EVOLUTION-NINJA

Edit File: malloca.h

/* Safe automatic memory allocation. Copyright (C) 2003-2007, 2009-2013 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2003. 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, 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 <http://www.gnu.org/licenses/>. */ #ifndef _MALLOCA_H #define _MALLOCA_H #include <alloca.h> #include <stddef.h> #include <stdlib.h> #ifdef __cplusplus extern "C" { #endif /* safe_alloca(N) is equivalent to alloca(N) when it is safe to call alloca(N); otherwise it returns NULL. It either returns N bytes of memory allocated on the stack, that lasts until the function returns, or NULL. Use of safe_alloca should be avoided: - inside arguments of function calls - undefined behaviour, - in inline functions - the allocation may actually last until the calling function returns. */ #if HAVE_ALLOCA /* The OS usually guarantees only one guard page at the bottom of the stack, and a page size can be as small as 4096 bytes. So we cannot safely allocate anything larger than 4096 bytes. Also care for the possibility of a few compiler-allocated temporary stack slots. This must be a macro, not a function. */ # define safe_alloca(N) ((N) < 4032 ? alloca (N) : NULL) #else # define safe_alloca(N) ((void) (N), NULL) #endif /* malloca(N) is a safe variant of alloca(N). It allocates N bytes of memory allocated on the stack, that must be freed using freea() before the function returns. Upon failure, it returns NULL. */ #if HAVE_ALLOCA # define malloca(N) \ ((N) < 4032 - sa_increment \ ? (void *) ((char *) alloca ((N) + sa_increment) + sa_increment) \ : mmalloca (N)) #else # define malloca(N) \ mmalloca (N) #endif extern void * mmalloca (size_t n); /* Free a block of memory allocated through malloca(). */ #if HAVE_ALLOCA extern void freea (void *p); #else # define freea free #endif /* nmalloca(N,S) is an overflow-safe variant of malloca (N * S). It allocates an array of N objects, each with S bytes of memory, on the stack. S must be positive and N must be nonnegative. The array must be freed using freea() before the function returns. */ #if 1 /* Cf. the definition of xalloc_oversized. */ # define nmalloca(n, s) \ ((n) > (size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) \ ? NULL \ : malloca ((n) * (s))) #else extern void * nmalloca (size_t n, size_t s); #endif #ifdef __cplusplus } #endif /* ------------------- Auxiliary, non-public definitions ------------------- */ /* Determine the alignment of a type at compile time. */ #if defined __GNUC__ || defined __IBM__ALIGNOF__ # define sa_alignof __alignof__ #elif defined __cplusplus template <class type> struct sa_alignof_helper { char __slot1; type __slot2; }; # define sa_alignof(type) offsetof (sa_alignof_helper<type>, __slot2) #elif defined __hpux /* Work around a HP-UX 10.20 cc bug with enums constants defined as offsetof values. */ # define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8) #elif defined _AIX /* Work around an AIX 3.2.5 xlc bug with enums constants defined as offsetof values. */ # define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8) #else # define sa_alignof(type) offsetof (struct { char __slot1; type __slot2; }, __slot2) #endif enum { /* The desired alignment of memory allocations is the maximum alignment among all elementary types. */ sa_alignment_long = sa_alignof (long), sa_alignment_double = sa_alignof (double), #if HAVE_LONG_LONG_INT sa_alignment_longlong = sa_alignof (long long), #endif sa_alignment_longdouble = sa_alignof (long double), sa_alignment_max = ((sa_alignment_long - 1) | (sa_alignment_double - 1) #if HAVE_LONG_LONG_INT | (sa_alignment_longlong - 1) #endif | (sa_alignment_longdouble - 1) ) + 1, /* The increment that guarantees room for a magic word must be >= sizeof (int) and a multiple of sa_alignment_max. */ sa_increment = ((sizeof (int) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max }; #endif /* _MALLOCA_H */