when memory is exhausted. Goes through gettext. */ +char const xalloc_msg_memory_exhausted[] = N_("memory exhausted"); -/* FIXME: describe */ -void (*xalloc_fail_func) () = NULL; +void +xalloc_die (void) +{ + if (xalloc_fail_func) + (*xalloc_fail_func) (); + error (exit_failure, 0, "%s", _(xalloc_msg_memory_exhausted)); + /* The `noreturn' cannot be given to error, since it may return if + its first argument is 0. To help compilers understand the + xalloc_die does terminate, call abort. */ + abort (); +} -#if __STDC__ && (HAVE_VPRINTF || HAVE_DOPRNT) -void error (int, int, const char *, ...); -#else -void error (); -#endif +/* Allocate an array of N objects, each with S bytes of memory, + dynamically, with error checking. S must be nonzero. */ -static void * -fixup_null_alloc (n) - size_t n; +static inline void * +xnmalloc_inline (size_t n, size_t s) { void *p; - - p = 0; - if (n == 0) - p = malloc ((size_t) 1); - if (p == 0) - { - if (xalloc_fail_func) - (*xalloc_fail_func) (); - error (xalloc_exit_failure, 0, xalloc_msg_memory_exhausted); - } + if (xalloc_oversized (n, s) || ! (p = malloc (n * s))) + xalloc_die (); return p; } +void * +xnmalloc (size_t n, size_t s) +{ + return xnmalloc_inline (n, s); +} + /* Allocate N bytes of memory dynamically, with error checking. */ void * -xmalloc (n) - size_t n; +xmalloc (size_t n) { - void *p; + return xnmalloc_inline (n, 1); +} + +/* 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. */ - p = malloc (n); - if (p == 0) - p = fixup_null_alloc (n); +static inline void * +xnrealloc_inline (void *p, size_t n, size_t s) +{ + if (xalloc_oversized (n, s) || ! (p = realloc (p, n * s))) + xalloc_die (); return p; } -/* Allocate memory for N elements of S bytes, with error checking. */ +void * +xnrealloc (void *p, size_t n, size_t s) +{ + return xnrealloc_inline (p, n, s); +} + +/* Change the size of an allocated block of memory P to N bytes, + with error checking. */ void * -xcalloc (n, s) - size_t n, s; +xrealloc (void *p, size_t n) { - void *p; + return xnrealloc_inline (p, n, 1); +} - p = calloc (n, s); - if (p == 0) - p = fixup_null_alloc (n); - return p; + +/* 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. *PN must be nonzero unless P is null, and 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 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. + + 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; + } + + */ + +static inline void * +x2nrealloc_inline (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. 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_MAX / 2 / s < n) + xalloc_die (); + n *= 2; + } + + *pn = n; + return xrealloc (p, n * s); } -/* Change the size of an allocated block of memory P to N bytes, - with error checking. - If P is NULL, run xmalloc. */ +void * +x2nrealloc (void *p, size_t *pn, size_t s) +{ + return x2nrealloc_inline (p, pn, s); +} + +/* 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_inline (p, pn, 1); +} + +/* Allocate S 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 s) +{ + return memset (xmalloc (s), 0, s); +} + +/* Allocate zeroed memory for N elements of S bytes, with error + checking. S must be nonzero. */ void * -xrealloc (p, n) - void *p; - size_t n; +xcalloc (size_t n, size_t s) { - if (p == 0) - return xmalloc (n); - p = realloc (p, n); - if (p == 0) - p = fixup_null_alloc (n); + void *p; + /* Test for overflow, since some calloc implementations don't have + proper overflow checks. */ + if (xalloc_oversized (n, s) || ! (p = calloc (n, s))) + xalloc_die (); return p; } + +/* Clone an object P of size S, with error checking. There's no need + for xnclone (P, N, S), since xclone (P, N * S) works without any + need for an arithmetic overflow check. */ + +void * +xclone (void const *p, size_t s) +{ + return memcpy (xmalloc (s), p, s); +}