Re: [Autoconf] Re: Libtool warning message

[Pavel Roskin]

Hello, Gary and Bob!

> > checking whether a program can dlopen itself... cat: cannot open conftest.cc
> > no
> 
> This looks like a problem in AC_TRY_RUN from cvs autoconf to me.  Are

Words "dlopen itself" come from ltconfig.in. If you look around those
words, you will find an excellent example of a wrong assumption:

cat > conftest.c <<EOF

conftest.c is also used while "checking whether a statically linked
program can dlopen itself"

This patch fixes everything and works both with Autoconf 2.13 anf the CVS
version:

=================
Index: ltconfig.in
--- ltconfig.in Fri Sep 15 12:49:03 2000
+++ ltconfig.in Sat Sep 16 23:57:38 2000
@@ -1795,7 +1795,7 @@
   if test "$cross_compiling" = yes; then
     lt_cv_dlopen_self=cross
   else
-    cat > conftest.c <<EOF
+    cat > conftest.$ac_ext <<EOF
 #line @LINENO@ "ltconfig"
 
 #if HAVE_DLFCN_H
@@ -1868,7 +1868,7 @@
   if test "$cross_compiling" = yes; then
     lt_cv_dlopen_self_static=cross
   else
-    cat > conftest.c <<EOF
+    cat > conftest.$ac_ext <<EOF
 #line @LINENO@ "ltconfig"
 
 #if HAVE_DLFCN_H
=================

> To be sure, could you try it again with autoconf-2.13 and see whether
> it goes away, please?

Yes, it does. Which means that ltconfig is run with the C language active
when Autoconf-2.13 is used. For Autoconf-2.49a the current language is
C++. I tried this on libtool itself.

I don't know what language should be active when ltconfig is run. However,
if you search for "sco3.2v5" in libtool.m4 you will find an explicit
AC_LANG_C in AC_LIBTOOL_SETUP, which _probably_ means that running
ltconfig in the C++ mode is not ruled out.

Otherwise, you need a check in ltconfig.in that the current language is C
and nothing else. You may also need to use AC_LANG_C not only for
"sco3.2v5"

Regards,
Pavel Roskin