| 1 | # alloca.m4 serial 7
|
|---|
| 2 | dnl Copyright (C) 2002-2004, 2006 Free Software Foundation, Inc.
|
|---|
| 3 | dnl This file is free software; the Free Software Foundation
|
|---|
| 4 | dnl gives unlimited permission to copy and/or distribute it,
|
|---|
| 5 | dnl with or without modifications, as long as this notice is preserved.
|
|---|
| 6 |
|
|---|
| 7 | AC_DEFUN([gl_FUNC_ALLOCA],
|
|---|
| 8 | [
|
|---|
| 9 | dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
|
|---|
| 10 | AC_REQUIRE([AC_PROG_CPP])
|
|---|
| 11 | AC_REQUIRE([AC_PROG_EGREP])
|
|---|
| 12 |
|
|---|
| 13 | AC_REQUIRE([AC_FUNC_ALLOCA])
|
|---|
| 14 | if test $ac_cv_func_alloca_works = no; then
|
|---|
| 15 | gl_PREREQ_ALLOCA
|
|---|
| 16 | fi
|
|---|
| 17 |
|
|---|
| 18 | # Define an additional variable used in the Makefile substitution.
|
|---|
| 19 | if test $ac_cv_working_alloca_h = yes; then
|
|---|
| 20 | AC_CACHE_CHECK([for alloca as a compiler built-in], [gl_cv_rpl_alloca], [
|
|---|
| 21 | AC_EGREP_CPP([Need own alloca], [
|
|---|
| 22 | #if defined __GNUC__ || defined _AIX || defined _MSC_VER
|
|---|
| 23 | Need own alloca
|
|---|
| 24 | #endif
|
|---|
| 25 | ], [gl_cv_rpl_alloca=yes], [gl_cv_rpl_alloca=no])
|
|---|
| 26 | ])
|
|---|
| 27 | if test $gl_cv_rpl_alloca = yes; then
|
|---|
| 28 | dnl OK, alloca can be implemented through a compiler built-in.
|
|---|
| 29 | AC_DEFINE([HAVE_ALLOCA], 1,
|
|---|
| 30 | [Define to 1 if you have 'alloca' after including <alloca.h>,
|
|---|
| 31 | a header that may be supplied by this distribution.])
|
|---|
| 32 | ALLOCA_H=alloca.h
|
|---|
| 33 | else
|
|---|
| 34 | dnl alloca exists as a library function, i.e. it is slow and probably
|
|---|
| 35 | dnl a memory leak. Don't define HAVE_ALLOCA in this case.
|
|---|
| 36 | ALLOCA_H=
|
|---|
| 37 | fi
|
|---|
| 38 | else
|
|---|
| 39 | ALLOCA_H=alloca.h
|
|---|
| 40 | fi
|
|---|
| 41 | AC_SUBST([ALLOCA_H])
|
|---|
| 42 |
|
|---|
| 43 | AC_DEFINE(HAVE_ALLOCA_H, 1,
|
|---|
| 44 | [Define HAVE_ALLOCA_H for backward compatibility with older code
|
|---|
| 45 | that includes <alloca.h> only if HAVE_ALLOCA_H is defined.])
|
|---|
| 46 | ])
|
|---|
| 47 |
|
|---|
| 48 | # Prerequisites of lib/alloca.c.
|
|---|
| 49 | # STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.
|
|---|
| 50 | AC_DEFUN([gl_PREREQ_ALLOCA], [:])
|
|---|
