no AC_LANG_SOURCE call detected in body with AC_RUN_IFELSE+AC_LANG_PROGRAM

[Vincent Lefevre]

Hi,

On a Debian/sid machine, with the following configure.ac

AC_INIT([Test], [1.0])
AC_RUN_IFELSE(AC_LANG_PROGRAM([[ ]], [[ ]]),
  [AC_MSG_RESULT(yes)], [AC_MSG_RESULT(no)], [AC_MSG_RESULT(can not test)])

autoconf version 2.68 gives:

configure.ac:2: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in 
body
../../lib/autoconf/lang.m4:194: AC_LANG_CONFTEST is expanded from...
../../lib/autoconf/general.m4:2730: _AC_RUN_IFELSE is expanded from...
../../lib/m4sugar/m4sh.m4:606: AS_IF is expanded from...
../../lib/autoconf/general.m4:2749: AC_RUN_IFELSE is expanded from...
configure.ac:2: the top level

According to the autoconf manual, the use of AC_LANG_PROGRAM is
correct and the AC_RUN_IFELSE description says:

  The INPUT can be made by `AC_LANG_PROGRAM' and friends.

So, I don't see anything wrong with the above example.

http://www.mail-archive.com/address@hidden/msg03053.html says,
from the NEWS file:

** The macros AC_PREPROC_IFELSE, AC_COMPILE_IFELSE, AC_LINK_IFELSE, and
   AC_RUN_IFELSE now warn if the first argument failed to use
   AC_LANG_SOURCE or AC_LANG_PROGRAM to generate the conftest file
   contents.  A new macro AC_LANG_DEFINES_PROVIDED exists if you have
   a compelling reason why you cannot use AC_LANG_SOURCE but must
   avoid the warning.

but since the example uses AC_LANG_PROGRAM, this should be OK.

There was no such problem with previous autoconf versions (though
I had not tried on this example, but on MPFR).

Regards,

-- 
Vincent Lefèvre <address@hidden> - Web: <http://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)