release/src/router/libiconv/gnulib-local/lib/alloca.in.h

   1 /* Memory allocation on the stack.
   2    Copyright (C) 1995, 1999, 2001-2007 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* When this file is included, it may be preceded only by preprocessor
  18    declarations.  Thanks to AIX.  Therefore we include it right after
  19    "config.h", not later.  */
  20
  21 /* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H
  22    means there is a real alloca function.  */
  23 #ifndef _GL_ALLOCA_H
  24 #define _GL_ALLOCA_H
  25
  26 /* alloca(N) returns a pointer (void* or char*) to N bytes of memory
  27    allocated on the stack, and which will last until the function returns.
  28    Use of alloca should be avoided:
  29      - inside arguments of function calls - undefined behaviour,
  30      - in inline functions - the allocation may actually last until the
  31        calling function returns,
  32      - for huge N (say, N >= 65536) - you never know how large (or small)
  33        the stack is, and when the stack cannot fulfill the memory allocation
  34        request, the program just crashes.
  35  */
  36
  37 #ifndef alloca
  38 # ifdef __GNUC__
  39 #   define alloca __builtin_alloca
  40 # else
  41 #  ifdef _MSC_VER
  42 #   include <malloc.h>
  43 #   define alloca _alloca
  44 #  else
  45 #   if HAVE_ALLOCA_H
  46 #    include <alloca.h>
  47 #   else
  48 #    ifdef _AIX
  49  #pragma alloca
  50 #    else
  51 #     ifdef __hpux /* This section must match that of bison generated files. */
  52 #      ifdef __cplusplus
  53 extern "C" void *alloca (unsigned int);
  54 #      else /* not __cplusplus */
  55 extern void *alloca ();
  56 #      endif /* not __cplusplus */
  57 #     else /* not __hpux */
  58 #      ifndef alloca
  59 extern char *alloca ();
  60 #      endif
  61 #     endif /* __hpux */
  62 #    endif
  63 #   endif
  64 #  endif
  65 # endif
  66 #endif
  67
  68 #endif /* _GL_ALLOCA_H */