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73 lines
2.4 KiB
C
73 lines
2.4 KiB
C
/* Memory allocation on the stack.
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Copyright (C) 1995, 1999, 2001-2004, 2006-2024 Free Software Foundation,
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Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H
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means there is a real alloca function. */
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#ifndef _GL_ALLOCA_H
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#define _GL_ALLOCA_H
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/* alloca (N) returns a pointer to N bytes of memory
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allocated on the stack, which will last until the function returns.
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Use of alloca should be avoided:
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- inside arguments of function calls - undefined behaviour,
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- in inline functions - the allocation may actually last until the
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calling function returns,
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- for huge N (say, N >= 65536) - you never know how large (or small)
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the stack is, and when the stack cannot fulfill the memory allocation
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request, the program just crashes.
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*/
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#ifndef alloca
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/* Some version of mingw have an <alloca.h> that causes trouble when
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included after 'alloca' gets defined as a macro. As a workaround,
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include this <alloca.h> first and define 'alloca' as a macro afterwards
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if needed. */
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# if defined __GNUC__ && (defined _WIN32 && ! defined __CYGWIN__) && @HAVE_ALLOCA_H@
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# include_next <alloca.h>
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# endif
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#endif
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#ifndef alloca
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# if defined __GNUC__ || (__clang_major__ >= 4)
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# define alloca __builtin_alloca
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# elif defined _AIX
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# define alloca __alloca
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# elif defined _MSC_VER
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# include <malloc.h>
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# define alloca _alloca
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# elif defined __DECC && defined __VMS
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# define alloca __ALLOCA
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# elif defined __TANDEM && defined _TNS_E_TARGET
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# ifdef __cplusplus
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extern "C"
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# endif
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void *_alloca (unsigned short);
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# pragma intrinsic (_alloca)
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# define alloca _alloca
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# elif defined __MVS__
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# include <stdlib.h>
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# else
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# include <stddef.h>
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# ifdef __cplusplus
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extern "C"
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# endif
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void *alloca (size_t);
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# endif
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#endif
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#endif /* _GL_ALLOCA_H */
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