c.at

autoconf是一个产生可以自动配置源代码包

#							-*- Autotest -*-

AT_BANNER([C low level compiling/preprocessing macros.])

# Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
# Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


# Since the macros which compile are required by most tests, check
# them first.  But remember that looking for a compiler is even more
# primitive, so check those first.


## ------------ ##
## Extensions.  ##
## ------------ ##

# As far as we know only `foo', `foo.exe' are possible executable,
# and `foo.o', `foo.obj' are possible object files.  Autoconf must not
# know that, but it is OK for the test suite to take this into account.
AT_CHECK_MACRO([Extensions],
[[AC_PROG_CC
case $ac_exeext in
  '' | '.exe' ) ;;
  * ) AC_MSG_ERROR([suspicious executable suffix: $ac_exeext]);;
esac

case $ac_objext in
  'o' | 'obj' ) ;;
  * ) AC_MSG_ERROR([suspicious object suffix: $ac_objext]);;
esac
]])



## -------------------------- ##
## Broken/missing compilers.  ##
## -------------------------- ##


# Check that Autoconf correctly diagnoses broken compilers, and in
# particular, if it does not exit 77, the test suite is in trouble...
# FIXME: Once a precise message decided, check stderr of configure.
AT_SETUP([Broken/missing compilers])

AT_DATA([configure.ac],
[[AC_INIT
CC=no-such-compiler
AC_PROG_CC
]])

AT_CHECK_AUTOCONF
AT_CHECK_CONFIGURE([], 77, ignore, ignore)

AT_CLEANUP


## ------------ ##
## C keywords.  ##
## ------------ ##

# GCC supports `const', `typeof', and `volatile'.
AT_CHECK_MACRO([C keywords],
[[AC_PROG_CC
AC_C_CONST
AC_C_TYPEOF
AC_C_VOLATILE
case $GCC,$ac_cv_c_const,$ac_cv_c_typeof,$ac_cv_c_volatile in
 yes,*no*)
   AC_MSG_ERROR([failed to detect `const', `typeof', or `volatile' support]);;
esac
]])



## --------------------------------- ##
## AC_PROG_CPP requires AC_PROG_CC.  ##
## --------------------------------- ##

# Must invoke AC_PROG_CC.
AT_CHECK_MACRO([AC_PROG_CPP requires AC_PROG_CC],
[[AC_PROG_CPP
test -z "$CC" &&
   AC_MSG_ERROR([looked for a C preprocessor without looking for a compiler])
]])



## --------------------------- ##
## AC_PROG_CPP with warnings.  ##
## --------------------------- ##


# It's Ok for strict preprocessors to produce warnings.

AT_SETUP([AC_PROG_CPP with warnings])

AT_DATA([mycpp],
[[#! /bin/sh
echo noise >&2
exec "$@"
]])

chmod +x mycpp

_AT_CHECK_AC_MACRO(
[[AC_PROG_CPP
# If the preprocessor is not strict, just ignore
test "x$ac_c_preproc_warn_flag" = xyes &&
  AC_MSG_ERROR([preprocessor has no warning option], 77)
CPP="./mycpp $CPP"
AC_CHECK_HEADERS(stdio.h autoconf_io.h)]])

AT_CHECK_DEFINES(
[/* #undef HAVE_AUTOCONF_IO_H */
#define HAVE_STDIO_H 1
])

AT_CLEANUP


## ------------------------------ ##
## AC_PROG_CPP without warnings.  ##
## ------------------------------ ##

AT_SETUP([AC_PROG_CPP without warnings])

# Ignore if /lib/cpp doesn't work
AT_CHECK([echo '#include <stdio.h>' | /lib/cpp || exit 77],
  [], [ignore], [ignore])

# A cpp which exit status is meaningless.
AT_DATA([mycpp],
[[#! /bin/sh
/lib/cpp "$@"
exit 0
]])

chmod +x mycpp

_AT_CHECK_AC_MACRO(
[[CPP=./mycpp
AC_PROG_CPP
test "x$ac_c_preproc_warn_flag" != xyes &&
  AC_MSG_ERROR([failed to detect preprocessor warning option])
AC_CHECK_HEADERS(stdio.h autoconf_io.h)]])

AT_CHECK_DEFINES(
[/* #undef HAVE_AUTOCONF_IO_H */
#define HAVE_STDIO_H 1
])

AT_CLEANUP



## -------------------- ##
## AC_PROG_CPP via CC.  ##
## -------------------- ##


# It's Ok for strict preprocessors to produce warnings.

AT_SETUP([AC_PROG_CPP via CC])

# Ignore if /lib/cpp doesn't work
AT_CHECK([echo '#include <stdio.h>' | /lib/cpp || exit 77],
  [], [ignore], [ignore])

AT_DATA([mycc],
[[#! /bin/sh
echo "Annoying copyright message" >&2
exec "$@"
]])

chmod +x mycc

# We go through the following contortions, in order to have the
# configure script go down the same codepaths as it would during a
# normal CPP selection check.  If we explicitly set CPP, it goes down
# a different codepath.
_AT_CHECK_AC_MACRO(
[[AC_PROG_CC
CC="./mycc $CC"
AC_PROG_CPP
# The test $CC compiler should have been selected.
test "$CPP" != "$CC -E" &&
  AC_MSG_ERROR([error messages on stderr cause the preprocessor selection to fail])

# Exercise CPP.
AC_CHECK_HEADERS(stdio.h autoconf_io.h)]])

AT_CHECK_DEFINES(
[/* #undef HAVE_AUTOCONF_IO_H */
#define HAVE_STDIO_H 1
])

AT_CLEANUP