46 lines
1.5 KiB
Text
46 lines
1.5 KiB
Text
# alloca.m4 serial 8
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dnl Copyright (C) 2002-2004, 2006, 2007 Free Software Foundation, Inc.
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dnl This file is free software; the Free Software Foundation
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dnl gives unlimited permission to copy and/or distribute it,
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dnl with or without modifications, as long as this notice is preserved.
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AC_DEFUN([gl_FUNC_ALLOCA],
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[
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dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
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AC_REQUIRE([AC_PROG_CPP])
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AC_REQUIRE([AC_PROG_EGREP])
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AC_REQUIRE([AC_FUNC_ALLOCA])
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if test $ac_cv_func_alloca_works = no; then
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gl_PREREQ_ALLOCA
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fi
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# Define an additional variable used in the Makefile substitution.
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if test $ac_cv_working_alloca_h = yes; then
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AC_CACHE_CHECK([for alloca as a compiler built-in], [gl_cv_rpl_alloca], [
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AC_EGREP_CPP([Need own alloca], [
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#if defined __GNUC__ || defined _AIX || defined _MSC_VER
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Need own alloca
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#endif
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], [gl_cv_rpl_alloca=yes], [gl_cv_rpl_alloca=no])
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])
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if test $gl_cv_rpl_alloca = yes; then
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dnl OK, alloca can be implemented through a compiler built-in.
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AC_DEFINE([HAVE_ALLOCA], 1,
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[Define to 1 if you have 'alloca' after including <alloca.h>,
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a header that may be supplied by this distribution.])
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ALLOCA_H=alloca.h
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else
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dnl alloca exists as a library function, i.e. it is slow and probably
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dnl a memory leak. Don't define HAVE_ALLOCA in this case.
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ALLOCA_H=
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fi
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else
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ALLOCA_H=alloca.h
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fi
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AC_SUBST([ALLOCA_H])
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])
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# Prerequisites of lib/alloca.c.
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# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.
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AC_DEFUN([gl_PREREQ_ALLOCA], [:])
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