1 /* Safe automatic memory allocation with out of memory checking. 2 Copyright (C) 2003, 2005, 2007, 2009-2021 Free Software Foundation, Inc. 3 Written by Bruno Haible <bruno@clisp.org>, 2003. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 17 18 #ifndef _XMALLOCA_H 19 #define _XMALLOCA_H 20 21 #include "malloca.h" 22 #include "xalloc.h" 23 #include "xalloc-oversized.h" 24 25 26 #ifdef __cplusplus 27 extern "C" { 28 #endif 29 30 31 /* xmalloca(N) is a checking safe variant of alloca(N). It allocates N bytes 32 of memory allocated on the stack, that must be freed using freea() before 33 the function returns. N should not have side effects. 34 Upon failure, it exits with an error message. */ 35 #if HAVE_ALLOCA 36 # define xmalloca(N) \ 37 ((N) < 4032 - (2 * sa_alignment_max - 1) \ 38 ? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \ 39 + (2 * sa_alignment_max - 1)) \ 40 & ~(uintptr_t)(2 * sa_alignment_max - 1)) \ 41 : xmmalloca (N)) 42 extern void * xmmalloca (size_t n) 43 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (freea, 1) 44 _GL_ATTRIBUTE_ALLOC_SIZE ((1)) _GL_ATTRIBUTE_RETURNS_NONNULL; 45 #else 46 # define xmalloca(N) \ 47 xmalloc (N) 48 #endif 49 50 /* xnmalloca(N,S) is an overflow-safe variant of xmalloca (N * S). 51 It allocates an array of N objects, each with S bytes of memory, 52 on the stack. S must be positive and N must be nonnegative, 53 and S and N should not have side effects. 54 The array must be freed using freea() before the function returns. 55 Upon failure, it exits with an error message. */ 56 #if HAVE_ALLOCA 57 /* Rely on xmalloca (SIZE_MAX) calling xalloc_die (). */ 58 # define xnmalloca(n, s) \ 59 xmalloca (xalloc_oversized (n, s) ? (size_t) (-1) : (n) * (size_t) (s)) 60 #else 61 # define xnmalloca(n, s) \ 62 xnmalloc (n, s) 63 #endif 64 65 66 #ifdef __cplusplus 67 } 68 #endif 69 70 71 #endif /* _XMALLOCA_H */