| 1 | /* Memory allocation on the stack.
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| 2 |
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| 3 | Copyright (C) 1995, 1999, 2001-2004, 2006-2022 Free Software Foundation,
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| 4 | Inc.
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| 5 |
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| 6 | This file is free software: you can redistribute it and/or modify
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| 7 | it under the terms of the GNU Lesser General Public License as
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| 8 | published by the Free Software Foundation; either version 2.1 of the
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| 9 | License, or (at your option) any later version.
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| 10 |
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| 11 | This file is distributed in the hope that it will be useful,
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 14 | GNU Lesser General Public License for more details.
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| 15 |
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| 16 | You should have received a copy of the GNU Lesser General Public License
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| 17 | along with this program. If not, see <https://www.gnu.org/licenses/>. */
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| 18 |
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| 19 | /* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H
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| 20 | means there is a real alloca function. */
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| 21 | #ifndef _GL_ALLOCA_H
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| 22 | #define _GL_ALLOCA_H
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| 23 |
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| 24 | /* alloca (N) returns a pointer to N bytes of memory
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| 25 | allocated on the stack, which will last until the function returns.
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| 26 | Use of alloca should be avoided:
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| 27 | - inside arguments of function calls - undefined behaviour,
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| 28 | - in inline functions - the allocation may actually last until the
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| 29 | calling function returns,
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| 30 | - for huge N (say, N >= 65536) - you never know how large (or small)
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| 31 | the stack is, and when the stack cannot fulfill the memory allocation
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| 32 | request, the program just crashes.
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| 33 | */
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| 34 |
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| 35 | #ifndef alloca
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| 36 | /* Some version of mingw have an <alloca.h> that causes trouble when
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| 37 | included after 'alloca' gets defined as a macro. As a workaround,
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| 38 | include this <alloca.h> first and define 'alloca' as a macro afterwards
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| 39 | if needed. */
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| 40 | # if defined __GNUC__ && (defined _WIN32 && ! defined __CYGWIN__) && @HAVE_ALLOCA_H@
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| 41 | # include_next <alloca.h>
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| 42 | # endif
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| 43 | #endif
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| 44 | #ifndef alloca
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| 45 | # if defined __GNUC__ || (__clang_major__ >= 4)
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| 46 | # define alloca __builtin_alloca
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| 47 | # elif defined _AIX
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| 48 | # define alloca __alloca
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| 49 | # elif defined _MSC_VER
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| 50 | # include <malloc.h>
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| 51 | # define alloca _alloca
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| 52 | # elif defined __DECC && defined __VMS
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| 53 | # define alloca __ALLOCA
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| 54 | # elif defined __TANDEM && defined _TNS_E_TARGET
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| 55 | # ifdef __cplusplus
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| 56 | extern "C"
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| 57 | # endif
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| 58 | void *_alloca (unsigned short);
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| 59 | # pragma intrinsic (_alloca)
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| 60 | # define alloca _alloca
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| 61 | # elif defined __MVS__
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| 62 | # include <stdlib.h>
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| 63 | # else
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| 64 | # include <stddef.h>
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| 65 | # ifdef __cplusplus
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| 66 | extern "C"
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| 67 | # endif
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| 68 | void *alloca (size_t);
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| 69 | # endif
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| 70 | #endif
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| 71 |
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| 72 | #endif /* _GL_ALLOCA_H */
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